Drill bit and drilling system comprising such a drill bit

Abstract

The invention relates to a drill head, which in operation can be rotated about an axis of rotation and whose effective drilling diameter can be enlarged, having a base body comprising an end side equipped with at least one cutting tool, and at least one expansion arm coupled to the base body in a pivotable manner about a pivot axis and pivotable between a retracted position and a first deployed position, which enlarges the effective drilling diameter by a first amount, wherein the at least one expansion arm comprises an active side equipped with at least one cutting tool, which in the retracted position of the at least one expansion arm lies at least approximately on one plane with the end side of the base body, and in the first deployed position of the at least one expansion arm extends from the end side of the base body in a manner that is at least approximately free of a step offset in the direction of the axis of rotation.

Description

[0001] This invention application is a divisional application of the invention patent application filed on March 8, 2019, with application number "201980017618.X" and invention title "Drill Bit and Drilling System Including Such Drill Bit". Technical Field

[0002] The present invention relates to a drill bit that is rotatable about a rotation axis during operation and whose effective drilling diameter is enlarged. The drill bit has: a base including an end side equipped with at least one cutting tool; and at least one extension arm that is pivotally coupled to the base about a pivot axis and pivotable between a retracted position and a first extended position, the first extended position increasing the effective drilling diameter by a first amount, wherein the extension arm includes an active side equipped with at least one cutting tool. Background Technology

[0003] Drill bits with these characteristics are known from KR 20060006754. In the retracted position, at least one cutting tool of the extended arm is inactive; in the extended position, the diameter of the borehole drilled during operation by means of the base expands immediately following the bottom of the borehole.

[0004] This type of drill bit is used, for example, in drilling holes in offshore bases for wind power equipment.

[0005] To improve the performance of wind power equipment, especially as part of so-called "offshore wind farms," ​​there is a trend towards increasingly larger wind turbines. Therefore, the foundations for these wind turbines must be designed to withstand these ever-increasing loads.

[0006] To meet this requirement, it is known, for example, to provide multiple, such as three, piles arranged in a triangle as bases for wind turbines, said piles being sunk into the seabed and protruding above the water surface. The upper ends of these piles are connected to each other via a load-bearing structure, to which the lower end of the wind turbine tower is anchored. These bases, also known as "tripods," also have the disadvantage of increasing the required installation costs due to the need for numerous foundation drillings.

[0007] Therefore, many wind turbines are currently used in nearshore areas, with their towers anchored to the upper end of a single pile foundation (also known as a "monopile"). To achieve the required stability of these pile foundations, the foundation has a larger diameter in the underwater region than the diameter of the corresponding upper end to which the wind turbine tower is anchored. Thus, these pile foundations typically include a "bottleneck" through which two regions of different diameters transition into each other.

[0008] To lower these pile foundations, it is typically necessary to drill a hole in the seabed within the pile. This requires inserting a drill bit from above into the interior of the pile foundation through a small-diameter area. Therefore, a drill bit of the type described at the beginning is required, whose effective borehole diameter is scalable. Summary of the Invention

[0009] The purpose of this invention is to provide a drill bit that is improved for a specified application.

[0010] The objective is achieved by a drill bit that is rotatable about a rotation axis during operation and whose effective bore diameter is enlarged. The drill bit has: a base including an end side equipped with at least one first cutting tool; and at least one extension arm that is pivotally coupled to the base about a pivot axis and pivotable between a retracted position and a first extended position, the first extended position increasing the effective bore diameter by a first amount. The at least one extension arm includes an active side equipped with at least one second cutting tool. In the retracted position, the active side and the end side of the base are at least approximately in the same plane. In the first extended position, the active side extends from the end side of the base with at least approximately no step offset in the direction of the rotation axis. The at least one extension arm is pivotable to a second extended position, the second extended position increasing the effective bore diameter by a second amount.

[0011] According to the invention, the drill bit is configured such that the working side of the extender arm, in the retracted position, is at least approximately in the same plane as the end side of the base. "At least approximately" is understood to mean that there should be no stepped offset between the working side of the extender arm and the end side of the base that is greater than the extension of the cutting tool along the axis of rotation.

[0012] Due to this configuration, in the drill bit according to the invention, at least one cutting tool of at least one extended arm is also capable of removing soil at the bottom of the borehole in its retracted position. Therefore, the drilling power achievable with the drill bit according to the invention is increased compared to prior art drill bits, in which at least one cutting tool of at least one extended arm is inactive in its retracted position.

[0013] The drill bit according to the invention is further configured such that, in the first extended position of the extended arm, the working side is connected to the end side of the base in a manner that is at least approximately stepless offset in the direction of the rotation axis.

[0014] "At least approximately stepless offset" means that the step offset should not exceed the extension of the cutting tool in the direction of the rotation axis. Stepless offset does not mean that the working side and the end side must be oriented parallel to each other. Rather, the working side can be tilted relative to the end side.

[0015] Due to this configuration, at least one cutting tool of at least one extended arm operates in a first deployed position in a plane that enters the plane in which at least one cutting tool of the base operates with at least approximately no step offset. Therefore, when drilling a hole using the extended arm in the first deployed position, a hole bottom without a horizontal step offset of the enlarged diameter can be achieved; however, the area at the hole bottom provided by at least one extended arm can be inclined relative to the area provided by the base.

[0016] In boreholes drilled using this type of drill bit, the area at the bottom of the borehole that is advanced by the drill bit's body precedes the area advanced by the extension arm. However, since this is not necessary for the excavation of the pile foundation, the increased cost of this type of drill bit is avoided by the avoidable drilling time and the amount of drill cuttings to be removed, which is avoided by the drill bit according to the invention.

[0017] In a preferred improvement of the drill bit according to the invention, at least one extension arm is pivotable to a second deployed position, which increases the effective borehole diameter of the drill bit by a second amount. This configuration of the drill bit allows for the initial advancement of the borehole through the interior of the pile foundation to its lower end by increasing the effective borehole diameter by a first amount, followed by further advancement by increasing the effective borehole diameter by a second amount. Therefore, it is easier to advance the pile foundation to the desired final depth. For this purpose, the effective borehole diameter increased by the second amount is preferably selected such that it at least corresponds to the outer diameter of the pile foundation.

[0018] In another preferred embodiment of the drill bit according to the invention, in the first and / or second extended positions, the working side of at least one extended arm is inclined at an angle of 20° to 45° relative to the end side of the base. Due to this measure, the area at the bottom of the borehole provided by at least one extended arm rises at approximately the same angle relative to the area provided by the base. Surprisingly, in this way, loose drill cuttings can be carried away from the bottom of the borehole particularly effectively, thereby reducing drill bit friction during downward drilling. Therefore, this preferred embodiment is characterized by particularly low energy requirements for downward drilling and particularly low wear on the drill bit, and especially on the cutting tool.

[0019] In another preferred embodiment of the drill bit according to the invention, a closing element is provided that at least substantially closes the void surface generated between the end side and the working side in the first and / or second extended positions of the extender arm. This prevents drill cuttings from entering a region of the drill bit through the void surface that prevents at least one extender arm from moving back to its retracted position, which could make it difficult or even impossible to remove the drill bit from the borehole.

[0020] In a preferred embodiment of the drill bit according to the invention, at least one extended arm has a side facing the axis of rotation of the drill bit. In the region of this side, a first end of an operating lever is hinged to the extended arm in a manner movable about an axis extending substantially parallel to the pivot axis, wherein a second end of the operating lever is movably hinged to the base along a guide portion extending transversely to the axis. Due to this design, at least one extended arm is coupled to the base in a particularly stable manner, such that even when drilling through rock, the forces acting on at least one extended arm in the first or second extended position can be introduced into the base without damage.

[0021] To allow at least one extender arm to move between a retracted position and a first and / or second extended position, a linear motor is preferably provided, which is hinged to the base via a first end and to the operating lever via a second end. The term "linear motor" should not be construed as limited to an electric motor, but should be interpreted broadly. In particular, it should also be understood here as a hydraulic or pneumatic cylinder. In a particularly preferred embodiment of the drill bit according to the invention, a hydraulic cylinder is provided, which is hinged to the base via a first end and to the operating lever via a second end.

[0022] In a particularly preferred improvement of the drill bit according to the invention, the control lever is configured such that it forms a closure element. This avoids the structural overhead associated with additional closure elements.

[0023] When at least a portion of the cutting tool is configured as a roller cutting tool, the drill bit according to the invention is particularly suitable for downward drilling, even on rock substrates.

[0024] If the drill bit's base and at least one extender arm are configured such that the effective borehole diameter can be extended within the range of 5000 mm and 8000 mm, then the drill bit according to the invention is particularly suitable for introducing pile foundations for wind power equipment in offshore areas. In one embodiment of the drill bit according to the invention, the effective borehole diameter can be, for example, 5150 mm in the retracted position of at least one extender arm, 6800 mm in a first extended position with an increased first value, and 7400 mm in a second extended position with an increased second value.

[0025] The present invention also relates to a drilling system comprising a rotating device, a support rod, and a drill bit according to the present invention coupled to the support rod. Attached Figure Description

[0026] An embodiment of the drill bit according to the invention is shown schematically in the accompanying drawings. The drawings show:

[0027] Figure 1 A side view of an embodiment of a drill bit according to the invention is shown in the region of a small-diameter column, the drill bit having an extended arm in a retracted position;

[0028] Figure 2 Showing according to Figure 1 Bottom view of this embodiment of a drill bit having an extended arm in the retracted position;

[0029] Figure 3 The same embodiment of the drill bit according to the invention is shown in the region of the larger diameter of the column, corresponding to... Figure 1 The view shows the drill bit having an extended arm in a first deployed position;

[0030] Figure 4 The same embodiment of the drill bit according to the invention is shown in a position corresponding to the lower end of the column. Figure 3 A view showing the drill bit having an extended arm in a second deployed position; and

[0031] Figure 5 A bottom view of the same embodiment of the drill bit according to the invention is shown, wherein the horizontally extending extension arm is in a first deployed position and the vertically extending extension arm is in a second deployed position. Detailed Implementation

[0032] An embodiment of the drill bit according to the invention (hereinafter referred to as "drill bit 100"), which is generally indicated by 100 in the accompanying drawings, is shown during operation and in... Figure 1 The support rod 1 shown is coupled and can be placed in rotation about the rotation axis S by means of a rotating device not shown in the figures. The drill bit 100 is therefore able to rotate about the rotation axis S during operation.

[0033] The drill bit has a base 2, which includes an end side 4 equipped with a plurality of first cutting tools 3.

[0034] Furthermore, the drill bit 100 has extension arms 5, which are offset by 90° about their central plane along the direction of rotation. Each extension arm 5 is coupled to the base 2 by means of a bolt 6, which defines a pivot axis W about which the corresponding extension arm can pivot. The pivot axis W is oriented perpendicular to the rotation axis S.

[0035] Each extension arm 5 includes an operating side 8 equipped with multiple second cutting tools 7.

[0036] Each extension arm 5 can... Figure 1 and 2 The retracted position, the first extended position, and the second extended position shown pivot about the pivot axis W, in which each active side 8 and the end side 4 are at least approximately located in a plane E and the drill bit has an effective borehole diameter D0 (see...). Figure 1 In the first deployment position, the effective borehole diameter D1 is increased by a first value B1 (see...). Figure 3 In the second deployment position, the effective borehole diameter D2 is increased by a second value B2 (see...). Figure 4 ).

[0037] As in Figure 3 and Figure 4 As can be seen, the functional side 8 of the extendable arm 5 is only in the first deployed position. Figure 3 ) in the second unfolded position ( Figure 4 The direction of the axis of rotation S extends from the end side 4 of the base 2 with at least approximately no step offset.

[0038] With the extension arm 5 in the first and second extended positions, the working side 8 has an angle α between 20° and 45°, preferably about 37°, relative to the end side 4 of the base 2. In this way, drill cuttings removed by the second cutting tool 7 of the extension arm 5 fall along the borehole center direction under gravity and are then, for example, more simply, drawn out by suction via the suction port 9 located in the end side 4 of the base 2.

[0039] In order to enable the extender arm 5 to pivot between the retracted position and the first and second extended positions, each extender arm 5 is provided with a hydraulic cylinder 10. Each hydraulic cylinder is hinged to the base 2 at a first end 11 and to a control lever 13 at a second end 12.

[0040] Each operating lever 13 is hinged to the region of the extension arm 5 facing the rotation axis S via a first operating lever end 14. The second operating lever end 15 of the operating lever 13 is movably supported on the base 2 in a guide portion 16 parallel to the rotation axis S.

[0041] For example, through comparison Figure 1 ,3 As can be seen from Figure 4, the change in the length of the hydraulic cylinder causes the extended arm 5 to pivot about the pivot axis W by means of this device.

[0042] The operating lever 13 is configured such that it at least substantially closes the gap surface created between the end side 4 of the base 2 and the working side 8 of the extension arm 5 in the first and second deployed positions. Therefore, the operating lever also serves to form a sealing element 17 that prevents drill cuttings from entering the base 2 and prevents the extension arm 5 from jamming as a result.

[0043] List of reference numerals in the attached diagram:

[0044] 100 drill bits

[0045] 1. Bearing rod

[0046] 2. Matrix

[0047] 3 Cutting tools

[0048] 4 end sides

[0049] 5 Extending Arms

[0050] 6 bolts

[0051] 7 Cutting tools

[0052] 8. Action side

[0053] 9. Suction port

[0054] 10 Hydraulic cylinders

[0055] 11 First end

[0056] 12 Second end

[0057] 13 Control levers

[0058] 14 First end

[0059] 15 Second end

[0060] 16 Guiding Section

[0061] 17. Enclosed elements

[0062] B1 and B2 values

[0063] Diameters D0, D1, and D2

[0064] E plane

[0065] S Rotation axis

[0066] W pivot axis

[0067] A angle

Claims

1. A drill bit (100) that is rotatable about a rotation axis (S) during operation and whose effective drilling diameter (D0, D1, D2) is expandable, the drill bit having: The substrate (2) includes an end side (4) equipped with at least one first cutting tool (3); And at least one extension arm (5) that is pivotable to the base (2) about a pivot axis (W) and pivotable between a retracted position and a first extended position that increases the effective borehole diameter by a first amount (B1), wherein the at least one extension arm (5) includes an active side (8) equipped with at least one second cutting tool (7). characterized in that In the retracted position of the at least one extended arm (5), the active side (8) and the end side (4) of the base (2) are at least approximately located on the same plane (E). Furthermore, in the first deployed position of the at least one extended arm (5), the active side (8) extends from the end side (4) of the base (2) in a manner that is at least approximately stepless in the direction of the rotation axis (S). The at least one extension arm (5) is pivotable to a second deployed position, which increases the effective borehole diameter by a second amount (B2).

2. The drill bit according to claim 1, characterized in that, In the first deployed position and / or the second deployed position, the working side (8) of the at least one extended arm (5) is inclined at an angle (α) of 20° to 45° relative to the end side (4) of the base (2) from the end side (4) toward the base (2).

3. The drill bit according to claim 1 or 2, characterized in that, A closing element (17) is provided, which at least substantially closes the gap surface generated between the end side (4) and the working side (8) in the first or second deployment position of the at least one extension arm (5).

4. The drill bit according to claim 3, characterized in that, The at least one extension arm (5) has a side facing the axis of rotation (S), in the region of this side, a first operating lever end (14) of the operating lever (13) is hinged to the at least one extension arm (5) in a manner that allows it to pivot about an axis that is substantially parallel to the axis of rotation, and a second operating lever end (15) of the operating lever (13) is movably hinged to the base (2) along the guide portion (16).

5. The drill bit according to claim 4, characterized in that, A linear motor is provided, which is hinged to the base (2) by means of a first end (11) and to the operating lever (13) by means of a second end (12).

6. The drill bit according to claim 4, characterized in that, The operating lever (13) is sized such that it forms the closing element (17).

7. The drill bit according to claim 1 or 2, characterized in that, At least a portion of the first cutting tool (3) and the second cutting tool (7) are configured as roller turning tools.

8. The drill bit according to claim 1 or 2, characterized in that, The effective borehole diameter can be increased from 5000mm to 8000mm.

9. The drill bit according to claim 5, characterized in that, The linear motor includes a pneumatic cylinder.

10. The drill bit according to claim 5, characterized in that, The linear motor includes a hydraulic cylinder (10).

11. A drilling system, the drilling system comprising a rotating device and a support rod (1), characterized in that, The drilling system further includes a drill bit (100) coupled to the support rod (1) according to any one of claims 1 to 10.

12. A method of using the drill bit according to claim 1, comprising: The drill bit (100) passes through the upper part of the pile foundation with the at least one arm (5) in the retracted position via the bearing rod (1); Deploy the at least one arm (5) to the first deployed position; A hole is drilled inside the pile foundation using the drill bit (100) in the first deployed position; Deploy the at least one arm (5) to the second deployed position; A hole is drilled below the pile foundation using the drill bit (100) in the second deployed position.

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