Drilling tool with drill bit including central pyramid structure

Abstract

The invention relates to a drilling tool, in particular a rock drilling tool, having a drill bit (130), which has a central pyramid structure (250) with at least four cutting edges (251, 252, 253, 254), and having at least two diametrically opposite main cutting elements (220, 240), each of which has a main cutting edge (221, 241); and at least two diametrically opposite secondary cutting elements (210, 230), each having a secondary cutting edge (211, 231), one secondary cutting element (210, 230) being arranged in each case between two adjacent primary cutting elements (220, 240) in the circumferential direction (198) of the drill bit (130), a cutting edge (251, 252, 253, 254) of at least four cutting edges (251, 252, 253, 254) of a central pyramid structure (250) is arranged in each case between each main cutting element (220, 240) of the at least two diametrically facing main cutting elements (220, 240) and each secondary cutting element (210, 230) of the at least two diametrically facing secondary cutting elements (210, 230) adjacent in each case in the circumferential direction (198) of the drill bit (130).

Description

Technical Field

[0001] The present invention relates to a drilling tool, particularly a rock drilling tool, having a drill bit having a central pyramid structure having at least four cutting edges; and having at least two diametrically opposed main cutting elements, each having a main cutting edge; and having at least two diametrically opposed secondary cutting elements, each having a secondary cutting edge, wherein a secondary cutting element is arranged between two adjacent main cutting elements in the circumferential direction of the drill bit. Background Technology

[0002] A drilling tool with a rock drilling tool configuration is known from the prior art. This drilling tool has a drill bit with at least two diametrically opposed main cutting elements, each having a main cutting edge, and at least two diametrically opposed secondary cutting elements, each having a secondary cutting edge. Here, a secondary cutting element is arranged between each pair of adjacent main cutting elements in the circumferential direction of the drill bit. Furthermore, the drill bit has a central pyramid structure with at least four cutting edges. Here, the cutting edges of the central pyramid structure coincide with the main and secondary cutting edges in the radial direction and form a common cutting edge with them. Summary of the Invention

[0003] This invention relates to a drilling tool, particularly a rock drilling tool, comprising a drill bit having a central pyramid structure with at least four cutting edges. The drill bit has at least two diametrically opposed primary cutting elements, each having a primary cutting edge; and at least two diametrically opposed secondary cutting elements, each having a secondary cutting edge. A secondary cutting element is arranged between each pair of adjacent primary cutting elements in the circumferential direction of the drill bit. One of the at least four cutting edges of the central pyramid structure is arranged between each of the at least two diametrically opposed primary cutting elements and each of the at least two diametrically opposed secondary cutting elements that are adjacent in the circumferential direction of the drill bit.

[0004] Therefore, the present invention enables a drilling tool in which the drilling speed can be simply and reliably increased by offsetting the cutting edge of the central pyramid structure relative to the main or secondary cutting edge, since the material to be processed is processed simultaneously at multiple locations.

[0005] Preferably, at least four cutting edges of the central pyramid structure are arranged relative to each other at associated angles in the circumferential direction of the drill bit.

[0006] Therefore, the proper arrangement of the cutting edges can be achieved in a simple way.

[0007] The angles assigned are preferably of the same size and are 90°.

[0008] Therefore, it is easy and simple to achieve a symmetrical arrangement of the cutting edges of the central pyramid structure.

[0009] Each of the at least four cutting edges of the central pyramid structure is preferably arranged at a predetermined angle relative to the adjacent main cutting edges in the circumferential direction of the drill bit in at least two main cutting elements that are diametrically opposed.

[0010] Therefore, it is possible to achieve a simple and application-specific arrangement of the cutting edge relative to the main cutting edge in the central pyramid structure.

[0011] The pre-given angle is preferably 30°, 45° or 60°.

[0012] Therefore, it is possible to easily match drilling tools with the impact modes associated with the corresponding handheld machine tools.

[0013] A suitable configuration is a drilling tool, particularly a rock drilling tool, comprising a drill bit having a rotation axis and at least two diametrically opposed primary cutting elements, each having a primary cutting edge; and at least two diametrically opposed secondary cutting elements, each having a secondary cutting edge, wherein a secondary cutting element is arranged between each pair of adjacent primary cutting elements in the circumferential direction of the drill bit. The primary cutting edges of the at least two diametrically opposed primary cutting elements each have a first maximum height extending from the base of the drill bit, and the secondary cutting edges of the at least two diametrically opposed secondary cutting elements each have a second maximum height extending from the base of the drill bit, wherein the first and second maximum heights are identical, at least within a predetermined manufacturing tolerance.

[0014] Therefore, the present invention enables a drilling tool in which jamming during drilling, particularly in drilling steel reinforcement elements, can be effectively prevented by ensuring that the main cutting element and the secondary cutting element have the same maximum height, at least within a pre-given manufacturing tolerance. Furthermore, this at least reduces the triggering of the slip clutch of the handheld tool used in the drilling process.

[0015] At least one secondary cutting edge of at least two diameter-facing secondary cutting elements and / or at least one primary cutting edge of at least two diameter-facing primary cutting elements preferably have a second maximum height on the outer periphery of the drill bit, and a reduced height between the axis of rotation and the outer periphery.

[0016] Therefore, drilling speeds can be increased, where at least one secondary cutting edge and / or primary cutting edge can penetrate the workpiece faster and deeper in the radially outer region. Furthermore, higher drilling speeds result in a larger total drilling stroke for the drilling tool.

[0017] Preferably, the main cutting edges of at least two diameter-facing main cutting elements and / or the secondary cutting edges of at least two diameter-facing secondary cutting elements have chamfers and / or fillets at their free ends, respectively.

[0018] Therefore, during the drilling process, especially during the drilling of reinforcing bars, it is possible to prevent the edges from getting stuck at the drill point in a simple way.

[0019] Preferably, a central pyramid structure with at least four cutting edges is provided, wherein one of the at least four cutting edges of the central pyramid is arranged between each of the main cutting elements that are directly opposite each other in at least two diameters and between each of the secondary cutting elements that are directly opposite each other in the circumferential direction of the drill bit.

[0020] Therefore, by staggering the cutting edge of the central pyramid structure relative to the main or secondary cutting edge, the corresponding drilling speed can be safely and reliably increased effectively, since the material to be processed can be processed simultaneously at multiple locations.

[0021] According to one embodiment, at least four cutting edges of the central pyramid structure are arranged relative to each other at 90° angles along the circumferential direction of the drill bit.

[0022] Therefore, it is easy and simple to achieve a symmetrical arrangement of the cutting edges of the central pyramid structure.

[0023] Preferably, each of the at least four cutting edges of the central pyramid structure is arranged at a predetermined angle to the main cutting edges of at least two diametrically opposed main cutting elements that are adjacent to each other in the circumferential direction of the drill bit, wherein the predetermined angle is 30°, 45° or 60°.

[0024] Preferably, the main cutting edges of at least two diameter-facing main cutting elements, the secondary cutting edges of at least two diameter-facing secondary cutting elements, and / or at least four cutting edges of the central pyramid structure are oriented along the radial direction of the drill bit.

[0025] Therefore, the cutting edge of the central pyramid structure can be appropriately arranged relative to the main cutting edge and the secondary cutting edge to achieve efficient drilling operation.

[0026] Preferably, the main cutting edges of at least two diameter-facing main cutting elements, the secondary cutting edges of at least two diameter-facing secondary cutting elements, and / or the at least four cutting edges of the central pyramid structure are at least segmentally constructed in a straight line, arc, convex curve, and / or concave curve.

[0027] Therefore, it is possible to achieve a suitable construction of the cutting edge, main cutting edge, and / or secondary cutting edge of the central pyramid structure in a simple manner.

[0028] According to one embodiment, at least one secondary cutting edge of at least two diameter-facing secondary cutting elements and / or at least one primary cutting edge of at least two diameter-facing primary cutting elements have a first height on the outer periphery of the drill bit, wherein the first height is reduced to a second height by a groove in the region facing the central pyramid structure.

[0029] Therefore, drilling speeds can be increased, thereby enabling at least one secondary cutting edge and / or primary cutting edge to penetrate the workpiece faster and deeper in the radially outer region. Furthermore, higher drilling speeds can result in a larger total drilling stroke for the drilling tool.

[0030] The drilling tool preferably has a drill rod having a fixing section for detachably fixing in the tool receiving section of a handheld machine tool and a spiral conveying section for removing drill chips accumulated during the machining process, wherein the drill rod is connected to the drill bit by a material locking connection.

[0031] Therefore, the drill bit and drill pipe can form a stable and robust connection.

[0032] The fixed section is preferably constructed as an SDS (Quick Clamping) bar.

[0033] This provides a common and widely used fixed section. Attached Figure Description

[0034] The invention is described in detail below with reference to the embodiments shown in the accompanying drawings. Herein lies: Figure 1 A top view of a drilling tool having a drill bit according to the invention. Figure 2 : Figure 1 A top view of the drill bit, which features a central pyramid structure. Figure 3 : Figure 1 and Figure 2 A three-dimensional view of the drill bit. Figure 4 : Figures 1 to 3 A top view of the drill bit, which features a central pyramid structure and is the first type of orientation. Figure 5 : Figures 1 to 4 A top view of the drill bit, which has an alternative orientation with a central pyramid structure. Figure 6 : Figures 1 to 5 A top view of the drill bit, which features an alternative orientation with a central pyramid structure. Figure 7 : Figures 1 to 6 A side view of the drill bit. Figure 8 : Figures 1 to 7 A side view of the drill bit, where, with Figure 7 In contrast, the drill bit is arranged in a twisted manner in the circumferential direction. Figure 9 : Figures 1 to 8 A three-dimensional view of the drill bit drilling into the reinforcing steel element.

[0035] In the accompanying drawings, elements with the same or similar functions are given the same reference numerals and are described in detail only once. Detailed Implementation

[0036] Figure 1 A generally cylindrical drilling tool 100 is shown. Typically, the drilling tool 100 is configured for reception in a receiving section of a machine tool, preferably a handheld machine tool, for drilling and / or impact processing. Here, the drilling tool 100 can be configured, for example, as a rock drilling tool for processing mineral materials such as rock, concrete, and / or reinforced concrete. The drilling tool 100 according to the invention can also be configured for processing other materials that appear meaningful to those skilled in the art, such as wood, plastic, or composite materials. The drilling tool 100 is preferably configured for performing rotational and / or translational working movements on the workpiece to be processed.

[0037] The drilling tool 100 extends axially along tool axis 199 in the diagram. Tool axis 199 here constitutes the axis of rotation of the drilling tool 100 and is referred to below as "axis of rotation 199". The drilling tool 100 preferably has at least one drill bit 130 and a drill rod 115 connected to the drill bit 130, the drill bit and drill rod preferably being integrally constructed or at least material-locked connected to each other. The drill rod 115 preferably has a fixing section 120 for detachably securing the drilling tool 100 to the tool receiving section of a handheld machine tool and a helical conveying section 110 for removing drill chips accumulated during machining. Alternatively, the drill rod 115 may be configured as a suction drill rod or the drilling tool 100 may be configured as a suction drilling tool, for example, having a suction opening in the drill rod 115.

[0038] The transport section 110 preferably has four transport channels 117 that meander spirally around the axis of rotation 199. These channels are configured to remove accumulated drill cuttings during machining in an axial direction away from the drill bit 130, for example, from the corresponding borehole. Alternatively or additionally, fewer than four (e.g., one, two, or three) or more than four (e.g., five, six, or more) transport channels 117 may be constructed.

[0039] The spiral conveying trough 117 is divided in the diagram by a spirally meandering ridge 118 around the axis of rotation 199 in the circumferential direction 198. The ridge 118 is preferably parallel to the conveying trough 117 and is accordingly spirally constructed.

[0040] The fixing section 120 is arranged on the side of the transport section 110 opposite to the drill bit 130 in the diagram. The fixing section 120 preferably has a plurality of radial grooves configured to enable form-locking and / or force-locking connection between the fixing section 120 of the drilling tool 100, especially the drilling tool 100, and the handheld tool.

[0041] According to one embodiment, the fixed section 120 of the drill pipe 115 is constructed as an SDS section. Here, the fixed section 120 can be constructed exactly the same as conventional and existing fixed sections (e.g., SDS, SDS-max, or SDS-plus fixed sections). Such SDS fixed sections are well known to those skilled in the art, and therefore a detailed description thereof is omitted.

[0042] Preferably, the axial end 111 of the drill rod 115, particularly the feed section 110, faces the base side 131 of the drill bit 130. According to one embodiment, the drill rod 115 is connected to the drill bit 130 by a material-locking connection, preferably integrally constructed with the drill bit. Here, the drill rod 115 and the drill bit 130 are connected by a material-locking connection, particularly with the aid of auxiliary materials or without auxiliary materials. Auxiliary materials can be used to connect the drill bit 130 and the drill rod 115, for example by fusion welding and / or brazing. Here, the auxiliary materials can be, for example, nickel, copper, cobalt, manganese, and / or tin. According to one embodiment, the drill bit 130 has a hard metal to withstand the highest wear load. The drill bit 130 is here particularly implemented as a fully hard metal head and restricts the axial extension of the drill rod 115 in the axial direction of the rotation axis 199. The drill rod 115 may here be made of steel.

[0043] Furthermore, the drill bit 130 preferably includes a plurality of cutting elements configured for removing, cutting, scraping, and / or crushing the workpiece to be processed. According to embodiments of the drill bit 130, the cutting elements can be categorized into main cutting elements (…). Figure 2 220, 240) and / or secondary cutting elements ( Figure 2(210 and 230 in the middle).

[0044] Figure 2 Show Figure 1 The drilling tool 100 includes a drill bit 130. The drill bit 130 preferably has at least three (four shown) cutting elements 210, 220, 230, and 240, each with an associated cutting edge 211, 221, 231, and 241. Furthermore, the drill bit 130 also includes a central pyramid structure 250, which preferably has at least three (four shown) cutting edges 251, 252, 253, and 254. Preferably, one cutting edge 251, 252, 253, or 254 of the central pyramid structure 250 is arranged between each of two adjacent cutting edges 211, 221, 231, or 241 in the circumferential direction.

[0045] It should be noted that the drill bit 130 may also have four or more cutting elements 210, 220, 230, 240, and / or the central pyramid structure 250 may also have four or more cutting edges 251, 252, 253, 254. Here, the number of cutting elements 210, 220, 230, 240 may differ from the number of cutting edges 251, 252, 253, 254 of the pyramid 250. Alternatively, the cutting elements 210, 220, 230, 240 and / or the central pyramid structure 250 may have different numbers of cutting edges 211, 221, 231, 241 or 251, 252, 253, 254. Therefore, a single cutting element 210, 220, 230, 240 may, for example, have two cutting edges.

[0046] According to one embodiment, two diameter-facing cutting elements 220 and 240 are configured as main cutting elements and are hereinafter referred to as "main cutting elements 220 and 240", and their associated cutting edges 221 and 241 are hereinafter referred to as "main cutting edges 221 and 241". Furthermore, two diameter-facing cutting elements 210 and 230 are configured as secondary cutting elements and are hereinafter referred to as "secondary cutting elements 210 and 230", and their associated cutting edges 211 and 231 are hereinafter referred to as "secondary cutting edges 211 and 231". Here, preferably, one secondary cutting element 210 or 230 is arranged between adjacent main cutting elements 220 and 240 in each of the two circumferential directions 198 of the drill bit 130. Preferably, a cutting edge 251, 252, 253, or 254 of a central pyramid structure 250 is arranged between the main cutting elements 220 and 240 and the secondary cutting elements 210 and 230 adjacent to the main cutting elements 220 and 240 in the circumferential direction 198 of the drill bit 130. In the figure, cutting edge 251 is arranged between the main cutting edge 241 and the secondary cutting edge 211 in the circumferential direction 198, cutting edge 252 is arranged between the secondary cutting edge 211 and the main cutting edge 221 in the circumferential direction 198, cutting edge 253 is arranged between the main cutting edge 221 and the secondary cutting edge 231 in the circumferential direction 198, and cutting edge 254 is arranged between the secondary cutting edge 231 and the main cutting edge 241 in the circumferential direction 198.

[0047] Preferably, the cutting edges 211, 221, 231, 241 and / or the cutting edges 251, 252, 253, 254 of the central pyramid structure 250 are oriented along the radial direction 299 of the drill bit 130. In particular, the main cutting edges 221, 241 of at least two diameter-facing main cutting elements 220, 240, the secondary cutting edges 211, 231 of at least two diameter-facing secondary cutting elements 210, 230 and / or the at least four cutting edges 251, 252, 253, 254 of the central pyramid structure 250 are oriented along the radial direction 299 of the drill bit 130.

[0048] According to one embodiment, at least one cutting edge 251, 252, 253, 254 of the central pyramid structure 250 may be constructed in a concave and / or convex curved shape. Furthermore, at least one pyramid facet of the central pyramid structure 250 may be constructed in a concave and / or convex curved shape.

[0049] Preferably, the main cutting edges 221, 241 of at least two diameter-facing main cutting elements 220, 240, the secondary cutting edges 211, 231 of at least two diameter-facing secondary cutting elements 210, 230, and / or the at least four cutting edges 251, 252, 253, 254 of the central pyramid structure 250 are constructed at least in sections with straight, arc, convex, and / or concave curves. Here, the cutting edges 211, 221, 231, 241 or 251, 252, 253, 254 may, for example, have a straight section that transitions into a convex curve section.

[0050] Figure 3 Show Figure 1 and Figure 2 The drill bit 130 has main cutting elements 220 and 240 and secondary cutting elements 210 and 230, and Figure 2 The central pyramid structure 250 is described. According to one embodiment, at least one primary cutting edge 221, 241 of at least two diameter-facing primary cutting elements 220, 240 and / or at least one secondary cutting edge 211, 231 of at least two diameter-facing secondary cutting elements 210, 230 has a chamfer 321, 331 and / or a fillet or rounding at its respective free ends 322, 332. Preferably, all primary cutting edges 221, 241 and / or all secondary cutting edges 211, 231 have chamfers 321, 331 and / or fillets, respectively. Alternatively, at least one cutting edge 251, 252, 253, 254 of the central pyramid structure 250 may have chamfers and / or fillets.

[0051] Figure 4 Show Figures 1 to 3 The drill bit 130 has main cutting elements 220 and 240 and secondary cutting elements 210 and 230, and Figure 2 and Figure 3 The central pyramid structure 250. Preferably, the cutting edges 251, 252, 253, 254 of the central pyramid structure 250 are arranged opposite each other in the circumferential direction 198 of the drill bit 130 with corresponding angles 411, 412, 413, 414, respectively. According to one embodiment, the corresponding angles 411, 412, 413, 414 are the same size. Preferably, the corresponding angles 411, 412, 413, 414 are 90°. Alternatively, the corresponding angles 411, 412, 413, 414 can be different. Furthermore, alternatively, each pair of opposite angles 411, 413, 412, 414 can be the same, wherein, for example, two angles are 80° and two angles are 100°.

[0052] According to one embodiment, in the illustration, the four cutting edges 251, 252, 253, 254 of the central pyramid structure 250 are positioned at a predetermined angle 401 relative to the adjacent main cutting edges 221, 241 of the main cutting elements 220, 240 in the circumferential direction 198 of the drill bit 130. Figure 5 The middle value is 501; Figure 6 The arrangement is as follows (501). For example, a predetermined angle 401, preferably 30°, is shown between the cutting edge 252 and the main cutting edge 221. Alternatively, the predetermined angle 401 may also be arranged between the cutting edges 251, 252, 253, 254 of the central pyramid structure 250 and the secondary cutting edges 211, 231 of the secondary cutting elements 210, 230 adjacent to each other in the circumferential direction 198 of the drill bit 130.

[0053] Figure 5 Show Figures 1 to 4 The drill bit 130, wherein a central pyramid structure 250 is arranged at a predetermined angle 501 relative to the primary cutting elements 220, 240 and / or the secondary cutting elements 210, 230. For example, the predetermined angle 501 between the cutting edge 252 of the central pyramid structure 250 and the primary cutting edge 221 of the primary cutting element 220 is shown. Preferably, with... Figure 4 In comparison, angle 501 is larger, preferably 45°.

[0054] Figure 6 Show Figures 1 to 5 The drill bit 130, wherein, for example, a predetermined angle 601 is shown between the cutting edge 252 and the main cutting edge 221. This angle 601 is preferably 60°. It should be noted that... Figure 4 Angle 401 in the middle Figure 5 Angle 501 and Figure 6 Angle 601 in the middle can also have any other angle value.

[0055] Figure 7 Show Figures 1 to 6A drill bit 130 has a base side 131 and main cutting elements 220, 240 and a secondary cutting element 230. The exemplary heights of the main and secondary cutting elements of the drill bit 130 are explained below. In the illustration, the main cutting elements 220, 240 have associated heights 712, 711, and the secondary cutting element 230 has an associated height 713. Here, heights 711, 712, and 713 are formed between the base side 131 of the drill bit 130 and the associated cutting edges 221, 241, 231 of the main cutting elements 220, 240 or the secondary cutting element 230, respectively. In the illustration, height 711 is formed between the base side 131 and the main cutting edge 241, height 712 is formed between the base side 131 and the main cutting edge 221, and height 713 is formed between the base side 131 and the secondary cutting edge 231.

[0056] According to one embodiment, at least one primary cutting element and / or at least one secondary cutting element have a constant or unchanging height. In the illustration, the heights 712 and 711 of the primary cutting elements 220 and 240 are constant or unchanging. Furthermore, these heights may be identical within a predetermined manufacturing tolerance range. For example, heights 711 and 712 are identical at least within a predetermined manufacturing tolerance range, as shown by the height line 710. In the illustration, line 710 is arranged parallel to the base side 131. Furthermore, heights 711, 712, and 713 preferably constitute the maximum height. Additionally, the primary cutting elements 220 and 240 and / or the secondary cutting element 230 (and...) Figures 1 to 6 210 in the middle can have a relatively large cutting edge length 721 oriented in the radial direction 299.

[0057] Figure 8 Show Figures 1 to 7 Drill bit 130, the drill bit in Figures 2 to 6 Circumferential direction 198 relative to Figure 7 The two auxiliary cutting elements 210 and 230 are arranged on the right and left sides in the diagram, while the main cutting element 220 is arranged in the middle. Figure 7 The secondary cutting element 230 has a height of 713. Figure 7 The main cutting element 220 has a height of 712. The secondary cutting element 210 has a height of 831 in the figure. Heights 713 and 831 are preferably formed on the secondary cutting elements 210 and 230 on the outer periphery 802 of the drill bit 130.

[0058] According to one embodiment, at least one secondary cutting edge 211, 231 and / or at least one primary cutting edge 221 (and...) Figure 7 241) has a corresponding maximum height on the outer periphery 802 of drill bit 130, wherein the maximum height corresponds to heights 831, 713, 712 (and Figure 7 (711 in the diagram). These maximum heights are reduced to a reduced height 833 in the region facing the central pyramid structure 250 via grooves 820. Thus, preferably, cutting edge lengths 811 are formed oriented in the radial direction 299. The cutting edge length 811 is greater than... Figure 7 The cutting edge length in the 721 is shorter.

[0059] In the diagram, the maximum heights 713 and 831 of the secondary cutting edges 211 and 231 are reduced. However, it should be noted that the main cutting edge 221 ( Figure 7 The maximum height of 712 (of 241) Figure 7 The 711 in the groove can also be reduced by the groove 820. Alternatively, at least one secondary cutting edge 211, 231 and / or at least one primary cutting edge 221 (and Figure 7 241) in its entire cutting edge length 811 (and / or Figure 7 The 721 in the middle is constructed in an arc shape. Here, at least one secondary cutting edge 211, 231 and / or at least one primary cutting edge 221 (and Figure 7 241) can be concave and / or convex curved.

[0060] Figure 9 Show Figures 1 to 8 The drill bit 130 performs an exemplary drilling process in the reinforcing bar element 910. In the diagram, the central pyramid structure 250 has here drilled a groove 920 in the reinforcing bar element 910. Due to the central pyramid structure 250 or the cutting edges 251, 252, 253, 254 associated with the central pyramid structure 250 (in... Figure 9 Only the cutting edge 253 is visible. These elements are arranged torsionally relative to the main cutting elements 220, 240 or the secondary cutting elements 210, 230, which can pass through the cutting edge during drilling. Figure 9 The main cutting edges (221, 241) are supported on the reinforcing bar element 910 or the formed hole. This prevents... Figure 1 The drilling tool 100 is recessed and / or inserted into the reinforcing bar element 910.

Claims

1. A drilling tool (100), particularly a rock drilling tool, comprising a drill bit (130) having: A central pyramid structure (250) having at least four cutting edges (251, 252, 253, 254), and At least two main cutting elements (220, 240) facing each other on diameter, each having a main cutting edge (221, 241), and At least two diametrically opposed secondary cutting elements (210, 230), each having a secondary cutting edge (211, 231). in, A secondary cutting element (210, 230) is arranged between two adjacent primary cutting elements (220, 240) in the circumferential direction (198) of the drill bit (130). The invention is characterized in that, between each of the main cutting elements (220, 240) that are directly opposite each of the at least two diameters, and between each of the secondary cutting elements (210, 230) that are directly opposite each of the at least two diameters, and between each of the secondary cutting elements (210, 230) that are adjacent to each other in the circumferential direction (198) of the drill bit (130), one of the four cutting edges (251, 252, 253, 254) of the central pyramid structure (250) is arranged.

2. The drilling tool according to claim 1, characterized in that, At least four cutting edges (251, 252, 253, 254) of the central pyramid structure (250) are arranged relative to each other at their respective angles (411, 412, 413, 414) in the circumferential direction (198) of the drill bit (130).

3. The drilling tool according to claim 2, characterized in that, The assigned angles (411, 412, 413, 414) are all the same size and are 90°.

4. The drilling tool according to any one of the preceding claims, characterized in that, Each of the at least four cutting edges (251, 252, 253, 254) of the central pyramid structure (250) is arranged at a predetermined angle (401, 501, 601) relative to the adjacent main cutting edges (221) of the at least two diametrically opposed main cutting elements (220, 240) in the circumferential direction (198) of the drill bit (130).

5. The drilling tool according to claim 4, characterized in that, The pre-given angles (401, 501, 601) are 30°, 45° or 60°.

6. The drilling tool according to any one of the preceding claims, characterized in that, The main cutting edges (221, 241) of the at least two diameter-aligned main cutting elements (220, 240), the secondary cutting edges (211, 231) of the at least two diameter-aligned secondary cutting elements (210, 230), and / or at least four cutting edges (251, 252, 253, 254) of the central pyramid structure (250) are oriented along the radial direction (299) of the drill bit (130).

7. The drilling tool according to any one of the preceding claims, characterized in that, The main cutting edges (221, 241) of the at least two diameter-facing main cutting elements (220, 240), the secondary cutting edges (211, 231) of the at least two diameter-facing secondary cutting elements (210, 230), and / or the at least four cutting edges (251, 252, 253, 254) of the central pyramid structure (250) are at least segmentally constructed in a straight line, arc, convex curve, and / or concave curve.

8. The drilling tool according to any one of the preceding claims, characterized in that, At least one of the at least two diameter-facing secondary cutting elements (210, 230) and / or at least one of the at least two diameter-facing primary cutting elements (220, 240) primary cutting elements (221, 241) primary cutting elements (220, 240 ...

9. A drilling tool according to any one of the preceding claims, comprising a drill rod (115) having a fixing section (120) for detachably fixing in a tool receiving section of a handheld machine tool and a helical conveying section (110) for removing drill chips accumulated during machining, wherein, The drill rod (115) is connected to the drill bit (130) by a material locking connection.

10. The drilling tool according to claim 9, characterized in that, The fixed section (120) is constructed as an SDS rod.

Images