Drilling tool

Abstract

A drilling tool is configured to perform drilling and/or percussive work on materials such as stone, concrete and/or reinforced concrete. The drilling tool has a fastening region and a working region. The working region has a working body and at least one cutting element projecting axially and/or radially in relation to the working body. The at least one cutting element has at least one first cutting edge and at least one second cutting edge. The at least one second cutting edge is configured to serve as a replacement cutting edge and/or as an auxiliary cutting edge, and the at least one second cutting edge is set back, at least partly, in relation to the at least one first cutting edge of the drilling tool, axially along a longitudinal axis of the drilling tool, in a direction towards the fastening region.

Claims

1. A drilling tool for performing drilling and/or percussive work on materials, the drilling tool comprising: a fastening region; and a working region, the working region having a working body and at least one cutting element projecting axially and/or radially in relation to the working body, the at least one cutting element having a leading face portion with respect to a direction of rotation about a longitudinal axis of the drilling tool and a trailing face portion opposite to the leading face, the at least one cutting element having between the leading face portion and the trailing face portion at least one first cutting edge and at least one second cutting edge, wherein the at least one second cutting edge is configured to serve as a replacement cutting edge and/or as an auxiliary cutting edge, and wherein the at least one second cutting edge is set back in relation to the at least one first cutting edge of the drilling tool, axially along the longitudinal axis of the drilling tool, in a direction towards the fastening region, and wherein up to 70% of a maximum extent of the at least one second cutting edge is disposed parallel to the at least one first cutting edge.

2. The drilling tool according to claim 1, wherein: during operation of the drilling tool, the at least one first cutting edge, in the case of a rotation about the longitudinal axis, defines a first envelope, and the at least one second cutting edge, in the case of a rotation about the longitudinal axis, defines a second envelope, and the second envelope is set back in relation to the first envelope, axially along the longitudinal axis of the drilling tool, in the direction towards the fastening region of the drilling tool.

3. The drilling tool according to claim 2, wherein the second envelope is set back at least partly in relation to the first envelope.

4. The drilling tool according to claim 1, wherein an indentation is provided in the at least one cutting element between the at least one first cutting edge and the at least one second cutting edge.

5. The drilling tool according to claim 4, wherein the indentation is an axial indentation.

6. The drilling tool according to claim 1, wherein the at least one second cutting edge is set back in relation to the at least one first cutting edge contrary to a direction of rotation of the drilling tool.

7. The drilling tool according to claim 1, wherein the at least one first cutting edge is set back in relation to the at least one second cutting edge contrary to a direction of rotation of the drilling tool.

8. The drilling tool according to claim 1, wherein the at least one second cutting edge is adjacent to a circumferential region of the drilling tool.

9. The drilling tool according to claim 1, wherein a maximum radial extent of the at least one second cutting edge extends no greater than 90% in relation to a maximum radial extent of the at least one first cutting edge.

10. The drilling tool according to claim 9, wherein the maximum radial extent of the at least one second cutting edge extends by up to 50% in relation to the maximum radial extent of the at least one first cutting edge.

11. The drilling tool according to claim 1, wherein a maximum axial extent of the at least one second cutting edge extends no greater than 90% in relation to a maximum radial extent of the at least one first cutting edge.

12. The drilling tool according to claim 11, wherein the maximum axial extent of the at least one second cutting edge extends by up to 50% in relation to a maximum radial extent of the at least one first cutting edge.

13. The drilling tool according to claim 1, further comprising: a main cutting element, wherein the at least one cutting element is a secondary cutting element.

14. The drilling tool according to claim 1, wherein the drilling tool is configured to perform drilling and/or percussive work on materials such as stone, concrete and/or reinforced concrete.

15. The drilling tool according to claim 1, wherein the at least one cutting element is a cutting plate cutting element.

16. The drilling tool according to claim 1, wherein the at least one second cutting edge is set back at least partly in relation to the at least one first cutting edge.

17. The drilling tool according to claim 1, wherein the maximum extent is one of an axial maximum extent and a radial maximum extent.

18. The drilling tool of claim 1, the at least one cutting element further comprising: a rake face extending axially from the leading face portion toward the at least one first cutting edge; and a flank extending axially from the trailing face portion toward the at least one first cutting edge, wherein the at least one second cutting edge is defined in part by the rake face or the flank, and wherein neither the first cutting edge nor the second cutting edge extend through a longitudinal axis of the drilling tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages are disclosed by the following description of the drawing. Exemplary embodiments of the disclosure are represented in the drawing. The drawing and the description contain numerous features in combination. Persons skilled in the art will expediently also consider these features individually and combine them to form appropriate further combinations.

(2) There are shown in this case

(3) FIG. 1 a perspective view of a hand-held power tool, with a drilling tool,

(4) FIG. 2 a view of a first embodiment of a drilling tool according to the disclosure,

(5) FIG. 3 a perspective view of a second embodiment of a drilling tool,

(6) FIG. 4 a perspective view of a cutting element of a third embodiment of the drilling tool,

(7) FIG. 5 a perspective view of a fourth embodiment of a drilling tool, and

(8) FIG. 6 a perspective view of a cutting element of the fourth embodiment of the drilling tool.

(9) In the following figures, parts that are the same are denoted by the same references.

DETAILED DESCRIPTION

(10) The following figures each relate to a drilling tool for performing drilling and/or percussive work on, in particular mineral, materials such as, for example, stone, concrete and/or reinforced concrete. The drilling tool is, in particular, for fastening in a holding device of a power tool, preferably a hand-held power tool, having a rotatory and/or translatory working motion on a workpiece on which work is to be performed. In this case, a translatory advance into the workpiece is made in that the operator of the hand-held power tool applies a force to the hand-held power tool, in particular to a housing of the hand-held power tool. The drilling tool according to the disclosure may also be provided for performing work on other materials, considered appropriate by persons skilled in the art, such as wood, plastic or a composite.

(11) FIG. 1 shows a perspective view of a hand-held power tool 101, having a drilling tool 1 clamped in the holding device 105. The hand-held power tool 101 has a hand-held power-tool housing 103, having at least one grip region 109, to be gripped by at least one hand of a user. The holding device 105 may have, for example, three clamping jaws 107, of which only two clamping jaws 107 are shown. The clamping jaws 107 clamp the drilling tool 1 radially and/or axially in the holding device 105.

(12) FIG. 2 shows a first embodiment of a drilling tool 1, having a fastening region 3 for fastening in a holding device 105 of a hand-held power tool 101, and having a working region 5 for performing work on a workpiece. The drilling tool 1 is realized, at least substantially, in the form of a cylinder. The fastening region 3 has a circular cross-sectional area, at least in portions. Alternatively or additionally, the cross-sectional area may have a polygon-type cross section, at least in portions. The fastening region 3 extends axially from a clamping end of the drilling tool 1 as far as the working region 5, and is adjacent to the working region 5. In this case, the maximum radial extent, in particular a maximum diameter, of the drilling tool 1 increases in a transitional region between the fastening region 3 and the working region 5.

(13) The fastening region 3 has positive-engagement means 15, realized as depressions, which may be provided to effect an improved, in particular positive-engagement, connection to the holding device 105 of the hand-held power tool 101. Alternatively or additionally, positive-engagement means 15 may be realized as protuberances. In an alternative embodiment, the fastening region 3 of the drilling tool 1 may also be realized without positive-engagement means 15. In particular, the fastening region 3 may be designed so as to correspond to an SDS fastening region.

(14) The working region 5 adjoining the fastening region 3 comprises a main cutting element 7, in particular realized as a tip cutter, and two mutually opposite secondary cutting elements 9, in particular realized as tip cutters. The main cutting element 7 and the secondary cutting elements 9 are realized in the working body 6, at the end. The main cutting element 7 and the secondary cutting elements 9 in this case are connected, in particular in a materially bonded manner, preferably welded, to a working body 6 of the drilling tool 1. The secondary cutting elements 9 are spaced apart radially from the main cutting element 7.

(15) The main cutting element 7 is preferably made of hard metal.

(16) The working region 5 additionally comprises two grooves 13, extending helically around a longitudinal axis a of the drilling tool 1, which are realized in the working body 6 of the drilling tool 1. The two grooves 13 are parallel to each other. The two grooves 13 extend in an axially adjacent manner from a fastening region 3 of the drilling tool 1 and terminate adjacent to an end region 51 of the working region 5. An, in particular minimum, radial extent of the two grooves 13 is realized so as to be constant along an axial extent of the two grooves 13. Alternatively, an, in particular minimum, radial extent of the two grooves 13 may decrease, at least partly continuously and/or at least partly discontinuously, in the direction of the end region 51. The two grooves 13 are separated in the circumferential direction by webs 11. The webs 11 are therefore also parallel to the grooves 13 and, accordingly, are helical in form.

(17) FIG. 3 shows a view of a second embodiment of the drilling tool 1. In this case, in this embodiment, the main cutting element 7, realized as a tip cutter, is realized in the working body 6, and the secondary cutting elements 9 are realized as a single piece with the working body 6, or integrally therefrom. A cross-sectional area of the end region 51 in this case is at least substantially of a polygon type, in particular substantially quadrilateral. At the end face the working region 5 has an elevation 17, in particular realized as a protuberance, which extends axially and radially in relation to the longitudinal axis a. The elevation 17 extends, at least substantially, in the form of a circle around the longitudinal axis a, in particular in a radially inner region of an end face of the drilling tool 1.

(18) The two secondary cutting elements 9 extend in a radial direction out of the end region 51, and project in relation to the end region 51. The secondary cutting elements 9 each have a cutting edge 19, 21 for performing cutting work on the workpiece.

(19) The main cutting element 7 has two first cutting edges 19, and respectively second cutting edges 21 set back from the two first cutting edges 19 axially along a longitudinal axis a in the direction towards the fastening region. The second cutting edge 21 is disposed parallel to the first cutting edge 19.

(20) The first cutting edges 19 are realized symmetrically in relation to the longitudinal axis a of the drilling tool 1 and extend, starting from a drill-bit tip 31, to a circumferential region 33, in particular a circumferential surface, of the main cutting element 7. The second cutting edges 21 are likewise realized symmetrically in relation to the longitudinal axis a of the drilling tool 1. The second cutting edge 21 is in each case set back in relation to the first cutting edge 19, contrary to the direction of rotation w of the drilling tool 1. The second cutting edges 21 are each provided in a flank region of the first cutting edges 19. In an alternative embodiment, the second cutting edge 21 in each case is set back in relation to the first cutting edge 19, in the direction of rotation w of the drilling tool 1. In an alternative embodiment, the second cutting edges 21 may each provided in a rake face region of the first cutting edges 19.

(21) A projection of the second cutting edge 21 on a plane formed orthogonally in relation to the longitudinal axis a of the drilling tool 1 is disposed parallel to the first cutting edge 19. In an alternative embodiment, a projection of the second cutting edge 21 may extend at an angle in relation to the first cutting edge 19 on a plane formed orthogonally in relation to the longitudinal axis a of the drilling tool 1.

(22) The at least one second cutting edge 21 extends in a radial direction by up to 95% in relation to the at least one first cutting edge 19. In this case, a maximum axial extent of the at least one second cutting edge 21 extends by up to 95% in relation to the maximum axial extent of the at least one first cutting edge 19.

(23) Provided between the first cutting edge 19 and the second cutting edge 21 there is a respective indentation 27 in the main cutting element 7.

(24) The indentation 27 is realized in the axial direction, in particular in the form of a wedge, in the main cutting element 7. In this embodiment, the indentation 27 is delimited by the second cutting edge 21. The indentation 27 has at least two faces 55, 59, disposed transversely in relation to each other. The two faces 55, 59 form an edge 27, which is at least partly set back in relation to the first cutting edge 19 and the second cutting edge 21, contrary to the direction of advance. In particular, the edge 27 adjoins the second cutting edge 21 in a radially inner region of the end region 51, or converges with the second cutting edge 21. The two faces 55, 59 are each disposed at a distance from the first cutting edge 19. The indentation 27 preferably extends in a radially outer region of the main cutting element 7.

(25) From a longitudinal axis a of the drilling tool 1, the first cutting edge 19 extends in the radial and the axial direction, and delimits a radial extent of the main cutting element 7 of the drilling tool 1. The first cutting edge 19 is realized by a rake face 53 and by a flank 61 that adjoins the first rake face 53. The flank 61 and, in particular, the indentation 27 in this case separate the first cutting edge 19 from the second cutting edge 21.

(26) The second cutting edge 21 is realized by a contrary to the direction of rotation w by the flank 61 and the face 55, formed as a rake face, that adjoins the flank 61.

(27) The rake face 53 is realized as a rake face of the first cutting edge 19. The The flank 61 is realized as a flank of the first cutting edge 19. The face 59 is realized as a second flank of the first cutting edge 19 that adjoins the flank 61. The face 55 is realized as a rake face of the second cutting edge 21.

(28) In this embodiment, the flank 61 surrounds the indentation 27, such that the flank 61 also forms a flank of the second cutting edge 21.

(29) A further embodiment of the main cutting element 7 shown in FIG. 4. Unlike the embodiment according to FIG. 3, the indentation 27 is delimited by the first cutting edge 19 and the second cutting edge 21. In particular, the first cutting edge 19 is realized by the rake face 53 and the face 59 adjoining the rake face 53 and, in particular at least partly, the flank 61. The face 59 and the flank 61 in this case are realized as flanks of the first cutting edge 19.

(30) The second cutting edge 21 is realized by a face 55 adjoining the face 59 contrary to the direction of rotation w and by the flank 61. The face 59 and the face 55 in this case realize the indentation 27.

(31) A fourth embodiment of the drilling tool 1 according to the disclosure is shown in FIG. 5 and FIG. 6, a cutting element 8 being realized such that it is at least substantially similar to the cutting elements 7, 9 of the first embodiment. The drilling tool 1 in this case is realized as a hollow drilling tool 1. The working body 6 in this case is realized, at least substantially, as a hollow cylinder. The working body 6 has a cylindrical inner region 83, in particular a cylindrically realized inner surface, and an outer region 85 disposed on the outside in relation to the inner region 83. The outer region 85 additionally has at least one groove 13, and at least one web 11 delimiting the groove 13. The groove 13 and the web 11 are at least substantially parallel to each other. The groove is helical in form, and extends around the hollow drilling tool 1, or the outer region 85 of the hollow drilling tool 1, around a longitudinal axis a.

(32) The cutting elements 8 in this case are realized at the end, in a recess in an end region 87 of the hollow drilling tool 1, such that a front face 93 and a back face 87 of the cutting element 8 are connected to the working body 6 of the drilling tool 1 by positive engagement and/or in a materially bonded manner The cutting elements 8 extend transversely, in particular orthogonally, in relation to the inner region 83, in particular the inner faces, and the outer region 85, in particular the outer faces, of the working body 6. The cutting elements 8 have, on both sides, lateral faces 91 that delimit the cutting elements 8 in the radial direction. The lateral face 91b that faces towards the outer region 85 projects in relation to the outer face 85. The lateral face 91a of the cutting element 8 that faces towards the inner region 83 likewise projects in relation to the inner face 87. In an alternative embodiment, only one or no lateral faces 91 may also project in relation to the inner region 83, or the inner faces, and/or the outer region 85, or the outer faces.

(33) The cutting elements 8 are realized such that they are substantially similar to the main cutting element 7, and likewise, as described, for example, in the second and/or third embodiment, have a first cutting edge 19 and a second cutting edge 21 set back in relation to the first cutting edge 19, contrary to the direction of advance and/or contrary to the direction of rotation. An indentation 27 is likewise provided between the first cutting edge 19 and the second cutting edge 21. The first cutting edge 19 and the second cutting edge 21 are disposed parallel to each other.

(34) The first cutting edge 19 forms a first envelope, and the second cutting edge 21 forms a second envelope, such that the second envelope is set back axially in relation to the first envelope, contrary to the direction of advance of the hollow drilling tool 1. Preferably, a plurality of first cutting edges 19 of the cutting elements 8 are located on the first envelope. In particular, a plurality of second cutting edges 21 of the cutting elements 8 are located on a second envelope. The first envelope is disposed parallel to the second envelope.