Drilling device

Abstract

A drilling device includes a drill basic body and a conveying helix which runs helically around the drill basic body. The conveying helix is subdivided into a plurality of conveying helix segments that are disposed next to one another. The conveying helix segments may be disposed loosely next to one another.

Claims

1. A drilling device, comprising: a drill basic body; and a conveying helix, wherein the conveying helix runs helically around the drill basic body and wherein the conveying helix is subdivided into a plurality of conveying helix segments disposed next to one another; wherein the plurality of conveying helix segments are each comprised of a plastics material; wherein the plurality of conveying helix segments each have a respective metal insert part disposed on a radially outermost circumferential edge of a respective conveying helix portion of the respective conveying helix segment; and wherein the respective metal insert part is at least partially disposed in the plastics material of the respective conveying helix segment.

2. The drilling device as claimed in claim 1, wherein the plurality of conveying helix segments are disposed next to one another in a connection-free manner.

3. The drilling device as claimed in claim 1, wherein the plurality of conveying helix segments are connected to the drill basic body in a form-fitting manner.

4. The drilling device as claimed in claim 3, wherein the drill basic body has an engagement portion and the plurality of conveying helix segments each have a respective mating engagement portion which engages in the engagement portion in the form-fitting manner.

5. The drilling device as claimed in claim 1, wherein each of the plurality of conveying helix segments has a respective base portion through which the drill basic body is guided and wherein the respective conveying helix portion runs helically around the respective base portion.

6. The drilling device as claimed in claim 5, wherein the respective base portions are hollow and cylindrical and have two end sides that are oriented perpendicularly to an axis of symmetry of the drilling device.

7. The drilling device as claimed in claim 5, wherein the respective base portions and the respective conveying helix portions are formed in one piece.

8. The drilling device as claimed in claim 5, wherein a pitch of the conveying helix is dimensioned such that the respective conveying helix portion runs once helically around the respective base portion.

9. The drilling device as claimed in claim 1, wherein the respective metal insert parts of adjacent ones of the plurality of conveying helix segments do not contact one another.

10. The drilling device as claimed in claim 1 further comprising an elastomer ring, wherein the elastomer ring arrests the plurality of conveying helix segments on the drill basic body.

11. The drilling device as claimed in claim 10, wherein the plurality of conveying helix segments are disposed between the elastomer ring and a drilling head of the drill basic body.

12. The drilling device as claimed in claim 10, wherein the elastomer ring bears against a shoulder that runs around the drill basic body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic view of one embodiment of a drilling device;

(2) FIG. 2 shows a schematic view of one embodiment of a drill basic body for the drilling device according to FIG. 1;

(3) FIG. 3 shows a schematic sectional view of the drill basic body along the section line III-III of FIG. 2;

(4) FIG. 4 shows a schematic sectional view of one embodiment of a conveying helix segment for the drilling device along the section line IV-IV of FIG. 1; and

(5) FIG. 5 shows a schematic view of a further embodiment of a drilling device.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) Identical or functionally identical elements are indicated by the same reference signs in the Figures, unless stated otherwise.

(7) FIG. 1 shows a schematic view of one embodiment of a drilling device 1. The drilling device 1 is a core drill, masonry drill or hammer drill or can be referred to as such. The drilling device 1 comprises a drill basic body 2 shown in FIGS. 2 and 3. The drill basic body 2 can also be referred to as a drill shaft or drill blank. The drill basic body 2 is manufactured from metal, for example from a steel alloy.

(8) The drill basic body 2 comprises a drilling head 3 with cutting bodies 4. The cutting bodies 4 can comprise, for example, a hard metal or a ceramic material. A material to be machined, for example masonry or concrete, can be abrasively removed by means of the cutting bodies 4. The cutting bodies 4 can, for example, be brazed to the drilling head 3. Furthermore, the drilling head 3 comprises a center drill 5 which projects beyond the latter in a longitudinal direction L2 of the drill basic body 2. The center drill 5 can also comprise a hard metal or a ceramic material.

(9) The drill basic body 2 further comprises a shank 6, by means of which the drilling device 1 can be releasably connected to a handheld power tool. The handheld power tool can be, for example, a rotary hammer, a chisel hammer, a core drill or the like. The shank 6 comprises a plurality of driving slots 7 which serve for a form-fitting engagement of locking elements of the handheld power tool. A form-fitting connection occurs as a result of at least two connection partners, in this case the driving slots 7 and the locking elements, engaging in one another or behind one another.

(10) A shaft 8 of the drill basic body 2 extends in the longitudinal direction L2 between the drilling head 3 and the shank 6. The shaft 8 comprises an engagement portion 9. The engagement portion 9 can be an outer polygon, in particular an outer hexagon (FIG. 3). The engagement portion 9 is connected to the drilling head 3 by means of a transition region 10 which is preferably circular in cross section.

(11) Between the shank 6 and the engagement portion 9, there is provided an engagement region 11 which is preferably circular in cross section and which is delimited from the shank 6 by a peripheral shoulder 12. The engagement portion 9, the transition region 10 and the engagement region 11 are part of the shaft 8. The drill basic body 2 is designed to be substantially rotationally symmetrical to a center axis or axis of symmetry M. The longitudinal direction L2 runs parallel to the axis of symmetry M or corresponds thereto.

(12) Returning now to FIG. 1, the drilling device 1 comprises, in addition to the drill basic body 2, a conveying helix 13 which runs spirally, helically or in the form of a screw around the drill basic body 2. The conveying helix 13 is suitable, in a longitudinal direction L1 of the drilling device 1, to convey drillings, for example masonry dust, away from the drilling head 3 in the direction of the shank 6 of the drill basic body 2. The longitudinal direction L1 here corresponds to the longitudinal direction L2. The longitudinal directions L1, L2 are oriented here from bottom up in the orientation of FIGS. 1 and 2, that is to say from the drilling head 3 in the direction of the shank 6. The drilling device 1 is also designed to be substantially rotationally symmetrical to the axis of symmetry M. The conveying helix 13 can also be referred to as a conveying spiral or conveying screw.

(13) The conveying helix 13 is assigned an envelope E. The envelope E is cylindrical with a circular base. The envelope E is defined by an outer surface or outer edge 14 of the conveying helix 13 that is arranged spaced apart from the axis of symmetry M in a radial direction R and runs spirally around the axis of symmetry M. Here, the radial direction R is oriented perpendicularly to and away from the axis of symmetry M.

(14) The conveying helix 13 is subdivided into a plurality of conveying helix segments 15 to 21 arranged next to one another. The number of conveying helix segments 15 to 21 is arbitrary. In particular, however, at least two such conveying helix segments 15 to 21 are provided. FIG. 1 shows seven conveying helix segments 15 to 21 which are threaded onto the shaft 8 of the drill basic body 2. The conveying helix segments 15 to 21 are arranged loosely next to one another. That is to say that the conveying helix segments 15 to 21 are not connected to one another and take the form of separate components. This allows the replacement of individual conveying helix segments 15 to 21. As viewed in the longitudinal direction L1, the conveying helix segments 15 to 21 can have different lengths or equal lengths.

(15) The conveying helix, and in particular the individual conveying helix segments 15 to 21, is/are preferably manufactured from a plastics material. For example, the conveying helix segments 15 to 21 can be manufactured from polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE) or any other suitable plastics material. The plastics material is in particular a thermoplastic. For example, the conveying helix segments 15 to 21 can be cost-effective plastic injection-molded components. The conveying helix 13 can also be referred to as a plastic conveying helix.

(16) Each conveying helix segment 15 to 21 has, as shown by way of the conveying helix segment 21, a tubular base portion 22, which is plugged onto the drill basic body 2, in particular onto the engagement portion 9 of the shaft 8, and a conveying helix portion 23 which runs helically around the base portion 22. The conveying helix portions 23 of all the conveying helix segments 15 to 21 thus form the conveying helix 13, which runs around the drill basic body 2, with the outer edge 14. The base portions 22 are also part of the conveying helix 13.

(17) The base portion 22 and the conveying helix portion 23 of each conveying helix segment 15 to 21 are preferably formed in one piece, in particular in a materially integral manner. For example, the conveying helix segments 15 to 21 can, as mentioned above, be cost-effective plastic injection-molded components. The base portion 22 is hollow cylindrical and comprises two end faces or end sides 24, 25 which are oriented parallel to one another and perpendicularly to the axis of symmetry M. The end sides 24, 25 are annular and form a base of the hollow cylindrical geometry of the base portion 22.

(18) Here, a pitch, in particular a thread pitch, of the conveying helix 13 is selected in such a way that the respective conveying helix portion 23 of each conveying helix segment 15 to 21 runs once around the base portion 22 assigned to it. Alternatively, the pitch can also be selected in such a way that the conveying helix portion 23 runs a number of times, for example two or three times, around the base portion 22.

(19) As mentioned above, the conveying helix segments 15 to 21 are not connected to one another. However, the conveying helix segments 15 to 21 are connected to the drill basic body 2 in a form-fitting manner in such a way that the conveying helix segments 15 to 21 are secured to the drill basic body 2 in a rotationally fixed manner. As mentioned above, the drill basic body 2 has the engagement portion 9 which is shown in FIGS. 2 and 3. Accordingly, the base portions 22 of the conveying helix segments 15 to 21 have a mating engagement portion 26 (FIG. 4) corresponding to the engagement portion 9. The mating engagement portion 26 can, as shown in FIG. 4, be an inner polygon, in particular an inner hexagon, corresponding to the engagement portion 9.

(20) As shown in FIG. 1, the conveying helix segments 15 to 21 are threaded onto the drill basic body 2 in such a way that a first conveying helix segment 15 bears against the drilling head 3. The first conveying helix segment 15 is followed by a second to seventh conveying helix segment 16 to 21. The seventh conveying helix segment 21 for its part is secured with respect to the shoulder 12 of the drill basic body 2 by means of an elastomer ring 27. Here, the elastomer ring 27 engages in the engagement region 11. As viewed in the longitudinal direction L1, the conveying helix segments 15 to 21 are thus secured axially between the drilling head 3 and the elastomer ring 27. An antirotational safeguard of the conveying shaft segments 15 to 21 is ensured by means of the aforementioned engagement portion 9 and the corresponding mating engagement portion 26.

(21) It is possible after removal of the elastomer ring 27 for the conveying helix segments 15 to 21 to be removed from the drill basic body 2 in a simple manner. The elastomer ring 27 can always bear against the shoulder 12 or only when a force acting in the longitudinal direction L1 is applied to the conveying helix 13. In this case, a gap can be provided between the shoulder 12 and the elastomer ring 27.

(22) FIG. 5 shows a further embodiment of a drilling device 1. The drilling device 1 according to FIG. 5 differs from the drilling device 1 according to FIG. 1 substantially only in that the conveying helix portions 23 of the conveying helix segments 15 to 21 each have a metal strip or metal insert part 28 which points away from the respective base portion 22. The metal insert part 28 takes the form of a steel strip, for example.

(23) As viewed in the radial direction R, the metal insert part 28 is situated in each case on an outermost circumferential edge of the respective conveying helix portion 23 of the conveying helix segments 15 to 21. The aforementioned envelope E is thus defined by the metal insert parts 28 of the conveying helix 13. The outer edge 14, which is not provided with a reference sign in FIG. 5, is formed by means of the metal insert parts 28. Here, metal insert parts 28 of adjacent conveying helix segments 15 to 21, for example of the conveying helix segments 15 and 16, do not contact one another, with the result that the outer edge 14 is not continuous, but interrupted. This makes it possible to avoid noise formation due to contact between adjacent metal insert parts 28. Reduced wear of the conveying helix 13 can be achieved by means of the metal insert parts 28.

(24) Both embodiments of the drilling device 1 which have been explained above have the advantages listed below. The fact that the conveying helix segments 15 to 21 are manufactured from a plastics material means that it is possible, by comparison with a drilling device having a conveying helix made of a metal material, to achieve a significant reduction in noise pollution. Furthermore, as a result of using the plastics material, a weight reduction of the drilling device 1 can be achieved. Heating of the shank 6 is reduced on account of the reduced thermal conductivity of the plastics material in relation to a metal.

(25) The form-fitting engagement of the mating engagement portion 26 in the engagement portion 9 makes it possible for the conveying helix segments 15 to 21 to be locked and mounted in a simple manner. Furthermore, individual conveying shaft segments 15 to 21 can be replaced simply and rapidly, for example upon wear. It is possible by means of the elastomer ring 27 to achieve simple locking of the conveying helix segments 15 to 21 on the drill basic body 2 in the axial direction, that is to say in the longitudinal direction L1.

LIST OF REFERENCE CHARACTERS

(26) 1 Drilling device 2 Drill basic body 3 Drilling head 4 Cutting body 5 Center drill 6 Shank 7 Driving slot 8 Shaft 9 Engagement portion 10 Transition region 11 Engagement region 12 Shoulder 13 Conveying helix 14 Outer edge 15 Conveying helix segment 16 Conveying helix segment 17 Conveying helix segment 18 Conveying helix segment 19 Conveying helix segment 20 Conveying helix segment 21 Conveying helix segment 22 Base portion 23 Conveying helix portion 24 End side 25 End side 26 Mating engagement portion 27 Elastomer ring 28 Metal insert part E Envelope L1 Longitudinal direction L2 Longitudinal direction M Axis of symmetry R Radial direction