DRILLING JIG

Description

[0001] The present invention relates to a drilling device according to the preamble of claim 1. Such a drilling device is known from document EP 2876246 A1.

[0002] So-called bell drills can consist of a drill body with a drill head and a steel conveyor spiral that runs around the shaft of the drill body. The steel conveyor spiral can be attached to the drill body and connected to it either permanently or detachably. The steel conveyor spiral can be used to transport cuttings, such as rock flour, away from the drill head.

[0003] DE 34 05 070 A1 shows a rock drill with a drill head with a molded shaft. The shaft is surrounded by a tube at a radial distance from the drill head over most of its length, supporting a conveyor helix mounted on the tube's exterior. EP 0 201 724 A2 shows a replacement conveyor helix used in rock drills to convey cuttings. A T-profile beam is used to manufacture the replacement conveyor helix, the spirally wound transverse web of which forms the casing tube, and the vertical web of which forms the transport shoulder.

[0004] An object of the present invention is to provide an improved drilling device. DISCLOSURE OF THE INVENTION

[0005] Accordingly, a drilling device, in particular a bell-shaped drill, is proposed. The drilling device comprises a drill body and a conveying helix helically encircling the drill body, wherein the conveying helix is ​​divided into a plurality of adjacently arranged conveying helix segments.

[0006] Because the conveyor helix is ​​divided into segments, individual segments can be easily and quickly replaced, for example, due to wear, without the need for a costly complete replacement of the conveyor helix. Furthermore, the drilling device can be assembled and disassembled quickly and easily.

[0007] The drilling device is particularly suitable for use with a handheld power tool. The handheld power tool can be, for example, a drill, an impact drill, a hammer drill, a cordless screwdriver, a chisel hammer, or the like. The handheld power tool preferably comprises a motor for setting the drilling device in rotation. The handheld power tool preferably further comprises a fastening device configured to fasten the drilling device to the handheld power tool. The fastening device is, for example, a drill chuck.

[0008] The drilling device is preferably a bell drill, a hammer drill, a rock drill, or the like, or can be referred to as such. The drill body can also be referred to as a drill blank. The drill body preferably comprises a drill head with cutting elements and a center drill, as well as an insertion end, with the aid of which the drilling device can be coupled to the handheld power tool. A shaft is provided between the insertion end and the drill head, onto which the conveyor spiral segments are threaded. The conveyor spiral can also be referred to as a conveyor screw, conveyor helix, or conveyor spiral. The conveyor spiral can also be referred to simply as a spiral, screw, helix, or spiral. The term "helical" can also be replaced by the term "helical" or "spiral."

[0009] The term "divided" into the conveyor spiral segments means that the conveyor spiral segments are separate and unconnected components. This means that the conveyor spiral segments can be replaced individually or together. The sequence of the conveyor spiral segments on the drill body can be changed. The term "arranged next to each other" means that, viewed in a longitudinal direction of the drilling device, the conveyor spiral segments are arranged such that at least two conveyor spiral segments are positioned next to each other or adjacent to each other. However, the number of conveyor spiral segments is arbitrary. Preferably, at least two such conveyor spiral segments are provided. However, three, four, five, six, seven, or more conveyor spiral segments can also be provided.

[0010] According to one embodiment, the conveyor spiral segments are arranged loosely next to one another.

[0011] In particular, the conveyor spiral segments are not connected to one another. Therefore, the conveyor spiral segments are preferably arranged side by side without any connection. This means that the conveyor spiral segments can be separated from one another without the use of tools.

[0012] According to a further embodiment, the conveyor spiral is made of a plastic material.

[0013] The conveyor screw can also be referred to as a plastic conveyor screw. In particular, the individual conveyor screw segments are made of a plastic material. Accordingly, the conveyor screw segments can be referred to as plastic conveyor screw segments. For example, the conveyor screw segments can be cost-effective plastic injection-molded components. The plastic material can be, for example, polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), or another suitable plastic material. The plastic material is preferably a thermoplastic. Because the conveyor screw or the conveyor screw segments are preferably made of a plastic material, a significant reduction in noise pollution can be achieved compared to a drilling device with a conveyor screw made of a metal material.Furthermore, the use of the plastic material allows for a significant weight reduction of the drilling device compared to a drilling device with a metallic conveying screw, as mentioned above. Furthermore, heating of the insertion end is reduced due to the reduced thermal conductivity of the plastic material compared to a metal. This improves the handling of the drilling device. Alternatively, the conveying screw can also be made of another suitable material, such as a composite material. The conveying screw can also comprise a metal material and / or a ceramic material, or be made of such a material.

[0014] According to a further embodiment, the conveyor spiral segments are positively connected to the drill body.

[0015] In particular, the conveyor spiral segments are connected to the drill body in a rotationally fixed manner. This means that the conveyor spiral segments cannot be rotated around a central or symmetrical axis of the drilling device, but can be moved along the longitudinal direction of the drilling device. A positive connection is created by the interlocking or engaging of at least two connecting partners, in this case the conveyor spiral segments and the drill body.

[0016] According to the invention, the drill body has an engagement section, in particular an external hexagon, and the conveyor spiral segments each have a counter-engagement section, in particular a hexagon socket, which engages positively in the engagement section.

[0017] As an alternative to the external hexagon and the internal hexagon, any external polygon and internal polygon, for example, an external triangle or external square and, accordingly, an internal triangle or internal square, can also be provided. Alternatively, a toothing can be provided between the drill body and the feed screw segments as an engagement section and a corresponding counter-toothing can be provided as a counter-engagement section.

[0018] According to a further embodiment, each conveying helix segment has a base section through which the drill body is guided, and a conveying helix section that helically extends around the base section. The conveying helix sections preferably form an outer surface or outer edge of the conveying helix, which in particular defines an envelope or enveloping surface of the conveying helix. The enveloping surface is preferably cylindrical. The outer edge extends spirally around the axis of symmetry.

[0019] According to a further embodiment, the base section is hollow cylindrical and has two end faces oriented perpendicular to an axis of symmetry of the drilling device.

[0020] The end faces or end surfaces each form a base surface of the hollow cylindrical geometry of the base section. The base section is plugged or threaded onto the drill body, in particular onto the shank thereof. According to a further embodiment, the base section and the conveyor helix section are formed as one piece, in particular from a single material.

[0021] "One-piece" means, in particular, that the base section and the conveyor spiral section form a single component. "Integral" means, in particular, that the base section and the conveyor spiral section form a single component made entirely of the same material. Therefore, the conveyor spiral segments are preferably designed as cost-effective plastic injection-molded components.

[0022] According to a further embodiment, a pitch of the conveyor spiral is selected such that the conveyor spiral section rotates once around the base section.

[0023] Alternatively, the pitch of the conveyor spiral can also be selected so that the conveyor spiral section revolves around the base section several times.

[0024] According to a further embodiment, the conveyor spiral segments each have a metal insert located on the outside with respect to a radial direction of the drilling device.

[0025] The radial direction is oriented perpendicular to the axis of symmetry and points away from it. In particular, the metal insert defines the aforementioned envelope surrounding the conveyor spiral. This means that, viewed in the radial direction, the metal inserts of the conveyor spiral form the aforementioned outer edge of the conveyor spiral. The metal inserts prevent premature wear of the conveyor spiral. The metal inserts are provided, in particular, on the respective conveyor spiral sections of the conveyor spiral segments.

[0026] According to a further embodiment, metal inserts of adjacent conveyor spiral segments are out of contact.

[0027] This reliably prevents noise caused by contact between metal inserts of adjacent conveyor spiral segments. In particular, the outer edge of the conveyor spiral is not continuous, but interrupted.

[0028] According to a further embodiment, the metal insert is at least partially overmolded with material of the respective conveyor spiral segment.

[0029] This means that the metal insert is firmly bonded to the respective conveyor spiral segment. In bonded connections, the connecting partners are held together by atomic or molecular forces. Bonded connections are non-detachable connections that can only be separated by destroying the connecting elements and / or the connecting partners. Preferably, the metal insert is overmolded with the material of the respective conveyor spiral segment using a plastic injection molding process. This enables particularly cost-effective production of the conveyor spiral segments. Furthermore, a particularly high degree of durability of the connection between the metal insert and the conveyor spiral segment is ensured.

[0030] According to a further embodiment, the drilling device comprises an elastomer ring for locking the conveyor spiral segments to the drill body.

[0031] The elastomer ring can be made of rubber, a thermoplastic polyurethane, or the like, for example. The elastomer ring can be designed to spring-load the conveyor screw segments in the longitudinal direction of the drilling device. This reliably prevents relative movement between the conveyor screw segments, thus preventing unwanted wear.

[0032] According to a further embodiment, the conveyor spiral segments are arranged between the elastomer ring and a drill head of the drill body.

[0033] As previously mentioned, the conveyor spiral segments are threaded onto the shaft of the drill body, with the conveyor spiral segments resting on one side on the drill head and on one side on the elastomer ring.

[0034] According to a further embodiment, the elastomer ring rests on a shoulder surrounding the drill body.

[0035] Alternatively, a distance or gap can be provided between the shoulder and the elastomer ring so that the elastomer ring only rests against the shoulder when a force is applied to the conveyor spiral in the longitudinal direction.

[0036] Furthermore, a hand-held power tool with such a drilling device is proposed. SHORT DESCRIPTION OF THE CHARACTERS

[0037] The following description explains the invention using exemplary embodiments and figures. The figures show: Fig. 1 is a schematic view of an embodiment of a drilling device; Fig. 2 is a schematic view of an embodiment of a drill body for the drilling device according to Fig. 1 ; Fig. 3 a schematic sectional view of the drill body according to the section line III-III of Fig. 2 ; Fig. 4 a schematic sectional view of an embodiment of a conveyor spiral segment for the drilling device according to the section line IV-IV of Fig. 1 ; and Fig. 5 a schematic view of another embodiment of a drilling device.

[0038] Identical or functionally equivalent elements are indicated by identical reference numerals in the figures unless otherwise stated. EMBODIMENTS OF THE INVENTION

[0039] Fig. 1 shows a schematic view of an embodiment of a drilling device 1. The drilling device 1 is a bell drill, rock drill or hammer drill or can be referred to as such. The drilling device 1 comprises a Fig. 2 and 3The drill body 2 shown here. The drill body 2 can also be referred to as a drill shank or drill blank. The drill body 2 is made of metal, for example, a steel alloy.

[0040] The drill body 2 comprises a drill head 3 with cutting elements 4. The cutting elements 4 can comprise, for example, a hard metal or a ceramic material. With the aid of the cutting elements 4, a material to be machined, for example, rock or concrete, can be abrasively removed. The cutting elements 4 can, for example, be soldered to the drill head 3. Furthermore, the drill head 3 comprises a center drill 5 projecting beyond the drill head 3 in a longitudinal direction L2 of the drill body 2. The center drill 5 can also comprise a hard metal or a ceramic material.

[0041] The drill body 2 further comprises an insertion end 6, by means of which the drilling device 1 can be detachably connected to a handheld power tool. The handheld power tool can be, for example, a hammer drill, a chisel hammer, a core drill, or the like. The insertion end 6 comprises a plurality of driving grooves 7, which serve for the positive engagement of locking elements of the handheld power tool. A positive connection is created by the interlocking or engaging of at least two connection partners, in this case the driving grooves 7 and the locking elements.

[0042] A shank 8 of the drill body 2 extends in the longitudinal direction L2 between the drill head 3 and the insertion end 6. The shank 8 comprises an engagement section 9. The engagement section 9 can be an external polygon, in particular an external hexagon ( Fig. 3 ). The engagement section 9 is connected to the drill head 3 by means of a transition region 10 which is preferably circular in cross section.

[0043] Between the insertion end 6 and the engagement section 9, an engagement region 11 is provided, which is preferably circular in cross-section and is delimited from the insertion end 6 by a circumferential shoulder 12. The engagement section 9, the transition region 10 and the engagement region 11 are part of the shaft 8. The drill body 2 is constructed essentially rotationally symmetrically to a central or symmetry axis M. The longitudinal direction L2 runs parallel to the symmetry axis M or coincides with it.

[0044] Now returning to the Fig. 1 The drilling device 1 comprises, in addition to the drill body 2, a spiral, helical or helix-shaped conveyor helix 13 which encircles the drill body 2. The conveyor helix 13 is suitable for conveying drilling cuttings, for example rock flour, in a longitudinal direction L1 of the drilling device 1 away from the drill head 3 in the direction of the insertion end 6 of the drill body 2. The longitudinal direction L1 corresponds to the longitudinal direction L2. The longitudinal directions L1, L2 are in the orientation of the Fig. 1 and 2 from bottom to top, that is, from the drill head 3 in the direction of the insertion end 6. The drilling device 1 is also essentially constructed rotationally symmetrically to the axis of symmetry M. The conveyor spiral 13 can also be referred to as a conveyor helix, conveyor spiral or conveyor screw.

[0045] The conveyor helix 13 is assigned an envelope or enveloping surface E. The enveloping surface E is cylindrical with a circular base surface. The enveloping surface E is defined by an outer surface or outer edge 14 of the conveyor helix 13, which is arranged in a radial direction R at a distance from the axis of symmetry M and spirals around the axis of symmetry M. The radial direction R is oriented perpendicular to the axis of symmetry M and away from it.

[0046] The conveyor spiral 13 is divided into a plurality of adjacently arranged conveyor spiral segments 15 to 21. The number of conveyor spiral segments 15 to 21 is arbitrary. In particular, however, at least two such conveyor spiral segments 15 to 21 are provided. Fig. 1 shows seven conveyor spiral segments 15 to 21 threaded onto the shaft 8 of the drill body 2. The conveyor spiral segments 15 to 21 are arranged loosely next to one another. This means that the conveyor spiral segments 15 to 21 are not connected to one another and are designed as separate components. This allows for the replacement of individual conveyor spiral segments 15 to 21. The conveyor spiral segments 15 to 21 can be of different lengths or the same length when viewed in the longitudinal direction L1.

[0047] The conveyor spiral 13, and in particular the individual conveyor spiral segments 15 to 21, are preferably made of a plastic material. For example, the conveyor spiral segments 15 to 21 can be made of polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), or any other suitable plastic material. The plastic material is, in particular, a thermoplastic. For example, the conveyor spiral segments 15 to 21 can be cost-effective plastic injection-molded components. The conveyor spiral 13 can also be referred to as a plastic conveyor spiral.

[0048] Each conveying spiral segment 15 to 21 has, as shown with the conveying spiral segment 21, a tubular base section 22 attached to the drill body 2, in particular to the engagement section 9 of the shaft 8, and a conveying spiral section 23 helically extending around the base section 22. The conveying spiral sections 23 of all conveying spiral segments 15 to 21 thus form the conveying spiral 13 with the outer edge 14, which extends around the drill body 2. The base sections 22 are also part of the conveying spiral 13.

[0049] The base section 22 and the conveyor spiral section 23 of each conveyor spiral segment 15 to 21 are preferably formed as one piece, in particular from a single material. For example, the conveyor spiral segments 15 to 21, as previously mentioned, can be cost-effective plastic injection-molded components. The base section 22 is hollow-cylindrical and comprises two end faces or end sides 24, 25 oriented parallel to each other and perpendicular to the axis of symmetry M. The end sides 24, 25 are annular and form a base surface of the hollow-cylindrical geometry of the base section 22.

[0050] A pitch, in particular a thread pitch, of the conveyor spiral 13 is selected such that the respective conveyor spiral section 23 of each conveyor spiral segment 15 to 21 revolves once around the base section 22 assigned to it. Alternatively, the pitch can also be selected such that the conveyor spiral section 23 revolves several times, for example twice or three times, around the base section 22.

[0051] As previously mentioned, the conveyor spiral segments 15 to 21 are not connected to each other. According to the invention, the conveyor spiral segments 15 to 21 are positively connected to the drill body 2 in such a way that the conveyor spiral segments 15 to 21 are fixed to the drill body 2 in a rotationally fixed manner. As previously mentioned, the drill body 2 has the Fig. 2 and 3shown engagement section 9. Accordingly, the base sections 22 of the conveyor spiral segments 15 to 21 have a counter-engagement section 26 corresponding to the engagement section 9 ( Fig. 4 ). The counter-engagement section 26 can, as shown in the Fig. 4 shown, a polygon socket corresponding to the engagement section 9, in particular a hexagon socket.

[0052] As the Fig. 1 shows, the conveyor spiral segments 15 to 21 are threaded onto the drill base body 2 in such a way that a first conveyor spiral segment 15 rests against the drill head 3. The first conveyor spiral segment 15 is followed by a second to seventh conveyor spiral segment 16 to 21. The seventh conveyor spiral segment 21, in turn, is fixed relative to the shoulder 12 of the drill base body 2 by means of an elastomer ring 27. The elastomer ring 27 engages in the engagement region 11. Thus, the conveyor spiral segments 15 to 21 are axially fixed between the drill head 3 and the elastomer ring 27, viewed in the longitudinal direction L1. The conveyor shaft segments 15 to 21 are secured against rotation by means of the aforementioned engagement section 9 and the corresponding counter-engagement section 26.

[0053] After removing the elastomer ring 27, the feed screw segments 15 to 21 can be easily pulled off the drill body 2. The elastomer ring 27 can always be in contact with the shoulder 12 or only when a force acting in the longitudinal direction L1 is applied to the feed screw 13. In this case, a gap can be provided between the shoulder 12 and the elastomer ring 27.

[0054] Fig. 5 shows a further embodiment of a drilling device 1. The drilling device 1 according to the Fig. 5 differs from the drilling device 1 according to the Fig. 1 essentially only in that the conveyor spiral sections 23 of the conveyor spiral segments 15 to 21 each have a metal strip or metal insert 28 pointing away from the respective base section 22. The metal insert 28 is designed, for example, as a steel strip.

[0055] Viewed in the radial direction R, the metal insert 28 is located at an outermost circumferential edge of the respective conveyor spiral section 23 of the conveyor spiral segments 15 to 21. The previously mentioned envelope E is thus defined by the metal inserts 28 of the conveyor spiral 13. The Fig. 5 The outer edge 14, not provided with a reference symbol, is formed with the aid of the metal inserts 28. Metal inserts 28 of adjacent conveyor spiral segments 15 to 21, for example, conveyor spiral segments 15 and 16, do not contact one another, so that the outer edge 14 is not continuous but interrupted. This prevents noise caused by contact between adjacent metal inserts 28. The metal inserts 28 can be used to reduce wear on the conveyor spiral 13.

[0056] Both previously explained embodiments of the drilling device 1 have the advantages listed below. Because the conveyor helix segments 15 to 21 are made of a plastic material, a significant reduction in noise pollution can be achieved compared to a drilling device with a conveyor helix made of a metal material. Furthermore, the use of the plastic material allows for a weight reduction of the drilling device 1. Heating of the insertion end 6 is reduced due to the reduced thermal conductivity of the plastic material compared to a metal.

[0057] Due to the positive engagement of the counter-engagement section 26 in the engagement section 9, simple locking and assembly of the conveyor screw segments 15 to 21 is possible. Furthermore, individual conveyor shaft segments 15 to 21 can be easily and quickly replaced, for example, in the event of wear. With the help of the elastomer ring 27, simple locking of the conveyor screw segments 15 to 21 on the drill body 2 in the axial direction, i.e., in the longitudinal direction L1, is possible. LIST OF REFERENCE SYMBOLS

[0058] 1Drilling device 2Drill body 3Drill head 4Cutting body 5Center drill 6Inlet end 7Drive groove 8Shaft 9Engagement section 10Transition area 11Engagement area 12Step 13Fuel spiral 14Outer edge 15Fuel spiral segment 16Fuel spiral segment 17Fuel spiral segment 18Fuel spiral segment 19Fuel spiral segment 20Fuel spiral segment 21Fuel spiral segment 22Base section 23Fuel spiral section 24End face 25End face 26Counter-engagement section 27Elastomer ring 28Metal insert EEnvelope L1Longitudinal direction L2Longitudinal direction MSymmetry axis RRadial direction

Claims

1. Drilling device (1), in particular core drill, having a drill basic body (2) and a conveying helix (13) which runs helically around the drill basic body (2), wherein the conveying helix (13) is subdivided into a plurality of conveying helix segments (15-21) arranged next to one another, characterized in that the conveying helix (13) is manufactured from a plastics material, the conveying helix segments (15-21) each have a metal insert part (28) situated externally with respect to a radial direction (R) of the drilling device (1), and the metal insert part (28) is at least partially overmolded with material of the respective conveying helix segment (15-21), characterized in that the conveying helix segments (15-21) are connected to the drill basic body (2) in a form-fitting manner, and the drill basic body (2) has an engagement portion (9), specifically an outer hexagon, and the conveying helix segments (15-21) each have a mating engagement portion (26), specifically an inner hexagon, which engages in the engagement portion (9) in a form-fitting manner.

2. Drilling device according to Claim 1, characterized in that the conveying helix segments (15-21) are arranged loosely next to one another.

3. Drilling device according to either of Claims 1 and 2, characterized in that each conveying helix segment (15-21) has a base portion (22), through which the drill basic body (2) is guided, and a conveying helix portion (23) running helically around the base portion (22).

4. Drilling device according to Claim 3, characterized in that the base portion (22) is hollow cylindrical and has two end sides (24, 25) oriented perpendicularly to an axis of symmetry (M) of the drilling device (1).

5. Drilling device according to Claim 3 or 4, characterized in that the base portion (22) and the conveying helix portion (23) are formed in one piece, in particular in a materially integral manner.

6. Drilling device according to either of Claims 4 and 5, characterized in that a pitch of the conveying helix (13) is selected in such a way that the conveying helix portion (23) runs once around the base portion (22).

7. Drilling device according to one of the preceding claims, characterized in that metal insert parts (28) of adjacent conveying helix segments (15-21) are out of contact.

8. Drilling device according to one of Claims 1-7, characterized by an elastomer ring (27) for arresting the conveying helix segments (15-21) on the drill basic body (2).

9. Drilling device according to Claim 8, characterized in that the conveying helix segments (15-21) are arranged between the elastomer ring (27) and a drilling head (3) of the drill basic body (2).

10. Drilling device according to Claim 8 or 9, characterized in that the elastomer ring (27) bears against a shoulder (12) running around the drill basic body (2).