EP0846038A1

EP0846038A1 - Drilling tool

Info

Publication number: EP0846038A1
Application number: EP96929258A
Authority: EP
Inventors: Frank Stahl
Original assignee: Komet Praezisionswerkzeuge Robert Breuning GmbH
Current assignee: Komet Praezisionswerkzeuge Robert Breuning GmbH
Priority date: 1995-08-21
Filing date: 1996-08-15
Publication date: 1998-06-10
Also published as: US6095725A; JPH11511079A; WO1997006913A1; DE19632784A1

Abstract

The invention concerns a drilling tool for machine tools, said drilling tool comprising a drill shank (14) provided with a radially outwardly projecting feed helix (12). The drilling tool also comprises a drilling head (16) which is disposed at the end of the drill shank (14) and has two segment sections (20) which are delimited radially outwardly by partially cylindrical peripheral surfaces (22) and separated from each other by axially parallel chip grooves (18) which are adjacent in the peripheral direction. The drilling head further comprises at least two cutting plates (26) which are disposed at different radial spacings from the drilling tool axis and each have a cutting edge projecting at the end face beyond the drilling head (16). The chip grooves are delimited on the side of the cutting plates by an axially parallel radial chip-deflection surface (24) and by a chip-guide surface (42) which is disposed on the adjacent segment section (20) and lies opposite the chip-deflection surface and substantially parallel thereto. The chip-deflection surfaces (24) terminate at an axial spacing from the cutting edges (30) at a substantially radial rear free edge (46) and merge there into a chip-feed surface (50) which delimits the relevant segment section at the rear in the direction of the drill shank, rising helically to the following chip channel (18). The annular space between the chip-feed surface and the end (58) of the feed helix (12) at the drilling head end forms a chip-stowing space (48) from which the chips produced during drilling are carried away externally in portions by the feed helix (12).

Description

Drilling tool

description

The invention relates to a drilling tool for machine tools, in particular for machining workpieces made of metal or plastic of the type specified in the preamble of claims 1 and 3.

A drilling tool of this type is known (DE-A 42 14 528), which has a drill shaft that can be clamped onto a machine spindle, is provided with a feed spiral that delimits a chip-conveying groove, and has a drill head arranged on the end face of the drill shaft. The drill head has two segment channels which are delimited radially outwards by part-cylindrical peripheral surfaces which complement one another to form a common circumferential cylinder and are separated from one another by segment channels which adjoin in the circumferential direction and are essentially axially parallel and open in the chip discharge direction in the chip removal groove. Furthermore, the drill head has at least two cutting inserts, which are arranged at different radial distances from the drill axis with partially overlapping working areas, each in a recess in the segment parts in the area of an axially parallel radial chip guiding surface, preferably with the cutting surface flush with this, and each have an effective cutting edge projecting over the end face of the drill head, the cutting edge of the outermost cutting plate projecting radially beyond the part-cylindrical peripheral surface in question, and wherein the

ORIGINAL DOCUMENTS The drill head has a larger diameter on its circumferential cylinder than the drill shaft. A special alignment of the cutting plates, which partially overlap one another in the effective range of their cutting edges, ensures that the transverse forces which occur on the cutting edges during the drilling process are essentially canceled out against one another, so that bores are essentially guided without guidance Workpiece can be introduced. The centering is effected by means of a centering drill arranged centrally. The chip channels, which are axially parallel in the drill head and triangular in cross section, each open in the chip direction in a relatively steep helical chip conveyor groove in the drill shank, which are formed in the shank material. The chip conveying grooves are delimited at their edge by a conveying helix, which is used on the one hand to guide the drill in the borehole and on the other hand to limit the chip conveying grooves. Each chip channel is assigned its own chip conveyor groove in the drill shank, into which it merges in the direction of chip flow. In this construction, the chips are pressed outward under the action of a coolant through the chip conveying grooves. The design of the relatively wide conveying helix is intended to prevent chips from the chip conveying grooves from being distributed over the circumference of the drill shaft, since otherwise there is a risk of the chips being welded to the bore wall and the drill shaft and thus destroying the Bore and the drilling tool inspected. Another problem there is that the chip channel in the area of the inner plate has a relatively wide, forms a triangular chip space in cross section, which narrows backwards like a funnel in the direction of chip travel. This leads to the fact that the chip can develop relatively broadly when it is formed and then has to be pressed into the chip conveying groove using a deformation work. As a result, a large part of the thrust energy transferred to the chips during the machining process is lost in the form of deformation work and can no longer be used to remove the chips. In addition, the deformation forces are partially converted into transverse forces, which cause radial displacement of the drill head and thus a deterioration in the drilling performance and the drilling quality. For this reason, guide-free drills of this type can only be used for relatively short bores with a depth of up to 6 x D, where D means the diameter of the bore.

Proceeding from this, the object of the invention is to develop a drilling tool which can also be used for large drilling depths of 12 x D and more and which nevertheless ensures an effective and virtually transverse force-free chip sequence.

To achieve this object, the combinations of features specified in patent claims 1, 3 and 26 are proposed. Advantageous refinements and developments of the invention result from the dependent claims.

The solution of the invention is above all the idea ke is based on the fact that the relatively long flow and shear shavings that arise during the production of the borehole are transmitted before they are detached from the workpiece via the tool feed, a shear force that is used for chip removal under suitable geometric conditions can. Use is made of the knowledge that chip deformation, which leads to chip compression and the creation of transverse forces, must be avoided after chip formation. In order to achieve this, it is proposed according to the invention that the chips are introduced from their point of origin into an annular, axially extended chip storage space formed between the drill shank and the bore wall before at least some of them are separated from the workpiece , and that at least some of the chips from one end of the chip adjoining the chip storage space, with a smaller diameter than the bore protruding beyond the drill shank, co-rotated with the tool in the area between two of their curling or screwing windings are positively detected and are transported out of the bore essentially axially parallel with friction with the bore wall and sliding on the conveying helix. It can also be achieved that with the chips that form-fittingly slide on the conveyor helix, further chips hooked with them are transported out of the bore in portions.

In objective terms, this goal can be achieved in that the chip channels face and close to the chip guide surface on the cutting plate side This has essentially parallel-oriented cutting plate-mutual chip guide surfaces arranged on the adjacent segment part and / or that the cutting-plate-side chip guide surfaces end at an axial distance from the cutting edges of the cutting plates on a substantially radially oriented, preferably rounded, rear free edge and at this end in a die The relevant segment section passes backwards in the direction of the drill shaft delimiting, up to the next chip channel helically at an incline of less than 40 'in the chip removal direction. The axial extent of the chip guiding surfaces between the cutting edges and the free edge should be chosen to be relatively short and should correspond approximately to 1.5 to 3 times the diameter of the insert tip. This ensures that a predominant part of the flow or shear chips generated during the drilling process reach the chip conveying surface before they are completely separated from the workpiece. In order to facilitate the transfer of the chips to the chip conveyor surface, the chip guide surfaces should preferably have an axial extension 1.5 to 3 times greater than the neighboring chip guide surfaces and towards their rear end in the direction of the chip guide surface and chip conveyor surface adjacent segment section must be bent.

In order to be able to modularly assemble the drilling tool in adaptation to the machining task to be carried out, it is proposed according to a preferred embodiment of the invention that the drilling head be detachably connected to the Drill shaft is connected and / or that the drill shaft consists of at least two shaft sections which are connected to one another in pairs at an axial separation point, the associated conveying spiral sections in the area of the separation point should merge into one another in a step-free and / or gap-free manner to avoid chip jam.

On the side of the drill axis in the area between the chip guide surface and the chip guide surface, the chip channels are expediently delimited by a chip removal surface which widens conically from the entry point on the cutting edge side up to the diameter of the drill shaft. It is important here that the chip storage space adjoining the chip channels in the direction of chip removal widens compared to the cross section of the chip channels, so that the incoming chips can be inserted into the chip storage space almost without force.

Since the chip guiding surfaces block the immediate machining and assembly access to the neighboring chip guiding surfaces, additional measures must be taken which enable the cutting plate seats to be manufactured and the cutting plates to be assembled. These measures can consist, for example, of the cutting plates being arranged in at least one interchangeable cassette which is detachably fastened to the segment parts of the drill head and which in turn can be inserted into a corresponding recess in the segment parts. Additionally or alternatively, the part of the segment parts containing the chip guide surface can be separated as a separate part with the relevant segment part. bar-connected filler, which advantageously consists of a suitable hard material.

The design of the drill head according to the invention makes it possible for outlet nozzles for a coolant to be arranged on the end face of the segment parts in the vicinity of the chip guiding surfaces, obliquely in the direction of the cutting inserts. The outflowing coolant makes an additional contribution to chip removal.

For centering the drill head in the bore, it is particularly advantageous in deep hole drilling if the drill head has an exchangeable centering drill arranged axially centrally and projecting axially beyond the end face and the effective cutting edges of the cutting inserts. In this case, the working area of the radially innermost cutting insert should reach that of the centering drill and overlap it somewhat. The centering drill can also be provided with a coolant hole which essentially exits axially in the vicinity of the drill tip.

A preferred embodiment of the invention provides that the conveyor helix has a larger diameter than the drill shaft and a smaller diameter than the drill head. The width of the conveying helix should be less than 1/5, preferably less than 1/10 of its pitch defining the width of the chip conveying groove. The resulting and from the funding The penetrated annular space between the drill shank and the bore wall should be dimensioned so that the chips fit through the annular space and can be positively grasped by the rotating feed screw on their curl or screw turns. For this purpose, the conveyor helix expediently has a smooth surface which is preferably rounded in cross section. In principle, the conveyor spiral can also have a triangular or square cross section, preferably with rounded edges. For example, it can be designed as a helically wrapping wire, preferably welded to the cylindrical drill shaft, wherein the coiled wire can also be attached to the drill shaft in a non-slip manner and can only be fastened, preferably welded, to the shaft only at its ends. A further preferred embodiment of the invention provides that the conveying helix is arranged on the lateral surface of a tube piece which can be detachably plugged onto the drill shaft. This embodiment has the advantage that pipe sections with differently designed and dimensioned conveying spirals can easily be exchanged for one another in adaptation to the chip forms occurring during the drilling process.

At its end on the drill head side, the conveying helix expediently has an axial distance from the chip conveying surfaces of the drill head, so that an axial chip storage space is formed for the chips, in which larger and smaller chips can be chained in portions, before they reach the one Funding spiral are recorded. The chips are then removed due to the friction largely axially on the bore wall under the action of the rotating feed screw. The pitch angles of the conveying helix and the chip-conveying surface on the drill head side are expediently chosen to be approximately the same size. They are preferably less than 25 °.

The invention is explained in more detail below with reference to the drawing. Show it:

Fig. La and b show two side views of a drilling tool made up of two 90 ^* against each other obligations twisted Rich¬;

2 shows a plan view of the drill head of the boring tool according to FIGS. 1 a and b;

3 shows a side view of a drilling tool with a removable drilling head and modularly assembled shaft sections.

The drilling tool shown in the drawing essentially consists of a drill shaft 14 that can be clamped on a machine spindle (not shown), is provided with a feed spiral 12 that delimits a chip conveyor groove 10, and a drill head 16 that is preferably detachably arranged on the end of the drill shaft 14 two segment parts 20 separated from one another in the circumferential direction by axially parallel chip channels 18, which are delimited radially outwards by partially cylindrical circumferential surfaces 22. Furthermore, in the area of the axially parallel, radial chip guiding Surfaces 24 of the chip channels 18 each have three cutting plates 26 which are at a radial distance from one another and from the drill axis, the rake faces 28 of which are aligned with the relevant rake face 24 in the exemplary embodiment shown and their effective cutting edges 30 on the end face above the drill head 16 survive. The cutting plates 26 are arranged in groups of three each in an interchangeable cassette 32, which are arranged in a corresponding recess 34 in the drill head 16 and are clamped to the latter by means of screws 36. The cutting edge 30 of the radially outermost cutting plate 26 'protrudes radially slightly beyond the peripheral surface 22 of the relevant segment section 20 and determines the bore diameter D. In an axis-central bore of the drill head 16, a center drill 38 is additionally detachably arranged, which with its tip protrudes axially beyond the end face of the drill head 16 and the cutting edges 30 of the cutting plates 26, 26 '.

As can be seen in particular from FIGS. 1 a and b, the drill head 16 has a larger diameter than the drill shaft 14. In this way, during the drilling process, an annular space 40, which extends along the drill shaft 14 and is penetrated by the conveying helix 12 and is delimited on the outside by the wall of the bore, results through which the chips generated during the drilling process can be removed.

The chip channels 18 of the drill head each have a chip guide surface 24 on the cutting plate side. The chip guide surface 42 on the opposite side of the cutting plate opposite to the cutting plate and arranged between the chip guide surface 24 and the chip guide surface 42, which is essentially parallel to this and arranged on the adjacent segment part 20, is conical from the cutting edge-side entry point to the diameter of the drill shaft 14 expanding chip removal surface 44. The chip guide surface and the chip removal surface ensure that the chips cannot expand in an uncontrolled manner when they are formed, so that they pass through the annular space 40 without deformation and compression.

The chip guide surfaces 24 end at a relatively short axial distance from the cutting edges, which corresponds approximately to 1.5 to 3 times the diameter of the insert tip, at an essentially radially oriented rear free edge 46, to which an enlarged part is formed Chip storage space 48 is connected to a chip conveying surface 50 which delimits the relevant segment section 20 backwards in the direction of the drill shank 14 and which is helical up to the next chip channel 18 at an angle of inclination α of approximately 20 ° in the direction of chip travel. The chip guide surfaces 42 are in their axial extent 1.5 to 3 times larger than the adjacent chip guide surfaces 24 and are bent towards their rear end 52 in the direction of the chip guide surface 24 and chip conveying surface 50 of the adjacent segment part 20. The inner edges between the chip removal surface 44 and the adjacent chip guiding, guiding and conveying surfaces 24, 42, 50 are rounded and form warped Transitions for a smooth chip flow.

On the end face of the segment parts, in the vicinity of the chip guiding surfaces 42, outlet nozzles 54 for a cooling lubricant are arranged obliquely in the direction of the cutting plates 26. Further exit points 56 for cooling lubricant are located near the tip of the center drill 38. The cooling lubricant emerging at the outlet nozzles 54, 56 has the task, in addition to the cooling, of supporting the chip flow through the chip channels 18 and through the annular space 40.

However, the removal of chips from curly and helically wound chips preferably takes place via the conveyor helix 12. For this purpose, the conveyor helix has an outer diameter dw which is larger than the shaft diameter ds but smaller than the bore diameter D.

(see Fig. la and b). Furthermore, the width b of the conveyor spiral 12 is considerably smaller than its pitch w + b defining the width w of the chip conveying groove 10. The conveyor helix 12 can be integrally formed on the drill shaft 14 or can be designed as a helically wrapping wire around the cylindrical drill shaft and welded to it. At its end 58 on the drill head side, the conveyor helix 12 ends at a distance from the helical chip conveyor surfaces 50 of the drill head and thereby delimits the helix-free chip storage space 48 °. The drilling tool shown in FIG. 3 differs from the drilling tool according to FIGS. 1 a and b in that the drilling head 16 is detachably connected to the drill shaft 14 at a separation point 60 and in that the drill shaft 14 consists of several, in pairs, at separation points 62, 64 interconnected shaft sections 14 ', 14'',14''' is composed. To avoid chip jam, the conveyor spiral sections 12 ', 12''merge into one another in the region of the separation point 62 without steps and gaps. It is thus possible to assemble the drilling tool in a modular manner to match the machining task to be carried out.

The drilling tool described is advantageously used for deep hole drilling in workpieces, in which relatively long, helical or curly flowing chips are produced during the drilling process. A part of the flow chips is guided over the chip guide surfaces and the chip removal surfaces 44 through the chip channels 18 into the chip storage space 48 in the region of the chip conveying surface 50 before they are separated from the workpiece. As a result, the thrust force transferred to the chip by the advance of the workpiece is used to remove the chips largely without compaction or deformation work. Smaller and larger chips get caught in the chip storage space 48 and are gripped in portions by the conveying helix and conveyed approximately axially outward from the annular space 40. The conveyor helix engages positively in the turns of the chips. The friction on the bore wall ensures that the chips slide on the conveyor helix 12 and are transported out of the annular space 40 almost axially parallel. The cooling lubricant flow only has a supporting function.

In summary, the following can be stated: The invention relates to a drilling tool for machine tools with a drill shaft 14 provided with a radially outwardly projecting conveying helix 12 and a drill head 16 arranged on the end face of the drill shaft 14. The drill head has two radially outwards through partially cylindrical peripheral surfaces 22 limited and separated by peripheral edges, substantially axially parallel chip channels 18 separated segments 20 and at least two arranged at different radial distances from the drill axis, each containing a cutting edge protruding beyond the drill head 16 cutting plates 26. The chip channels are delimited on the side of the cutting plates by an axially parallel radial chip guide surface 24 and by a chip guide surface 42 which is opposite and essentially parallel to the chip guide surface and is arranged on the adjacent segment part 20. The chip guide surfaces 24 terminate at an axial distance from the cutting edges 30 at a substantially radially oriented rear free edge 46 and pass there into a chip conveying surface 50 which delimits the relevant segment section backwards in the direction of the drill shank and increases helically up to the next chip channel 18. The annular space between the chip conveying surface and the end 58 of the conveying screw 12 on the drill head side forms a chip storage space 48, from which the chips generated during the drilling process are removed in portions via the conveying helix 12 to the outside.

Claims

claims

1. Drilling tool for machine tools with a drill shaft (14) that can be clamped on a machine spindle and that has a conveyor shaft (12) that delimits a helical chip removal groove (10), and with a drill head (16) that is arranged on the end face of the drill shaft (14) ), which delimited two partially cylindrical peripheral surfaces (22) extending radially outwards through a common peripheral cylinder and by means of chip channels (18) adjacent in the peripheral direction and aligned essentially axially parallel and opening in the chip discharge direction in the chip removal groove (10) Segment parts (20) separated from one another and at least two working areas partially overlapping each other at different radial distances from the drill axis in each recess of the segment parts (20) in the area of an axially parallel, radial chip guide surface (24), preferably with the chip surface aligned with this (28) arranged, each with at least one end face r has cutting plates (26, 26 ') containing the effective cutting edge (30) projecting from the drilling head (16), the cutting edge (30) of the outermost cutting plate (26') projecting radially beyond the relevant partially cylindrical peripheral surface (22) and the drill head (16) has a larger outer diameter than the drill shank (14), characterized in that the chip channels (18) are opposite and substantially parallel to the chip guide surface (24) on the cutting plate side have aligned chip guide surface (42) arranged on the adjacent segment part (20),

Drilling tool according to claim 1, characterized gekennzeich¬ net that the chip guide surfaces (24) at an axial distance from the cutting edges end at a substantially radially aligned rear free edge and at this in a relevant segment section (20) backwards in the direction of the drill shank ( 14) pass into the chip-conveying surface (50), which increases helically up to the next chip channel (18) at an incline angle (α) of less than 40 ° in the direction of chip removal.

Drilling tool for machine tools with a drill shaft (14) which can be clamped on a machine spindle and which has a conveying helix (12) delimiting a helical chip removal groove (10), and with a drill head (16) arranged on the end face of the drill shaft (14), the two radially outwardly delimited by part-cylindrical peripheral surfaces (22) which complement one another to form a common peripheral cylinder and are separated from one another by segment portions (20) which are adjacent in the peripheral direction and are aligned essentially axially parallel and in the chip discharge direction into the chip removal groove (10). and at least two, at different radial distances from the drill axis with partially overlapping working areas each in a recess of the segment parts (20) in the area of an axially parallel, radial chip guide surface (24), preferably - Il ^¬

It has cutting plates (26, 26 ') which are arranged to this flush rake face (28) and each have at least one effective cutting edge (30) projecting over the end face of the drilling head (16), the cutting edge (30) of the outermost cutting plate (26 ') protrudes radially over the relevant partial cylindrical peripheral surface (22) and the drill head (16) has a larger outer diameter than the drill shaft (14), characterized in that the chip guide surfaces (24) are axially spaced from the cutting edges end at an essentially radially oriented rear free edge and at this end into a segment (20) which limits the rear in the direction of the drill shank (14) and is helical up to the next chip channel (18) at an inclination angle (α) of less than 40 '' Pass the chip conveying surface (50) that increases in the direction of chip removal.

4. Drilling tool according to one of claims 1 to 3, da¬ characterized in that the axial extension of the chip guide surface (24) between the effective cutting edges (30) and the free edge (46) 1.5 to 3 times the Circumferential insert diameter corresponds.

5. Drilling tool according to one of claims 1 to 4, da¬ characterized in that the chip guide surfaces

(42) have an axial extension preferably 1.5 to 3 times greater than the adjacent chip guide surfaces (24). 6. Drilling tool according to one of claims 2 biε 5, da¬ characterized in that the chip guide surfaces

(42) are bent toward their rear end (52) in the direction of the chip guide surface (24) and chip conveying surface (50) of the adjacent segment part (20).

7. Drilling tool according to one of claims 1 to 6, da¬ characterized in that the chip channels (18) on the side of the Bohrerachεe in the area between Span¬ guide surface (24) and chip guide surface (42) by a from the cutting edge-side entry point are limited from the conical chip removal surface (44) which widens up to the diameter of the drill shaft (14).

8. Drilling tool according to one of claims 1 to 7, da¬ characterized in that the cutting plates (26, 26 ') are arranged in at least one on the segment parts (20) of the drill head (16) detachably fastened interchangeable cassette (32).

9. Drilling tool according to one of claims 1 to 8, da¬ characterized in that the chip guide surface (42) containing part of the segment parts (20) as a separate, releasably connected to the relevant segment part, preferably consisting of a hard material filler is trained.

10. Drilling tool according to one of claims 1 to 9, da¬ characterized in that the drill head (16) one Axially centrally arranged, interchangeable center drill (38) over the end face of the drill head and the effective cutting edges (30) of the cutting plates (26, 26 ').

11. Drilling tool according to claim 10, characterized gekennzeich¬ net that the working area of the radially innermost cutting plate (26) to that of the centering drill (38) reaches and overlaps this.

12. Drilling tool according to one of claims 1 to 11, da¬ characterized in that on the end face of the segment parts (20) in the vicinity of the chip guide flat (42) obliquely in the direction of cutting plates (26, 26 ') pointing outlet nozzles (54) are arranged for a coolant.

13. Drilling tool according to one of claims 10 to 12, characterized by at least one penetrating the centering drill (38) essentially axially parallel, in the vicinity of the drill tip, open coolant bore (56).

14. Drilling tool according to one of claims 1 to 13, characterized in that the conveyor helix (12) has a larger diameter than the drill shaft (14).

(d W> dΞ) and a smaller diameter than that

Has drill head (16) (dw <D).

15. Drilling tool according to one of claims 1 to 14, characterized in that the width (b) of the conveying derwendel (12) is less than 1/5, preferably less than 1/10 of their pitch defining the width (w) of the chip conveyor groove (10).

16. Drilling tool according to one of claims 1 to 15, characterized in that the conveying helix (12) has a smooth surface which is preferably rounded in cross section.

17. Drilling tool according to one of claims 1 to 16, da¬ characterized in that the conveying helix (12) as the cylindrical drill shaft (14) is helically wrapped around, preferably formed on this welded wire.

18. Drilling tool according to one of claims 1 to 17, characterized by the fact that the helix (12) designed as a coiled wire is attached to the drill shaft (14) in a non-slip manner and its ends are attached, preferably welded, to the drill shaft (14) .

19. Drilling tool according to one of claims 1 to 18, da¬ characterized in that the conveyor helix (12) on the lateral surface of a releasably on the drill shaft

(14) is arranged on a pluggable pipe section.

20. Drilling tool according to one of claims 1 to 19, characterized in that the conveying helix (12) has a polygonal cross section, preferably a triangular or square cross section. 21. Drilling tool according to one of claims 1 to 20, da¬ characterized in that the conveying helix (12) at its boring head end (58) to form an axial chip storage space (48) at an axial distance from the chip conveying surface (50) of the drill head (16 ) ends.

22. Drilling tool according to one of claims 1 to 21, characterized by the fact that the pitch angle (β, α) of the conveying helix (12) and the chip-conveying surface (50) on the drill head side are approximately the same size.

23. Drilling tool according to claim 22, characterized gekennzeich¬ net that the pitch angle (ß) of the spiral conveyor

(12) is less than 40 ', preferably less than 25 °,

24. Drilling tool according to one of claims 1 to 23, da¬ characterized in that the drill head (16) is detachably connected to the drill shaft (14).

25. Drilling tool according to one of claims 1 to 24, characterized by the fact that the drill shank (14) consists of at least two shank sections which are connected to one another in pairs at an axial separation point (62, 64)

(14 ', 14' ', 14' ''), the associated sections (12 ', 12' ') of the conveying helix (12) being stepped in the region of the separation point (62) and / or passing into one another without gaps .

26. Method for removing in particular during a drilling process with a rotating drilling tool one of claims 1 to 25, resulting in the production of a bore, preferably in the form of flow chips, curly or screw-shaped chips, characterized in that the chips originate in a ring-shaped, axially expanded area formed between a drill shaft and the bore wall Chip storage space (48) is introduced before at least some of them are separated from the workpiece, and that at least some of the chips have a smaller diameter than the bore from one end of the chip space (48) Above the drill shaft projecting helix (12) rotated with the drilling tool in the area between two curl or screw turns, positively gripped and transported out under the friction with the bore wall and sliding on the helix essentially axially parallel to the bore.

27. The method according to claim 26, characterized in that with the chips on the feed helix (12) positively sliding, further hooked chips are transported out of the bore in packets.