WO2016091431A1

WO2016091431A1 - Drilling tool

Info

Publication number: WO2016091431A1
Application number: PCT/EP2015/073513
Authority: WO
Inventors: Javier Ibarra; Pat Mcauliffe
Original assignee: Robert Bosch Gmbh
Priority date: 2014-12-09
Filing date: 2015-10-12
Publication date: 2016-06-16
Also published as: DE102014225320A1; CN107000073B; CN107000073A; DE102014225320B4; EP3229999A1

Abstract

The invention relates to a drilling tool, in particular a metal drilling tool, comprising at least one groove, in particular a spiral-shaped groove, which runs about an axis of the drilling tool, and comprising an end region with at least one end surface and at least one main cutting element, which is formed between at least one cutting surface of the groove and the at least one end surface. The at least one groove has at least one recess next to the end region, in particular adjacent to the end region, in particular the at least one end surface. According to the invention, the recess is formed in the at least one groove using a deformation method.

Description

Description title

The invention relates to a drilling tool, a production method and an apparatus for producing a drilling tool, in particular a metal drilling tool, having at least one, in particular helical, groove extending around an axis of the drilling tool and having an end region with at least one end face and at least one main cutting element. between at least one rake face of the groove and the at least one

End face is formed.

PRIOR ART The DIN (German Institute for Standardization) 1412 A discloses a drilling tool with at least one helical groove extending along an axis of the drilling tool and with an end region with at least two end faces and at least one cutting edge. Adjacent to the end region, the groove of the drilling tool has a chamfer, which is formed by a grinding process. The disadvantage here is the additional grinding effort.

Disclosure of the invention

The invention is based on the object with simple production engineering measures a drilling tool for a machine tool, in particular a

Hand tool, so that an increased throughput in the production of the drilling tool is achieved with improved drilling properties. The problem is solved with a drilling tool, in particular

A metal boring tool having at least one, in particular helical, groove extending around an axis of the boring tool and an end region having at least one end face and at least one main cutting element arranged between at least one rake face of the groove and the at least one groove

End face is formed. The at least one groove has adjacent, in particular adjoining, at least one depression to the front region, in particular to the at least one end surface. According to the invention, the trough is formed by a forming process in the at least one groove.

The invention makes it possible to provide a drilling tool with a depression which minimizes the radial extent of the drilling tool, in addition to which the local strength of the depression is increased by the forming process.

As a result, a pressing force required for drilling in the drilling operation of the drilling tool on the drilling tool and thus on the machined

Workpiece reduced. Furthermore, it is prevented by the drilling tool according to the invention that the drilling tool slips when drilling a position to be drilled on the workpiece and thereby a borehole or a Bohrvorschub arises at an unscheduled position.

By the forming process further material of the drilling tool is solidified in the immediate vicinity of the trough, in particular work hardened, so that material parameters or material strengths are increased locally. Accordingly, the trough, not as already described in the prior art, introduced by a grinding process that not least requires an additional manufacturing step, but according to the invention introduced by a forming process in the groove of the drilling tool. A disadvantage of the prior art is accordingly the additional grinding costs, which previously represented an unavoidable additional effort in the production of a drilling tool with a groove and a trough. This grinding effort is eliminated by at least one forming tool a forming device, in particular a rolling device, not only the groove ausformt, but also forms the at least one trough in the groove of the drilling tool in a same or in a subsequent process step. Furthermore, in a single

Process step with a first section of the forming tool, in particular the forging disc, a first deformation of the grooves and with a second portion a second deformation of the trough into the blank or the drilling tool are introduced. The drilling tool according to the invention is formed at least in one piece. The

Drilling tool is divided into a receiving area and a work area. The receiving area of the drilling tool is intended to be received in a receiving device of a machine tool, in particular a hand tool machine. The working area of the drilling tool is intended to work on workpieces. It has the

Working area on at least one groove, which extends spirally around an axis and opens into a frontal area. The end region has at least one end face and at least one main cutting element. The

Main cutting element is formed at least substantially between a rake face of the groove and the at least one end face. The at least one groove of the working area in this case has at least one trough which is adjacent, in particular adjacent, formed to the end region. The trough is formed by a forming process in the at least one groove. Under a "radial extent" is in this context a

Extension, in particular a distance, preferably a first

Touch point, the axis of the drilling tool, for example, to the at least one trough or the at least one groove are understood. The radial extension of the trough or the groove may be formed as a radius of a supporting cross section of the drilling tool. The supporting cross-section is for power transmission, in particular torque or

Torque transmission, trained. The supporting cross-section may be circular, in particular as a circle, preferably as a circular surface, be formed, and extend transversely, in particular orthogonal, to the axis of the drilling tool in a plane. In particular, a radial

Extension of the supporting cross-section bounded by the groove and / or the trough. The radial extension of the supporting cross section may change along the axis of the drilling tool at least in sections, in particular increase or decrease. Alternatively, the radial

Extension of the supporting cross-section of at least the groove and / the trough stay the same along the axis of the drilling tool. Thus, the supporting cross section of the drilling tool along the axis of the drilling tool, in particular the working area, form a supporting body, the at least partially cylindrical or sections

is frusto-conical. The radial extent of the bearing

Cross-section of the groove may be up to 40%, in particular up to 30%, preferably up to 20%, preferably up to 15%, particularly preferably up to 10%, in relation to the maximum radial extension of the drilling tool. The radial extent of the supporting cross-section of the trough may be up to 30%, in particular up to 20%, preferably up to 10%, preferably up to 8%, particularly preferably up to 5%, in relation to the maximum radial extension of the drilling tool.

In this context, a "forming process" is to be understood as meaning a process in which an elastic and / or plastic deformation by means of a massive forming, in particular a

Material displacement and / or a material accumulation of the workpiece is achieved. Under a "massive forming" is a process such as rolling, drop forging, cold forming, extrusion, forging

(Freifomschmieden), upsetting or roll forming understood. In this case, the workpiece to be deformed by a forming tool, such as by at least one hammer or by at least one disc,

in particular, a forging disc, a forming device to be deformed. For example, two or more forming tools can be pressed onto the workpiece to be deformed or a blank. Thus, a desired deformation or formation of the groove and / or the trough can be achieved. An arrangement in a tool device of the at least one forming tool can be found, for example, in EP 0 792 705 A2, which describes how a groove of a drilling tool can be produced. However, it is not known how a trough, if it were provided, could be manufactured without additional effort.

In this context, a "forming tool" is to be understood as meaning a tool of a device for producing drilling tools, which is used for introducing a deformation of the drilling tool to be produced is trained. The at least one forming tool may be formed as a disc. The at least one disc can be designed as a forged disc or as a rolling disk. The disc may also be formed roller-shaped. In particular, the disc may be formed like a circle and thus do not extend completely around a tool axis.

In an alternative embodiment, at least one pin can be formed instead of at least one disk, which provides the necessary forming performance. The pin can press or squeeze a depression into a groove and shape it up to the end region, in particular to the end face.

The dependent claims give appropriate refinements of

according to the invention drilling tool.

It may be expedient that the trough, in particular a main extension of the trough, is formed at least substantially along, in particular parallel to, the axis of the drilling tool. Furthermore, it may be expedient that the trough, in particular a main extension of the trough, is formed at least substantially transversely to the axis of the drilling tool. In particular, the trough, in particular the main extension of the trough, be formed at an angle to the axis of the drilling tool. Preferably, a main extension of the trough can run in a spiral around the axis. Depending on the workpiece to be machined, it may be advantageous to adapt a main extension of the trough of the drilling tool to the material to be processed.

Preferably, the trough may be formed angled to the axis of the drilling tool. As a result, the trough can extend to the forehead area tapering. Particularly preferably, the trough, in particular a

Trough surface, opposite the groove, in particular a groove surface, angled or radially spaced formed. Preferably, the trough may be angled closer to the axis and / or to the groove and / or radially spaced. Thus, a larger transport volume is formed, which is provided for the transport of drilling dust. Thus, the accumulated drill dust is quickly conveyed out of the well, so that the drilling dust does not accumulate during drilling. Furthermore, the trough can at least partially adjoin at least one end face. As a result, a shortened cross-cutting element, running transversely to the main cutting element, of the drilling tool can be formed, which reduces the at least one end face in a region adjacent to the axis of the drilling tool, in particular a central region.

As a result, the drilling tool can apply an increased contact pressure with the same contact force of the drilling tool to the workpiece to be drilled as a result of the reduced end face. Likewise, the radial extent of the groove can be designed to be consistent with increasing distance from the end region. In particular, the radial extent of the groove can be formed continuously or stepwise with increasing distance from the end region. Furthermore, the radial extension of the trough with increasing distance from the end region, in particular at least in sections, be designed to be consistent.

Preferably, the radial extent of the trough with increasing

Distance from the forehead, in particular at least partially, continuously or stepwise increasingly be formed. It is thereby achieved that the radial extension of the drilling tool, in particular of the transverse cutting element, is minimal at the end region. This can do that

Drill tool at the front area have a taper, which is particularly advantageous when machining workpieces. Likewise, an increased stability is achieved in the entire drilling tool, since the trough only adjacent, in particular adjacent, extends to the end region.

Preferably, the minimum radial extent of the depression relative to the minimum radial extent of the groove can be up to 40%, in particular up to 30%, preferably up to 20%, preferably up to 10%, particularly preferably up to 5%. , reduce. In this way, an advantageous endabaugegetreues drilling tool can be produced, which has a minimum radial extent to the end region. As a result, an additional grinding operation or an additional grinding effort to form this advantage can be avoided. Thus, with a low device and manufacturing cost, a drilling tool can be made with a trough having an improved strength characteristic. There can be an increasing Increased degree of deformation in near-edge material areas of the trough

Strengths of the material can be achieved by solidification of the material.

Furthermore, it is proposed that the trough extend axially with respect to the maximum axial extent of the drilling tool up to 10%, in particular up to 8%, preferably up to 6%, preferably up to 5%. Further, the radial extent of the trough with respect to the maximum radial extent of the drilling tool by up to 50%, in particular up to 40%, preferably up to 30%, preferably up to 20%, particularly preferably up to 10%, extend. As a result, the complexity of the forming process or the rolling process is minimized because the trough only in one for

Face region adjacent, in particular adjacent, area is formed and not in the entire groove. As a result, the forming tool can be made simpler. Thus, a forming tool, in particular at least one forging disc, which is provided for forming the groove, form a further deformation in the form of the recess in the groove by a simple control of the device.

In particular, a, in particular axial, main extension of the trough with respect to a transverse extent by up to 500%, in particular by up to 400%, preferably by up to 300%, preferably by up to 200%, more preferably by up to 150%, be formed ,

Preferably, the transverse extent of the trough with respect to the maximum radial extent of the drilling tool by up to 70%, in particular by up to 55%, preferably by up to 40%, preferably by up to 30%, particularly preferably by up to 15%, such for example, 10% or 7%.

Preferably, the maximum axial extent of the trough may be up to 25%, in particular up to 30%, preferably up to 40%, preferably up to 45%, particularly preferably up to 50%, of the maximum radial

Extension of the drilling tool extend. Particularly preferred may be the maximum radial extent of the trough with respect to the maximum radial extent of the drilling tool

advantageously by up to 70%, in particular by up to 55%, preferably by up to 35%, preferably by up to 20%, particularly preferably by up to 10%, such as 8% or 5%, extend.

Furthermore, the maximum axial extent of the trough with respect to the maximum axial extent of the drilling tool by up to 20%,

in particular by up to 10%, preferably by up to 8%, preferably by up to 6%, more preferably by up to 4%, such as 2% or 1% extend.

By adjusting the extension of the trough of the drilling tool, the trough can be optimally adapted for different applications.

Furthermore, the minimum radial extent of the depression can be up to 50%, in particular up to 40%, preferably up to 30%, preferably up to 20%, particularly preferably up to 10%, compared to a minimum radial extent of the groove. , such as 8% or 5%, decrease. This ensures that the trough 31, the radial extent of the

Querschneidelements 29 minimized and forms a transport volume.

Particularly preferably, the trough, in particular at least substantially, be formed in a transport surface of the groove. This is advantageous because the main cutting element is at least substantially not limited by the trough, so that a homogeneous course of the main cutting element is provided.

Another aspect of the invention relates to a method of manufacturing the drilling tool.

A method for producing a drilling tool and an arrangement of a tool device of the at least one forming tool can

For example, EP 0 792 705 A2, which describes how a groove of a drilling tool can be produced. In one embodiment with two grooves and / or two wells exactly two forming tools can be provided.

Hereinafter, an embodiment of a drilling tool with two grooves, each with a trough will be described. However, the invention should not be limited to this embodiment, but rather to others

Be expandable embodiments with only one or more grooves.

By the method grooves and / or depressions by means of two

are formed opposite forming tools whose tool axes lie to each other in at least substantially parallel tool axis planes. The forming tool has, in particular, an outer area formed as a circumference, which delimits at least substantially the radial extension of the forming tool. The distance of the outer region of two forming tools to one another can thereby determine the load-bearing cross section of the manufactured drilling tool. This is accomplished by placing a cylindrical blank of circular cross section between the

Forming tools passed, in particular pulled through, is. The forming tools rotate to each other in opposite directions to pass through the blank. The outer region, in particular an outer surface of the outer region, preferably a forming edge of the outer region, of the forming tool is thereby pressed into the blank. Thereby, the groove and / or the trough, in particular in a single Verfahrungsschritt, are formed in the blank.

Furthermore, the tool axes of the forming tools can be angled relative to each other so that grooves can be formed spirally around the axis of the blank. In particular, the tool axes of the

Forming tools to each other to be arranged in parallel axis planes, but in the axial plane to each other angled tool axes. The tool axes of the forming tools may also be inclined to the axis of the blank or of the drilling tool. This can be a

Bevel angle of the groove and / or the trough of the drilling tool can be adjusted. In order to form supporting cross-sections, in particular grooves and / or depressions, it is possible to arrange the forming tools either in such a way that the forming tools come closer together to reduce the load-bearing cross-section, or to make the forming tools such that between an initial state the forming tools engage the blank until a final state where the forming tools are disengaged, the forming tools have a varying radius. In the latter case, it is important that a state of initial engagement of the forming tool with the blank is the same for each blank. As a result, the forming tool is merely a circle-shaped around the

Tool axis be designed to run.

The peripheral region, in particular the forming edge, can run in a spiral around the tool axis. In particular, the peripheral area,

in particular the peripheral edge, have an increase, the one on the

Drilling tool forms a contrary depression. In this case, the trough may be formed as a recess introduced by the increase of the forming tool in the production. The elevation may take the form of an accumulation of material on an outer area, in particular a starting area and / or an end area, of the

Forming tool be formed. The increase can increase steadily or suddenly. The elevation may extend radially and / or axially to the tool axis. In particular, by a suitable design of the elevation, a recess formed as a depression in the groove can be formed, which is introduced into the rake surface and / or the transport surface. It can also be adjusted by how far the trough in the rake face and how far the trough is placed in the transport surface. Likewise, thereby, the axial extent of the trough may be formed only in the transport surface.

Furthermore, the subject of the invention is a device for producing the drilling tool. The device is designed for carrying out a method for producing a drilling tool. That at least one

Forming tool has at least one increase. Brief description of the drawings

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawings, the description and the claims contain numerous features

Combination. The person skilled in the art will expediently also consider these features individually and combine them into meaningful further combinations.

This shows

1 is a perspective view of a hand tool with a drilling tool,

Fig. 2 is a side view of a first embodiment of a

drilling tool according to the invention,

Fig. 3a - b shows a detail and a frontal plan view of the

Drilling tool of Fig. 2,

4a-b a detail of and a frontal plan view of the

drilling tool

5 is a cross-sectional view a-a of the drilling tool of FIG. 3,

Fig. 6 is a cross-sectional view taken along the axis a of a

Embodiment of a drilling tool and

Fig. 7 is a side view of the inventive forming tool.

In the following figures, the same components are provided with the same reference numerals.

The following figures each relate to a drilling tool, in particular a metal drilling tool, in particular for receiving the drilling tool in a receiving device of a machine tool, preferably a hand tool, with a rotary and / or translational working movement on a workpiece to be machined. This is a

translational feed introduced into the workpiece by the operator of the power tool, a force on the power tool,

especially the hand tool housing, applies. The

Drilling tool is suitable for machining, in particular for drilling metals. However, the drilling tool according to the invention is not only designed for drilling metals, but can also be used for machining other materials that appear appropriate to a person skilled in the art, such as wood, plastic or a composite.

1 shows a perspective view of a handheld power tool 101 with a drilling tool 1 clamped in the receiving device 105. The handheld power tool 101 has a handheld power tool housing 103 with at least one grip area 109 for grasping with at least one hand of a user. The receiving device 105 in this

Embodiment has three jaws 107, of which only two jaws 107 are shown. The jaws 107 tension the

Drill 1 radially in the receiving device 105 a.

The side view of the drilling tool 1 according to FIG. 2 shows a

Receiving portion 3 of the drilling tool 1, which for receiving in a

Receiving device 105 of a power tool 101 is provided and a work area 5, which is provided for machining a workpiece. The drilling tool 1 is at least substantially cylindrical. The receiving area 3 has a circular cross-sectional area. In an alternative embodiment, the cross-sectional area may be a

have polygonal cross-section. The receiving area 3 extends axially from a clamping end of the drilling tool 1 to the working area 5 and adjoins the working area 5. Alternatively or additionally, the

Receptacle 3 form-fitting means, such as depressions and / or survey (not shown), which, for an improved, in particular positive connection with the holding device 105 of the

Hand tool 101 may be provided. The to the Recording area 3 subsequent work area 5 also has a

Forehead area and two grooves 7 on.

The two grooves 7 are formed at least substantially spiral. The two grooves 7 extend axially about an axis a of the drilling tool 1 around and open in the end region 9 of the working area 5 of the

1. The two grooves 7 extend in the direction of the end region 9 transversely to the axis a of the drilling tool 1. In particular, the preferably radial extension of the two grooves 7 in the direction of the end region 9 can decrease at least partially continuously and / or at least partially abruptly. The radial extent of the grooves 7 may further form a radius of a supporting cross-section 11 of the drilling tool 1, which is formed in a radially extending to the axis a of the drilling tool level. This supporting cross-section 11 may be formed in particular circular. In this case, the supporting cross section 11 may be circular, in particular as a circle, with a center about the axis a of the drilling tool 1. The supporting cross-section 11 may have a radius which may be formed continuously decreasing along the axis a with decreasing distance to the end region 9. In an alternative embodiment, the radial extent of the at least one groove 9, in particular of the two grooves 9, run at least substantially parallel to the axis a of the drilling tool 1.

The two grooves 7 are separated in the circumferential direction of, in particular two, webs 13. Thus, the webs 13 extend parallel to the grooves 7 and are formed spirally. A peripheral region 15 of the webs 13 limits the radial extension of the drilling tool 1. The peripheral region 15 of the webs 13 further has a first peripheral surface 17, which is characterized by a first radial extent or a first radius. Furthermore, the web 13 has a second peripheral surface 19, which is characterized radially with a second radial extent or a second radius. The second

Peripheral surface 19 is radially from the first peripheral surface 17.

Furthermore, the second circumferential surface 19 is smaller than the first peripheral surface 17. The second peripheral surface 19 limits the radial extent of the second portion 5 of the drilling tool 1. The second peripheral surface 19 is to provided a friction surface and accordingly a frictional effect that increases when drilling in a wellbore with increasing drilling depth to minimize.

In each case, a groove 7 in this case has a groove surface 21, 23, which can be divided into two groove surfaces 21, 23. A first groove surface 21 is axially through a

Main cutting edge 25 of the end portion 9 limited. The first groove surface 21 is formed as a rake surface 21 of the main cutting edge 25. A second groove surface 23 is bounded by an end face 27 of the end region 9. The second

Slot surface 23 is formed as a transport surface 23. The first groove surface 21 and the second groove surface 23 can merge into each other. The first groove surface

21 and the second groove surface 23 may be separated from each other by an imaginary line in the at least one groove 9 or at least one groove 31 which extends through the, in particular minimum, radial extent of the groove or trough along the groove or trough of the drilling tool , The at least one end face 27 is an open surface 27 of the main cutting edge

25 of the end portion 9 is formed.

The end region 9 essentially has two end faces 27. The two end faces 27 are separated from each other by a transverse cutting element 29. Both end faces 27 form between a rake face 21 of the groove 7 a

Main cutting edge 25, which is formed as a main cutting element 25. The front cutting area 25 delimits the axial extent of the drilling tool 1, in particular of the working area 5. The at least one main cutting element 25 is formed so as to protrude axially that the end faces 27 are angled to the respective main cutting edges 25 and in the direction of

Receiving area 3 run. Furthermore, at least one of the grooves 7 is adjacent to the forehead area

9 at least one trough 31 on. The trough 31 is elongated and extends along the axis a of the working area 5 of the drilling tool 1. The trough 31 extends at least substantially parallel to the axis a of the drilling tool 1. The trough 31 is arranged in a central region of the drilling tool 1. The trough 31 is at least partially in the first groove surface 21 and the rake face 21 of the groove 7 is arranged. The trough 31 is at least partially disposed in the second groove surface 23 or the transport surface 23 of the groove 7. In an alternative embodiment, the trough 31 is formed exclusively in a transport surface 23 of the groove 7, whereby a corresponding

increased transport volume is generated. In particular, the trough can extend to a peripheral region 15. As a result, the main cutting edge 25 or the main cutting element 25 can run homogeneously, in particular in a straight line and / or in a curved manner, without being changed by the inserted depression 31. Thus, the processed by the main cutting edge 25 Bohrmehl can be stored in an increased transport volume before it is conveyed out through the groove 7 from the wellbore. Likewise, a radial extension or the supporting cross section 11 of the at least one groove 7 adjacent to the end region 9 can be reduced axially relative to the end region. This makes it possible to minimize a radial extension of the transverse cutting element 29, in particular a transverse cutting edge 29.

The trough 31 is formed at least substantially rectangular. One, in particular axial, main extension of the trough 31 is formed with respect to a transverse extent by up to 300%. In this case, the transverse extent transverse, in particular at least substantially orthogonal, to

Main extension run. The transverse extent of the trough 31 extends over the diameter of the drilling tool 1 by up to 40%, such as 30% or 15%. The transverse extent of the trough 31 extends over the diameter of the drilling tool 1 by up to 55%, in particular by up to 40%, such as 25% or 20%. The maximum radial

Extension of the trough 31 advantageously extends over the maximum radial extension of the drilling tool 1 by up to 30%, for example 25% or 15%. FIG. 3 a shows a section of the drilling tool 1 with the end region 9 and the depression 31, as already described in FIG. 2. It can clearly be seen how the depression 31 extends along the axis a of the drilling tool 1 and is provided in a central region to the axis a of the drilling tool 1. Likewise, the trained as an open space face 9 can be seen, in particular, the trough 31 opens. Clearly show are the two end faces 27 of the end portion 9 and the transversely to the main cutting elements 25 extending transverse cutting elements 29 which separate the two end faces 27 from each other. Likewise, the two opposing grooves 7, which are to each other, in particular

symmetrical, lost, to see. The two at least substantially rectilinear main cutting elements 25 and main cutting edges 25, which are at least substantially formed by the respective rake face 21 of the groove 7 and the respective formed as an open surface 27 end face 27 of the end portion 9. Furthermore, in each case a trough 31 is shown, which is in each case formed in a groove 7 and limits the extension of the cross-cutting element 25. In an alternative embodiment, at least one groove 9 may also have a plurality of wells 31. In an alternative embodiment, the end region 9 can also be formed without the transverse cutting element 25. The troughs 31 thereby extend substantially axially relative to the axis a of the drilling tool 1. The troughs 31 thus reduce the end faces 27 of the end region 9. Furthermore, FIG. 3b shows the supporting cross section 11 from FIG. 1, which in this embodiment is formed circularly about the axis a of the drilling tool 1. Here, the load-bearing cross section 11 of two opposing grooves 7 is formed. The radial extent of the supporting cross section 11 is reduced in the feed direction of the drilling tool 1 by the troughs 31.

FIG. 4 a shows a section of the drilling tool 1. The working area 5 is formed at least essentially analogously to the working area 5 of FIG. 2. In contrast to the first embodiment, the trough 31 of the second embodiment is at least substantially in the

Transport surface 23 is formed. The trough 31 may be formed exclusively in the transport surface 23. The radial extension of the trough 31 may be formed at least substantially larger than the axial extension trough. The trough 31 limits the web 13, in particular the peripheral surface 17, 19 of the web thirteenth 4b shows a frontal plan view of the drilling tool 1 from FIG. 4a. The end region 9 is formed at least essentially analogously to the end region 9 of FIG. 2. As already shown in Fig. 4a, the trough 31 is at least substantially formed in the transport surface 23 and extends to the

Web 13, in particular to the peripheral surface 17, 19 of the web thirteenth

FIG. 5 shows a cross-sectional view a-a from FIG. 3a and additionally two forming tools 71, in particular two rollers 71, preferably

Schmiederollen, each of the grooves 7 reshape, in particular rolling or forging. The circular load-bearing cross-section 11, the center of which is the axis a of the drilling tool 1, can be seen. The two forming tools 71 engage in the workpiece in such a way that the workpiece or the blank is deformed, in particular solidly deformed. The wedge-shaped

Forming tools 71 may form a groove 7 whose groove surfaces 21, 23, in particular the first groove surface 21 and the second groove surface 23, at an angle α in a range of 40 ° to 155 °, in particular from 45 ° to 150 °, preferably from 50 ° to 145 °, preferably from 55 ° to 140 °, are formed to each other. The first groove surface 21 and the second groove surface 23 may have a radius of up to 0.5 mm, in particular up to 1 mm, preferably up to 1.5 mm, preferably up to 2 mm, particularly preferably up to 2.5 mm, be connected to each other.

FIG. 6 shows a cross section along the axis a of the drilling tool 1 from FIG. 2. A projection of the supporting cross section 11 of FIG

It can be seen above all that the minimum radial extension of the at least one groove 7 or the supporting cross section 11 tapers continuously towards the end region 9. The groove 7 can not be seen in FIG. 6, but is shown as a projection of a region extending radially to the supporting cross section 11.

FIG. 7 shows a cross-sectional view of the forming tool 71. The forming tool 71 extends along a circular section and axially to a tool axis b of the forming tool 71. The forming tool 71 is at least substantially hollow cylindrical. In a Alternatively, the forming tool 71 may be at least substantially cylindrical. The forming tool 71 has an outer area 73 and an outer area 73 opposite

Interior 75 on. The outer region 73 may be formed as an outer surface. The inner region 75 may be formed as an inner surface. The

Forming tool is limited in the circumferential direction 77, 78 by side surfaces 79.

Holes 81, which are provided to connect the forming tool 71 to a carrier (not shown), may be introduced into the forming tool 71 parallel to the tool axis b.

The outer region 73 of the forming tool 71 has a forming edge 83. The forming edge 83 is provided to form a groove 7 and / or a recess 31 in a blank or a drilling tool 71. The forming edge 83 extends at least substantially helically around the tool axis b. The radial extension of the forming edge 83 to the tool axis b may increase in the circumferential direction 77, 78. In particular, the forming edge 83 of the outer region 73 may be formed such that the radial extent in the circumferential direction 77, 78 increases from a first position of the forming tool to a second position of the forming tool 71. In particular, the radial extension of the forming edge 83 extends continuously, for example, from a position I via a position II and a position III to a position IV. In an alternative embodiment, the radial extent of the forming edge 83 can be constant from a position I to a position IV or increase or decrease abruptly. Preferably, the forming edge 83 is provided with an increase 85, which is provided for example at the position V. The increase 85 may be provided to the

Drill 1 to form a contrast to the increase 85 recess. The recess in the drilling tool is a trough in a groove of the

Drilling tool formed.

The general method of the deforming method, in particular the profile rolling, of drilling tools 1 is already generally known to a person skilled in the art and is therefore not described in detail. For a possible construction of a device, reference is made to EP 0 792 705 A2.

Claims

claims

1. drilling tool, in particular metal drilling tool, with at least one, in particular helically, about an axis (a) of the drilling tool (1) extending groove (7) and with a front region (9) having at least one end face (27) and at least one main cutting element (25 ) formed between at least one rake face (21) of the groove (7) and the at least one end face (27), the at least one groove (7) being adjacent, in particular adjacent, to the face region (9),

characterized in that the trough (31) by a

Forming process is formed in the at least one groove (7).

2. Drilling tool according to claim 1, characterized in that the trough (31), in particular a main extension of the trough (31), at least substantially along, in particular parallel to, the axis (a) of the

Drilling tool (1) is formed.

3. Drilling tool according to one of the preceding claims, characterized

in that the trough (31), in particular the main extension of the trough (31), is formed at an angle to the axis (a) of the drilling tool (1).

4. Drilling tool according to one of the preceding claims, characterized

characterized in that the trough (31) at least partially adjacent to at least one end face (27).

5. Drilling tool according to one of the preceding claims, characterized

characterized in that the radial extent of the groove (7) with increasing distance from the end region (9) is formed continuously increasing or continuously or stepwise.

6. Drilling tool according to one of the preceding claims, characterized in that the minimum radial extent of the trough (31) with increasing distance from the end region (9) is formed continuously and / or continuously or stepwise increasingly.

7. Drilling tool according to one of the preceding claims, characterized

characterized in that the minimum radial extension of the trough (31) relative to the minimum radial extent of the groove (7) by up to 40%, in particular by up to 30%, preferably by up to 20%, preferably by up to 10%, more preferably by up to 5%.

8. Drilling tool according to one of the preceding claims, characterized

characterized in that the trough (31) extends axially with respect to the maximum axial extent of the drilling tool (1) of up to 10%, in particular up to 8%, preferably up to 6%, preferably up to 5%.

9. Drilling tool according to one of the preceding claims, characterized

characterized in that the radial extension of the trough (31) up to 50%, in particular up to 40%, preferably up to 30%, preferably up to 20%, particularly preferably up to 10%, of the maximum radial extent of the drilling tool (1) equivalent.

10. Drilling tool according to one of the preceding claims, characterized

characterized in that the trough (31), in particular at least in

Essentially, in a transport surface (23) of the groove (7) is formed.

11. A method for producing a drilling tool (1) according to one of

preceding claims, characterized in that the trough (31) is formed by a forming process in the at least one groove (7).

12. An apparatus for carrying out a method according to claim 11, characterized in that at least one forming tool has an elevation (85).