Cutting tool with flank structure for coolant control

Abstract

A rotary cutting tool with a geometrically defined cutting edge, namely a drilling or milling tool, with a grinding for forming a tool cutting edge (30) which lies in the area of ​​influence of a cooling lubricant (CLS) flow, with at least one structure (50; 150-1 to 150-3; 250-1 to 250-3) of any desired depth and width located within the flank (28-1, 28-2; 128) of the cutting tool (20; 120; 22), which structure is designed in such a way that the CLS flow can be influenced by it, characterized in that the structure is designed as a depression in such a way that the CLS can be directed at least in the direction of a highly loaded region (BS) of the tool cutting edge (30; 130, 135; 230, 235), wherein the depression (50; 50-1, 50-2; 50-1, 50-2, 50-3) is formed by a shallow groove which begins near the drill or milling cutter centre and extends to the outer surface (38) of the secondary or peripheral cutting edge chamfer, where it becomes the secondary orCircumferential cutting edge clearance surface (40) opens.

Description

[0001] The invention relates to a rotary-driven cutting tool with a geometrically defined cutting edge, namely a drilling or milling tool, according to the preamble of patent claim 1. The invention relates in particular to a drilling or milling tool which is specially tailored for machining high-strength and tough, i.e. difficult-to-machine, materials, such as corrosion- and temperature-resistant nickel-based alloys, such as an alloy with the German material number 2.4668.

[0002] Various tools are known which are equipped with geometric structures in the area of ​​their grinding, with which the supply of coolant / lubricant, hereinafter abbreviated as KSS, to highly stressed areas is intended to improve.

[0003] According to GB 2 483 475 A, the surface is provided with a pattern of micro-recesses by laser treatment in which cooling lubricant is to be retained.

[0004] Document DE 101 44 241 A1 discloses a drilling tool in which such a structure is present in the form of groove-shaped branch channels. These branch channels extend from the opening of internal cooling channels and lead essentially radially outward to several chip grooves, behind which additional reaming edges are located. Furthermore, the branch channels are located in a surface that is axially set back from the drilling edge. The tool cutting edge is therefore not within the influence of a coolant flow, which therefore cannot contribute to stabilizing the tool cutting edge.

[0005] A generic tool is described in document WO 00 / 03 825 A1. The cutting tool has a geometrically defined cutting edge, with a ground surface to form a tool cutting edge that lies in the influence area of ​​a cooling lubricant (CLS) flow. Within the flank face, a recessed area is formed, which is bordered by the tool cutting edge and a raised area. The recessed area is designed as a type of trough / reservoir, through whose topography coolant / lubricant is guided in the direction of rotation towards the tool cutting edge. The coolant / lubricant is intended to leave the reservoir formed by the recessed area through a chip-forming notch in the area of ​​the drill center, thereby cooling the chisel cutting edge.

[0006] The service life of a cutting tool is generally determined by the wear of the main cutting edges and the cutting edges, which results from the wear mechanisms of abrasion, adhesion, surface disruption, and tribochemical reaction during machining. Particularly when machining high-strength, corrosion- and temperature-resistant nickel-based alloys, the tools are subject to high thermomechanical loads and the resulting severe wear, which is due to the properties of the corresponding alloys. Among other things, these alloys have relatively low thermal conductivity, so that the workpiece material—i.e., the workpiece and the resulting chips—can only partially dissipate the heat generated during the machining process.This is particularly problematic when drilling, because geometrically defined cutting edges are used here, which on the one hand are used deep within a workpiece and on the other hand must remain stable over a long drilling path so that relatively tight shape and surface tolerances are maintained.

[0007] It is generally known that, for tools with geometrically defined cutting edges, the service life of the tool can be extended until the critical wear point is reached by providing the flank with a recess at a predetermined distance from the cutting edge. This approach is described in documents DE-PS 877 531, DE 43 19 505 A1, and DE 10 2006 020 613 A1 and scientifically investigated in the dissertation "New cutting edge geometries for improving tool performance during hard turning" (author: M.Sc. Dipl.-Ing. (FH) Roland Meyer; Faculty of Mechanical Engineering at the Gottfried Wilhelm Leibniz University of Hanover, 2011).

[0008] It has been demonstrated that this approach can also be successfully applied to drilling tools. Results of tool life tests with internally cooled solid carbide (VHM) drilling tools are described in the article "Drilling of Inconel 718 with Geometry-modified Twist Drills" (published in Procedia CIRP 24 (2014), pages 49 to 55; with the authors Nicolas Beer, Ekrem Özkaya, and Dirk Biermann). It was shown that by incorporating a shallow groove into the main flank surface, running at a short parallel distance to the main cutting edge, an improvement in the tool life and working accuracy could be achieved.

[0009] The invention is based on the object of developing the generic cutting tool, such as a generic drilling or milling tool, in such a way that it is characterized by a further improved service life while maintaining the machining accuracy or can be used with improved productivity for a given tool life.

[0010] This problem is solved by the features of patent claim 1.

[0011] According to the invention, a shallow structure introduced into the flank surface is used to impart a specific flow direction to the coolant present in this area, thus influencing the coolant flow in such a way that a type of directed forced flow is created and the coolant is directed at least toward a highly stressed area of ​​the tool cutting edge. Due to the specific guidance of the coolant, the coolant flow is directed in the area of ​​the secondary or peripheral cutting edge chamfer, thereby making it possible to protect the main cutting edge and the cutting edge corner particularly effectively from overheating.

[0012] While up to now the cooling lubricant has reached the area of ​​the main cutting edge more or less uncontrolled, the invention creates a forced flow for the cooling lubricant through a special geometric design and guidance of the structure incorporated into the main flank surface. This makes it possible to cool the highly stressed areas of the cutting edge, such as the main cutting edge of a drilling tool or the face cutting edge of a milling tool, more effectively with minimal intervention in the grinding geometry of the tool, even with a constant total volume flow of the cooling lubricant supplied through the internal cooling lubricant channels, by largely containing the uncontrolled outflow of cooling lubricant. All common cooling lubricants can be used as cooling lubricants, including all emulsions and oils, but also cooling lubricants for minimum quantity lubrication and for cryogenic process cooling with e.g. LN2 or CO2.The invention is generally applicable to all known workpiece and tool materials. However, it offers particularly significant advantages when it comes to economically machining difficult-to-machine materials.

[0013] Advantageous further training is the subject of the subclaims.

[0014] The invention can be applied to a wide variety of cutting tools, particularly to all rotary cutting tools such as milling tools, reaming tools, or thread-cutting tools. It has been shown that the inventive design of the flank face can be used particularly effectively to improve tool life when the tool is designed as a drilling tool with an internal channel system for the coolant supply and with a point grind with a main cutting edge, a secondary cutting edge, a guide chamfer, a main and secondary flank face, and a cutting edge corner.

[0015] If at least one structure is incorporated into the flank face in such a way that it also extends to adjacent tool surfaces in the flank face, such as - in the case of a drilling tool - the guide land, secondary flank face / back or the thinning, the forced flow directed into the highly stressed areas of the cutting edge is assigned a discharge line with which the coolant flow can be additionally influenced. The discharge line stabilizing the coolant flow can be variably designed and arranged. The selection is made depending on the respective process conditions, such as material pairing, cutting speed, type of grinding and coolant, and flow velocity of the coolant. The optimal shape in each case can also be determined empirically or mathematically.

[0016] If the recess is located within the flank area in the area between the cooling channel outlet and the tool cutting edge, in particular the main cutting edge, and is executed entirely or in sections over this distance, a relatively large area on the front surface of the tool can be used to control the coolant flow.

[0017] If one or more structures within the relevant flank surface, such as the main flank surface of a drilling tool or the flank surface of the face cutting edge of a milling tool, follow the tool cutting edge, in particular the main cutting edge or face cutting edge, entirely or in sections with a constant or variable distance, additional advantages arise with regard to the improvement in the tool life of the main cutting edge, in particular if the distance is in the range of 50 to 300 µm, preferably in the range of 100 to 150 µm.

[0018] If, according to claim 8, several structures (50A to 50E) are used in combination or combined to form one structure, cooling lubricant flow patterns can be superimposed in a particularly advantageous manner.

[0019] It has been shown that even with extremely flat structures according to claim 9, it is possible to stably form and stabilize the coolant flow towards particularly stressed areas of the cutting edge in question.

[0020] The dimensions of the structure or the depression in the flank can be varied within wide limits. It is also not necessary for the depression to have a uniform depth across the entire area of ​​its structure. Rather, it can be designed in a relief-like manner, with the depth of the depression being variable in order to exert a controlling influence on the coolant flow. It has been shown that depth dimensions according to claim 9 in the range between 20 and 350 µm are already sufficient to establish and stabilize a sufficiently stable and effective coolant flow with a sufficiently positive influence on the cooling of highly stressed tool areas in order to effectively increase the tool service life. Structures with such small depth dimensions can be produced particularly economically and do not noticeably weaken the tool.

[0021] The design according to claim 10 has the advantage that only minimal intervention in the relevant free surface of the tool is required.

[0022] The development of claim 12 makes it possible to influence the forced flow of coolant with a further minimal intervention in the flank area. The width and depth of the embroidery channel groove can also vary within wide limits, although it has been shown that depths in the range of 20 to 350 µm are sufficient to exert a controlling influence on the forced flow directed towards and along the cutting edge.

[0023] If - according to claim 13 - the branch channel groove extending from the mouth opening runs essentially radially to the center of the cutting tool designed as a drill, the particularly low cutting speed in this area can be utilized to supply the coolant forced flow according to the invention.

[0024] If - according to claim 14 - several branch channel grooves are provided, which are essentially star-shaped and extend from the mouth opening to the flat groove, the coolant flow directed to the particularly highly stressed sections of the tool can be additionally fed. In this case, it is advantageous to coordinate the branch channel grooves geometrically, i.e., in terms of width, depth, and direction, so that the partial flows effectively complement each other at the crucial points.

[0025] A borderline case of the variant according to claim 14 is the further development of claim 15. The depression in the design as a flat, circular segment-like removal of the free surface can be effectively used to form a forced flow of the cooling lubricant if the depth relief is suitably selected.

[0026] As already mentioned above, it has been shown that even very shallow removal patterns in the flank area, less than 1 / 10 of a millimeter, are sufficient to significantly improve the cooling of particularly highly stressed areas of the cutting edge and to increase the service life of the cutting tool, particularly the drilling or milling tool, and its productivity. Such removal patterns can be achieved particularly precisely, easily, and economically using laser processing according to claim 16. The particular advantage is that any material can be processed quickly and precisely.

[0027] Several embodiments of the invention are explained in more detail below with reference to schematic drawings. They show: Fig. 1 to 15 schematic, perspective top views of drilling tools, the flanks of which are each equipped with a structure for influencing the coolant flow, whereby only the Fig. 6 to 9 and 11 to 14 show structures in the claimed embodiment; Fig. 16 an enlarged sectional view according to “XVI-XVI” in Fig. 15, which is essentially identical to the sectional view of the recess according to Fig. 12 is; Fig. 17 in an enlarged view the detail “XVII” in Fig. 16; Fig. 18 a schematic perspective view of a tool according to the invention in the form of a milling tool; and Fig. 19 one of the Fig. 18 corresponding view of a variant of the milling tool according to Fig. 18.

[0028] The invention is described below using exemplary embodiments in which the cutting tool is formed by a drilling tool. However, it should be emphasized that the inventive concept of flank design can equally be advantageously applied to other cutting tools, in particular rotary-driven tools with geometrically defined cutting edges, such as milling, reaming, or thread-cutting tools, by designing the flank associated with the tool cutting edge as described in the patent claims and using it to influence the coolant flow.

[0029] In the Fig. In Figures 1 to 15, reference numeral 20 depicts a two-flute twist drill with internal cooling channels 22, which are located point-symmetrically to the drill axis 24 in the drill lands 26 and open into the respective flanks 28. 38 denotes the outer surface of the secondary cutting edge chamfer, and 40 the secondary flank of the drilling tool. A dash-dotted line indicates the nominal diameter of the drilling tool or the bore.

[0030] The chip flutes are designated by reference numeral 34. The contour of the opening 22M of the cooling channels 22, which results from the cooling channel cross-section and the position and shape of the secondary flank 38-2, resembles an oval in the embodiment shown. However, both the cross-section of the cooling channel and the design of the grinding are by no means intended to be limited to such a design.

[0031] The tools shown have a special point grinding in the form of a cross grinding with two main flanks located one behind the other, one as shown in the illustrations in the Fig. 16 and Fig. 17 removable primary flank 28-1 (with a clearance angle α1) and a secondary flank 28-2 (with a larger clearance angle α2), and an adjoining thinning 32, so that a transverse cutting edge is reduced to a minimum length by the secondary flank 28-2 and the thinning 32. Thus, the main cutting edge 30 extends from a cutting edge corner 36 via a concave cutting edge section 30-1 in the region of the chip groove via a convex cutting edge center section 30-2 far into the drill core. However, it should already be emphasized at this point that the invention is applicable to any drilling tool with any grinding.

[0032] The schematically illustrated drilling tool consists, for example, of a hard material, such as solid carbide (SHM) or a cermet material. However, it can also be made of any other material, such as HSS or HSSE, that guarantees the required service life. The material is preferably selected so that it is suitable for machining difficult-to-machine materials, such as corrosion- and temperature-resistant nickel-based alloys. However, the invention is not limited to this field of application.

[0033] The special feature of the drilling tool is that the flank surface is equipped with a special, machined structure, which is highlighted in gray in the figures. For the sake of simplicity, the design of the flank surface is only shown and described in the area of ​​one drill bit. Naturally, both drill bits are machined or ground point-symmetrically to the drill bit axis 24.

[0034] The figures show that within the flanks 28-1, 28-2 of the drilling tool there is a structure 50 of any desired depth and width, which is designed in such a way that the coolant flow can be influenced and the coolant - as indicated by the arrows 60 - can be directed at least in the direction of a highly loaded area BS of the tool cutting edge 30. In the example according to Fig. 1, the structure 50 is formed by an oval-shaped shallow depression which extends towards the cutting edge 36. The depth T50 is - as schematically shown in Fig. 16 and Fig. 17, to which reference is already made and which, for all embodiments shown, illustrates in more detail the position and dimensions of the structure 50 incorporated into the main flank 28—in the range from 20 to 350 µm. Thus, the structure 50 directs the coolant flow—as indicated by arrow 60—in the direction of the cutting edge corner 36.

[0035] The structure 50 is incorporated into the main flank 28, for example, by laser machining, but it can also be introduced in any other known manner, for example, by grinding. The depth T50 can also be kept variable over the length of the groove 50.

[0036] In the modified example according to Fig. 2, three structures 50A, 50B, 50C are arranged within the flank area such that they are located in the area between the cooling channel outlet 22M and the main cutting edge 30. Deviating from the embodiment according to Fig. 1, they extend not only in sections, but across this entire section. The directed coolant flows, which can also be referred to as forced flows, are again indicated by arrows 60.

[0037] For the drilling tool according to Fig. 3, two structures 50D and 50E follow the main cutting edge 30 within the flank 28-1, either entirely or in sections, at a constant distance A. However, this distance A can also be variable. In the embodiment shown, the distance A is in the range of 50 to 300 µm, preferably in the range of 100 to 150 µm. Thus, in this embodiment, several structures 50 and 50E are used in combination.

[0038] The example according to Fig. 4 has the special feature that several structures, ie the structure 50 of the Fig. 1 and the structure 50E of the Fig. 3 or the structure 50B of the Fig. 2 and the structure 50D of the Fig. 3 are combined to form a structure 50G or 50F.

[0039] The structures in the drilling tool according to Fig. 5 are similar to the drilling tool according to Fig. 4. However, the structure designated 50G* is incorporated into the flank surface 28-1, 28-2 in such a way that it also extends to the secondary flank surface or to the back 40, thereby providing a drainage path for the directed coolant flow. Alternatively, the structure can also extend into other tool surfaces adjacent to the flank surface 28-1, 28-2, such as the guide bevel 38 or the point thinning 32.

[0040] Fig. Figure 6 shows a first embodiment of the invention with a large-area structure in which several of the structures described above are combined to direct the coolant flow in a controlled manner. In this case, a relief-like design of the structure can be used as an additional means, i.e., a structure with additionally incorporated channels or grooves (not shown).

[0041] In the following, the Fig. Figures 7 to 9 and 11 to 14 show further variants of the tool according to the invention, in which slightly modified structures are used. In these embodiments, the coolant flow is again specifically directed by a structure in the flank area. Furthermore, the structure becomes part of a channel arrangement with forced flow.

[0042] One can see in the embodiment according to Fig. 7, that the structure introduced into the main flank is designed as a shallow depression 50 extending at least partially along the main cutting edge 30. This depression 50 is further designed in such a way that it becomes part of a coolant / lubricant channel arrangement in which coolant / lubricant (KSS) emerging from the orifice 22M and, among other things - as schematically indicated by the arrows KSS - also flowing against the cutting direction in the direction of the main cutting edge, is brought into a forced flow indicated by arrows 60-1 to 60-4, which encompasses at least a selected, highly loaded area of ​​the cutting edge - here the area BS indicated by a dash-dotted line. In the embodiment of the Fig. 1, this particularly highly stressed cutting edge area BS is the transition between the cutting edge sections 30-1 and 30-2. However, this area can vary from tool to tool depending on the grinding geometry and the process parameters.

[0043] In the design of the Fig. 7, the recess 50 is formed by a shallow groove that begins near the drill center and extends to the outer surface 38 of the secondary cutting edge land, where it opens - as indicated by the arrow 60-4 - to the secondary flank 40. The recess 50 is accordingly designed such that it forms a flow path for the forced flow 60-1 to 60-4, represented by the flow arrow 60-4, at least in the region of a radially outer section of the recess 50.

[0044] This can best be seen from the illustrations of the Fig. 16 and Fig. 17, to which reference is again made and which shows in more detail, by way of example for all embodiments shown, the position and dimensions of the depression 50 machined into the main flank 28, that the depression is located only in the area of ​​the primary flank 28-1, specifically at a small distance A from the cutting edge 30. This distance A should not be less than 50 µm and should preferably be in the range between 50 and 350 µm, preferably in the range between 100 and 200 µm, in order to be able to effectively reduce the thermal load on the tool at the selected locations. The width B50 of the shallow groove 50 forming the depression can vary within wide limits and is, for example, in the range between 100 and 500 µm. The depth T50 of the groove is between 30 and 300 µm. The depth T50 of the groove 50 is - as the Fig. 10 can best be taken - very small, but at the same time it is in the order of magnitude of the small gap 70 that occurs during drilling between the workpiece WS and the primary clearance surface 28-1, so that the shallow groove can be used to effectively build up the forced flow for the coolant.

[0045] The groove 50 is machined into the main flank 28, for example, by laser machining, as in the previously described variants, but it can also be introduced in any other known manner, for example, by grinding. The depth T50 can also be kept variable over the length of the groove 50.

[0046] Fig. 8 shows a modification of the Fig. 7. Here, the recess in the area of ​​the drill core is omitted. Instead, a groove section 50-2, which is closest to the most highly stressed cutting edge area, is supplied with coolant via a recess section 50-1 extending from the mouth opening 22M, so that the forced flow 60-1 to 60-4 is stabilized. Again, the recess 50 is designed such that it forms a flow path for the forced flow 60-1 to 60-4 in the area of ​​a radially outer section of the recess 50, represented by the flow arrow 60-4.

[0047] The design variant according to Fig. 9 differs from the embodiment according to Fig. 7 only in that the groove 50 is again guided to the vicinity of the drill center, where it is connected to the mouth opening 22M via a further recessed section 50-3.

[0048] The example of Fig. 10 corresponds essentially to the embodiment of the Fig. 7, with the difference that the recess 50, in the design as a shallow groove, which begins near the drill center, is guided to a point near the outer surface of the secondary cutting edge, where it merges into a shallow channel 50A, which runs over the main flank 38-1 and 38-2 to the chip groove 34 or to the point thinning 32. Consequently, the recess 50 is again designed such that it forms an outlet, represented by the flow arrow 60-4, into the channel 50A for the forced flow 60-1 to 60-4 in the region of a radially outer section of the recess 50.

[0049] With reference to the Fig. 11 to 14 describe further claimed variants which, in addition to the advantages already described, are characterized by the special feature that the effective cooling of highly stressed cutting areas is combined with wear protection. In these variants, the recess 50 towards the main cutting edge 30 is delimited by an edge VGK running at a small parallel distance A* to the main cutting edge 30, so that a recess of the flank is produced at a predetermined distance from the cutting edge. The recess is otherwise again designed in such a way that it forces the coolant emerging from the outlet opening 22M into a forced flow directed along the edge VGK to the cutting edge corner 36 and past it, which is indicated by the arrows 60-1 to 60-4. The dimensions of the recess are the same as those described above for the variants of the Fig. 7 to 10 things said, so that repetitions can be avoided.

[0050] In the embodiments of the Fig. 11 to 14, the flow path indicated by the arrow 60-4 is opened to the secondary free surface 40. In the unstressed variant of the Fig. 15 - similar to the variant according to Fig. 10 - the coolant flow is conducted via a recessed section 50A in the flank 3 to the chip groove 34 or to the point thinning 32.

[0051] In the embodiments according to the Fig. 12 and Fig. 13, the flat groove 50 is connected to at least one branch channel groove 50-3 to 50-5 introduced into the main free surface 28-1, 28-2, each of which extends from the mouth opening 22M. In this case, a branch channel groove 50-3 extending from the mouth opening 22M can extend substantially radially to the center of the drill, similar to the variant of the Fig. 10.

[0052] In the design of the Fig. 13, several branch channel grooves 50-3 to 50-5 are guided essentially in a star shape from the mouth opening 22M to the flat groove 50. The orientation and design of the recesses 50-1 to 50-5 again contribute to the development and stabilization of a forced flow, indicated by the arrows 60-1 to 60-4, to or along the particularly highly stressed cutting areas.

[0053] In the design of the Fig. 14 the recess is - similar to the variant according to Fig. 6 - is formed by a flat, circular segment-like removal of the flank surface 28-1, 28-2, wherein the removal is guided up to the outer surface 38 of the guide chamfer. In general, but especially in the variant of the Fig. 14, the formation and guidance of the coolant flow for cooling the highly stressed cutting areas can be further influenced by forming the shallow recess 50 or structure in the manner of a relief with a depth T50 that is variable at least in some areas. In this way, partial flows in the area of ​​the recess 50 can be optimally combined.

[0054] Further embodiments are described below. Those elements that correspond to those of the previously described embodiments are provided with identical reference numerals, preceded by a "1" or "2," respectively.

[0055] Fig. Figure 18 shows a perspective view of the tip of a milling tool 120 with four end cutting edges 130 and a corresponding number of peripheral cutting edges 135. The flanks of the end cutting edges 130 are designated 128-1 and 128-2. In accordance with the previously described embodiments, shallow depressions 150 are formed in the flanks 128, ie, a depression structure 150 of any desired depth and width. These depressions 150, which in their details correspond to the embodiments of Fig. 1 to 17, the coolant flow that occurs in this area can be specifically influenced in such a way that the coolant is directed at least in the direction of a highly stressed area of ​​the tool cutting edges 130 or 135.

[0056] In the Fig. 18, the front cutting edges 130 are assigned different recesses 150-1, 150-2, and 150-3, each of whose contours is designed with a view to optimal long-term stabilization of the cutting edges. A different design of the recesses is recommended when cutting edges are subject to different loads due to their location, shape, or position with respect to the coolant supply. Of course, it is also possible to apply identical recesses 150 to all cutting edges.

[0057] It can be seen that the depression 150-1, which is only shown schematically, has a large area - similar to the depression according to Fig. 14 - but is limited to the flanks 128-1 and 128-2 of the end cutting edge 130. In contrast, the recess 150-2 extends into the chip groove 134. The embodiments with the recesses 150-1 and 150-2 are not claimed. The recess 150-3 relates - similar to the embodiments according to Fig. 5 to 14 - also the free surface 138 of the peripheral cutting edge 135 is included in the forced flow of the coolant.

[0058] With regard to the dimensioning - shape and depth profile - and manufacture of this recess 150-3, reference is made to the above embodiments.

[0059] The embodiment according to Fig. 19 differs from the embodiment according to Fig. 18 only in that the milling tool 220 is equipped with internal cooling channels 222. The positional relationship between the coolant-guiding recesses 250-1, 250-2, and 250-3 and the associated internal cooling channel can vary depending on the contour and other design of the recess. While the recess 250-1 encompasses the opening of the cooling channel 222, the recesses 250-2 and 250-3 end a short distance from the opening.

[0060] Of course, modifications to the illustrated embodiments are possible without departing from the basic idea of ​​the invention. Other cutting tools can also be equipped with the structure according to the invention of any depth and width.

[0061] The invention thus creates a cutting tool with a geometrically defined cutting edge, in particular a drilling or milling tool, in which the temperature of the cutting edge can be thermally stabilized over its entire length with very minimal interventions in the grinding shape, namely by introducing a flat structure into an area encompassing the flank face. If the structure is designed as a depression ending a short distance from the main cutting edge, an optimized setback of the flank face can be advantageously used to direct the cooling lubricant. At the same time, this setback limits the increase in flank face wear, whereby the enlargement of the gap between the tool and the workpiece improves the accessibility of the cutting edge to the cooling lubricant.

[0062] In a preferred embodiment, the invention relates to a drilling or milling tool, wherein the flank structure is used for coolant control. In the design as a drilling tool, it has a tip grind with a main cutting edge, a secondary cutting edge, a guide chamfer, a main and secondary flank, and a cutting edge corner. The main cutting edge lies in the area of ​​influence of a cooling lubricant (CLS) flow, which can be supplied via at least one internal coolant / lubricant channel that exits via an opening in a main flank. Within the flank of the drilling or milling tool there is at least one structure of any depth and width, which is designed in such a way that it can influence the CLS flow and direct the CLS at least in the direction of a highly stressed area of ​​a tool cutting edge (30), such as the main or end cutting edge. The tool is particularly suitable for machining difficult-to-machine materials, such asof corrosion and temperature-resistant nickel-based alloys.

Claims

[1] A rotary-driven cutting tool with a geometrically defined cutting edge, namely a drilling or milling tool, with a grinding for forming a tool cutting edge (30) which lies in the area of ​​influence of a cooling lubricant (KSS) flow, with at least one structure (50; 150-1 to 150-3; 250-1 to 250-3) of any desired depth and width located within the flank (28-1, 28-2; 128) of the cutting tool (20; 120; 22), which structure is designed in such a way that the KSS flow can be influenced by it, characterized bythat the structure is designed as a depression in the shape that the KSS can be directed at least in the direction of a highly loaded area (BS) of the tool cutting edge (30; 130, 135; 230, 235), wherein the depression (50; 50-1, 50-2; 50-1, 50-2, 50-3) is formed by a shallow groove which begins in the vicinity of the drill or milling cutter center and is led to the outer surface (38) of the secondary or peripheral cutting edge chamfer, where it opens to the secondary or peripheral cutting edge clearance surface (40). [2] Rotary-driven cutting tool according to claim 1, characterized by at least one internal cooling lubricant channel (22; 222) guided at least partially in the tool body, wherein the cooling lubricant channel (22; 222) preferably exits via a cooling channel outlet (22M; 222M) in a free surface (28-2; 228-2). [3] Rotary-driven cutting tool according to claim 1 or 2, characterized bythe design as a drilling tool with point grinding with main cutting edge (30), secondary cutting edge, guide chamfer (38), main and secondary flanks and cutting edge corner (36). [4] Rotary-driven cutting tool according to one of claims 1 to 3, characterized by that the at least one structure (50; 150; 250) is introduced into the flank surface (28-1, 28-2) in such a way that it also extends to tool surfaces adjacent to the flank surface (28-1, 28-2), such as the guide chamfer (38), secondary flank surface / back (40) or the point thinning (32). [5] Rotary-driven cutting tool according to one of claims 1 to 4, characterized bythat one or more structures (50A, 50B, 50C) are located within the free surface, preferably in the region between a cooling channel outlet (22M) of an internal cooling lubricant channel (22) guided in the tool body and the tool cutting edge, in particular the main cutting edge (30) of a drilling or milling tool, and are designed entirely or in sections over this distance. [6] Rotary-driven cutting tool according to one of claims 1 to 5, characterized by that the recess (50) follows the tool cutting edge, in particular the main cutting edge (30) of a drilling or milling tool, entirely or in sections, with a constant or variable distance (A*). [7] Rotary-driven cutting tool according to claim 6, characterized by that the distance (A*) is in the range of 50 to 300 µm, preferably in the range of 100 to 150 µm. [8] Rotary-driven cutting tool according to one of claims 1 to 7, characterized bythat several structures (50A to 50E) are used in combination or merged into one structure. [9] Rotary-driven cutting tool according to one of claims 1 to 8, characterized by that the at least one structure is introduced with a depth (T50) in the range of 20 to 350 µm. [10] Rotary-driven cutting tool according to one of claims 1 to 9, characterized by that the recess (50) extends as a recess at least in sections along the tool cutting edge, in particular the main or end cutting edge of a drilling or milling tool, and is designed in such a way that it becomes part of a coolant / lubricant channel arrangement in which coolant / lubricant (KSS) is brought into a forced flow (60-1 to 60-4) encompassing at least one selected, highly loaded area (BS) of the cutting edge. [11] Rotary-driven cutting tool according to claim 10, characterized bythat the coolant / lubricant (KSS) exits from an opening (22M; 222M) of an internal cooling lubricant channel (22; 222) guided in the tool body. [12] Rotary-driven cutting tool according to one of claims 1 to 11, characterized by that the flat groove (50) is connected to at least one branch channel groove (50-1, 50-3 to 50-5) introduced into the main free surface (28) and extending from the mouth opening (22M). [13] Rotary-driven cutting tool according to claim 12, characterized by that a branch channel groove (50-3) extending from the mouth opening (22M) runs essentially radially to the center of the drill or milling cutter. [14] Rotary-driven cutting tool according to claim 13, characterized by that several branch channel grooves (50-1, 50-3 to 50-5) are guided essentially in a star shape from the mouth opening (22M) to the flat groove (50). [15] Rotary-driven cutting tool according to one of claims 1 to 14, characterized by that the recess (50) is formed by a flat, circular segment-like removal of the flank surface (28) of the main or front cutting edge (30-1, 30-2), the removal being guided up to the outer surface (38) of the guide chamfer. [16] Rotary-driven cutting tool according to one of claims 1 to 15, characterized by that the structure (50; 150; 250) is machined by laser processing into the flank, in particular flank (28-1, 28-2; 128; 228) of the main cutting edge (30) of a drilling tool or the end cutting edge (130; 230) of a milling tool. [17] Rotary-driven cutting tool according to one of claims 1 to 16, characterized by that at least the highly stressed areas are made of a hard material, in particular solid carbide (VHM) or a cermet material.

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