Device and procedure for preparing cutting edges

Abstract

The invention relates to an apparatus (1) for preparing the edges of cutting tools (5), in particular drills, milling cutters or similar tools (5), especially carbide cutting tools, wherein the cutting tool (5) interacts during a relative metal-cutting motion with a grinding tool (2), provided with abrasive particles and flexibly fixed, and the particles of the grinding tool (2) influence the geometry of the cutting edge of the cutting tool (5), wherein the grinding tool (2) is adapted in its dimensions substantially to the dimensions of the cutting tool (5) to be prepared and is housed in an interchangeable holder (4), which is held in the region of a machine, in particular a tool grinder, and can be machined by the cutting tool (5) to prepare the edge.The invention also relates to a corresponding method and a corresponding grinding tool (2).

Description

[0001] The invention relates to a device and a method for cutting edge preparation according to the preamble of claim 1 and a method according to the preamble of claim 12 as well as a machinable grinding body according to the preamble of claim 22.

[0002] For various machining tasks, tools are needed in machining that achieve high manufacturing accuracy on the component while simultaneously providing long tool life to ensure economical and competitive product manufacturing for companies. In addition to good wear resistance, predictable wear behavior is essential to guarantee high process reliability. To improve the performance of cutting tools, particularly in the area of ​​carbide tools, cutting edge preparation has become established as an important process step in the manufacturing chain. Cutting edge preparation refers to the fine machining of the tool cutting edge after the grinding process to create the actual macro-shape of the tool.Due to the brittle nature of hard metals, microscopic defects, such as chipping along the cutting edge, can occur during the grinding process. Cutting edge preparation eliminates these defects and creates a cutting edge geometry adapted to the specific machining process. Furthermore, this load-optimized design of the cutting edge often increases its stability to such an extent that higher material removal rates can be achieved without compromising tool life. This significantly improves manufacturing efficiency.

[0003] Previously known and, in some cases, established methods for cutting edge preparation are primarily based on processes with geometrically undefined cutting edges, such as jet machining, magnetic finishing, drag finishing, and flow finishing. In addition, other separation processes, such as brushing, electrical discharge machining (EDM), laser ablation, and the grinding of radii, are known for preparing cutting edges. These methods have in common that they generally require a specialized machine or equipment, which is often associated with high investment costs. These investment costs represent a significant hurdle, especially for small and medium-sized toolmaking companies. Another disadvantage of these methods is a sometimes considerable increase in lead time in tool manufacturing. This results, in part, from the additional process time inherent in the preparation process itself.Secondly, the use of a separate machine generally requires additional handling. Furthermore, it should be noted that, according to the current state of the art, none of the methods described above are used for preparing resharpened tools. Due to the inability to prepare cutting edges in the resharpened state, these tools usually do not achieve the same service life as new tools.

[0004] Each of the aforementioned processes has specific advantages and disadvantages, relating both to the application of the process itself and to the resulting edge and surface finish of the tools. Due to their significant relevance to industry, the following discussion will focus exclusively on the processes of jet machining, brushing, drag finishing, grinding (particularly using elastically bonded grinding wheels), and the similar process of drill polishing.

[0005] In abrasive blasting, an abrasive material consisting of an abrasive and a carrier medium is accelerated at high kinetic energy through a blast nozzle onto the workpiece surface. The abrasive material is differentiated by grain type, grain size, and grain shape. The carrier medium is often a liquid or air. Besides the choice of abrasive, the most important process influences on the procedure are the blast feed rate, the blast pressure, and the blast angle. The process allows for flexible guidance of the blast nozzle or the tool being prepared, enabling the targeted machining of individual cutting edges. This makes it particularly suitable for producing complex cutting edge shapes with generally smaller radius sizes, although precise control of the material removal is very difficult.Particularly with very small tool diameters and closely spaced cutting edges, so-called passive radiation can lead to undesirable influences on other cutting edges not intended for preparation. This negatively affects process accuracy and the reproducibility of the process result. A characteristic pitting structure forms on the clearance and rake faces adjacent to the blasted cutting edge and in contact with the abrasive jet, typically resulting in an optically matte surface.

[0006] Brushing is another well-established process in industrial settings. Material removal is achieved by moving a rotating brush, impregnated with an abrasive medium, along the cutting edge of the tool. This method is suitable for efficiently producing larger and asymmetrical radii. Process-related factors include the cutting speed, feed rate, depth of cut, cutting edge angle, and brushing duration. Tool-related factors include the thread diameter, the grain size of the abrasive medium, the bristle type, and the bristle density. Due to this multitude of influencing factors, process control is complex and requires precise knowledge of the process and its interactions for accurate implementation. In addition to process control, bristle wear negatively impacts process reliability.The production of complex cutting edge shapes is also limited with smaller tool diameters.

[0007] Drag finishing, a variant of vibratory finishing, is also a widely used process in industrial settings. Material removal occurs by guiding the tools to be prepared through a loose and usually stationary abrasive medium. The tool movement is typically rotary. The rotational speed, direction of rotation, immersion depth, processing time, and the type of abrasive used are particularly important for the finishing result. Both small and large radii can be efficiently produced using this method. Furthermore, a significant improvement in surface quality can be achieved. However, its use also has some disadvantages. Because the tool is immersed in the abrasive medium, a very large contact area between the medium and the tool is created. Material removal occurs in all of these contact areas, making targeted preparation of individual cutting edges virtually impossible.Furthermore, form factors and graded radii are very difficult to set, and the rotational movement leads to significant material removal, especially with shank tools in the area of ​​larger diameters.

[0008] Cutting edge preparation can still be achieved through a grinding process. The common practice is to create a single or double chamfer along the cutting edge. A more recent approach involves creating more than two chamfers to approximate the profile of the cutting edge to a rounded shape. The use of elastically bonded grinding wheels in tool preparation is also known. One application is the fine machining of chip flutes on cutting tools.

[0009] From US patent 1,717,554 A, a polishing method for polishing contact surfaces of telephone line plugs is known, wherein the plugs are inserted into a rotating polishing body which has a central receiving opening for polishing.

[0010] From US 2009 / 253356 A1, a method for polishing and honing drills is known, wherein the drill is inserted into a container containing an abrasive medium, the drill is driven by a rotary device, displacing the abrasive medium and enabling machining of the flutes, cutting edges and drill tip, the container having openings for receiving the drill shank and tip, and the medium being pressurized to ensure uniform surface finishing.

[0011] US Patent 3,393,477 A discloses a grinding device for twist drills in which a rotating drill drives a rotary device that carries a grinding wheel and its shaft. The grinding wheel is pivotally mounted to alternately machine the cutting edges of the drill. The device also includes a coupling that positions the drill relative to the grinding device to ensure precise machining of each cutting edge. A special arrangement of gears and cams generates an optimal clearance angle at the cutting edges.

[0012] From DE 10 2011 054 276 B4, a method for preparing the cutting edges of cutting tools, in particular drills or milling cutters, especially carbide cutting tools, is known. In this method, after the desired cutting geometry has been produced, the cutting tool is first adjusted or aligned to the necessary workpiece data according to the cutting geometry and / or cutting characteristics, set into a rotary motion, and then inserted or drilled into a grinding wheel with silicon carbide, tungsten carbide, or diamond components, which is flexibly bonded with a rubber-containing binder, at a depth and position on the circumference of the grinding wheel selected according to the cutting edge geometry, while maintaining the rotary motion. In this process, a rotating tool is moved into a grinding wheel with a defined drilling path and angle of approach.However, this kinematics are only feasible on a very limited number of machines and therefore cannot be considered a universal preparation method. Furthermore, this method does not allow for the setting of cutting edge radii extending across the tool diameter. Additionally, drilling in solid material always results in significant rounding of the cutting edge corner and the chisel edge, for example, on twist drills, and the grinding wheel requires complex dressing after extensive use. Another disadvantage of this method is the inability to prepare long, overhanging tools due to the lack of a guide. This method requires complex programming to determine the position of the bore and the angle of approach between the workpiece (in this case, the ground cutting tool) and the tool (the grinding wheel to be machined).Furthermore, after complete circumferential machining, the grinding wheel must be returned to its initial state using external processes. Additionally, mounting the grinding wheel on a grinding mandrel may occupy additional grinding wheel magazine slots.

[0013] Cutting edge preparation has proven to be an effective means of increasing the performance and machining quality of cutting tools, but it usually requires additional machinery and equipment. This results in high investment costs for this equipment, as well as additional workpiece handling costs, which in a high-wage country like Germany can represent a significant portion of the preparation costs. These technological and economic aspects highlight the need for the development of an advanced cutting edge preparation process, particularly suitable for use by small and medium-sized cutting tool manufacturers, and one that specifically meets the requirements for low investment and operating costs, ease of implementation, and short tool preparation cycle times.

[0014] The object of the present invention is to provide a simple and cost-effective method for the targeted preparation of cutting edges on rotationally symmetrical cutting tools, in particular with a clamping shank (shank tools), with regard to their microscopic shape, without incurring additional investment costs for machines for the tool-manufacturing company.

[0015] The solution to the problem according to the invention is achieved with respect to the device by the characterizing features of claim 1, with respect to the method by the characterizing features of claim 12, and with respect to the grinding body by the characterizing features of claim 22, each in conjunction with the features of the associated preamble. Further advantageous embodiments of the invention are set forth in the dependent claims.

[0016] The invention relates to a device for preparing the cutting edges of cutting tools, in particular drills or milling cutters, especially carbide cutting tools, with a substantially cylindrical grinding body and a sleeve-like holder, wherein the cutting tool interacts with the grinding body, which is provided with abrasive particles and flexibly bonded, during a relative movement, and the particles of the grinding body influence the edge geometry of the cutting tool. Such a generic device is further developed according to the invention in that the dimensions of the grinding body are substantially adapted to the dimensions of the cutting tool to be prepared, wherein the cylindrical circumferential dimensions of the grinding body are substantially adapted to the circumferential dimensions of the cutting tool to be prepared.and wherein the grinding element is received in a bore of the replaceable holder, which is arranged in the area of ​​a machining device, in particular a tool grinding machine, and wherein the grinding element is held in the holder such that the grinding element can be machined by the cutting tool for cutting edge preparation, wherein the grinding element has a larger outer diameter than the outer diameter of the cutting tool so that the cutting edges of the cutting tool come into contact only with the grinding element and not with the replaceable holder during cutting edge preparation. In contrast to known solutions for cutting edge preparation, the dimensions of the grinding element are adapted to the dimensions, e.g., the circumferential dimensions, of the cutting tool to be prepared.This results in significant material savings for the grinding wheel and allows for targeted influence and improvement of the cutting edge preparation process. Only the amount of abrasive material required for the grinding wheel is needed, thus making the process more economical. Furthermore, the otherwise necessary dressing of large grinding wheels between each cutting edge preparation step is eliminated. The dimensionally adapted grinding wheel is also pressed into a corresponding, replaceable, sleeve-like holder, which is positioned, for example, in the working area of ​​a tool grinding machine and can be machined by the cutting tool used for edge preparation.The interchangeable sleeve-like holder allows for pre-fitting the holder with new or different grinding wheels independently of the actual machining process, e.g., in the grinding machine. This significantly decouples the grinding wheel changeover from the actual machining operation. Furthermore, the dimensionally adapted grinding wheel can be stored in a particularly space-saving manner, thus minimizing disruption to a preceding grinding process, such as on the tool grinding machine, and can be kept readily available for cutting edge preparation. This makes it considerably easier and more straightforward to perform the cutting edge preparation on the same tool grinding machine after the actual grinding of the cutting tool, ideally in the same setup.Since no or only minimal additional equipment is required on the tool grinding machine, and this equipment also takes up little or no additional space in the grinding machine's work area, even smaller tool grinding shops can offer cutting edge preparation alongside the actual tool grinding without having to invest in expensive additional equipment on the grinding machine or purchase additional machines. Of course, it is also possible to use and integrate the device on other machining equipment besides a tool grinding machine, such as drilling machines, lathes, or similar universal or special-purpose machines on which cutting tools to be prepared are machined or used, and on which the cutting edge preparation can then be carried out close to the process or as needed.to ensure defined cutting conditions. The device for cutting edge preparation can also be used on any machine, and in particular any machining equipment, that allows relative movement between the cutting tool and the grinding wheel and on which cutting edge preparation can be performed. In this sense, the term "machining equipment" is to be understood as general and not restrictive. When, for example, the application of the device on a tool grinding machine is mentioned here, this always includes other machining equipment or general equipment as well.

[0017] It is particularly advantageous if the replaceable holder is positioned within the working area of ​​a tool grinding machine, preferably within a grinding wheel holder of the tool grinding machine. The installation space of the grinding wheel holder is a normally unused area on the grinding wheel holder, usually located in the extension of the clamping cone or similar clamping device in the area surrounded by the disc-shaped grinding wheel. This collar, onto which the grinding wheel is mounted, is typically made of solid material and otherwise unused. Therefore, this space, centrally located within the working area of ​​the tool grinding machine, can now be used to create an installation space for the replaceable holder with the grinding wheel, in which the grinding wheel is held by the cutting tool for machining of the cutting edge.With this arrangement of the compact grinding wheel, adapted to the dimensions of the cutting tool, no additional space is required for edge preparation. Furthermore, edge preparation can be carried out in an easily accessible area of ​​the tool grinding machine's workspace that does not require any modifications to the kinematics for moving the grinding wheel or cutting tool. Of course, it is also conceivable to position the compact grinding wheel, adapted to the dimensions of the cutting tool, at a different location within the tool grinding machine's workspace. Such a position could be, for example, in the workspace of a tool grinding machine, particularly in the area of ​​the grinding spindle, or at another location.Another possible design option is a space-saving pallet system in which the previously described interchangeable holders containing the grinding wheels are stored in a magazine with the same or different diameters. This allows for interaction between the tool being manufactured and the grinding wheel for a wide variety of ground tools. The pallet-style device can be round, square, or rectangular and, depending on its dimensions, can hold a specific number of interchangeable holders with grinding wheels. It is also conceivable to integrate the interchangeable holder into moving parts such as the spindles of other machining equipment, for example, the work spindle of a lathe or similar machine.

[0018] According to the invention, the grinding body according to claim 22 is essentially cylindrical. Since the cutting tools to be prepared also typically have at least fundamentally cylindrical dimensions, a similarly cylindrical design of the grinding body allows for a high degree of adaptation to the dimensions and shape of the cutting tools, thereby enabling a significant saving of abrasive material for the grinding body.In the embodiment according to the invention, the cylindrical circumferential dimensions of the grinding body are essentially adapted to the circumferential dimensions of the cutting tool to be prepared, so that the grinding body can be successively and largely completely machined during the course of the usually several cutting edge preparations of the cutting tools to be processed one after the other, and thus no unused residue of the abrasive material has to be disposed of.

[0019] Furthermore, it is a significant advantage that the grinding wheel can simply be replaced with a new one after it has reached the end of its service life. This only minimally increases the machining time for a cutting tool, and the cutting edge preparation process, which would otherwise require changeovers or similar adjustments, does not unnecessarily prolong the manufacturing time of the cutting tool.

[0020] In a first embodiment, the grinding wheel is arranged in a way that allows for easy replacement within the replaceable holder, preferably by pressing it into the holder. For this purpose, for example, the rotationally symmetrical grinding wheel can be manufactured with a very small allowance adapted to the diameter of the cutting tool to be prepared and pressed into the replaceable holder. Pressing it in creates a simple and sufficiently rotationally rigid connection between the grinding wheel and the replaceable holder to reliably absorb the machining forces during cutting edge preparation.

[0021] In a particularly advantageous embodiment, it is conceivable to design the replaceable holder to be inserted into a preferably central bore in the grinding wheel holder, preferably in the mounting collar for the grinding wheel. This easily accessible and, as already described, largely unused volume can be provided on almost any tool grinding machine by a simple modification of a conventional grinding wheel holder on a machine-side clamping element for the grinding wheel, and does not change the working area of ​​the tool grinding machine, or only to a negligible extent. Here, too, according to the invention, a corresponding installation space for inserting the replaceable holder can be provided on other machine tools, for example, in a spindle of a lathe or similar machining equipment.

[0022] In a further embodiment, the replaceable holder can have an external thread that can be screwed into the internally threaded bore in the grinding wheel holder. This allows the replaceable holder to be installed and secured precisely and quickly in the bore of the grinding wheel holder. Alternatively, the replaceable holder can be pressed or inserted into a preferably central bore in the grinding wheel holder and secured there against rotation, for example by a bayonet fitting, a clamp, or the like.

[0023] Especially for edge preparation of long, protruding cutting tools with a large length-to-diameter ratio, a guide bushing can be arranged in the area of ​​the replaceable grinding wheel holder. This allows such long, protruding cutting tools to be prepared by guiding them through the bushing, resulting in more precise and reliable machining than without additional guidance. Examples of such long, protruding cutting tools include asymmetrical deep-hole drills, single-flute drills, twist drills, or similar tools with a large length-to-diameter ratio, which otherwise tend to deflect easily during machining or, due to their length, are prone to vibration during edge preparation.In a further embodiment, the guide bushing can be arranged relative to the replaceable holder, preferably in extension of the replaceable holder, in such a way that the guide bushing guides and supports the long, projecting cutting tool in front of the area of ​​machining of the grinding body.

[0024] Furthermore, it is conceivable that electrical conductors and / or sensor elements could be integrated into the interchangeable holder, providing information about the cutting edge preparation process. For example, non-contact sensors or similar devices could be used to additionally monitor and, if necessary, influence the processing sequence during cutting edge preparation. In a further embodiment, it is conceivable that the sensor elements could be equipped with batteries integrated into the interchangeable holder for power supply. These batteries could be charged in the grinding wheel magazine or externally when not in use. This would allow sufficient energy to be stored in the batteries during idle periods when the interchangeable holder is not in use, enabling the aforementioned monitoring processes during cutting edge preparation to be carried out once the respective interchangeable holder has been installed.

[0025] It is particularly advantageous if the grinding wheel contains abrasive particles, especially silicon carbide, aluminum dioxide, or diamond, and is successively and completely removed by the cutting tools being prepared. By selecting or mixing the abrasive particles used in the grinding wheel, and in further developments also by mixing finer and / or coarser abrasive particles, the grinding wheel's cutting behavior, and thus the achievable cutting edge preparation, can be influenced within wide limits. It is also conceivable to create an inhomogeneous distribution of finer and / or coarser abrasive particles within the grinding wheel, for example, to achieve different preparation behaviors.to produce different preparation results in individual areas of the cutting tool, adapted to the respective geometry of the grinding wheel being prepared.

[0026] According to the invention, the grinding body has an axially extending perforation that is matched to the cutting tool diameter, within which the cutting tool is not affected by the particles of the grinding body. For example, when preparing the cutting edges of drill bits, it is advantageous to prepare the chisel edge area of ​​the drill bit differently or not at all than the main cutting edge area. Because no material from the grinding body is present in the chisel edge area due to the perforation, the chisel edge area remains unchanged.

[0027] Furthermore, it is conceivable that the grinding body has sections with different bond hardnesses, particularly radial annular sections of varying hardness. The bond of the grinding body's abrasive particles directly affects the grinding body's machining behavior and thus the local cutting edge preparation of the cutting tool. Different bond hardnesses or different areas of hardness allow for further adaptation of the cutting edge preparation to the requirements of the specific cutting tool. For example, the core of the grinding body can have a higher bond hardness than the outer area to achieve uniform cutting edge rounding due to the elastic deformation of the rotationally symmetrical grinding body.

[0028] The invention further relates to a method for preparing the cutting edges of cutting tools, in particular drills or milling cutters, especially carbide cutting tools, wherein the cutting tool interacts with a grinding body provided with abrasive particles and flexibly bonded, which is essentially cylindrical, during a relative movement, and the particles of the grinding body influence the edge geometry of the cutting tool, according to which the grinding body is adapted with respect to its dimensions essentially to the dimensions of the cutting tool to be prepared, wherein cylindrical circumferential dimensions of the grinding body are essentially adapted to circumferential dimensions of the cutting tool to be prepared, and wherein the grinding body is mounted in a bore by an interchangeable, in the area of ​​a machining device, in particular a tool grinding machine, e.g.in the working area of ​​a tool grinding machine or other machining device, the grinding body is pressed into a sleeve-like holder in a rotationally fixed manner, in which the grinding body is successively completely machined by the cutting tools to be prepared, wherein the grinding body has a larger outer diameter than the outer diameter of the cutting tool so that the cutting edges of the cutting tool only come into contact with the grinding body and not with the replaceable sleeve-like holder during the cutting edge preparation, and wherein the grinding body has an axially extending perforation adapted to the diameter of the cutting tool, within which the cutting tool is not affected by the particles of the grinding body.The essential properties and advantages of the method are directly related to the device described and explained above; therefore, its described properties and advantages can also be used to characterize the method according to the invention.

[0029] A particular advantage here is that the cutting edge preparation can be carried out in the same setup immediately after the initial production of the cutting tool's shape or after regrinding the cutting tool on the same machining equipment, such as a tool grinding machine or other machining device. This eliminates the need for additional equipment for separate cutting edge preparation, and also allows the cutting edge preparation to be performed directly in the same setup and on the same tool grinding machine or machining device used for the basic shaping of the cutting tool. Furthermore, the cutting edge preparation can also be performed after regrinding a previously used cutting tool, thus allowing the advantages of cutting edge preparation to be utilized even with such reground cutting tools.

[0030] A particular advantage is that the relative movement between the grinding wheel and the cutting tool, especially through the superposition of rotational directions and speeds, allows for a wide range of cutting speed adjustments during machining of the grinding wheel. The cutting speed during edge preparation influences many parameters of the edge preparation process and, therefore, with a large range of cutting speed options, can be used to precisely control the results of the edge preparation.

[0031] It is also conceivable that the grinding wheel and / or the cutting tool perform rotational movements during the machining of the grinding wheel. Thus, in addition to the usual rotation of the cutting tool, the grinding wheel can also rotate, possibly in the opposite direction or at different rotational speeds. This allows, in particular through the superposition of the rotational movements of the grinding wheel and / or cutting tool, targeted rounding and / or tilting of the cutting edge of the cutting tool to be produced, or it can also enable the production of asymmetrical cutting edge profiles and / or cutting edge profiles that vary across the tool diameter.

[0032] Furthermore, it is conceivable that the cutting tool to be prepared alone performs the necessary translational and rotational movements during the cutting edge preparation.

[0033] It is also conceivable that the grinding wheel, with sections exhibiting different bond hardness levels, could generate variable radii across the cutting edge of the cutting tools. For this purpose, the grinding wheel can be manufactured specifically and tailored to the cutting tool being prepared, with locally or sectionally variable bond hardness levels that influence the local machining by the cutting tool and thus the local cutting edge preparation.

[0034] Furthermore, it is conceivable that the grinding body, through an axially extending perforation adapted to the cutting tool diameter, in which the cutting tool is not influenced by the particles of the grinding body, only subjects certain areas of a cutting tool, in particular e.g. the main cutting edges of a drill tool, to cutting edge preparation and leaves other areas, in particular the transverse cutting edge of a drill tool, unrounded.

[0035] The grinding body can also have external dimensions adapted to the cutting tool diameter, so that only specific areas of the cutting edges of the cutting tool are subjected to cutting edge preparation.

[0036] For certain cutting tools requiring preparation, it is conceivable that the cutting tool, with its main and secondary cutting edges, particularly milling tools, reaming tools, and / or step drills, uses abrasive media with different properties for the preparation of the cutting edges. For example, the main cutting edges of a reamer can be prepared with a differently shaped or dimensioned abrasive media than the secondary cutting edges in order to achieve the optimal preparation result for each.

[0037] The invention further relates to a grinding body for carrying out the method according to claim 12, wherein the cylindrical circumferential dimensions of the grinding body are substantially adapted to the circumferential dimensions of the cutting tool to be prepared.

[0038] A particularly preferred embodiment of the device according to the invention is shown in the drawing.

[0039] They show: Figure 1 - in a simplified representation showing the basic structure and function of a device according to the invention, arranged in the grinding wheel holder of a grinding wheel before the cutting edge preparation of a drill bit; Figure 2 - a device according to the invention. Figure 1 with an additional guide bushing in front of the cutting edge preparation of a long projecting single-lip drill, Figures 3a-3c - views and sections through differently constructed grinding bodies of the device according to the invention. Figure 1Figures 4a-4d show cutaway detailed views of the replaceable holder and grinding elements arranged therein for the cutting edge preparation of various cutting tools. Figure 5 shows a pallet-like magazine on a device according to the invention with places for receiving a number of replaceable holders and grinding elements arranged therein.

[0040] In the Figure 1The basic structure and function of a device 1 according to the invention can be seen in a simplified representation, arranged, for example, in the grinding wheel holder 3 of a grinding wheel 14 upstream of the cutting edge preparation of a cutting tool 5, here in the form of a drill bit. The device 1 is arranged on a commercially available tool holder, here designed as a conical holder 10 of a grinding wheel 14, as is common for commercially available tool grinding machines. The specific design of the grinding machine-side holder of the device 1 is secondary and can include all types of mechanical interfaces to the tool grinding machine. Such arrangements can also be implemented on other machining equipment such as drilling machines, lathes, or similar devices.The design of the tool grinding machine shown in the figures is only an example and can be modified in many ways.

[0041] A mounting flange 3 for receiving the grinding wheel 14 is arranged on the conical mount 10 in the working area of ​​the tool grinding machine. The grinding wheel 14, with its holes, is placed onto this flange and secured in the conventional manner by means of a threaded nut 9. This mounting flange 3 is usually made of solid material and has no other function besides supporting the grinding wheel 14.

[0042] According to the invention, a portion of this otherwise solid mounting flange 3, which is centrally located in the working area of ​​the tool grinding machine, is used to accommodate the device 1 according to the invention. For this purpose, a central longitudinal bore 11 is machined into the mounting flange 3 from the working area of ​​the tool grinding machine as a blind bore, into which a sleeve-like and easily replaceable holder 4 for a grinding wheel 2, which will be explained in more detail later, can be inserted. Due to this arrangement of the device 1, the device 1 does not impede the normal operation of the tool grinding machine and nevertheless provides a receptacle for a grinding wheel 2, which can be used for preparing the cutting edge of a cutting tool 5.

[0043] The replaceable holder 4 has an outer diameter such that it can be inserted into the longitudinal bore 11 of the mounting collar 3 with virtually no play. The replaceable holder 4 can be secured in the longitudinal bore 11 by means of an end thread 6 on its outer surface, which can be screwed into a corresponding mating thread in the longitudinal bore 11. Alternatively, the replaceable holder 4 could be secured in the longitudinal bore 11 by pressing it in or by another form-fit or force-fit method, provided that a rotationally fixed connection is ensured while allowing for easy replacement of the replaceable holder 4.

[0044] Inside the sleeve-like, replaceable holder 4 is also a bore 23 into which a cylindrical grinding element 2 can be inserted or pressed in a rotationally fixed manner. This grinding element 2 can be used to interact with the cutting edges 7 of the cutting tool 5 during the preparation of the cutting edge of the cutting tool 5. The grinding element 2 consists of a flexibly bonded abrasive particle matrix, for example, rubber-bonded abrasive particles made of hard materials.

[0045] The grinding body 2 is matched to the circumferential dimensions of the cutting tool 5, here the outer diameter of the drill, with regard to its cylindrical outer dimensions and has a slightly larger outer diameter than the outer diameter of the cutting tool 5, so that the cutting edges of the cutting tool 5 only come into contact with the grinding body and not with the replaceable holder 4 during the cutting edge preparation.

[0046] To prepare the cutting edges of the cutting tool 5, the cutting tool 5, in the form of a drill bit, is positioned in the longitudinal bore 11 of the mounting collar 3 in front of the device 1, for example, after the basic grinding of the tool shape using the grinding wheel 14, such that the axis of the cutting tool 5 and the longitudinal bore 11, and thus the interchangeable holder 4, are aligned. During relative rotation between the cutting tool 5 and the grinding body 2, the cutting tool 5 is then moved towards the grinding body 2 in the feed direction until the cutting edges of the cutting tool 5 interact with the grinding body 2 as intended, machining and preparing it in the process. The grinding body 2 is thus machined away at least a portion of its length and consequently shortened in the longitudinal direction.After the cutting edge preparation of the cutting tool 5, the cutting tool 5 is moved out of the replaceable holder 4 against the feed direction 24 and can be removed.

[0047] The process can then be repeated with the next cutting tool 5, whereby the grinding wheel 2 is progressively worn down and must be replaced when a wear limit is reached. For this purpose, the entire replaceable holder 4, along with the remaining grinding wheel 2, is removed from the longitudinal bore 11 and replaced with a replaceable holder 4 pre-equipped with a fresh grinding wheel 2. The quick exchange of the replaceable holder 4 with the grinding wheel 2 allows work to continue immediately. Additional identical replaceable holders 4 can be stored, for example, in other grinding wheel mounts as a depot, for use when the preparation remains the same. This allows the replacement of the grinding wheel 2 to be postponed until the job is completed or the wear limits of the grinding wheels 14 are reached.

[0048] In the Figure 2 is a modified device 1 according to Figure 1The illustration shows a modified cutting edge preparation tool 13, in this case a single-lip drill, for the preparation of the cutting edge of a long, projecting cutting tool 13. Since such long, projecting cutting tools 13 tend to deflect laterally and begin to vibrate during grinding and cutting edge preparation, the cutting tool 13 is guided and supported by a guide bushing 12 located at the front of the replaceable holder 4, thus minimizing or eliminating the negative effects of the long projection.

[0049] In the Figures 3a to 3c are views and sections through differently constructed grinding bodies 2 of the device 1 according to the invention. Figure 1 The figures shown represent exemplary modifications of the grinding body 2.

[0050] In the Figure 3aA grinding body 2, homogeneously formed over the entire machining area of ​​the grinding body 2, can be identified, as is also the case in the Figure 1 is shown.

[0051] The Figure 3b Figure 1 shows a grinding body 2 with a central perforation 15, which can be used, for example, as a cutting tool 5 for preparing the cutting edges of a drill bit. In the area of ​​the perforation 15, the drill bit does not interact with the grinding body 2, as there is no abrasive material present there. As a result, the cutting tool 5, designed as a drill bit, is not affected in the area of ​​the sensitive chisel edge and retains the shape obtained from the previous grinding operation with the grinding wheel 14. Only in the area of ​​the main cutting edges are the main cutting edges prepared by the sleeve-shaped form of the grinding body 2.

[0052] It is also like in Figure 3cAs shown, it is conceivable to manufacture the outer region 17 and the core region 16 of the grinding body 2 from different abrasive particles or from the same abrasive particles with different bond hardness and thus different machining properties. For example, the core region 16 of the grinding body 2 can have a higher bond hardness than the outer region 17 in order to minimize elastic deformation at the inner cutting edge of the cutting tool 5. Many modifications of the grinding body 2 are conceivable here, depending on the cutting tool 5 to be prepared and its shape.

[0053] In the Figures 4a to 4dThe figures show cutaway detail views of the replaceable holder 4 and the grinding elements 21, 22 arranged therein for the cutting edge preparation of various cutting tools 18, 19 and 20. All tools 18, 19 and 20 have in common that they have different main and secondary cutting edges to be prepared, which cannot be prepared easily or at all in a single pass.

[0054] For example, the reamer 18 can be used in the Figure 4a The main cutting edges are prepared with section 22 of the grinding body 2, and the secondary cutting edges are prepared simultaneously with section 21 of the grinding body 2. However, it is also conceivable to prepare the secondary cutting edges according to... Figure 4b In one of the individual processing operations following the preparation of the main cutting edges, only the sub-area 21 of the grinding body 2 is to be prepared on the secondary cutting edges.

[0055] In the Figure 4cThe cutting edge preparation of a step drill 19 can be seen, the two steps of which are prepared simultaneously on two, for example, differently bonded partial areas 21 and 22 of the grinding body 2.

[0056] The Figure 4d shows a cutting edge preparation of a milling cutter 20 only on the secondary cutting edges that interact with a partial area 21 of the grinding body 2.

[0057] The Figure 5Figure 1 shows a possible embodiment of a pallet-like magazine 25 on a device 1 according to the invention, with receptacles 26 for receiving a number of interchangeable holders 4 and grinding wheels 2 arranged therein. The interchangeable holders 4 with the grinding wheels 2 can be stored in such a pallet-like magazine 25 in the same or different diameters. This allows for simple and automated exchange of the interchangeable holders 4 with the required grinding wheels 2, enabling a fast and automated interaction between the cutting tool 5 to be produced and the appropriate grinding wheel 2 for a large number of ground tools 5.The device, designed here as a pallet-like magazine 25, can be round, square or rectangular and, depending on its dimensions, provide a certain number of receptacles 26 for interchangeable holders 4 with the grinding bodies 2.

[0058] The following section briefly explains the essential features and advantages of the invention: The basic idea of ​​the method according to the invention is the use of a flexibly bonded grinding body 2 made of abrasive particles, which is shown here, by way of example, installed in a specially developed grinding wheel holder 3. During the defined machining of such a grinding body 2, material is removed from the cutting edge of the cutting tool 5, which can be used for targeted preparation. This method is carried out, for example, on a conventional tool grinding machine and can therefore be integrated at the end of the process chain for tool manufacturing or tool regrinding without any further handling effort. The material removal required for preparation is generated by the relative movement between the grinding body 2 and the cutting tool 5. The cylindrical grinding body 2 is, for example,clamped in place in the grinding wheel holder 3, while the required translational and rotational movements are performed by the cutting tool 5 to be prepared.

[0059] Furthermore, in this case, by selectively superimposing the rotation directions of the cutting tool 5 and the grinding wheel holder 3, it is possible to set specific radii and tilts of the cutting edge. Additionally, by constructing the grinding body 2 with different degrees of hardness, variable radii can be generated across the cutting area of ​​the cutting tool 5. The rounding of the chisel edge of the cutting tool 5 due to established preparation methods also presents a known problem. By using a grinding body 2 with a hole pattern 15 matched to the tool diameter 5, it becomes possible to adapt the main cutting edges, e.g., of a drill 5, to the preparation process while avoiding rounding of the chisel edge. The same applies to precisely matching the diameter of the grinding body 2 to the diameter of the cutting tool 5 to be prepared.

[0060] Furthermore, due to the free process kinematics, there are other areas of application, such as the preparation of reamers, micro milling tools and step drilling tools.

[0061] The machining of the grinding body 2 results in material removal from the cutting edge of the cutting tool 5, thereby rounding it. The advantage of the method according to the invention is that tool production (grinding the macro shape) and the defined generation of the microscopic cutting edge shape can be carried out, for example, on the same tool grinding machine or machining equipment. The machining of the grinding body 2 ensures a continuous supply of fresh abrasive medium, thus maintaining constant preparation conditions throughout the process. The tool's influence is limited to the areas of the cutting tool 5 that come into contact with the grinding body 2, which is an advantage over other preparation methods, such as drag finishing or jet machining.In addition to the low investment costs, the preparation costs per tool are low, as the replacement of the grinding elements 2 can be done quickly and easily.

[0062] In particular, the rounding of the cutting edges of long, overhanging cutting tools 13 with a high length-to-diameter ratio (I / d ratio) requires, according to the current state of the art, special handling and complex process control if a suitable cutting edge preparation is to be achieved. The device according to the invention offers the potential that even such long, overhanging cutting tools 13 can be prepared on the tool grinding machine or machining equipment in a very short time due to the simple kinematics, machining in a single setup, and within existing production processes. In addition to cutting tools 13 with a high I / d ratio, conventional rotationally symmetrical cutting tools can also be prepared using this method by means of a minor modification of the grinding media 2.

[0063] In addition to rounding the cutting edges of new tools 5, the inventive method can also be used to prepare cutting tools 5 that have been reground and are therefore already coated with a hard material layer on certain functional surfaces. According to current knowledge, this is not possible with currently available methods, which is why the performance of reground cutting tools 5 is usually significantly lower than that of new cutting tools 5.

[0064] The decisive factor for the implementation of the device 1 according to the invention is the mounting of the replaceable holder 4, for example, in the grinding wheel holder 3. The grinding wheel holders 3 commonly used on tool grinding machines have corresponding interfaces to the tool grinding machine spindle. These are usually designed as hollow taper shanks (HSK), taper shanks (SK), or other, mostly standardized, interfaces to allow for high flexibility and accuracy when changing grinding wheels. For tool grinding, the grinding wheels are usually placed on a mandrel 3, e.g., with a diameter d = 20 mm, positioned by spacer rings, and fixed by a clamping nut 9. The core of the mandrel 3 has previously had no function.By installing the replaceable holder 4, here in a bore 11 with an internal thread, the mandrel 3 is given an additional function, and the grinding wheel holder 3 is significantly enhanced in terms of its range of applications. Besides securing the replaceable holder 4, the screwable or otherwise attachable connection also allows for the implementation of other functional elements not related to cutting edge preparation. Corresponding holders can also be provided on other machining equipment, such as lathes, drilling machines, or other specialized or universally applicable equipment.

[0065] The grinding media 2, specifically developed for cutting edge preparation applications, feature an elastic bond between the abrasive particles, with a hardness determined according to the specific application. These grinding media are rotationally symmetrical and impregnated with fine or coarser abrasive particles, such as silicon carbide, aluminum dioxide, or diamond. The cutting tools 5 to be prepared successively and completely machine the grinding media 2. The rotationally symmetrical grinding media 2 are adapted to the diameter of the cutting tool 5 being prepared, manufactured with very little excess material, and pressed into the replaceable holding element 4. This prevents or significantly minimizes the rounding of the exposed cutting edges of the cutting tools 5 compared to existing methods.In addition to rotationally symmetrical base bodies made of a defined bond hardness, grinding bodies 2 can also be produced that have different degrees of hardness and are accordingly adapted to the application and the diameters to be machined. Of particular note here is the possibility that, in the case of cutting tools 5, it may be necessary for the core 16 of the grinding body 2 to have a higher hardness than the outer area 17 in order to achieve a uniform cutting edge rounding due to the elastic deformation of the rotationally symmetrical grinding body 2.

[0066] In addition, the process kinematics offer possibilities, for example, by superimposing the directions and speeds of rotation, to cover a wide parameter range with regard to cutting speeds when machining the grinding wheel 2, independent of the performance of the workpiece and tool spindles. Furthermore, differently oriented, counter-rotating and co-rotating movements of the grinding wheel holder 3 with integrated grinding wheel 2 and the cutting tool 5 to be prepared allow for and adjustment of the cutting edge tilt and the form factor κ. By introducing perforations 15, inserting cores 16 with different hardnesses, abrasive particles and grain sizes, and the flexible shaping of the grinding wheel 2, this method offers the possibility of being transferred to many other variants of cutting tools 5.In addition, a different kinematics can be developed and implemented by superimposing the axes of the grinding wheel holder 3, which is similar to milling and thus also enables the targeted preparation of various milling tools 5 on the face and / or peripheral cutting edges.

[0067] In addition to the previously described use for grinding wheels 2 for cutting edge preparation, the device 1 can also be expanded by incorporating measuring technology or sensors. By integrating electrical conductors and sensors into the interchangeable holder 4, it would even be possible to implement electronic monitoring electronics equipped with accumulators and charge them via suitable charging technology either in the grinding wheel magazine or externally when not in use.

[0068] Due to the integration of device 1, e.g., into the grinding wheel holder 3, the acquisition costs are only marginally higher compared to conventional grinding wheel holders 3. This integration into the grinding wheel holder 3 also means that the concept can be used on virtually any tool grinding machine or machining center. This eliminates the investment in additional equipment required for most previously known methods, including the associated maintenance and repair costs, as well as workpiece handling after the grinding process. While the complete machining on the tool grinding machine does result in downtime during which the machine cannot be used for its primary purpose, this is negligible due to the very short process times of < 5 s per preparation. Tool changes can be performed quickly and easily with a clever arrangement of the grinding wheel packs on the grinding mandrel or...by equipping each grinding wheel holder 3 with the device 1 according to the invention, thereby increasing overall productivity and significantly reducing manufacturing costs.

[0069] The adaptation of the grinding wheel 2 to the diameter of the cutting tools 5 and the previously defined maximum interference of the grinding wheel 2 to be machined guarantee a virtually negligible influence on the cutting edges and secondary cutting edges of the cutting tools 5. Additionally, due to the contact area between the cutting tool 5 and the grinding wheel 2 being machined, which is limited by the chip thickness, there is no influence whatsoever on the peripheral surfaces of the cutting tool 5. Due to the defined length of the rotationally symmetrical grinding wheel 2 within the replaceable holder 4, a number of cutting tools 5, dependent on the diameter and target radius, can be machined using the presented concept until the grinding wheel 2 to be machined is completely used up. By replacing the replaceable holder 4, or...The change to a different grinding wheel holder 3 with the same grinding wheel 2 enables seamless, process-chain-integrated machining. The free kinematics provided by the mounting in the grinding wheel holder 3 also offer the potential to implement a different process kinematics on the tool grinding machine, similar to milling. This opens up possibilities for preparing the main and secondary cutting edges of the cutting tools 5 with different cutting edge radii and form factors.

[0070] In addition to varying the shape of the grinding media 2 and the bond hardness, it is possible to generate different cutting edge rounding profiles by adjusting the kinematic engagement conditions. Of particular importance here are the rotation direction of the cutting tool 5, the rotation direction of the grinding media 2, the dwell time at the bore bottom, and the feed rate per revolution.

[0071] For long, overhanging deep-hole drilling tools 13 with varying diameters, a guide for the tool tip is necessary to enable cutting edge preparation without damaging the cutting tool 13. This requires an adjustment of the interchangeable holder 4. The guide for the cutting tool 13 must be dimensioned so that the grinding element 2 aligns with the workpiece axis and the elastic deflection of the cutting tool 13 is compensated. The complexity of the preparation results from the requirements for the cutting edge. In addition to a greater rounding of the outer cutting edge, a significantly reduced rounding of the inner cutting edge must also be achieved when using single-lip deep-hole drilling tools. Item number list

[0072] 1- Device according to the invention 2- Grinding body 3- Mounting collar grinding wheel holder 4- Interchangeable holder 5- Cutting tool 6- Threaded interchangeable holder 7- Cutting edge cutting tool 8- Clamping thread for grinding wheel 9- Clamping nut for grinding wheel 10- Tool cone 11- Bore in grinding wheel holder 12- Guide bushing 13- Single-lip drill 14- Grinding wheel 15- Perforation 16- Core with higher bond hardness 17- Circumferential area with lower bond hardness 18- Reaming tool 19- Step drill 20- Milling tool 21- Surrounding grinding body 22- Internal grinding body 23- Bore holder 24- Feed direction 25- Pallet-like magazine 26- Holders

Claims

1. Apparatus (1) for a cutting-edge preparation of cutting tools (5), in particular of drills or milling tools, in particular of hard-metal cutting tools, with a grinding body (2) that is realized substantially cylindrically, and with a sleeve-like holder (4), wherein during a relative movement the cutting tool (5) interacts in a machining fashion with the flexibly-bonded grinding body (2) that is provided with abrasive particles, the particles of the grinding body (2) influencing the edge geometry of the cutting tool (5), characterized in that the grinding body (2) is adapted with its dimensions substantially to the dimensions of the cutting tool (5) that is respectively to be prepared, wherein cylindrical circumferential measurements of the grinding body (2) are substantially adapted to circumferential measurements of the cutting tool (5) that is to be prepared, wherein the grinding body (2) is pressed, in a rotationally fix fashion, into a bore (23) of the exchangeable sleeve-like holder (4), which is suitable to be held in the region of a processing device, in particular of a tool grinding machine, and wherein the grinding body (2) is held in the sleeve-like holder (4) in such a way that the grinding body (2) is machinable by the cutting tool (5) for the cutting edge preparation, wherein the grinding body (2) has an outer diameter that is greater than the outer diameter of the cutting tool (5), such that in the cutting edge preparation the cutters of the cutting tool (5) come into contact only with the grinding body (2) and not with the exchangeable holder (4), and wherein the grinding body (2) has an axially-extending perforation (15), which is adapted to the cutting tool diameter (5) and within which the cutting tool (5) is not affected by the particles of the grinding body (2).

2. Apparatus (1) according to claim 1, characterized in that the exchangeable holder (4) is held so as to be insertable in a grinding disk receptacle (3) of a tool grinding machine.

3. Apparatus (1) according to any one of the preceding claims, characterized in that the rotationally symmetrical grinding body (2) can be manufactured and be pressed into the exchangeable holder (4) with a very slight allowance adapted to the diameter of the cutting tool (5) that is to be prepared.

4. Apparatus (1) according to any one of the preceding claims, characterized in that the exchangeable holder (4) is insertable into a, preferably central, bore (11) in the grinding disk receptacle (3), preferably in the receiving collar for the grinding disk (14), or of a different processing device.

5. Apparatus (1) according to claim 4, characterized in that the exchangeable holder (4) comprises an outer thread (6) that can be screwed into the bore (11), which is provided with an inner thread, in the grinding disk receptacle (3) or of a different processing device.

6. Apparatus (1) according to claim 4, characterized in that the exchangeable holder (4) can be pressed or inserted into a, preferably central, bore (11) in the grinding disk receptacle (3), or of a different processing device, and is held there in a rotationally fix fashion.

7. Apparatus (1) according to any one of the preceding claims, characterized in that a guide bushing (12) is arranged in the region of the exchangeable holder (4) for the grinding body (2), via which long-projecting asymmetrical cutting tools (13), preferably deep-drilling tools, single-lip drills, helical drills or the like, having a great length:diameter ratio, can be guided and prepared, wherein the guide bushing (12) is in particular arranged relative to the exchangeable holder (4) - preferably on the exchangeable holder (4) in a prolongation of the exchangeable holder (4) - in such a way that the guide bushing (12) guides and supports the long-projecting cutting tool (13) in front of the region of the machining of the grinding body (2).

8. Apparatus (1) according to any one of the preceding claims, characterized in that electrical conductor paths and / or sensor elements, which provide information on the progression of the cutting edge preparation, are introducible in the exchangeable holder (4), wherein in particular the sensor elements are equipped with accumulators, which are integrated in the exchangeable holder (4) and can be charged, while not in use, in the grinding disk magazine or externally.

9. Apparatus (1) according to any one of the preceding claims, characterized in that the grinding body (2) comprises abrasive particles, in particular of silicon carbide, aluminum dioxide or diamond, and is successively completely machinable by the cutting tools (5) which are to be prepared.

10. Apparatus (1) according to claim 9, characterized in that the grinding body (2) comprises a mixture of fine and / or coarse abrasive particles, wherein a distribution of fine and / or coarse abrasive particles within the grinding body (2) is in particular realized inhomogeneously.

11. Apparatus (1) according to any one of the preceding claims, characterized in that the grinding body (2) comprises sections (21, 22) having differing degrees of hardness of the bonding, in particular radial annulus-shaped sections (21, 22) having differing degrees of hardness, wherein in particular the core (22) of the grinding body (2) has a higher hardness of the bonding than the peripheral region (21) in order to achieve a regular cutting edge rounding due to the elastic deformation of the rotationally symmetrical grinding body (2).

12. Method for a cutting edge preparation of cutting tools (5), in particular of drills or milling tools, in particular of hard-metal cutting tools, wherein during a relative movement the cutting tool (5) interacts in a machining fashion with a flexibly-bonded grinding body (2) which is provided with abrasive particles, the particles of the grinding body (2) influencing the edge geometry of the cutting tool (5), characterized in that the grinding body (2) is adapted with its dimensions substantially to the dimensions of the respective cutting tool (5) that is to be prepared, wherein cylindrical circumferential measurements of the grinding body (2) are substantially adapted to circumferential measurements of the cutting tool (5) that is to be prepared, and wherein the grinding body (2) is pressed, in a rotationally fix fashion, into a bore of an exchangeable sleeve-like holder (4), which is arranged in the region of a processing device, in particular of a tool grinding machine, and in which the grinding body (2) is successively completely machined by the cutting tools (5) which are to be prepared, wherein the grinding body (2) has an outer diameter that is greater than the outer diameter of the cutting tool (5) such that in the cutting edge preparation cutters of the cutting tool (5) come into contact only with the grinding body (2) and not with the exchangeable sleeve-like holder (4), and wherein the grinding body (2) has an axially-extending perforation (15), which is adapted to the cutting tool diameter (5) and within which the cutting tool (5) is not affected by the particles of the grinding body (2).

13. Method according to claim 12, characterized in that the cutting edge preparation is carried out in the same clamping arrangement, directly following a first-time manufacturing of the shape of the cutting tool (5) or following a regrinding of the cutting tool (5), on the same processing device.

14. Method according to any one of claims 12 or 13, characterized in that in the machining of the grinding body (2) a wide range of adaptation of the cutting speeds is achieved by the relative movement of grinding body (2) and cutting tool (5), in particular by the superimposition of the rotation directions and rotation speeds.

15. Method according to claim 14, characterized in that during the machining of the grinding body (2), the grinding body (2) and / or the cutting tool (5) execute rotary movements, wherein in particular a superimposition of the rotary movements of the grinding body (2) and / or of the cutting tool (5) permits selective roundings and / or tiltings of the cutting edge of the cutting tool (5), and / or permits a production of asymmetrical cutting edge profiles and / or of cutting edge profiles which are variable over the tool diameter.

16. Method according to claim 14, characterized in that during the cutting edge preparation the cutting tool (5) that is to be prepared executes the necessary translational and rotary movements.

17. Method according to any one of claims 12 to 16, characterized in that the grinding body (2) creates variable roundings over the cutting region of the cutting tools (5) by means of sections having different degrees of hardness of the bonding.

18. Method according to any one of claims 12 to 17, characterized in that due to an axially-extending perforation (15), which is adapted to the cutting tool diameter (5) and within which the cutting tool (5) is not affected by the particles of the grinding body (2), the grinding body (2) does not subject the axial regions of the cutting tool (5), in particular the main cutters of a drilling tool, to a cutting edge preparation, in particular to a rounding of the transverse cutter.

19. Method according to any one of claims 12 to 18, characterized in that the grinding body (2) has outer measurements which are adapted to the cutting tool diameter (5), such that only selected regions of the cutters of the cutting tool (5) are subjected to a cutting edge preparation.

20. Method according to any one of claims 12 to 19, characterized in that the cutting edge preparation is carried out on new tools (5) or on cutting tools (5) which were reground and are therefore already coated with a hard-metal layer on certain functional surfaces.

21. Method according to any one of claims 12 to 20, characterized in that for the cutting edge preparation, the cutting tool (5) having main cutters and secondary cutters, in particular milling tools (20), frictional tools (18) and / or sequential-drilling tools (19), successively machines - by means of its main cutters, respectively secondary cutters - respectively corresponding grinding bodies (2) which have different characteristics and are allocated one by one.

22. Grinding body (2) for an execution of the method according to claim 12, characterized in that the cylindrical circumferential measurements of the grinding body (2) are substantially adapted to the circumferential measurements of the cutting tool (5) that is to be prepared.

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