Method for machining a cutting tool, and machining device for carrying out the method

Abstract

The invention relates to a method for machining a cutting tool (1,21) and to a machining device (50) for carrying out the method. The cutting tool (1, 21) has a cutting tool body (2, 22) and at least one cutting insert (3, 4, 5, 23) which is secured to the cutting tool body (2, 22) and has at least one cutting edge (10, 30). As part of the method, a three-dimensional surface of the cutting tool (1, 21) is specified. Cutting edge delimiting surfaces (11a, 12a, 31a, 32a) are determined therefrom, said cutting edge delimiting surfaces forming the surface of the cutting insert (3, 4, 5, 23) and being arranged adjacently to a cutting edge (10, 30) of the cutting insert (3, 4, 5, 23). The machining device (50) is controlled using said cutting edge delimiting surfaces (11a, 12a, 31a, 32a) and removes material from the cutting insert (3, 4, 5, 23) in a controlled manner, wherein a collision between the cutting tool and a material removing device (56) of the machining device (50) is prevented.

Description

[0001] Title: Method for machining a cutting tool and

[0002] Processing device for carrying out the process

[0003] DESCRIPTION

[0004] The invention is based on a method for machining a cutting tool which has a cutting tool body and at least one cutting insert fastened to the cutting tool body and having at least one cutting edge.

[0005] Cutting tools include machining tools for metal-cutting manufacturing processes and tools for cutting. They typically have a shank and a cutting part. The shank serves to hold the cutting tool, for example, in a machine interface in machine tools. The shank is equipped with the cutting part. The cutting part has at least one cutting edge with which the cutting tool interacts with a workpiece to be machined, thereby removing material from the workpiece. Such cutting tools include, for example, milling cutters, drills, reamers, chisels, scrapers, planes, and saws. The cutting tool can be a solid tool made entirely of a single material. Alternatively, the cutting part can also have an insert surrounding the cutting edge, whereby the insert is made of a different material than the shank.Cutting tools are subject to considerable mechanical and thermal stress at their point of use due to the forces acting on them and the resulting temperatures. These include mechanical friction, oxidation, and abrasion, as well as, especially at high machining speeds, diffusion and scaling. This leads to wear of the cutting tool in the area of ​​the cutting edge.

[0006] To improve the wear resistance of cutting tools and increase tool life, cutting tools are coated with a material around the cutting edge that is harder than the rest of the cutting tool body. For this purpose, a cutting tool with a cutting insert can either have the cutting insert coated with a hard coating, or the entire cutting insert can be made of a hard material. Examples of such hard or ultra-hard materials include diamond, such as polycrystalline diamond (PCD), single-crystal diamond, crystalline diamond, or diamond from chemical vapor deposition (CVD), amorphous carbon (diamond-like carbon DLC), cubic boron nitride (CBN), titanium, or ceramic.If the cutting insert is equipped with a coating made of hard material, this can be applied to the cutting insert using chemical vapor deposition (CVD), for example.

[0007] Cutting inserts are typically brazed directly onto the tool body for attachment. While this connection is characterized by high strength, brazing processes are not precise enough to ensure exact positioning of the cutting inserts on the cutting tool body. In addition, the cutting inserts may exhibit certain inaccuracies in their shape, length, width, depth, or a possible curvature of their surfaces. These inaccuracies in the cutting inserts and inaccurate positioning of the cutting inserts on the cutting tool body result in the associated cutting tool not meeting the specified tolerances and being of poor quality. Therefore, a cutting tool must be reworked after the cutting inserts have been brazed on.During this post-processing, material is removed from the cutting inserts in a targeted manner so that, in particular, the cutting edge and the surfaces bordered by the cutting edge meet the specifications. This is achieved using a machining device that has a fixing device that holds and secures the cutting tool, a material removal device that removes material from the cutting tool, and a movement device. The movement device moves the cutting tool held in the fixing device and the material removal device relative to one another for targeted material removal. The material removal device can be equipped, for example, with a grinding wheel, a laser for generating a laser beam, or with a device for electrical discharge machining (EDM).

[0008] Before the cutting inserts brazed onto the tool body can be reworked using the machining fixture, the precise position of each cutting insert in three dimensions relative to the known references of the cutting tool must be determined. Furthermore, it must be determined whether the surfaces are flat or curved. If the cutting tool is designed as a rotary tool that rotates around a geometric cutting tool rotation axis during use, the geometric cutting tool rotation axis can, for example, serve as a reference. Another reference can be a top surface of the cutting tool or a bottom surface of the cutting tool.

[0009] From the detected position, orientation, and shape of the cutting inserts, the path along which the material removal device must be moved relative to the cutting tool is determined in order to achieve the material removal on the cutting inserts required for post-processing. It is known to detect the position of the brazed cutting inserts on a cutting tool using a mechanical measuring probe. This measuring probe is arranged on the machining device for this purpose. Based on the type and shape of the cutting tool and the type and number of cutting inserts on the cutting tool, the measuring probe must be moved relative to the cutting tool so that it detects the position of the surface relative to a reference value, such as the geometric cutting tool rotation axis, at at least three measuring points on each cutting insert. The measuring probe is usually controlled by a computer, e.g. CNC.The software must be created and specified by the responsible operator based on the type, quantity, and approximate position of the cutting inserts. While the operator can rely on technical specifications and drawings of the cutting tool, these specifications do not include the inaccuracies resulting from brazing the cutting inserts. The operator must therefore enter the details into the control system so that the measuring probe can be moved to the measuring points of the cutting inserts. This is particularly time-consuming for cutting tools with a large number of cutting inserts. Furthermore, there is a risk of errors being made when entering the details into the control system.

[0010] The invention is based on the object of providing a method which facilitates the post-processing of cutting inserts after soldering onto a cutting tool, wherein the post-processing is carried out automatically and a collision of the processing device with the cutting tool is avoided.

[0011] This object is achieved by a method having the features of claim 1 and by a machining device having the features of claim 22. The method is characterized by the following method steps: a) Target data of the cutting edge are specified, which are referred to as cutting edge target data. This data comprises data on at least one of the following properties of the cutting edge: cutting edge position relative to a cutting tool-specific coordinate system, cutting edge geometry, cutting edge profile relative to the cutting edge-specific coordinate system. The cutting tool-specific coordinate system comprises coordinate axes that extend through the cutting tool and a zero point in or on the cutting tool. When the cutting tool is moved, the cutting tool-specific coordinate system is moved along with it.The coordinates of the cutting edge position and the coordinates of the cutting edge path therefore do not change in this cutting tool-specific coordinate system. The cutting edge target data defines the details that the cutting edge of the cutting insert arranged on the cutting tool must have and that are to be achieved with the machining, provided the cutting edge does not already meet the relevant details. b) Geometric material removal device data are specified, which include the shape and size of the material removal device. The dimensions of the material removal device are taken into account during machining. c) The cutting tool is fixed in the fixing device.d) A 3-dimensional surface of the cutting tool arranged in the fixing device of the machining device is specified, at least in those sections of the cutting tool that encompass the cutting insert and form an outer surface of the cutting tool. This surface is defined as the 3-dimensional cutting tool surface. e) Then, from the 3-dimensional cutting tool surface, those subregions that form a surface of the cutting insert and are arranged adjacent to the cutting edge are determined. These surfaces are defined as cutting edge boundary surfaces. The cutting insert has at least two cutting edge boundary surfaces. These can be, for example, a flank surface and a rake surface of the cutting edge of the cutting insert.f) Real cutting edge data is determined from the cutting edge boundary surfaces, whereby the real cutting edge data includes at least the property contained in the target cutting edge data. While the target cutting edge data describes the desired state of the cutting edge, the real cutting edge data concerns the actual state of the cutting edge. In order to be able to compare the actual state with the desired state, the real cutting edge data contains details on the same properties as the target cutting edge data. g) The real cutting edge data is then compared with the target cutting edge data. It is determined whether the real cutting edge data match the target cutting edge data. A specified tolerance is taken into account. If a match is found, the cutting edge does not need to be machined.h) If a deviation between the actual cutting edge data and the target cutting edge data is greater than a specified tolerance, the cutting insert is machined as follows: i) A movement path of the movement device is determined from the specified material removal device data and the difference between the actual cutting edge data and the target cutting edge data in such a way that, during a relative movement of the cutting tool and the material removal device and simultaneous material removal on the cutting tool with the material removal device, the cutting edge is formed with the target cutting edge data within the specified tolerance and a collision between the cutting tool and the material removal device is excluded. For this purpose, the difference between the actual cutting edge data and the target cutting edge data and the material removal device data are processed.The trajectory determines how the material removal device must move relative to the cutting edge boundary surfaces so that the material removal device removes material from the cutting insert in a targeted manner, so that the cutting tool meets the specified parameters with cutting edge target data after machining. j) Finally, the material removal device and the.

[0012] The movement device is controlled, and material is removed from the cutting insert. This involves targeted material removal from the cutting insert so that, after material removal is complete, the cutting insert meets the cutting insert target data within specified tolerances, and the machining device does not contact the cutting tool in an undesirable manner.

[0013] In principle, the cutting insert not only has surfaces that are part of the surface of the cutting tool and are located adjacent to the cutting edge of the cutting insert. For example, the cutting insert also includes those surfaces where the cutting insert is brazed to the cutting tool body. It is assumed that those surfaces of the cutting insert that are part of the surface of the cutting tool and that are adjacent to the cutting edge of the cutting insert are particularly important for the quality of the cutting tool, which is why inspection and reworking in this area is of particular importance. If necessary, reworking can of course also be performed on surfaces of the cutting insert that are not adjacent to the cutting edge.Typically, no post-processing takes place in those sections of the cutting insert where the cutting insert is brazed to the cutting tool body, as these sections are not exposed and therefore do not directly influence the properties of the cutting edge, and machining in these sections could lead to the cutting insert becoming detached from the cutting tool body. In addition to these fastening sections and the surfaces that define the cutting edge, the cutting insert may have other surfaces that can be machined. The 3-dimensional cutting tool surface is specified in such a way that no data needs to be entered manually into the machining device. The 3-dimensional cutting tool surface can, for example, be generated using already known CAD data of the cutting tool and entered into the machining device.This CAD data can contain the surface of the cutting tool in two dimensions or in three dimensions. For example, the surface of the cutting tool body and the surface of the cutting insert can be specified in three dimensions. The three-dimensional surface of the cutting tool is then determined from this data. In this case, the 3-dimensional cutting tool surface corresponds to the theoretical geometric surface of the cutting tool generated from the CAD design of the cutting tool, or is part of it. Alternatively, the 3-dimensional surface can be generated using a surface scanner based on the cutting tool clamped in the fixing device and entered into the fixture. In this case, the 3-dimensional cutting tool surface corresponds to the actual surface of the cutting tool after the cutting inserts have been brazed on.In both cases, the surface data does not need to be entered into the system manually. The process is therefore significantly less time-consuming and less error-prone for the user.

[0014] By evaluating the 3-dimensional cutting tool surface, those subregions that form a surface of the cutting insert and are arranged adjacent to a cutting edge are determined. These subregions are characterized by having a specific orientation relative to a reference value of the cutting tool, for example, to the geometric cutting tool rotation axis, to the underside or the top side of the cutting tool. This property of the surfaces of the cutting inserts is utilized in their determination. Using the method according to the invention, the cutting edge boundary surfaces are determined regardless of how and in what manner the 3-dimensional cutting tool surface is specified. No data or information needs to be entered by the user for this purpose.

[0015] By evaluating the 3-dimensional cutting tool surface and determining the cutting edge boundary surfaces, the position, orientation, possible curvature of the surface, and the length, width, or depth of the cutting inserts are determined. If necessary and desired, measuring points can be defined on the cutting edge boundary surfaces at which the surface of the cutting inserts is scanned. The cutting edge boundary surfaces determined from the 3-dimensional cutting tool surface are adapted to the data obtained during scanning.

[0016] The cutting edge boundary surfaces, possibly with adjustment using scanning data, are used to determine how the material removal device must be moved relative to the cutting tool in order to remove material from the cutting inserts in a targeted manner. This allows for post-processing of the brazed cutting inserts and allows the cutting tool to subsequently meet the specifications regarding the position, alignment, and contour of the cutting edge and the surfaces defined by the cutting edge within certain tolerances. When determining the trajectory, the geometry and dimensions of the material removal device and the cutting tool are taken into account, ensuring that the relative movement of the material removal device and the cutting tool is collision-free.

[0017] The following surfaces can be assigned to the cutting tool:

[0018] 1. A theoretical 3-dimensional geometric surface of the cutting tool resulting from its design; if the cutting tool is designed using CAD, the theoretical 3-dimensional geometric surface of the cutting tool can be derived from the CAD data. This surface may not include any inaccuracies resulting from the manufacturing of the cutting insert and the brazing of the cutting insert. Actual 3-dimensional surface of the cutting tool after brazing of the cutting insert; This surface includes any inaccuracies resulting from the manufacturing of the cutting insert and the brazing of the cutting insert. This surface can be determined, for example, using a surface scanner.which covers the entire surface of the cutting tool; Alternatively, this surface can be determined using the data resulting from section 1 and a subsequent scanning of the surfaces of the cutting insert at individual specific measuring points on the surface of the cutting insert, whereby the surface resulting from section 1 is adapted to the scanning data resulting from the scanning at the measuring points; The number of measuring points in this case is significantly smaller than the number of points at which the surface of the cutting tool is scanned by means of a surface scanner; It is also possibleto adapt the surface determined with the surface scanner to the scanning data resulting from the scanning at the measuring points; this can increase the accuracy if necessary. The 3-dimensional cutting tool surface according to claim 1 can be derived from the theoretical 3-dimensional surface according to paragraph 1 or from the actual 3-dimensional surface according to paragraph 2. Cutting edge boundary surfaces determined from the 3-dimensional surface of the cutting tool: the cutting edge boundary surfaces can be determined from the theoretical geometric 3-dimensional surface of the cutting tool according to section 1 above or from the actual 3-dimensional surface of the cutting tool after brazing the cutting insert according to section 2 above. If the cutting edge boundary surfaces are determined from the theoretical geometric 3-dimensional surface of the cutting tool according to section 1 above,Several measurement points should be determined on the resulting cutting edge boundary surfaces, and the surface of the cutting tool arranged in the fixing device should be measured at these measurement points using a measuring probe. This serves to adapt the theoretical cutting edge boundary surfaces to reality. The cutting edge boundary surfaces are adjusted in such a way that the scanning data acquired with the measuring probe lie on the cutting edge boundary surfaces. This,

[0019] Cutting edge boundary surfaces have the real cutting edge data.

[0020] 4. Reworked cutting edge boundary surfaces: after

[0021] Upon completion of material removal using the method according to the invention, the cutting edges and the adjacent cutting edge boundary surfaces of the cutting tool should meet the specifications applicable to the cutting edge and the cutting edge boundary surfaces within specified tolerances. In this case, the cutting edge has the target cutting edge data.

[0022] In the method according to the invention, the 3-dimensional cutting tool surface is specified according to Section 1 above or according to Section 2 above, and the cutting edge boundary surfaces are determined from this according to Section 3 above. It is assumed that these cutting edge boundary surfaces correspond to the corresponding real surfaces on the cutting tool clamped in the fixing device and to be machined, and that they have the actual cutting edge data. Based on these cutting edge boundary surfaces, the movement device and the material removal device are controlled so that material is removed from the cutting insert in a targeted manner. The goal is that the cutting edge boundary surfaces reworked in this way meet the criteria specified in Section 4 above and the target cutting edge data after machining.If the cutting edge boundary surfaces meet the criteria, the cutting edge also meets the specified criteria.

[0023] The data required for post-processing is automatically determined from the cutting tool surface, eliminating the need for the operator to manually input data or determine measurement data. This significantly simplifies post-processing. Since input errors are eliminated, post-processing is also more precise.

[0024] Before being brazed to the cutting tool body, the cutting insert can be dimensioned such that sufficient material is always available to form a cutting edge on the cutting tool that meets the specified criteria in the event of necessary material removal. In this case, the cutting insert protrudes beyond the cutting tool body and a specified cutting tool geometry. If necessary, the cutting edge is only created on the cutting tool during the implementation of the method according to the invention.

[0025] To avoid unwanted collisions between the material removal device and the cutting tool, the geometric data of the material removal device, which includes the shape and size of the material removal device, are taken into account when determining the trajectory. This can be done using known calculation methods for collision avoidance. The specified data of the cutting tool and the material removal device are taken into account. Known calculation methods for collision avoidance can be considered. For example, Minkowski addition is used for this purpose.

[0026] According to an advantageous embodiment of the invention, the cutting edge boundary surfaces are used to determine where and how much material must be removed from the cutting insert so that the cutting insert meets specified parameters in the area of ​​its cutting edge, taking into account specified tolerances. The movement device and / or the material removal device are controlled such that the material removal device removes this material. The parameters include, for example, the orientation and / or position and / or size and / or curvature of the cutting edge boundary surfaces. Target values ​​and tolerances can be specified for this purpose.

[0027] According to a further advantageous embodiment of the invention, the cutting tool is a rotary cutting tool, which is rotated about a geometric cutting tool rotation axis during use. The geometric cutting tool rotation axis corresponds to the axis about which the cutting tool is rotated at its later location of use. Advantageously, the cutting tool designed as a rotary tool is received in the fixing device in such a way that it is rotated about the geometric cutting tool rotation axis with the movement device.

[0028] According to a further advantageous embodiment of the invention, the orientation of the cutting edge boundary surfaces is determined relative to the geometric cutting tool rotation axis. This takes advantage of the fact that the cutting inserts generally have a specific orientation relative to the geometric cutting tool rotation axis. This orientation is a prerequisite for the cutting inserts to achieve the desired material removal at the subsequent location of the cutting tool when the cutting tool is rotated about the cutting tool rotation axis.

[0029] According to a further advantageous embodiment of the invention, the position of the cutting edge boundary surfaces is determined relative to the geometric cutting tool rotation axis. This takes advantage of the fact that the cutting inserts generally have a specific position relative to the geometric cutting tool rotation axis.

[0030] According to a further advantageous embodiment of the invention, the position of the cutting edge limiting surface is determined relative to a front face of the cutting tool. If the cutting tool is designed as a rotary tool that is rotated about a cutting tool rotation axis at the point of use and that extends along the cutting tool rotation axis from a first end to a second end, the front face is preferably a surface of the cutting tool at the first end or at the second end that is perpendicular to the cutting tool rotation axis.

[0031] According to a further advantageous embodiment of the invention, several measuring points are determined on at least one cutting edge boundary surface. At these measuring points, the coordinates corresponding to the cutting edge boundary surface are recorded from a predefined coordinate system using a coordinate measuring device. The coordinate measuring device can be a measuring probe, for example. The coordinate measuring device can record the coordinates of the cutting edge boundary surface assigned to the measuring points with contact or without contact. The determination of the measuring points takes advantage of the fact that the cutting edge boundary surface is derived from the 3-dimensional cutting tool surface and that the measuring points for scanning can be determined automatically and without user intervention from the cutting tool surface.A relative movement between the coordinate measuring device and the cutting tool can be achieved using the movement device of the machining device. The relative movement occurs in such a way that the coordinate measuring device records the coordinates of the cutting edge boundary surface at the specified measuring points without the coordinate measuring device undesirably touching or colliding with the cutting tool. The coordinate measuring device can be designed as a mechanical measuring probe and record the surface of the cutting inserts at the measuring points by contact. Alternatively, the coordinate measuring device can record the coordinates non-contact. In this case, the surface at the measuring points can be recorded optically, for example. Advantageously, at least three measuring points are determined for each cutting insert.In contrast to the surface scanner, the coordinate measuring device measures the surface of the cutting tool only at a small number of measuring points on at least one cutting edge boundary surface. The coordinate measuring device is not necessarily designed to measure the entire surface of the cutting tool, as is the case with the surface scanner.

[0032] According to a further advantageous embodiment of the invention, the cutting edge boundary surface is adjusted taking into account the recorded coordinates of the measuring points on the cutting edge boundary surface, such that these coordinates lie on the adjusted cutting edge boundary surface. The coordinates are part of the adjusted cutting edge boundary surface. In this way, the cutting edge boundary surfaces can be corrected. For example, the 3-dimensional cutting tool surface, which is determined from CAD data or based on a surface scan, can be modified so that the scan data lies on the 3-dimensional cutting tool surface. Inaccuracies or deviations from the actual surface are thus taken into account.

[0033] According to a further advantageous embodiment of the invention, the recorded coordinates of the measuring points are used to check whether the cutting edge boundary surfaces are curved or flat. If, for example, it is determined that one of the cutting edge boundary surfaces has a curvature that leads to an undesirable curvature of the cutting edge, the corresponding cutting edge boundary surface can be smoothed and converted into a flat surface through post-processing, so that the cutting edge has a specified straight line. If the cutting edge boundary surfaces have a curvature according to the specification, more than three measuring points must be specified. If the cutting edge also has a curvature according to the specification, the movement device and / or the material removal device must be controlled accordingly so that the cutting edge meets the specifications with regard to the curvature after post-processing.

[0034] According to a further advantageous embodiment of the invention, the coordinate measuring device is moved relative to the cutting tool with the movement device in such a way that the coordinates of the measuring points are recorded and the relative movement takes place free of collisions between the cutting tool and the coordinate measuring device.

[0035] According to a further advantageous embodiment of the invention, the machining path extends into an area that extends beyond the edge of at least one cutting edge boundary surface. This ensures that the material removal device processes the entire cutting edge boundary surface.

[0036] According to a further advantageous embodiment of the invention, a starting point and an end point for the material removal on the cutting edge boundary surface are determined based on the cutting edge boundary surfaces. Machining of the cutting insert with the material removal device begins at the starting point. Machining of the cutting insert is terminated at the end point. The starting point and end point are two spatially defined points on the cutting edge boundary surfaces. Progressive machining of the cutting edge boundary surface takes place between the starting point and the end point. Advantageously, the material removal device is guided along the machining path from the starting point to the end point.

[0037] According to a further advantageous embodiment of the invention, the material removal device comprises a laser. A laser beam generated by the laser is specifically directed onto the surface of the cutting insert. The laser beam generates such a high energy density on the surface of the cutting insert that the material of the cutting insert locally vaporizes or sublimates. The material removal is also referred to as laser ablation or laser evaporation. The material can, for example, be removed in layers across a large area. The laser is advantageously pulsed.

[0038] According to a further advantageous embodiment of the invention, the laser is equipped with an optical deflection device that moves the laser beam relative to the cutting tool in addition to the movement device. This allows two movements of the laser beam relative to the cutting tool to be generated: a first movement by means of the movement device and a second movement by means of the laser's deflection device. The first and second movements are superimposed. As a rule, higher speeds can be achieved with the optical deflection device than with the movement device. The optical deflection device can be, for example, a laser scanner.

[0039] According to a further advantageous embodiment of the invention, the material removal device comprises a grinding wheel. In this case, the material removal takes place by means of a grinding process.

[0040] According to a further advantageous embodiment of the invention, the material removal device removes material using electrical discharge machining (EDM). According to a further advantageous embodiment of the invention, the cutting insert consists of an ultra-hard material such as polycrystalline diamond (PCD), cubic boron nitride (CBN), diamond from chemical vapor deposition (CVD), single-crystal diamond, or ceramic. In the case of a coating, this can be applied by CVD. Alternatively, diamond-like amorphous carbon (DLC) can also be used.

[0041] According to a further advantageous embodiment of the invention, the 3-dimensional cutting tool surface is determined from the specified CAD data of the cutting tool. Through the computer-aided design and manufacture of the cutting tool with at least one cutting insert, a geometric model of the cutting tool is available as a digital data set. The CAD data contains this digital data set. The theoretical geometric 3-dimensional cutting tool surface can be determined from the CAD data by calculation. Since the CAD data originate from the geometric model, it does not contain the inaccuracies resulting from the manufacture of the cutting inserts and from the soldering of the cutting inserts to the cutting tool body. Therefore, it does not represent reality in an identical manner.For this reason, it may be advantageous to determine measuring points on the surface of the cutting inserts, to detect the actual real cutting edge boundary surfaces by scanning the measuring points using a measuring probe and to adapt the cutting edge boundary surfaces to the scanning data.

[0042] According to a further advantageous embodiment of the invention, the 3-dimensional cutting tool surface is generated using a surface scanner. The surface scanner is equipped with one or more sensors that scan or measure the cutting tool in a systematic and regular manner. A large number of individual measurements generate an overall image of the cutting tool. The measured values ​​recorded by the sensors are converted into digital data and processed by a computer. From this data, the 3-dimensional cutting tool surface can be determined by calculation. The 3-dimensional cutting tool surface recorded with the surface scanner may very well represent the actual surface of the cutting tool. In this case, it is not absolutely necessary to define measuring points on the surface of the cutting insert and to measure the surface at these measuring points with a measuring probe.However, additional scanning with a measuring probe can be performed for inspection purposes. For example, if such an inspection reveals that the scanned data determined with the measuring probe is part of the 3-dimensional cutting tool surface captured with the surface scanner, no further inspection is required on the remaining surfaces of the cutting insert. However, if deviations are detected, the inspection can be continued. Such an inspection by scanning with a measuring probe is generally useful if the cutting tool surface captured with the surface scanner does not meet the required accuracy.

[0043] According to a further advantageous embodiment of the invention, a grid of partial surfaces is placed over the 3-dimensional cutting tool surface. For each partial surface, the orientation relative to a reference value, for example, the geometric cutting tool rotation axis, is determined. From this, the cutting edge boundary surfaces are determined.

[0044] According to a further advantageous embodiment of the invention, the partial areas are triangles. Alternatively, the partial areas can also be quadrilaterals or other polygons.

[0045] According to a further advantageous embodiment of the invention, the orientation of any two adjacent partial surfaces is compared with each other. From this, the cutting edge boundary surfaces are determined. This takes advantage of the fact that adjacent partial surfaces with the same or a similar orientation belong to the same cutting edge boundary surface.

[0046] According to a further advantageous embodiment of the invention, the collision-free trajectory is determined using Minkowski addition. Other calculation methods for determining a collision-free machining trajectory can be used alternatively.

[0047] The processing device according to the invention is characterized in that it is equipped with a control device which controls the fixing device, the movement device and the material removal device in such a way that they carry out the method according to the invention.

[0048] According to a further advantageous embodiment of the invention, the processing device is equipped with a coordinate measuring device, which is also controlled by the control device.

[0049] Further advantages and advantageous embodiments of the invention can be found in the following description, the drawings and the claims.

[0050] drawing

[0051] The drawings illustrate exemplary embodiments of the subject matter of the invention. They show:

[0052] Figure 1 shows a perspective view of a first embodiment of a cutting tool which is machined using the method according to the invention, representation based on CAD data, Figure 2 shows a perspective view of the cutting tool according to Figure 1 based on data which were determined using a surface scanner, representation using triangles

[0053] Figure 3 Representation according to Figure 2 using different shades of grey,

[0054] Figure 4 perspective view of the cutting tool according to Figures 1, 2 and 3 after completion of the post-processing with the method according to the invention,

[0055] Figure 5 Representation of the cutting tool according to Figure 1 , with the outer cutting tool geometry marked,

[0056] Figure 6 Representation of the cutting tool according to Figure 1 with the machining path of a material removal device,

[0057] Figure 7 Representation of the cutting tool according to Figure 1 with marking of the measuring points at which the surface of a cutting insert is scanned with a measuring probe,

[0058] Figure 8 Comparison of the CAD data and the data determined with the surface scanner for the cutting tool according to Figures 1 to 7,

[0059] Figure 9 perspective view of a second embodiment of a cutting tool which is machined using the method according to the invention, representation based on CAD data,

[0060] Figure 10 perspective view of the cutting tool according to Figure 9 based on data obtained by means of a surface scanner,

[0061] Figure 11 Detail from Figure 9, Figure 12 Detail from Figure 11 ,

[0062] Figure 13 Part of the cutting tool according to Figures 9 and 10 after completion of the post-processing with the method according to the invention,

[0063] Figure 14 Processing device for carrying out the method.

[0064] Description of the embodiments

[0065] Figures 1 to 8 show a first cutting tool that is machined using the method according to the invention. The machining device with which the machining is carried out is shown in Figure 14. Figures 1 and 2 show the cutting tool before machining. Figure 1 corresponds to a representation of the CAD data of the cutting tool, which are specified by the design of the cutting tool using CAD. Figure 2 corresponds to a representation of data that was determined using a surface scanner. The cutting tool 1 comprises a cutting tool body 2, on which a total of six cutting inserts 3, 4, 5 are arranged. The cutting tool is a rotary tool that is rotated at its location of use about a geometric cutting tool rotation axis 6. The cutting tool is not shown in full in the drawing.A shank 7, which serves to hold the cutting tool 1 in a machine (not shown), is only partially shown for reasons of clarity. No cutting inserts are arranged in the part of the cutting tool not shown. Therefore, no machining using the method takes place in the part of the cutting tool not shown. The section of the cutting tool 1 in which the cutting inserts 3, 4, 5 are arranged on the cutting tool body 2 is defined as the 3-dimensional cutting tool surface. This 3-dimensional cutting tool surface is visible in Figures 1 and 2 at least insofar as it faces the viewer. The parts of the 3-dimensional cutting tool surface facing away from the viewer are concealed by the cutting tool body 2 in Figures 1 and 2.

[0066] The cutting inserts 3, 4, 5 are arranged offset relative to the cutting tool rotation axis. The two first cutting inserts 3 are located at one end 8 of the cutting tool. They are arranged on the cutting tool body 2 offset by 180° from one another and inclined by an angle α with respect to the cutting tool rotation axis. The two second cutting inserts 4 are arranged at a distance from the end 8 and from the two first cutting inserts 3 in the axial direction relative to the cutting tool rotation axis 6. They are mounted on the cutting tool body offset in the axial direction from the first cutting inserts 3. The angular distance between the two second cutting inserts is also 180°. The two third cutting inserts 5 are located between the two first and second cutting inserts 3, 4 in terms of their axial position and their angular position.In the drawing, only one of the two third cutting inserts 5 is visible, since the other third cutting insert 5 is covered by the cutting tool body 2.

[0067] The first, second and third cutting inserts 3, 4, 5 are brazed onto the cutting tool body 2. After brazing, the cutting inserts 3, 4, 5 initially protrude radially outwards beyond the cutting tool body 2. Figures 1 and 2 show the cutting tool after the cutting inserts 3, 4, 5 have been brazed on. In particular, the section protruding radially beyond the cutting tool body is clearly visible in the case of the first cutting inserts 3 and the second cutting inserts 4. Figure 1 shows a representation of the cutting tool 1 before machining using the method, wherein the representation is based on CAD data. This CAD data results from the computer-aided design of the cutting tool. The 3-dimensional cutting tool surface, which comprises the cutting inserts 3, 4, 5, is shown.

[0068] Figure 2 shows a representation of the cutting tool 1 before machining using the method, the representation being based on data acquired using a surface scanner. This surface scanner is shown in Figure 14 with the reference number 59. The surface scanner scans the surface of the cutting tool 1 from all sides in the sections in which the cutting inserts 3, 4, 5 are arranged. This results in the 3-dimensional cutting tool surface, which is essential for carrying out the method. According to Figure 2, the surface of the cutting tool 1 was scanned in precisely the section of the cutting tool 1 that is also shown in Figure 1 based on the CAD data. The surface scanner produces a number of surface points. These are connected to one another in Figure 2 by lines to form triangles.Figure 3 shows an alternative representation based on the same number of surface points as Figure 2, but instead of triangles, different gray levels are shown. The shape of cutting tool 1 is more clearly visible in this representation than in Figure 2.

[0069] Figure 4 shows the cutting tool 1 with the cutting inserts 3, 4, 5, wherein the cutting inserts meet predetermined criteria with regard to the position and course of their cutting edges 10. The cutting inserts 3, 4, 5 protrude significantly less radially outwards beyond the cutting tool body 2. By way of example, the second cutting insert 4 shows that the cutting edge 10 delimits a first cutting edge boundary surface 11 and a second cutting edge boundary surface 12. The same applies to the first cutting inserts 3 and the third cutting inserts 5. Figure 5 shows the cutting tool 1 according to Figures 1 and 2, wherein the outer geometry 13 of the cutting tool, which is defined by the predetermined course of the cutting edges 10 of the cutting inserts 3, 4, 5, is marked by a line in the region of the first cutting insert 3 and the second cutting insert.From this illustration, it can be seen that the area of ​​the cutting inserts 3, 4, 5 that protrudes beyond the outer geometry 13 of the cutting tool 1 must be removed. In particular, remachining must be performed on a first cutting edge boundary surface 11a and / or a second cutting edge boundary surface 12a so that they correspond within tolerances to the first cutting edge boundary surface 11 and the second cutting edge boundary surface 12 according to Figure 4, and the cutting edge 10 thus has the specified profile.

[0070] In order to enable machining of the cutting inserts 3, 4, 5 in the area of ​​the cutting edge boundary surfaces 11a, 12a, the 3-dimensional surface of the cutting tool 1 is specified using the CAD data according to Figure 1 or using the data determined by the surface scanner according to Figure 2. The entirety of this specified data is referred to as the 3-dimensional cutting tool surface. From this 3-dimensional cutting tool surface, those sub-regions are determined that form a surface of a cutting insert 3, 4, 5 and are arranged adjacent to a cutting edge. These are referred to as cutting edge boundary surfaces 11a, 12a. They are obtained by comparing the orientation or position of the surfaces with the cutting tool rotation axis 6 or an end face 9 of the cutting tool. For this purpose, the 3-dimensional cutting tool surface is broken down into a grid of sub-surfaces 14.In the illustration according to Figure 2, the grid with the partial surfaces 14 corresponds to the triangles resulting from the connection of the surface points. For each partial surface 14, the orientation relative to the geometric cutting tool rotation axis 6 is determined. Alternatively or cumulatively, the orientation relative to the end face 9 of the cutting tool can also be determined for each partial surface 14. Partial surfaces 14 that have the same orientation are assigned to a common surface. Cutting edge boundary surfaces 11a, 12a are distinguished from other surfaces of the cutting tool 1 in that they have a very specific, predetermined orientation relative to the cutting tool rotation axis 6 or to the end face 9.

[0071] The cutting edge real data is determined from the cutting edge boundary surfaces. They relate to at least one property of the cutting edge, namely the cutting edge position relative to a cutting tool-specific coordinate system, the cutting edge geometry, or the cutting edge profile relative to the cutting edge-specific coordinate system.

[0072] Cutting edge target data is specified for the cutting tool, which relates to the corresponding property from the set of properties listed above: cutting edge position relative to a cutting-tool-specific coordinate system, cutting edge geometry, and cutting edge profile relative to the cutting-edge-specific coordinate system. The cutting tool shown in Figure 4 has this cutting edge target data.

[0073] The actual cutting edge data are compared with the target cutting edge data. This comparison determines whether and how much material needs to be removed from the recorded cutting edge boundary surfaces 11a, 12a so that the cutting edge 10 has the target cutting edge data and the specified profile with the specified outer geometry 13.

[0074] Material removal device data, which includes the shape and size of the material removal device 56, are specified for the machining device 50 according to Figure 14. The machining path 15 of a material removal device is determined from the comparison of the actual cutting edge data with the cutting edge target data and the material removal device data. This machining path 15 is shown in Figure 6 on the first, second, and third cutting inserts 3, 4, 5. The machining path 15 extends beyond the cutting edge boundary surfaces 11a, 12a, ensuring that the entire cutting edge surface 11a, 12a is machined. The machining path is specified such that the necessary amount of material is removed from the cutting insert without the material removal device colliding with the cutting tool.

[0075] In the present embodiment, the processing machine is a laser processing machine, which is shown in Figure 14. In this case, the material removal device comprises a laser. A laser beam from the laser is directed onto the first cutting edge boundary surface 11a and removes material. For this purpose, the laser beam is guided once or several times along the processing path 15 until the two cutting edge surfaces 11, 12 and the cutting edge 13 are created according to Figure 4. Alternatively, the material removal can also begin starting from the second cutting edge boundary surface 12a. In this case, the processing path can have a different course than that shown in Figure 6.

[0076] If the 3-dimensional cutting tool surface resulting from the CAD data according to Figure 1 does not sufficiently reflect reality or if a check of the 3-dimensional cutting tool surface according to Figure 1, 2 or 3 is desired, measuring points can be determined on at least one cutting edge boundary surface 11a, at which the coordinates of the cutting edge boundary surface are recorded using a coordinate measuring device. In the present case, three measuring points 16 are determined on the first cutting edge boundary surface 11a. Subsequently, the coordinates of the

[0077] The cutting edge boundary surface is recorded at these three measuring points 16. The resulting measurement data is compared with the cutting edge boundary surface 11a at these measuring points 16. In the event of a deviation, the cutting edge boundary surface 11a is corrected and adjusted accordingly so that the coordinates of the measuring points lie on the cutting edge boundary surface 11a. Such a check of the cutting edge boundary surfaces 11a, 12a can also be carried out if the 3-dimensional cutting tool surface is determined using a surface scanner according to Figure 2 or 3. Since the surface scanner already records the surface of the actual cutting tool, it is assumed that in this case a check is only necessary in exceptional cases or for control purposes. The coordinate measuring device is shown in Figure 14 with the reference number 60.

[0078] Figure 8 shows a comparison of the 3-dimensional cutting tool surface 17 determined using CAD data with the 3-dimensional cutting tool surface 18 determined using a surface scanner. In the light gray areas, the 3-dimensional cutting tool surface 18 determined using the surface scanner protrudes beyond the 3-dimensional cutting tool surface 17 determined using CAD data. In the dark gray areas, the situation is exactly the opposite.

[0079] Figures 9 to 13 show a second embodiment of a cutting tool 21 that is machined using the method according to the invention. Figures 9 and 10 show the cutting tool 21 before machining. Figure 9 corresponds to a representation of the CAD data of the cutting tool 21, which are predetermined by the design of the cutting tool using CAD. Figure 10 corresponds to a representation of data that was determined using a surface scanner. The cutting tool 21 comprises a cutting tool body 22 on which a plurality of cutting inserts 23 are arranged. The cutting tool is a rotary tool that is rotated at its location of use about a geometric cutting tool rotation axis 26.In contrast to the first embodiment of a cutting tool according to Figures 1 to 8, in the cutting tool 21 according to the second embodiment, all cutting inserts 23 are arranged at the same axial position relative to the cutting tool rotation axis 26 and with the same orientation relative to the cutting tool rotation axis 26 on the cutting tool body 22.

[0080] For each cutting insert 23 arranged on the cutting tool body 22, criteria for the course and position of a cutting edge 30 of the cutting insert 23 relative to the cutting tool rotation axis 26 of the cutting tool are specified as cutting edge target data. This specified cutting edge 30 is shown in Figure 13. The specified cutting edge 30 delimits a first cutting edge boundary surface 31 and a second cutting edge boundary surface 32. The course and position of the cutting edges 30 of all cutting inserts 23 of the cutting tool 21 predetermine an external geometry 33 of the cutting tool 21. This external geometry 33 is marked by a line in Figures 9 and 10.

[0081] To implement the method, the cutting edge boundary surfaces 31a, 32a of the cutting inserts 23 are determined from the 3-dimensional cutting tool surface of the CAD data according to Figure 9 or the data determined with a surface scanner according to Figure 10, and actual cutting edge data is derived therefrom. These are compared with specified cutting edge target data. Figures 11 and 12 show, as an example, the two cutting edge boundary surfaces 31a and 32a on a cutting insert 23. From the comparison with the specifications for the cutting edge 30, the first cutting edge boundary surface 31, and the second cutting edge boundary surface 32, it can be determined whether material removal must occur and to what extent the material removal must occur.The machining device is controlled based on the data thus determined so that the corresponding material is removed and the cutting edge 30 meets the specifications shown in Figure 13, while avoiding a collision between the cutting tool and the material removal device. The geometry and dimensions of the cutting tool and the material removal device are taken into account. The machining path is defined so that during a relative movement of the cutting tool and the material removal device, they do not come so close that they undesirably touch.

[0082] The determination of the position and orientation of the cutting edge boundary surfaces 31a, 32a from the 3-dimensional cutting tool surface is carried out in accordance with the first embodiment according to Figures 1 to 8.

[0083] Figure 14 shows a processing device 50 for carrying out the method. The processing device is a laser processing device. It comprises a fixing device 51 that receives and fixes a cutting tool 1, a movement device 53 that moves the cutting tool 1 arranged in the fixing device relative to a device base 55, a laser 56 that generates a laser beam 52, and a laser beam deflection device 57 that guides the laser beam 52. In this case, the movement device 53 has three linear axes X, Y, Z and two rotation axes B and C. The rotation axis C ensures rotation of the cutting tool 1 arranged in the workpiece fixing device 51 about a geometric cutting tool rotation axis that extends through the cutting tool. The laser beam deflection device 57 moves and guides the laser beam 52 in three different directions in space.The laser beam 52 is moved relative to the cutting tool 1 along a laser path not shown in Figure 14. A control device 58 controls the fixing device 51, the movement device 53, and the laser beam deflection device 57 in order to carry out the method for machining the workpiece.

[0084] The processing device 50 is further equipped with a surface scanner 59, which detects the surface of the cutting tool 1 arranged in the fixing device 51 and stores the 3-dimensional cutting tool surface determined in this way. This 3-dimensional cutting tool surface is output to the control device 58, which uses this data to determine the cutting edge boundary surfaces of the cutting inserts, compares them with specifications regarding the cutting edges, determines the material to be removed, and controls the laser beam to specifically remove this material from the cutting inserts of the cutting tool 1.

[0085] For control and inspection purposes, the machining device is further equipped with a coordinate measuring device 60 for detecting the surface of the cutting tool 1 arranged in the fixing device at individual measuring points and assigning coordinates of a coordinate system. A check is then carried out to determine whether these detected coordinates lie on the specified cutting edge boundary surface. If this is not the case, the cutting edge boundary surface is corrected so that the coordinates of the measuring points lie on the adjusted cutting edge boundary surface. The coordinate measuring device 60 is controlled and moved in such a way that a collision between the cutting tool and the coordinate measuring device is avoided. A relative movement between the cutting tool 1 and the coordinate measuring device is carried out by the movement device 53.

[0086] All features of the invention can be essential to the invention both individually and in any combination. Reference numbers

[0087] 1 cutting tool

[0088] 2 cutting tool bodies

[0089] 3 First cutting insert

[0090] 4 Second cutting insert

[0091] 5 Third cutting insert

[0092] 6 Cutting tool rotation axis

[0093] 7 shaft

[0094] 8 End

[0095] 9 Front side

[0096] 10 Cutting edge

[0097] 11 First cutting edge boundary surface after machining

[0098] 11a First cutting edge boundary surface before machining

[0099] 12 Second cutting edge boundary surface after machining

[0100] 12a Second cutting edge boundary surface before machining

[0101] 13 External geometry of the cutting tool

[0102] 14 sub-area

[0103] 15 Machining path of a material removal device

[0104] 16 measuring points

[0105] 17 3-dimensional cutting tool shapes determined using CAD data

[0106] surface

[0107] 18 3-dimensional surfaces determined using a surface scanner

[0108] Cutting tool surface

[0109] 21 Cutting tool

[0110] 22 cutting tool bodies

[0111] 23 Cutting insert

[0112] 26 Cutting tool rotation axis

[0113] 30 cutting edge

[0114] 31 First cutting edge boundary surface after machining

[0115] 31a First cutting edge boundary surface before machining

[0116] 32 Second cutting edge limit surface after machining 32a Second cutting edge limit surface before machining

[0117] 33 External geometry of the cutting tool

[0118] 50 processing device

[0119] 51 Fixing device 52 Laser beam

[0120] 53 Movement device

[0121] 55 Fixture base

[0122] 56 lasers

[0123] 57 Laser beam deflection device 58 Control device

[0124] 59 surface scanners

[0125] 60 coordinate measuring device

Claims

CLAIMS Method for machining a cutting tool (1, 21) which comprises a cutting tool body (2, 22) and at least one cutting insert (3, 4, 5, 23) fastened to the cutting tool body (2, 22) and having at least one cutting edge (10, 30), wherein the machining is carried out using a machining device (50) which has - a fixing device (51) receiving and fixing the cutting tool (1, 21), - a material removal device (56) removing material from the cutting insert (3, 4, 5, 23), and - a movement device (53), wherein the movement device (53) moves the cutting tool (1, 21) accommodated in the fixing device (51) and the material removal device (56) relative to each other for targeted material removal, characterized by the following method steps a) specifying cutting edge target data of the cutting edge (10, 30), wherein the cutting edge target data comprise at least one property from the following set: {cutting edge position relative to a cutting tool-related coordinate system, cutting edge geometry, cutting edge profile related to the cutting edge-related coordinate system}, b) specifying geometric material removal device data, which comprise the shape and size of the material removal device (56), c) fixing the cutting tool (1, 21) in the fixing device (51), d) specifying a 3-dimensional surface of the cutting tool (1, 21) arranged in the fixing device (51), at least in those sections of the cutting tool (1, 21) which comprise the cutting insert (3, 4, 5, 23), this surface being defined as a 3-dimensional cutting tool surface (17, 18), e) determining those sub-regions of the 3-dimensional cutting tool surface (17, 18) which comprise a surface of the cutting insert (3, 4, 5, 23) and are arranged adjacent to the cutting edge (10, 30) of the cutting insert (3, 4, 5, 23),wherein these partial areas are defined as cutting edge boundary surfaces (11a, 12a, 31a, 32a), f) determining real cutting edge data from the cutting edge boundary surfaces (11a, 12a, 31a, 32a), wherein the real cutting edge data comprise at least the property contained in the cutting edge target data, g) comparing the real cutting edge data with the cutting edge target data, h) if the deviation between the real cutting edge data and the cutting edge target data is greater than a predetermined tolerance: i) determining a movement path (15) of the movement device (53) from the predetermined material removal device data and the difference between the real cutting edge data and the, Cutting edge target data, such that during a relative movement of the cutting tool (1, 21) and the material removal device (56) and a simultaneous material removal on the cutting tool (1, 21) with the material removal device (56), the cutting edge (10, 30) is formed with the cutting edge target data within the predetermined tolerance and a collision between the cutting tool (1, 21) and the material removal device (56) is excluded, j) controlling the material removal device (56) and the Movement device (53) based on the determined movement path and carrying out the associated relative movement while simultaneously removing material from the cutting insert (3, 4, 5, 23) with the material removal device (56). Method according to claim 1, characterized in that the cutting tool (1, 21) is a rotary cutting tool which, during use, is rotated about a geometric cutting tool rotation axis (6, 26). Method according to claim 2, characterized in that the orientation of the cutting edge limiting surfaces (11a, 12a, 31a, 32a) is determined relative to the geometric cutting tool rotation axis (6, 26). Method according to claim 2 or 3, characterized in that the position of the cutting edge limiting surfaces (11a, 12a, 31a, 32a) is determined relative to the geometric cutting tool rotation axis (6, 26).Method according to one of the preceding claims, characterized in that a plurality of measuring points (16) are determined on at least one cutting edge boundary surface (11 a, 12 a, 31 a, 32 a), and that in the case of the cutting tool (1) arranged in the fixing device (51) at these. Measuring points (16) which correspond to the cutting edge boundary surface (11a, 21a, 31a, 32a) are recorded with reference to a predetermined coordinate system by means of a coordinate measuring device (60).

6. Method according to claim 5, characterized in that the cutting edge boundary surface (11a, 12a, 31a, 32a) is adapted taking into account the coordinates of the measuring points which are determined with the coordinate measuring device (60), such that the detected coordinates of the measuring points lie on the adapted cutting edge boundary surface (11a, 12a, 31a, 32a).

7. Method according to claim 5 or 6, characterized in that the scanning data determined during scanning are used to check whether the cutting edge boundary surfaces (11a, 12a, 31a, 32a) are curved or flat.

8. Method according to one of claims 5 to 7, characterized in that the coordinate measuring device (60) is moved relative to the cutting tool (1, 21) with the movement device (53) in such a way that the coordinates of the measuring points (16) are detected and the relative movement takes place free of collisions between the cutting tool (1, 21) and the coordinate measuring device (60).

9. Method according to one of the preceding claims, characterized in that the machining path (15) extends in a region which extends beyond an edge of at least one cutting edge boundary surface (11a, 12a, 31a, 32a).

10. Method according to one of the preceding claims, characterized in that a starting point and an end point of the material removal on the cutting edge boundary surface (11a, 12a, 31a, 32a) are determined on the basis of the cutting edge boundary surfaces (11a, 12a, 31a, 32a).

11. Method according to one of the preceding claims, characterized in that the material removal device is equipped with a laser (56) and the material removal takes place by means of the laser (56).

12. The method according to claim 10, characterized in that a laser beam (52) of the laser (56) is moved relative to the cutting tool (1, 21) by means of an optical laser beam deflection device (57) and that this movement is superimposed on the movement of the cutting tool (1, 21) generated by the movement device (53).

13. Method according to one of claims 1 to 10, characterized in that the material removal device is equipped with a grinding wheel and the material removal takes place with the grinding wheel.

14. Method according to one of claims 1 to 9, characterized in that the material removal is carried out by means of electrical discharge machining EDM.

15. Method according to one of the preceding claims, characterized in that the cutting insert (3, 4, 5, 23) consists of an ultra-hard material such as polycrystalline diamond (PCD), cubic boron nitride (CBN), chemical vapor deposition (CVD) diamond, single-crystal diamond or ceramic.

16. Method according to one of the preceding claims, characterized in that the 3-dimensional cutting tool surface (17) is determined from given CAD data of the cutting tool (1, 21).

17. Method according to one of the preceding claims, characterized in that the 3-dimensional cutting tool surface (18) is generated by means of a surface scanner (59) which scans the surface of the cutting tool. Method according to one of the preceding claims, characterized in that a grid of partial surfaces (14) is placed over the 3-dimensional cutting tool surface (17, 18), that the orientation relative to the geometric cutting tool rotation axis (6, 26) is determined for each partial surface (14), and that the cutting edge boundary surfaces (11a, 12a, 31a, 32a) are determined from this. Method according to claim 18, characterized in that the partial surfaces (14) are triangles. Method according to claim 18 or 19, characterized in that the orientation of any two adjacent partial surfaces (14) is compared with one another, and that the cutting edge boundary surfaces (11a, 12a, 31a, 32a) are determined from this. Method according to one of the preceding claims, characterized in that the collision-free movement path is determined with the aid of Minkowski addition.Machining device for machining a cutting tool (1, 21) which has a cutting tool body (2, 22) and at least one cutting insert (3, 4, 5, 23) fastened to the cutting tool body (2, 22) and having at least one cutting edge (10, 30), wherein the machining device (50) has a fixing device (51) which receives and fixes the cutting tool (1, 21), a material removal device (56) which removes material from the surface of the cutting tool (1, 21), and a movement device (53), wherein the movement device (53) moves the cutting tool (1, 21) received in the fixing device (51) and the material removal device (56) for targeted material removal relative to. moved towards one another, characterized in that the processing device (50) comprises a control device (58) which is designed to control the fixing device (51), the movement device (53) and the material removal device (56) in such a way that they carry out the method according to one of the preceding claims on the cutting tool (1, 21). Processing device according to claim 22, characterized in that the material removal device is equipped with a laser (56) which removes material from the cutting edge boundary surfaces (11a, 12a, 31a, 32a) by laser processing the cutting edge boundary surfaces (11a, 12a, 31a, 32a). Processing device according to claim 22, characterized in that the material removal device is equipped with at least one grinding wheel which removes material from the cutting edge boundary surfaces by chip removal by grinding.Machining device according to claim 22, characterized in that the material removal device is designed to remove material from the cutting edge boundary surfaces by means of electrical discharge machining (EDM). Machining device according to one of claims 22 to 25, characterized in that it is equipped with a surface scanner (59) which detects the surface of the cutting tool (1, 21) at least in those sections of the cutting tool (1, 21) which comprise the cutting insert (3, 4, 5, 23). Machining device according to one of claims 22 to 26, characterized in that it is equipped with a coordinate measuring device (60) which measures the coordinates of the surface of the cutting insert (3, 4, 5, 23) at specific measuring points (16). Cutting tool relative to a given coordinate system.

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