METHOD FOR REPAIRING A MACHINING TOOL

Description

[0001] The invention relates to a method for repairing a cutting tool according to the preamble of claim 1. Such a method is known from document US 6 189 584 B1.

[0002] Particularly in woodworking, rotary-driven cutting tools are widely used. These comprise a tool body and at least one, usually several, cutting inserts, each separate from the tool body, each with a cutting edge. The tool body is provided with receiving pockets, each holding a cutting insert. Typically, the back of the receiving pocket has a radially protruding elevation, the so-called stud. The rear wall of the receiving pocket and the front surface of the studs together form a continuous support surface against which the rear sides of the individual cutting inserts rest, thereby supporting them against the cutting forces that occur. The cutting inserts only have a limited service life, after which the cutting tool becomes blunt. To repair the cutting tool, the cutting edges are resharpened.This also removes part of the stud. Once the entire stud has been removed, the cutting edges can no longer be resharpened because they no longer protrude radially from the receiving pockets. At this point, the life cycle of the cutting tool has reached its end, and the entire cutting tool must be replaced.

[0003] Even with studless cutting tools, as described in DE 10 2020 109 739 A1, repair of the cutting tool is only possible to a limited extent until the last possible resharpening process. This marks the end of the tool's life cycle.

[0004] US Pat. No. 6,189,584 B1 describes that, for milling heads equipped with carbide inserts held in holders, it is common practice to resharpen the inserts and push the holders radially outward. The inserts are arranged in grooves open at their longitudinal ends, parallel to the rotation axis. After several resharpening processes, the entire assembly is then replaced.

[0005] Similar processes for milling heads are known from US 935,749 A, DE 299 20 262 U1 and US 4,242,927 A, in which the carbide cutting plates are also arranged in grooves open at their longitudinal ends parallel to the axis of rotation.

[0006] US Pat. No. 3,860,051 A discloses a process in which the cutting edges of conical sleeves are resharpened by honing. The sleeves are clamped to a tool body and are replaceable.

[0007] DE 19 22 942 U discloses a circular saw blade in which the chip groove is equipped with carbide.

[0008] The invention is based on the object of providing a method for repairing a cutting tool which enables a long service life of the cutting tool.

[0009] This object is achieved by a method for repairing a cutting tool having the features of claim 1.

[0010] The method according to the invention provides for the cutting edge of the cutting insert to be resharpened at least once. After resharpening at least once, the cutting insert, on which the cutting edge is arranged, protrudes radially relative to the rotation axis beyond the outer contour of the rotating body by a resharpening height. If the resharpening height falls below a threshold height, the cutting insert is removed from the contact surface of the receiving pocket, and a new cutting insert with a new cutting edge is inserted onto the contact surface in the receiving pocket.

[0011] In the case of cutting tools with a stud, such a replacement of a cutting insert was not carried out because after resharpening the stud was worn away and was no longer available to support a newly inserted cutting insert.

[0012] The invention is based on the finding that, in a tool body without studs, as described in the recent prior art according to documents EP 3 354 387 A1 and DE 10 2020 109 739 A1, the replacement of a cutting insert is possible even after the cutting edge of the cutting insert has been resharpened. This makes it possible to use the cutting tool, in particular the tool body of the cutting tool, for a much longer period of time than in the previous prior art. The tool body and in particular the contact surface for the cutting insert are not damaged when resharpening cutting inserts in a cutting tool according to claim 1. This allows a new cutting insert to be inserted onto the undamaged contact surface in the receiving pocket.

[0013] The cutting tool used in the method according to the invention is designed, at least in sections, as a rotating body with respect to the rotational axis. The at least one receiving pocket is machined into the surface of the rotating body and has a contact surface for the cutting insert. The contact surface for the cutting insert lies within the circumferential contour of the rotating body. In particular, the cutting insert protrudes freely and unsupported from the receiving pocket beyond the outer contour of the rotating body.

[0014] Where the tool body is designed as a rotating body, its surface can be easily produced by turning. Milling work is limited to creating the receiving pockets for the cutting inserts. From a geometric perspective, a rotating body is formed, from whose otherwise undisturbed, rotating surface the receiving pockets extend exclusively radially inward, and without any parts or sections of the tool body protruding radially beyond the undisturbed, rotating surface of the tool body. The only parts of the cutting tool that protrude radially outward beyond the undisturbed, rotating surface of the tool body are the cutting edges of the inserted cutting inserts.

[0015] The initial height by which the cutting edge of the cutting insert protrudes from the receiving pocket beyond the outer contour of the rotating body in the radial direction relative to the rotation axis before its very first use can expediently be reduced to the resharpening height in such a way that the size of the contact surface of the receiving pocket is the same before the very first use of the cutting insert and after it has been resharpened at least once. In particular, the initial height can be reduced to the limit height in such a way that the size of the contact surface of the receiving pocket is the same before the very first use of the cutting insert and after it has been resharpened at least once. The initial height can expediently be reduced to the resharpening height, in particular to the limit height, in such a way that the shape of the tool body can remain unchanged compared to the state before the very first use of the cutting insert. In particular, the tool body is not affected by resharpening.

[0016] The resharpening height is smaller than the initial height.

[0017] In particular, the cutting tool is ready for cutting use after resharpening.

[0018] In particular, the cutting edge of the cutting plate is resharpened several times before the new cutting plate is inserted onto the contact surface in the receiving pocket.

[0019] In an advantageous development of the invention, by resharpening the cutting edge, in particular by repeatedly resharpening the cutting edge, it is possible to reduce the cutting insert from its initial height to the resharpened height by at least 0.8 mm. At the same time, the size of the contact surface of the receiving pocket is the same before the very first use of the cutting insert and after the reduction of the cutting insert by resharpening the cutting edge, in particular by repeatedly resharpening the cutting edge.

[0020] Preferably, the difference between the initial height and the limit height is at least 0.8 mm. This allows the cutting insert to be used efficiently.

[0021] In particular, the cutting insert is reduced from the initial height by at least 0.8 mm to the resharpening height before it is removed from the contact surface of the receiving pocket.

[0022] It is preferable to resharpen the cutting edge several times before the cutting insert falls below the limit height.

[0023] This allows the cutting material available through the cutting insert to be used efficiently and economically.

[0024] It may be expedient for the cutting insert to be screwed, clamped, or releasably secured in the receiving pocket in some other way. In a preferred embodiment of the invention, the cutting insert is bonded to the contact surface of the receiving pocket by means of a material connection before the cutting insert is used for the very first time. In particular, the material connection is a soldered connection. This results in a flat attachment of the cutting insert with good holding and support properties. The tool body can be kept very simple in design. The material connection connecting the cutting inserts to the contact surface of the receiving pocket can be easily released if the resharpening height falls below the limit height. The cutting insert can be removed from the receiving pocket without complications.It is advisable to loosen the material bond between the cutting insert and the contact surface of the receiving pocket before the cutting insert is removed from the contact surface of the receiving pocket.

[0025] Preferably, the new insert is bonded to the contact surface of the receiving pocket by means of a material connection when the new insert is inserted into the receiving pocket. In particular, the new insert is bonded to the contact surface of the receiving pocket by means of a material connection by soldering the new insert to the contact surface. This allows for simple and straightforward insertion of the new insert.

[0026] Various materials are considered for the cutting insert. The cutting edge of the cutting insert is made of polycrystalline diamond. This ensures a correspondingly long service life. According to the invention, the new cutting edge of the cutting insert is made of polycrystalline diamond.

[0027] The new cutting insert has a new cutting edge. The new cutting insert protrudes with its new cutting edge on the receiving pocket beyond the outer contour of the rotating body in the radial direction by a new initial height. The new initial height of the new cutting insert is advantageously at least 70% of the initial height of the cutting insert before the very first use of the cutting insert. In particular, the new initial height is at least 90% of the initial height of the cutting insert before the very first use of the cutting insert. Preferably, the new initial height of the new cutting insert corresponds to the initial height of the cutting insert before the very first use of the cutting insert. Advantageously, the new initial height is at least 100% of the initial height of the cutting insert before the very first use of the cutting insert. This makes it possible to repair the cutting tool so that its functionality corresponds to the cutting tool before the very first use of the cutting tool.In particular, the newly inserted cutting insert is supported in the same way in the receiving pocket. In particular, the new cutting insert can be resharpened just as often as the old cutting insert.

[0028] Preferably, the new initial height of the new cutting insert is at most 1.5 mm smaller than the initial height of the cutting insert before the very first use of the cutting insert.

[0029] Advantageously, the contact surface of the receiving pocket for the cutting insert comprises a support surface. In particular, the support surface lies within the circumferential contour of the rotating body. The support surface expediently supports the cutting insert against any cutting forces that may occur. In particular, the support surface is delimited by the circumferential contour of the rotating body. In particular, the contact surface is formed exclusively by the support surface. This enables particularly simple detachment of the cutting insert from the contact surface. The contact surface is therefore particularly easily accessible. In addition, the support surface can be designed to be large. The cutting insert, or the new cutting insert, can be reliably held and supported. Expediently, the support surface extends essentially radially to the axis of rotation.

[0030] In an advantageous development of the invention, the cutting tool has a plurality of receiving pockets and a plurality of cutting inserts. In particular, it is provided that when one of the plurality of cutting inserts is removed from the associated receiving pocket, all of the plurality of cutting inserts are removed from the other associated receiving pockets. In particular, new cutting inserts are then inserted into all of the receiving pockets associated with the plurality of cutting inserts. In other words, a complete replacement of all cutting inserts takes place, in particular as soon as the resharpening height for one of the plurality of cutting inserts falls below the limit height.

[0031] The surface of the rotating body can be brightly turned and accordingly smooth. In an advantageous development, a surface structure is formed on the surface of the rotating body to reduce noise emissions. Such a surface structure can expediently be formed in particular on a circumferential surface and / or on at least one end face of the rotating body. The term "surface structure" refers to structures that are based on the circumferential surface of the rotating body and that are produced in particular in a circumferentially rotating process. This can be knurling, for example. The surface structure is expediently formed as a groove structure running in the circumferential direction of the rotating body and can therefore be easily produced by turning.The surface structure does not have to completely cover the surface of the rotational body, but advantageously extends right up to the edge of the receiving pocket, where it is intersected by at least one wall of the receiving pocket.

[0032] Embodiments of the invention are described in more detail below with reference to the drawings. They show: Fig. 1 a perspective view of a cutting tool according to the invention with a cylindrical basic shape, the tool body of which is designed on the peripheral surface and the end faces as a rotary body with a groove structure and incorporated receiving pockets for the cutting inserts, Fig. 2 an enlarged detail of the tool body from Fig. 1 with details on the design of the receiving pockets, Fig. 3 the detail from Fig. 2 , where cutting plates are inserted into the receiving pockets of the tool body, Fig. 4 a detailed view of the cutting tool according to Fig. 1in the area of ​​the end face of the cutting tool with details of a radially and axially open receiving pocket, Fig. 5 a perspective view of a further embodiment of a cutting tool according to the invention with a cylindrical basic shape, the tool body of which is designed on the peripheral surface and the end faces as a rotation body with a smooth surface and incorporated receiving pockets for the cutting plates, Fig. 6 an enlarged detail from Fig. 5 with details on the design of the receiving pockets, Fig. 7 the detail from Fig. 6, wherein cutting plates are inserted into the receiving pockets of the tool body, Fig. 8 a perspective view of a cutting tool designed as an end mill with a cylindrical basic shape, on whose tool body receiving pockets for cutting plates are provided on both the peripheral surface and the end face, Fig. 9 a detailed view of the cutting tool according to Fig. 1 before the very first use of the cutting inserts, Fig. 10 the view of the cutting tool according to Fig. 9 with a cutting plate whose resharpening height is below the limit height, Fig. 11 the view after the Fig. 9 and 10 of the cutting tool with a new cutting plate with a new initial height inserted into the receiving pocket, Fig. 12Detailed view of a cutting tool from the prior art, the cutting plate of which is supported by a stud and Fig. 13The view from Fig. 12, whereby the cutting plate of the cutting tool was resharpened and part of the stud was also removed.

[0033] The Fig. 1 to 11 show a total of three different embodiments of a cutting tool on which the method according to the invention is carried out. The following description generally applies to all three embodiments. Therefore, the same reference numerals are used for all embodiments. Any deviations between the embodiments will be explicitly noted.

[0034] The Fig. 1 to 4 show a cutting tool 1 with a substantially cylindrical tool body 2, which has a groove-shaped surface structure 6 on its peripheral side 7 and on its front side 8.

[0035] The cutting tool 1 according to the Fig. 5 to 7 differs from the cutting tool 1 according to the Fig. 1 to 4in that it has no surface structure, but has a smooth surface on both its peripheral side 7 and its front side 8.

[0036] Fig. 8 shows a cutting tool 1 designed as an end mill. The surface of the end mill is smooth on both its peripheral side 7 and its front side 8.

[0037] The Fig. 9 to 11 show the individual process steps as examples for all embodiments carried out on the cutting tool 1 according to the Fig. 1 to 4 .

[0038] The Figs. 12 and 13 show a cutting tool 30 from the prior art, the tool body 31 of which has studs 32 as support surfaces for cutting inserts 33. Fig. 12 shows the cutting tool 30 before resharpening the cutting plate 33 and Fig. 13shows it after resharpening the cutting insert 33. A comparison of the two figures shows that the stud 32 is at least partially removed during resharpening. A newly inserted cutting insert with the original height of the cutting insert 33 would no longer be adequately supported by the removed stud 32 and would not be able to absorb the cutting forces occurring during operation without sustaining damage or becoming detached from the tool body 31. Replacing the cutting inserts 33 is not provided for in the prior art.

[0039] The common properties of the embodiments according to the invention according to the Figures 1 to 11are described below: The cutting tool 1 according to the invention is used for cutting wood or similar materials. Similar materials here means materials with physical and technological properties similar to those of wood, such as cork, bone, plastic, light metal alloys, wood-based materials such as chipboard, wood fiberboard, plywood, etc., and for which the process for processing and removing chips or particles is similar. The cutting tool 1 comprises a tool base body 2 and at least one, here several cutting inserts 10. The tool base body 2 is made in one piece from steel, but can also be made of another suitable material. The cutting inserts 10 are formed separately from the tool base body 2 as individual parts and are fastened to the tool base body 2. The cutting tool 1 and its tool base body 2 have a common axis of rotation 3.During operation, the cutting tool 1 is driven to rotate about this axis of rotation 3 in a direction of rotation 4, whereby outer cutting edges 11 of the cutting plates 10 are brought into engagement with a workpiece (not shown) and chips are removed.

[0040] The tool body has a surface 5. In the exemplary embodiments, the tool body 2 is essentially cylindrical with a circumferential surface 7 and two axially opposite end faces 8. However, within the scope of the invention, a conical shape or another shape may also be expedient. In any case, the cutting edges 11 protrude radially and / or axially beyond the outer contour of the tool body 2 so that sufficient free space remains between the workpiece and the surface 5 of the tool body 2 during the machining process. In the exemplary embodiments, the surface 5 is formed by the circumferential surface 7 and the end faces 8.

[0041] The tool base body 2 is designed, in a geometric sense, at least in sections as a rotary body 20 with respect to the rotation axis 3. In other words, this means that in this region, the surface of the tool base body 2 is formed by a 360° rotation of a contour line around the rotation axis 3. According to the invention, recesses can be machined into the surface of the rotary body 20, for example to form receiving pockets 13 for the cutting inserts 10. However, no elevations of the tool base body 2 protrude above the undisturbed surface of the rotary body 20. In the exemplary embodiments, the tool base body 2 is designed entirely as a rotary body 20, 20', both in the region of its peripheral surface 7 and in the region of its two end faces 8.Within the scope of the invention, however, it may also be expedient to design only one of the two end faces 8, only a part of the circumferential surface 7 or, in another suitable manner, only a section of the tool base body as a rotational body 20.

[0042] Receiving pockets 13 for the cutting inserts 10 are machined into the surface of the rotating body 20, 20'. A cutting insert 10 is secured in each receiving pocket 13 such that its cutting edge 11 protrudes from the receiving pocket 13 beyond the outer contour of the rotating body 20. In the exemplary embodiments, several receiving pockets 13 are provided. Accordingly, several cutting inserts 10 are also provided.

[0043] As shown in the figures, a radial direction 50 is defined with respect to the rotational axis 3. The radial direction 50 points radially away from the rotational axis 3, in particular in all directions perpendicular to the rotational axis 3. The radial direction 50 runs perpendicular to the rotational direction 4. The cutting insert 10 protrudes beyond the outer contour of the rotating body 20 in the radial direction 50. In particular, the cutting edge 11 of the cutting insert 10 is arranged outside the outer contour of the rotating body 20 in the radial direction 50.

[0044] The receiving pocket 13 is arranged within the outer contour of the rotating body 20 with respect to the radial direction 50.

[0045] The cutting edges 11 of the cutting inserts 10 are preferably made of polycrystalline diamond (PCD). For this purpose, a PCD layer can be sintered onto a hard metal substrate. It is also conceivable that these are pure PCD cutting inserts, particularly with a thickness between 0.6 mm and 2.0 mm.

[0046] The Fig. 2 and 3 show in enlarged detail view the tool body 2 after Fig. 1 in the area of ​​its peripheral surface 7. In an analogous manner, the Figs. 6 and 7 in an enlarged detailed view of the tool body 2 after Fig. 5 in the area of ​​its peripheral surface 7. Deviating from the Fig. 1 and 3 or the Fig. 5 and 7 For better clarity, Fig. 2 or Fig. 6 the cutting plates 10 are not shown. In any case, in particular in Fig. 2 or Fig. 6 It can be seen that receiving pockets 13 are formed there, which extend radially inward from the undisturbed surface of the rotating body 20. According to the invention, the receiving pockets 13 are delimited by a circumferential surface edge 9, at which the surface of the rotating body 20 is intersected by the walls of the receiving pocket 13.

[0047] The receiving pocket 13 comprises a contact surface 16. The contact surface 16 serves to support the cutting insert 10. The contact surface 16 comprises a support surface 22. The support surface 22 serves to support the cutting insert 10 against cutting forces occurring during operation of the cutting tool 1. The support surface 22 runs transversely to the direction of rotation 4. The support surface 22 lies radially within the circumferential contour of the rotating body 20. In the exemplary embodiments, the support surface 22 forms the entire contact surface 16. The contact surface 16 is formed exclusively by the support surface 22. In the exemplary embodiments, the contact surface 16 is formed in the rear region of the receiving pocket 13 with respect to the direction of rotation 4. However, it can also be provided that the contact surface extends at least partially in a surface transverse to the radial direction. According to the illustration according to Fig. 3 , or Fig. 7 the cutting plate 10 rests on the contact surface 16.

[0048] According to the invention, the cutting inserts 10 are attached to the contact surfaces 16. According to the invention, the cutting insert 10 is attached to the contact surface 16 by means of a material bond. In particular, the cutting insert 10 is soldered to the contact surface 16. Within the scope of the invention, other material bonds between the cutting inserts 10 and their contact surfaces 16, such as gluing or the like, are also possible.

[0049] In particular from the representations according to Fig. 2 and Fig. 6 and the geometric definition of the rotating body 20, it follows that there are no support studs behind the cutting plates 10 in the cutting tools used for the method according to the invention. The studs 21 used in the prior art are in Fig. 13shown. In the cutting tools 1 used according to the invention, the contact surface 16 lies radially within the circumferential contour of the rotating body. In the exemplary embodiments, the contact surface 16 is delimited by the rotating body. In other words: if one now considers two points on the surface edge 9, namely any point on the leading section of the surface edge 9 and a corresponding second point which, in the direction of rotation 4, lies exactly behind the first point on the surface edge 9 in the region of the contact surface 16, both points lie in the same axial and radial position. However, other designs can also be provided in which this is not the case, but the surface edge 9 at least does not protrude from the rotating body. For example, at least part of the surface edge 9 or even the entirety can be arranged at a distance from the rotating body within the rotating body.

[0050] Furthermore, in the Fig. 2, 3 (not in the Fig. 6, 7) it can also be seen that a surface structure 6 for reducing sound emissions is formed on the surface of the rotating body 20. The surface structure can be knurling or the like and, in the preferred exemplary embodiment shown, is formed as a groove structure running in the circumferential direction of the rotating body 20 and produced by turning. It can be expedient to provide only part of the rotating body 20 with a surface structure. Here, however, the rotating body 20 has a completely structured surface. In particular, the surface structure extends right up to the edge or surface edges 9 of the receiving pockets 13, so that the groove structure is interrupted by the receiving pockets 13. In other words, the walls of the receiving pockets 13 intersect the structured surface or the groove structure, as a result of which the surface edges 9 are jagged orwavy and act as aerodynamic turbulators to reduce noise. However, it may also be expedient to provide the rotating body with a smooth surface, particularly in the area of ​​the receiving pockets 13.

[0051] Fig. 4 shows a detailed view of the cutting tool after the Fig. 1 to 3in the region of one of its end faces 8. Accordingly, it can be seen that the receiving pockets 13 can be open not only in the radial direction, but also in the axial direction. In any case, the end face 8 designed as a rotating body 20' is interrupted by axially inward-extending receiving pockets 13, forming surface edges 9. Since the end face 8 designed as a rotating body 20' is also provided with a surface structure 6, a similarly wavy or jagged course of the surface edges 9 results. The relationships mentioned are described here as an example for a cylindrical tool base body 2 with a circumferential surface 7 designed as a rotating body 20 and with end faces 8 designed as rotating bodies 20', but also apply analogously to other basic geometric shapes of the tool base body 2.

[0052] Based on the Fig. 9 to 11The method according to the invention for repairing the cutting tool 1 can be described by way of example for all versions of the cutting tool 1. Fig. 9 shows the cutting tool 1 before the very first use of the cutting insert 10. The cutting insert 10 is completely unused. The cutting insert 10 is, in particular, brand new. In particular, the cutting insert 10 is in Fig. 9 not yet sharpened. This applies in Fig. 9 for all cutting inserts 10. In this context, resharpening does not refer to a process step in the manufacture of the cutting tool in which the cutting inserts 10 are initially and once brought to the same height or level with respect to the radial direction 50. Resharpening can only take place after this initial height adjustment, in particular after use of the cutting tool 1.

[0053] The cutting insert 10 is secured in the receiving pocket 13 and, prior to its very first use, protrudes from the receiving pocket 13 beyond the outer contour of the rotating body 20 in the radial direction 50 by an initial height ha. The very first use refers to the very first operation of the cutting tool 1 during which the cutting edge 11 of the cutting insert 10 machines a workpiece. The very first use refers to the time immediately before the very first use. Thus, at this point in time, the height of the cutting inserts 10 has already been adjusted to a uniform level.

[0054] The initial height ha is measured in the radial direction 50 from the outer contour of the rotating body 20 to the point on the cutting insert 10 that is furthest away from the rotation axis 3 in the radial direction 50. The initial height ha is measured in the radial direction 50 perpendicular to the outer contour of the rotating body 20. The cutting edge 11 is a component of the cutting insert 10. The cutting edge 11 is also referred to as the cutting edge. The cutting edge 11 lies completely outside the outer contour of the rotating body 20 in the radial direction 50.

[0055] The cutting edge 11 of the cutting plate 10 made of Fig. 9 is resharpened at least once.

[0056] According to the invention, resharpening is carried out by erosion, in particular by spark erosion. EDM (abbreviated to electrical discharge machining, also known as spark erosion machining, spark erosive removal (DIN 8580), or electroerosive machining) is a thermal, abrasive process for conductive materials that relies on electrical discharge processes (sparks) between the electrode as the tool and the conductive workpiece, in this case the cutting insert 10, in particular the cutting edge 11.

[0057] As in Fig. 10As shown, the cutting insert 10, which is still fastened in the receiving pocket 13, protrudes in the radial direction 50 beyond the outer contour of the rotating body 20 by a resharpening height hn after it has been resharpened at least once. The resharpening height hn of the cutting insert 10 after resharpening is measured in the radial direction 50 from the outer contour of the rotating body 20 to the point on the cutting insert 10 furthest away from the rotation axis 3 in the radial direction 50. The resharpening height hn is measured in the radial direction 50 perpendicular to the outer contour of the rotating body 20.

[0058] The resharpening height hn is smaller than the initial height ha. If the resharpening height hn of the cutting insert 10, after it has been resharpened, falls below a limit height hg, the cutting insert 10 is removed from the contact surface 16 of the receiving pocket 13. The limit height hg is measured in the radial direction 50 perpendicular to the outer contour of the rotating body 20. The limit height hg of the cutting insert 10 is measured in the radial direction 50 from the outer contour of the rotating body 20. In Fig. 10 the resharpening height hn falls below the limit height hg, so that the cutting plate 10 is removed from the contact surface 16.

[0059] After the cutting insert 10 has been removed from the contact surface 16 of the receiving pocket 13, a new cutting insert 110 is inserted onto the contact surface 16 in the receiving pocket 13 of the tool base body 2 of the cutting tool 1. Fig. 11 shows the unchanged tool body 2 with a new cutting insert 110.

[0060] The cutting tool 1, in particular the tool body 2, can continue to be used even though at least one of the cutting inserts 10 has reached the end of its life cycle. Replacing the entire cutting tool 1, and in particular the tool body 2, is not necessary.

[0061] The new cutting plate 110 has a new cutting edge 111. The new cutting edge 111 is arranged in the radial direction 50 outside the outer contour of the rotating body 20.

[0062] The initial height ha can be reduced to the resharpening height hn such that the size of the contact surface 16 of the receiving pocket 13 is the same before the very first use of the cutting insert 10 and after the cutting insert 10 has been resharpened at least once. The initial height ha can be reduced to the limit height hg such that the size of the contact surface 16 of the receiving pocket 13 is the same before the very first use of the cutting insert 10 and after the cutting insert 10 has been resharpened at least once. As a comparison of the Fig. 9 and 10 shows, the contact surface 16 is unaffected by the resharpening of the cutting plate 10. The size of the Fig. 2 and 6 The support surface 22 shown is in front of ( Fig. 9 ) and after ( Fig. 10 ) the cutting plate 10 was resharpened the same size.

[0063] The initial height ha can be reduced to the resharpening height hn such that the shape of the tool body 2 remains unchanged compared to the state before the very first use of the cutting insert 10. The initial height ha can be reduced to the limit height hg such that the shape of the tool body 2 remains unchanged compared to the state before the very first use of the cutting insert 10. This is shown by a comparison of the Fig. 9 and 10 .

[0064] By resharpening the cutting edge 11, in particular by multiple resharpening of the cutting edge 11, a reduction of the cutting plate 10 from the Fig. 9 The initial height ha shown can be reduced to the resharpening height hn by at least 0.8 mm. Even if the cutting insert 10 is reduced from the initial height ha to the resharpening height hn by 0.8 mm, the size of the contact surface 16 of the receiving pocket 13 remains the same as before the very first use of the cutting insert 10.

[0065] The difference between the initial height ha and the limit height hg is at least 0.8 mm.

[0066] In the exemplary embodiments, the cutting edge 11 is resharpened several times before the cutting plate 10 falls below the limit height hg.

[0067] Before the very first use of the cutting plate 10, the cutting plate 10 is connected to the contact surface 16 of the receiving pocket 13 by means of a material bond, in the exemplary embodiment by means of a soldered connection.

[0068] The material bond between the cutting insert 10 and the contact surface 16 of the receiving pocket 13 is released before the cutting insert 10 is removed from the contact surface 16 of the receiving pocket 13. In the exemplary embodiment, the solder joint can be heated for this purpose. This can be achieved, for example, by means of an electromagnetic induction effect by inducing current into the cutting insert 10 or the tool body 2. This process is also referred to as inductive soldering.

[0069] The new cutting insert 110 is connected to the contact surface 16 of the receiving pocket 13 by means of a material bond. In the exemplary embodiments, the new cutting insert 110 is brazed to the contact surface 16 when the new cutting insert 110 is inserted onto the contact surface 16 in the receiving pocket 13. Here, too, the new cutting insert 10 or the tool body 2 is heated by inducing current into the cutting insert 10 or the tool body 2. The brazed connection between the new cutting insert 110 and the contact surface 16 is established by inductive brazing.

[0070] The new cutting insert 110, which is then secured in the receiving pocket 13, protrudes from the receiving pocket 13 beyond the outer contour of the rotating body 20 in the radial direction 50 by a new initial height han. This is exemplary for all embodiments in Fig. 11The new initial height han is measured in the radial direction 50 from the outer contour of the rotating body 20 to the point of the new cutting insert 110 that is furthest away from the rotation axis 3 in the radial direction 50. The new initial height han is measured in the radial direction 50 perpendicular to the outer contour of the rotating body 20.

[0071] The new cutting insert 110 has a new cutting edge 111. The new cutting edge 111 is a component of the new cutting insert 110. The new cutting edge 111 is also referred to as the new cutting edge. The new cutting edge 11 is located completely outside the outer contour of the rotating body 20 in the radial direction 50.

[0072] The Fig. 11 The new initial height han of the new cutting plate 110 shown is at least 70% of the Fig. 9illustrated initial height ha of the cutting plate 10 before the very first use of the cutting plate 10. The new initial height han of the new cutting plate 110 is in particular at least 90% of the initial height ha of the cutting plate 10 before the very first use of the cutting plate 10. In the exemplary embodiments, the new initial height han of the new cutting plate 110 is at least 100% of the initial height ha of the cutting plate 10 before the very first use of the cutting plate 10. In the exemplary embodiments, the new initial height han of the new cutting plate 110 corresponds approximately to the initial height ha of the cutting plate 10 before the very first use of the cutting plate 10. Preferably, the new initial height han of the new cutting plate 110 is from 90% to 110% of the initial height ha of the cutting plate 10 before the very first use of the cutting plate 10.In the exemplary embodiments, the new cutting insert 110, which is inserted into the receiving pocket 16, is structurally identical to the cutting insert 10 before its very first use. The new cutting insert 110, in particular the cutting tool 1, is ready for use with the new initial height han.

[0073] The new initial height han of the new cutting plate 110 is at most 1.5 mm, in the exemplary embodiments at most 1.0 mm smaller than the initial height ha of the cutting plate 10 before the very first use of the cutting plate 10.

[0074] The cutting edge 11 of the cutting insert 10 is made of polycrystalline diamond. The new cutting edge 111 of the new cutting insert 110 is made of polycrystalline diamond.

[0075] In the exemplary embodiments, when one of the plurality of cutting inserts 10 is removed from the associated receiving pocket 13, all of the plurality of cutting inserts 10 are removed from the respectively associated receiving pockets 13. New cutting inserts 110 are then inserted into all of the respectively associated receiving pockets 13.

[0076] After replacing a single insert or all inserts, it may be necessary to bring the newly installed inserts to the same protrusion height. This can be done by resharpening, particularly by erosion. The protrusion height then achieved is the height referred to above as the new initial height and meets all the criteria described in this context, particularly with regard to the ratio of new initial height to initial height.

[0077] In the case of the cutting tool 1 designed as an end mill according to Fig. 8A receiving pocket is arranged on the end face 8 of the tool body 2. The associated cutting insert protrudes beyond the outer contour of the rotating body 20 in the direction of the rotation axis 3. With the exception that this cutting insert protrudes in the axial and not the radial direction, all of the above statements also apply to this cutting insert. The described method for repairing the cutting tool 1 can also be applied analogously to this cutting insert. Quantities measured in the radial direction 50 must be measured analogously in the axial direction.

Claims

1. Method for repairing a cutting tool, wherein the cutting tool (1) comprises: - a tool main body (2) and - at least one cutting insert (10) which is separate from the tool main body (2) and which has a cutting edge (11), wherein the cutting edge (11) of the cutting insert (10) is formed from polycrystalline diamond, wherein the tool main body (2) has an axis of rotation (3) and, during operation of the cutting tool (1), rotates in a direction of rotation (4) about the axis of rotation (3), and wherein the tool main body (2) is provided with at least one receiving pocket (13) for the cutting insert (10), wherein, in relation to the axis of rotation (3), the tool main body (2) is at least sectionally in the form of a body of rotation (20), wherein the at least one receiving pocket (13) is formed in the surface of the body of rotation (20) and has an abutment surface (16), situated within the circumferential contour of the body of rotation (20), for the cutting insert (10), wherein the at least one receiving pocket (13) is delimited by a peripheral surface edge (9) at which the surface of the body of rotation (20) is intersected by the walls of the receiving pocket (13), wherein the cutting insert (10) abuts against the abutment surface (16) of the receiving pocket (13), wherein the cutting insert (10) is fastened to the abutment surface (16) by means of material bonding, and wherein the cutting edge (11) of the cutting insert (10), prior to the very first use thereof, protrudes, in a radial direction (50) in relation to the axis of rotation (3), by an initial height (ha) out of the receiving pocket (13) beyond the outer contour of the body of rotation (20), characterized in that - the cutting edge (11) of the cutting insert (10) is re-sharpened at least once by means of erosion, in that the cutting edge (11) of the cutting insert (10), after re-sharpening has been carried out at least once, protrudes, in the radial direction (50) in relation to the axis of rotation (3), by a re-sharpening height (hn) out of the receiving pocket (13) beyond the outer contour of the body of rotation (20), wherein the re-sharpening height (hn) is smaller than the initial height (ha), - in that the cutting insert (10) is removed from the abutment surface (16) of the receiving pocket (13) if the re-sharpening height (hn) falls below a limit height (hg), and - in that a new cutting insert (110) with a new cutting edge (111) is then inserted into the receiving pocket (13) onto the abutment surface (16).

2. Method according to Claim 1, characterized in that the initial height (ha) is reducible to the re-sharpening height (hn), in particular to the limit height (hg), in such a way that the size of the abutment surface (16) of the receiving pocket (13) is the same prior to the very first use of the cutting insert (10) as it is after re-sharpening has been carried out at least once.

3. Method according to Claim 2, characterized in that the initial height (ha) is reducible to the re-sharpening height (hn), in particular to the limit height (hg), in such a way that the shape of the tool main body (2) can be unchanged in comparison with the state prior to the very first use of the cutting insert (10).

4. Method according to Claim 2 or 3, characterized in that, by re-sharpening the cutting edge (11), in particular by re-sharpening the cutting edge (11) multiple times, the cutting insert (10) can be reduced from the initial height (ha) to the re-sharpening height (hn) by at least 0.8 mm and, at the same time, the size of the abutment surface (16) of the receiving pocket (13) is the same prior to the very first use of the cutting insert (10) as it is after the reduction of the cutting insert (10).

5. Method according to one of Claims 2 to 4, characterized in that the difference between the initial height (ha) and the limit height (hg) is at least 0.8 mm.

6. Method according to one of Claims 1 to 5, characterized in that the cutting edge (11) is re-sharpened multiple times before the cutting insert (10) falls below the limit height (hg).

7. Method according to one of Claims 1 to 6, characterized in that, prior to the very first use of the cutting insert (10), the cutting insert (10) is connected to the abutment surface (16) of the receiving pocket (13) by means of material bonding, in particular by means of a soldered connection.

8. Method according to Claim 7, characterized in that the material bond of the cutting insert (10) to the abutment surface (16) of the receiving pocket (13) is released prior to the cutting insert (10) being removed from the abutment surface (16) of the receiving pocket (13).

9. Method according to one of Claims 1 to 8, characterized in that the new cutting insert (110) is connected to the abutment surface (16) of the receiving pocket (13) by means of material bonding, in particular in that the new cutting insert (110) is soldered to the abutment surface (16) when the new cutting insert (110) is inserted into the receiving pocket (13) onto the abutment surface (16).

10. Method according to one of Claims 1 to 9, characterized in that the new cutting insert (110) has a new cutting edge (111), in that new cutting edge (111) of the new cutting insert (110) protrudes, in the radial direction (50), by a new initial height (han) out of the receiving pocket (13) beyond the outer contour of the body of rotation (20).

11. Method according to Claim 10, characterized in that the new initial height (han) of the new cutting insert (110) is at least 70%, in particular at least 90%, preferably at least 100% of the initial height (ha) of the cutting insert (10) prior to the very first use of the cutting insert (10).

12. Method according to Claim 10 or 11, characterized in that the new initial height (han) of the new cutting insert (110) is at most 1.5 mm smaller than the initial height (ha) of the cutting insert (10) prior to the very first use of the cutting insert (10).

13. Method according to one of Claims 1 to 12, characterized in that the abutment surface (16) of the receiving pocket (13) for the cutting insert (10) comprises a supporting surface (22), in that the supporting surface (22) is situated within the circumferential contour of the body of rotation (20), and in that the supporting surface (22) supports the cutting insert (10) against cutting forces that occur.

14. Method according to Claim 13, characterized in that the abutment surface (16) is formed exclusively by the supporting surface (22).

15. Method according to one of Claims 1 to 14, characterized in that the cutting tool (1) has multiple receiving pockets (13) and multiple cutting inserts (10), in that the removal of one of the multiple cutting inserts (10) from the assigned receiving pocket (13) results in the removal of all of the multiple cutting inserts (10) from the respectively assigned receiving pockets (13), and in that new cutting inserts (110) are then inserted into all of the respectively assigned receiving pockets (13).