Reusable guide plate and drilling tool having a replaceable guide plate

Abstract

The invention relates to a spiral guide plate and a corresponding drilling tool, wherein the spiral guide plate has very small dimensions but has a plurality of guide surfaces despite the small dimensions. Therefore, the spiral guide plate according to the invention can be used for a long time even with drilling tools having small drilling diameters.

Description

Technical Field

[0001] The present invention relates to a drilling tool comprising at least one replaceable guide plate (hereinafter also referred to as "indexable guide plate") for machining on drilling machines, lathes, machining centers and other machine tools, and the invention also relates to associated guide plates. Background Art

[0002] Drilling tools with indexable guide plates are available in a variety of designs. By way of example, but not in an exhaustive manner, BTA drill bits, ejector drill bits, single-edge deep drilling tools and double-edge deep drilling tools are indicated.

[0003] The present invention can be used for all types of drilling tools. In the following, for the sake of language simplicity, only drilling tools are mentioned; this means all types of drilling tools.

[0004] The drilling tool generally comprises a clamping end, a shank and a drill bit. The clamping end, the shank and the drill bit may be made in one piece. The clamping end and / or the drill bit may also be brazed, threaded or otherwise connected to the shaft. In this way, the drilling tool is composed of a plurality of interconnected parts.

[0005] Deep drilling tools are characterized in that they can be used to produce deep holes with a length-to-diameter ratio L / D ≥ 10. A length-to-diameter ratio of L / D>100 can be achieved. These deep drilling tools are usually single-edged tools. Therefore, asymmetric lateral forces act on the drilling tool during machining. This requires guiding the drilling tool via a drill bushing or a guide hole during point drilling, but at the same time allows the drilling tool to guide itself in the previously produced hole with high precision via guide surfaces in the drill head area at the front end of the drilling tool. This allows large drilling depths with small offsets, that is, small deviations of the center axis of the hole from the linear nominal path. In addition, due to the acting lateral forces, the guide surfaces smooth the produced hole walls by flattening small ridges and / or grooves of the hole.

[0006] The invention also relates to the geometric design of an indexable guide plate and a plate seat in a drilling tool for the indexable guide plate, so as to achieve a form fit and an easily detachable connection between the indexable guide plate and the drilling tool.

[0007] Various terms of geometry are used to describe the connection between the indexable guide plate and the drilling tool according to the invention and are briefly defined below. These definitions correspond to the usual mathematical definitions, such as those given in the literature by W. Gellert, Dr. H. Küstner, Dr. M. Hellwich and H. Definitions found in the edited "Groβes Handbuch der Mathematik," and on "Wikipedia."

[0008] Parallel Planes: Two planes are parallel if they are the same distance apart from each other at every point. Hence, planes that are not spaced apart are not parallel planes. Thus, the adjective “parallel” implies the distance between the planes.

[0009] Radial symmetry: A point can be rotated by an angle around the point S The overlapping figures are called rotational symmetry. is equal to 180°, then this is called central symmetry. In the indexable guide plate according to the present invention, the angle Equal to or less than 120°. Point S is the center point; in the indexable guide plate according to the present invention, point S is located on the longitudinal axis of the fastening hole.

[0010] WO 2012 172537 A1, WO 2014 104432 A1 and WO 2014 104431 A1 disclose indexable guide plates and drilling tools having detachably fastened indexable guide plates.

[0011] WO 2014 104431A1 describes an indexable guide plate with a cubic outer contour. In this indexable guide plate, the support surface and the guide surface are arranged orthogonally to each other. Due to this geometry, the indexable guide plate can only be used for drilling tools with relatively large drilling diameters.

[0012] WO 2012 172537 A1 and WO 2014 104432 A1 describe relatively fragile indexable guide plates which have only two guide surfaces on one side. In these arrangements, the transmission of forces between the drill and the indexable guide plate is limited due to the fragile design. If the guide surfaces are worn, the indexable guide plate must be turned 180°. If both guide surfaces on one side are worn, the indexable guide plate can be rotated 180° about its longitudinal axis. Summary of the invention

[0013] The problem addressed by the present invention is to provide an indexable guide plate and a drilling tool comprising an indexable guide plate, which overcome the disadvantages of the prior art. In particular, the indexable guide plate should be fastened in the drilling tool with high repeatability; it should be possible to reliably introduce large guiding forces from the indexable guide plate into the drilling tool. Finally, the indexable guide plate should also be able to be used with drilling tools having small drilling diameters. The "turning over" and replacement of the indexable guide plate should also be possible in a simple and reliable manner under large-scale industrial production conditions.

[0014] According to the invention, this problem is solved by an indexable guide plate for use in a drilling tool, which has a support surface, multiple guide surfaces and a central fastening hole, the indexable guide plate being rotationally symmetrical relative to the longitudinal axis of the fastening hole and the support surface being flat.

[0015] An embodiment of the indexable guide plate according to the present invention has two side surfaces, namely a "lower side" designed as a flat support surface and an "upper side" opposite to the "lower side", and a plurality of guide surfaces are arranged on the "upper side".

[0016] The guide surfaces (usually three or four) occupy the entire or almost the entire upper side of the indexable guide plate. They can be separated from each other by narrow, radially extending recesses. These radially extending recesses are used to separate the guide surfaces from each other similar to undercuts. This facilitates the grinding of the curved guide surfaces.

[0017] Since the guide surface occupies (almost) the entire upper side of the indexable guide plate, the indexable guide plate can be relatively compact. Therefore, they are very strong and extremely resilient and can also be used with drilling tools with smaller drilling diameters. During drilling, the normal forces acting on the relevant working guide surface are directly transmitted to the supporting surface of the indexable guide plate. This in turn is placed in the flat recess of the drilling tool, so that a very direct and therefore very resilient transmission of the normal forces between the working guide surface and the drilling tool occurs. As a result, the drilling tool is very well guided in the hole. This leads to very good geometrical properties of the hole and a very good service life of one or more cutting edges of the drilling tool.

[0018] In an alternative embodiment of the indexable guide plate, the indexable guide plate has two side surfaces and a central fastening hole, wherein a support surface and a plurality of guide surfaces are formed on each side surface, the indexable guide plate is rotationally symmetrical relative to the longitudinal axis of the fastening hole, the guide surfaces on one side surface of the indexable guide plate are separated from each other only by a radially extending recess, and the base of the recess is designed as a flat support surface.

[0019] Since both side surfaces are identical in this exemplary embodiment, a distinction between the upper side and the lower side is possible only via the installation position or the function of the indexable guide plate in the drilling tool.

[0020] Because the base of the depression is designed as a flat support surface, multiple guide surfaces and support surfaces can be formed on the various sides of the indexable guide plate. While the guide surface on the opposite "upper side" guides the drill in the hole, the flat support surface on the "lower side" of the indexable guide plate is active. When all guide surfaces on one side of the indexable guide plate are worn, the indexable guide plate is rotated so that the "upper side" and the "lower side" switch their positions. As a result, the number of guide surfaces and thus the service life of the indexable guide plate can be doubled!

[0021] The guide surfaces and the recesses on the upper side and the guide surfaces and the recesses on the lower side are offset from one another; in the case of three guide surfaces on each side, the offset is equal to 60°. In the case of four guide surfaces on each side, the offset is equal to 45°.

[0022] It has proven to be advantageous if the depression between the guide surfaces is T-shaped at its radially outer ends. The normal forces acting on the relevant working guide surfaces can then be transmitted even more effectively to the drill tool via the optimized support surface on the underside and the load capacity of the indexable guide plate can be further increased with the same geometric dimensions.

[0023] Both embodiments of the indexable guide plate according to the invention require very little space due to their planar structure and the efficient use of the upper side, so that the indexable guide plate according to the invention can be used for drills with relatively small drilling diameters (eg 15 mm).

[0024] In a preferred embodiment, the indexable guide plate according to the invention has a hexagonal or octagonal outer contour. Figure 1 In a first embodiment, an indexable guide plate with three or four guide surfaces can be implemented on one side. In an embodiment according to claim 2, six or eight guide surfaces can be implemented on the indexable guide plate.

[0025] In order for the relevant working guide surface to optimally transmit the normal forces to the hole wall, the longitudinal axis of the recess and the radius beam pointing from the center point to the corner of the outer contour enclose an angle α different from 0°. In the case of a hexagonal outer contour, this angle is usually equal to 60°. In the case of an octagonal outer contour, the angle α is equal to 45°.

[0026] This means that there is no contact between the hole wall and the indexable guide plate in the area of ​​the depression between the guide surfaces, but only in the area of ​​the "working" guide surfaces. This ensures an optimal transmission of forces between the hole and the guide surfaces. This has a positive effect on the quality of the hole and the service life of the drill.

[0027] The guide surface according to the invention is usually curved. The guide surface is preferably designed as a cylindrical surface, wherein the diameter of the cylindrical surface is slightly smaller than the diameter of the hole produced by the drilling tool and the indexable guide plate. In other words: the longitudinal axis of the cylindrical surface of the indexable guide plate and the longitudinal axis of the hole to be machined are not coaxial, but slightly spaced apart from each other. The distance between the longitudinal axes can be, for example, one (1) millimeter, but can also be several millimeters.

[0028] In a development of the drilling tool according to the invention, the support surface for the indexable guide plate and the axis of the drilling tool enclose an angle of from 3° to 15°. The lower limit of this angle is 0°. In other words: the normal vector of the support surface and the axis of the drilling tool enclose an angle of 75° to 87°. The angle is dimensioned so that only one guide surface of the indexable guide plate is in contact with the hole in the workpiece. This guide surface is then "active"; the other guide surfaces are inactive. The inclination of the support surface is dimensioned so that the longitudinal axis of the cylindrical active guide surface of the indexable guide plate and the longitudinal axis of the drilling tool, as described above, enclose an angle β greater than or equal to 0°.

[0029] Due to the rotationally symmetrical design of the indexable guide plate according to the present invention, by flipping the indexable guide plate by an angle of 120° or 90° Worn guide surfaces can be decommissioned and replaced with new, unused guide surfaces.

[0030] The indexable guide plates known from the prior art have only two guide surfaces on the upper side arranged opposite the support surface, so that the guide plate must be turned over by 180°. The guide plate is smaller and therefore the number of guide surfaces is greater. This increases the efficiency of the indexable guide plate according to the invention.

[0031] The indexable guide plate according to the invention is made of a hard material, such as sintered carbide, cermet or ceramic, which can be provided with an additional hard material layer to extend the service life. If one guide surface is worn, the worn indexable guide plate can be rotated and turned over so that the unused guide surface is activated. Only when all guide surfaces are worn does the indexable guide plate have to be replaced with a new, unused indexable guide plate.

[0032] The indexable guide plate on which the invention is based is used in a drilling tool with at least one replaceable guide plate, the guide plate comprising a shaft, wherein at least one recess for accommodating the indexable guide plate according to any of the preceding claims is provided in the drill head and / or the shaft, and a central threaded hole is present in one or more recesses. By means of the central threaded hole, the indexable guide plate according to the invention can be fastened in the recess and, if necessary, rotated or turned over by loosening the fastening screw.

[0033] "Turning" in relation to the present invention means that the indexable guide plate is rotated about the longitudinal axis of the central hole by an angle The worn guide surface is deactivated and replaced by an unused guide surface.

[0034] “Rotation” in connection with the present invention means that in the embodiment according to claim 2, the “upper side” and the “lower side” of the indexable guide plate switch their positions and functions.

[0035] In order to achieve an optimal contact mode, the longitudinal axis of the cylindrical surface of the working guide surface and the longitudinal axis of the drilling tool enclose an angle β greater than or equal to 0°. The angle may be, for example, 0°≤β≤2°.

[0036] It has proven to be advantageous if at least one recess is designed to be complementary to the outer contour of the indexable guide plate. This ensures a form-fitting connection between the indexable guide plate and the recess. In order to be able to optimally transfer radial forces from the drilling tool to the working guide surface and from the working guide surface to the hole wall, the base of the recess is flat. In an alternative embodiment, it has also proven to be advantageous if radially extending ribs are formed in the recess and these ribs are complementary to the radially extending depressions of the indexable guide plate.

[0037] This makes it possible to use the flat base of the recess in the indexable guide plate according to claim 2 as a support surface. In this case, it is recommended that the upper side of the rib is also a flat surface in order to maximize the contact surface between the indexable guide plate and the rib.

[0038] The fact that the indexable guide plate rests on and is supported by the recess also ensures that the radial distance between the working guide surface and the longitudinal axis of the drill tool remains constant throughout the service life of the indexable guide plate. If the indexable guide plate rested on the surface of the guide surface on the "underside" in the insert seat instead of via the recess, this dimension would change as soon as the indexable guide plate was rotated, and the already inserted and worn guide surface would then serve as a support surface in the insert seat.

[0039] In an alternative embodiment according to claim 2, the transmission of radial forces from the drilling tool to the hole can be further improved if the strip is arranged orthogonally to one of the ribs and the upper side of the strip and the upper side of the rib lie in one plane. The strip supports the indexable guide plate in the region of the working guide surface and thereby increases the load-bearing capacity and reliability of the indexable guide plate according to the invention.

[0040] In order to make room for the strips, in a particularly advantageous embodiment of the invention one rib is shorter than the other ribs.

[0041] According to an advantageous development, an intermediate plate is provided which is flat on its underside and has ribs and strips formed on its upper side. The underside of the intermediate plate then rests on a flat support surface of the drilling tool and its upper side provides a support surface for the indexable plate. This variant is advantageous in terms of production technology. If a rib or strip on the upper side is damaged, the damaged intermediate plate can be easily replaced.

[0042] Further advantages and advantageous embodiments of the invention can be found in the following figures, their description and the claims.All features described in the figures, their description and the claims may be essential to the invention both individually and in any combination with one another. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In the attached figure:

[0044] Figure 1 is an exploded view of a countersunk boring head having a first embodiment of an indexable guide plate according to the present invention;

[0045] Figure 2 a), Figure 2 b) and Figure 2 c) is a different view of the first embodiment of the indexable guide plate;

[0046] Figure 3 is an exploded view of a drill bit having a second embodiment of an indexable guide plate according to the present invention;

[0047] Figure 4 Shows Figure 3 Details;

[0048] Figure 5 a) and Figure 5 b) are two views of an intermediate plate according to the invention;

[0049] Figure 6 shows different views of a second embodiment of an indexable guide plate 31 having six guide surfaces; and

[0050] Figure 7 A pull boring head with an indexable guide plate according to the invention is shown. DETAILED DESCRIPTION

[0051] As already mentioned at the beginning, the present invention relates to an indexable guide plate and an associated drilling tool. The present invention is not limited to a specific type of drilling tool. All drills, drilling tools and drill bits with exchangeable guide plates or guide blocks can be equipped with an indexable guide plate according to the present invention. In particular, the present invention is suitable for BTA drill bits, ejector drill bits, but also for single-edge drill bits and double-edge drill bits. The present invention can also be used in particular on drilling tools for reaming. In short: the present invention can be used on all drilling tools with guide plates or guide blocks.

[0052] Since the invention relates to guide plates or guide pads of a drill, the cutting edge geometry and other details of the drill which are not essential to the invention will not be discussed. With regard to the invention, it is only important that there is a drill head with one or more receptacles for an indexable guide plate according to the invention.

[0053] Figure 1is an isometric view of a countersunk boring head. The countersunk boring head comprises a drill head 1 and a blade 5 which is fastened in a suitably shaped recess by means of a fastening screw 7. In this embodiment, three indexable guide plates 3 are arranged at the front end of the drill head 1 so as to be distributed over the circumference. One of the guide plates is shown in an exploded view in such a way that a recess 9 for accommodating the indexable guide plate 3 can be seen. The recess 9 has a flat base 11. An internal thread 13 is arranged approximately in the middle of the base 11. The indexable guide plate 3 is fixed in the recess 9 and pressed against the base 11 by means of a screw 15 screwed into the internal thread 13. The internal thread 13 can be positioned slightly outside the middle so that when the screw 15 is tightened, the indexable guide plate 3 is pressed laterally against the wall of the recess 9.

[0054] Figure 2 In three different views ( Figure 2 a: top view; Figure 2 b: isometric view; Figure 2 c: Side view) shows the indexable guide plate 3. Based on these views, the geometry and shape of a first embodiment of the indexable guide plate 3 according to the invention will be explained below.

[0055] As can be seen from the top view ( Figure 2 As can be seen from a), the indexable guide plate 3 is designed to be rotationally symmetrical. The center point S is located on the longitudinal axis of the central fastening hole 17, which is designed as a stepped hole. Figure 1 ) has a countersunk head, so the upper part of the fastening hole 17 is designed as a truncated cone.

[0056] With regard to the present invention, for the sake of simplicity of language, the indexable guide plate 3 is associated with a lower side and an upper side opposite the lower side. The lower side is the side of the indexable guide plate 3 that rests on the base 11 of the recess 9 in the installed state. In this embodiment, three approximately triangular guide surfaces 19 are formed on the upper side. As can be seen from the top view ( Figure 2 a) and isometric view ( Figure 2 b) It can be clearly seen that in this embodiment there are three radially extending depressions 21 between the guide surfaces 19. Therefore, the guide surfaces 19 do not merge directly into each other. This facilitates the creation of curved guide surfaces 19. However, a design without depressions between the guide surfaces 19 is also possible.

[0057] In this embodiment, the guide surfaces 19 have a cylindrical shape, wherein the longitudinal axes of these cylindrical surfaces do not extend parallel to the underside of the indexable guide plate 3, but rise slightly inwards, i.e. towards the fastening hole 17. The underside is the support surface 23 of the indexable guide plate 3 in the recess 9.

[0058] It can also be clearly seen from the top view that the indexable guide plate 3 has a hexagonal base, but in this embodiment it is not a regular hexagon with six equal sides. There are three longer sides and three shorter sides to prevent the indexable guide plate 3 from being installed incorrectly. The recess 21 extends towards the middle of the shorter sides. This situation can also be described in the following way: the radius R from the center point S to the edge 25 of the indexable guide plate 3 encloses an angle α different from zero with the longitudinal axis 27 of the recess 21. In the embodiment shown, this angle α is slightly less than 30°.

[0059] Because the three guide surfaces 19 and the three recesses 21 are Figure 2 In the embodiment shown, the arrangement is rotationally symmetrical, so that the longitudinal axes 27 of the two recesses 21 are each arranged at an angle of 120° relative to one another. This means that by tilting the indexable guide plate 3 through 120° in the recess, a worn guide surface 19 can be replaced by an unused guide surface 19 .

[0060] When watching Figure 1 This becomes slightly clearer when . When the indexable guide plate 3 is inserted into the recess 9 and the screw 15 is tightened, the guide surface indicated by 19.1 works. As soon as this guide surface 19.1 is worn, the screw 15 is loosened, the indexable guide plate 3 is removed from the recess 9, rotated 120°, then reinserted into the recess 9 and tightened with the screw 15. The guide surface 19.1 then no longer works, while one of the other two guide surfaces 19 works. This process can be repeated twice until all three guide surfaces 19 are worn. The indexable guide plate 3 can then no longer be used and must be replaced by a new indexable guide plate 3.

[0061] If you can Figure 2 As can be seen, chamfers 28 are formed on the outer edges of the guide surfaces 19. These chamfers 28 prevent the guide surfaces 19 from coming out and serve as guide chamfers when entering the created hole or point drilling guide to prevent jamming.

[0062] The longitudinal axis of the fastening hole 17 is indicated by 29 .

[0063] Back to Figure 1 It is clear that the recess 9 has a shape that corresponds to the hexagonal outer contour of the indexable guide plate 3. Undercuts are milled at the corners. This ensures that there is no jamming between the edge of the indexable guide plate 3 and the complementary corner of the recess 9. In addition, it is ensured that the transmission of forces between the drill bit 1 and the indexable guide plate 3 takes place on the surface and not linearly in the edge region.

[0064] The recess 9 opens on the end face of the drill bit 1. This makes it easier to insert and remove the indexable guide plate 3 into and from the recess. Otherwise, it would usually be difficult to remove the indexable guide plate 3 from the recess 9 because the plate is inserted into the recess 9 with little play.

[0065] Figure 3 Shown with Figure 1 Similar drill bits. Figure 3 3 is an exploded view of a second embodiment of an indexable guide plate 31 combined with an intermediate member 33. The indexable guide plate 31 and the intermediate member 33 can be used as Figure 1 and Figure 2 An important difference between the indexable guide plate 31 and the indexable guide plate 3 is that a total of six guide surfaces are formed here; three on the upper side and three on the lower side.

[0066] Figure 4 Shows an enlarged Figure 3 Detail X. The indexable guide plate 31 has an outer contour in the shape of a regular hexagon, so that all six sides have the same length.

[0067] The upper and lower sides of the indexable guide plate 31 are of the same shape. However, the recess 21 on the upper side of the indexable guide plate 31 and the recess 21 on the lower side (not visible) and the guide surface 19 are arranged to be rotated by 60° relative to each other (corresponding to the angle ).

[0068] Detail X makes it clear that the recess 21 is T-shaped at its radially outer end. The crossbars of this "T" extend parallel to the edge of the indexable guide plate 31. One of the crossbars is at Figure 4 Indicated by reference numeral 35.

[0069] The bases of the T-shaped recesses 21 are flat, ie they lie in a common plane and form a support surface 37 which interacts with the intermediate piece 33 .

[0070] exist Figure 5 In the top view ( Figure 5 a) and side view ( Figure 5 b) shows an intermediate piece 33. The intermediate piece 33 also has a hexagonal profile and a through hole 39 in the middle. Three ribs 41 are formed on the upper side of the intermediate piece 33, corresponding to the number of recesses 21 in the indexable guide plate 31. One rib 41.1 is shorter than the other two ribs 41. A strip 43 is formed orthogonally to the short rib 41.1 along the edge or border of the intermediate piece 33. As can be seen from Figure 5 b, the upper side 42 of the rib 41 and the upper side of the strip 43 are arranged in one plane. They form a seat for the support surface 37 at the base of the recess 21 of the indexable guide plate 31.

[0071] A recess 21 rests with its T-shaped crossbar 35 on the strip 43 so that the “working” guide surface 31 situated there is optimally supported on the upper side.

[0072] If you can Figure 3 and Figure 4 As can be seen, the intermediate piece 33 is preferably inserted into the recess 9 in such a way that the strip 43 is positioned at the front end of the drill 1. When the drill is in use, the guide surface 19 located there is active. Via the crossbars 35 and the strips 43, the radial forces transmitted from the drill 1 to the hole are transmitted in the best possible way and via the shortest route.

[0073] The strip 43 thus ensures that the working guide surface 19 is supported in the best possible manner despite the contact surface between the indexable guide plate 31 and the intermediate piece 33 being smaller than the contact surface between the underside 23 of the indexable guide plate 3 and the base 11 according to the first embodiment.

[0074] However, the indexable guide plate 31 according to the second embodiment can be loaded in the same way. The main advantage of the design according to the second embodiment of the indexable guide plate 31 can be seen from the fact that it has twice as many guide surfaces; in the case of a hexagonal outer contour, there are six guide surfaces. If the outer contour of the indexable guide plate is an octagon, even eight guide surfaces can be integrated into one indexable guide plate.

[0075] Figure 6 Different views of an indexable guide plate 31 according to a second embodiment are shown in detail. This results in a very good geometry of the indexable guide plate according to the invention.

[0076] Figure 7 An example of a further drill head 1 is shown, in which an indexable guide plate 3 or 31 can be used.

[0077] Reference numerals list

[0078] 1 Drill

[0079] 3 Indexable guide plate

[0080] 5 Blades

[0081] 7 Fastening screws

[0082] 9 recess

[0083] 11 Base

[0084] 13 Internal thread

[0085] 15 Screws

[0086] 17 Fastening hole (step hole)

[0087] 19 Guide surface

[0088] 21 Depression

[0089] 23 Underside of indexable guide plate

[0090] 25 Corner of indexable guide plate

[0091] 27 Longitudinal axis of the recess 21

[0092] 28 Chamfer

[0093] 29 The longitudinal axis of the fastening hole 17

[0094] 31 Indexable guide plate

[0095] 33 Middleware

[0096] 35 horizontal bars

[0097] 37 Support surface (at the base of the recess 21)

[0098] 39 holes

[0099] 41 Rib

[0100] 42 Upper side of rib 41 and strip 43

[0101] 43 articles

Claims

1. An indexable guide plate (3, 31) for use in a drilling tool, wherein: The indexable guide plate (3, 31) has two side surfaces and a central fastening hole (17), wherein the lower side is designed as a support surface (23), and wherein the upper side is opposite to the lower side and is provided with a plurality of guide surfaces (19, 19.1), wherein the indexable guide plate (3, 31) is rotationally symmetrical with respect to the longitudinal axis (29) of the fastening hole (17), characterized in that the support surface (23) is flat, wherein the outer contour of the indexable guide plate (3, 31) has a hexagonal shape, wherein the hexagon alternately has three long sides and three short sides, wherein three guide surfaces (19, 19.1) are provided, wherein each of the three guide surfaces (19, 19.1) is radially limited by the fastening hole (17) and one of the three long sides.

2. The indexable guide plate (3, 31) according to claim 1, characterized in that: The guide surfaces (19.1, 19) are curved.

3. The indexable guide plate (3, 31) according to claim 2, characterized in that: The guide surface (19.1, 19) is designed as a cylindrical surface, and the longitudinal axis of the cylindrical surface extends adjacent to the longitudinal axis of the drilling tool.

4. The indexable guide plate (3, 31) according to claim 1, characterized in that: The longitudinal axis of a guide surface (19, 19.1) and the support surface (23) enclose an angle of from 3° to 15°.

5. The indexable guide plate (3, 31) according to claim 1, characterized in that: By flipping the angle by 120° Each guide surface (19, 19.1) can be made to coincide with another guide surface (19, 19.1) on the side of the indexable guide plate (3, 31) opposite to the support surface (23).

6. An indexable guide plate (3, 31) for use in a drilling tool, wherein: The indexable guide plate (3, 31) has two side surfaces and a central fastening hole (17), wherein a support surface (37) and a plurality of guide surfaces (19, 19.1) are formed on each side surface, wherein the indexable guide plate (3, 31) is rotationally symmetrical with respect to the longitudinal axis (29) of the fastening hole (17), wherein the guide surfaces (19, 19.1) on one side surface of the indexable guide plate (3, 31) are separated from each other only by radially extending recesses (21), and wherein the base of these recesses (21) is designed as a flat support surface (37), characterized in that the recesses (21) are T-shaped at their radial outer ends.

7. The indexable guide plate (3, 31) according to claim 6, characterized in that: The longitudinal axis (27) of the recess (21) and the radius beam (R) pointing from the center point (S) to the corner of the outer contour (25) enclose an angle α different from zero degrees.

8. The indexable guide plate (3, 31) according to claim 6, characterized in that: The guide surfaces (19.1, 19) are curved.

9. The indexable guide plate (3, 31) according to claim 8, characterized in that: The guide surface (19.1, 19) is designed as a cylindrical surface, and the longitudinal axis of the cylindrical surface extends adjacent to the longitudinal axis of the drilling tool.

10. The indexable guide plate (3, 31) according to claim 6, characterized in that: The longitudinal axis of a guide surface (19, 19.1) and the support surface (23) enclose an angle of from 3° to 15°.

11. The indexable guide plate (3, 31) according to claim 6, characterized in that: By flipping the angle by 120° Each guide surface (19, 19.1) can be made to coincide with another guide surface (19, 19.1) on the side of the indexable guide plate (3, 31) opposite to the support surface (23).

12. A drilling tool comprising the indexable guide plate (3, 31) according to claim 1, and further comprising a shaft, a clamping end, a drill bit having at least one cutting edge and a longitudinal axis, wherein: At least one recess (9) for accommodating the indexable guide plate (3, 31) is provided in the drill bit (1) and / or the shaft, and wherein a threaded hole having an internal thread (13) at least approximately in the center is present in the recess (9), characterized in that the shape of the at least one recess (9) is a hexagon having three long sides and three short sides alternately and is complementary to the hexagonal outer contour of the indexable guide plate (3, 31), and wherein the recess (9) comprises a flat base (11) on which a support surface (23) of the indexable guide plate (3, 31) rests.

13. The drilling tool according to claim 12, characterized in that Radially extending ribs (41) are formed in the at least one recess (9), which are complementary to the radially extending recesses (21) of the indexable guide plate (3, 31), and the upper side (42) of the ribs (41) is flat and the upper side (42) of the ribs (41) is in one plane.

14. The drilling tool according to claim 12, characterized in that The longitudinal axis of the cylindrical surface of the indexable guide plate (3, 31) and the longitudinal axis of the drilling tool form an angle less than or equal to 2°.

15. The drilling tool according to claim 12, characterized in that The longitudinal axis of the cylindrical surface of the indexable guide plate (3, 31) and the longitudinal axis of the drilling tool form an angle less than or equal to 1°.

16. The drilling tool according to claim 13, characterized in that A strip (43) is arranged orthogonally to one of the ribs (41), and an upper side (42) of the strip (43) and an upper side (42) of the rib (41) lie in one plane.

17. The drilling tool according to claim 13, characterized in that One of the ribs (41) is shorter than the other ribs (41).

18. The drilling tool according to claim 12, characterized in that The support surface (23) of the indexable guide plate (3, 31) and the axis of the drilling tool form an angle of 3° to 15°.

19. The drilling tool according to claim 12, characterized in that The drilling tool is a single-edge deep hole drill or a double-edge deep hole drill.

20. A drilling tool having at least one indexable guide plate (3, 31) according to claim 1, further comprising a shaft, a clamping end, a drill bit having at least one cutting edge and a longitudinal axis, wherein: At least one recess (9) for accommodating the indexable guide plate (3, 31) is provided in the drill bit (1) and / or the shaft, and there is a threaded hole at least approximately in the center with an internal thread (13) in the recess (9), characterized in that the base (11) of the at least one recess (9) is flat, and an intermediate piece (33) is arranged in the recess (9), the outer contour of the intermediate piece (33) corresponds to the outer contour of the indexable guide plate (3, 31), and the lower side of the intermediate piece (33) is flat, and radially extending ribs (41) are formed on the upper side of the intermediate piece (33), which are complementary to the radially extending recesses (21) of the indexable guide plate (31), and the upper side (42) of the rib (41) is flat and the upper side (42) of the rib (41) is in a plane.

21. The drilling tool according to claim 20, characterized in that The longitudinal axis of the cylindrical surface of the indexable guide plate (3, 31) and the longitudinal axis of the drilling tool form an angle less than or equal to 2°.

22. The drilling tool according to claim 20, characterized in that The longitudinal axis of the cylindrical surface of the indexable guide plate (3, 31) and the longitudinal axis of the drilling tool form an angle less than or equal to 1°.

23. The drilling tool according to claim 20, characterized in that A strip (43) is arranged orthogonally to one of the ribs (41), and an upper side (42) of the strip (43) and an upper side (42) of the rib (41) lie in one plane.

24. The drilling tool according to claim 20, characterized in that One of the ribs (41) is shorter than the other ribs (41).

25. The drilling tool according to claim 20, characterized in that The support surface (23) of the indexable guide plate (3, 31) and the axis of the drilling tool form an angle of 3° to 15°.

26. The drilling tool according to claim 20, characterized in that The drilling tool is a single-edge deep hole drill or a double-edge deep hole drill.

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