Clamping device for fixing a tool disk to a machine tool, machine tool and fixing method

Abstract

The present invention relates to a clamping device for attaching a tool disc to a machine tool, wherein the clamping device comprises a screw that is screwed into a drive spindle of the machine tool to attach the tool disc. The screw is mounted in a coupling module of the clamping device, the coupling module having a first flange and inner contour, wherein the clamping device provides a positive-locking attachment of the tool disc to the machine tool, and wherein the second flange prevents the screw from loosening or tightening unintentionally. In further aspects, the invention relates to a machine tool with a drive spindle to which a tool disc can be attached using the proposed clamping device, and to a method for attaching a tool disc to such a machine tool.

Description

[0001] The present invention relates to a clamping device for fastening a tool disk to a machine tool, wherein the clamping device has a screw that is to be screwed into a drive spindle of the machine tool to fasten the tool disk. The screw is mounted in a coupling module of the clamping device, wherein the coupling module has a first flange and inner contour, wherein the clamping device effects a positive fastening of the tool disk to the machine tool and wherein the second flange prevents undesired loosening or tightening of the screw. In further aspects, the invention relates to a machine tool with a drive spindle to which a tool disk can be fastened with the aid of the proposed clamping device, as well as to a method for fastening a tool disk to such a machine tool. Background of the invention:

[0002] In the field of machine tools, cut-off and angle grinders are known, which use disc-shaped tools. Such disc-shaped tools, which are usually essentially circular, are referred to as tool, cutting, or grinding discs.

[0003] EP 4 227 040 A1 discloses a system for attaching a depressed-center grinding wheel, which can be connected, for example, to an angle grinder for grinding surfaces. A key advantage of the attachment system described in EP 4 227 040 A1 is that the tool wheel can be attached to or removed from the machine tool without the need for additional tools, i.e., "keyless."

[0004] Depressed-crank grinding wheels, such as those used in angle grinders, are generally cup-shaped so that the handle of the fastening system, as disclosed in EP 4 227 040 A1, can be accommodated in the recess of the depressed-crank grinding wheel. This shields the handle of the fastening system from the grinding wheel and prevents unwanted contact between the surface to be machined and the handle. Such contact can - depending on the direction of rotation of the grinding wheel - lead to the grinding wheel being tightened or released almost irreversibly. Both situations are obviously undesirable. If the grinding wheel is tightened almost irreversibly, considerable effort is often required to release the grinding wheel from the machine tool.If the grinding wheel comes loose when rotating in the opposite direction, there is a risk of injury to the user of the machine tool or bystanders.

[0005] If the tool disk of a machine tool has no countersink and no offset, no technical solutions are known in the state of the art to fasten a tool disk securely and keylessly to the machine tool on the one hand and to reliably prevent unwanted contact between a handle of the fastening system and the surface on the other.

[0006] The object underlying the present invention is to provide a system for fastening a tool disk to a machine tool, wherein the tool disk can also be uncranked, i.e., flat. The fastening system to be provided should, on the one hand, be secure and keyless, so that the user does not require any additional tools, such as wrenches or the like, to securely fasten the tool disk to the machine tool. On the other hand, even for uncranked, i.e., flat, tool disks, it should be ensured that the tool disk neither tightens almost irreversibly nor detaches from the machine tool during operation.

[0007] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the subject matter of the independent claims can be found in the dependent claims. Description of the invention:

[0008] According to the invention, a clamping device for fastening a tool disk to a machine tool is provided, wherein the clamping device has a screw that is to be screwed into a drive spindle of the machine tool to fasten the tool disk. The screw is mounted in a coupling module of the clamping device, wherein the coupling module has a first flange and an inner contour, wherein the clamping device ensures a positive fastening of the tool disk to the machine tool, and wherein the second flange prevents undesired loosening or tightening of the screw.

[0009] In accordance with the invention, it is preferred that the first flange is designed such that undesired loosening or tightening of the screw of the clamping device is prevented. This can then be achieved, for example, in that the first flange has a substantially circular base area, wherein the substantially circular base area is surrounded on its circumference by a side wall. In this case, the design of the first flange shields the screw or its operating element from the tool disk, so that contact between the operating element and the surface to be machined is effectively prevented. At the same time, the proposed clamping device further enables the tool disk to be fastened to the machine tool keyless, i.e. without the aid of another tool.Of course, the clamping device can have further optional features or components, some of which are known from EP 4 227 040 A1.

[0010] In an alternative embodiment of the invention, the first flange can have a base area that extends beyond the side walls of the first flange. The side walls of the first flange preferably form a collar that shields the operating element of the screw from the tool disk, so that touching or contact between the operating element and the surface to be machined is effectively prevented. The projecting areas of the base area ensure an enlargement of the contact area between the second flange and the tool disk, so that the forces can be better distributed when the screw of the clamping device is tightened. The flange can have an inner area that can be set back from an outer peripheral area. This can provide space for a retaining ring.In addition, the recessed inner area of ​​the flange allows a defined support area to be obtained on the outer diameter of the tool disk.

[0011] It has been shown that the provision of the first flange can prevent the screw from becoming almost irreversibly tightened or loosened, depending on the direction of rotation of the tool disk. This advantage is particularly possible for uncranked tool disks, which are not already protected from such unwanted contact by their design. Uncranked tool disks are particularly flat, so that they do not have a recess in which an operating element of the screw of the clamping device can be accommodated. In the context of the proposed clamping device, this function is performed by the first flange, which can have side walls to shield the operating element from the tool disk.The first flange can preferably also be referred to as an "outer flange" within the meaning of the invention, because in the attached state, for example, during operation of the machine tool, the first flange is arranged on the side of the tool disk facing away from the machine tool. Preferably, the first flange or its base surface can have different sizes or diameters. This advantageously allows tool disks of different sizes to be attached to the machine tool using the clamping device.

[0012] The inner contour of the clamping device can advantageously bring about a particularly stable, positive-locking fastening of the tool disk to the machine tool. The inner contour can preferably be designed as a dihedron or have a dihedron. The inner contour of the clamping device allows the tool disk to be fastened to the machine tool, in particular keyless, i.e. without tools. The inner contour preferably has an inner profile that can interact with a drive spindle of the machine tool to create a particularly stable, positive-locking shaft-hub connection. The shaft-hub connection created in this way exists in particular between the drive spindle of the machine tool and the screw of the proposed clamping device, wherein the screw of the clamping device is screwed into the drive spindle of the machine tool.The screw is guided through the inner contour and the first flange of the clamping device, as well as through the tool disk. The drive spindle of the machine tool can preferably be flattened on two sides. In the context of the machine tool, the spindle preferably represents an output shaft with which the tool disk of the machine tool can be driven. According to the invention, it is preferred that the shaft-hub connection enables rotational drive, so that the rotational movement of the drive spindle of the machine tool can be transmitted to the machine tool.

[0013] The invention advantageously provides a tool-free cutting disc attachment for cutting devices or cutting grinders, such as gas saws, angle grinders, and / or cordless cutting devices, without being limited thereto. A further advantage of the invention is that the clamping device can be particularly easily adapted to different sizes or diameters of tool discs by using different first flanges. In particular, the invention can prevent unwanted contact between the operating element of the clamping device or the screw and the surface, thereby advantageously preventing unintentional loosening or tightening of the screw during operation of the machine tool.

[0014] Compared to the fastening system described in EP 4 227 040 A1, the proposed clamping device has an outer flange that can be arranged directly or indirectly between the screw and the tool disk. The outer flange, which in the context of the present invention is referred to as the "first flange," is preferably designed to ensure that no unwanted contact occurs between the operating element and the substrate. This advantageously prevents the screw of the clamping device from loosening or becoming almost permanently tightened during operation of the machine tool. The first flange can be provided as a separately mounted component of the clamping device, so that it can be offered in various sizes to fasten or clamp different sized tool disks to the machine tool.The clamping device can preferably comprise a tool-free socket, which preferably represents a clamping element within the meaning of the invention. The preferably tool-free socket, which is also referred to as an "inner contour" within the meaning of the invention, preferably has an M8 thread and can be designed as a double flat.

[0015] Within the meaning of the invention, it is particularly preferred that the first flange is permanently or essentially permanently connected to the clamping device or the inner contour of the clamping device. The connection of the inner contour and the first flange forms a coupling module with which the tool disk can be fastened to the machine tool. The provision of the coupling module, which comprises the inner contour and the first flange, advantageously enables both the attachment of the tool disk to the machine tool and the attachment of the flange required for this purpose. The components of the proposed clamping device can be provided in different designs and sizes in order to be able to mount different sized tool disks, flanges and / or types of tool disks.According to the invention, it is preferred that the inner contour and the screw form a subassembly that can be passed through an opening in the first flange. In other words, the opening in the first flange and the outer diameter of the inner contour of the clamping device are designed such that the subassembly consisting of the inner contour and the screw can be inserted through the opening in the first flange. The screw can then be passed through a central opening in the tool disk and screwed into the drive spindle of the machine tool. For this purpose, the drive spindle can have an internal thread at the end into which the screw or the subassembly consisting of the inner contour and the screw can be screwed. The screw of the clamping device is mounted in a coupling module, the coupling module having the first flange and the inner contour.

[0016] According to the invention, it is preferred that the first flange has an opening and a base surface. The first flange preferably has a substantially circular base surface, with the opening of the first flange preferably being arranged centrally, i.e. in the middle, in the first flange. The base surface can in particular be flat. If the base surface of the first flange is flat or substantially flat, according to the invention, it is preferred that the first flange has a side wall which runs on a circumference of the first flange and preferably ensures that the first flange has or assumes a pot-like shape. The first flange preferably has a substantially circular base surface, with the substantially circular base surface being surrounded on its circumference by a side wall.The base and side walls of the first flange shield the operating element of the screw or clamping device from the tool disk, thus preventing contact between the operating element and the surface being machined. In other words, the base and side walls of the first flange are designed to shield the operating element of the screw or clamping device from the tool disk, preventing contact between the operating element and the surface. This advantageously prevents the screw from tightening or loosening undesirably.

[0017] It is preferred in the sense of the invention that the screw has an operating element, as well as a thread and a screw head and a bearing surface for contacting the first flange. The operating element can preferably be designed as a hand knob or a toggle. In order to fasten the tool disk to the machine tool or its drive spindle, the user can grip the screw at its operating element and tighten it. This advantageously causes an axial clamping of the tool disk to the drive spindle of the machine tool, wherein this fastening can advantageously be carried out without the aid of another tool, such as a wrench or the like. Thus, the invention can provide a tool-free, i.e.Keyless fastening of a tool disc to a machine tool is made possible, while at the same time ensuring that there is no contact between the screw operating element and the surface to be machined, even for flat tool discs. This allows the tool disc to be fastened to the machine tool without the use of tools using the proposed clamping device, while at the same time ensuring that the screw of the clamping device does not become almost irreversibly tight or undesirably loosen during operation of the machine tool. This makes it possible to provide a machine tool that is safe to operate and easy to handle, especially when flat tool discs are used.

[0018] In addition to the operating element, the screw can have a screw head. The screw head can, for example, be contained or countersunk in the operating element (see figures). For example, the head of the screw can have a hexagonal or hexagonal shape. In addition to the operating element and the screw head, the screw can have a support surface for contacting the first flange. The support surface of the screw can enlarge the contact area between the screw and the first flange, whereby the support surface of the screw is preferably in contact with the base surface of the first flange. This allows the forces resulting from tightening or tightening the screw in the internal thread of the drive spindle of the machine tool to be distributed over a larger area, thereby providing a particularly stable and smooth-running attachment of the tool disk to the machine tool.The screw may also have a thread that allows it to be screwed into the internal thread of the drive spindle. The screw thread is preferably designed as an external thread.

[0019] According to the invention, it is preferred that the screw does not directly contact the first flange. Preferably, a ball bearing and / or a bearing ring can be provided between the screw or its bearing surface and the first flange. Preferably, the contact between the bearing surface of the screw and the first flange can be direct or indirect. The term "direct contact" according to the invention preferably means that there is contact in the sense of a touch between the bearing surface of the screw and the first flange. In contrast, the term "indirect contact" according to the invention preferably means that additional objects, such as the bearing ring or a ball bearing, are arranged between the screw and the first flange, thus preventing direct contact between the screw and the first flange.

[0020] It is preferred according to the invention that the clamping device has a second flange, which, in a fastened state, is arranged between the drive spindle and the tool disk. The second flange can also be referred to as an "inner flange" according to the invention, because, in the fastened state—for example, during operation of the machine tool—the second flange is arranged on the side of the tool disk facing the machine tool. The clamping device is particularly designed to clamp the tool disk axially to the machine tool or its drive spindle. The tool disk can be fastened to a second flange associated with the drive spindle of the machine tool, with the clamping device having a screw that can be screwed into a drive spindle of the machine tool to clamp the tool disk.The second flange preferably has a support surface and a centering feature. In the fastened state, for example when the machine tool is in operation, the support surface of the second flange is arranged on the inside of the tool disk, wherein the inside of the tool disk is preferably the side of the tool disk facing the machine tool. The centering feature of the second flange preferably represents a central opening, which is preferably designed such that it can accommodate the inner contour of the clamping device. According to the invention, it is preferred that the support surface of the second flange enlarges the contact area between the second flange and the tool disk, wherein the support surface is in particular in contact with the inside of the tool disk.This allows the forces generated by tightening or tightening the screw in the internal thread of the machine tool's drive spindle to be distributed over a larger area, providing a particularly stable and smooth-running attachment of the tool disk to the machine tool. The second flange and the drive spindle preferably form the machine tool's tool holder to accommodate the tool disk.

[0021] It is preferred in the sense of the invention that the first flange, in a fastened state, is arranged directly or indirectly between the tool disk and the screw. If the first flange is arranged directly between the tool disk and the screw, there are preferably no further, optional components arranged between the first flange and the tool disk and the first flange and the screw or its support surface. If the first flange is arranged indirectly between the tool disk and the screw, a snap ring, for example, can be arranged as an additional, optional component of the clamping device between the tool disk and the screw or its support surface. In other words, the clamping device can have a snap ring arranged between the tool disk and the second flange.The snap ring can be configured to connect the clamping device to the outer flange. This advantageously prevents the outer flange from being lost when not in use by the user. For example, the first flange can be pressed on directly, or press rings, nuts, grub screws, and / or cross pins can be used for fastening, but are not limited to these. The first flange can also be caulked without rivets.

[0022] In a second aspect, the invention relates to a machine tool, preferably in the form of a cut-off grinder, wherein the machine tool has a drive spindle and a proposed clamping device. The clamping device is designed to fasten a tool disk to the drive spindle of the machine tool. The terms, definitions, and technical advantages introduced for the clamping device preferably apply analogously to the operating method for the machine tool. The drive spindle has an internal thread at its end, which can be connected to the screw of the clamping device in order to fasten the tool disk to the drive spindle of the machine tool. The internal thread of the drive spindle is designed, in particular, to receive the screw of the clamping device.This means that the screw of the clamping device can be screwed into the internal thread of the drive spindle in order to fasten the tool disk to the machine tool or to clamp the tool disk axially to the machine tool. According to the invention, it is preferred that the drive spindle be flattened on two sides. The drive spindle can preferably have an outer contour that can be connected to the inner contour of the coupling module in a form-fitting manner in the circumferential direction so as to prevent rotation. It has proven advantageous if the machine tool comprises a second flange that is or can be connected to the drive spindle in a form-fitting manner in the circumferential direction so as to prevent rotation.

[0023] In a further aspect, the invention relates to a method for attaching a tool disk to a machine tool. The terms, definitions, and technical advantages introduced for the clamping device and the machine tool preferably apply analogously to the fastening method. The method for attaching the tool disk to the machine tool is characterized by the following method steps: a) Providing a proposed clamping device, b) Screwing the screw of the clamping device into a drive spindle of the machine tool, wherein the screw is guided through an inner contour and a first flange of the clamping device, as well as through the tool disk. It is particularly preferred according to the invention that the screw is screwed into an end-side internal thread of the drive spindle. The method can, on the one hand, enable a tool disk to be securely and keylessly fastened to a machine tool and, on the other hand, prevent unwanted contact between a handle of the fastening system and the surface to be machined. This advantageously ensures that the The screw of the clamping device is not tightened to an almost irreversible level or the screw connection comes loose when the tool disk is rotated in the corresponding direction.

[0024] The clamping device according to the invention has the advantage that the screw of the clamping device can neither tighten nor loosen during operation of the machine tool because the coupling module, as part of the clamping device, is paired with the drive spindle in a form-fitting and anti-rotation manner. It has proven advantageous if the inner contour of the coupling module is designed as a double flat with an M8 thread. Preferably, the drive spindle of the machine tool has a corresponding outer contour that is designed to accommodate the inner contour and / or the screw of the clamping device. Alternative form-fitting, anti-rotation pairings, for example in the form of a form-fitting shaft-hub connection, can also be used. According to the invention, it is preferred that the inner contour or the double flat can be milled using a standard M14 angle grinder chuck.

[0025] The internal thread of the drive spindle is preferably an end-side internal thread. The internal thread can be set back in the axial direction relative to a head surface of the drive spindle. The screw preferably projects axially beyond the coupling module, in particular relative to a cylindrical section of the coupling module. The coupling module is preferably cylindrical. The coupling module preferably has a cylindrical section that can protrude through a central opening in the tool disk. The cylindrical section of the coupling module can protrude into a central opening in the first flange.

[0026] In a preferred embodiment, the clamping device has a handle that is formed with the screw in a circumferentially positive, rotationally secure manner. The handle can form an operating element, whereby in the context of the invention, reference is preferably also made to the "operating element of the screw" or the "operating element of the clamping device." This enables particularly simple handling of the clamping device. An additional assembly tool, such as an assembly wrench, can be dispensed with. The clamping device thus enables, in particular, tool-free, i.e., keyless, fastening of the tool disk to the machine tool.

[0027] Further advantages emerge from the following description of the figures. The figures, the description, and the claims contain numerous features in combination. The skilled person will also expediently consider the features individually and combine them into further meaningful combinations.

[0028] In the figures, identical and similar components are numbered with the same reference numerals.

[0029] They show: Fig. 1View of a preferred embodiment of the fastening system Fig. 2View of a second preferred embodiment of the fastening system Fig. 3View of a further preferred embodiment of the fastening system Fig. 4View of a further preferred embodiment of the clamping device, wherein the screw has a protruding area as a centering aid. Examples of implementation and description of figures:

[0030] The figures show preferred embodiments of the proposed fastening system. Figure 1The fastening system shown comprises a clamping device 10 with which a tool disk 300 can be fastened or clamped to a drive spindle 20 of a machine tool 100 (not shown) by means of a coupling module 1. The coupling module 1 has a first flange 17 and an inner contour 16. The inner contour 16 and the first flange 17 each have central openings through which a screw 2 can be guided. The screw 2 has a screw head 12, an external thread 14 and a support surface 9. In addition, the clamping device 10 has an operating element 3, which can be arranged on the screw head 12 and is therefore referred to in the context of the present invention either as an "operating element of the clamping device" or as an "operating element of the screw". The operating element 3 can be designed as a hand knob or as a toggle.The user of the machine tool 100 can grip the operating element 3 and rotate it so that the tool disk 300 of the machine tool 100 can be loosened or tightened with the operating element 3 of the clamping device 10 without tools.

[0031] The first flange 17 has a central opening 4 for the passage of the screw 2, as well as a base or bottom surface 5. The base surface 5 is preferably substantially circular, so that the outer edge of the first flange 17 forms a substantially circular circumference. A side wall 6 can run along the circumference of the first flange 17, forming a collar of the first flange 17 and ensuring that the first flange 17 is cup-shaped. This embodiment of the invention is described in Figure 2 The Figure 2The embodiment of the invention shown can be used primarily for diameters of 60 millimeters (mm), for example for steel-bonded diamond cutting discs 300. Alternatively, the base surface 5 of the first flange 17 can protrude beyond the side wall 6. This embodiment of the invention is shown in Figure 3 The Figure 3The embodiment of the invention shown can be used primarily for diameters of 90 or 100 mm, for example for abrasive disks 300 for larger cut-off grinders 100. The diameter specifications mentioned here preferably relate to the diameter of the flanges 8, 17, wherein the flange diameters result from a predetermined ratio of the diameter of the tool disk 300 to the diameter of the flange 8, 17. Such a ratio can be 0.25, for example, and can be derived from approval standards or the like. For abrasive disks with a diameter of 350 mm, a predetermined ratio of 0.25 can, for example, result in a flange diameter of at least 87.5 mm. Such a flange diameter can, for example, be rounded up to 90 mm. Within the meaning of the invention, it can also be preferred that the flange diameter depends on a gear head size.This preferably applies in particular to tool disks 300 made of steel or to tool disks 300 that comprise steel.

[0032] Through these measures or structural configurations of the first flange 17, it is possible to shield the operating element 3 of the clamping device 10 from the tool disk 300. This prevents contact between the substrate and the operating element 3 of the clamping device 10 and ensures that the screw 2 of the clamping device 10 does not accidentally loosen during operation of the machine tool 100 or that the screw 2—when the tool disk 300 rotates in the opposite direction—tightens almost irreversibly.

[0033] The inner contour 16 of the coupling module 1 or the clamping device 10 can be designed as a tool-free nut and include an M8 thread. The inner contour 16 can in particular be designed as a double flat, wherein the screw 2 can be mounted in an interior space 15 of the inner contour 16. The screw 2 can be slightly longer than the outer walls of the inner contour 16, so that the screw 2 protrudes from the interior space 15 of the inner contour 16. The screw 2 can then advantageously also be used as a centering aid. In addition, a pin 18 can be provided at the end of the screw 2 as a further centering aid. This embodiment of the invention is described in Figure 4shown. The screw 2 can be guided through the opening 4 of the first flange 17 and through a central opening of the tool disk 300. The screw 2 can then be screwed into an internal thread 22 of the drive spindle 20 of the machine tool 100. This allows the tool disk 300 to be axially clamped to the drive spindle 20. A snap ring 7 can be provided between the first flange 17 and the tool disk 300.

[0034] A second flange 8 can be provided between the drive spindle 20 and the machine tool 100. The second flange 8 has a central opening, which, within the meaning of the invention, can preferably be referred to as a centering 13. Furthermore, the second flange 8 can have a support surface 11, which is in contact with the tool disk 300 when the tool disk 300 is attached to the machine tool 100. Furthermore, the second flange 8 can have a rotary drive, which is designed, for example, as a double flat or a hexagon.

[0035] Figure 4 shows a preferred embodiment of the clamping device 10, wherein the screw 2 has a protruding portion 18 as a centering aid. The protruding portion 18 can be designed, for example, as a pin. In addition, Figure 4 the thread 14 of the screw 2 is shown, as well as the operating element 3 of the clamping device 10 or the screw 2. In addition, Figure 4the outer flange 17 and the inner contour 16. List of reference symbols

[0036] 1 Coupling module 2 Screw 3 Operating element 4 Opening of the first flange 5 Base area of ​​the first flange 6 Side wall of the first flange 7 Snap ring 8 Second flange 9 Support surface of the screw 10 Clamping device 11 Support surface of the second flange 12 Head of the screw 13 Centering of the second flange 14 Thread of the screw 15 Interior of the inner contour 16 Inner contour 17 First flange 18 Projecting area as a centering aid 20 Drive spindle 22 Internal thread of the drive spindle 100 Machine tool 300 Tool disk of the machine tool

Claims

1. Clamping device (10) for fastening a tool disc (300) to a machine tool (100), wherein the clamping device (10) has a screw (2) which is to be screwed into a drive spindle (20) of the machine tool (100) in order to fasten the tool disc (300), characterized in that the screw (2) is mounted in a coupling module (1) of the clamping device (10), wherein the coupling module (1) has a first flange (17) and inner contour (16), wherein the clamping device (10) effects a positive fastening of the tool disk (300) to the machine tool (100) and wherein the second flange (17) prevents undesired loosening or tightening of the screw (2).

2. Clamping device (10) according to claim 1 characterized in that the first flange (17) has an opening (4), a base (5) and a collar-shaped side wall (6).

3. Clamping device (10) according to one of the preceding claims characterized in thatthe screw (2) has an operating element (3), as well as a screw head (12), a thread (14) and a bearing surface (9) for contacting the first flange (17).

4. Clamping device (10) according to one of the preceding claims characterized in that the clamping device (10) has a second flange (8) which is arranged in a fastened state between the drive spindle (20) and the tool disk (300).

5. Clamping device (10) according to claim 4 characterized in that the second flange (8) has a support surface (11) and a centering (13).

6. Clamping device (10) according to one of the preceding claims characterized in that the first flange (17) is arranged in a fastened state directly or indirectly between the tool disc (300) and the screw (2).

7. Clamping device (10) according to one of the preceding claims characterized in thatthe clamping device (10) has a snap ring (7) arranged between the tool disc (300) and the second flange (17).

8. Clamping device (10) according to one of the preceding claims characterized in that the inner contour (16) is formed by a dihedral.

9. Clamping device (10) according to one of the preceding claims characterized in that the screw (2) has a protruding area (18) which serves as a centering aid.

10. Machine tool (100), preferably in the form of a cut-off grinder, wherein the machine tool (100) has a drive spindle (20) and a clamping device (10) according to one of the preceding claims, wherein the clamping device (10) is designed to fasten a tool disk (300) to the drive spindle (20) of the machine tool (100), characterized in thatthe drive spindle (20) has an internal thread (22) at the end which can be connected to the screw (2) of the clamping device (10) in order to fasten the tool disk (300) to the drive spindle (20) of the machine tool (100).

11. Machine tool (100) according to claim 10 characterized in that the drive spindle (20) is flattened on two sides.

12. Method for fastening a tool disk (300) to a machine tool (100), wherein the Procedure which includes the following procedural steps: a) Providing a clamping device (10) according to one of claims 1 to 10, b) Screwing the screw (2) of the clamping device (10) into a drive spindle (20) of the machine tool (100), wherein the screw (2) is guided through an inner contour (16) and a first flange (17) of the clamping device (10), as well as through the tool disk (300).

13. Method according to claim 12 characterized in thatthe screw (2) is screwed into an internal thread (22) at the end of the drive spindle (20).

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