WO2007006395A2

WO2007006395A2 - Cutting tool

Info

Publication number: WO2007006395A2
Application number: PCT/EP2006/005840
Authority: WO
Inventors: Jürgen Daub; Alexander Jung
Original assignee: Walter Ag
Priority date: 2005-07-08
Filing date: 2006-06-19
Publication date: 2007-01-18
Also published as: DE102005031988B4; WO2007006395A3; WO2007006395A8; DE102005031988A1

Abstract

The cutting tool has an annular blade holder (4) which is preferably made of steel and carries cutting bodies made of a hard metal with a coating of mechanically resistant material, preferably a PCD coating. This blade ring (4) is held by a supporting body (3) which is preferably made of light alloy. It supports the blade ring (4) in both the axial and radial directions. Such a cutting tool has a reduced mass moment of inertia and can be used for high-speed machining, in particular at very high rotational speeds.

Description

Walter AG, Derendiner Str. 53, 72072 Tübingen

Zerspanunqswerkzeucr

The invention relates to a cutting tool, in particular a milling tool with a defined number of cutting edges.

Cutting tools usually have a tool body on which one or more cutting edges are arranged or formed. The tool body is doing the task of holding the cutting edges or cutting body in a desired position and thereby absorb the forces occurring on the cutting body. For this purpose, it is known to attach corresponding cutting body directly to the tool body releasably or permanently or to use the cutting body in cassettes that can be set separately and, if necessary, replaced individually. Cutting materials are increasingly being used, which enable extreme machining performance and maximum machining speeds. This leads to very high tool speeds, which the tool body has to cope with. In addition, there is a desire to reduce the weight of the tool body. On this basis, it is an object of the invention to provide an improved cutting tool.

This object is achieved with the cutting tool according to claim 1:

The cutting tool according to the invention has an annular blade carrier, are arranged on the cutting body. The annular blade carrier can, for example, be a steel ring with a relatively small cross-section. It is received by the support body, which ensures the shape retention of the cutter carrier and ensures that the cutting tool can be connected to a receptacle. For this purpose, the vaginal carrier is located on the support surface of the support body with its seat. The tangential forces acting on the cutter carrier with respect to the axis of rotation in the circumferential direction can not lead to deformation of the same due to the large compressive and tensile stiffness of the cutter carrier in the circumferential direction. With respect to deformations in the axial direction or optionally in radial directions, the blade carrier is supported on the support body, which thus provides the desired guidance.

The support body is preferably made of a light metal, such as aluminum, an aluminum alloy, magnesium or a magnesium alloy, although other dimensionally stable lightweight and solid materials can be used. The two-part constructed in this way and consisting of the blade carrier and the support body tool body has a low weight and provides high precision in terms of cutting edge positioning. This is especially true if the cutting body held inseparable on the blade carrier, that is, for example soldered with this or otherwise secured as material fit to this. The cutting bodies of the cutter carrier can, for example, be precision ground. The presented concept is particularly suitable for tools with PCD cutting edges or other precision machined hard material cutting edges. Due to the resulting low tool weight, it is possible to work with very high speeds and also with very high feed rates without endangering the tool, the machine or the personnel. The support body is provided with a coupling device which allows the connection to the work spindle of a machine tool. This coupling device can be a steep taper shank, which is formed directly on the support body or is connected to it via a suitable interface. It is possible to manufacture this coupling device again from another material or from the material of the Stützkδrpers. The supporting body and / or the coupling device can be provided with a suitable hard material layer, for example with an anodized layer. In addition to the advantage of increased surface strength results in the possibility of color designs.

The seat and the support surface are preferably cylindrical, closed, ie uninterrupted annular surfaces. However, it is also possible to provide these annular surfaces with recesses, openings and the like. The support surface and the seat surface Preferably, a fit that allows removal of the blade carrier from the support body and a sliding on the same. The support surface centers the cutter carrier. To secure the blade carrier to the support body is a connecting means, for example. In the form of bolts, which are screwed through the blade carrier axially penetrating into corresponding holes of the support body. The blade carrier is thus releasably held on the support body. It is also possible to fasten it inseparably, for example by a soldering or welding connection. Furthermore, it is possible to secure it by a press fit or a shrink fit on the support body. If the blade carrier is made of steel and the supporting body is made of aluminum, such a shrink fit can, if necessary, be produced by cold (liquid nitrogen) and possibly also dissolved.

The detachable mounting of the annular cutter carrier on the support body has the advantage that the cutting body of the cutter carrier can be reground. To compensate for the changed by the grinding axial position of the cutting body can then be used in the mounting of the cutter support on the support body a shim, for example. In the form of a shim or a Beilagerings that between an axial end face of the cutter support and an axial abutment surface of the support body is arranged. In this way, a reground tool is identical to a new tool in terms of the position of its end cutting edges. This facilitates the automated production with cutting tools, if they are subject to regrinding, in particular, when it comes to face milling.

To adapt to the regrind, Beilageringe be kept with different thicknesses. Furthermore, it is possible to provide for one and the same support body several cutting rings, which have the same or different dimensions. If they have the same diameter, a still unused cutter carrier can replace a worn one, which is then worked up in the meantime, for example reground. If cutter carriers with different diameters are available, different tools can be assembled with the same support body.

Further details of advantageous embodiments of the invention are the subject of the drawing, the description or subclaims.

In the drawings, embodiments of the invention are illustrated. Show it:

Fig. 1 A cutting tool of the invention type in a simplified perspective view;

FIG. 2 shows the cutting tool according to FIG. 1 in an exploded view; FIG.

3 shows a cutting tool according to the invention with a shrink connection between blade carrier and supporting body in a perspective view;

Fig. 4 shows the cutting tool of Figure 3 in exploded view and

Fig. 5 shows the cutting tool of Figure 1 or 3 in a sectional schematic representation with exaggerated Representation of the support surface and the Axialanlagefläche of the support body.

In Fig. 1, a cutting tool 1, designed as a face milling cutter, is illustrated, which, e.g. for light metal working (aluminum working). However, it can also be used in appropriate design for steel processing or cast machining.

The cutting tool 1 has a tool body 2, which is formed by a support body 3 and a blade carrier 4. The support body 3 is arranged concentrically to a rotation axis 5, which is determined by the work spindle of a not further illustrated machine tool. He also holds the blade carrier 4 concentric with the axis of rotation. 5

The blade carrier 4 is a closed ring, which, for example, consists of steel. He carries a number of cutting bodies 6 projecting both on its front face 7 and on its outer peripheral surface 8 and the cutting edges 9 (main cutting edges) are congruent with each other in the circumferential direction. The cutting edges 10 (minor cutting edges) lie on a common surface, e.g. one level. The cutting body 6 are preferably held firmly and permanently on the cutter support 4. For example. are the cutting body 6 carbide body with PCD (polycrystalline diamond). The carbide body are then soldered to the blade carrier 4.

The blade carrier 4 has, as is apparent in particular from Figure 2, a central opening which is bounded by a preferably cylindrical seat surface 11 which serves to center the cutter support 4. At its rear side remote from the end face 7, the blade carrier 4 has a preferably planar, annular end face 12 on, which serves for the correct axial positioning of the cutter carrier 4.

The support body 3 is also apparent from Figure 2. For centering of the cutter support 4 and optionally for its support, the support body 3 is provided with an extension 13, e.g. may be cylindrical or hollow cylindrical or similar. It has a support surface 14 which is associated with the seat surface 11 and has substantially the same diameter as the latter. To the support surface 14, an axial abutment surface 15 connects, which may be slightly inclined to the radial direction. Reference is made to FIG. The support body 3 here has an axial abutment surface 15, which is not quite flat but drops towards the axis of rotation 5. It thus forms a very shallow cone with defined abutment of the cutter support 4 at the outer edge of the axial abutment surface 15. Likewise, the support surface 14 may be made somewhat spherical. In addition, an insertion surface 16 can adjoin the support surface 14 in order to facilitate the sliding of the cutter support 4 onto the extension 13.

For attachment of the cutter support 4 to the support body 3 is a connecting means 17 in the form of one or more bolts 18. To accommodate the same 4 holes 19 are provided on the cutter support, which extend parallel to the axis of rotation 5 through the cutter support 4. They can be provided in equidistant angle sections or at unequal angular intervals.

Aligned to the holes 19 in the support body 3 threaded holes 20 are formed, which enforce the axial abutment surface 15. Furthermore, the blade carrier 4 and the support body 3 may be provided with fitting bores 21, 22, to which dowel pins 23 are assigned. The fitting holes 21, 22 and the dowel pins 23 are oriented parallel to the bolts 18. They can be arranged offset 180 ° to each other. Other angular orientations are possible to allow a unique angle assignment between the blade carrier 4 and the support body 3.

To the cutting tool 1 also includes a shim 24. This can be omitted if necessary. However, it is with holes 26 for. The insert element 24 has, for example, the shape of a shim 25 whose large central opening is slightly larger than the outer diameter of the extension 13 Receiving the bolt 18 and the dowel pins 23 provided. The outer diameter of the shim 25 is approximately equal to the outer diameter of the support body 3, which in turn coincides approximately with the outer diameter of the cutter support 4.

At its rear side, the support body 3 is provided with a coupling device 27 which, for example, can be designed as a standard interface for fastening a steep taper shank, which then in turn establishes the connection to a machine spindle. The support body 3 is preferably made of a light metal such as aluminum or the like. It can be completely or partially anodised.

The cutting tool 1 has the configuration according to FIG. 1 in the mounted state. It is used eg as a face milling cutter. The outgoing of the cutting edges 19 forces are first on the blade carrier 4 and this transferred to the support body 3. The support body 3 supports the blade carrier 4 both in the radial direction and in particular in the axial direction and thus prevents its deformation. The bolts 18 press the blade carrier 4 and the shim 25 against the axial abutment surface 15 and thus allow a frictional torque transmission between the blade carrier 4 and the support body. 3

The cutting tool 1 can be operated at a very high speed as a result of the axial alignment of the bolt 18, the risk that such triggers and causes damage banned.

During operation, the cutting edges 9, 10 of the cutting bodies 6 wear until they are worked up, e.g. must be reground. For this purpose, the blade carrier 4 is separated from the support body 3, in which the bolts 18 are released and the cutting ring 4 is withdrawn from the extension 13. It is now another not yet worn cutting ring 4 pushed onto the extension 13 and secured with the bolt 18 to the support body 3. The cutting tool 1 is thus immediately ready for use again.

For sharpening the cutting body 6 of the blade carrier 4, the cutting body 6 are ground on their exposed flanks. As a result, they stand in the sharpened state less far beyond the end face 7 and the outer peripheral surface 8. For the Planfräsvorgang in particular the malposition of the frontal cutting edge 10 meaning. This is now compensated, in which the existing shim 25 is replaced by the next thicker shim. The cutting tool 1 with the added Cutting is thus immediately operational again. No changes need to be made to the engine control program. The cutting edges of the reground cutting tool have the same axial positions as the cutting edges of still unused new cutting tools.

The proposed design of cutting tools with annular blade carrier 4 and consisting of light metal support body 3 is particularly useful in cutting tools with large diameter, where it depends all the more on low moment of inertia. Such a design of a cutting tool 1 is apparent from Figures 3 and 4. In FIGS. 3 and 4, the same reference numbers are used as for the description of FIGS. 1 and 2. The previous description applies accordingly. Deviating from this applies to the cutting tool 1 of Figures 3 and 4 that the blade carrier 4 has a particularly high degree of slenderness due to its large diameter. Its thickness measured in the radial direction is little more than twice to three times a cutting body 6. Also in the axial direction it is hardly longer than two to three times a cutting body 6. As a result of existing before the respective cutting body generous chip recess 28, the blade carrier 4 has a noticeable flexibility on. The stiffening required for operation causes the support body 3, which consists of aluminum or another light metal. With respect to the radial direction, the blade carrier 4 is supported by the seat surface 11 on the support surface 14. In the axial direction, it rests against the axial abutment surface 15 with its end face 12 hidden in FIG.

For fastening the blade carrier 4 on the support body 3, as in the previous embodiment, individual bolts are preferably used with axial orientation. However, it is also possible to connect the blade carrier 4 cohesively to the support body 3, for example by being hard-soldered, so that the soldering joint forms the connecting means 17.

Furthermore, it is possible to connect the blade carrier 4 by a shrink connection with the support body 3, which forms the connecting means 17. For this purpose, the extension 13 has a certain excess with respect to the blade carrier 4, i. the diameter of the support surface 14 is slightly larger than the diameter of the seat surface 11. The blade carrier 4 and the support body 3 are now joined by at least the support body 3 has been previously cooled. After reheating the support body 3 whose extension 13 sits firmly in the blade carrier. 4

If necessary, the joint connection can be designed such that it can be detached. For example, For example, the cutting tool 1 can be cooled with liquid nitrogen. As a result of the larger coefficient of thermal expansion of the support body (light metal) compared to the separator carrier 4 thereby the interference fit to the clearance and the blade carrier 4 can be removed. This is, for example, required to regrind the cutting edges 19 of the individual cutting bodies 6. Once this is done, the support body 3 and the blade carrier 4 are in turn joined, wherein for axial positioning of the cutting edges 10, one or more shims between the axial abutment surface 15 and the end face 12 can be placed.

The cutting tool according to the invention has an annular blade carrier 4, preferably made of Consists of steel and cutting body made of hard metal with a hard material Aufläge, preferably carries a PCD pad. This cutting ring is received by a support body 3, which preferably consists of light metal. He takes over the support of the cutting ring both in the axial direction and in the radial direction. Such a cutting tool has a reduced weight and consequently a reduced mass moment of inertia and can be used for high-speed machining, in particular at very high rotational speeds.

Claims

Claims:

1. cutting tool (1), in particular milling tool,

with an annular cutter carrier (4) which carries a number of cutting bodies (6) and which has a central opening with a seat surface (11),

with a support body (3) to be driven in rotation about a rotation axis (5), which has a support surface (14) associated with the seat surface (11) and a coupling device (27) for connection to a machine spindle, and

with at least one connecting means (17) for connecting the cutter carrier (4) to the supporting body (3).

2. Cutting tool according to claim 1, characterized in that the blade carrier (4) has an elastic deformability which is greater than permissible in view of the machining accuracy to be achieved and that the supporting body (3) has a rigidity which is so high that it prevents the deformation of the cutter carrier (4) during a cutting operation within the scope of the machining accuracy to be achieved.

3. Cutting tool according to claim 1, characterized in that the seat surface (11) is a cylindrical surface.

4. Cutting tool according to claim 1, characterized in that the support surface (14) has a cylindrical surface is.

5. Cutting tool according to claim 1, characterized in that adjoining the seat surface (11) and / or on the support surface (14) an insertion surface (16).

6. Cutting tool according to claim 1, characterized in that the supporting body (3) has an axial abutment surface (15).

7. Cutting tool according to claim 6, characterized in that the cutter carrier (4) has an axial contact surface (15) associated end face (12).

8. Cutting tool according to claim 1, characterized in that the blade carrier (4) consists of an iron alloy, a steel or a nickel-based alloy.

9. cutting tool according to claim 1, characterized in that the Schneidkόrper (6) are materially connected to the cutter support (4).

10. Cutting tool according to claim 1, characterized in that the cutting bodies (6) have hard material cutting.

11. Cutting tool according to claim 1, characterized in that the cutting bodies (6) have PCD cutting edges.

12. Cutting tool according to claim 1, characterized records that the support body (3) consists of a light metal or a light metal alloy.

13. Cutting tool according to claim 1, characterized in that the supporting body (3) is provided at least in one area with a hard material layer.

14. Cutting tool according to claim 13, characterized in that the hard material layer is an anodized layer.

15. Cutting tool according to claim 1, characterized in that the support surface (14) is aligned concentrically with the axis of rotation (5).

16. Cutting tool according to claim 1, characterized in that the connecting means (17) by bolts (18) is formed, which extend parallel to the axis of rotation (5) provided in the cutter support (4) openings (19) and in threaded holes (20) are screwed, which are formed in the support body (3).

17. Cutting tool according to claim 1, characterized in that between the blade carrier (4) and the supporting body (3) ^' at least one shim element (25) is arranged.

18. Cutting tool according to claim 1, characterized in that the shim element (25) is a shim.

19. Cutting tool set with a cutting tool according to one of the preceding claims, with at least one further blade carrier.

20. Cutting tool (1), in particular milling tool,

with at least one connecting means (17) for connecting the cutter carrier (4) to the supporting body (3), and

with at least one washer (25) disposed between the cutter support (4) and the support body (3).

21. Cutting tool (1), in particular milling tool,

with a support body (3) which is to be driven in rotation about a rotation axis (5) and has a support surface (14) associated with the seat surface (11) and a coupling device (27) for connection to a machine spindle, and

with at least one connecting means (17) for connecting the cutter carrier (4) to the supporting body (3),

wherein the cutting bodies (6) are soldered into the cutter support (4).