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CN-114683362-B - Milling tool and method for producing such a milling tool

CN114683362BCN 114683362 BCN114683362 BCN 114683362BCN-114683362-B

Abstract

The invention relates to a milling tool (1) for cutting wood or wood material and to a method for producing such a milling tool (1). The longitudinal direction (3), the radial direction (4) and the rotational direction (5) are predefined by the rotational axis (2) of the milling tool (1). The milling tool (1) comprises a basic body (6) and at least one cutting edge (7) adjoining a cutting face (8) directed forward in the direction of rotation (5) and a free face (9) directed outward in the radial direction (4). The cutting edge (7) and the cutting face (8) extend in a curved manner in the longitudinal direction (3). The curved cutting edge (7) and the curved cutting surface (8) are formed on a cutting insert (10) which is formed separately from the base body (6). The cutting blade (10) is fastened with its flat inner surface (20) and is welded in particular to a flat support surface (21) of the base body (6).

Inventors

  • O. Garry

Assignees

  • 德国莱德曼有限责任及两合公司

Dates

Publication Date
20260505
Application Date
20210924
Priority Date
20200924

Claims (18)

  1. 1. Milling tool (1) for cutting wood material, which is provided for being driven rotationally about a rotational axis (2), wherein a longitudinal direction (3), a radial direction (4) and a rotational direction (5) are predefined by the rotational axis (2), which milling tool comprises a basic body (6) and at least one cutting edge (7) arranged on the circumferential side of the basic body (6), wherein the cutting edge (7) adjoins a cutting face (8) pointing forward in the rotational direction (5) and a free face (9) pointing outward in the radial direction (4), and wherein the cutting edge (7) and the cutting face (8) extend curvedly in the longitudinal direction (3), The cutting blade (10) is formed from a composite material having a carrier layer (11) and a hard layer (12), wherein the cutting blade (10) has a flat inner surface (20) facing radially inwards towards the base body (6) opposite the free surface (9), wherein a flat support surface (21) corresponding to the flat inner surface (20) is formed on the base body (6), wherein the cutting blade (10) is fastened with its flat inner surface (20) to the flat support surface (21) of the base body (6), wherein the cutting blade (10) is formed from a composite material having a carrier layer (11) and a hard layer (12), wherein the carrier layer (11) of the cutting blade (10) is fastened to the base body (6) facing radially inwards in the radial direction (4), and wherein the hard layer (12) is located outside the carrier layer (11) in the radial direction (4) and forms the free surface (9).
  2. 2. The milling tool according to claim 1, Characterized in that the cutting blade (10) is welded with its flat inner surface (20) to a flat bearing surface (21) of the base body (6).
  3. 3. The milling tool according to claim 1, Characterized in that the milling tool has a milling section (22) having a cutting length (L) and a diameter (D), wherein the cutting length (L) is greater than half the diameter (D).
  4. 4. The milling tool according to claim 1, Characterized in that the milling tool has a milling section (22) having a cutting length (L) and a diameter (D), wherein the cutting length (L) is greater than the diameter (D).
  5. 5. The milling tool according to claim 1, Characterized in that the cutting blade (10) has a blade length (l) and a thickness (d), and the blade length (l) is greater than the thickness (d).
  6. 6. The milling tool according to claim 1, Characterized in that the milling tool has a milling section (22) having a cutting length (L), wherein the at least one blade (7) extends along the entire cutting length (L).
  7. 7. The milling tool according to claim 1, Characterized in that the at least one cutting edge (7) extends between two end points (23, 24), wherein the end points (23, 24) lie on a line parallel to the longitudinal direction (3).
  8. 8. The milling tool according to claim 1, Characterized in that the hard layer (12) is a PKD layer, a PVD layer or a CVD layer.
  9. 9. The milling tool according to claim 1, Characterized in that the cutting blade (10) is cut out of a flat composite blank (15) having a carrier layer (11) and a hard layer (12), such that the free face (9) is formed by the hard layer (12), an inner surface (20) opposite the free face (9) is formed by the carrier layer, and the cutting face (8) is formed by means of a cut (16) through the composite blank (15).
  10. 10. The milling tool according to claim 1, Characterized in that the cutting edge (7) and the cutting surface (8) extend in a curved manner, the cutting insert (10) has an abutment surface (13) opposite the cutting surface (8) with respect to the direction of rotation (5), and the abutment surface (13) is flat.
  11. 11. The milling tool according to claim 1, Characterized in that the cutting edge (7) and the cutting surface (8) extend in a curved manner, the cutting insert (10) has an abutment surface (13) opposite the cutting surface (8) with respect to the direction of rotation (5), and the cutting insert (10) has a constant width (b) between the cutting surface (8) and the abutment surface (13).
  12. 12. The milling tool according to claim 1, Characterized in that a contour (14) is machined into the free surface (9).
  13. 13. The milling tool according to claim 1, Characterized in that the base body (6) is formed from a different material than the cutting blade (10).
  14. 14. The milling tool according to claim 1, Characterized in that the milling tool (1) is used for cutting wood.
  15. 15. Method for producing a milling tool (1) for cutting wood material, wherein the milling tool (1) is provided for rotationally driving about a rotational axis (2), wherein a longitudinal direction (3), a radial direction (4) and a rotational direction (5) are predefined by the rotational axis (2), the milling tool comprising a basic body (6) and at least one cutting edge (7) arranged on the circumferential side of the basic body (6), wherein the cutting edge (7) adjoins a cutting face (8) pointing forward in the rotational direction (5) and a free face (9) pointing outward in the radial direction (4), and wherein the cutting edge (7) and the cutting face (8) extend in a curved manner in the longitudinal direction (3), wherein the curved cutting edge (7) and the curved cutting face (8) are formed on a cutting insert (10) which is formed separately from the basic body (6), wherein the cutting insert (10) is composed of a composite material with a carrier layer (11) and a hard layer (12), wherein the cutting insert (10) has a radially opposite inner surface (20) facing the free face (6), -forming a planar bearing surface (21) on the base body (6) corresponding to the planar inner surface (20), characterized by the following method steps: Separating a flat cutting blade (10) from the flat blank, said cutting blade having a curved extending cutting edge (7), a curved extending cutting face (8) and a flat inner surface (20), -The cutting blade (10) is fastened with its flat inner surface (20) and with its carrier layer (11) in a radial direction (4) directed inwards on a flat bearing surface (21) of the base body (6), wherein the hard layer (12) is located outside the carrier layer (11) in the radial direction (4) and forms the free surface (9).
  16. 16. Method according to claim 15, characterized in that the cutting insert (10) is brazed with its flat inner surface (20) to a flat bearing surface (21) of the basic body (6) pointing inwards in the radial direction (4).
  17. 17. The method according to claim 15, Characterized in that the cutting insert (10) is cut out of a flat composite blank (15) having a carrier layer (11) and a hard layer (12), such that the free surface (9) is formed by the hard layer (12), an inner surface (20) opposite the free surface (9) is formed by the carrier layer (11), and the curved cutting surface (8) is formed by means of a cut (16) through the composite blank (15), wherein the cutting insert (10) thus prepared is fastened to the base body (6) of the milling tool (1).
  18. 18. The method according to claim 15, Characterized in that the milling tool (1) is used for cutting wood.

Description

Milling tool and method for producing such a milling tool Technical Field The present invention relates to a milling tool for cutting wood or woody material and a method for manufacturing such a milling tool. Background A milling tool of this type is known from DE 10 2005 020 513 B3 in the form of an end mill having two concavely curved cutting edges and a concavely curved cutting face corresponding thereto. The two individual blades extend continuously and uninterruptedly over the entire cutting length. Such milling tools are used in particular for machining blade materials made of wood or wood materials, such as chipboard or fiberboard with or without a coating. The concavely curved edge causes cutting forces to be generated on both surfaces of the blade material, which cutting forces are directed towards the inside of the workpiece and thus avoid wear of the cutting edge. The milling tool shown overall comprises a basic body, a shank and a cutting edge which are embodied in one piece. In such a unitary tool, the choice of material is determined by the requirements for the blade. Thus, if a hard metal blade is desired, for example, for achieving a long service life, the whole of the end mill, including the shank, is made of flat hard metal. Such a tool can achieve good cutting quality and a long service life. However, various disadvantages must also be accepted. The shaping of the shank or the base body with the cutting groove or the like is costly. Concave blades can only be economically manufactured with rotating manufacturing tools (milling cutters, grinding wheels). The concave shape of the cutting face is determined by the smallest possible diameter of the manufacturing tool. Expensive hard metals are also used away from the blade edge, the material properties of which are not at all required or even hindered. The shank, which is made of hard metal, is sensitive to breakage and does not yet have a good damping characteristic. In sum, such tools are expensive. The use of harder cutting materials, such as PKD (polycrystalline diamond), is not possible in the monolithic designs described above depending on the current state. Furthermore, it is of course known to extend the possibilities of material selection by using separate cutting blades. The shank and the base of the milling cutter may for example be composed of tool steel, wherein hard metal or PKD inserts are then welded. Such a solution is known, for example, from WO 2012/163338 A1, wherein the tool base body is provided with a blade seat and a cutting space for each cutting blade. The flat blade seat stands upright, i.e. approximately radial to the rotation axis or transverse to the cutting direction. The associated cutting insert is welded with its flat rear side to the upstanding insert seat such that its opposite flat front side forms the likewise flat cutting face. In this configuration, no economically justified solution is known, i.e. a single cutting blade with a curved edge and cutting face course forms a single edge extending over the entire cutting length. For this purpose, the cutting blade, which is flat in its basic shape, must be concavely machined in the welded state on its initially flat front side. Since the front side is the entire PKD layer, this very hard and, in addition, very expensive material must be removed in large volumes. On the one hand, this would be premised on a corresponding thickness of the PKD layer, and on the other hand, would be practically unfeasible due to the expense. For the application mentioned at the outset, the combination of a concavely curved cutting edge and a concavely curved cutting surface disclosed in DE 10 2005 020 513 B3 is therefore approximated in the design according to WO 2012/163338 A1 by a plurality of rows of individual, planar cutting blades. For this purpose, the flat cutting insert is inclined with its flat cutting surface at an axial or oblique angle with respect to the longitudinal direction of the tool. The cutting face of the cutting blade positioned adjacent the shank is inclined toward the free tool end, while the cutting face of the cutting blade positioned adjacent the free tool end is inclined toward the shank. In other words, the end side cutting blades face each other. The same effect occurs during the machining of the workpiece as in the continuously curved edge path, so that in this case also cutting forces directed into the workpiece are generated on both surfaces of the blade material. However, such a construction also has the disadvantage that the cutting space and the insert seat must be milled into the tool base for each of the multitude of cutting inserts. The high material removal results in a weakening of the core of the base body in addition to the high effort. Thus, high quality, only difficult to cut materials must be used for the substrate. A disadvantage is also noted in operation, particularly in milling tools with small flight circle diameters, in which