METHOD FOR LASER-BASED GENERATION OF A STRUCTURE ON A RAKE FACE OF A CUTTING TOOL

Abstract

A method for the laser-based generation of a structure on a rake face of a cutting tool is disclosed, where at least one structure is formed by lines that are generated with a mutual spacing of at most 400 m with a laser beam at least in areas within a predetermined contour on at least one rake face of the cutting tool. A course of the lines forming the structure is oriented with respect to a profile of at least one cutting edge of the at least one rake face.

Claims

1. A method for the laser-based generation of a structure on at least one rake face of a cutting tool, comprising: defining a contour on at least one rake face of the cutting tool; and generating with a laser beam at least in areas within the defined contour at least one structure composed of lines; wherein the lines forming the at least one structure are oriented with respect to a profile of at least one cutting edge of the at least one rake face.

2. The method of claim 1, wherein the lines have a mutual spacing of at most 400 m.

3. The method of claim 1, further comprising measuring the profile of the at least one cutting edge optically.

4. The method of claim 1, further comprising measuring a profile of a curvature of the at least one rake face, and considering the curvature when generating the lines.

5. The method of claim 1, further comprising generating the lines with a predetermined distance from the at least one cutting edge.

6. The method of claim 1, further comprising orienting the lines forming the at least one structure with a predetermined angle about a predetermined pivot point.

7. The method according of claim 1, wherein the lines are discontinuous and comprise breaks having a predetermined length.

8. The method of claim 7, wherein the breaks between at least two lines are generated with a predetermined offset.

9. The method of claim 1, wherein the lines have a wavy shape.

10. The method of claim 1, wherein the lines have a depth of between 5 m and 50 m.

11. The method of claim 1, wherein the at least one cutting edge comprises a main cutting edge or a secondary cutting edge, or both, and the contour is delimited by the main cutting edge or the secondary cutting edge.

12. The method of claim 1, wherein starting points of the lines forming the at least one structure are oriented commensurate with the course of the profile of the at least one cutting edge.

13. The method of claim 1, further comprising generating with the laser beam on the at least one rake face within a further contour at least one further structure composed of lines, and orienting the lines forming the further structure with respect to the contour of the existing structure or the orientation of the lines of an existing structure.

14. The method of claim 13, wherein the lines of the at least one further structure have a maximum linewidth of 100 m and a maximum mutual spacing of 400 m.

15. The method according to claim 13, wherein the lines forming the at least one further structure are oriented such that the lines of the existing structure and the lines of the at least one further structure define a wedge shape.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0026] Further details, features and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments illustrated in the drawings, which show in:

[0027] FIG. 1: a schematic diagram for explaining the method according to the invention;

[0028] FIG. 2: a diagram of a drilling tool with a structure generated on a rake face in accordance with method according to the invention;

[0029] FIG. 3: a diagram of a drilling tool with another structure generated on a rake face in accordance with method according to the invention; and

[0030] FIG. 4: an overview of rake faces with different structures produced with the method according to the invention as well as respective shapes of chips obtained during material processing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

[0032] FIG. 1 shows a schematic diagram describing the method according to the invention for the laser-based generation of a structure on a rake face 2 of a cutting tool. With the method according to the invention, a structure with lines 3 is formed, wherein the lines 3 with a maximum mutual spacing of 100 m are generated with a laser beam at least in areas within a predetermined contour 4 on the rake face 2, wherein an orientation or a course of the lines 3 forming the structure is oriented with respect to the profile of a cutting edge, which in the illustrated example has a main cutting edge 1.1 and a secondary cutting edge 1.2. In the illustrated example, the contour 4 is modeled after the profile of the cutting edges 1.1, 1.2. The reference numerals 3.1 to 3.4 refer to variants of orientations of the lines 3 forming the structure. A structure is here formed in each case by a plurality of lines 3 having one of the illustrated orientation variants. The starting points (enlarged points) of the lines 3 of the orientation variants 3.1, 3.2 and 3.3 to be generated by the laser beam are each oriented with respect to the profile of the secondary cutting edge 1.2. In the orientation variant 3.1, a line length is marked with the variable I. The variable b indicates the distance between two lines, which according to the invention is at most 100 m. The orientation variant 3.2 is a structure in which the lines 3 are formed with a discontinuity or break c. The length of a break c is variable. The orientation variant 3.3 is characterized by a predetermined angle about which the lines 3 are oriented on the profile of the cutting edge. In the orientation variant 3.4, the lines 3 are each oriented in a random orientation at a random angle with a random distance from the secondary cutting edge 1.2. The reference numeral 5 indicates a vertical distance of the contour 4 from the main cutting edge 1.1.

[0033] FIG. 2 shows a diagram of a drilling tool 6 with a structure produced on a rake face 7 by the method according to the invention. The structure is formed with substantially parallel lines having a spacing of 100 m. The lines are oriented parallel to the profile of the cutting edge 8, wherein the first line is formed at a distance of 200 m from the cutting edge 8. The structure depth, i.e. the depth of the lines in the rake face 7, is 20 m. The contour of the structure extends over the entire rake face and is delimited by the secondary cutting edge 9.

[0034] FIG. 3 shows a diagram of a further drilling tool 10 with a further structure produced on a rake face 11 by the method according to the invention with essentially mutually parallel lines oriented perpendicular to the profile of the cutting edge 12. The distance of the starting points of the lines from the cutting edge 12 is 200 m. The distance between the lines is 100 m. The line depth is 20 m. The contour of the structure extends over the rake surface 11 and is delimited by the secondary cutting edge 13.

[0035] FIG. 4 shows an overview of rake faces with different structures produced by the method according to the invention, as well as respective shapes of chips obtained during machining. The rake faces shown in A to E of the first row of the overview at a 100-fold magnification are rake faces of a milling tool for polyamide milling applications. A polished chip surface without any structure is shown in column A. Column B shows a rake surface with a structure in the form of continuous lines, which are oriented at an angle of 135 with respect to the cutting edge. Column C also shows a structure with continuous lines, wherein the lines are oriented perpendicularly (90) to the cutting edge. The illustration in column D shows a structure with discontinuous lines, wherein the breaks between the lines having a uniform offset. The lines are oriented parallel with respect to the profile of the cutting edge. Column E shows a rake surface having a structure formed with discontinuous lines, like the one shown in column D, wherein the lines are oriented perpendicular to the cutting edge.

[0036] It has been found that the cutting forces on the cutting edge can be reduced by up to 25%, the burr formation can be reduced by 25%, and the built-up edge can be reduced when machining metals with cutting tools having a structure on their rake face produced by the method according to the invention. In addition, a reduction in spalling or chipping on the tool has been observed.

[0037] The chip length can be reduced by up to 60% when machining plastic materials with cutting tools having a structure on their rake face produced by the method according to the invention, which favors the formation of short chips. Advantageously, short chips can be removed more easily by suction. Due to the favorable chip breaking behavior on the produced structures, an undesirable formation of malleable chips or spiral chips is avoided.

[0038] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

[0039] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: