Abstract
A tool blank (30) for a cutting tool (1), such as an end mill, drill or engraving tool, includes a tool shank (2) configured to be received in a rotating tool holder of a processing machine, and a cutting head blank (3) fixedly connected to the tool shank (2). The cutting head blank (3) includes multiple cutting head blank elements (5) fixedly connected to each other, preferably soldered to each other, and made of a high hardness material such as polycrystalline diamond. A cutting tool (1), such as an end mill, drill or engraving tool, has at least one tool cutting edge (15) that is defined on such a tool blank (30) and extends over multiple cutting head blank elements (5) that are fixedly connected to one another.
Claims
1. A tool blank for a cutting tool, including: a tool shank configured to be received in a rotating tool holder of a processing machine, and a cutting head blank fixedly connected to the tool shank, the cutting head blank comprising multiple cutting head blank elements that are fixedly connected to one another, and are made of a high-hardness material having a hardness (HV) in the range of 2000-10000 kg/mm.sup.2.
2. The tool blank according to claim 1, wherein the multiple cutting head blank elements are stacked on each other in multiple stacked columns that extend in parallel in the direction of an axis of rotation (R) of the tool blank and are disposed around the axis of rotation (R).
3. The tool blank according to claim 2, wherein a first one of the cutting head blank elements in one a first one of the multiple stacked columns is disposed in an offset manner with respect to an adjacent second one of the cutting head blank elements in a second one of the multiple stacked columns with an offset in the direction of the axis of rotation (R).
4. The tool blank according to claim 3, wherein the offset V is in the range of 20% to 80% of a height (x1), which is measured in the direction of the axis of rotation, of the first one of the cutting head blank elements or of the second one of the cutting head blank elements.
5. The tool blank according to claim 2, wherein a third one of the cutting head blank elements in a first one of the multiple stacked columns is disposed at a rotational offset angle () about the axis of rotation (R) with respect to an adjacent fourth one of cutting head blank elements of the first stacked column.
6. The tool blank according to claim 5, wherein the rotational offset angle () is in the range of 10 to 80.
7. The tool blank according to claim 1 having two stacked columns, wherein the cutting head blank elements each have a semi-cylindrical shape and are disposed such that the cutting head blank has a cylindrical shape.
8. The tool blank according to claim 1, wherein; the multiple cutting head blank elements are disposed in a single stacked column and have a cylindrical shape, and adjacent ones of the cutting head blank elements of the single stacked column abut against each other at respective abutment surfaces and are connected to each other at these abutment surfaces.
9. The tool blank according to claim 1, wherein at least one abutment surface between two of the cutting head blank elements, which abut on each other in the direction of an axis of rotation (R) of the tool blank, has an angle of inclination () with respect to the axis of rotation (R) in the range of 75-89 in at least regionally region of the tool blank.
10. The tool blank according to claim 1, further comprising a pin projecting from an end face of the tool shank to which the cutting head blank is attached, wherein a bore or recess is formed in at least one of the cutting head blank elements such that the at least one of the cutting head blank elements having the bore or recess is attached to the pin of the tool shank in a form-fit manner.
11. The tool blank according to claim 1, wherein: the cutting head blank elements each have a height (x1), which is measured in the direction of an axis of rotation of the tool blank, in the range from 0.2 mm to 2 mm, in particular in the range from about 0.5 mm to 1.5 mm, and the cutting head blank has a length (x2), which is measured in the direction of the axis of rotation, in the range from 0.2 mm to 15 mm, in particular in the range from about 2 mm to 10 mm.
12. A cutting tool, wherein at least one tool cutting edge, which extends across a plurality of the fixedly interconnected cutting head blank elements, have been machined on the tool blank according to claim 1.
13. The cutting tool according to claim 12, wherein the at least one tool cutting edge does not contact an abutment surface between cutting head blank elements of different stacked columns.
14. A method for manufacturing a cutting head blank for a cutting tool including: providing multiple prefabricated cutting head blank elements made of a high-hardness material, fixedly connecting the multiple cutting head blank elements to each other and to a tool shank such that the interconnected cutting head blank elements form a cutting head blank that is fixedly connected to the tool shank.
15. The method according to claim 14, wherein the step of fixedly connecting the multiple cutting head blank elements to each other and to the tool shank is performed by first connecting the cutting head blank elements to form the cutting head blank and then connecting the cutting head blank to the tool shank.
16. The method according to claim 14, wherein the step of fixedly connecting the multiple cutting head blank elements to each other and to the tool shank is performed by piece by piece connecting individual ones of the cutting head blank elements to the tool shank or to a cutting head blank element that is already connected to the tool shank.
17. A method for manufacturing a cutting tool, including: providing the cutting head blank according to claim 14, and machining at least one tool cutting edge on the cutting head blank such that the at least one cutting edge extends across multiple ones of the cutting head blank elements.
18. The tool blank according to claim 1, wherein the multiple cutting head blank elements are fixedly connected to one another by solder.
19. The tool blank according to claim 1, wherein the high-hardness material is polycrystalline diamond.
20. The method according to claim 14, wherein the multiple prefabricated cutting head blank elements are polycrystalline diamond blanks.
21. The method according to claim 17, wherein the cutting tool is an end mill, drill or engraving tool.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] Exemplary embodiments of the present teachings are described and explained in more detail below with reference to the accompanying drawings.
[0063] FIG. 1 shows a side view of a cutting tool according to the present teachings.
[0064] FIG. 2 shows a sectional view of the cutting tool 1 shown in FIG. 1 along section A-A shown in FIG. 1.
[0065] FIG. 3 shows a front view of a tool blank according to the present teachings in accordance with a first embodiment.
[0066] FIG. 4 shows a sectional view of the tool blank shown in FIG. 3 along section B-B shown in FIG. 3.
[0067] FIG. 5 shows a sectional view of the tool blank shown in FIGS. 3 and 4 along section C-C shown in FIG. 4.
[0068] FIG. 6 shows a schematic view of the four tool cutting edges depicted in FIG. 5 in unrolled form and plotted one below the other.
[0069] FIG. 7 shows a perspective view from diagonally in front of the tool blank shown in FIGS. 3 to 5.
[0070] FIG. 8 shows a front view of a tool blank according to the present teachings in accordance with a second embodiment.
[0071] FIG. 9 shows a sectional view of the tool blank shown in FIG. 8 along section D-D shown in FIG. 8.
[0072] FIG. 10 shows two sectional views of the tool blank shown in FIG. 9 along sections E-E and F-F shown in FIG. 9.
[0073] FIG. 11 shows a sectional view of a cutting tool according to the present teachings perpendicular to the axis of rotation R.
[0074] FIG. 12 shows a sectional view of a tool blank according to the present teachings according to a fourth embodiment.
[0075] FIG. 13 shows a sectional view of a tool blank according to the present teachings according to a fifth embodiment.
[0076] FIG. 14 shows a sectional view of a tool blank according to the present teachings in accordance with a sixth embodiment.
[0077] FIG. 15 shows a sectional view of a tool blank according to the present teachings according to a seventh embodiment.
[0078] FIG. 16 shows a sectional view of the tool blank shown in FIG. 15 along section G-G shown in FIG. 14.
[0079] FIG. 17 is a sectional view of a tool blank according to the present teachings in accordance with an eighth embodiment.
DETAILED DESCRIPTION
[0080] FIG. 1 shows a side view of a cutting tool 1 according to the present teachings in accordance with a first embodiment. A cutting head 6 is connected to a tool shank 2 at a shank joint 11. In use, the cutting tool 1 rotates about the axis of rotation R. The cutting head 6 is manufactured by producing (e.g., machining, cutting) tool cutting edges 15 on a cutting head blank 3. The cutting head blank 3 as such is thus no longer visible in FIG. 1. In other words, a cutting head blank 3 that has already been further processed into a cutting head 6 is shown in FIG. 1. The cutting head blank 3 is formed by a plurality of cutting head blank elements 5 that are stacked on each other. The cutting head blank elements 5 are stacked on each other in a stack-like structure. Adjacent cutting head blank elements 5 abut against each other at respective abutment surfaces 7. The cutting head blank elements 5 are no longer visible as such in FIG. 1. Cutting head blank elements 5 that have already been further processed are shown. In this disclosure, the term cutting head blank element is also used for the cutting head blank elements having a tool cutting edge that has been produced thereon.
[0081] Cutting head blank elements 5a, 5c, 5d are shown in an exemplary manner for the cutting head blank elements 5; in addition, abutment surfaces 7b, 7c, 7d are shown in an exemplary manner for the abutment surfaces 7. The cutting head blank element 5a abuts against the cutting head blank element 5c at the abutment surface 7b. Furthermore, the cutting head blank element 5a abuts against the cutting head blank element 5d at the abutment surface 7c. The cutting head blank elements 5c and 5d abut against each other at the abutment surface 7d.
[0082] Multiple tool cutting edges 15 extend across a plurality of the cutting head blank elements 5.
[0083] The multiple cutting head blank elements 5, which are fixedly connected to each other, are disposed in the direction of and around the axis of rotation R.
[0084] The abutment surfaces 7b, 7c are not perpendicular to the axis of rotation R, but rather are inclined at an angle with respect to the axis of rotation R.
[0085] FIG. 2 shows a sectional view of the cutting tool 1 shown in FIG. 1 along section A-A. The section plane extends through the abutment surfaces 7b and 7c. The section plane is thus disposed at the angle with respect to the axis of rotation R. The abutment surfaces 7b, 7c abut against each other at the abutment surface 7a and are connected to each other there. Two tool cutting edges 15 are produced both on the outer circumference of the cutting head blank element 5a and on the outer circumference of the cutting head blank element 5b.
[0086] FIG. 3 shows a front view of a tool blank 30 according to the present teachings in accordance with a first embodiment.
[0087] No tool cutting edges 15 have yet been produced on the cutting head blank 3 shown in FIG. 3. A pin 9 is disposed on the tool shank 2. Two cutting head blank elements 5e, 5f are disposed one above the other on the pin 9. The cutting head blank elements 5e, 5f abut at the abutment surfaces 7e and 7f and are connected together. In addition, the cutting head blank elements 5e, 5f are connected to the pin 9 of the tool shank 2 at the shank joint 11.
[0088] FIG. 4 is a sectional view of the tool blank 30 shown in FIG. 3 along the section B-B shown in FIG. 3. A total of seven cutting head blank elements 5e, 5f, 5g, 5h, 5i, 5j, 5k are disposed on the pin 9 of the tool shank 2. The two cutting head blank elements 5e, 5f that are disposed on the right side of the pin 9 are the cutting head blank elements 5e, 5f shown in FIG. 3.
[0089] The cutting head blank elements 5e, 5f, 5g, 5h, 5i, 5j, 5k abut on each other at the abutment surfaces 7g, 7h, 7i, 7j, 7k and are connected to each other there. The cutting head blank elements 5e, 5f, 5g, 5h, 5i, 5j, 5k are connected to the tool shank 2 or the pin 9 of the tool shank 2 at the shank joint 11. The cutting head blank elements 5e, 5i, 5j, 5k are stacked on each other in a first stacked column 12a in the direction of the axis of rotation R, and the cutting head blank elements 5f, 5g, 5h are stacked on each other in a second stacked column 12b in the direction of the axis of rotation R. The first stacked column 12a and the second stacked column 12b are disposed one above the other. The first stacked column 12a and the second stacked column 12b extend parallel to each other.
[0090] The cutting head blank elements 5e, 5i, 5j, 5k of the first stacked column 12a and the cutting head blank elements 5f, 5g, 5h of the second stacked column 12b are disposed in an offset manner from each other in the direction of the axis of rotation R. Accordingly, there is an offset V in the direction of the axis of rotation R between the abutment surfaces 7g, 7h, 7i of the first stacked column 12a and the abutment surfaces 7j, 7k of the second stacked column 12b. For example, the offset V between the abutment surfaces 7j and 7h is shown in FIG. 4.
[0091] FIG. 5 is a sectional view of the tool blank 30 shown in FIGS. 3 and 4 along the section C-C shown in FIG. 4. The cutting head blank element 5g having the shank joint 11 is attached to the pin 9 from below. On the upper half of the pin 9, the section extends exactly through the abutment surface 7h between the cutting head blank elements 5j and 5k. Thus, an end face of the cutting head blank element 5j is shown. The cutting head blank elements 5j and 5g abut against each other at the abutment surfaces 71, 7m and are connected with each other there. Furthermore, four tool cutting edges 15c-15f are illustrated. The depiction of the tool cutting edges 15c-15f corresponds to a front view onto the tool blank and not to the sectional view along section C-C. The tool cutting edges 15c-15f are illustrated in FIG. 5 merely as an example. In FIGS. 3, 4 and 7, which also show the first embodiment, the tool cutting edges 15c-15f are not illustrated.
[0092] FIG. 6 shows a schematic view of the four tool cutting edges 15 shown in FIG. 5. The four tool cutting edges 15c-15f, which are disposed around the axis of rotation R of the cutting head blank, are shown in FIG. 6 in unrolled form from left to right and are plotted one above the other. The tool cutting lengths Ls shown in FIG. 6 are respectively the lengths of the tool cutting edges 15c-15f from the end of the cutting head 6 that is connected to the tool shank 2 to the terminal end of the cutting head 6. The tool cutting lengths Ls of the four tool cutting edges 15c-15f are equally long.
[0093] Furthermore, FIG. 6. shows, for each of the four tool cutting edges 15c-15f, which are depicted in unrolled form, at (along) which length of the tool cutting edges 15c-15f an abutment surface 7 is located, i.e. at (along) which points/lengths the tool cutting edges extend over from one cutting head blank element 5 to another cutting head blank element 5. The abutment surfaces 7 of the tool cutting edges 15c and 15e are located at equal lengths. The abutment surfaces 7 of the tool cutting edges 15d and 15f are located at equal lengths. But the abutment surfaces 7 of the tool cutting edges 15c and 15e are located at different lengths along the tool cutting edge as compared to the tool cutting edges 15d and 15f. Accordingly, the abutment surfaces 7 of the tool cutting edges 15c and 15e are disposed in an offset manner from the abutment surfaces 7 of the tool cutting edges 15d and 15f.
[0094] FIG. 7 is a perspective view from obliquely in front of the tool blank 30 shown in FIGS. 3 to 5. The cutting head blank elements 5e, 5i, 5j, 5k extend in the first stacked column 12a in the direction of the axis of rotation R and parallel to a second stacked column 12b that is formed by the cutting head blank elements 5f, 5g, 5h. The cutting head blank elements 5e, 5f, 5g, 5h, 5i, 5j, 5k are stacked on each other in a stacking structure. They abut against each other at abutment surfaces 7, of which abutment surfaces 7g, 7h, 7j are shown in an exemplary manner. Furthermore, abutment surfaces of cutting head blank elements abutting each other in a direction perpendicular to the axis of rotation R are shown in an exemplary manner as abutment surfaces 7e, 7f.
[0095] Because the cutting head blank elements 5e, 5f, 5g, 5h, 5i, 5j, 5k are disposed offset to each other in the direction of the axis of rotation R, for example, the abutment surface 7j does not directly border the abutment surfaces 7g or 7h.
[0096] FIG. 8 shows a front view of a tool blank 30 according to the present teachings in accordance with a second embodiment.
[0097] A pin 9 is attached to the tool shank 2. Two cutting head blank elements 5l, 5m are disposed on the pin 9 one above the other. The cutting head blank elements 5l, 5m abut together at the abutment surfaces 7n and 7o and are connected together there. Moreover, the cutting head blank elements 5l, 5m are connected to the pin 9 of the tool shank 2 at the shank joint 11.
[0098] FIG. 9 is a sectional view of the tool blank 30 shown in FIG. 8 along the section D-D shown in FIG. 8. The pin 9 of the tool shank 2 extends in the direction of the axis of rotation R and in a bore 8 that passes through six cutting head blank elements 5l, 5m, 5n, 5o, 5p, 5q. The cutting head blank elements 5l, 5m, 5n, 5o, 5p, 5q abut against each other at abutment surfaces 7, of which abutment surfaces 7p, 7q are shown in an exemplary manner in FIG. 9. At the shank joint 11, the cutting head blank elements 5l, 5m, 5n, 5o, 5p, 5q are connected to the tool shank 2 or to the pin 9 of the tool shank 2. The cutting head blank elements 5l, 5m, 5n, 5o, 5p, 5q are disposed in the direction of the axis of rotation R without an offset V.
[0099] FIG. 10 shows two sectional views of the tool blank 30 shown in FIG. 9 along sections E-E and F-F shown in FIG. 9. Section E-E shows end faces of cutting head blank elements 5o, 5p. Section F-F shows end faces of cutting head blank elements 5n, 5q.
[0100] In the section E-E shown on the left, the abutment surfaces 7r and 7s between the two cutting head blank elements 5o and 5p can be seen. Further, the abutment surfaces 7t and 7u between the two cutting head blank elements 5n and 5q are shown in dashed line, as shown in the section F-F shown on the right. Conversely, the abutment surfaces 7r and 7s, which are depicted in the section E-E, are shown in dashed line in the section F-F shown on the right. The abutment surfaces 7r and 7s are disposed at a rotational offset angle with respect to the abutment surfaces 7t and 7u.
[0101] FIG. 11 is a sectional view of another exemplary embodiment of a cutting tool perpendicular to the axis of rotation R. Two cutting head blank elements 5 are connected to each other at two abutment surfaces 7v, 7w. Furthermore, the cutting head blank elements 5 are connected to the pin 9 of the tool shank 2 at the pin joint 11. Two tool cutting edges 15 are disposed on the outer circumference of each of the cutting head blank elements 5, of which the tool cutting edges 15a and 15b are shown in an exemplary manner. The abutment surface 7v extends between the tool cutting edges 15a and 15b. In addition, an area B is shown that lies between the tool cutting edges 15a and 15b and is spaced apart from the tool cutting edges 15a and 15b. This area identifies an area in which the abutment surface 7v is disposed. The same applies to the areas lying between the other tool cutting edges, which are not indicated in FIG. 11. Accordingly, the joints in these areas are also disposed at a distance (spaced apart) from the tool cutting edges.
[0102] FIG. 12 to FIG. 17 show further exemplary embodiments of tool blanks according to the present teachings.
[0103] FIG. 12 shows the sectional view of an exemplary fourth embodiment. In FIG. 12, the cutting head blank 3 is formed by the stack structure of three cutting head blank elements 5. The cutting head blank elements 5 have a height (length) x1 that is measured in the direction of the axis of rotation R. The cutting head blank 3 has a length (height) x2 that is measured in the direction of the axis of rotation R.
[0104] FIG. 13 shows the sectional view of an exemplary fifth embodiment. In FIG. 13, the cutting head blank 3 is formed by the stacked structure of ten cutting head blank elements 5. Nine cutting head blank elements 5 are attached from above and below, respectively, to the pin 9 of the tool shank 2, and the abutment surfaces (joints) 7 of these nine cutting head blank elements 5 have an offset V in the direction of the axis of rotation R. On the far right, a cutting head blank element 5 is additionally attached as an ending to the end face of the pin 9. Such an embodiment is suitable, in particular, for end-cutting and forming tools.
[0105] FIG. 14 shows the sectional view of an exemplary sixth embodiment. In FIG. 14, the cutting head blank 3 is formed by the stack structure of six cutting head blank elements 5. The abutment surfaces 7 between the cutting head blank elements 5 are not perpendicular to the axis of rotation R, but rather are disposed inclined at an angle with respect to the axis of rotation R.
[0106] FIG. 15 shows the sectional view of an exemplary seventh embodiment having five cutting head blank elements 5 disposed on a pin 9. The abutment surface 7x between the cutting head blank elements 5r and 5s is not at a right angle to the axis of rotation R.
[0107] FIG. 16 shows a sectional view of the tool blank shown in FIG. 15 along section G-G shown in FIG. 15.
[0108] FIG. 17 is a sectional view of a tool blank according to the present teachings in accordance with an eighth embodiment. In FIG. 17, the cutting head blank 3 is formed by the stack structure of six cutting head blank elements 5. The abutment surfaces 7 between the cutting head blank elements 5 are not at right angles to the axis of rotation R, but rather are disposed at an angle oblique with respect to the axis of rotation. In contrast to the embodiment shown in FIG. 14, the abutment surface is additionally angled such that it extends outwardly symmetrically with respect to the axis of rotation R as seen in sectional view from the axis of rotation R. The abutment surface 7 thus forms a tip in the region of the axis of rotation R, which is form-fit connected with an oppositely-shaped recess of the adjacent cutting head blank element 5.
[0109] In addition, as shown in FIG. 15, a pin and a bore can be provided in the cutting head blank elements 5. Such a pin and bore are not shown in FIG. 17.
INDUSTRIAL APPLICABILITY
[0110] Cutting tools according to the present teachings make it possible to produce from small cutting head blank elements a proportionally larger cutting head blank or a larger cutting head having a long tool cutting edge. Such a large cutting tool is not subject to the disproportionate cost increase with volume as it is known, for example, with PCD blanks. For this reason, cutting tools having high wear resistance, great process reliability and long tool life, as well as cutting tools having large cutting heads, can be fabricated at lower cost using the present teachings.
[0111] Referring now to FIG. 7 and FIG. 1, an exemplary manufacturing process for a cutting tool is described in detail as follows.
[0112] The cutting head blank elements 5 are attached one after the other to the pin 9 of the tool shank 2 shown in FIG. 7. For this purpose, for example, the cutting head blank element 5i is first attached to the pin 9 such that it is connected to the tool shank 2 at the shank joint 11. The shank joint 11 here refers both to the connection with the section of the tool shank 2 that extends perpendicular to the axis of rotation and to the connection with the pin 9. One after another, the other cutting head blank elements 5 are attached to the pin 9. The cutting head blank elements 5 are connected to each other at the abutment surfaces 7, for example, by a solder connection. In this way, a cutting head blank 3 is created as shown in FIG. 7. The cutting head blank is composed of a total of seven cutting head blank elements 5. At least one tool cutting edge 15 is then produced (e.g., machined, cut) on this cutting head blank 3. A cutting head 6 is created thereby. For example, a cutting head 6 as depicted in FIG. 1 results. The tool cutting edges 15 extend over a plurality of the cutting head blank elements 5.
List Of Reference Signs
[0113] 1 Cutting tool [0114] 2 Tool shank [0115] 3 Cutting head blank [0116] 5, 5a-5q Cutting head blank element [0117] 6 Cutting head [0118] 7, 7a-7u Abutment surface [0119] 8 Bore, through hole [0120] 9 Pin [0121] 11 Shank joint [0122] 12, 12a, 12b Stacked column [0123] 15 Tool cutting edge [0124] 30 Tool blank [0125] R Axis of rotation [0126] A Angle of inclination [0127] Rotational offset angle [0128] V Offset [0129] x1 Height of the cutting head blank [0130] x2 Length of the cutting head [0131] L1 Element-cylinder height, element-half-cylinder height [0132] L2 Blank-cylinder height
