Cutting tool with pressure sensor

Abstract

A cutting tool comprising at least one cavity spaced apart from an outer contour of the cutting tool by a wear layer, wherein a thickness of the wear layer corresponds to a wear limit of the cutting tool, wherein the cavity is fluidly connected to a supply line arranged within the cutting tool and configured so as to provide a predetermined pressure in the cavity, wherein a pressure sensor fluidly connected to the supply line indicates a wear of the cutting tool when the thickness of the wear layer is reduced to the extent that a pressure change occurs within the supply line.

Claims

1. A cutting tool comprising at least one cavity spaced apart from an outer contour of the cutting tool by a wear layer, wherein a thickness of the wear layer corresponds to a wear limit of the cutting tool, wherein the cavity is fluidly connected to a supply line arranged within the cutting tool and configured so as to provide a predetermined pressure in the cavity, wherein a pressure sensor fluidly connected to the supply line indicates wear of the cutting tool when the thickness of the wear layer is reduced to the extent that a pressure change occurs within the supply line.

2. The cutting tool according to claim 1, wherein a vacuum is present in the cavity such that the pressure in the supply line rises in case of wear.

3. The cutting tool according to claim 1, wherein there is a positive pressure in the cavity such that the pressure in the supply line drops in case of wear.

4. The cutting tool according to claim 1, wherein the cavity is configured as a channel and/or a porous structure.

5. The cutting tool of claim 4, wherein the cavity is configured as a porous honeycomb-like structure.

6. The cutting tool according to claim 1, wherein the cutting tool comprises at least one cutting edge and a cutting surface, wherein the cavity is associated with the cutting edge and/or the cutting surface.

7. The cutting tool according to claim 5, wherein characterized in that a plurality of cutting edges and a plurality of cavities are provided, wherein at least one cavity is associated with each cutting edge.

8. The cutting tool according to claim 5, wherein a plurality of cutting surfaces and a plurality of cavities are provided, wherein at least one cavity is associated with each cutting surface.

9. The cutting tool according to claim 1, wherein the cutting tool is modularly constructed and comprises a cutting insert, in which the cavity is provided.

10. The cutting tool according to claim 1, wherein the cutting tool is coupled to a tool holder such that the supply line of the cutting tool is fluidly connected to a further supply line of the tool holder.

11. The cutting tool according to claim 9, wherein the pressure sensor is arranged in the tool holder.

12. The cutting tool according to claim 1, wherein the cutting tool can be obtained by a 3D printing method, wherein the method comprises the following steps: a) providing a metal powder, in particular a carbide powder, b) 3D printing a cutting tool comprising at least one cavity using the metal powder and thus forming a cutting tool green compact, and c) sintering the cutting tool green compact to create a 3D-printed cutting tool.

13. A machine tool for operating a cutting tool according to claim 1, wherein the machine tool contains a pressure source for generating a vacuum or positive pressure, wherein the pressure source is fluidly connected to the supply line of the cutting tool and/or the tool holder.

14. The machine tool according to claim 13, wherein a pressure sensor is arranged in the machine tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The invention will be described in further detail below with reference to the accompanying drawings, using exemplary embodiments. The drawings show:

[0057] FIG. 1 in a schematic cross-sectional view, a cutting tool according to the invention having a channel-like cavity;

[0058] FIG. 2 in a schematic cross-sectional view, the cutting tool from FIG. 1 having a honeycomb-like cavity;

[0059] FIG. 3 in a schematic cross-sectional view, the cutting tool from FIG. 1 having a tool holder;

[0060] FIG. 4 in a schematic cross-sectional view, the cutting tool from FIG. 2 having a tool holder;

[0061] FIG. 5 in a schematic cross-sectional view, the cutting tool from FIG. 3 with a different arrangement of the pressure sensor;

[0062] FIG. 6 in a schematic cross-sectional view, the cutting tool from FIG. 4 with a different arrangement of the pressure sensor;

[0063] FIG. 7 in a schematic aerial view, a drill head from FIGS. 1, 3, and 5;

[0064] FIG. 8 in a schematic aerial view, a drill head from FIGS. 2, 4, and 6;

[0065] FIG. 9 in a schematic cross-sectional view, the drill head from FIGS. 1, 3, and 5; and

[0066] FIG. 10 in a schematic cross-sectional view, a modular cutting tool having a honeycomb-like cavity.

DETAILED DESCRIPTION

[0067] FIG. 1 shows a cutting tool 10 for performing rotating cutting operations on a workpiece (not shown).

[0068] The cutting tool described in relation to FIG. 1 and in the following figures is provided by way of example only. Generally, the cutting tool can be any cutting tool known in the prior art, such as a milling machine, cutting plate, or rotary tool.

[0069] In the illustrated embodiment, the cutting tool 10 is of the spiral drill type and has helical grooves arranged along the sides of the drill.

[0070] The cutting tool 10 comprises a drill head 18 configured integrally with a shaft 20.

[0071] The shaft 20 has an elongated shape with two opposing ends, wherein the shaft 20 opens into the drill head 18 with one end and has a coupling portion 38 at the other end.

[0072] The drill head 18 has an outer contour 14 that corresponds to the surface of the drill head 18.

[0073] According to the invention, the drill head 18 comprises a cavity 12.

[0074] The cavity 12 is located in the cutting body 13 of the drill head 18.

[0075] The cavity 12 is spaced apart from the outer contour 14 by a wear layer 16.

[0076] The cavity 12 is configured in a channel-like manner and extends from the tip of the drill head 18 in the direction of its lateral end.

[0077] The channel-like cavity 12 is fluidly connected via two connecting channels 30 to a distribution chamber 28 arranged proximally in the drill head 18.

[0078] The connecting channels 30 extend from the proximally arranged distribution chamber 28 to the distally arranged cavities 12.

[0079] The distribution chamber 28 is fluidly connected to a supply line 24. The supply line 24 extends from the distribution chamber 28 through the shaft 20, wherein the supply line 24 is evenly spaced apart from the outer wall of the shaft 20. The latter subsequently opens into an interface 32 associated with the coupling portion 38.

[0080] The coupling portion 38 further comprises a pressure sensor 34 fluidly connected to the supply line 24. Advantageously, the pressure sensor is associated with the interface 32.

[0081] Particularly preferably, the pressure sensor 34 is a capacitive pressure sensor.

[0082] The coupling portion 38 is configured so as to be coupled to a tool holder. For this purpose, it can be equipped with corresponding grid elements (not shown here) to enable coupling.

[0083] Further, at the coupling portion 38, the supply line 24 is fluidly connected to a pressure source 36.

[0084] The pressure source 36 is configured so as to generate a positive pressure or a vacuum in the supply line 24. Thus, a positive pressure or a vacuum is also present in the cavity 12. The pressure source 36 can in particular be a pump.

[0085] The pressure source 36 is preferably arranged outside of the cutting tool 10.

[0086] The wear on the cutting tool 10 of FIG. 1 will be explained in further detail below.

[0087] In operation, the cutting tool 10 performs rotating cutting operations on a workpiece, thereby causing a wear on the outer contour 14 of the drill head 18. As a result of the wear, the wear layer 16 is removed and the cavity 12 is opened. It is sufficient for the wear layer 16 to be removed in at least one place. Uneven wear therefore also results in the cavity 12 being opened in at least one place. As a result, there is a pressure change in the cavity 12 and thus in the supply line 24. This change in pressure can be measured by the pressure sensor 34, whereupon it generates a signal and passes it to an operator. The operator receives the information that the wear limit of the cutting tool 10 has been reached. Operation can be suspended and the cutting tool 10 can be replaced. A time-consuming and cost-intensive monitoring under a microscope can thus be avoided.

[0088] FIG. 2 shows the cutting tool 10 of FIG. 1, with the difference that the cavity 12 is honeycomb-like.

[0089] With respect to the other features and parts, the same statements apply as those already made in relation to FIG. 1.

[0090] FIG. 3 shows the cutting tool 10 of FIG. 1 with a tool holder 26. Otherwise, FIG. 3 contains the same components as already described in relation to FIG. 1.

[0091] The tool holder 26 is connected between the interface 32 and the pressure source 36 from FIG. 1. The two are fluidly connected to one another by a further supply line 24 arranged in the tool holder 26.

[0092] The tool holder 26 is latched to the coupling portion 38 of the shaft 20 such that a gas-tight supply line 24 is formed, which opens from the distribution chamber 28 through the shaft 20 into the tool holder 26. The supply line 24 in the tool holder 26 is connected to the pressure source 36 via an interface 32.

[0093] FIG. 4 shows the cutting tool of FIG. 3 with the difference that the cavity 12 forms a porous honeycomb-like structure. Otherwise, FIG. 4 contains the same components as already described in relation to FIG. 3.

[0094] FIG. 5 shows the cutting tool 10 of FIG. 3, with the difference that the pressure sensor 34 is arranged outside of the cutting tool 10.

[0095] The pressure sensor 34 can be associated with the pressure source 36.

[0096] In particular, the pressure sensor 34 can be accommodated together with the pressure source 36 in a machine that drives the cutting tool 10.

[0097] FIG. 6 shows the cutting tool of FIG. 4, with the difference that the pressure sensor 34 is arranged outside the cutting tool 10, as already explained in relation to FIG. 5. Otherwise, FIG. 6 contains the same components as already described in relation to FIG. 4.

[0098] FIG. 7 shows an aerial view of a drill head 18 from FIGS. 1, 3, and 5.

[0099] As can be readily seen in FIG. 7, the channel-like cavity 12 is spaced apart from the outer contour 14 of the drill head 18 by a wear layer 16. The wear layer 16 has a thickness d. The thickness d of the wear layer 16 corresponds to a wear limit of the cutting tool 10.

[0100] FIG. 8 shows an aerial view of the drill head 18 of FIGS. 2, 4, and 6. The thickness d shown in FIG. 8 also corresponds to the thickness of the wear layer 16.

[0101] FIG. 9 shows an enlarged view of the drill head 18 from FIGS. 1, 3, and 5. Moreover, the cutting tool 10 of FIG. 9 contains the same components and features as already described in relation to FIGS. 1, 3, and 5.

[0102] As can be readily seen in FIG. 9, the channel-like cavity 12 is spaced apart from the outer contour 14 of the cutting tool 10, in particular the drill head 18, by a wear layer 16 having the thickness d.

[0103] The wear layer 16 corresponds in particular to a wear limit of the cutting tool 10. In other words, if the wear layer is selected larger, then the wear of the cutting tool 10 is indicated only after a longer period of operation. Conversely, if the wear layer 16 is reduced, the operating time after which wear is indicated is also reduced.

[0104] FIG. 10 shows a modular cutting tool 22.

[0105] The modular cutting tool 22 comprises a disposable drill head 18 attached to and engaged with the shaft 20.

[0106] Moreover, the modular cutting tool 22 contains the same components as already described in relation to FIG. 2. In this respect, reference is made to the descriptions for FIG. 2.

LIST OF REFERENCE NUMERALS

[0107] 10 Cutting tool [0108] 12 Cavity [0109] 13 Cutting body [0110] 14 Outer contour [0111] 16 Wear layer [0112] 18 Drill head [0113] 20 Shaft [0114] 22 Modular cutting tool [0115] 24 Supply line [0116] 26 Tool holder [0117] 28 Distribution chamber [0118] 30 Connecting channel [0119] 32 Interface [0120] 34 Pressure sensor [0121] 36 Pressure source [0122] 38 Coupling portion [0123] d Thickness of the wear layer