METHOD FOR MATERIAL-REMOVING MACHINING OF A COMPONENT FOR A TURBOMACHINE

Abstract

The present invention is directed to a method for the material-removing machining of a component for a turbomachine that includes the steps of i) recording a distance image by contact-free measurement of at least one surface of the component that is to be machined; ii) comparing the distance image to a computer model of the component and determining the sites of the component that are to be machined based on deviations between the distance image and the computer model; iii) generating a tool path for the sites of the component that are to be machined; and iv) material-removing machining of the component on the basis of the tool path by spark erosion, laser drilling, or conventional drilling.

Claims

1. A method for material-removing machining of a component for a turbomachine, comprising the steps of: i) recording of a distance image by contact-free measurement of at least one surface of the component that is to be machined; ii) comparing the distance image to a computer model of the component and determining the sites of the component that are to be machined based on deviations between the distance image and the computer model; iii) generating a tool path for the sites of the component that are to be machined; iv) material-removing machining of the component on the basis of the tool path by spark erosion, laser drilling, or conventional drilling.

2. The method according to claim 1, wherein the component to be machined is a used component and, in the course of an overhaul, is machined in a material-removing manner.

3. The method according to claim 1, wherein the component to be machined was machined prior to step i) in a soldering and/or welding process, by crack welding and/or deposition welding.

4. The method according to claim 1, wherein, a site to be machined is a drilled hole, the position of which is determined in step ii).

5. The method according to claim 4, wherein, in step ii), additionally an orientation of the drilled hole is determined and is incorporated into the tool path.

6. The method according to claim 1, wherein the component to be machined has a plurality of drilled holes, wherein the distance image and the computer model in step ii) are aligned on the basis of the drilled holes.

7. The method according to claim 6, wherein, in step ii), a number, a diameter, and/or a pattern of the drilled holes is taken into account.

8. The method according to claim 6, wherein, in step ii), the computer model is expanded and/or compressed for adaptation to the distance image, wherein the site to be machined in the expanded and/or compressed distance image is determined.

9. The method according to claim 1, wherein the distance image in step i) is recorded using a time of flight-based distance measurement using a laser distance measurement.

10. The method according to claim 1, wherein a measuring unit, with which the distance image is recorded in step i), and a machining tool, with which the component is machined in a material-removing manner in step iv), are moved using the same manipulator.

11. A device for the material-removing machining of a component for a turbomachine, comprising: a measuring unit configured and arranged for the recording of a distance image by contact-free measurement of at least one surface of the component to be machined; a machining tool for the material-removing machining of the component by spark erosion, laser drilling, or conventional drilling; and a computer system configured and arranged for comparison of the distance image to a computer model of the component and to determine sites of the component that are to be machined, based on deviations between the distance image and the computer model, and to generate a tool path for the sites of the component that are to be machined.

12. The device according to claim 11, wherein the computer system is additionally configured and arranged to cause the machining tool to carry out the material-removing machining, and to cause a manipulator to move the machining tool along the tool path.

13. The device according to claim 11, further comprising a portal manipulator for guiding the machining tool.

14. The device according to claim 11, further comprising a rotating or swivel table for clamping of the component to be machined for the measurement and/or material-removing machining.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0028] The invention will be explained in detail below on the basis an exemplary embodiment, whereby the individual features in the scope of the secondary [independent] claims can also be essential to the invention in other combination and, moreover, no distinction is made in detail between the different claim categories.

[0029] Shown in detail are:

[0030] FIG. 1 a turbomachine, namely, an aircraft engine in a schematic axial section;

[0031] FIG. 2a a distance image of a component in schematic illustration;

[0032] FIG. 2b a computer model of the component in schematic illustration;

[0033] FIG. 2c a comparison between the distance image and the computer model in schematic illustration;

[0034] FIG. 3 some method steps in a flowchart;

[0035] FIG. 4 a device for material-removing machining of a component by spark erosion and for carrying out the steps in accordance with FIG. 3 in schematic illustration.

DESCRIPTION OF THE INVENTION

[0036] FIG. 1 shows a turbomachine 1, specifically a turbofan engine, in an axial section. The sectional plane thus includes a longitudinal axis 2, around which the rotors rotate during operation. The turbomachine s is divided functionally into a compressor 1a, a combustion chamber 1b, and a turbine 1c. During operation, air intake is compressed in the compressor 1a and then undergoes combustion with admixed fuel, in particular kerosine, in the downstream combustion chamber 1b. The combustion gas or hot gas that is formed undergoes expansion in the turbine 1c and thereby drives the rotors thereof, with proportional conversion into a rotation of the compressor 1a and a rotation of the fan.

[0037] The present subject is aimed, in particular, at the reinspection of such an engine, that is, an inspection after a certain period of operation. Especially the components that face the hot gas can hereby be of interest, in particular a combustion chamber liner 3, which is shown here only schematically and is also referred to as a combustion liner. Such a component can have a plurality of drilled holes and, in the course of the rework, in particular during welding repairs, some of them can be closed unintentionally. In the case of a liner having around 1,200 drilled holes, typically 100 to 400 drilled holes can become closed unintentionally, whereby different drilled holes are affected from component to component.

[0038] In accordance with the present invention, the closed drilled holes are opened by spark erosion or laser drilling or conventional drilling, whereby, for generation of a tool path, initially a distance image 20 is recorded (compare FIG. 2a for illustration). By use of a laser measuring instrument, a surface 21 of the component 23, that is, in the present case, the combustion liner 3, is measured. In the resulting distance image 20, which, for reasons of clarity, is shown only in a cutout in FIG. 2a, an edge 25 and a plurality of drilled holes 26 can be seen by way of example.

[0039] FIG. 2b shows a computer model 30 of the corresponding cutout, in which likewise the edge 25 and, in particular, the drilled holes 26 can be seen. Insofar as only the respective outlet opening that opens in the surface 21 can be seen in the distance image 20, the computer model 30 includes additionally information on the extension of the drilled holes 26 in the component, that is, information on the orientation thereof.

[0040] FIG. 2c illustrates a comparison 40 between the distance image 20 and the computer model 30. In this step, the computer model 30 is adapted to the distance image 20, whereby the number and the pattern of the drilled holes evident in the distance image 20, that is, the opened drilled holes 26, and, furthermore, also a diameter of a drilled hole 36 are taken into account. Evident from the comparison 40 is a site 46 that is to be machined, with not only the position, but also an orientation 57 being taken into account. A drilled hole is supposed to be there, but, according to the distance image 20, it has been closed (during the preceding rework). The absent drilled hole 56 is then subsequently introduced by spark erosion (see below).

[0041] FIG. 3 summarizes some method steps in a flowchart. After the recording 61 of the distance image, it is compared to the computer model 62. On the basis of this comparison, a tool path 66 is generated 63, along which subsequently the machining tool is moved during material-removing machining 64.

[0042] FIG. 4 shows in schematic illustration a device 70 for material-removing machining of the component 23. It is clamped on a rotary or swivel table 71 and the machining tool 75 with the machining electrode 76 is movably mounted relative to it on a portal manipulator 80. An angle of incidence 77 is hereby adjustable. The subject of the device 70 is, furthermore, a computer system 85, in which, on the one hand, the method steps explained on the basis of FIGS. 2a-c, run. On the other hand, the computer system 85 then also actuates the machining tool 75 and the movement thereof by means of the portal manipulator 80. Illustrated cross-hatched is a measuring unit 90, which, in the present case, is a laser distance measuring instrument 91, which, prior to the material-removing machining, is mounted on the portal manipulator 80 in place of the machining tool 75 (that is, in FIG. 4, it has already been exchanged for the machining tool 75).