METHOD AND ARRANGEMENT FOR MACHINING A WORKPIECE

Abstract

The invention relates to a method and an arrangement for machining a workpiece with a surface, into which a groove structure with grooves and interposed ribs is introduced, wherein undesirable burrs can develop on the groove structure. According to the invention, for testing and determining the formation of burrs a measuring means is provided which emits a light to the surface of the groove structure and receives light reflected from the surface, wherein a degree of the burr formation is determined depending on the reflected light.

Claims

1. Method for machining a workpiece with a surface, in particular in a bore, into which a groove structure with grooves and interposed ribs is introduced, wherein undesirable burrs can develop on the groove structure, characterized in that for testing and determining a formation of burrs a measuring means is provided which emits a light to the surface of the groove structure and receives light reflected from the surface, wherein a degree of the burr formation is determined depending on the reflected light.

2. Method according to claim 1, characterized in that by means of the measuring means the determination of the burr formation is carried out simultaneously or immediately after the introduction of the groove structure.

3. Method according to claim 1, characterized in that the light is chromatic.

4. Method according to claim 1, characterized in that the measuring means has at least one confocal point sensor which emits and receives the light.

5. Method according to claim 1, characterized in that a reduction of a ratio between reflected light and emitted light is considered as a degree of an increase in the burr formation.

6. Method according to claim 1, characterized in that the groove structure is introduced with a material removing tool, in particular a cutting head or a rotary chisel.

7. Method according to claim 6, characterized in that on reaching a predetermined value for the reflected light the material removing tool is readjusted and/or exchanged.

8. Method according to claim 1, characterized in that after the introduction and testing of the groove structure a coating is applied thereto.

9. Arrangement for machining a workpiece, in particular pursuant to a method according to claim 1, with a material removal device for introducing a groove structure with grooves and interposed ribs into a surface of the workpiece, characterized in that for testing and determining a formation of burrs on the groove structure a measuring means is provided which is designed to emit a light to the surface of the groove structure and receive light reflected from the surface, wherein a degree of the burr formation can be determined depending on the reflected light.

10. Arrangement according to claim 9, characterized in that the measuring means is arranged on the material removal device.

11. Arrangement according to claim 9, characterized in that the groove structure is introduced into the workpiece with at least one material removing tool and in that a display is provided which, depending on a measurement result of the measuring means, displays when the at least one material removing tool is to be changed.

12. Arrangement according to claim 1, characterized in that the measuring means has at least one confocal point sensor which emits and receives the light.

Description

[0026] The invention is explained further hereinafter by way of a preferred exemplary embodiment illustrated schematically in the drawing.

[0027] The single FIGURE shows in a highly schematic manner an enlarged partial cross-sectional view of a workpiece 10, into a surface of which a groove structure 12 with ribs 16 that are dovetail-like in cross-section and interposed grooves 14 is introduced in a chip-removing manner. The groove structure 12 is illustrated in a greatly enlarged manner, whereas in a real workpiece 10 this can be a macroscopic groove structure with a groove depth of a few millimeters or less than one millimeter. The schematically indicated workpiece 10 can in particular be an engine block with a cylinder bore, into the bore wall of which the groove structure 12 is introduced.

[0028] By means of a measuring means 20, of which a confocal point sensor 22 is illustrated in a highly schematic manner, a light 24 is emitted substantially vertically onto the surface of the groove structure 12, in particular onto an upper side of the ribs 16. The light 24 is reflected on the surface of the groove structure 12 and can be returned as reflected light 26 into the confocal point sensor 22 of the measuring means 20. In this regard, the smoother the surface of the groove structure 12 is, the higher the proportion of reflected light 26 that is returned into the confocal point sensor 22.

[0029] As illustrated graphically on the right side of the drawing, during material removing introduction of the groove structure 12 into the surface of the workpiece 10 undesirable burrs 18 can especially arise on the ribs 16 of the groove structure 12 depending, in particular, on the state of the machining tools but also depending on the material of the respective workpiece 10.

[0030] If the point sensor 22 of the measuring means 20 is moved over the surface region with a burr 18, unlike a smooth surface a part of the emitted light 24 is radiated on flanks of the burr 18 as laterally reflected light 26b. Consequently, this can no longer be received and captured by the confocal point sensor 22 of the measuring means 20. Only a part of the vertically reflected light 26a is returned into the point sensor 22.

[0031] Together with a non-depicted control means or a computer unit the measuring means 20 is in each case designed, depending on a ratio between the emitted light 24 and the proportion of the reflected light 26 which is returned into the point sensor 22, to make an statement as to the degree, in particular the number and/or size, of burrs 18 on the groove structure 12 of the workpiece 10. Depending on the measurement result a signal indicating, for example, a necessary change of the machining tool in the previous machining step of introducing the groove structure 12, can then be issued or such a change is brought about automatically.

[0032] Subsequent to the measurement a surface coating of the surface of the workpiece 10 with the groove structure 12 can take place. In particular, this can be implemented by spraying on melted metal particles using sufficiently known spraying methods.