DE102021104447A1 - Process for repairing a surface defect in a workpiece - Google Patents

Abstract

Method for repairing a surface defect (1, 8) of a workpiece (2), which consists at least partially of brass, copper or a copper alloy, comprising at least the following steps: a) measuring the surface defect (1, 8) with a 3D scanner for production of repair data; andb) repairing the surface defect (1, 8) with a 3D printer depending on the repair data.

Description

The present invention relates to a method for repairing a surface defect in a workpiece which consists at least partially of brass, copper or a copper alloy.

Workpieces cast from brass, copper or a copper alloy may have surface defects such as cracks, pores and/or defects after casting. Workpieces damaged in this way therefore often have to be scrapped. This can lead to high costs, particularly in the case of workpieces that are manufactured in a very complex manner. Attempts have therefore already been made to repair surface defects in such workpieces by brazing. However, it has been found that a connection between the workpiece and the solder is not strong enough. In addition, brazing requires a subsequent etching process to remove residues. Ordinary welding of workpieces made of brass, copper or a copper alloy is also not possible.

Proceeding from this, it is the object of the present invention to at least partially solve the problems described with reference to the prior art. In particular, a method is to be specified with which a surface defect in a workpiece that consists at least partially of brass, copper or a copper alloy can be repaired in a cost-effective manner.

This object is solved by the features of the independent patent claim. Further advantageous refinements of the invention are specified in the dependent patent claims. It should be pointed out that the features listed individually in the dependent patent claims can be combined with one another in any technologically meaningful way and define further refinements of the invention. In addition, the features specified in the patent claims are specified and explained in more detail in the description, with further preferred configurations of the invention being presented.

1. a) Vermessen des Oberflächenfehlers mit einem 3D Scanner zur Erzeugung von Reparaturdaten; und
2. b) Reparieren des Oberflächenfehlers mit einem 3D Drucker in Abhängigkeit von den Reparaturdaten.

A method for repairing a surface defect in a workpiece that consists at least partially of brass, copper or a copper alloy, which comprises at least the following steps, contributes to this:

1. a) Measurement of the surface defect with a 3D scanner to generate repair data; and
2. b) Repairing the surface defect with a 3D printer depending on the repair data.

The workpiece can consist at least partially or entirely of brass, copper or a copper alloy. Brass is in particular an alloy that includes copper and zinc. Furthermore, the workpiece can be cast from brass, copper or the copper alloy. In addition, the workpiece can be at least partially printed with a 3D printer. Such workpieces can have surface defects, such as cracks, pores and/or defects, on a surface or outer surface. The cracks can, for example, have a length of 1 mm (millimeter) to 20 mm, a crack width of 0.01 mm to 5 mm and/or a crack depth of 0.1 mm to 20 mm. The pores can have a diameter of 0.1 mm to 0.2 mm and/or a depth of 0.05 mm to 0.1 mm, for example. The surface defects can lead to a mechanical weakening of the workpiece and/or impair an external appearance of the workpiece.

In a step a), the surface defect or defects of the workpiece is measured or scanned with a 3D scanner. The entire workpiece, just an area of the workpiece with the surface defect, or just the surface defect can be measured or scanned. The measurement includes in particular a determination of a three-dimensional shape of the surface defect. Furthermore, the measurement can in particular include a determination of a three-dimensional shape of the entire workpiece or only part of the workpiece with the surface defect. The 3D scanner can be designed in the manner of a laser scanner, for example. The workpiece or the surface defect of the workpiece can be measured and/or scanned by the 3D scanner, in particular with the aid of a laser beam. For this purpose, the 3D scanner can scan the workpiece or the surface defect of the workpiece with the laser beam, in particular line-like or grid-like. The 3D scanner generates measurement data, in particular digital and/or mathematical, which can include, for example, a three-dimensional image and/or an actual geometry of the workpiece and/or the surface defect. In particular, repair data can be generated and/or calculated by the measurement data of the 3D scanner. The repair data can be generated and/or calculated using a computer in particular.

In step b) the surface defect is repaired with a 3D printer depending on the repair data. For this purpose, the workpiece can be arranged, for example, in the 3D printer and/or on a base plate of the 3D printer. The term "repair" means in particular the elimination and/or removal of the surface defect to understand. The repair data can include control data for the 3D printer, for example. In particular, the repair data can include the three-dimensional image of the surface defect. In particular, this can mean that the 3D printer is controlled using the (generated) repair data. The repair data can in particular include the three-dimensional image of the surface defect. In particular, when repairing the surface defect, the 3D printer fills the surface defect with a same material as the workpiece is made of. The material can thus in particular be brass, copper or a copper alloy. The material applied by the 3D printer can fuse with the material of the workpiece. In addition, the material applied by the 3D printer can be connected to the flawless material of the workpiece. In particular, the 3D printer is used to reconstruct or add a volume of the workpiece that is missing as a result of the surface defect. For this purpose, the 3D printer can perform a (real) laser welding process. Furthermore, the 3D printer repairs the surface defect in particular in such a way that the actual geometry of the workpiece after the repair (substantially) corresponds to a target geometry of the workpiece. After the surface defect has been repaired, the workpiece can be at least partially ground, polished, galvanized and/or chrome-plated. In particular, an etching process is not required. In particular, after the surface defect has been repaired, the surface defect is no longer visible.

The workpiece can be a component for a sanitary fitting. Such a sanitary fitting serves in particular to provide a liquid, in particular water, as required at a washbasin, a sink, a shower and/or a bathtub. For this purpose, the sanitary fitting can have a mixing valve or a mixing cartridge, by means of which cold water with a cold water temperature and hot water with a hot water temperature can be mixed to form a mixed water with a desired mixed water temperature. The cold water temperature is in particular a maximum of 25° C. (Celsius), preferably 1° C. to 25° C., particularly preferably 5° C. to 20° C. and/or the hot water temperature is in particular a maximum of 90° C., preferably 25° C. to 90° C. more preferably 55°C to 65°C. The mixing valve or the mixing cartridge are regularly arranged in a fitting housing of the sanitary fitting and/or can be actuated by means of at least one actuating element, for example in the manner of a lever, for setting the mixed water temperature and/or a flow rate of the liquid. The faucet housing can include an outlet that can be connected to the faucet housing in a fixed or pivotable manner. The mixed water can be discharged, for example, via a jet generator, aerator and/or a nozzle to an area surrounding the sanitary fitting. The component can in particular be the fitting housing, the outlet, the actuating element, the jet former, the aerator and/or the nozzle.

In step b), the 3D printer can use powdered material to repair the surface defect. For this purpose, the powdery material can be provided, for example, in the 3D printer and/or on the base plate of the 3D printer. The powdered material can be powdered metal, for example. The powdered material includes a large number of particles. In particular, the powdered material can be provided in the form of a powder bed. Furthermore, 3D printing can include building up the volume of the workpiece at least partially in layers by partial irradiation or exposure of the powdery material. The irradiation can be carried out, for example, by a laser beam or an electron beam. Furthermore, the irradiation leads to a melting of the particles of the powdery material at the irradiated point of the powdery material, so that the individual particles of the powdery material connect to one another. Building up the volume in layers can be understood, for example, as meaning that a plurality of layers are formed one after the other or layer by layer. A layer essentially describes a horizontal cross-section through the workpiece. In this context, it can also be provided that the layered construction is carried out in or with a powder bed of the powdered material. 3D printing can be done, for example, using selective laser melting (SLM) or selective laser sintering (SLS).

The powdery material can consist at least partially of brass, copper or a copper alloy.

The surface defect can be machined before step a). The mechanical processing can include, for example, smoothing a surface of the surface defect. Mechanical processing can enlarge the original surface defect by removing material from the workpiece into a finished surface defect. This can also mean that the original surface defect is completely removed by the mechanical processing and/or the reworked surface defect is created by the mechanical processing. After the mechanical Bear During processing, the reworked surface defect can be measured with the 3D scanner in step a) and/or repaired with the 3D printer in step b).

Mechanical processing can include drilling or milling.

A flat surface can be created by mechanical processing. The flat surface can be, for example, a bottom of the surface defect or of the reworked surface defect. The flat surface is generated in particular in such a way that the flat surface forms a highest point of the workpiece after the workpiece has been arranged in the 3D printer or on the base plate of the 3D printer. This makes repairs easier with the 3D printer.

The flat surface can be aligned horizontally in step b). In particular, this can mean that the flat surface is horizontal when the workpiece is in the 3D printer or on the base plate of the 3D printer.

When generating the repair data, measurement data from the 3D scanner can be compared with the geometry data of the workpiece. This can mean, for example, that the actual geometry determined by the 3D scanner in step a) is compared with a target geometry. The repair data can then be generated in particular as a function of a deviation of the actual geometry from the target geometry. The target geometry is in particular a desired geometry of the workpiece without surface defects. The actual geometry is in particular an actual geometry of the workpiece. The measurement data from the 3D scanner, the geometry data of the workpiece, the target geometry of the workpiece and/or the actual geometry of the workpiece can be present, for example, in the form of a mathematical model and/or CAD data (computer-aided design data). The repair data can in particular be generated with the aid of a computer and/or with the aid of software.

When generating the repair data, an actual geometry of the workpiece determined by the 3D scanner can be subtracted from a target geometry of the workpiece. The subtraction leads to a difference that corresponds in particular to an external shape of a defective body. The defective body is a body that has to be added to the workpiece in step b) by the 3D printer in order to repair the surface defect and/or to generate the target geometry of the workpiece. The repair data thus include, in particular, data that can be used to instruct the 3D printer to produce the defective body.

• 1: ein Verfahren zur Reparatur eines Oberflächenfehlers eines Werkstücks in einem Flussdiagramm;
• 2: ein Werkstück mit einer Sollgeometrie;
• 3: das Werkstück mit einem Oberflächenfehler;
• 4: das Werkstück mit einem nachbearbeiteten Oberflächenfehler; und
• 5: ein Fehlteil einer Istgeometrie des in der 4 gezeigten Werkstücks.

The proposed invention and its technical environment are explained in more detail below with reference to the figures. It should be pointed out that the invention should not be limited by the exemplary embodiment shown. In particular, partial aspects of the facts explained in the figures can be extracted and combined with other parts of the description. It shows as an example and schematically:

• 1 : a method for repairing a surface defect of a workpiece in a flowchart;
• 2 : a workpiece with a target geometry;
• 3 : the workpiece with a surface defect;
• 4 : the workpiece with a finished surface defect; and
• 5 : a missing part of an actual geometry in the 4 workpiece shown.

1 shows a method for repairing a surface defect 1 in the 3 shown workpiece 2 or a reworked surface defect 8 in the 4 shown workpiece 2 in a flow chart. In a step a), the surface defect 1 or the reworked surface defect 8 is measured or scanned with a 3D scanner to generate repair data. Subsequently, in a step b), the surface defect 1 or the reworked surface defect 8 can be repaired with a 3D printer depending on the repair data.

2 shows the workpiece 2 in a side view. The workpiece 2 is a component 3 for a sanitary fitting, the component 3 being designed in the manner of a fitting housing. The workpiece 2 has in the 2 a target geometry 6.

3 shows the workpiece 2 in a side view, the workpiece 2 having a surface defect 1 in the form of a crack on a surface 7 .

4 shows the workpiece 2 in side view after the in the 3 shown surface defect 1 was machined. The mechanical processing was carried out using a milling cutter, so that a flat surface 4 was formed on the surface 7 of the workpiece 2 . The workpiece 2 therefore has in the 4 a reworked surface defect 8 in the area of the flat surface 4. In step a) of the method the reworked surface defect 8 is measured or scanned with a 3D scanner (not shown here) to generate the repair data. For this purpose, an actual geometry 5 of the workpiece 2 is determined with the 3D scanner. The actual geometry 5 of the workpiece 2 can then with the in the 2 shown target geometry 6 of the workpiece 2 compared or from that in the 2 shown target geometry 6 of the workpiece 2 are subtracted. As a result, a geometry is one in the 5 shown missing part 9 determinable, which is in the 4 Actual geometry 5 shown in comparison to that in FIG 2 shown target geometry 6 is missing. Repair data can be generated from the geometry or shape of the missing part 9 . In step b) the reworked surface defect 8 of the 4 shown workpiece 2 repaired with the 3D printer, not shown, depending on the repair data. For this purpose, the workpiece 2 is arranged in the 3D printer in such a way that the flat surface 4 runs horizontally. Then on the flat surface 4 of the workpiece 2 by the 3D printer in the 5 Missing part 9 shown are printed, so that the workpiece 2 then in the 2 shown target geometry 6 has.

The invention allows a surface defect in a workpiece made of brass, copper or a copper alloy to be repaired at low cost.

Reference List

1

surface defects

2

workpiece

3

component

4

flat surface

5

actual geometry

6

target geometry

7

surface

8th

reworked surface defect

9

missing part

Claims (10)

Method for repairing a surface defect (1, 8) of a workpiece (2), which consists at least partially of brass, copper or a copper alloy, comprising at least the following steps: a) Measuring the surface defect (1, 8) with a 3D scanner to generate repair data; and b) Repairing the surface defect (1, 8) with a 3D printer depending on the repair data. procedure after Claim 1 , wherein the workpiece (2) is a component (3) for a sanitary fitting. Method according to one of the preceding claims, wherein in step b) the 3D printer uses powdered material to repair the surface defect (1, 8). procedure after patent claim 3 , wherein the powdery material consists at least partially of brass, copper or a copper alloy. Method according to one of the preceding claims, in which the surface defect (1, 8) is machined before step a). procedure after Claim 5 , wherein the mechanical processing includes drilling or milling. procedure after Claim 5 or 6 , wherein a flat surface (4) is produced by the mechanical processing. procedure after Claim 7 , wherein the flat surface (4) is aligned horizontally in step b). Method according to one of the preceding claims, wherein measurement data of the 3D scanner are compared with geometric data of the workpiece (2) during the generation of the repair data. Method according to one of the preceding claims, wherein when generating the repair data, an actual geometry (5) of the workpiece (2) measured by the 3D scanner is subtracted from a target geometry (6) of the workpiece (2).

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