AT506999A1 - METHOD AND DEVICE FOR REPAIRING DAMAGE TO A METALLIC SUBSTRATE - Google Patents

Description

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The invention relates to methods for repairing damage to a region of a first surface and / or below the first surface area with a damage to a metallic substrate, in particular an endless sheet-metal strip, as well as to a device for making a recess in a Substrate and for welding a filler,

From AT 404 570 B a device for cutting and welding of circular blanks in a metal sheet is known. Sheets which have to have a particularly high surface quality, for example a roughness RA of 0.2 μm, are preferably used in double belt presses. The nature of the sheet causes the desired surface quality of the same during production, for example of chipboard. For major damage to the surface of the belt, a circular cutout showing the damage is removed from the belt for repair. The corresponding cutting device is arranged on a guide, so that the circular cut-out can be particularly uniform. In this section, a prefabricated sheet metal blank is used, which is held from below, for example with a Kupferplätte. There then takes place an electrical welding with a TIG welding device and with the metal equivalent welding filler material. The weld is cold forged, abraded to the thickness of the sheet metal strip, and then the weld is ground again. This method is suitable for repairing major damage to the sheet metal strip. Such circular blanks have for example a diameter of 300 mm. However, this method is not suitable for small damage, such. From 30 pm to 200 pm. Such small damages may occur preferentially in welds, which may result in damage to the 900 • · · · · · · · ··················· 9 0 900 ·· 09 000 00 9 - 3 -

Weld seam voids are present, which pretend an intact weld, but may result in prolonged operation to break up the voids, so that then a damage to the surface is formed.

The object of the present invention is to provide a method or device which is suitable for repairing relatively small damage, for example from 20 μm to 1 mm in diameter, and which is carried out quickly, simply and with particular accuracy can be, with the tape on which the repair is to take place in the system, for example, a double-belt system, may remain.

The inventive method for repairing a damage to a region of a first surface and / or under the first surface area lying with a damage to a metallic substrate, in particular an endless sheet-metal strip, wherein the region, in particular machined, z. B. by milling, is removed from the substrate, and in a circular recess thus obtained, a metallic filler with the substrate, in particular electrically, is welded, followed by one, esb nder s pana lifting, processing takes place and optionally subsequently polished, and The substrate has a further surface, which lies opposite the first surface, consists essentially in the fact that in the production of the recess, the entire metallic substrate for the recess is removed, in particular crushed, and ends in front of the other surface, and a filler with a maximum diameter is greater than that of the recess is welded.

The areas with damage should z. B. machined, in particular by milling but also with laser or electroerodating, from the ····· ······················································································· · · · · · · · · · · · · · · · · · · · ·

Substrate are removed in order to achieve a particularly accurate size limitation of the area to be repaired. With a circular recess no special insertion of the filler must be done, but the position of the filler can be chosen arbitrarily. As a result of the subsequent machining, in particular machining, a leveling can be achieved with respect to the subsequent first surface of the metallic substrate. In order to match the surface quality of the surface quality of the subsequent metallic substrate, optionally polished.

If the recess is machined in its entirety by comminution of the entire metallic substrate in this area, a particularly accurate production of the recess can take place, as it is of particular importance for small dimensions, for example 30 .mu.m to 200 .mu.m.

If the recess terminates in front of a further surface which lies opposite the first surface, no machining is required on the further surface and no mechanical reworking, such as polishing, is required.

If the filling piece has a larger maximum diameter than that of the recess, then a particularly good filling of the recess by the filling piece can be achieved.

If a rotationally symmetrical filler piece is welded in, a particularly simple insertion of the filler into the recess can take place. If an ellipsoid of revolution is present, then, for example, in the case of a milling cutter, which partially has the shape of an ellipsoid of revolution, an exact fitting into the recess can take place, whereby only the axis of rotation of the recess can be determined. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

Rotary ellipsoids to coincide with the imaginary axis of the milling cutter.

If the filler piece is in the form of a ball, it can be inserted into the recess without rotation via axes of rotation or the like, and then welded in place.

With both embodiments, the air between the recess and the filler can escape particularly well.

If the welding of the filler in the recess with a permanent electrode via a surge, so it can be done in a simple and fast way a full-surface connection of the filler with the surface of the recess.

If the milling and welding of a movable over the substrate device, so several damages can be successively repaired very easily.

If the milling and the subsequent welding from only one point of the device performed on the substrate, so the required precision in milling the recess and the insertion of the filler and the required subsequent welding is given.

If the device is held on the substrate during the milling of the recess, the welding and optionally subsequent milling on the substrate, in particular via electromagnets, an accurate positioning of the device can take place. The attachment of the device to the substrate can be done, for example, via suckers made of rubber-elastic material. Magnetic holding can also be used in dia- and paramagnetic • • • • • • • • • • • • • • • • • • • • • • • • • · '•' • • • ·· ·· ··· ·· • • • · - 6 -

Substances are carried out. It is only necessary that on the other side of the metallic substrate, an armature, such as a soft iron anchor, is arranged, which is held by the electromagnet, whereby at the same time the device is pressed against the substrate.

A particularly homogeneous repair of the damage can be achieved if a to the substrate of the same or provided with the same composition filler is welded.

If a part of the filler protruding beyond the first surface, in particular to a small extent above the first surface, is in particular milled off, the repair can be effected simply and quickly with equalization in the region of the damage.

If the part of the filling piece which protrudes beyond the first surface is worked off with a milling cutter having a flat working surface which has a diameter which corresponds at least to the maximum diameter of the filling piece, then with one working operation and with only one position of the milling cutter by lowering the same in the direction of the first surface equalization done. This lowering can be stopped via a stop for the holder exactly in the plane of the first surface.

If the recess is milled with a face milling cutter, the bottom of the recess can also be adapted particularly well to the shape of the filler piece. •; • • • 4 ·· • ······

When milling with a milling cutter which has a concave working surface which is part-spherical, all the advantages of a spherical filling piece can be achieved particularly easily. It must be performed when inserting the ball no special positioning, further a full-surface concerns of the ball can be reached in the recess and air entrapment can be avoided.

If a recess with a depth corresponding to 5% bis'4.0 '%, in particular 15% to 3 0%, of the filler milled, so in a particularly simple manner leakage of gases, in particular air between the filler and the walls of the Recessed.

The inventive device for making a recess in a metallic substrate and for welding a metallic filler, in particular for carrying out the method according to the invention, with a variable-height cutter and a variable-height electrode, each based on a first surface of a substrate, a, in particular with compressed gas operating motor for the router, consists in

Essentially in that a, in particular height-adjustable, stop for the cutter for the recess is provided in its movement to the first surface of the substrate, and the electrode is a permanent electrode without welding consumables.

Holc h the höhenve ränderlichen Fr äse r recesses can be made with different depths with one and the same device, the depth of the recess can be specified via a stop for the cutter, so that the required accuracy can be kept particularly simple. • ··· f · · · · · · · · · · ··· ··············· ·· - 8th -

By the electrode without welding consumables can be done a simple and accurate electrical welding, the electrode only against the filler, in particular the vertex of the same, must be driven and brought into abutment.

If the milling cutter and the permanent electrode can be moved successively over a region with damage in the case of a device arranged above the substrate, the repair can be carried out with particularly high precision.

If two cutters with different working widths are provided, the milling of the cutout as well as the removal of the filling piece projecting beyond the first surface can be carried out with one position of the device.

In the following the invention with reference to the drawing and an example will be explained in more detail.

Show it:

Fig. 1 shows a section through the substrate with weld and

Fig. 2 shows a device for milling and welding.

In Fig. 1 is a section through a metallic substrate 1 with a roughness RH of 0.2 pm, namely a section of an endless steel strip with a chromium nickel steel with 15 wt .-% chromium, 7 wt .-% nickel, 0, 7 wt .-% copper and 0.4 wt .-% titanium, shown. The thickness di of the metallic substrate is 2.00 mm. The metallic substrate has a first surface 2 and a surface 3 opposite thereto. Of the • · • · • · • ·

····· Μ ···· 9

Section through the substrate was performed on a weld 4, which has a recess 5. In this recess 5, a spherical filler 6 is arranged, which has a radius R of 300 μιη. The filler 6 has an identical metallurgical composition as the metallic substrate. The circular extent d3 of the recess in the plane of the first surface 2 is about 480 μιη. The depth d2 of the recess 5 is 120 μιη, based on the plane of the first surface.

In FIG. 2, the device according to the invention rests with a plate 7 on the first surface 2 of the metallic substrate 1. The plate has electromagnets 8, which, if necessary, cooperate with a soft iron anchor, not shown, which can be arranged opposite the first surface 3 opposite surface. The plate 7 carries a boom 9 with a cantilevered arm 10 in which a pivoting piece 11 is mounted. This pivoting piece 1 1 has notches, so that alternately at least one milling cutter 12 or a permanent electrode 13 can be pivoted into the same position above the first surface 2. The cutter 12 with a concave spherical working surface 12a is mounted in a holder 14 which has a threaded piece IS which is connected to this

Threaded piece IS surrounding threaded piece 16 cooperates with a female thread. This threaded piece 16 can be lowered and raised via a knurled nut 17, wherein the knurled nut 17 itself allows a fixable micro-adjustment for lowering and raising the cutter and a stepper motor with rotating cutter (not shown). Through the threaded pieces 15 and 16, a stopper is formed. Through the threaded part 15, a shaft 19 is guided, which is connected to the holder 14 and the motor 18. Cylindrical Shaft 19 ····· ··· · · · · ··· ··· · · · · · · ············································································ ··· ··· - 10 - has at the top of a hexagon, which cooperates with a corresponding recess in the motor 18, so that the drive of the milling cutter is ensured in the different height positions.

The permanent electrode 13, which is connected as an anode, has a holder 20, with at its upper end a threaded piece 21 which cooperates with a further threaded piece 22, so that the knurled nut 23, the threaded piece 20 and thus the electrode on the vertex the filler can be lowered and lifted. The knurled nut 23 is actuated via a stepper motor (not shown).

The device may also have another end mill with a flat working surface with a diameter of 2 mm, ie more than 600 pm, for removing the filler with the part that projects beyond the first surface, so that it does not correspond deeper than the position of the first surface , is milled off.

Example:

The weld 4 is made with a two-dimensional hand-held microscope. after superficial voids and visually for pores or the like. After finding an area with damage, the device with cutter and permanent electrode is placed over the area to be repaired, and fixed with the electromagnets 8 in this position. Then, via the motor 18 operated by compressed air, the cutter 12 is set in rotation, and moved with the stepping motor in the direction of the first surface 2 until the holder 14 abuts the stop, formed by the threaded pieces 15, 16 and knurled nut 17, and the Depth d2 of 120 pm is reached. The cutter 12 has a ····· ···························································································. ························································································································································ After the recess 5 is made, the spherical filler 6 with a diameter of 600 .mu.m, which, as already stated, the same chemical composition as the metallic substrate 2, is used. The cutter 12 with the dome-shaped working surface 12a is raised before inserting the ball in the recess and rotated in a rest position. Then, a permanent electrode 13 is pivoted about the spherical filler 6 and then lowered to the apex of the filler. There is a current surge of 8.0 volts, 10.0 amps for 0.3 seconds. The permanent electrode 13 is connected as an anode and the metallic substrate as a cathode. After welding of the spherical filler 6 in the recess 5, the permanent electrode 13 is raised and then an end mill on the area pivoted, which has a flat work surface. With this cutter, the protruding part of the filler is milled to the plane in which the first surface is located. Then, the area of remaining in the recess portion of the spherical filler, z. B. dog with polishing sandpaper, polished. The filler may also have the shape of an ellipsoid of revolution.

The recess can also take place with laser, by drilling, galvanic, wire eroding or the like by removing the material of the substrate.

The removal and polishing of the filler can mechanically but also z. B. by laser beams.

Claims (16)

• · · · ······· • · • · • · Claims 1. A method for repairing damage to a region of a first surface (2) and / or under the first surface (2) lying area with a damage to a metallic substrate (1), in particular an endless sheet-metal strip, wherein the area, in particular machined, z. B. by milling, from the substrate (1) is removed, and in a thus obtained circular recess (5) a metallic filler (6) to the substrate (1), in particular electrically, is welded, followed by a, in particular machining, machining is carried out and optionally subsequently polished, and the substrate (1) has a further surface (3), which lies opposite the first surface (2), characterized in that in the production of the recess (5) the entire metallic substrate (1) for the recess (S) is removed, in particular crushed, and in front of the further surface (3) terminates, and a filler (6) having a maximum diameter (2R) greater than that of (d3) of the recess (5) is welded. 2. The method according to claim 1, characterized in that a rotationally symmetrical filler (6), in particular a ball or ellipsoid of revolution, is welded. 3. The method according to claim 1 or 2, characterized in that with a surge through a permanent electrode (13), the filler (6) in the recess (5) is welded. 4. The method of claim 1, 2 or 3, characterized in that the milling and welding of a movable over the substrate device (Fig. 2) takes place. •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• · -.1-3 ·· - 5. The method according to claim 4, characterized in that the milling of the recess (5) and the subsequent welding of only one point of the device (Fig. 2) over your substrate (I) are performed. 6. The method according to any one of claims 1 to 5, characterized in that the device (Fig. 2) during milling, welding and optionally subsequent milling on the substrate (1), in particular via electromagnets (8), is held on the substrate. 7. The method according to any one of claims 1 to 6, characterized in that a filler (6), the (1) of the same or identical composition to the substrate, is welded. 8. The method according to any one of claims 1 to 7, characterized in that over the first surface (2) projecting part of the filler (6), in particular to slightly above the first surface (2), processed, in particular milled, is. 9. The method according to claim 8, characterized in that over the first surface (2) projecting part of the filler (6) with a cutter with a working surface having a diameter which corresponds at least to the maximum diameter (2R) of the filler, is processed. 10. The method according to any one of claims 1 to 9, characterized in that the recess (5) is milled with a face milling cutter. • 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 999 99 ··· ·· 9 999 - 1 4 - 11. The method according to any one of claims 1 to 10, characterized in that the recess (5) with a milling cutter (12) is milled, which has a concave surface (12a) which is partially spherical. 12. The method according to any one of claims 1 to 11, characterized in that a recess (S) having a depth (d2), the 5% to 40%, in particular 15% to 3 0%, of the maximum diameter (2R) of the filler corresponds, is milled. 13. An apparatus for making a recess (5) in a metallic substrate (1) and for welding a filler (6), in particular for carrying out the method according to claims 1 to 12, wherein with a height-adjustable cutter (12) and a höhenveränderlichen Electrode (13), in each case based on a first surface (2) of a substrate (1), a motor (.19) operated in particular by compressed gas for the milling cutter (12), characterized in that a stop (in particular variable in height) (FIG. 15, 16, 17) for the cutter (12) for the recess (5) in its movement to the first surface (2) of the substrate (1) is provided, and the electrode (12) is a permanent electrode (13) without welding consumables. 14. The apparatus according to claim 13, characterized in that the milling cutter (12) and the permanent electrode (13) are movable in succession over an area with a damage over the substrate (1) fixedly arranged device. ····· ······························································································· · - 15 - 15. The apparatus according to claim 13 or 14, characterized in that the stop (15, 16, 17) for the cutter (12) for the recess (5) with respect to the first surface (2) of the substrate (1), especially stepless, höhettveränderlich. 16. The apparatus of claim 13, 14 or 15, characterized in that the device has two cutters with different working width. FOR D. ANMEjfc.DER (IN); 2 1. m 2008 patent DIPL ING. WÄÄETM CASATI DIPLINFFIFFER 1TZE