METHOD FOR PRODUCING THROUGH-HOLES IN A WALL OF A COMPONENT, BY MEANS OF LASER RADIATION

Abstract

A method for producing through-holes in a wall of a component, by laser radiation is provided, that includes a wall delimiting a cavity in which a protection agent is provided that can be liquefied when heated. According to the method, through-holes are successively produced in the wall of the component in a plurality of defined points, two directly subsequent through-holes being produced such that a through-hole is produced in a predetermined point and the next through-hole is produced in an additional point which is further away from the predetermined point than at least two, in particular three or more omitted points that are closer to the predetermined point, and/or are produced such that a through-hole is produced in a predetermined point and the next through-hole is produced an additional point.

Claims

1-6. (canceled)

7. A method for producing through-holes by laser radiation in a wall of a component, which delimits a cavity in which provision is made for a protective agent which can liquefy under heat, comprising: introducing through-holes consecutively into the wall of the component at a multiplicity of defined drilling positions, producing two directly consecutive through-holes in a way that a through-hole is created at a predetermined drilling position and the next through-hole is created at a further drilling position which lies further away from the predetermined drilling position than at least two drilling positions, which are omitted, which lie close to the predetermined drilling positions, and/or producing two directly consecutive through-holes in a way that a through-hole is created at a predetermined drilling position and the next through-hole is created at a further drilling position, wherein at least one drilling position, which is omitted, lies between the predetermined drilling position and the further drilling two or more drilling positions, which are omitted, lie between the predetermined drilling position and the further drilling position, in which the multiplicity of defined drilling positions comprise a plurality of rows and a plurality of lines of drilling positions, and in which two directly consecutively introduced through-holes lie in different rows and/or in different lines.

8. The method as claimed in claim 7, in which a plurality of rows and/or lines of omitted drilling positions lie in each case between two directly consecutively introduced through-holes.

9. The method as claimed in claim 7, in which in a predetermined pattern one or more nearest drilling positions and/or one or more nearest rows of drilling positions and/or one or more nearest lines of drilling positions are omitted in each case.

10. The method as claimed in claim 7, wherein the further drilling position lies at least 1.5 times, especially at least two times and preferably at least three times or at least five times further away from the predetermined drilling position than that omitted drilling position which lies nearest to the predetermined drilling position.

11. The method as claimed in claim 7, wherein as a protective agent a polymer in the liquid state is introduced by pouring or spraying or injecting, into the cavity before the multiplicity of through-holes are introduced into the wall of the component.

Description

BRIEF DESCRIPTION

[0027] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

[0028] FIG. 1 shows in a schematized sectional view a component with an almost completely closed cavity; and

[0029] FIG. 2 shows a top view of a drilling-position pattern, according to which through-holes are to be created in the upper wall of the component which is shown in FIG. 1.

[0030] FIG. 1 shows in a schematized sectional view a component 1 with a cavity 2 which is difficult to access. The cavity 2 is delimited by an upper wall 3 and a lower wall 4 of the component 1. The cavity 2 is almost completely closed off by the upper wall 3 and the lower wall 4. Only in the end region of the component 1 pointing to the right in FIG. 1 is the cavity 2 accessible via a narrow opening.

[0031] The cavity 2 of the component 1 which is difficult to access is filled with a protective agent 5, specifically a polymer, which can liquefy under heat. For introducing the protective agent 5 into the cavity 2, this has first of all been converted into the liquid state under heat and then poured into the cavity 2 via the opening in the end region of the component 1 pointing to the right in FIG. 1. There would then be a predetermined waiting time which the protective agent 5 requires in order to completely harden at the surrounding temperature.

[0032] By a laser beam 6, which is shown schematically in FIG. 1, through-holes 7 are to be introduced into the upper wall 3 of the component 1 at a multiplicity of predetermined drilling positions. In the case of the represented exemplary embodiment, through-holes 7 with a circular cross section are to be produced. Alternatively to this, any other cross-sectional shapes, for example polygonal, oval or other shapes are possible for the through-holes 7.

[0033] Specifically, provision is made for altogether 15 drilling positions A to O on the upper wall 3 at which through-holes 7 are to be produced in the upper wall 3 of the component 1 by means of the laser beam 6. This can easily be seen in FIG. 2 which shows a schematic view of the drilling-position pattern. FIG. 2 shows a top view of the drilling-position pattern. This comprises 2 lines and 5 rows of drilling positions which generate a rectangular shape.

[0034] Using the method according to embodiments of the invention, through-holes 7 are introduced into the upper wall 3 of the component 1 by means of the laser beam 6 at all the drilling positions A to O. To this end, the process is as follows.

[0035] At a predetermined first drilling position A, which lies in the first row and the first line of the drilling-position pattern, a first through-hole 7 is introduced into the wall 3 of the component 1. To this end, the laser beam 6 is oriented onto the drilling position A and material is removed by laser radiation. There is then a jump to the right into the nearest line, that is to say the middle line, and also downward into the next but one row, that is to say the middle row, of the drilling-position pattern shown in FIG. 2 to the drilling position B in the center of the pattern. In FIG. 2, the corresponding jump from the drilling position A to the drilling position B is shown schematically by means of an arrow. When jumping from drilling position A to drilling position B, the two drilling positions nearest to the predetermined drilling position A, specifically the drilling positions J and N, and also the drilling position L which has a slightly greater distance to the drilling position A than the drilling positions J and N, are omitted, therefore not provided with through-holes 7. At the further drilling position B, which lies further away from the initial drilling position A than each of the three nearer-lying omitted drilling positions J, L and N, the second through-hole 7 is then introduced. The laser beam 6 is directed onto the drilling position B for this and drilling is carried out again in order to create a further through-hole 7 in the upper wall 3 of the component 1 at the drilling position B.

[0036] For the introduction of further through-holes at further drilling positions the aforesaid steps are carried out in multiple iterations.

[0037] Specifically, starting from the drilling position B which is provided with a through-hole 7, a jump is made into the next line and the next but one row to the drilling position C. A further through-hole 7 is introduced at the drilling position C. When jumping from drilling position B to drilling position C, all the drilling positions nearest to the drilling position B, that is to say the drilling positions L, G, D and K and also the drilling positions J, I, M and H, are omitted. Starting from the drilling position C as the initial drilling position, in a further iteration a jump is made into the middle row of the drilling-position pattern to the drilling position D. In this case, the drilling positions O, K and H which lie close to the drilling position C are omitted. The drilling position H which lies between the drilling position C and the drilling position D is also skipped in the process. A further through-hole 7 is then introduced at the drilling position D.

[0038] In the aforesaid manner, as indicated in FIG. 2 by the corresponding arrows, through-holes 7 are also produced by the laser beam 6 in the upper wall 3 of the component 1 at the remaining drilling positions by further repetitions of the previously described method steps.

[0039] In the sectional view in FIG. 1, the component is shown in a state in which through-holes 7 have already been produced at some, but not yet at all, of the drilling positions A to O. Specifically, two through-holes 7 are to be seen in the step.

[0040] As a result of the deliberate omitting or skipping of close-lying drilling positions when introducing two directly consecutive through-holes 7, the heat quantity, which is introduced into the wall 3 of the component 1 and also into the cavity 2 and therefore into the liquefiable protective agent 5 provided in this as a result of the multiplicity of laser drilling processes carried out one after the other, is distributed to regions which lie further apart. The protective agent 5 can therefore completely cool down in and around the region of a drilling position at which a through-hole 7 has just been produced before returning to a drilling position, which lies nearest to this, and a further through-hole 7 is introduced there. The local heating up of the protective agent 5 provided in the cavity 2 of the component 1 is consequently reduced. This is achieved by the energy input into the protective agent 5 per time unit or volume unit being reduced as a result of the deliberate omission of nearest drilling positions and/or as a result of the deliberate skipping of nearest drilling positions.

[0041] In this way, the effect of the protective agent 5 being locally heated up to a high degree as a result of the production of a plurality of through-holes 7 lying closely next to each other during the laser machining process is reliably prevented. The protective agent 5 is thereby not liquefied and therefore does not flow out of the cavity 2 either. As a result, the protective agent 5 is reliably available in the cavity 2 for protection of the rear-side wall 4 of the component 1 at all times when introducing the through-holes 7 into the upper wall 3.

[0042] Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0043] For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.