Abstract
The invention relates to a material feeding device. The material feeding device according to the invention to be used in a material processing device has a material feeding channel with an output end facing a processing site during operation of the material feeding device, and is characterized in that the material feeding device has at least one microchannel.
Claims
1. Material feeding device to be used in a material processing device, the material feeding device having at least one material feeding channel, the material feeding channel having an output end facing a processing site during operation of the material feeding device, wherein; the material feeding device has at least one microchannel, the at least one microchannel having, at least in one place, a wall thickness of less than 0.5 mm, and being connected to a coolant supply.
2. Material feeding device according to claim 1, wherein; the material feeding device has a central material feeding channel.
3. Material feeding device according to claim 1, wherein; the material feeding device has a material feeding channel arranged laterally at an angle larger than 0° and smaller than 90° to the axis of a beam guide.
4. Material feeding device according to claim 1, wherein; the at least one microchannel has an integrated support.
5. Material feeding device according to claim 1, wherein; the at least one micro-cooling channel ensures a temperature control medium forward flow and a temperature control medium return flow.
6. Material feeding device according to claim 1, wherein; the material feeding device has an area with a thread for receiving and fixing a nozzle tip into place, with microchannels cutting through the material feeding device at least except for the thread area.
7. Material feeding device according to claim 1, wherein; a measurement sensor is provided in at least one microchannel.
8. Material feeding device according to claim 1, wherein; a material influencing device is provided in at least one microchannel.
9. Manufacturing method for a material feeding device according to claim 1, wherein; the manufacturing method is from the method class of additive manufacturing methods.
10. Manufacturing method according to claim 9, wherein; the manufacturing method uses laser powder bed fusion technology.
11. Material feeding device according to claim 1, wherein the wall thickness is less than 0.3 mm.
12. Material feeding device according to claim 1, wherein the wall thickness is less than 0.2 mm.
Description
[0035] In the figures:
[0036] FIG. 1 shows a processing head of a material processing device,
[0037] FIG. 2 is a three-dimensional presentation of a material feeding device according to the invention,
[0038] FIG. 3 is a longitudinal section of an embodiment of a material feeding device according to the invention,
[0039] FIG. 4 is a longitudinal section of another embodiment of a material feeding device according to the invention,
[0040] FIG. 5 is an enlarged cross-section of the material feeding device according to the invention from FIG. 4.
[0041] FIG. 1 shows a processing head 200 of a material processing device. The processing head 200 has a material feeding device 100 according to the invention with a material channel 110. The material feeding device according to the invention, to be used in a material processing device, has a material feeding channel 100 with an output end 111 which during operation of the material feeding device 100 faces a processing site. By means of the material feeding device 100, a material can be fed to a processing site on a substrate. The material processing device is used to perform material processing methods, for instance a laser welding method. The processing head 200 has a guiding device for laser beams. This guiding device has deflection units 215 for laser beams, for instance mirrors and/or prisms, a focusing lens 210 and further an inert gas nozzle 230 with an inert gas channel 235. Through the inert gas channel 235, inert gas is fed to the processing site. The inert gas prevents scaling of the substrate which is hot at the time of processing, or of the supplied material, respectively, by temporarily screening the processing site from contact with oxygen. In the embodiment shown, material is centrally, i. e. axially to the longitudinal axis of the processing head 200, fed to the processing site. For this purpose, if one or more laser beams are employed, the laser beam(s) must be divided such that the central axis becomes or remains free for material feeding. To achieve this, all components in the processing head, that is, in particular the material feeding device 100, must be embodied and the laser beam(s) must be conducted such in an optical channel 220 (in the embodiment shown in a laser-beam ring 220) that the beam guidance is not impaired, in particular such that the beam(s) is/are not shielded off. The material feeding channel 110 has at its end opposite the processing site an exchangeable material nozzle (not shown). This material nozzle can be, for instance, screwed into the material feeding channel 110. During operation, wear occurs on the end of the material feeding channel 110 opposite the processing site, among others due to the thermal load to which this end of the material feeding channel 110 is subjected during operation of the processing head 200. The exchangeable material nozzle can be easily replaced when wear has surpassed a critical limit. The material can be fed in solid, liquid or gaseous form. In solid form, it is generally a wire or a powder. If the material fed in has the form of a wire, for example, wear can result in an enlargement of the diameter of the material feeding channel 110 at the output end 111, impairing precision of the wire guidance.
[0042] FIG. 2 is a three-dimensional presentation of a material feeding device 100 according to the invention. The material feeding device 100 has a continuous material feeding channel 110 through which the material is fed to the processing site. Furthermore, the material feeding device 100 has media connecting ports 130. Via these media connecting ports 130, for instance a cooling medium, such as water, can be conducted into and out of the material feeding device 100. The media connecting ports 130 are located at the end of the material feeding device 100 which, during operation of the processing head 200, is opposite the processing site. In addition, the material feeding device 100 has a connecting port 120 for a material nozzle (not shown) which is arranged, during operation of the processing head 200, to be screwed into the end of the material feeding device 100 facing the processing site. Further, a connecting piece 150 can be seen in the Figure to which the material feeding device 100, which for manufacturing reasons has a two-part configuration, is attached. The material feeding device 100 is manufactured by means of an additive manufacturing method. If the parts to be manufactured in the additive manufacturing plant are limited in size, the material feeding device 100 can be manufactured in two or more parts and be assembled for operation at one or more connecting pieces 150. The material feeding device 100 can also be produced in one piece, however, provided that a respective additive manufacturing plant is available.
[0043] FIG. 3 is a longitudinal section of an embodiment of a material feeding device 100 according to the invention. As in FIG. 2, media connecting ports 130 and the connecting port 120 for the material nozzle can be seen, the presentation of the thread missing in this Figure for the purpose of clear presentation. The material feeding device 100 has a continuous material feeding channel 110. Furthermore, the material feeding device 100 has several media channels 131 which are operatively connected to the media connecting ports 130. For instance, a cooling medium, such as water, can be conducted into a medium channel 131 through a medium port 130. The medium channels 131 are embodied as microchannels 131, that is, as tubular channels with very small cross-sections, for instance 10.sup.−2 mm.sup.2. A microchannel 131 can be partly or entirely annular, elliptical, polygonal, helical or even straight. Several microchannels 131 can comprise both various microchannels 131 which are not interconnected and various interconnected microchannels 131 or different windings of a helical microchannel 131. A microchannel 131 can also be embodied as a double-walled channel, for instance as a channel inside a channel and/or as a helical channel. The microchannel 131 is limited by a wall. The wall can form the border to the outside of the material feeding device 100 or to another channel. This other channel can be an additional microchannel 131, a material feeding channel 110 or an optical channel 220. The additional microchannel 131 can also be an additional winding of a helical microchannel 131. Each microchannel 131 can have a wall thickness, at least in one place, of less than 0.5 mm, preferably less than 0.3 mm and particularly preferably less than 0.2 mm. The low wall thickness of the microchannel 131 allows a very small structural size of the material feeding device 100 which nevertheless allows, for instance, temperature regulation. Microchannels 131 cut through the material feeding device 100 at least except for the thread area for screwing the material nozzle (not shown in the Figure) into place. By increasing the area of the material feeding device 100 where microchannels 131 pass through, temperature control of the material feeding device 100 is optimized. It is also possible to introduce measurement sensors into one or more microchannels 131 of the material feeding device 100 close to the material feeding channel 110. Such measurement sensors can be, for instance, temperature sensors for monitoring the temperature of the material feed, optical fibers for recording the weld pool temperature and/or for process control, sensors for distance measurement, for instance an optical fiber for OCT (optical coherence tomography, an imaging method for receiving two- and three-dimensional images from scattering materials in micrometer resolution), or measurement sensors for monitoring the material feed conveyance. By the introduction of such measurement sensors, process parameters can be monitored very closely to sites of interest in the interior of the material feeding device 100 and/or to the processing site without a substantial change in size of the material feeding device 100.
[0044] Alternatively or in addition, an filler material influencing device can be provided in at least one microchannel 131. Such an influencing device can be, for instance, a device for preheating the filler material, for instance an inductive preheating unit. By preheating the material to be fed in, for instance the application rate of material, for example of filler material, can be increased. By introducing a material influencing device in a microchannel 131, the filler material influencing device can be approached, for example, very closely to the material feeding channel 110, in particular very closely to the processing site, so that the filler material can be influenced with high precision in a targeted manner.
[0045] The material feeding device 100 is manufactured by means of an additive manufacturing method. By constructing the material feeding device 100 in layers, geometries such as the microchannels 100 described above can be manufactured which cannot be manufactured at all or only at great effort with conventional manufacturing methods.
[0046] FIG. 4 shows a longitudinal section of another embodiment of a material feeding device 100 according to the invention. The microchannel 131 has an integrated support 132 or a plurality of such supports 132. The support 132 can ensure a turbulence or an increase in turbulence in the temperature control medium flowing through the microchannel 131 and thus ensure optimized heat transfer. In addition, the support 132 can also contribute to mechanical stability of the microchannel 131 and of the material feeding device 100.
[0047] FIG. 5 is an enlarged section of a material feeding device 100 according to the invention from FIG. 4. In this enlarged section, the supports 132 are easier to see. The supports 132 are applied on the interior, that is, on the side of the microchannel 131 facing the material feeding channel 110. The supports 132 can also be arranged, however, in any other place within the microchannel 131.
[0048] The embodiments shown here are only exemplary and are therefore not to be intended as limiting. Alternative embodiments considered by the person skilled in the art are equally comprised by the scope of protection of the present invention.
LIST OF REFERENCE NUMBERS
[0049] 100 material feeding device [0050] 110 material feeding channel [0051] 111 output end [0052] 120 connecting port for a material nozzle [0053] 130 medium connecting port [0054] 131 medium channel, microchannel [0055] 132 support [0056] 150 connecting piece [0057] 200 processing head [0058] 210 focusing lens [0059] 215 deflection unit [0060] 220 optical channel, laser beam ring [0061] 230 inert gas nozzle [0062] 235 inert gas channel
