Device for the production of three-dimensional components

Abstract

Device for producing three-dimensional components which, after the construction process, consist of a prefabricated lower part and an upper part of the object generatively built thereon, wherein the upper part of the object is produced by successive solidification of layers of a radiation-solidifiable construction material (1) at the locations corresponding to the respective cross-section of the upper part of the object, and the device comprises the following: - a carrying device for carrying the object during the construction process with a height-adjustable support (5), - an application device (3) for applying the building material (1) layer by layer onto a building surface or an already formed layer and - an irradiation device (10) for the targeted irradiation of the layers of the building material (1) at the locations corresponding to the cross-section of the object, wherein - at least one body (4) is arranged on an upper side of the carrier (5), characterized in that - the body (4) is designed as a form-adapted plug-in holder (30) for at least one prefabricated object base (31) of an object to be constructed and - for this purpose, it has at least one recess (32) in which the inserted prefabricated object base can be fixed, -- wherein the at least one recess (32) is designed as an opening in the body (4), wherein the fixing of at least one inserted prefabricated object base (31) in the plug-in holder (30) is effected by generating a negative pressure which draws the inserted prefabricated object base (31) into the recess (32) of the plug-in holder in the direction of the carrier (5) and fixes it therein.

Description

[0001] The invention relates to a device for producing three-dimensional components which, after the construction process, consist of a prefabricated lower object part and an upper part which is additively constructed thereon. Such components can either be designed as hybrid components, i.e. components which permanently have a prefabricated lower object part on which a additively constructed upper object part is arranged. However, it is also possible to separate the prefabricated lower parts which are connected to the additively constructed upper object part after the construction process from the additively constructed upper object parts; in this case, the end product only consists of a additively constructed section. Three-dimensional components within the meaning of the invention are therefore, on the one hand, the aforementioned hybrid components and, on the other hand, the additively constructed components which, after the construction process, are separated from a lower part which is only connected to the upper part during the construction phase.

[0002] The upper parts of such components are produced by successively solidifying layers of a building material, particularly a powdered material that can be solidified by radiation, with solidification occurring at the points corresponding to the respective cross-section of the upper part. Known devices suitable for this purpose include a carrying device for supporting the object during the construction process with a height-adjustable support. Furthermore, a coating device is provided for applying the building material layer by layer to a construction surface or a previously formed layer. Furthermore, an irradiation device is provided for the targeted irradiation of the layers of the building material at the points corresponding to the cross-section of the object. This device is usually a laser, the beam of which is directed via a controllable scanner onto the points of the layer to be solidified.

[0003] In such a device (e.g. according to DE 195 11 772 A1), a plate-like body is further arranged on the upper side of the carrier, which in the cited prior art serves as a building plate, ie on the upper side of which the powder-like building material of the first layer is melted.

[0004] Further prior art is known from the documents DE 299 07 262 U1, DE 20 2009 000 825 U1, US 2002 / 0 104 973 A1 and EP 2 289 652 A1.

[0005] The invention is based on the object of designing a device with the features of the preamble of claim 1 in such a way that it can be easily provided with lower parts for the construction process, onto which upper parts can be generatively built. The lower parts are intended to be easily and quickly attached to the support, and their location on the support is clearly predetermined. This object is achieved by the characterizing features of claim 1. Advantageous further developments emerge from the subclaims.

[0006] The core of the invention is considered to be the design of the preferably plate-like body, which in the prior art serves as a building plate, as a form-fitting plug-in holder for at least one prefabricated lower part of an object to be constructed. In other words, this means that construction does not generally take place on the plate-like body, but only on object lower parts that are inserted into the body serving as a holder and have an exposed upper side for construction. For this purpose, the body has at least one recess whose shape and outer contour correspond to the cross-section of a prefabricated object lower part that is to be inserted into it and in which the inserted prefabricated object lower part can be fixed. The body will preferably be a plate-like body, whereby its upward-facing surface does not necessarily have to be flat, because construction does not generally take place on this surface.

[0007] When we talk in this context about fixing the lower parts of the object in the plug-in holder, we initially mean the precise positioning of the lower parts of the object in the cutout of the plug-in holder assigned to them, so that the respective lower part of the object is precisely positioned in the X and Y directions, i.e. in the plane of the plate. Such precise positioning - assuming a really good fit of the plug-in holder - is generally sufficient to complete a build. In most cases, forces that could pull an object lower part inserted in this way out of the recess of the plug-in holder during the build are either non-existent or at least extremely small.

[0008] A secure holding of the inserted object bases, including in the Z direction, can be achieved in various ways. According to the invention, this is achieved by generating a vacuum that acts on the object bases from below, virtually pulling them into their recess and securing them there. The fixation between the prefabricated object base and the plug-in holder can also be achieved using a detachable clamp connection. A clamp connection can also be used to compensate for a certain amount of existing play in the X and Y directions - if a precise fit between the contour of the object bases and the associated plug-in holder recess is to be dispensed with for cost or assembly reasons. This would mean that the object base is then subjected to laterally pressure within its associated recess and pressed towards one or more side walls of the associated recess.

[0009] Advantageously, a plate-like plug-in holder is provided with a plurality of recesses with at least partially different shapes and contours, into which different prefabricated object bases can be inserted. Advantageously, the plurality of recesses can be arranged substantially evenly distributed over the surface of the plug-in holder for assembly or thermal reasons during the construction process.

[0010] It is also possible to support the fixation between the prefabricated object parts and the plug-in holder by means of a detachable adhesive connection, i.e. to prevent the inserted object parts from working in the recess of the plug-in holder assigned to them or from migrating upwards during the construction process by means of a detachable adhesive.

[0011] One implementation of a clamping device can involve raising the temperature of the plug-in holder before inserting the object's lower part(s) to temporarily expand the recesses, then inserting the object's lower parts, and then cooling the plug-in holder again. This results in a very tight clamping connection across multiple flanks or walls within the recesses, so that the object's lower parts are held in place very precisely. However, it is also possible to design the plug-in holder as the upper part of a two-element body, which is attached to a lower part, which in turn is releasably connected to the device's support, e.g., by a clamping and / or centering device.This makes it possible to remove the two-element body, which is equipped with object lower parts onto which upper parts have already been generatively built, from the device by loosening the clamping and / or centering device and to insert it into another device for post-processing of the generatively built upper parts.

[0012] It is particularly advantageous if the lower part of the two-element, and thus two-layered body is also plate-like and also provided with recesses whose arrangement and shape correspond to the recesses in the upper part. This allows the use of relatively long object lower parts that extend through the upper part of the two-layered body and protrude into the initially congruent recesses of the lower parts. If the plates are then slightly shifted or clamped against each other, such a clamping process can fix a plurality of object lower parts in the plug-in holder.

[0013] Advantageously, the recesses are of different shapes, e.g., polygonal such as trapezoidal, triangular, star-shaped, octahedral, or similar, and / or partially rounded, e.g., crescent-shaped or semicircular, or form a combination of polygonal or partially circular shapes. Object bases of the corresponding shape can otherwise be "sorted" into the appropriate recesses of the plug-in holder using a key principle, which is particularly quick and easy.

[0014] To facilitate the coating process, the surfaces of the prefabricated object bases intended as the basis for the generative construction are arranged essentially in the same plane as the top of the plug-in holder.

[0015] The invention is explained in more detail using exemplary embodiments in the drawing figures. These show: Fig. 1 is a schematic perspective view of the main components of a device according to the invention; Fig. 2 a modified device with a double-layer plug-in holder; Fig. 3 is a schematic sectional view of a device with a double-layer plug-in holder; Fig. 4 is a schematic sectional view of a device with another double-layer plug-in holder; Fig. 5 a further embodiment of a double-layer plug-in holder with centering device; Fig. 6 a sub-part of the object in a further form; Fig. 7 an arrangement of several object sub-parts for joint processing and Fig. 8 further forms of object subdivisions, and Fig. 9 a design of the plug-in holder with plug-in modules.

[0016] First, reference is made to Figure 1. The device shown in Fig. 1 is only partially shown, is used to produce three-dimensional objects by successively solidifying layers of a powdered building material 1, which is stored in a dosing container 2 and can be layered by an application device 3 onto a base 4, which is attached to a carrier 5 in a build chamber 6 and, together with the carrier 5, is arranged so that its height can be adjusted in the build chamber 6. The application device 3 is designed in the manner of a coating blade 7, which can be moved in the direction of arrow 8 over the dosing containers 2 and can apply a thin layer of the building material to a corresponding base. To solidify this layer at the desired locations, an irradiation device 10, in particular a laser, is provided; a focused beam 11 of the laser is directed via a scanner device 12 onto the areas of the building material layer that correspond to the cross-section of the object to be built.

[0017] The preferably plate-like body 4 is designed as a form-fitting plug-in holder 30 for at least one prefabricated object base 31 of an object to be constructed and, for this purpose, has at least one recess 32 whose shape and outer contour correspond to the cross-section of a prefabricated object base 31 to be inserted into it. Figure 1 shows two object bases 31 in the shape of a sickle and in the shape of a trapezoidal body, which can be inserted from above into the corresponding recesses 32 assigned to them. The object bases 31 can be fixed in the recesses 32, which can be done in different ways.

[0018] A first possibility for fixing consists in providing such an exact fit between the recesses 32 and the contour of the object bases 31 that the object bases 31 experience a quasi-suction fit when inserted into the recesses 32, so that they can neither move in the plane of the plate nor is there a risk that they will be pulled upwards out of their recesses 32 during the machining process.

[0019] However, as provided according to the invention, it is also possible to fix the object lower parts 31 in their recesses 32 in another way, namely by generating a negative pressure which draws the inserted prefabricated object lower part 31 into the recess 32 of the plug-in holder 30 in the direction of the carrier 5 and thereby additionally fixes it in the Z direction.

[0020] Another possibility would be a droplet of adhesive with which the object base 31 can be fixed in its recess 32 of the plug-in holder 30, whereby the adhesive must be removable, for example by the application of heat or by means of an appropriate solvent.

[0021] A further possibility is to create a clamping effect between the plug-in holder 30 and the object bases 31. This can be achieved, for example, by heating the plug-in holder before inserting the object bases 31 into the recesses 32, so that the recesses 32 expand slightly and then cooling down with the object bases 31 inserted, so that the clamping is established as a result of the contraction in the area of ​​the recesses 32. The plug-in holder 30 can be designed as the upper part of a two-element or two-layer body; a lower part 33 of this two-layer body can be detachably and precisely connected to the carrier 5 by a clamping and / or centering device 40.

[0022] The lower part 33 of the body 4 can - just like the upper part - be plate-shaped and also be provided with recesses 32', the arrangement and shape of which correspond to the recesses 32 in the upper part, i.e., in the plug-in holder 30. The upper part and lower part 33 can be clamped laterally to one another in a parallel position; as a result, the prefabricated lower parts 31, which pass through the recesses 32 of the upper part and engage in the recesses 32' of the lower part 33, can additionally be fixed both in the Z direction and in the XY direction (at the plate level).

[0023] As in Fig. 1 and Fig. As shown in Figure 2, the recesses 32, 32' are polygonal, in particular star-shaped, triangular, or octahedral. They can also be additionally or separately rounded in sections and shaped like a crescent or semicircle. Important in this context is that the object's lower parts can be easily inserted into the designated slots in the plug-in holder using an easily understandable key / keyhole principle.

[0024] If the upward-facing surfaces of the inserted prefabricated object bases intended for the generative construction of the object(s) are arranged essentially in the same plane as the upper side of the plug-in holder, the coating process can be carried out in a simple manner and in a way that saves building materials.

[0025] The embodiment according to Fig. 2 largely corresponds to the example in Fig. 1, but for reasons of clarity, the irradiation device, namely the laser 10 and the scanner 12, are omitted. The embodiment according to Fig. 2 differs in that the plug-in holder 30 is applied to a lower part 33 and pre-fixed there, e.g., via a dowel pin 35. This allows parts 30 and 33 to be easily separated from each other. The recesses 32 not occupied during the construction process can be filled with construction material 1, which then, due to the underlying plate, namely the lower part 33, does not fall through to the support 5, thus saving construction material 1.

[0026] In the Fig. In the embodiment shown in Figure 4, the plug-in holder 30 is again pre-attached to the lower part 33 by a locating pin and is fixed, in particular, in the Z direction by a magnet arrangement 45, which pulls the plug-in holder 30—assuming it is made of a magnetizable material—against the lower part 33 and holds it there. The same applies to magnetic object lower parts 31.

[0027] In the Fig. In the embodiment shown in Figure 5, the plug-in holder 30 can be pushed onto a lower part 33, which does not necessarily have to be a flat plate, for which purpose a mutual dovetail guide 36 is provided, which can be fixed by grub screws or the like transversely to the pushing-on direction.

[0028] Fig. 6 shows a further embodiment of a prefabricated object base 31, which has a circumferential projection 34. The circumferential projection 34 can either have a shape corresponding to the shape of the object base 31, but it can also, for example, always have a circular or rectangular shape, regardless of the shape of the object base 31. The circumferential projection 34 can compensate for inaccuracies in the manufacture of the recesses 32. In particular, the circumferential projection 34 allows the recesses 32 to be slightly too large throughout, thus preventing frictional engagement between the object base 31 and the plug-in holder 30. The circumferential projection 34 then prevents the object base 31 from being inserted too deeply into the recess 32.

[0029] Fig. Figure 7 shows an arrangement of the object lower parts 31 that enables joint processing. For this purpose, several object lower parts 31 are arranged in the plug-in holder 30. A liquid film 37 is located between the plug-in holder 30 and the lower part 33. The plug-in holder 30 and the lower part 33 can be precisely aligned using one or more centering pins 38. As already explained for the object lower parts 31 and the recesses 32, the centering pins 38 can also be adapted to the recess in the lower part 33 such that a frictional connection is achieved. However, the centering pins 38 can also have a smaller circumference than the recesses, so that only positioning of the plug-in holder 30 on the lower part 33 is possible, but not a permanent connection. Of course, the centering pins 38 can also be fastened to the lower part 33, and the corresponding recesses are then located on the plug-in holder 30.Furthermore, it is also possible that part of the centering pins are arranged on the lower part 33 and another part on the plug-in holder 30.

[0030] The joint processing of the object parts 31 can be carried out, for example, by means of a grinding device 39, which is Fig. 7 is shown purely schematically. In order to make differently shaped object lower parts 31 accessible for joint processing, these can be designed in two parts, wherein the first section 41 and the second section 42 of the object lower part 31 are connected by a predetermined breaking point 43. On the right-hand side of the plug-in holder 30 there is a one-piece standard object lower part 31, at the height of which the adjustment of the two-part object lower parts 31 with the first section 41 and second section 42 takes place.

[0031] The provision of predetermined breaking points 43 is, of course, also possible if no joint processing of the object bases 31, for example, by means of the grinding device 39, is planned. Dividing the object bases 31 into two parts then enables the provision of standardized, i.e., identical, recesses 32, whereby the object bases 31 can thus be adapted, at least in terms of height, to the standardized recesses 32.

[0032] In a preferred embodiment, the predetermined breaking points 43 are arranged directly above or below a circumferential projection 34. In this case, the second section 42 is preferably also standardized or adapted to standardized recesses 32, so that the second section 42, the predetermined breaking point 43 and the circumferential projection 34 form a type of standard interface. The arrangement of the predetermined breaking point 43 is preferably above the circumferential projection 34, in particular if the course of the predetermined breaking point 43 does not run parallel to the surface of the plug-in holder 30. If one considers the middle object lower part 31 in Fig. 7, it is evident that with this design of the predetermined breaking point, the circumferential projection 34 must run below the predetermined breaking point 43, unless the circumferential projection 34 is to remain on the final object.

[0033] Fig. 8 shows a further design option for the object bases 31. In this embodiment, the predetermined breaking points 43 are located on second sections 42 such that, after inserting the object base 31 into the recess 32, they are arranged just above the plug-in holder 30. The second sections 42 can be standardized, but do not have to be. After the generative build-up of the third section 44 on the first section 41 and the removal of the excess build material 1 from the build chamber, the second sections 42 of the object bases 31 can then be separated simply by separating or cutting them off using a separating device or by simply breaking them off at the predetermined breaking points 43.

[0034] The following summarizes the sequence of a construction process in a device according to the invention: First, the plug-in holder 30 must be manufactured by providing a preferably standardized plate with recesses 32. This plate must be inserted into the build chamber.

[0035] To secure the object bases 31, the plug-in holder 30 can be heated. The object bases 31 are then inserted into the still-heated plug-in holder 30, with the object bases 31 automatically being clamped into the plug-in holder 30 upon cooling. Of course, the other mechanisms for clamping the object bases 31 described above are also possible.

[0036] After clamping, the surfaces of the object's lower parts 31 are jointly reworked to an adjusted and precise height. This rework can be performed by grinding or milling.

[0037] The plug-in holder 30 with the clamped object sub-parts 31 is then inserted into the device or the build chamber and fixed to the floor of the build chamber by means of a clamping system plug-in holder or another fixing device. During insertion, a security code attached to the plug-in holder 30 by means of a chip is read, for which purpose a corresponding read head is arranged on the floor of the build chamber. By checking the security code, it can be determined whether the plug-in holder 30 meets the specified requirements. The security code 30 can accordingly be used to identify the plug-in holder 30 or its properties. The security code can provide information about the number of recesses 32, their size, the height of the plug-in holder 30, or any other data relating to the plug-in holder 30, so that a security check can take place.

[0038] If the plug-in holder 30 is suitable for the intended construction process, the construction of the third section 44 onto the first section 41 can begin.

[0039] After assembly, the object bases 31 are divided at the predetermined breaking points 43 so that the finished objects can be removed.

[0040] Fig.9 shows a further embodiment of the plug-in holder 30. This is constructed from plug-in modules 46, with at least one plug-in module 46 having a recess 32. Not every plug-in module 46 must have such a recess; plug-in modules 46 without a recess 32 can also be provided, which serve merely to stabilize and position the other plug-in modules 46. The plug-in modules 46 are inserted into a type of receiving tray 47. Instead of the receiving tray 47, the plug-in modules 46 can also be plugged onto a lower part 33, with each plug-in module 46 being plugged into the lower part 33 by means of a fixing device such as a locating pin 35. This fixing device can also be provided in addition to the provision of a side wall.

[0041] Particularly in the design with plug-in modules 46, it is advantageous to be able to use a sensor device to detect the position of the recesses 32 or the object bases 31. Particularly advantageously, the sensor device can detect not only the position but also the orientation of non-rotationally symmetrical object bases. This can prevent incorrect solidification of the building material 1. In particular, it becomes possible either to adapt the building process to the position and orientation of the plug-in modules 46 or, in addition, to also detect whether the recesses 32 of the plug-in modules 46 have the correct shape. This is of course not limited to the design of the plug-in holder 30 as plug-in modules 46; this check using a sensor device can of course be carried out with any design of the plug-in holder 30.If the recesses 32 are aligned centrally symmetrically with respect to the center of the plug-in holder 30, they are always in the same position regardless of the rotation of the plug-in holder 30; only the shape of the recesses 32 then still needs to be checked.

[0042] The sensor device can be configured as a camera. After checking the plug-in mount 30, the camera must be removed from the process chamber, as the temperatures prevailing during object construction would damage the camera. Alternatively, other measuring devices designed to detect the position and / or shape of a recess 32 can also be used. LIST OF REFERENCE SYMBOLS 1 construction material 2 dosing containers 3 Application device 4 bodies 5 carriers 6 Construction chamber 7 Coating blade 8 Arrow direction 10 Irradiation facility 11 beam 12 Scanner setup 30 plug-in holder 31 Lower part of the object 32 recess 33 Lower part 34 circumferential projection 35 Dowel pin 36 dovetail guide 37 Liquid film 38 centering pins 39 Grinding device 40 clamping / centering device 41 first section 42 second section 43 Predetermined breaking point 44 third section 45 Magnet arrangement 46 plug-in module 47 Holder

Claims

[1] Device for producing three-dimensional components which, after the construction process, consist of a prefabricated lower part and an upper part of the object generatively built thereon, wherein the upper part of the object is produced by successive solidification of layers of a radiation-solidifiable construction material (1) at the locations corresponding to the respective cross-section of the upper part of the object, and the device comprises the following: - a carrying device for carrying the object during the construction process with a height-adjustable support (5), - an application device (3) for applying the building material (1) layer by layer onto a building surface or an already formed layer and - an irradiation device (10) for the targeted irradiation of the layers of the building material (1) at the locations corresponding to the cross-section of the object, wherein - at least one body (4) is arranged on an upper side of the carrier (5), characterized by , that - the body (4) is designed as a form-adapted plug-in holder (30) for at least one prefabricated object base (31) of an object to be constructed and - for this purpose, it has at least one recess (32) in which the inserted prefabricated object base can be fixed, -- wherein the at least one recess (32) is designed as an opening in the body (4), wherein the fixing of at least one inserted prefabricated object base (31) in the plug-in holder (30) is effected by generating a negative pressure which draws the inserted prefabricated object base (31) into the recess (32) of the plug-in holder in the direction of the carrier (5) and fixes it therein. [2] Device according to claim 1, characterized bythat a plurality of recesses (32) with at least partially different shapes and contours for the use of different prefabricated object bases (31) are arranged in the plate-like plug-in holder (30). [3] Device according to claim 1 or 2, characterized by that the plurality of recesses (32) are substantially uniformly distributed over the surface of the plug-in holder (30). [4] Device according to one of the preceding claims, characterized by that the fixation between the prefabricated object base (31) and the plug-in holder (30) is effected by a detachable adhesive connection. [5] Device according to one of the preceding claims, characterized by that the plug-in holder (30) is designed as the upper part of a two-element body (4) which is fastened to a lower part (33) which is detachably connected to the support (5) of the device by a clamping / centering device (40). [6] Device according to claim 5, characterized by that the lower part (33) of the body (4) is plate-like and is also provided with recesses (32') whose arrangement and shape corresponds to the recesses (32) in the upper part. [7] Device according to claims 5 or 6, characterized by that the upper part and the lower part (33) can be clamped laterally to one another in a parallel position and the prefabricated object lower parts (31) pass through the recesses (32) of the upper part and engage in recesses (32') of the lower part (33). [8] Device according to claims 5 to 7, characterized by that a fluid film is provided between the upper part and the lower part (33). [9] Device according to one of the preceding claims, characterized bythat the recesses (32, 32') are polygonal, in particular star-shaped, triangular or octahedral and / or rounded in sections, in particular sickle-shaped or semicircular. [10] Device according to one of claims 5 to 9, characterized by in that it comprises a plurality of plug-in holders (30) which in particular have identical connection elements for connection to the lower part (33) or the carrier (5) and which differ only in the number and / or shape of the recesses (32). [11] Device according to one of the preceding claims, characterized by in that it comprises an electronic reading unit which reads a data source arranged on the plug-in holder (30), the data source serving to identify the plug-in holder (30). [12] Device according to one of the preceding claims, characterized bythat it has at least one sensor device for detecting the position of the at least one prefabricated object base (31). [13] Device according to claim 12, characterized by that the sensor device is designed as a camera or infrared sensor.

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