Device for producing three-dimensional objects by successively solidifying layers of a building material

Abstract

Device for producing three-dimensional objects by successively solidifying layers of a build-up material (1), in particular a powder form, which can be solidified by means of electromagnetic radiation or particle radiation, at the locations corresponding to the respective cross-section of the object, comprising a carrying device for carrying the object with a height-adjustable support (5), an application device (3) for applying the material, and an irradiation device for irradiating the applied layers of the material at the locations corresponding to the respective cross-section of the object, wherein a detachably attached base is provided on the support (5), wherein the base (4) is designed with at least two elements and has a lower, preferably plate-like body (15),which can be connected to the carrier (5) via a clamping / centering device (16) arranged on its underside and on which a top part (14), in particular plate-like, is detachably attached, characterized in that the top part (14) is fixed without screws by at least one plug-in projection (18, 45) in the XY plate plane on the bottom part (15) and a force-fit and / or a screwless positive-lock connection is effective between the top part (14) and the bottom part (15) in the Z direction and / or the fixing between the top part (14) and the bottom part (15) in the Z direction is effected by a suction connection, . wherein the lower part (15) engages with the underside of the upper part (14) by at least one positive locking projection, wherein the form-fitting projection is dovetail-shaped or has some other thickening and engages in a correspondingly shaped undercut of a counter-recess in the upper side of the lower part (15).

Description

[0001] The invention relates to a device for producing three-dimensional objects by successively solidifying layers of a particularly powdery building material by electromagnetic radiation or particle radiation, wherein the device has, among other things, a carrying device for carrying the object with a height-adjustable support, furthermore an application device is provided with which the building material can be layered and furthermore an irradiation device is provided for irradiating the applied layers of the material at the locations corresponding to the respective cross-section of the object.

[0002] Such a device is known from DE 195 11 772 A1. In this known device, the first powder layer is not solidified on the carrier, which is an integral part of the device, but rather on a base arranged on the carrier and removably attached in the form of a construction plate, which can be removed from the device together with the produced three-dimensional object after completion of the construction process.

[0003] Further devices of this type are known from US 2005 / 0 173 855 A1, US 5 939 008 A, DE 199 39 616 A1 and DE 199 18 613 A1.

[0004] The invention is based on the object of designing a device with the features of the preamble of claim 1 such that a finished component, including the support, can be quickly and easily removed from the device, can be reproducibly and accurately reinserted into the device or a similar processing device, for example, to perform further processing steps on the object, and the support is at least partially reusable. This object is achieved by the characterizing features; advantageous further developments emerge from the subclaims.

[0005] The invention is defined by the subject matter of the appended claims, which are to be interpreted with reference to the description and the drawings.

[0006] The core of the invention is considered to be the design of the two-layer base, which consists of an upper part and a lower part, without screw connections, so that the upper part can be changed quickly after a construction process has been carried out, if necessary without the aid of tools. For this purpose, at least one plug-in projection, e.g. a dowel pin, is provided which fixes the upper part in the XY plane, i.e. in the plate plane, relative to the lower part. Fixing in the Z direction can be achieved either by a screw-free form-fitting connection such as a clamp or the like, or by adhesion. For this purpose, it is sufficient to put a drop of oil, for example, on the upper side of the lower part; the upper part will then suck itself onto the lower part with its underside, which is usually sufficient for adequate fixation in the Z direction. Such a suction connection by adhesion can be released without the aid of tools.The same applies to a drop of glue, the adhesive strength of which should be such that the upper and lower parts can be pulled apart manually.

[0007] It is within the scope of the invention that both the lower part and the upper part of the base are formed from two plate-like bodies, in other words the base is designed as a "two-layer" or "two-ply". Due to the two-layer design, the lower part of the base, which is provided with a projection of the clamping / centering device, can be used multiple times; for a new construction process, a new upper part only needs to be plugged or pushed on. The upper and lower parts must be connected to one another in such a way that, on the one hand, the upper part assumes a precisely predetermined position after being placed on the lower part and, on the other hand, does not change its position relative to the lower part during the coating or construction process. Dowel pins, which act between the upper and lower parts, ensure that the precise position between the upper and lower parts is maintained.

[0008] In principle, it is also possible to hold the upper part in the Z direction by suction on the lower part by the effect of a negative pressure, whereby the lower part can be provided with at least one suction opening which is covered by a surface of the upper part and by means of which suction opening a negative pressure can be generated.

[0009] It is also within the scope of the invention to fix the upper part in the Z-direction on the lower part by means of magnetic force, although the use of magnetic powder materials can then be problematic.

[0010] The outer shape or contour of the upper and lower parts are adapted to the inner contour of a build chamber, in which the support device with the carrier is arranged in a height-adjustable manner. The inner wall of the build chamber then secures both the lower and upper parts against twisting within the build chamber.

[0011] It is also within the scope of the invention to fix several upper parts on a lower part provided with a clamping device, which can be particularly advantageous if several small objects are to be manufactured in the device simultaneously during a construction process.

[0012] The lower part can also engage the underside of the upper part with a plug-in projection similar to a form-fitting projection, or conversely, the upper part can engage the upper side of the lower part with at least one form-fitting projection. Such a plug-in form-fitting projection can, for example, be dovetail-shaped, T-shaped, or have some other thickening, so that the upper and lower parts can be slid onto one another, so that both parts are secured together in the Z direction and prevent twisting without screws.

[0013] The invention is explained in more detail using advantageous embodiments in the drawing figures. These show: Fig. 1: a schematic perspective view of a part of the device for producing three-dimensional objects with a two-element base; Fig. 2: an exploded view of a two-layer base; Fig. 3: a schematic sectional view of a two-layer base, mounted on a height-adjustable support with different form-fitting connections; Fig. 4: a schematic sectional view of a two-layer base with vacuum fixation between the upper and lower parts; Fig. 5: a schematic sectional view with magnetic fixation between upper and lower parts; Fig. 6: a schematic perspective view of a lower part provided with dovetail-like projections which engage in corresponding shaped grooves of the upper part.

[0014] 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 of a build chamber 6 and, together with the carrier 5, is arranged in the build chamber 6 so that its height can be adjusted. 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 chamber 2 and, in doing so, applies a thin layer of the building material to the surface 9 of the base 4. This thin layer is solidified by an irradiation device 10, for which purpose a focused beam 11, in particular a laser beam, is directed via a scanner device 12 onto the building material layer at the locations that correspond to the cross-section of the object to be built.

[0015] The base 4 is detachably attached to the support 5 of the device.

[0016] The base 4 is constructed in two elements and consists of a lower body 15 and a plate-like upper part 14, which is provided with the surface 9 on which the object is built. A clamping / centering device 16 is provided on the underside of the lower body 14, which engages in a recess 17 of the carrier 5 and can be fixed there. The upper part 14 is releasably attached to the lower part 15 in such a way that it does not change its position relative to the lower part 15 during the construction process.

[0017] In the Fig. 1 and Fig. In the embodiment shown in Figure 2, the upper part 14 is fixed to the lower part 15 by at least one locating pin 18, wherein the locating pin 18 engages in a recess 19 in the underside of the upper part 14. In the Z direction, ie in a direction substantially perpendicular to the surface 9, a force-locking or form-locking connection is advantageously additionally effective, which ensures that the upper part 14 does not lift off during the construction process, which could be caused by the action of external forces.

[0018] There are different ways to fix the upper and lower parts in the Z-direction. If the upper part 14 and the lower part 15 are plate-shaped, as shown in Fig. 1, Fig. 2 and Fig. 3, it is possible to fix the underside of the upper part 14 to the upper side of the lower part 15, e.g., by adhesion, such as a drop of oil, so that a suction connection is established. However, it is also possible to attach the upper part 14 to the lower part 15 using a removable adhesive.

[0019] Furthermore, it is possible to fix the lower part 15 and the upper part 14 by means of form-locking elements 26 in their edge area. Fig. Figure 3, for example, shows a clamping band 25 that secures the parts placed on top of each other at the edges. For this purpose, circumferential grooves can be provided in the edge area, which can interact with the clamping band 25.

[0020] Furthermore, Fig. 3 shows a further, separate example of a fixation, a bayonet-like form-locking element 26 which can engage in an undercut recess 27 and fixes the parts 14 and 15 to one another in the Z direction by twisting in the manner of a bayonet.

[0021] In Fig. Figure 4 shows another possibility for fixing in the Z-direction, namely a suction opening 30, which is connected to a vacuum pump 32 via a vacuum hose 31 and applies suction to an area of ​​the upper part 14, thus achieving the desired fixing in the Z-direction. The two plate-like upper and lower parts 14, 15 are secured against rotation by the locating pin 18.

[0022] Fig. Figure 5 shows another possibility for fixing in the Z-direction, namely by magnetic action. Upper parts of the building panels can be made of steel, i.e., a magnetic material. Fixing in the Z-direction can be achieved by arranging at least one magnet 40, which can be embedded in the lower part 15.

[0023] In an alternative embodiment according to Fig.6, the lower part 15, which in this case is not plate-like but U-shaped, has dovetail-like projections 45 that engage in dovetail grooves in the underside of the upper part 14. The upper part 14 can be pushed onto the lower part 15 with the dovetail projections before assembly by the clamping / centering device 16 on the support 5. Using a grub screw or the like, the dovetail connections can then be fixed in such a way that even sliding the upper part 14 and the lower part 15 apart is no longer possible. Dovetail projections 45 and corresponding groove-like recesses 46 can, of course, also be arranged on plate-like lower parts 15. It is equally possible to arrange the dovetail projections 45 on the upper part 14 and the corresponding groove-like recesses 46 in the lower part 15.

Claims

[1] Device for producing three-dimensional objects by successively solidifying layers of a building material (1), in particular in powder form, which can be solidified by means of electromagnetic radiation or particle radiation, at the locations corresponding to the respective cross-section of the object, with a carrying device for carrying the object with a height-adjustable carrier (5), an application device (3) for applying the material and an irradiation device for irradiating the applied layers of the material at the locations corresponding to the respective cross-section of the object, wherein a detachably fastened base is provided on the carrier (5), wherein the base (4) is designed in at least two elements and has a lower, preferably plate-like body (15),which can be connected to the support (5) via a clamping / centering device (16) arranged on its underside and on which a particularly plate-like upper part (14) is detachably fastened, , characterized by that the upper part (14) is fixed to the lower part (15) without screwing by at least one plug-in projection (18, 45) in the XY plate plane and a force-locking and / or a screw-free form-locking connection is effective between the upper part (14) and the lower part (15) in the Z direction and / or the fixing between the upper part (14) and the lower part (15) in the Z direction is effected by a suction connection, wherein the lower part (15) engages with at least one positive-locking projection into the underside of the upper part (14), wherein the form-fitting projection is provided in a dovetail shape or with another thickening and engages in a correspondingly shaped undercut of a counter-recess in the upper side of the lower part (15). [2] Device according to one of the preceding claims, characterized by that the underside of the upper part (14) is fixed to the top side of the lower part (15) by a removable adhesive. [3] Device according to one of the preceding claims, characterized by that the lower part (15) and the upper part (14) are fixed to one another in their edge region by clamp-like form-locking elements (26). [4] Device according to claim 3, characterized by that the edge regions of the upper part (14) and the lower part (15) are fastened to one another by a tensioning band which encompasses both parts at least in part. [5] Device according to one of the preceding claims, characterized by that the lower part (15) is provided with at least one suction opening (30) through which the upper part (14) is fixed by suction against the surface of the lower part (15). [6] Device according to one of the preceding claims, characterized bythat the fixing of the upper part (14) to the lower part (15) is effected by magnetic force. [7] Device according to one of the preceding claims, characterized by that the shape of the upper part (14) and / or the lower part (15) is adapted to the inner contour of a construction chamber in which the carrying device with the carrier (5) is arranged. [8] Device according to one of the preceding claims, characterized by that several upper parts (14) are arranged on a lower part (15). [9] Device according to claim 8, characterized by that the total area of ​​the plurality of upper parts (14) substantially corresponds to the area of ​​the lower part (15). [10] Device according to one of the preceding claims 8 or 9, characterized by that the shape of the upper parts (14) is adapted to the contour of the three-dimensional object to be built on them in the transition area between the upper part (14) and the generatively constructed section of the object. [11] Device according to one of the preceding claims, characterized by that in the side wall areas of the upper and / or lower part (14, 15) groove-like undercuts are arranged at least in some areas, into which clamp-like edge-side fixing elements engage.

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