WO2017008892A1

WO2017008892A1 - Device and method for producing a three-dimensional object

Info

Publication number: WO2017008892A1
Application number: PCT/EP2016/001154
Authority: WO
Inventors: Thomas Mattes
Original assignee: Eos Gmbh Electro Optical Systems
Priority date: 2015-07-10
Filing date: 2016-07-06
Publication date: 2017-01-19
Also published as: DE102015213008A1

Abstract

A device (1) for producing a three-dimensional object (2) by selective layered compaction of buildup material (13) includes a process chamber (3) with a chamber wall (4) and a first process module (14), which can be moved over a building zone (10) within the process chamber (3) in a direction of movement (B), is suitable for carrying out a process required for producing a three-dimensional object (2) and has at least one drive shaft (30) extending transversely in relation to the direction of movement (B). The chamber wall (4) of the process chamber (3) has an elongated clearance (31), through which the drive shaft (30) is led and along the longitudinal direction of which the drive shaft (30) can be moved to move the process module (13) in the direction of movement. At least one flexible sealing element (41) is provided substantially over the entire length of the clearance (31) in such a way that it seals off an intermediate space between the two longitudinal sides of the clearance (31) and/or between a longitudinal side of the clearance (31) and the side of the drive shaft (30) that is facing this longitudinal side. At least one closure device (42) is arranged in such a way that it exerts a force on the sealing element (41), along the longitudinal direction of the clearance (31), to seal off the intermediate space between the two longitudinal sides of the clearance (31) and/or between a longitudinal side of the clearance (31) and the side of the drive shaft (30) that is facing this longitudinal side.

Description

Apparatus and method for manufacturing

a three-dimensional object

The present invention relates to an apparatus and a method for producing a three-dimensional object by selective layer-by-layer solidification of building material.

Methods and devices of this type are used, for example, in rapid prototyping, rapid tooling or additive manufacturing. An example of such a method is known as "selective laser sintering or laser melting." In this case, a thin layer of powdery build material is repeatedly applied and the build material in each layer is selectively solidified by selective irradiation with a laser beam.

European Patent EP 0 734 842 A1 discloses a device with a laser and an associated scanning device, by means of which a solidification of powder takes place at locations corresponding to the cross section of the object in a process chamber. A horizontally movable Coating device applies the powder layers to be consolidated on a building platform or an already solidified powder layer.

In particular, at high process temperatures, it is desirable to arrange the drive for the coater device outside the process chamber. For this purpose, the chamber wall can have a recess through which an axis connecting the drive with the coater device can be passed and along which it can be displaced: this recess must be sealed in order to reduce or even completely eliminate gas exchange between the interior and exterior of the process chamber to prevent.

A seal for a recess of a chamber wall is known from the European patent EP 1037739 Bl, wherein a roller blind an engagement recess through which the building platform supporting support arms are passed, sealed in a powder-tight manner. In particular, in the event that other modules such. an exposure device are arranged to be movable in the same direction, changing their distance from each other, the sealing of the recess 31 by means of a roller blind proves to be impractical, since the various modules must be performed in this seal by different recesses.

The object of the present invention is to provide an alternative, preferably an improved, apparatus and a corresponding method for producing a three-dimensional object. In particular, an improved sealing of the recess, through which the drive axis of a process module is passed, is to be provided here, so that several drive axles can be moved in the same recess.

The object is achieved by a device according to claim 1 and a method according to claim 15. Further developments of the invention are specified in the dependent claims. The developments or embodiments mentioned in the subclaims and the description below relating to the device can also further develop the method according to the invention or vice versa.

The inventive device for manufacturing a three-dimensional object by selectively layerwise solidification of the building material contains a process chamber with a chamber wall and at least one inside the process chamber in a shaft direction through a Baufeld movable first process module suitable for performing ^'a required for producing a three-dimensional object process is and has at least one transverse to the direction of movement extending drive axle. The chamber wall of the process chamber has an elongate recess through which the at least one drive axle is guided and along the longitudinal direction of which the at least one drive axle is movable for moving the at least one process module in the direction of movement. At least one flexible sealing element is mounted substantially over the entire length of the recess so that the sealing element has a gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side facing the at least one drive axle and / or between two seals sides facing each other by two in the transverse direction of the recess staggered drive axles. At least one closure device is arranged so that it along the longitudinal direction of the recess on the at least one sealing element, a force in the sealing of the gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side facing side of the at least one Drive axis and / or between two mutually facing sides of two in the transverse direction of the recess offset from each other drive axes serving direction exerts.

The closure device can be designed as an artifact that is separate from the sealing element (even if it may be tightly connected thereto); However, closure device and sealing element can also be realized integrated, namely in particular when the sealing element itself is able to exert a force in the effective direction as described in the paragraph above.

As the "drive axle" will be indirectly moved by the actuator in particular understood a mechanical Comp ^¬ component which mechanically connects, directly or indirectly an actuator (here outside the process chamber) with the process module so that this process module oriented in the process chamber along an axial course of the drive axle With regard to a coating module as a process module, one commonly speaks of a "coating arm" instead of a drive axis. Analogously, for example, a drive axis for an exposure module could be referred to as an "exposure arm".

As a result, even if the drive axis is moved along the recess, a good seal of the space in which the drive of the process module is located, from the Process chamber ensured. With this arrangement, a good seal is also possible if two or more drive axles are moved one behind the other along the recess.

Preferably, a fixed flexible sealing element is attached to each of the two longitudinal sides of the recess such that the two sealing elements jointly seal a gap between the two longitudinal sides of the recess and / or between the two longitudinal sides of the recess and the side of the at least one drive axis facing this longitudinal side, and a closure device is arranged so that along the longitudinal direction of the recess on at least one sealing element, preferably both sealing elements, a force in the space between the two longitudinal sides of the recess and / or between one or both longitudinal sides of the recess and the longitudinal side o- the longitudinal sides facing side or sides of the at least one drive axis serving direction exerts.

By sealing the recess on both sides against the drive axle an even better seal is achieved.

Preferably, two drive axes are arranged offset in the transverse direction of the recess against each other, parallel to the two longitudinal sides of the recess, a flexible sealing element between the two drive axles is mounted so that there is a gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side facing one of the two drive axles and / or seals between the two facing side of the two drive axles, and the closure device is arranged so that they along the longitudinal direction the recess on at least one sealing element, preferably both sealing elements, a force in the side of one of the two drive axles and / or between the two facing each other for sealing the gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side Side of the two drive axes serving direction exerts.

As a result, even if two staggered Antriebsachsen- ent. long the recess are moved, a good seal of the space in which the drive of the process module is located, guaranteed by the process chamber even if both drive axles are in the same place, in the longitudinal direction of the recess.

Preferably, the drive axis in the plane of the chamber wall, through which it is passed, an elongated, preferably ship-shaped cross-section, in a particularly preferred manner with a double S-shaped outer contour, whose longitudinal direction extends in the longitudinal direction of the recess.

As a result, the leaks occurring at the locations where the drive shaft separates or rejoins the sealing elements can be reduced and deformation of the sealing elements can be minimized, which increases their service life.

Preferably, at least one sealing element is formed as a lip or as a bellows and / or of a rubber-elastic fluoroelastomer and / or of (in particular glass) fiber-reinforced PTFE film and / or of Teflon-reinforced fabric. The lip and bellows are sturdy and easy-to-handle replacement parts, and the material can be selected based on the application and the prevailing environmental conditions, with fluoroelastomer being less expensive and (glass) fiber reinforced PTFE film or Teflon reinforced fabric more resistant and durable.

The closure device preferably contains a pretensioned spring plate which is attached to at least one sealing element and which is designed in particular as a spring comb.

The force for reclosing the seal is applied by the spring plate or spring comb and is thus largely independent of the material used and the shape of the sealing element.

The closure device preferably contains a magnetic strip attached to at least one sealing element, which in a further preferred manner contains a thin ferromagnetic strip and / or a flexible retaining strip with inserted magnets, in particular neodymium magnets.

As a result, a space-saving embodiment of a closure device is provided. In particular, neodymium magnets ensure a sufficiently large magnetic holding force.

Preferably, the device includes an outer gate and / or a counter-guide, which is arranged displaceably with the drive axle so that they by mechanical guidance

Supports closing action of the closure device and / or the sealing element. The outside or opposite scenery is For this purpose, preferably together with the drive axle movable, in particular coupled in terms of motion technology with her.

This can u.a. a better sealing of the sealing elements against the drive axle and a better sealing of the entire recess after passing through the drive axle or a smoother running in the movement of the drive axle can be achieved.

Preferably, the drive axle and / or the outer slide and / or the counter slide are formed as a hollow body and / or in several parts.

The formation as a hollow body, for example, reduces the heat flow out of the process chamber, so that i.a. the thermal insulation effect is improved. A multi-part design allows, for example, a better mountability in narrow recesses of the process chamber wall.

Preferably, the counter-raceway is substantially shaped as a counter-shape to the at least one sealing element, preferably to all sealing elements, and arranged and / or mounted so that it reduces movement of the sealing element away from the drive axle, preferably substantially prevented and upon movement of the drive axle / or that it returns the sealing element in the direction of movement behind the drive axle to its original position.

As a result, inter alia, an even better sealing of the sealing elements against the drive axle and a better sealing of the entire recess after passing through the drive axle The device preferably contains at least one second process module that can be moved in the direction of movement and that can be driven together with the first process module by the at least one drive axle or by a further drive axle. The first and / or the second process module (s) may in particular be selected from a coating module which is suitable for applying a layer of the building material to a construction field, and / or an exposure module which is used to solidify the construction material applied to the construction field - is suitable.

This allows, for example, a space-saving and effective use of multiple process modules and their drive through a common recess of the chamber wall through what the efficiency and cost-effectiveness of. Device boosts.

The method according to the invention for producing a three-dimensional object by selective layer-by-layer solidification of building material is carried out in a device comprising a process chamber with a chamber wall and a process module movable in a movement direction over a building field within the process chamber, which are required for performing a three-dimensional object Process is suitable. To move the process module in the direction of movement, a drive axis extending transversely to the direction of movement, which is passed through an elongate recess in the chamber wall of the process chamber, is moved along the elongated recess. During movement of the drive axle along the elongated recess, at least one fixed flexible seal member seals substantially over the entire length of the recess is, a gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side facing side of the at least one drive axle and / or between two facing sides of two spaced apart in the transverse direction of the recess drive axles. A closure device exerts along the longitudinal direction of the recess on the at least one sealing element a force in the side of the at least one drive axle and / or between two sides facing the gap between the two longitudinal sides of the recess and / or between a longitudinal side of the recess and the longitudinal side facing sides of two in the transverse direction of the recess spaced-apart drive axes serving direction.

In this method, even when the drive shaft is moved along the recess, a good seal of the space in which the drive of the process module is provided by the process chamber. In this method, a good seal is also possible when two or more drive axles are moved one behind the other along the: recess.

Other features and advantages of the invention will become apparent from the description of embodiments with reference to the accompanying ^' drawings.

Fig. 1 is a schematic, partially in section

View of an embodiment of a device according to the invention for the layered production of a three-dimensional object. Figs. 2a to 2d are schematic sectional views of a drive shaft shown in Fig. 1.

3 is a schematic perspective view of a seal according to a first embodiment of the present invention.

4 is a schematic perspective view of a seal according to a second embodiment of the present invention.

Figs. 5a to 5c are schematic sectional views of various

Arrangement forms of sealing elements.

Fig. 6 is a schematic perspective view of a. Sealing according to a first modification of the second embodiment.

Fig. 7 is a schematic perspective view of a seal according to a second modification of the second imple mentation form.

8 is a schematic perspective view of a seal according to a third modification of the second embodiment.

Fig. 9 is a schematic sectional view of a seal according to a fourth modification of the second embodiment. 10 is a schematic sectional view of a seal according to a fifth modification of the second embodiment.

Fig. 11 is a schematic sectional view of a seal according to a third embodiment of the present invention.

Hereinafter, an apparatus according to a first embodiment of the present invention will be described with reference to FIGS. The apparatus shown in FIG. 1 is a laser sintering or laser melting apparatus 1. For constructing an object 2, it contains a process chamber 3 with a chamber wall 4.

In the process chamber 3, an upwardly open container 5 is arranged with a wall 6. In the container 5, a movable in a vertical direction V carrier 7 is arranged, on which a base plate 8 is mounted, which closes the container 5 down and thus forms its bottom. The base plate 8 may be a plate formed separately from the carrier 7, which is fixed to the carrier 7, or it may be integrally formed with the carrier 7. Depending on the powder and process used, a construction platform 9 can still be mounted on the base plate 8, on which the object 2 is built up. The object 2 can also be built on the base plate 8 itself, which then serves as Bauplattform-. In Fig. 1, the object 2 to be formed in the container 5 on the building platform 9 below an operating plane 10 defined by the upper edge of the container 5 is shown in an intermediate state with several solidified layers surrounded by building material 11 which has remained unconsolidated. The laser sintering device 1 further comprises a storage container 12 for a building material 13 which can be solidified by electromagnetic radiation and a coating module 14 movable in a horizontal direction H for applying the building material 13 to the working plane 10 the wall 4 of the process chamber 3 is provided. The coating module 14 is connected to the drive by means of a drive shaft 30, which in FIG. 1 runs perpendicular to the drawing direction. In this case, the drive shaft 30 is passed through an elongated recess 31 (shown by a dashed line) in the wall 4, along which the drive axle is movable.

The laser sintering device 1 further comprises an exposure device 20 with a laser 21 which generates a laser beam 22 which is deflected by a deflection device 23 and by a focusing device 24 via a coupling window 25 which is arranged in the top of the wall 4 of the process chamber 3, on the Working level 10 is focused.

Furthermore, the laser sintering device 1 includes a control unit 29, via which the individual components of the device 1 are controlled in a coordinated manner for carrying out the building process. The control unit may include a CPU whose operation is controlled by a computer program (software). The computer program can be stored separately from the device on a storage medium, from which it can be loaded into the device, in particular into the control unit. In operation, the carrier 7 is lowered by a ^'level for applying a first layer of powder corresponding to the desired layer thickness. By moving the coater 14 over the working plane 10, a layer of the powdery building material 13 is then applied. The application takes place at least over the entire cross section of the object 2 to be produced, preferably over the entire construction field, ie the region of the working plane 10 which lies within the upper opening of the container 5. Subsequently, the cross-section of the object 2 to be produced is scanned by the laser beam 22, so that the pulverulent build-up material 13 is solidified at the locations which correspond to the cross section of the object 2 to be produced. These steps are repeated until the object 2 is completed and the process chamber 3 can be removed.

For moving the coater 14 over the working plane 10, the drive shaft 30 is moved by the drive along the longitudinal direction of the recess 31 in the chamber wall 4. The recess 31 is provided with a seal (not shown in FIG. 1 - see subsequent figures) to reduce gas exchange between the inside and outside of the process chamber 3 as far as possible. or even completely prevent. When moving in a direction of movement B along the longitudinal direction of the recess 31, the drive shaft 30 must open the seal, and behind it, the seal must close again. In order to facilitate this, the drive shaft 30, at least in the region of the recess 31, has an oblong cross-section, the longitudinal direction of which points in the direction of movement B. FIG. 2 shows schematic examples of cross sections of the drive axle 30. In the simplest case, the cross section of the drive axle is elliptical or oval, as shown in FIG. 2a. Of the The radius of curvature is greatest in the center M of the profile in the direction of movement and lowest at the front and rear edge K in the direction of movement. But to open and close the seal as possible a sharp edge K at the opening or closing side of the drive shaft 30 is advantageous. Fig. 2b shows an axis cross-section in the form of a "boat", which is not rounded at its front and rear edge, but at an angle up, which is preferably as acute as possible. Even lower

Edge angles can be achieved with the variant shown in FIG. 2c. Here, the cross section has a double S-shaped outer contour, ie, not only the radius of curvature changes between an edge K and the center M of the profile, but also the direction of curvature in the turning points W (convex in the middle, concave on the outside). The tangent of the outer contour is in the edges preferably parallel to the longitudinal direction of the cross section, so that there are very sharp edges. Thereby . Be leaks at the edges in the process of the drive axle through the seal kept as small as possible or completely reduced. The outer contour is preferably formed with the largest possible radii of curvature, so that a smooth profile profile is formed, on which the seal can slide past as well as possible. The variants shown in Fig. 2a to 2c are symmetrical to its longitudinal axis, depending on the application, the cross section may also be asymmetrical. FIG. 2d shows a variant in which an outer contour of the profile is formed linearly parallel to the direction of movement B. FIG. Further modifications are possible. While the cross sections of the drive axle 30 are shown solidly in FIG. 2, the drive axle 30 can preferably also be formed as a hollow body. As a result, the heat transfer from the process chamber 3 for driving the coating module 14 is reduced and thus a good thermal insulation effect is achieved. In addition, the drive shaft 30 may also be wholly or partially made of a thermally insulating material. The drive shaft 30 is also preferably designed in several parts, which allows a better mountability of the drive shaft 30 in narrow recesses 31 of the process chamber 4.

Fig. 3 shows a schematic perspective view of a seal 40, as used in the present embodiment. On each of the two longitudinal sides of the recess 31, a sealing lip 41 is arranged as a sealing element. The sealing lips 41 are designed as flexible sealing lips 41 and formed of a heat-resistant rubber-elastic material, e.g. a fluoroelastomer such as Viton.

The two sealing lips 41 are slightly bent and lie on each other, whereby they seal the space between the two longitudinal sides of the recess 31 when the drive shaft 30 is not located between the sealing lips 41. When the drive axle 30 passes between the sealing lips 41, the spaces between each longitudinal side of the recess 31 and the side of the drive shaft 30 facing the latter are likewise sealed by the sealing lips 41. The front in the direction of movement B edge of the drive axle separates the sealing lips 41 from each other, at the rear edge they close again. In a rubber-elastic material, the sealing of the intermediate spaces between the longitudinal sides of the recess 31 and / or between a longitudinal side and the drive axle 30 is achieved by the elastic restoring forces of the deformed sealing lips 41. With such large cross sections, as they must be used in the present case, this elastic restoring force may be insufficient. In addition, it tends to diminish over time in the temperatures prevailing in the process chamber of a laser sintering device.

Therefore, according to the present invention, a closure device is provided separate from the sealing element formed as a sealing lip 41, which generates a force transverse to the longitudinal axis of the recess 31 on the sealing lips 41. This force causes closure of the sealing lips 41 and is substantially independent of the sealing lip material used.

In the present embodiment, the closure means is formed by disposing, in addition to the sealing lip 41 on each of the two longitudinal sides of the recess 31, a biased spring plate which, along the longitudinal direction of the recess, adds an extra force to the lips in the space between them both longitudinal sides of the recess or between a longitudinal side of the recess and the side facing this longitudinal side of the drive axle. As is shown in FIG. 3, the spring metal sheet can be embodied as a spring steel comb 42, the sheet thickness, the comb tooth width and the comb gap width being selected according to a desired closing force. As a result, the closure effect of the seal 40 no longer depends only on the inherent rigidity of the sealing lips 41, but additionally or alone by the closure device which is independent of the properties of the sealing material. Therefore, it is not even required that the sealing lips 41 be formed of a rubber-elastic material. They may also be formed, for example, from glass fiber reinforced PTFE film or Teflon reinforced fabric, which have a higher wear resistance, whereby the life of the seal 40 can be increased.

The seal 40 with closure device described makes it possible, during the process of the drive shaft 30 along the recess 31, to reliably seal the process chamber 3 with respect to the space in which the drive of the drive shaft 30 is arranged. The drive axle 30 opens with its front edge K the seal by separating the lips from each other. The applied by the .Federblechkamm 42 on the sealing lips 41 force causes the gap between the longitudinal sides of the recess 31 and the drive shaft 30 is reliably sealed and that close the sealing lips 41 behind the drive shaft 30 again reliably. Thus, the space in which the drive of the drive shaft 30 is arranged can be effectively protected by the process conditions prevailing in the process chamber, in particular by the temperature prevailing there.

With this construction of the seal 40, two or more drive axles can also be passed through the same recess 31 in succession and moved along their longitudinal direction, without their distances from each other remaining the same. 4 shows a schematic perspective view of a seal 50 according to a second embodiment.

On each of the two longitudinal sides of the recess 31 in the chamber wall 4, a bellows 51 is arranged as a sealing element. The two bellows 51 seal in the absence of the drive shaft 30, the recess 31. In the presence of the drive axle 30, the intermediate space between a longitudinal side of the recess 31 and the side of the drive shaft 30 facing it is also sealed by the bellows 51 provided on this longitudinal side. Since the deformation of the bellows 51 takes place over a plurality of layers of the bellows 51, the total possible deformation of the sealing element is large with simultaneously small deformation of the individual layers, which increases the life of the sealing element. For example, the bellows may be formed of the same materials as indicated in the first embodiment of the sealing lips 41.

In the present embodiment, two deformable magnetic strips 52 are arranged at the mutually facing ends of the two bellows 51 as separate from the closure device formed as a sealing element. Such flexible magnetic strips are formed, for example, from a polymer matrix with embedded magnetic chips. The closing force between the two bellows is achieved here by the magnetic attraction between the magnetic strips.

During the process of the drive shaft 30 along the recess 31 opens drive shaft 30 with its front edge K the Sealing 50 by separating the bellows 51 and the magnetic strips 52 from each other. Behind the drive axle 30, the bellows 51 are interconnected again by their own elasticity and by the magnetic strips 52. Thus, also by the second embodiment, the space in which the drive of the drive shaft 30 is arranged can be effectively protected from the process conditions prevailing in the process chamber.

5 shows diagrammatically various arrangements of bellows 51.

Fig. 5a corresponds to the example shown in Fig. 4, in which a single drive shaft 30 is guided approximately centrally through the recess 31 in the chamber wall and on both sides of the drive shaft 30 each have a bellows 51 is arranged to seal the recess.

Alternatively, the drive shaft 30 as shown in Fig. 5b also on the underside (or analog top side - not shown) of the recess 31 may be arranged so that only a bellows 51 is required for sealing. Preferably, the drive shaft 31 is flat in this case on its underside as shown in Fig. 2d.

However, it is also possible for two or more drive shafts 30, which are offset in relation to each other in the transverse direction of the recess 31, to be arranged so as to be movable independently of one another along the longitudinal direction of the recess 31. If two drive shafts 30 are arranged as shown in Fig. 5c respectively at the top and the bottom of the recess 31, also extends a bellows 51, depending on the position of the axes in the longitudinal direction of the recess 31 a gap between the two longitudinal sides of the recess 31, a gap between a longitudinal side of the recess 31 and one of the two drive shafts 30 and a gap between the two drive shafts 30 seals. If one or both drive shafts 30 is spaced from the longitudinal sides of the recess 31, a further bellows is arranged between this drive shaft 30 and the corresponding longitudinal side of the recess 31.

In all arrangements, the magnetic strip 52 shown 4 is preferably on each ^'pointing to an axle side of a bellows 51 is a sealing device as that shown in Fig. Arranged that in an arrangement of an axis located on the edge of the recess 31 with a closure device, including a further magnetic strip on Edge of the recess 31 can cooperate.

The arrangements shown in Fig. 5 are not limited to bellows, but may be applied to other forms of sealing members, e.g. on the sealing lips shown in Fig. 3.

The seal 50 described with reference to FIG. 4 can be modified in many ways. The modifications described below represent developments of the seal 50. Features that have already been described above are therefore not repeated. The features of the modifications described below can also be combined with one another or replaced with ^¬ each other and to other forms of execution are used as the second, for example in the manner described with reference to FIG. 3 first embodiment. Fig. 6 shows a schematic perspective view of a seal 50 a according to a first modification of the second embodiment form.

In addition to the elements described with reference to Fig. 4, the seal 50 a further includes an outer gate 53, which supports by mechanical guidance, the closing action of the two magnet 52 formed by the closure device. The outer gate 53 is connected to the drive shaft 30 or at least arranged to be displaceable together with it and engages around the two magnetic strips 52 from the outside. At least its inner profile is formed so that it follows the outer profile of the drive shaft 30 at a distance and thereby guides the flexible magnetic strips 52 along the outer profile of the drive shaft 30. As a result, the sealing effect of the seal 50 a is improved, in particular in the area of the driving drive axle 30.

Like the drive axle, the outer raceway can preferably be designed as a hollow body and / or made completely or partially of a thermally insulating material. The outer backdrop may also be preferably designed in several parts, which allows a better Mont eability in narrow recesses 31 of the process chamber 4.

FIG. 7 shows a schematic perspective view of a seal 50 b according to a second modification of the second embodiment.

In the seal 50b, the magnetic strip is equipped with neodymium magnets. These are very heat resistant and have strong Kere holding forces than the currently available flexible magnetic strips, but are hard and brittle and thus not malleable to a flexible bar.

Therefore, the flexible magnetic strip 52a according to the present invention / modification is formed of a flexible carrier strip 54 on which a flexible retaining strip 55 is mounted with recesses in which individual magnets 56 are embedded, which are preferably formed as neodymium magnets. The carrier strip and the retaining strip are made of a sufficiently temperature-resistant polymer such as. PA 6 formed. As a result, a good flexibility of the magnetic strip is achieved at the same time high closure force. In addition, a flat ferromagnetic strip 57 for better fixation of the individual magnets and to harmonize the bending line parallel below or above the retaining strip 55 may be arranged (in Fig. 7, an arrangement of the ferromagnetic strip 57 between support bar 54 and retaining strip 55 is shown).

8 shows a schematic perspective view of a seal 50 c according to a third modification of the second embodiment.

The seal 50c differs from that shown in Fig. 7 seal 50b only in that the bellows is formed as Doppelfaltenb 51a ^'alg.

9 shows a schematic sectional view of a seal 50d according to a fourth modification of the second embodiment. In the case of the seal 50d, in addition to or as an alternative to the outer race 53, a counter runway 58, which is likewise connected to the drive axle or at least can be displaced together with it, is arranged such that it supports the closing action by mechanical guidance.

The Gegenkulisse 58 includes teeth 59 which engage on both sides of the drive shaft 30 in the direction of movement in the folds of the bellows and thus guide them mechanically. As a result, the sealing effect of the seal 50a is further improved, in particular when the counter-slide 58 is arranged on both sides of the drive axle 30, in front of and behind the traveling drive axle 30.

Like the drive axle and the outer slide, the counter slide can preferably also be designed as a hollow body and / or completely or partially made of a thermally insulating material and / or in several parts _. be executed.

10 shows a schematic sectional view of a seal 50e according to a fifth modification of the second embodiment.

In the case of the seal 50e, the drive axle 30 is guided on the underside of the recess 31 and is preferably flat on its underside as shown in FIG. 2d. The closure device is formed in the present case by a chain 60, which rests along the longitudinal direction of the recess 31 on the lowermost fold of the bellows 51, pushes it down by its own weight and thereby seals the Ausnahmüng 31. On the drive shaft 30, a positive guide 61 for the chain 60 is mounted, which prevents vertical movement of the chain away from the drive axle and thus acts similar to the outer slide shown in Fig. 6. In particular, it supports the closing movement of the chain after passing through the drive axle.

On the underside of the drive shaft 30, where no lateral movement of the sealing element has to take place, a simple sealing element 62, such as e.g. a mounted on the drive shaft 30 spring plate or a fixed elastic lip for sealing.

11 shows a schematic sectional view of a seal 70 according to a third embodiment of the present invention.

In the seal 70, the sealing element, which is arranged along the longitudinal direction of the recess 31, formed by a chain 71 of hingedly interconnected and overlapping sheet metal blanks. The chain 71 rests on the lower edge of the recess 31 and is guided by a groove .72 formed there. Upwardly, the chain 71 projects into a groove 73 which is formed in the upper edge of the recess 31. Thus, the recess 31 is sealed by the chain 71. Although this form of gap seal, the simplest form of labyrinth seal, can not completely suppress the gas flow between the inside and the outside of the process chamber, but reduce it to an acceptable level.

Also in the seal 70, drive shaft 30 is guided along the underside of the recess 31, and it is preferably formed flat on its underside as shown in Fig. 2d. The chain 71 is lifted by the drive axle 30 and returns behind the drive axle 30 by its own weight in its initial state. The chain 71 thus acts as a sealing element as well as by its own weight as a closure device. The groove 73 must be so deep that the chain 71, even if it is lifted by the drive shaft 30, finds its place. On the drive shaft 30, a positive guide 74 is attached to the chain 71, which prevents vertical movement of the chain 71 away from the drive axle and thus acts as an external backdrop. In particular, it supports the closing movement of the chain after passing through the drive axle.

Since the recess 31 has a maximum height which corresponds to the height ^'of the chain 42, this embodiment of the sealing element is space-saving. In addition, the chain 42 is low-wear and thus has a long life.

The features of the embodiments described above can be combined or exchanged with each other where appropriate and possible. Thus, for example, in the case of the seal formed by sealing lips according to the first embodiment, magnetic strips can be used instead of spring plates as a closure device, or it can additionally be provided outside and / or counter scenery. Conversely, for example, also in the bellows according to the second embodiment, spring plates or spring combs can be used as a closure device. In the embodiments described above, a coater is described as a module to be moved. However, the drive axle can also be intended for another process module which is suitable for carrying out a process required for producing a three-dimensional object, for example a movable exposure module.

Although the present invention based on a Lasersinterbzw. Laser melting device has been described, it is not limited to the laser sintering or laser melting. It can be applied to any methods of manufacturing a three-dimensional object by layering and selectively solidifying a building material.

For example, the laser may include a gas or solid state laser, a laser diode, or any other type of laser. In general, any means by which energy can be applied selectively to a layer of building material can be used. Instead of a laser, for example, a plurality of lasers, another light source, an electron beam or any other source of energy or radiation suitable for solidifying the building material may be used. The invention can also be applied to selective mask sintering, in which an extended light source and a mask are used, or to the absorption or inhibition sintering.

Instead ^'of introducing energy selectively solidifying the applied building material can also be made by 3D ^printing,' for example, by applying an adhesive. In general, the invention relates to the production of an ob- By layering and selective solidification of a building material regardless of the manner in which the building material is solidified. Various types of building materials can be used, in particular powders such as metal powder, plastic powder, ceramic powder, sand, filled or mixed powders.

Claims

Device (1) for producing a three-dimensional object (2) by selective layer-by-layer solidification of building material (13), comprising:

a process chamber (3) with a chamber wall (4) and at least one within the process chamber (3) in a direction of movement (B) via a construction field (10) movable first process module (14) for performing a for producing a three-dimensional object (2 ) is suitable and has at least one transverse to the direction of movement (B) extending drive shaft (30),

wherein the chamber wall (4) of the process chamber has an elongated recess (31) through which the at least one drive axle (30) is passed and along the longitudinal direction of which the at least one drive axle (30) is movable for moving the at least one process module (14) the direction of movement,

wherein at least one flexible sealing element (41; 51; 71) is mounted substantially over the entire length of the recess (31) so that the sealing element (41; 51; 71) has a space between the two longitudinal sides of the recess (31) and / or between a longitudinal side of the recess (31) and the longitudinal side facing the at least one drive axle (30) and / or between two facing sides of two in the transverse direction of the recess (31) staggered drive axles (30) seals, and wherein at least one closure means (42; 52; 71) is arranged to impart a force along the longitudinal direction of the recess (31) to the at least one sealing element (41; 51; 71) to seal the gap between the two longitudinal sides of the seal Recess (31) and / or between a longitudinal side of the recess (31) and the longitudinal side facing the at least one drive axle (30) and / o between two facing sides of two in the transverse direction of the recess (31) staggered drive axles (30) serving direction.

2. Device according to claim 1, wherein

a fixed flexible sealing element (41; 51) is mounted on both longitudinal sides of the recess (31) such that the two sealing elements (41; 51) together each have a gap between the two longitudinal sides of the recess (31) and / or between the two Longitudinal sides of the recess (31) and the longitudinal sides facing sides of at least one drive axle (31) seal, and

a closure device (42; 52) is arranged so that it along the longitudinal direction of the recess (31) on at least one sealing element (41; 51), preferably both sealing elements (42; 52) a force in the space for sealing the inter mediate space between the two longitudinal sides of the recess (31) and / or between one or both longitudinal sides of the recess

(31) and facing this longitudinal side or these longitudinal sides _. Side or sides of the at least one drive axle

(31) serving direction.

3. Device according to claim 1 or 2, wherein

two drive shafts (30) are offset from each other in the transverse direction of the recess (31), parallel to the two longitudinal sides of the recess (31) a flexible sealing element (41; .51) between the two drive axles (30) is mounted so that there is a gap between the two longitudinal sides of the recess (31) and / or between a longitudinal side of the Recess (31) and the longitudinal side facing one of the two drive axles (30) and / or between the two mutually facing side of the two drive axles (30) seals, and

the closure means (42; 52) being arranged to impart a force along the longitudinal direction of the recess (31) to at least one sealing element (41; 51), preferably both sealing elements (41; 52), for sealing the gap between the two Longitudinal sides of the recess (31) and / or between a longitudinal side of the recess (31) and the longitudinal side facing one of the two drive axles (30) and / or between the two mutually facing side of the two drive axles (30) serving direction.

4. Device according to one of claims 1 to 3, wherein

the drive axis (30) in the plane of the chamber wall (4) through which it passes, an elongated, preferably ship-shaped cross-section, in a particularly preferred with a double S-shaped outer contour, whose longitudinal direction in the longitudinal direction of the recess (31 ) runs.

5. Device according to one of claims 1 to 4, wherein

at least one sealing element as a lip (41) or as

Bellows (51) is formed and / or

at least one sealing element made of a rubber-elastic fluoroelastomer and / or fiber-reinforced, in particular fiberglass-reinforced PTFE film and / or Teflon-reinforced fabric is formed.

6. Device according to one of claims 1 to 5, wherein the closure means comprises a mounted on at least one sealing element biased spring plate (42), which is designed in particular as a spring comb.

7. Device according to one of claims 1 to 6, wherein the closure device comprises a mounted on at least one sealing element magnetic strip (52).

8. Apparatus according to claim 7, wherein

the magnetic strip contains a thin ferromagnetic strip (57).

9. Apparatus according to claim 7 or 8, wherein

the magnetic strip a flexible retaining strip (55) with inserted magnets (56), in particular neodymium magnets containing.

10. Device according to one of claims 1 to 9, further comprising an outer gate (53) and / or a counter-guide (58) which is slidably disposed with the drive axle (30) so that it by mechanical guidance of the closing action of the closure device ( 42, 52) and / or the sealing element (41, 51).

11. Device according to one of claims 1 to 10, wherein the drive axle (30) and / or the outer gate (53) and / or the counter-guide (58) are formed as hollow bodies and / or the drive axle (30) and / or the outer slide (53) and / or the counter slide (58) are formed in several parts.

12. The apparatus according to claim 10 or 11, wherein

the counterangle (58) is shaped essentially in the form of a counter-shape to the at least one sealing element (41; 51), preferably to all sealing elements (41; 51), and is arranged and / or mounted in such a way that, during a movement of the drive shaft (30 ), a movement of the sealing element (41; 51) away from the drive axle is reduced, preferably substantially prevented and / or that it returns the sealing element (41; 51) in the direction of movement behind the drive axle (30) to its original position.

13. Device according to one of claims 1 to 12, which

includes at least a second process module, which is movable in the direction of movement (B) and which is drivable together with the first process module (14) by the at least one drive axle (30) or by a further drive axle (30) through the same recess (31 ) is passed.

14. Device according to one of claims 1 to 13, wherein the first and / or the second (s) process module (s) are selected from

a coating module (14) for applying a

Layer of the building material (13) on a construction field (10) is suitable, and / or

an exposure module which is suitable for solidifying the building material (13) applied to the construction field (10).

15. Method for producing a three-dimensional object (2) by selective layer-by-layer solidification of build-up material (13) in a device (1) having a process chamber (3) with a chamber wall (4) and at least one inside the process chamber (3) in a movement direction (B) via a construction field (10) movable process module (14) which is suitable for performing ei Nes for producing a three-dimensional object (2) process and at least one transverse to the direction of movement (B) extending drive axle ( 30),

wherein for moving the at least one process module (14) in the direction of movement (B) at least one transverse to the direction of movement (B) extending drive axle (30) by an elongated recess (31) in the chamber wall (4) of the process chamber (4 ) is moved along the elongated recess (31),

during movement of the drive shaft (30) along the elongate recess (30), at least one flexible sealing element (41; 51; 71) mounted substantially the entire length of the recess (31) has a space between the two longitudinal sides of the recess (31) and / or between a longitudinal side of the recess (31) and the longitudinal side facing the at least one drive axle (30) and / or between two facing sides of two in the transverse direction of the recess (31) against each other ver set drive axles seals , and

a closure means (42; 52; 71) along the longitudinal direction of the recess (31) on the at least one sealing element (41; 51; 71) a force in the for sealing the gap between the two longitudinal sides of the recess (31) and / or between a longitudinal side of the recess (31) and the this longitudinal side facing the at least one drive axle (30) and / or between two mutually facing sides of two in the transverse direction of the recess (31) staggered drive axles (30) serving direction exerts.