WO2017080659A1 - Device and method for producing a three-dimensional object - Google Patents

Abstract

A changing chamber (3) according to the invention is suitable for a device (1) for producing a three-dimensional object (2) by selective layered compaction of buildup material (13), in particular powdered buildup material, at locations corresponding to the cross section of the object (2) to be produced in the respective layer under the effect of electromagnetic radiation (22). The changing chamber (3) comprises a building space (5) with a building platform (9), on which the three-dimensional object (2) can be produced, a storage container (6) for storing buildup material (13), a coater device (14) for applying a layer of the buildup material (13) to the building platform (9) or to an already selectively compacted layer of the buildup material (13) and a window (15) for coupling in electromagnetic radiation (22).

Description

 Apparatus and method for

 Create 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 a building material is repeatedly applied and the building material in each layer selectively solidified by selective irradiation with a laser beam.

Such a device is known for example from DE 10 2004 057 866 AI. The machine housing of the device is separated into two housing sections. In the first section, a container is provided with a construction space in which the three-dimensional object is produced, and a powder supply and a powder applicator. To remove the finished object, the container is movable in the second housing section. In the described device, however, vapors and gases which are formed during laser sintering can precipitate on the lid of the container and thus impair the functionality of the scanner device arranged on the lid.

The object of the present invention is to provide an alternative, preferably improved device for producing a three-dimensional object, and such a method. In particular, it is aimed at a simpler loading and unloading of the device and their cleaning. Furthermore, the invention preferably contributes to making the manufacturing process of three-dimensional objects more economical by saving time.

The object is achieved by a changing chamber according to claim 1, a device according to claim 12 and a method according to claim 13. Further developments of the invention are specified in the subclaims. In this case, the methods can also be developed by the features of the devices set out below or in the subclaims, or vice versa.

The exchangeable chamber according to the invention is suitable for a device for producing a three-dimensional object by selective layer-by-layer solidification of building material, in particular pulverulent building material, on the cross section of the object to be produced in the respective layer corresponding points under the action of electromagnetic radiation. The changeable chamber comprises a construction space with a construction platform in which the three-dimensional object can be produced, a storage container for storing build-up material, a coater for applying a layer of the build material on the build platform or on an already selectively solidified layer of the build material and a window for coupling in electromagnetic radiation.

The change chamber is intended to be removed after a construction process from a device for producing a three-dimensional object by means of a generative layer construction method or to be installed prior to a construction process in such a device. It is preferably formed in one piece and thus a separate, closed space which can be introduced into and removed from the device. In this context, "integral" is understood to mean that the changing chamber forms an integral component at least in a state installed in the device, preferably also during an operation of introduction and / or removal This ensures, for example, that the powder essentially remains in this space during the entire construction process and that gases and dirt particles formed during the construction process can not escape, thus protecting the device from contamination , which considerably reduces the cleaning effort, since only the cleaning of the exchangeable chamber is required and this can be completely removed from the device for a simple cleaning, it also makes it possible, for example, to replace the exchangeable chamber immediately after loading To remove the completion of a construction process out of the device, so that the device without Time delay for a further construction process is ready, which can be started, for example, after the introduction of a second exchange chamber provided as exchange unit in the device. This time saving increases the efficiency and thus the economy of such a device.

Preferably, the changeable chamber has a removable lid which more preferably has the coupling window. The removable lid provides good access to the elements located inside the interchangeable chamber, thus allowing easy intervening in the interchangeable chamber, for example, to replenish the powder supply prior to the manufacturing process and to remove the object or to clean the elements after the manufacturing process. In addition, it is possible to arrange the exposure device in the device outside the exchangeable chamber, since the energy beam can pass through the coupling window into the replaceable chamber. This prevents the formation of gases during the construction process on the exposure device and thus impair their function.

Preferably, the change chamber is closed with a lid substantially gas-tight. In this context, the term "substantially gas-tight" is understood to mean a state in which at most negligible gas can enter or leave the exchange chamber if the gas pressure lies within a value range which is usual for the operation of the device In addition, the interchangeable chamber can have connections for the supply and / or discharge of a protective gas Construction process to perform under a defined process atmosphere. Furthermore, during the construction process, resulting gases and dirt particles can be sucked through a protective gas flow and thus removed from the installation space.

Preferably, the coater device is attached to the installation space facing side of the lid. Thereby, a discharge of the building material out of the change chamber, and thus contamination of the device, avoided. In addition, a coating device arranged on the cover can be moved well over the installation space and the storage container.

In addition, the change chamber may comprise an overflow container for receiving excess build-up material. The unused building material can thus be collected and used for another construction process.

Preferably, the installation space is designed as a construction shaft and / or the storage container is designed as a supply shaft and / or the overflow container is designed as an overflow shaft. The design of said container as wells in the interchangeable chamber is easy to implement. In addition, a coating device arranged on the cover can apply the building material in a simple manner from the supply shaft in the building shaft.

Preferably, a vertically displaceable platform is arranged in the reservoir. Depending on the amount of build material already removed from the storage container, the displaceable platform can be moved upwards in such a way that the surface of the stored build-up material lies substantially in the plane of the container rim, or the building material is discharged by moving the platform up out of the container. Thus, a user can easily remove the build-up material from the coater device.

The platform and / or the construction platform provided in the storage container preferably have seals in order to seal the storage container or the installation space to the bottom thereof. This prevents unsolidified build-up material from escaping from the storage container or the installation space.

Preferably, the platform provided in the reservoir and / or the building platform on its underside a fastening device for mechanically coupling the platform to a provided in the device support device, wherein the fastening device is preferably designed as a mechanical quick-release system. This makes it possible to attach the platform to a provided in the device carrier device in a simple manner.

In addition, the interchangeable chamber may have on its outer side a coupling device, in particular for coupling to a transport device. Thus, a simple introduction and removal of the change chamber in the device or from this out is made possible.

A device according to the invention for producing a three-dimensional object by selective layer-by-layer solidification of building material at the cross-section of the object to be produced in the respective layer corresponding locations comprises a radiation source for emitting electromagnetic radiation, and a change chamber, which from the device is removable. Thus, the steps of filling the reservoir with building material before the construction process, as well as the cooling, the removal of the finished object and the cleaning of the exchangeable chamber after completion of the construction process with removed removable chamber outside of the device.

A method according to the invention for producing a three-dimensional object by selective layer-by-layer solidification of building material at points corresponding to the cross-section of the object to be produced in the respective layer under the action of electromagnetic radiation is carried out using a changing chamber. The changeable chamber comprises a construction space with a construction platform on which the three-dimensional object is produced, a storage container in which building material is stored, a coating apparatus which applies a layer of the construction material to the construction platform or on an already selectively solidified layer of the building material and a window for coupling in electromagnetic radiation. In this process, the entire powder handling takes place in the exchange chamber, so that no powder in the

Outside or in the device passes.

In the closed state, the changing chamber is preferably introduced into a device for producing a three-dimensional object and / or removed from the device in the closed state. This prevents powder from entering the device and / or contaminants in the change chamber. Preferably, the change chamber is substantially directly after

Completion of the selective stratified solidification of the structural removed material in all layers of a device for producing a three-dimensional object and cooled substantially outside the device. As a result, the device can be used immediately after completion of the construction process for a further construction process. This time saving increases the efficiency and thus the economy of such a device.

Further 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 a device according to an embodiment of the invention for producing a three-dimensional object in layers.

Fig. 2 is a schematic perspective view of a change chamber included in the apparatus shown in Fig. 1;

Fig. 3 is a schematic, sectional view of the changing chamber from above without cover.

Fig. 4a is a schematic view of the changing chamber of FIG

 4b shows a sectional view along the line A A shown in FIG. 4a.

FIGS. 5a-5c are schematic external views of the apparatus shown in FIG. 1 for layering a three-dimensional object. An apparatus according to an embodiment of the present invention will be described below with reference to FIG. The device shown in FIG. 1 is a laser sintering or laser melting device 1. For constructing an object 2, it contains a changing chamber 3 with a wall 4.

In the exchange chamber 3, a storage shaft 6 for a festungsig by electromagnetic radiation building material 13, an overflow shaft 7 for receiving excess Aufbauma- material 16, and a building shaft 5 are arranged. In the building shaft 5, which defines the space, a building platform 9 is arranged, which closes the building shaft 5 down and thus forms its bottom. For sealing the building shaft 5 downwards, the construction platform 9 preferably comprises seals which are not shown in FIG. The three-dimensional object 2 can be built on the construction platform 9 in the construction shaft 5. The building platform 9 is fastened on or to a support device 8 provided in the device 1 and movable in a vertical direction V outside the changeable chamber 3. In FIG. 1, the object 2 to be formed in the building shaft 5 on the construction platform 9 is shown in an intermediate state with several solidified layers surrounded by unconsolidated construction material 11. In the supply shaft 6, a further platform 36 is arranged, following the supply shaft 6 closes down and thus forms its bottom. For sealing the supply shaft 6 downwards, the platform 36 preferably comprises seals, which are not shown in detail in FIG. The platform 36 is on or at another outside of the change chamber 3 in the

Device 1 provided in a vertical direction V movable support device 37 attached. The carrier device 37 and the building platform 9 may also be integrally formed.

Furthermore, the wall 4 of the change chamber 3 on its underside two recesses 39, 40, through which provided in the device 1 carrier devices 8, 37 can engage in the change chamber. The recesses 39, 40 are at least as large as the maximum horizontal extent of the support devices 8, 37 or of the (construction) platform (s) 9, 36.

Through the upper edge of the building shaft 5, a working level 10 is defined. Preferably, the storage shaft 6 and / or the overflow shaft 7 are arranged in the exchange chamber 3 such that the upper edge of the storage shaft 6 and / or the upper edge of the overflow shaft 7 lie in the working plane.

The changing chamber 3 further includes a movable in a horizontal direction H coater device 14 for applying the building material 13 to the working plane 10. For moving the coater 14, a not shown in detail drive outside the wall 4 of the interchangeable chamber 3 is provided. The coater device 14 is connected to the drive by means of a drive shaft 31 (not shown in FIG. 1).

The laser sintering device 1 further includes 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 15 which is arranged in the top of the wall 4 of the change chamber 3 is focused on the working level 10. 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.

As shown in FIG. 2, the exchangeable chamber comprises a removable cover 12 which has the coupling-in window 15 for coupling in the laser radiation 22. The exchangeable chamber 3 is preferably closed in a gas-tight manner with the lid 12 attached, so that essentially no gas exchange takes place with the ambient air. In addition, in the wall 4 of the change chamber 3, a gas supply 41 and a gas outlet 42 are provided for supplying or discharging a protective gas. This makes it possible to maintain a defined gas atmosphere in the change chamber 3 during the construction process. The coupling device 30 and the drive axle 31 will be described later with reference to FIGS. 5a-5c and 4a-4b, respectively.

Fig. 3 shows a view of the change chamber 3 from above without patch cover 12. The change chamber 3 comprises a

Building shaft 5, which is arranged centrally in the interchangeable chamber 3, as well as a supply shaft 6 and an overflow shaft 7. The supply shaft 6 and the overflow shaft 7 adjoin on opposite sides of the building shaft 5 at this. On two opposite outer sides of the wall 4, a gas supply 41 and a gas outlet 42 are provided for supplying or discharging a protective gas. As shown in FIGS. 4a-4b, the coater device 14 is arranged on the side of the cover 12 facing the construction shaft 5, ie on the underside thereof. In order to ensure the mobility of the coater device 14 in a horizontal direction H, which in FIG. 4a extends in the plane of the drawing and in FIG. 4b perpendicular thereto, the coater device 14 is connected by means of a drive shaft 31 to a drive (not shown). The drive axle 31 runs in FIG. 4 a perpendicular to the drawing plane and in FIG. 4 b parallel to the drawing plane. The drive shaft 31 is movable so that the coater apparatus 14 is reciprocally movable in a horizontal direction H between the hopper 6 and the weir shaft 7. The construction shaft 5 shown in Fig. 4b is completed or sealed down through the platform 9. On the underside of the building platform 9, ie on the side facing away from the building shaft 5, a fastening device for fixing to a provided in the device 1 support device 8 is arranged. The fastening device shown in Fig. 4b is a pin 32 or a plurality of pins 32, which is or are suitable to engage in sockets of the support device 8 and thus to mechanically connect the building platform 9 to the support device 8.

FIGS. 5a-5c show further schematic views of the device 1 shown in FIG. 1. The laser sintering or laser melting device 1 comprises a housing 38 on which the exposure unit 20 is arranged. The housing 38 has an opening 34, which is preferably closable by a door, not shown, or other closure device. The change Selkammer 3 is introduced through the opening 34 in the device 1 and removable. For this purpose, the change chamber 3 has a coupling device 30, on which a transport device can act. Furthermore, the device 1 has a carrier device 37, which on its upper side, ie the side facing the change chamber 3, jacks 35 for mechanically coupling the platform 36 of the storage shaft 6 to the support device 37, and a support device 8, which on its upper side , ie the side facing the changeable chamber 3, bushings 35 has for mechanically coupling the

Building platform 9 to the support device 8. The carrier devices 8, 37 are arranged side by side and below the interchangeable chamber 3 and by means not shown drives in a vertical direction V movable. On the side of the housing 38 lying opposite the opening 34, a connection 33 is provided for supplying and discharging a protective gas into or out of the interchangeable chamber 3. However, the connection 33 does not have to be arranged on the side of the housing 38 opposite the opening 34; it can instead be arranged on any desired side of the housing 38. The port 33 may also be configured as two separate ports for supplying and discharging the gas.

In operation, a changing chamber 3 is prepared outside the device 1 for the construction process. For this purpose, for example, the platform 36 of the storage shaft 6 is brought into the lowermost position and the supply shaft 6 filled with building material 13. Subsequently, the change chamber 3 is closed with the lid 12, preferably sealed gas-tight, and by means of a transport device through the opening 34 of the device

1 introduced into this. The transport device can be configured for example as a lift truck and engages the Coupling device 30, which is provided on the outside of the exchange chamber, to. However, it is also possible to introduce the change chamber 3 without using a transport device in the device 1. For example, the changing chamber 3 can also be introduced into the device 1 by hand.

Now, the carrier devices 8, 37 are moved so that the pins 32 on the undersides of the building platform 9 and the platform 36 in the sockets 35 of the support devices 8, 37 engage and the build platform 9 and the platform 36 thus attached to the support devices 8, 37 are and can thus be moved in a vertical direction V. For applying a layer of the building material 13, the building platform 9 is first lowered by a height which corresponds to the desired layer thickness, and the platform 36 is moved upwards in order to supply the coating device 14 with a sufficient amount of building material 13. In this case, the platform 36 can either be moved so far upwards that the surface of the stored building material 13 lies substantially in the working plane 10, or that the building material 13 is discharged from the supply shaft 6 by moving the platform 36 upwards and thus the coating device 14 is supplied.

By moving the coating apparatus 14 over the working plane 10, a layer of the building material 13 is then applied to the building platform 9 or to an already selectively consolidated layer of the building material 13. 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 building shaft 5. Excess build-up material 16 can thereby the overflow shaft 7 are supplied. Subsequently, the cross section of the object 2 to be produced is scanned by the laser beam 22, so that the powdery building material 13 is solidified at the points corresponding to the cross section of the object 2 to be produced. These steps are repeated until the object 2 is completed.

Immediately after completion of the construction process, the carrier devices 8, 37 are moved to a lower position and the build platform 9 and the platform 36 are decoupled from the carrier devices 8, 37. Subsequently, the change chamber 3 is removed by means of the transport device through the opening 34 of the device 1 out. Immediately after removal of the change chamber 3, a further change chamber 3 can be introduced into the device 1 to perform a further construction process.

The changeable chamber 3 or the finished object 2 can now undergo further process steps as needed. These may include the following steps or a selection thereof in substantially any order:

 Removing the cover 12 from the exchangeable chamber 3,

 Cooling the manufactured object 2,

 Removing the uncontaminated superstructure material 11 surrounding the object 2,

 Removing the object 2 from the exchangeable chamber 3,

 Removing the building material 13 from the overflow shaft and / or from the supply shaft, and

- Cleaning the changing chamber 3 and the elements arranged therein. In the embodiments of a changing chamber described above, a building shaft, a storage shaft and (optionally) an overflow shaft are provided. However, it is also possible to provide a plurality of construction shafts and / or a plurality of storage shafts and / or a plurality of overflow shafts in the exchangeable chamber. Thus, for example, one supply chute can each be arranged on each side of the construction can, so that the application device for applying a first layer moves from the supply chute arranged on the first side of the construction shaft over the construction shaft to the second supply shaft located on the opposite side of the construction shaft becomes. For applying the subsequent layer, the coater device is then moved from the second supply shaft via the building shaft back to the first supply shaft. Thus, it is not necessary, the coater after applying a

Shift back over the construction field back to the storage shaft, which makes the construction process more time efficient. Furthermore, for example, it is also possible to provide a plurality of construction shafts so that a plurality of three-dimensional objects can be produced simultaneously on different construction platforms in a changeable chamber.

Furthermore, the cover of the interchangeable container can be designed as a non-removable lid and be provided for engagement in the interchangeable chamber, a door or other closure element in the wall of the interchangeable chamber.

Also, at least one of the recesses 39, 40 may not be provided on the underside of the interchangeable chamber, but for example in the side wall of the interchangeable chamber. Thus, at least one of the carrier devices 8, 37 does not engage below, but eg laterally in the exchange chamber. The fastening device of the construction platform or the platform of the storage shaft can be adapted thereto and provided, for example, laterally of the construction platform or the platform.

The fastening device for attaching the construction platform and / or the platform to the corresponding support device need not be designed as a pin which engages in a socket. Rather, any mechanical fastening system, in particular quick coupling system, is conceivable. For example, the construction platform or platform can be fastened to the support device by means of a rocker arm. Furthermore, non-mechanical, such as magnetic, fastening mechanisms are conceivable.

The coupling device of the interchangeable chamber, on which the transport device acts, need not be arranged laterally of the interchangeable chamber. Thus, the changing chamber may e.g. also be arranged on the visible through the opening in the housing of the device front of the removable chamber.

Furthermore, feet and / or rollers can be provided on the exchangeable chamber, preferably on its underside, in order to ensure stable stability or movability of the exchangeable chamber, for example outside the device.

Furthermore, means for introducing and / or removing and / or anchoring the changing chamber may be provided in the device, such as rails and / or a link, and an alignment and / or adjusting element for precise positioning and / or alignment of the change chamber in the device , The change chamber may have further seals to prevent leakage of build material from the change chamber and / or ingress of contaminants into the change chamber. Also, the change chamber can be thermally insulated.

Thereby, the outer surface can be maintained at a lower temperature than the inner surface of the chamber wall, which facilitates the removal of the changer chamber immediately after the construction and prevents burns of an operator.

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 coating and selectively solidifying a building material by the action of electromagnetic radiation.

The laser may include, for example, a gas or solid state laser or any other type of laser. In general, any means may be used to selectively apply electromagnetic radiation to a layer of building material. The invention can also be applied to selective mask sintering using an extended light source and a mask, or to absorption sintering.

Various types of building material can be used, in particular powdery building material such as metal powder, plastic powder, ceramic powder, sand, filled or mixed powder.

Claims

1. changing chamber for a device (1) for producing a three-dimensional object (2) by selective layer by layer Solidification of building material (13), in particular powdery building material, on the cross-section of the object to be produced (2) in the respective layer corresponding locations under the action of electromagnetic radiation (22), wherein the interchangeable chamber (3)  a construction space with a building platform (9) on which the three-dimensional object (2) can be produced,  a storage container for storing building material (13),  a coater device (14) for applying a Layer of the building material (13) on the building platform (9) or on an already selectively solidified layer of the building material (13) and  a window (15) for coupling in electromagnetic radiation (22). 2. changeable chamber according to claim 1, characterized in that the interchangeable chamber *, .. (3) has a removable cover (12), which preferably has the coupling window (15). 3. changeable chamber with cover (12) according to claim 2, characterized in that the interchangeable chamber (3) with attached cover (12) is gas-tight manner closed. 4. interchangeable chamber according to claim 3, characterized in that the interchangeable chamber (3) has connections (41, 42) for the supply and / or discharge of a protective gas. 5. changeable chamber according to one of claims 2 to 4, characterized in that the coater device (14) is attached to the installation space facing side of the lid (12). 6. changeable chamber according to one of claims 1 to 5, characterized in that the interchangeable chamber (3) comprises an overflow container for receiving excess building material (16). 7. changeable chamber according to one of claims 1 to 6, characterized in that the space is designed as a construction shaft (5) and / or the reservoir is designed as a supply shaft (6) and / or the overflow container is designed as overflow shaft (7). 8. changeable chamber according to one of claims 1 to 7, characterized in that in the reservoir a displaceable in the vertical direction platform (36) is arranged. 9. changeable chamber according to one of claims 1 to 8, characterized in that the platform (36) according to claim 8 seals for sealing the reservoir to the bottom and / or the construction platform (9) has seals for sealing the space to the bottom out. 10. changeable chamber according to one of claims 1 to 9, characterized in that the platform (36) according to claim 8 and / or the building platform (9) on its underside has a fastening device for mechanically coupling the platform (9, 36) to an in the device provided carrier device (8, 37), wherein the fastening device is preferably designed as a mechanical quick-release system. 11. Interchangeable chamber according to one of claims 1 to 10, characterized in that the interchangeable chamber (3) has on its outer side a coupling device (30), in particular for coupling to a transport device. 12. An apparatus for producing a three-dimensional object (2) by selective layer-by-layer solidification of Aufbaumate- rial (13) on the cross section of the object to be produced (2) in the respective layer corresponding points, with  a radiation source (21) for emitting electromagnetic radiation (22), and  a changing chamber (3) according to one of claims 1 to 12, characterized in that  the change chamber (3) from the device (1) can be removed out. 13. A method for producing a three-dimensional object (2) by selective layerwise solidification of Aufbaumi-material (13) at the cross section of the object to be manufactured (2) in the respective layer corresponding locations under the action of electromagnetic radiation (22) and using a change chamber ( 3), which exchange chamber (3)  a construction space with a building platform (9) on which the three-dimensional object (2) is produced, a reservoir, in which building material _. (13) is stored, a coater device (14) which applies a layer of the build material (13) on the build platform (9) or on an already selectively solidified layer of the build material (13) and a window (15) for coupling in electromagnetic radiation (22). 14. The method according to claim 13, characterized in that the interchangeable chamber (3) in the closed state in a device (1) for producing a three-dimensional object (2) is introduced and / or removed in the closed state from the device (1). 15. The method according to claim 13 or 14, characterized in that the changing chamber (3) essentially immediately after completion of the selective layerwise solidification of the building material (13) in all layers of a device (1) for producing a three-dimensional object (2 ) and substantially cooled outside the device (1).