WO2019206951A1

WO2019206951A1 - Method and device for de-powdering a construction chamber

Info

Publication number: WO2019206951A1
Application number: PCT/EP2019/060448
Authority: WO
Inventors: Géza KOSCSÁK; Axel Boi
Original assignee: Chiron-Werke Gmbh & Co. Kg
Priority date: 2018-04-24
Filing date: 2019-04-24
Publication date: 2019-10-31
Also published as: DE102018109830A1

Abstract

The invention relates to a method and a device for de-powdering a construction chamber (44) of a system (10) for additive manufacturing, comprising: at least two lances (102, 104, 106, 108; 202) which are each provided with at least one nozzle (112, 114, 116, 118; 212; 222), the lances (102, 104, 106, 108; 202) being situated, at least in an operating position, adjacently to at least one additively manufactured component (56) in the construction chamber (44); a handling unit (140) for moving the at least two lances (102, 104, 106, 108; 202) relative to the construction chamber (44); a supply unit (130) for supplying a pressurised gaseous fluid; an outlet (162; 166); and a control unit (170) which is coupled to the at least two lances (102, 104, 106, 108; 202), the handling unit (140) and the supply unit (130) to control same so that, when the at least two lances (102, 104, 106, 108; 202) are used in the construction chamber (44), a directed stream of gas can be generated for powder removal in order to discharge the stream of gas via the outlet (162; 166). The invention also relates to a system for additive manufacturing and to the use of a device for de-powdering.

Description

Method and device for deflating a construction space

The present disclosure relates to a method and apparatus for Entpulvern a space of an additive manufacturing machine. Furthermore, the present disclosure relates to a plant for the additive production of workpieces, in particular a powder bed system, which is provided or coupled with such a device for Entpulvernvern.

More recently, additive manufacturing has become increasingly important. Additive manufacturing is commonly referred to as 3D printing. Previously, due to the still very limited application possibilities, the term rapid prototyping was used to designate machines of additive manufacturing. Another common name is generative manufacturing. There are various methods for additive manufacturing are known, which are based on arranging powder in a space layer by layer and partially solidified by introducing energy and / or other components, so that layer by layer, a component is formed. [0003] This regularly results in at least partially solidified workpieces being present on the one hand in a space provided by a building chamber after the completion of the layer buildup, and on the other hand a considerable amount of unconsolidated / loose powder. This excess powder must be at least partially removed so that the workpiece (or a plurality of workpieces) can be removed.

[0004] The removal of the powder is also referred to as defoaming or depowdering. There are various approaches to the Entpulvern known. A traditional approach involves manual de-powdering. In other words, excess powder can be sucked out of the mouth and / or detached from the component with a brush.

[0005] Automated defoaming formulations are known, for example, from US 2002/0090410 A1 or US 2007/0126157 A1. Such approaches still do not use targeted flow control. It has been found that known approaches may take considerable time to achieve a satisfactory result. This is not problematic when using additive manufacturing in prototype construction or in individual production. However, if additive manufacturing processes are also used for mass production or even for mass production, the high time required is unacceptable.

From the post-published US 2018/0207889 A1 a device for pneumatically assisted removal of powder from a space of a machine for additive manufacturing is known, wherein the device has a unit which is sealingly coupled to the space, the unit at least one Connection for introducing compressed air into the space and a connection for discharging compressed air and powder residues from the space has.

Against this background, the present disclosure has for its object to provide an apparatus and a method for Entpulvern a space of a plant for additive manufacturing, which leads to a reduction in manufacturing times contribute. In addition, the decoupling should be automated and carried out with high quality and high removal rate, so that rework can be further reduced. The decoupling should be gentle to the components and energy-efficient. Furthermore, as far as possible, the required amount of fluid and / or the pressure of the fluid for the removal of powder should be reduced. Furthermore, the Entpulvern should be such that the excess powder is fully recyclable as possible. Furthermore, the dust exposure should be effectively reduced, such as by an even greater amount of excess powder is automated and can be discharged without manual intervention.

In addition, a plant for additive manufacturing is to be specified, which is provided with a device for Entpulvern.

[0009] With regard to the device, this object is achieved by a device for decoupling a construction space of an installation for additive manufacturing, which has the following consequences:

at least two lances, which are each provided with at least one nozzle, wherein the lances are arranged at least in an operating position in the installation space adjacent to at least one additively manufactured component,

a handling unit for moving the at least two lances relative to the installation space,

a delivery unit for providing a pressurized gaseous fluid,

an outlet, and

a control unit, which is coupled to the at least two lances, the handling unit and the supply unit for their control, so that using the at least two lances in the space a directed gas flow for powder removal can be generated in order to remove the gas flow through the outlet .

wherein the nozzles of the lances are directionally aligned in a circumferential direction to produce the directional gas flow. The object of the invention is fully achieved in this way.

In accordance with the invention, instead of an arbitrary flow, a defined directed gas flow is generated in order to remove the excess powder in an ordered manner. The directed gas flow preferably takes place along a defined flow path. It is essential that the at least two lances are connected with their nozzles fluidically "in series". In other words, given the direction of the directed flow, one lance is offset in the flow direction to the other lance. In this way, a total of a directed flow can be generated, which does not set arbitrarily. The flow direction may be, for example, a circumferential direction.

The generation of the directed gas flow may comprise a defined relative movement between the lances or their nozzles and the installation space or the powder bed. Preferably, the relative movement is a vertical relative movement. The vertical relative movement may comprise a vertical movement of the lances and / or a vertical movement of the powder bed, in particular a building platform, which carries the powder bed.

In other words, it is preferred if the lances can be introduced "from above" in the space. In this way, a tracking movement can be generated when layer by layer, the excess powder is removed.

[0014] The lances are each provided with at least one nozzle or nozzle arrangement. The nozzle is a gaseous fluid outlet nozzle. This can be on the one hand compressed air. However, it is also conceivable to use an inert gas or a corresponding mixture.

The space is defined by a chamber. The installation space results in the chamber, whereby a regular delineation is made by a moveable construction platform. In the space also several components / workpieces can be arranged. This is done regularly to increase the application rate and productivity. The Chamber can have a rectangular or round cross-section in the travel direction of the platform.

The handling unit is designed, for example, to move the lances in such a way that the height of the nozzles and / or optionally also the orientation of the nozzles can be changed.

Overall, an increase in occupational safety or relief for the operator may result since the powder can be removed and further processed / recovered in a closed system or cycle without significant manual intervention.

The device can be designed as part of a plant for additive manufacturing, in particular a powder bed plant. It is also conceivable to carry out the device separately from such a machine. In an exemplary embodiment, the chamber defining the installation space can be removed from the production plant and inserted into the apparatus for the removal of powder.

According to an exemplary embodiment, there is precisely one outlet for discharging the fluid flow carrying parts of the loose powder. The outlet is provided, for example, on an upper side of the installation space or the chamber defining the installation space. According to an exemplary embodiment, the outlet is designed funnel-shaped and with its open area facing the installation space. According to an exemplary embodiment, the outlet is provided centrally in a cover which closes the installation space during the descaling. In this way, the formation of the desired flow shape, preferably a circular flow, spiral flow or cyclone flow, promoted.

The generation of the directed gas flow may further comprise a coordinated movement of the lances, this also being defined relative movements between the lances or their nozzles and / or defined proper movements (rotational movement or pivoting movements) of the lances or their nozzles may include. In an exemplary embodiment, the device has at least three lances, which are placed or placed in a circular space in the space to at least one additively manufactured component. By way of example, three lances can each be arranged at an angular distance of 120 ° along an imaginary circular path / circumferential path. By way of example, four lances can each be arranged at an angular distance of 90 ° along an imaginary circular path / circumferential path. In this way, by combining the respective individual flows, a defined directed total flow can result.

The nozzles of the lances are aligned in a circumferential direction in the same direction to generate the directed gas flow. This includes embodiments in which three or more vertically oriented lances are arranged with the respective nozzles along a circular path / circumferential path in the installation space around the component or the components. Accordingly, the nozzles may be oriented substantially tangentially to the imaginary circular path to produce the directional flow.

In other words, according to exemplary embodiments, the nozzles face in a clockwise (clockwise) or counterclockwise (counterclockwise) direction, whereby tolerances for the "viewing direction" can of course be provided. The tangential orientation in this embodiment relates to the viewing direction. Directional equals in this embodiment that all nozzles are aligned clockwise or counterclockwise. The alignment may be a basic alignment or coarse alignment, which deviates from the operation during operation, for example by pivoting / oscillating the lances with the nozzles.

According to a further exemplary embodiment, the control unit is adapted to arrange the lances such that in a chamber which defines the space, a circular flow, cyclone flow or circumferential flow results around the at least one component. For this purpose, it is advantageous to align the nozzles such that the respective partial flows complement each other. In other words, according to this embodiment, the lances are arranged with their nozzles "in series" to produce a flow with a circular flow path, which is fed directly or indirectly to the outlet. According to a further exemplary embodiment, the lances and the outlet are arranged such that results in a cyclonic flow. Accordingly, the flow is spiral, starting from an initial diameter, the radius of the flow path gradually becomes smaller, the flow path increases and approaches the outlet.

[0026] According to another exemplary embodiment, the nozzles are configured to eject the pressurized fluid in a directional manner. This includes designs in which the lances are provided with a plurality of nozzles or with a nozzle with individual nozzle fingers. Thus it is conceivable to adjust or operate the nozzles in such a way that a fanned-out fluid jet results. Furthermore, it is conceivable to adjust or operate the nozzles in such a way that a focused fluid jet results. It is also conceivable to design the nozzles such that a fluid jet with "compressed" cross-section (oval cross-section or slot-like cross section) results.

According to a further exemplary embodiment, a respective major axis of the nozzles has less than 30 ° deviation from the horizontal. Overall, therefore, the flow is initially oriented substantially horizontally. The flow resulting at the outlet of the nozzle preferably has a defined opening cone. A small opening cone can contribute to the generation of a defined directed flow. It is understood that the nozzles may also be slightly inclined, so that an overall upward cyclone flow results, in particular if the outlet is arranged on an upper side in the region of a cover.

According to an exemplary embodiment, the nozzles have a plurality of outlet openings, for example in the form of finger-shaped branches. This also includes designs in which a nozzle has a plurality of individual nozzles or nozzle fingers. Furthermore, embodiments are conceivable in which a lance has a plurality of spatially-spaced or differently oriented nozzles. This may comprise a plurality of nozzles, which are arranged one above the other in series, ie vertically spaced from each other. It is also conceivable to provide a plurality of nozzles, which are distributed circumferentially and each project radially from the lance. According to a further exemplary embodiment, the lances are vertically movable. This can be used to generate a tracking motion in order to be able to follow the part exposed piece by piece. Furthermore, it is also conceivable to let the lances oscillate vertically in order to increase the removal rate. This oscillating motion may be superimposed on a global vertical motion. It is understood that the global vertical movement can also be generated by a vertical movement of the platform in the building chamber. The movement (vertical movement) of the individual lances can be synchronized in order to be able to thoroughly disperse them.

According to a further exemplary embodiment, the lances are pivotable about their longitudinal axis. On the one hand, this can include a positioning movement with regard to the angular orientation. Furthermore, this may include an oscillating pivoting motion in order to increase the removal rate. In other words, it is conceivable to arrange two, three or four lances along an imaginary circular path / circumferential path and to first align the lances so that their nozzles are aligned approximately tangentially. However, it is additionally conceivable to allow the nozzles to oscillate about a central position, for example in a range of +/- 15 ° or +/- 30 ° about the tangential position. The movement (pivoting movement) of the individual lances can be synchronized.

[0031] According to a further exemplary embodiment, the nozzles can be tilted. Similar to the oscillations about the longitudinal axis of the lance, the nozzles can oscillate about an axis oriented transverse to the longitudinal axis of the lance. Also in this way the removal rate can be increased. The lances can sweep a larger area to release excess powder from the component.

According to a further exemplary embodiment, the lances are oriented vertically. In other words, two or more lances are provided, which are arranged parallel to one another. By way of example, the lances protrude from above into the installation space. This leads in this embodiment to the fact that the peripheral walls of the chamber, which defines the installation space, need not be provided with openings or other openings for the lances. [0033] According to another exemplary embodiment, a cover for the installation space is further provided, wherein the at least two lances are guided through the cover. By way of example, the handling unit, at least parts of which are also arranged on the cover. The cover may be about a lid or a similar component. The cover may carry one or more drives for moving the lances and / or the nozzles.

According to a further exemplary embodiment, the outlet is also arranged in the cover. In other words, in the construction space, a circular flow or circular flow can result, which is directed spirally upwards in the direction of the outlet, similar to a cyclone. The outlet is coupled, for example, with a suction device, which can also contribute to the flow guidance and to discharge the loose powder.

According to a further exemplary embodiment, the control unit is designed to move the lances defined relative to a arranged in the powder bed component. In exemplary embodiments, this comprises a tracking movement, in which the lances with their nozzles follow a level of the powder bed vertically, for example at a defined distance. On the one hand, this can be achieved by actively moving the lances vertically. On the other hand, this can be effected by a vertical process of the platform.

[0036] According to another exemplary embodiment, the control device is designed to drive the at least two lances in a coordinated manner. This comprises at least coordinated vertical movements or pivoting movements. In other words, it is conceivable to bring about a certain dynamics in the process of Entpulverns about the movement of the lances themselves. This may include, for example, a slightly oscillating beam guidance. This may, for example, relate to a vertical position of the nozzle. However, this may also relate to a pivoting of the nozzle about a horizontally oriented axis. In addition, this may also relate to a swiveling of the nozzle about a vertically oriented axis. Such a coupled movement can further increase the removal rate. By way of example, it is conceivable to match corresponding movements of the individual lances or nozzles to one another in such a way that, overall, a uniform or oppositely oriented adjusting movement results. In other words, an oscillating movement of the lance and / or nozzle may be followed by a harmonic function, such as a sine function having two extremes.

It is now conceivable that all of the lances and their nozzles oscillate in a uniform manner, that is, they also simultaneously pass through their respective extreme positions. Alternatively, however, it is also conceivable to provide a phase difference so that the involved lances and / or nozzles assume their extreme positions at different times. The movements can be synchronized accordingly, with a "phase shift" being provided.

[0039] According to a further exemplary embodiment, the control device is designed to move the at least two lances in opposite directions (that is, in opposite directions). This can include on the one hand a vertical movement and on the other hand, a rotary movement / pivoting movement. The movement between the extreme values can follow a harmonic function.

[0040] According to a further exemplary embodiment, the control device is designed to permit a first relative movement between the lances (i.

within the group of lances) and to combine a second relative movement between the lances and the installation space. This includes, for example, a (global) vertical relative movement between the lances and the installation space / powder bed and a movement superimposed on this movement. The superimposed movement may, on the one hand, comprise a vertical oscillation. Alternatively or additionally, the superimposed movement may also comprise an oscillation about a vertical axis. Alternatively or additionally, the superimposed movement may also include an oscillation of a nozzle about a horizontal axis.

[0041] According to a further exemplary embodiment, the device further comprises a suction device, which is provided or coupled to the outlet. According to a further exemplary embodiment, the suction device is designed to generate a negative pressure at the outlet.

The plant concerning the object of the invention is achieved by a plant for the additive production of workpieces, which is adapted to selectively solidify a powder in a powder bed of a chamber defining a space, and in layers, and with a device is provided for Entpulvern the space according to at least one of the aspects described herein.

It is understood that alternatively, the device for Entpulvern may also be designed separately from the manufacturing plant. In such a case, it is advantageous if the building chamber, which defines the installation space, preferably including the platform, which forms a floor of the installation space, can be removed from the production facility and fed to the device for removing powder. This has the advantage that the production plant can be used for a new production run during the deflaking process. Accordingly, it is advantageous if the building chamber is replaceable.

Furthermore, according to another exemplary embodiment, the device for removing powder can be connected to a device for recovering the powder in order to utilize the dissolved, unfixed powder for a further production process.

[0045] With regard to the method, the object of the invention is achieved by methods for decoupling a construction space of an installation for additive production, with the following steps:

Providing at least two lances movable relative to the powder bed, each being provided with at least one nozzle,

Supplying the nozzles to a powder bed in the construction space, in particular in an edge region adjacent to at least one component which is located in the powder bed,

Providing a pressurized gaseous fluid, Generating a directed gas flow for powder removal in the installation space using the at least two lances, which are offset in the flow direction to each other, the nozzles of the lances are aligned in the same direction in a circumferential direction to generate the directed gas flow, and

Removing the directed gas flow from the installation space.

Also in this way the object of the invention is completely solved.

Preferably, three or more lances are used with corresponding nozzles. According to an exemplary embodiment, the discharge of the gas flow takes place by suction through an outlet, preferably via a single outlet. According to a further exemplary embodiment, the lances can be supplied to the installation space from above.

[0048] In a further aspect of the present disclosure, a use of a device for powder removal in accordance with one of the aspects described herein for powder removal in a construction space of an installation for additive manufacturing, in particular a powder bed installation.

It is understood that the use of other systems for additive manufacturing is conceivable, based on different principles of action. This relates in particular to processes in which a powder bed is produced layer by layer, wherein a subset is solidified layer by layer by material input, heat input and / or energy input.

It is understood that the features of the invention mentioned above and those still to be explained below can be used not only in the respectively specified combination but also in other combinations or in isolation, without departing from the scope of the present invention. Further features and advantages of the invention will become apparent from the following description of several preferred embodiments with reference to the drawings. Show it:

1 shows a simplified schematic representation of an installation for additive production;

2 shows a simplified schematic representation of an apparatus for the removal of powder from a construction space;

3 is a simplified schematic representation of an embodiment of a

Device for dispelling, in a first state;

4 shows a further illustration of the device according to FIG. 3 in a second state;

5 shows a simplified schematic illustration of a further embodiment of a device for the removal of powder, in a first state;

FIG. 6 shows a further illustration of the device according to FIG. 5 in a second state; FIG.

7 shows a simplified schematic plan view of a construction space with an additively manufactured component for illustrating an arrangement for the removal of powder;

8 shows a further simplified schematic plan view of a construction space with an additively manufactured component for illustrating an arrangement for desulphurisation, for illustrating pivoting movements of the nozzles;

9 is a sequence of simplified schematic illustrations of a nozzle-equipped lance for illustrating a periodic vertical movement;

10 shows another sequence of simplified schematic representations of one with a

Nozzle provide lance for illustrating a pivotal movement of the nozzle;

11 shows a simplified schematic side view of a lance nozzle provided with a fan-shaped nozzle;

FIG. 12 shows a simplified schematic plan view of the arrangement according to FIG. 11 in a first state of the nozzle; FIG. 13 shows a simplified schematic plan view of the arrangement according to FIG. 11 in a second state of the nozzle;

FIG. 14 shows a simplified schematic plan view of the arrangement according to FIG. 11 in a third state of the nozzle; FIG.

15 shows another simplified schematic plan view of a nozzle arrangement for a lance, wherein the nozzle arrangement has two counter-oriented nozzles; and

16 shows a schematic block diagram for illustrating an embodiment of a method for decoupling a construction space of an installation for additive production.

[0052] FIG. 1 illustrates, with reference to a simplified schematic representation, an additive manufacturing plant, generally designated 10, which uses a powder bed. The plant 10 is exemplified as a so-called binder jetting plant or SLM plant (selective laser melting) designed. A colloquial term for such methods is 3D printing. Accordingly, the system 10 may be referred to simply as a 3D printer.

The term 3D printing generally refers to generative manufacturing processes in which workpieces are built up in layers. For this purpose, a powder layer is applied on a height-adjustable platform in a building chamber or in a space layer by layer and partially solidified, such as using a so-called binder. For this purpose, a kind of printhead is used, which is regularly moved in two dimensions and over which the binder is applied. The binder is required to selectively bind the powder. The layered structure and application of the binder is repeated layer by layer until the workpiece is completely finished. The workpiece is then still surrounded by loose powder. The powder residues are removed or the component is removed from the powder bed. Excess powder may be reused, for example, after processing (such as sifting) in a recovery plant. A similar process principle is based on the so-called selective laser melting (SLM). However, no binder is used there, instead energy is introduced into the powder via a laser beam in order to melt it locally and thus to connect it to the environment. Aspects and embodiments of the present disclosure can be used within the framework of binder jetting, in the context of SLM, but also in the context of further additive / generative production processes, which are based on the processing of a powder in the powder bed.

The system 10 shown in Fig. 1 comprises a housing 12 which houses components of the system 10. Only schematically, a control device 14 is indicated in Fig. 1. Via a control panel or control panel 16, a user can operate and control the system 10. It is also conceivable to control the system 10 via a computer coupled to the control device 14 or even via a mobile device.

In the housing 12 of the system 10, a storage chamber 22 and a construction chamber 24 are arranged by way of example. The storage chamber 22 and the construction chamber 24 have, for example - in plan view - a rectangular cross-section. In principle, a round or another polygonal cross-section is conceivable. In the storage chamber 22, a supply amount of a powder 28 is used, which is used in the additive manufacturing. The powder 28 is transferred between the storage chamber 22 and the building chamber 24. For this purpose, a so-called application roller 32 is arranged at a surface 30 of the powder 28. Alternatively, the use of a so-called squeegee is conceivable. The application roller 32 is movable in a horizontal direction between the storage chamber 22 and the construction chamber 24, compare the arrow 34. In the storage chamber 22 is further arranged via a drive 40 movable platform 38 is arranged, compare the arrow 42 to illustrate the direction of movement. By moving the platform 38, the level of the surface 30 of the powder 28 can be maintained.

The application roller 32 provides a layer structure on a surface 46 of a construction space 44 in the construction chamber 24. Thus, layer by layer loose powder is deposited in the construction chamber 24. The assembly chamber 24 is further assigned an application head 48, which is movable parallel to the surface 46 in one or two spatial directions, compare the arrows labeled 50. Through the application head 48, a binder can be applied to locally solidify or glue the powder. For the binder stocking 52 is provided. In this way, a workpiece or component 56 is formed layer by layer in the construction chamber 24. The component 56 is produced in a powder bed 58 in the installation space 44. The construction space 44 can have a round or angular cross-section (in plan view).

A platform 60, which can be moved vertically via a lifting drive 62, is also arranged in the building chamber 24, compare the arrow 64, which illustrates a direction of movement. For example, the system 10 is operated such that the platform 60 is lowered a little way down with each new layer structure. Conversely, the platform 38 is always raised a piece up when a layer has been removed and transferred from the storage chamber 22 into the building chamber 24.

After completion in the building chamber 24, the workpiece 56 is surrounded by loose excess powder. It goes without saying that further manufacturing steps can follow the shaping production in the construction chamber 24 in order to ensure the desired properties and / or the desired strength level of the component 56.

With reference to Fig. 2, a device for de-powdering, designated 100, is illustrated. The Entpulvern can also be referred to as depowdering. The device 100 may be formed as part of a manufacturing facility 10, see FIG. 1 for this purpose. However, it is also conceivable to carry out the device 100 separately from the installation 10. In both embodiments, the apparatus 100 is adapted to receive the build chamber 24 with the powder bed 58, wherein the powder bed 58, the component 56 (or a plurality of components) and excess powder is disposed.

The device 100 has a plurality of lances 102, 104. For example, two, three or four lances 102, 104 are provided. Depending on the size of the Building chamber 24 is also the use of a larger number of lances 102, 104 conceivable. The lances 102, 104 each carry at least one nozzle 1 12, 1 14. The lances 102, 104 and the nozzles 112, 114 serve for the application of a pressurized fluid, for example compressed air or an inert gas.

The lances 102, 104 project through a cover 122, which closes the construction chamber 24 in a sealed manner, compare, for example, a hinge denoted by 124 and a peripheral seal 126. The cover 122 can also be referred to as a cover. The lances 102, 104 are received on the cover 122.

To supply the lances 102, 104 and the nozzles 112, 114, a supply unit 130 is provided. By way of example, the delivery unit 130 comprises a pump or a pressure generator 132. The delivery unit 130 is coupled via a fluid line 134 to the lances 102, 104 and thus to the nozzles 112, 114 in order to lower them via the nozzles 12, 14 Apply pressurized gaseous fluid to dislodge the excess powder from the component 56 and carry it away. It is understood that the provision unit 130 may form part of the device 100, but is also conceivable separately from the device 100. At a minimum, the device 100 is configured to be coupled to such a pressurized fluid supply unit 130.

For handling the lances 102, 104, a handling unit 140 is provided. By way of example, the handling unit 140 comprises a drive 142 for the lance 102 and a drive 144 for the lance 104. It is conceivable to use a corresponding drive for each lance 102, 104 used. The actuators 142, 144 may provide at least one degree of freedom of movement for the lances 102, 104 and / or their nozzles 12, 14. These may be linear movements as well as rotational movements or pivoting movements.

The lances 102, 104 are configured such that a directional flow of fluid 150 results when the pressurized fluid from the nozzles 112, 14 of FIG Lances 102, 104 exits and dissolves the powder from the component 56. The directed fluid flow 150 is designed in particular as a circulating flow, circular flow and / or circular flow. Furthermore, a cyclone flow is conceivable. Preferably, the directional fluid flow adjusts in a peripheral area around the component or components 56. In the exemplary embodiment shown in FIG. 2, the fluid flow 150 spirals spirally in the direction of the cover 122. A cover opening or an outlet 162 is arranged in the cover 122. The outlet 162 is associated with a suction device 160. By way of example, the suction device 160 has a suction unit, which provides a negative pressure at the outlet 162. Via a line 164, the outlet 162 is connected to the suction device 160 or to its suction unit.

Further, in Fig. 2, a designated 170 control unit is indicated schematically. The control unit 170 is connected via control lines 172 to the drives 142, 144, the supply unit 130 and possibly also to the suction device 160 (in FIG. 2 no corresponding line is shown). In this way, the control unit 170 may control the device 100 to provide a desired regime or process for the powder removal.

The desired directed fluid flow, which is designed in particular as a circular flow, results from a suitable arrangement and alignment of the lances 102, 104 as well as their nozzles 112, 114. In this context, it should be noted that the illustrated orientation of the lances 102, 104 For reasons of illustration, nozzles 112, 114 in FIG. 2 do not necessarily correspond to a streamlined orientation.

With reference to FIGS. 3 and 4, and with additional reference to FIGS. 5 and 6, the process of deflaking is illustrated in more detail. FIGS. 3 and 4 illustrate two states during a first exemplary procedure for dissolving and removing excess powder from the powder bed 58. FIGS. 3 and 4 illustrate two states during a second exemplary procedure for dissolving and removing excess powder the powder bed 58. In Fig. 3 and Fig. 4, the outlet for discharging the fluid flow 150 is disposed in a side wall of the building chamber 24, see reference numeral 166. The alternative arrangement of the outlet 162 at the top in the region of the cover 122 is shown in Figs Fig. 4 only indicated by dashed lines. It is understood that the flow guidance takes place in such a way that the fluid flow containing the dissolved powder can be conducted as favorably as possible in the direction of the outlet 166.

Figures 3 and 4 illustrate an approach in which the platform 60 is not or not substantially vertically moved during deflaking. Instead, the lances 102, 104 are moved vertically via the drives 142, 144 in order to be able to follow the decreasing amount of powder in the powder bed 58.

FIGS. 5 and 6 illustrate an alternative approach in which the platform 60 on which the component 56 has been formed is moved via a lifting drive 62 in order to determine the relative movement between the lances 102, 104 and the (FIG. due to the erosion of decreasing) powder bed 58 bring about. In FIG. 5 and FIG. 6, the outlet 162 is again arranged in the cover 122. It is understood that a combination of the approaches pursued in FIGS. 3 and 4 as well as FIGS. 5 and 6 is also conceivable. However, it is advantageous if the vertically oriented lances 102, 104 can follow the removal of the powder bed 58.

The outlet 162 is funnel-shaped in this exemplary embodiment. By way of example, the outlet 162 is arranged in a center of the cover 122 and, with its conically open side, faces the installation space 44. In this way, the formation of the directed flow 150 is further supported. Preferably, a cyclonic flow results.

The decoupling may be directed to removing as much as possible of the excess powder from the installation space 44. Alternatively, a goal of the Entpulverns initially be to expose the component 56 so far that it can be removed manually or by machine. In the case of a plurality of components 56, the lances 102, 104 can also be arranged between individual components 56 in order to Spaces to be powdered. The nozzles 112, 114 can also demultipulate edges and / or corners of the tree space 44. In other words, the device 100 also allows cleaning of the installation space 44 if no component 56 is arranged therein.

Further, embodiments are also conceivable in which only a coarse Entpulvern takes place, which allows the removal of the component to make the construction chamber 24 usable again. Conversely, in alternative embodiments, this means that the component 56 can be subjected to further purification steps, for example, in order to remove residues of the excess powder.

With reference to FIG. 7, a conceivable arrangement of a plurality of lances 102, 104, 106, 108 with nozzles 1 12, 1 14, 16, 118 is illustrated by means of a schematically greatly simplified plan view of a construction chamber 24. The lances 102, 104, 106, 108 are arranged in a circle around a center of the building chamber 24, in which one or more manufactured components 56 are arranged. In Fig. 7, the lances 102, 104, 106, 108 thus have an angular offset of about 90 ° to each other. The nozzles 1 12, 1 14, 1 16, 1 18 are aligned approximately tangentially to the (imaginary) circle. The orientation of the nozzles 1 12, 1 14, 1 16, 1 18 also includes a same direction orientation of the respective outlet, for example in the counterclockwise direction. However, this is only to be understood as an exemplary embodiment. The arrangement of the lances 102, 104, 106, 108 and the nozzles 1 12, 1 14, 1 16, 1 18 in Fig. 7 allows an approximate circular flow 150, which is led to the outlet 166, to which optionally oppressive. It is understood that such a suction opening or such an outlet can also be arranged elsewhere, in particular in an upper region of the building chamber 24 in a cover. However, in Fig. 7, a lateral outlet 166 has been shown primarily for purposes of illustration. This is not meant to be limiting.

The arrangement and orientation of the nozzles 112, 114, 116, 118 in Fig. 7 causes a directed flow in which the nozzles 1 12, 1 14, 1 16, 1 18 "in series" are arranged. Thus, ideally, the desired fluid flow 150 may be maintained about the entire circumference or nearly the entire circumference around the component 56. The advantage of this flow control over an arbitrary flow With a plurality of randomly aligned nozzles, the result is that the excess powder can be removed faster and more efficiently.

Starting from the basic arrangement shown in FIG. 7, FIG. 8 illustrates a conceivable variation in which the nozzles 1 12, 1 14, 16, 18 are arranged about the longitudinal axis of the lances 102, 104, 106, 108 (in Fig. 8 perpendicular to the plane of view) oscillate, compare the designated 176 curved double arrows.

In general, it is conceivable, the beam guidance of the nozzles 112, 114, 116, 1 18 by movement of the nozzles 1 12, 1 14, 1 16, 1 18 to vary in order to improve the removal performance. This can be done in a coordinated manner for the lances 102, 104, 106, 108 in order to increase the effect. The conceivable manipulations may include a vertical movement of the lances 102, 104, 106, 108. Furthermore, pivoting of the nozzles 112, 114, 116, 118 about an axis perpendicular to the longitudinal axis of the lances 102, 104, 106, 108 is conceivable. In addition, a pivoting of the nozzles 1 12, 1 14, 1 16, 1 18 about the longitudinal axis of the lances 102, 104, 106, 108 is conceivable. These manipulations can be combined with each other to maximize the removal rate.

In addition, it is conceivable to coordinate or to synchronize the manipulations of the individual lances 102, 104, 106, 108 with their nozzles 1 12, 1 14, 1 16, 1 18. The lances 102, 104, 106, 108 can thus oscillate vertically synchronized, whereby a "phase shift" is conceivable, so that not all lances 102, 104, 106, 108 simultaneously reach their extreme positions. However, it is also conceivable to completely synchronize the vertical movement of the lances so that there is no "phase shift".

Furthermore, it is accordingly conceivable to synchronize the pivoting of the nozzles 112, 114, 116, 118 about the longitudinal axis of the lances of the lances 102, 104, 106, 108 and / or about the transverse axis to the longitudinal axis, with or without " Phase shift ". The phase shift can also be referred to as the phase difference. The different degrees of freedom of the conceivable manipulations can be combined with each other. FIG. 9 illustrates a periodically vertical movement of a lance 102 on which a nozzle 12 is arranged on the basis of a schematically greatly simplified embodiment. An arrow labeled 178 illustrates the timing. A double arrow labeled 180 illustrates the oscillating vertical motion. FIG. 9 accordingly shows extreme positions (up / down) of the lance 102.

10 illustrates a periodically pivoting movement of a nozzle 112, which is accommodated on a lance 102, on the basis of a schematically strongly agreed embodiment. An arrow labeled 178 illustrates the timing. An arrow designated 182 indicates the oscillatory pivoting movement.

[0083] FIG. 11 illustrates a side view of a lance 202, which carries a nozzle 212, in a schematically very simple form. FIGS. 12, 13 and 14 show various conceivable configurations of the nozzle 212 in plan view. The nozzle 212 has a plurality of outlet openings in the form of nozzle fingers 214, 216, 218. In Fig. 12, the nozzle fingers 214, 216, 218 are spread or fanned out, resulting in a combined opening cone with a considerable opening angle. In this way, a large area can be illuminated. In Fig. 13, the nozzle fingers 214, 216, 218 have a nearly parallel orientation. In Fig. 14, the nozzle fingers 214, 216, 218 are inclined towards each other, so that a strong focus of the combined fluid flow is given.

In exemplary embodiments, the nozzle fingers 214, 216, 218 are manipulatable so that transformation between the states shown in FIGS. 12, 13, and 14 is conceivable. Again, periodic transformations are conceivable. However, it is also conceivable to maintain one and the same setting of the nozzle fingers 214, 216, 218 during the procedure of the Abtpulverns. Furthermore, it is conceivable that the nozzle fingers 214, 216, 218 are adjustable (fixed in position).

Alternatively or additionally, it would also be conceivable to pivot the individual nozzle fingers 214, 216, 218 again about axes which are oriented transversely to the longitudinal axis of the lance 202. This is not explicitly shown in FIGS. 11 to 13. Fig. 15 shows in a plan view another alternative embodiment of a nozzle 222, which is arranged for example at a lower end of a lance. The nozzle 222 has two oppositely oriented nozzle fingers 224, 226. In the nozzle 222 shown in Fig. 15 also manipulations in the form of pivotal movements and possibly even a unidirectional rotational movement about a longitudinal axis of the lance (perpendicular to the plane view) are conceivable.

With reference to FIG. 16, an embodiment of a method for de-powdering a construction space of an apparatus for additive production is illustrated by means of a schematically greatly simplified block diagram. The method comprises a step S10, which comprises the provision of at least two lances, which are movable relative to a powder bed and each provided with at least one nozzle. By way of example, step S10 further comprises the provision of a cover for a building chamber enclosing the installation space, wherein the at least two lances are received in the cover and insertable into the building chamber.

This is followed by a step S12, which includes feeding the nozzles into the installation space in the direction of a powder bed, in which at least one additive-manufactured component and a loose powder quantity are arranged. Preferably, the lances are arranged with the nozzles in an edge region of the installation space, wherein the component or the plurality of components is arranged therebetween.

The method further comprises a step S14 involving providing a pressurized gaseous fluid. The fluid may be compressed air. However, it may also be a pressurized inert gas. Step S14 may include coupling respective ports or providing corresponding pressure generating units.

The method further comprises a step S16, which includes the generation of a directed gas flow for powder removal in the construction space. Directed gas flow can be achieved by appropriate alignment and orientation of the lances and from their nozzles cause. Finally, a circular flow or a circulating flow preferably results.

The method may further include an optional step S18 involving manipulations / variations of the flow guide. This may include, for example, a generation of a combined movement of the lances by combining a relative movement between the lances and a relative movement between the lances and the installation space. These may be vertical movements, pivoting movements, rotational movements and the like. Preferably, the movement manipulation / variation takes place periodically, with or without phase offset between the different lances or nozzles. Such coordinated oscillatory movements can increase the removal rate.

The method further comprises a step S20, which includes a discharge of the gas flow via an outlet from the installation space. The gas flow or fluid flow removes removed powder from the installation space. The fluid flow is preferably led out of the installation space via only a single outlet opening. The outlet opening is arranged, for example, in the cover of the installation space. In this way, the flow guidance can be such that a spiral (cyclonic) flow results in the installation space.

It is understood that at least the steps S16, S18 and S20 can run in parallel at least temporarily. Further, the method may include tracking the lances to follow the decreasing powder bed. The Nachführbewe- can be effected by actively moving the lances and / or by actively moving a platform in the space that carries the powder bed.

Claims

claims

Anspruch [en] An apparatus for decompressing a construction space (44) of a plant (10) for additive manufacturing, which comprises:

at least two lances (102, 104, 106, 108, 202) each provided with at least one nozzle (1 12, 1 14, 116, 118, 212, 222), the at least two lances (102, 104, 106 , 108, 202) are arranged adjacent to at least one additively manufactured component (56) at least in an operating position in the installation space (44),

a handling unit (140) for moving the at least two lances (102, 104, 106, 108, 202) relative to the installation space (44),

a supply unit (130) for supplying a pressurized gaseous fluid, and

an outlet (162; 166),

characterized,

in that a control unit (170) is provided, which is coupled to the at least two lances (102, 104, 106, 108; 202), the handling unit (140) and the supply unit (130) for their control, so that using the at least two lances (102, 104, 106, 108, 202) in the installation space (44) can be used to generate a directed gas flow for removing powder in order to discharge the gas flow via the outlet (162, 166), and

in that the nozzles (112, 114, 116, 118, 212, 222) of the at least two lances (102, 104, 106, 108, 202) are aligned in the same direction in a circumferential direction in order to generate the directed gas flow.

2. Apparatus according to claim 1, characterized by at least three vertically

oriented lances (102, 104, 106, 108, 202) which in an edge region in the construction space (44) are placed around at least one additively manufactured component (56).

3. A device according to claim 2, characterized in that the at least three vertically oriented lances (102, 104, 106, 108, 202) are placed in a circle around the component.

4. Apparatus according to claim 2 or 3, characterized in that the at least three vertically oriented lances (102, 104, 106, 108, 202) can be placed in a circle around the at least one additively manufactured component (56).

5. Device according to one of claims 1 to 4, characterized in that the lances (102, 104, 106, 108, 202) are arranged such that in a chamber (24), which defines the space (44) , a circular flow or circumferential flow around the at least one component (56) results.

6. Device according to one of claims 1 to 5, characterized in that the lances (102, 104, 106, 108, 202) and the outlet (162; 166) are arranged such that there is a cyclonic flow.

7. Device according to one of claims 1 to 6, characterized in that the nozzles (1 12, 1 14, 1 16, 1 18; 212; 222) are designed to eject the pressurized fluid directed.

8. Device according to one of claims 1 to 7, characterized in that a respective major axis of the nozzles (112, 1 14, 1 16, 1 18; 212; 222) has less than 30 ° deviation from the horizontal.

9. Device according to one of claims 1 to 8, characterized in that the nozzles (1 12, 1 14, 116, 118, 212, 222) have finger-shaped branches.

10. Device according to one of claims 1 to 9, characterized in that the lances (102, 104, 106, 108, 202) are vertically movable.

1 1. Device according to one of claims 1 to 10, characterized in that the lances (102, 104, 106, 108, 202) are pivotable about its longitudinal axis.

12. Device according to one of claims 1 to 11, characterized in that the nozzles (112, 114, 116, 118, 212, 222) are tiltable.

13. Device according to one of claims 1 to 12, characterized by a

Cover (122) for the installation space (44), wherein the at least two lances (102, 104, 106, 108, 202) are guided through the cover (122).

14. The device according to claim 13, characterized in that the outlet (162;

166) is disposed in the cover (122).

15. Device according to one of claims 1 to 14, characterized in that the control unit (170) is adapted to the lances (102, 104, 106, 108, 202) defined relative to a in the powder bed (58) arranged component (56 ).

16. The device according to claim 15, characterized in that the control unit (170) is adapted to track the lances (102, 104, 106, 108, 202) to a level of the powder bed (58).

17. Device according to one of claims 1 to 16, characterized in that the control unit (170) is adapted to drive the lances (102, 104, 106, 108, 202) coordinated, comprising at least matched vertical movements or pivotal movements.

18. Device according to one of claims 1 to 17, characterized in that the control unit (170) is adapted to move the lances (102, 104, 106, 108, 202) in opposite directions.

19. Device according to one of claims 1 to 18, characterized in that the control unit (170) is adapted to a relative movement between the lances (102, 104, 106, 108, 202) and a relative movement between the lancets (102 , 104, 106, 108, 202) and the installation space (44).

20. Device according to one of claims 1 to 19, characterized by a

Extraction device (160), which is provided or coupled to the outlet (162; 166), wherein the suction device (160) for generating a negative pressure at the outlet (162; 166) is formed.

21. Plant for the additive production of components (56) which is adapted to a powder in a powder bed (58) of a chamber (24) defining a space (44) defi ned selectively and in layers, characterized by a Vorrich - Device (100) according to any one of claims 1 to 20 for Entpulvern the installation space (44).

22. A method for decoupling a construction space (44) of an installation for additive production, comprising the following steps:

Providing at least two lances (102, 104, 106, 108, 202) which are movable relative to a powder bed (58) in the installation space (44) and which are each provided with at least one nozzle (1 12, 1 14, 1 16, 118; 212, 222) are provided,

Supplying the nozzles to a powder bed (58) in the installation space (44), in particular into an edge area adjacent to at least one component (56) which is located in the powder bed (58),

Providing a pressurized gaseous fluid,

Generation of a directed gas flow for powder removal in the installation space (44) using the at least two lances (102, 104, 106, 108; 202), which are offset from one another in a flow direction,

wherein the nozzles (112, 114, 116, 118; 212; 222) of the lances (102, 104, 106, 108; 202) are aligned in a circumferential direction to produce the directed gas flow, and Removing the directed gas flow from the installation space (44).

23. The method of claim 22, further comprising generating a combined movement of the lances (102, 104, 106, 108, 202) from a first relative movement between the lances (102, 104, 106, 108, 202) and a second relative - Movement between the lances (102, 104, 106, 108, 202) and the space (44).

24. Use of a device according to one of claims 1 to 20 for powder removal in a construction space (44) of a plant for additive production, in particular a powder bed plant.