DE102014005916A1 - Device for producing three-dimensional objects - Google Patents

Abstract

The invention relates to a device 1 for producing three-dimensional objects 2 by sequentially solidifying layers of a pulverulent building material 4 solidifiable by means of radiation 3 at the locations corresponding to the respective cross-section of the object 2, in particular SLS or SLM device with a housing 5, in which a process chamber 6, a building chamber 7 accommodated therein, in which a carrying device 8 for holding the object 2 with a height-adjustable support 9 is arranged, a coating device 12 for applying layers of the building material 4 to the carrying device 8 or a previously formed layer, a metering device 11 for feeding the building material 4 and an irradiation device 14 for irradiating layers of the building material 4 at the locations corresponding to the respective cross-section of the object 2, wherein the irradiation device comprises at least one movable scanner 17, wherein weni at least four scanners 17 are arranged and movable over the construction field 20 of the construction chamber 7 such that each position of the construction field 20 can be exposed to the radiation from at least three scanners simultaneously if necessary, to which the scanners from a basic position lying above the construction field individually, jointly, in pairs or in groups in an out-of-plane exposure demand position in the X-, and Y-direction substantially parallel to the construction field and / or variable in height to the construction field, in particular in the Z-direction are arranged movable.

Description

The invention / innovation relates to a device for producing three-dimensional objects by successively solidifying layers of a radiation-hardenable powdery building material at the locations corresponding to the respective cross-section of the object, in particular a selective laser sintering (SIS) or laser melting device (SLM) with the further features of the preamble of claim 1.

Such devices generally have a housing in which a process chamber is arranged. In the bottom of the process chamber an adjacent building chamber is provided, in which a carrying device for supporting an object is arranged with a height-adjustable support. A coater apparatus is for applying layers of the building material to the support or to a previously formed layer. The building material is stored in a metering device and is supplied to the coater.

In addition, an irradiation device is provided for irradiating layers of the building material in the process chamber, the layers being exposed at the locations corresponding to the respective cross section of the object. The irradiation device has a plurality of scanners.

Such a device is for example off DE 100 53 742 known. There, the scanner or scanners are mounted on a cross slide-like arrangement and can thus be moved over the construction field.

In the known device each scanner is associated with a laser light source.

The invention has the object of providing a device with the features of claim 1 in such a way that the solidification of a layer can be optimized, in particular accelerated. This object is solved by the characterizing features of claim 1. Advantageous subclaims emerge from the dependent claims 2-15, claim 16 describes a method that can be carried out with the device according to the invention.

As the core of the invention, it is considered to provide at least four scanners over the construction field of the construction chamber and thereby arrange and movable so that each point of the construction field can be exposed as needed with the radiation from at least two scanners, preferably three scanners simultaneously, including the Scanner from a above the construction field z. B. equally distributed basic position individually, together, in pairs or in groups in an off-center exposure demand position are movable. The traversability is designed so that the scanners in both the X and Y direction, d. H. can be moved substantially parallel to the construction field, but can also be moved as needed with respect to their height on the construction field, z. B. in the Z direction, d. H. at right angles to the construction field, whereby oblique Verfahrrichtungen the scanner are included, z. B. when a scanner is moved simultaneously in the X and / or Y direction and in the Z direction. This also includes that a travel axis for height adjustment on the construction field is basically arranged obliquely.

The invention is therefore based on the following idea:
In the basic position, the scanners are initially above the construction field z. B. evenly distributed, ie the at least four scanners are z. B. arranged centrally over four assigned to them quadrant of the construction field and can there fulfill their exposure task, if exposure activity in all four quadrants is required.

If, due to the component geometry, the exposure activity now shifts to three, two or even only one quadrant of the construction field, then the four scanners should either be displaceable together or in pairs so that they can be brought into a position where, for example, the scanners of the first, the second and third quadrants can reach exposure points in the fourth quadrant without having to work with beams that have too great an angular deviation from a vertical line to the construction field.

Once exposure is required in further quadrants, the scanners are moved individually, in pairs, in groups, or together in a different position, where they can reach the exposure sites without large angular deviations. If, for example, then exposed again in all four quadrants, then an equally distributed basic position to be preferred and each scanner operates exposure points in its associated quadrant. In addition, an additional height mobility of at least one scanner is advantageous.

By this device according to the invention in conjunction with the described approach, a significant acceleration of the construction process is achieved. Scanners that are not needed in their construction field sections can be removed from there and used as additional scanners in another quadrant together with at least one other scanner, possibly at locations that are relatively close to each other, if this makes sense for thermal reasons.

There are several possibilities with regard to the mounting and traversability of the scanners; z. B. it is conceivable that at least two of the at least four scanners always have the same distance and are movable together. This means that the scanners are mounted in pairs on a scanner carrier. The scanner carrier can then be moved separately. However, it is also possible for the at least four scanners to be arranged and moved together over the construction field, wherein the unconstrained basic position of the scanners is respectively assigned to a section of the construction field located centrally below them, ie to a quadrant in the case of four scanners.

In principle, it is possible to rotate each individual scanner or scanner carrier with a linear displacement in the X, Y and Z directions also about a vertical axis. This increases the degree of freedom of the scanner or the scanner mounted on a carrier and thus the possibilities of using the scanner in different areas of the construction field. In principle, it is also possible for the at least two scanner carriers to be mounted rotatably about a common axis of rotation and possibly also to be displaced in the X and Y directions. The same applies to only one scanner carrier for all (four) scanners, this also can be moved both in the X and Y directions as well as rotatable about a vertical axis. When talking about an X and Y direction, these are two coordinates which are freely definable over the construction field and define a substantially horizontal displacement of the scanners.

A further increase of the fields of application results when each in X / Y and Z-direction movable and / or rotatable about a vertical axis scanner (carrier) is additionally pivotable from a horizontal position into a tilted inclined position. Then z. B. several scanners are brought by tilting alone in an equidistant distance to a solidifying point on the construction field. An oblique incidence of the radiation on the construction field may also be advantageous in special cases.

Several scanners can be supplied with laser radiation from a common laser using appropriate beam splitting. The laser can then be mounted on the scanner carrier and moved with this and possibly pivoted. Of course, it is also possible to connect the scanners to the output of one or more lasers with optical fiber guides.

The maximum displacement of a scanner carrier should be dimensioned and controllable such that all scanners mounted on the scanner carrier have the same distance to an exposure point arranged in the edge region of the construction field. In other words, this means that a common scanner carrier is moved so that at least one of four scanners mounted thereon is moved so far that it is arranged in an area outside the construction field above it and from there virtually irradiates the edge region back onto the construction field ,

In a further development of the invention, it is advantageously possible to arrange even individual scanners on a total of displaceable scanner carrier with respect to their distance displaceable height adjustable or pivotable.

In a development of the invention, a method is protected which uses the device according to claim 1 and has the following method steps:
First, the distribution of the building material sections to be solidified on the construction field within the next layer or layers is determined, then a common displacement of multiple scanners or all scanners over a portion of the construction field, which has the highest density of building material sections to be consolidated such that the solidify Building material sections can be processed simultaneously by multiple scanners and then return the scanner in an over the construction field evenly distributed base position or a new shift position. In particular, the basic position is selected when subsequently to be solidified sections are distributed on the construction field, ie that at least one section to be solidified in each quadrant of the construction field is present when the building site scanners are assigned.

The invention is explained in more detail with reference to an embodiment in the drawing figures. These show:

1 a schematic device for the production of three-dimensional objects by successive solidification of layers according to the prior art;

2 a schematic plan view of a construction field with an overlying plate-like scanner carrier with four scanners in basic position and in a shifted exposure demand position;

3 a schematic plan view of a construction site with two scanner carriers with four scanners in basic position and in a shifted exposure demand position;

3a - 3c Views in which the two scanner carrier are shifted or pivoted in their longitudinal direction to each other.

4 a schematic representation of six scanners, which are mounted on three scanner carriers, wherein the scanner carrier in the X and Y directions are horizontally displaceable and additionally pivotable about a common pivot axis;

5 a schematic representation of a plate-like scanner carrier with four scanners, which is horizontally movable in the X and Y directions and also tilted in an inclined position.

In 1 Fig. 1 schematically shows a prior art device for producing three-dimensional objects 2 by successively solidifying layers of one by means of radiation 3 solidifiable powdery building material 4 at the respective cross section of the object 2 represented corresponding points, wherein the device 1 a housing 5 in which a process chamber 6 is arranged at the bottom process chamber 6 is a construction chamber 7 connected, in which a carrying device 8th with a height-adjustable support 9 is housed. On the carrier device 8th is located either directly or separately through a building board, not shown, the powdery building material 4 , The carrying device 8th includes a z. B. as a spindle 10 trained vertical drive, with which the carrier 9 can be raised and lowered.

The building material 4 is from one next to the building chamber 7 arranged metering device 11 by means of a coater device 12 Layer by layer applied to the support device or a previously formed layer in the region of the building chamber. For this purpose, the coater device 12 a horizontally movable coater blade 13 on top of the surface of the dosing device 11 building materials 4 picks up and transports to the left and in the area of the building chamber 7 as a layer deposits. It should be noted that other metering devices and coating devices are possible within the scope of the invention, for. As Siebbeschichter and the like., Which are fed from a metering device arranged above.

The consolidation of the building material 4 via an irradiation device, 14 the layers of building material 4 or melts and thereby solidified as a result of a melting and cooling process. The irradiation device 14 consists essentially of a laser 15 whose ray 16 via a scanner 17 With usually two moving mirrors is deflected and called radiation 3 against the surface of the building material 4 is steered.

In addition, a gas injection 18 provided with which a gas flow into the process chamber 6 is injected, and over the construction level 19 guided and on the opposite side of the process chamber 6 is sucked off.

The present invention particularly relates to the scanners 17 , their mobility and arrangement on scanner carriers.

In drawing figure 2 is a schematic plan view from above a construction field 20 the construction chamber 7 shown, with four scanners 17a - d together on a scanner carrier 24 are mounted, so that the scanner 17a - 17d essentially centrally over the quadrant assigned to you 26a - 26d are located. With reference number 22 is the scanner carrier 24 , which in the embodiment according to 2 has a plate-like shape, but may be arbitrary, z. B. in lattice construction, as a frame, as individual strips and the like. In the basic position, with reference numeral 23 an exposure demand position is shown in which the scanner carrier 24 procedure, so the scanners 17a - 17c z. B. easily and together a field to be exposed 27 can reach on the construction field. All four scanners 17 then can this area 27 edit, which increases the processing speed. It is of course possible that the area 27 is larger and has a plurality of individual sub-areas to be exposed, which are then exposed as needed by the scanners.

When moving the scanner carrier 24 from the basic position 22 in the exposure demand position 23 the center shifts 25 of the scanner carrier 24 in the position 25 ' in this case shown above the area to be exposed 27 lies.

Is for example in the quadrant 26b another area 27b To expose, it will be appropriate that the scanner carrier with its center 25 ' will move to a position slightly further to the right, so the scanner 17d in the area 27b can expose.

The position of the scanner carrier 24 is required, depending on the location of the areas to be exposed on the construction field 20 controlled.

In drawing figure 3 are four scanners 17a - 17d on two scanner carriers 24a - 24b arranged, the two scanner carrier 24a and 24b can in terms of their distance 30 they can be relocated, ie they can have a smaller distance 30 ' However, it is also possible that the two scanner carrier are moved in parallel, as in 3a is shown.

In addition, it should be noted that all scanner carriers 24 can also be arranged rotatable about a vertical axis, ie, for example, the scan support 24a and 24b can take a position as they are in 3b is shown.

In principle, it is also possible that the scanner carrier 24a to cross in whole or in part, as in 3c is shown. These can be the scanner carrier 24a and 24b be arranged in slightly different levels in the space.

To the 3 It should be noted that the scanner carrier 24a and 24b with the scanners thereon 17a - 17d Both in the X and in the Y direction can be moved horizontally above the site as well as can be rotated around their axes of rotation. In addition, it is within the scope of the invention to pivot the scanner carrier out of the horizontal, so that the scanner in one area 17 can be brought into an optimal position.

In 4 are scanner carriers 24a . 24b and 24c shown, the z. B. on a common axis of rotation in its center 25 are arranged. Of course, the center can also be moved with the common axis of rotation in the X and Y directions. Of course, the center can be moved with the common axis of rotation in the X and Y directions. A pivoting of these three illustrated scanner carrier is possible. Of course, it is also within the scope of the invention to arrange only two scanner carrier on a common axis of rotation and to move together in the X and Y directions.

In 5 is still shown as a plate-like scanner carrier 24 can be moved in both the X and Y direction, including the crossing arrows at the center 25 of the scanner carrier 24 are shown. In addition, the scanner carrier 24 be pivoted from the horizontal position shown in an inclined position, for example by tilting about an axis 40 the scanner carrier, so that the scanner carrier with respect to the horizontal position forms an angle α. Additionally or alternatively, it is also possible for the scanner carrier to be around an axis 41 to tilt, which, however, in drawing figure 5 only hinted but not shown in detail. By tilting around the axis 40 All four scanners can be in a substantially equidistant distance to an area 27 on the construction field 20 be brought without the scanner carrier 24 to move in the horizontal direction. Such an inclination can be favorable in special cases, as quickly as possible critical areas 27 can be achieved on the construction field, also can be optimized by an oblique incidence, a Nachbelichtungsvorgang, for example, to smooth a surface, if z. B. already taken the powder.

Basically it is possible to use the laser 15 on a scanner carrier 24 to install, so that the beam guidance to the scanners 17a - 17d can be performed with high precision.

The invention is not limited to four scanners, but also includes a larger number of scanners that can be mounted on a larger number of scanner carriers than shown in the drawing figures. Significant for the invention is that in a basic position equally distributed scanner can be moved out of this basic position and, if necessary, in pairs of three or four in a larger majority there on the construction field can be used where they are currently needed for acceleration and intensification of the construction process , An optimization of the position of the majority of scanners over the construction field is calculated depending on how the areas to be exposed 27 are distributed on the construction field. By displacement and / or displacement or pivoting of the scanner carrier each other or about a horizontal axis, the scanner can be optimally positioned in position, so that significantly accelerates the construction process when selecting a multi-scanner exposure strategy.

LIST OF REFERENCE NUMBERS

1

contraption

2

object

3

radiation

4

building materials

5

casing

6

process chamber

7

Construction Chamber

8th

carrying device

9

carrier

10

spindle

11

metering

12

Beschichtervorrichtung

13

application blade

14

irradiator

15

laser

16

beam

17

scanner

18

gas injection

20

Baufeld

22

basic position

23

Exposure required position

24

scan support

25

center

26

quadrant

27

Area

30

distance

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10053742 [0004]

Claims (16)

Contraption ( 1 ) for producing three-dimensional objects ( 2 ) by successively solidifying layers of one by means of radiation ( 3 ) solidifiable powdery building material ( 4 ) at the respective cross section of the object ( 2 ), in particular SLS or SLM device, comprising - a housing ( 5 ), in which a process chamber ( 6 ), - a building chamber housed therein ( 7 ) in which a carrying device ( 8th ) to the day of the object ( 2 ) with a height-adjustable support ( 9 ), - a coating device ( 12 ) for applying layers of the building material ( 4 ) on the carrying device ( 8th ) or a previously formed layer, - a metering device ( 11 ) for supplying the building material ( 4 ) and - an irradiation device ( 14 ) for irradiating layers of the building material ( 4 ) at the respective cross section of the object ( 2 ), wherein the irradiation device comprises at least one movable scanner ( 17 ), characterized in that at least four scanners ( 17 ) above the construction field ( 20 ) of the building chamber ( 7 ) are arranged and moved such that each point of the construction field ( 20 ), if necessary, with the radiation from at least three scanners simultaneously exposable, including the scanner from a lying above the building site basic position individually, together, in pairs or in groups in an outdoor exposure demand position in the X and Y direction substantially parallel to the building field and / or variable in height to the construction field, in particular arranged to be movable in the Z direction. Device according to claim 1, characterized in that at least two of the at least four scanners ( 17 ) have a constant distance and are movable together. Device according to claim 1 or 2, characterized in that the at least four scanners ( 17 ) can be moved together over the construction field ( 20 ) are arranged. Device according to one of claims 1-3, characterized in that the at least four scanners ( 17 ) in the unprocessed basic position in each case a centrally located section of the construction field ( 20 ) assigned. Device according to one of the preceding claims, characterized in that the at least four scanners ( 17 ) on at least two separate scanner carriers ( 24 ) are arranged. Apparatus according to claim 5, characterized in that the at least two scanner carrier ( 24 ) are mutually movable. Apparatus according to claim 5 or 6, characterized in that the least two scanner carrier ( 24 ) are mounted on axes of rotation and can be moved by rotation. Apparatus according to claim 5 or 6, characterized in that the at least two scanner carrier ( 24 ) are both about a common axis of rotation rotatable and movable in the X / Y direction. Device according to one of the preceding claims, characterized in that all the scanners ( 17 ) on a common scanner carrier ( 24 ) are arranged. Device according to one of the preceding claims, characterized in that the at least one scanner carrier ( 24 ) Is mounted both in the XY direction movable and rotatable about a vertical axis. Device according to one of the preceding claims, characterized in that each movable and / or rotatable about a vertical axis scanner carrier ( 24 ) is additionally pivotable from a horizontal position in a tilted inclination. Device according to one of the preceding claims, characterized in that the plurality of scanners ( 17 ) from a common laser ( 15 ) are supplied with laser radiation. Device according to one of the preceding claims, characterized in that the laser ( 15 ) on the scanner carrier ( 24 ) is mounted and with this movable and optionally pivotable. Device according to one of the preceding claims, characterized in that the maximum displacement of a scanner carrier ( 24 ) is controllable so that all on the scanner carrier ( 24 ) mounted scanner ( 17 ) to a in an edge region of the construction field ( 20 ) have the same distance. Device according to one of the preceding claims, characterized in that individual scanners ( 17 ) on a total of displaceable scanner carrier ( 24 ) are arranged with respect to each other with respect to their displaceable displaceable, rotatable or pivotable. Method for producing three-dimensional objects by successively solidifying layers of a radiation-hardenable powdery building material at the locations corresponding to the respective cross section of the object using a device according to claim 1, characterized by the following method steps: determining the distribution of the building material sections to be solidified on the construction field ( 20 ), - common movement of multiple scanners ( 17 ) over a section of the construction field ( 20 ), which has the greatest density of building material sections to be consolidated such that the building material sections to be consolidated are simultaneously exposed by a plurality of scanners ( 17 ) are editable and - if necessary, return the scanner ( 17 ) in one above the construction field ( 30 ) in particular evenly distributed basic position in the event that subsequently to be consolidated sections on the construction field ( 20 ) are arranged distributed.

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