DE202013011396U1 - Generative production facility - Google Patents

Abstract

Generative manufacturing facility for layer-by-layer additive manufacturing of three-dimensional objects, with at least one manufacturing base (2) and at least one manufacturing head (3, 4, 4 ') for the location-selective arrangement of granulated, powdery or liquid manufacturing material on the manufacturing base (2) or on the manufacturing base (2) previously produced material layers, which comprises at least one fixing unit (24, 24-1, 24-2) for melting production material, the production base (2) and the production head (3) both corresponding to a working direction (5) in the plane a layer, as well as in a feed direction (7) relative to the thickness of the layers, so that the manufacturing head (3, 4, 4 ') is designed in such a way that the manufacturing material has a predetermined production pattern for the respective layer location-selectively exposed photoconductor (11) aufnehmba r and can be transported to the production site, the production head (3, 4, 4 ') having the following features for this purpose: - an electrophotographic image drum (8) which carries a photoconductor (11) on its jacket and in the area of a material transfer (12) the manufacturing head (3) is exposed relative to the manufacturing base (2), - at least one electrical conditioning unit (13) for electrostatically charging the photoconductor (11) of the image drum (8), - at least one of the conditioning unit (13) in the working direction (10) of the Imaging drum (8) subsequently arranged exposure unit (14, 14-1, 14-2), which comprises means for the location-selective exposure of the photoconductor (11) of the image drum (8), - at least one of the exposure unit (14, 14-1, 14- 2) in the working direction of rotation (10) of the image drum (8) arranged downstream developer unit (18, 18-1, 18-2) with at least one electrostatically chargeable transfer roller (19-1, 19-2, 19-3, 19-4) Provision of manufacturing m aterial, which is arranged parallel to the image drum (8), - at least one electrical document conditioning (22, 22-1) arranged in the working direction of rotation (10) of the image drum (8) before the material transfer (12) and acting in the direction of the production document (2), 22-2).

Description

The invention relates to a generative manufacturing device for layerwise additive production of three-dimensional objects according to the preamble of claim 1.

Generative manufacturing is a comprehensive term for the production of three-dimensional objects such as models, patterns, prototypes or tools. Production takes place directly on the basis of given data models. The computer representation of the object to be manufactured can be generated, for example, with the aid of a computer by means of CAD software. The computer analyzes the presentation and generates a height layer plan of the object to be produced, in which a production grid can be generated for each layer, from which it is apparent to which cells of the grid site-selective production material is to be stored and solidified. In this way, the generative manufacturing device builds up the three-dimensional workpiece in layers. Such manufacturing processes are also known by the generic term "rapid prototyping". Rapid prototyping manufacturing processes convert existing design information directly and quickly into workpieces, if possible without detours or molds. Instead of prototypes, of course, other objects such as tools or finished parts can be produced, with the additive manufacturing of tools being referred to as "rapid tooling" and the additive manufacturing of tools as "rapid manufacturing". However, common to all methods is the production of three-dimensional objects according to existing design information, such as CAD data.

Various generative manufacturing methods are known with which different materials can be processed at different production speeds.

In principle, the production facilities for the generative production of three-dimensional objects have at least one production head for arranging production material on a production base or on the production base previously produced material layers. The production underlay, on which the three-dimensional object is built up in layers, and the at least one production head are arranged so as to be displaceable relative to one another both in the working direction in the plane of a layer and in the feed direction relative to the thickness of the layers. For example, the production head can be moved in web form over a production base which is immovable in the plane of the layer to deposit material each time the production site is passed over.

The generative production device further comprises a fixing unit for fastening the stored or arranged production material to the already deposited material layers.

Selective laser sintering is a process for producing three-dimensional objects by sintering from a powdery production material. The production material is applied in a thin powder bed on the production base or the underlying already deposited material layers. A fixing unit, which is usually a laser, locally warms up the production material in accordance with the predetermined manufacturing information, so that at the specific locations the production material is sintered and converted into a solid state. The production material is a powder which is mixed with one or more sintered components, so that after melting by the fixing unit and cooling the melt, a solid material is formed. Therefore, a generative manufacturing facility for laser sintering can not process pure materials, since basically a sintered mixture is solidified. In addition, the operation is comparatively slow, since after the melting and sintering a cooling of the just-processed material layer must be awaited before the powder bed for the next layer of material can be applied.

If workpieces are made of a pure material, that is, without a binder, the production material powder, for example a metal powder, is completely melted. Such production facilities with correspondingly strong lasers are assigned to the selective laser melting.

As an alternative to the generative manufacturing process, which work in the core with locally selective melting of powdery material in a powder bed, a generative manufacturing method similar to the operating principle of an inkjet printer under the name "multi-jet modeling" or "poly-jet modeling" is known. In this case, a print head has a plurality of linearly arranged nozzles. The multi-jet manufacturing facilities process meltable plastics, especially hard waxes or wax-like thermoplastics, and can produce very fine droplets. You achieve high surface qualities. However, the production head of the poly-jet production facility has to travel long distances motor-driven and works only occasionally on the workpiece, so that the achievable production speeds may indeed be sufficient for the production of prototypes or models ("rapid prototyping") however, for industrial applications with series or mass production.

The present invention has for its object to provide a generative manufacturing device of the generic type, which ensures a fast and accurate layered production of three-dimensional workpieces with the possibility of processing multiple materials.

This object is achieved by a generative manufacturing device with the features of claim 1.

According to the invention, such a construction of the at least one production head is provided that the production material can be picked up in a location-selective way according to the principle of electrophotography and can be transported to the production underlay. The working principle of electrophotography is known for example from the application in two-dimensional laser printers. The invention has recognized that a considerably higher production speed can be achieved with the greatest possible accuracy by the working principle of electrophotography. Compared to selective laser melting, a significantly higher production speed is given since the production material does not have to be heated layer by layer. Furthermore, the loss of production material is significantly reduced, in particular in the case of various production materials, since no contamination occurs.

The production head of the manufacturing device according to the invention has an electrophotographic image drum, which carries a photoconductor on its jacket and is exposed in the region of a material transfer of the production head relative to the production underlay. The image drum is a rotatably mounted component which extends in its axial direction transversely to the working direction of the production head. During operation of the production device, the image drum is moved in a working direction of rotation and rolled over the production document. In this case, location-selective, small amounts of material are transported to the production site and stored there, which are previously placed on the photoconductor of the image drum on the principle of electrophotography. The production document 2 is a substantially horizontal device of the manufacturing facility, on which the three-dimensional object is built up layer by layer and solidification of manufacturing material. Advantageously, the worktable of the production facility forms the production base. In an embodiment of the inventive generative production device configured for series or mass production, a belt conveyor forms the production base on which further production locations for the layer-by-layer additive construction of three-dimensional objects can be moved into the working area of the production heads.

The manufacturing device also has an electrical conditioning device for the electrostatic charging of the photoconductor of the image drum and at least one exposure unit. In this case, the exposure unit comprises means for the location-selective exposure of the photoconductor of the image drum in accordance with the predetermined manufacturing information for the three-dimensional object or product. The exposure unit is arranged downstream in the working direction of rotation of the image drum of the electrical conditioning unit. During operation of the production device, the conditioning unit electrostatically charges the section of the image drum facing it. For this purpose, the conditioning device advantageously comprises corona wires, that is, thin wires mounted near the picture drum, which wires are put under high voltage and generate a corona discharge. In an alternative embodiment of the invention, the conditioning device comprises a series of point charging diodes, which are arranged parallel to the axial direction of the image drum and electrostatically charge the respectively facing surface line of the photoconductor. The point charging diodes are those diodes whose emission is sufficient for local ionization or electrostatic charging. Several side by side arranged in a row point charging diodes thus act together on a surface line of the photoconductor. If the image drum is rotated further, the respective following surface line is electrostatically charged.

After conditioning the photoconductor, the exposure unit exposes the photoconductor in accordance with the specified manufacturing information. In this case, in an advantageous embodiment, the exposure can be deleted at the points at which later production material is to be applied to the image drum. At the exposed areas of the photoconductor becomes conductive and thereby loses its charge. In an alternative embodiment, the exposure unit exposes a negative print image, with those locations being exposed in a location-selective manner, which are later to receive no production material.

The production head further comprises a developer unit arranged downstream of the exposure unit in the working direction of rotation of the image drum, which unit comprises at least one electrostatically chargeable transfer roller for the provision of production material. The at least one transfer roller is arranged parallel to the image drum. Each transfer roller supplies, via electrostatic forces, quantities of production material at its jacket to an opposition position at which the jacket of the image drum and the jacket of the transfer roller lie in the shortest distance from one another. In this opposition situation, production material is transferred from the transfer roller to the image drum at those parts of the image drum which were not previously exposed by the exposure unit. In one embodiment of the invention, the exposure unit produces a positive print image on the photoconductor whereby the fabrication material on the transfer roller is negatively ionized. In one embodiment with negative print imaging, the manufacturing material is positively ionized.

Finally, the production head according to the invention comprises an electrical underlay conditioning arranged in working direction of rotation of the image drum prior to material transfer to the production underlay and acting in the direction of the production underlay. The pad conditioning comprises in an advantageous embodiment of the invention corona wires. In a further embodiment of the invention, the underlay conditioning comprises a series of point charging diodes, which are arranged transversely to the working direction of the production head and are activated when passing over the construction site or the material layers already deposited on the production support at the production location. The electrical charge which generates the pad conditioning is greater in magnitude than the charge of the photoconductor on the image drum, so that in the opposition position of the image drum at the material transfer the entrained on the image drum amounts of material from the image drum are released and at the intended production on the production base or the material layers already deposited on it are transferred.

In an advantageous embodiment of the invention, the conditioning unit associated with the image drum and / or the base conditioning are formed either to produce a negative electrostatic charge or to generate a positive electrostatic charge. As a result, the number of processable via the principle of electrophotographic transport and fixation in the respective layer materials is significantly expanded. The conditioning unit and / or the base conditioning are set for a polarity of the electrostatic charge, which corresponds best to the selected manufacturing material. Advantageously conditioning unit and / or the pad conditioning between a setting for generating a negative electrostatic charge and a setting for generating a positive electrostatic charge are switched switchable.

In the already mentioned embodiment of the invention with production of a positive print image on the photoconductor and negative ionization of the production material on the transfer roller, the underlay conditioning is designed and adjusted such that a positive charge can be generated.

In the embodiment of the invention with generation of a negative print image on the photoconductor and negative ionization of the production material on the transfer roll, the underpack conditioning is designed and adjusted such that a negative charge can be generated. In both embodiments, the pad conditionings are configured such that an amount of electrical charge that can be generated by the pad conditioning is greater than an amount of photoconductor charge that can be generated by the conditioning unit at the periphery of the image drum such that the site-selective transfer of the fabrication material from the imaging drum to the manufacturing pad or the already stored on the production document material layers of the workpiece is guaranteed.

In a preferred embodiment of the invention, the exposure unit comprises as means for the location-selective exposure of the photoconductor of the image drum a laser, in particular a pulsed laser such as a CO2 laser, and a deflecting device associated with the laser. The optical deflection device is preferably a rotating mirror, in particular a hexagonal mirror, which directs the laser beam of the laser line by line on the image drum in the manner of a laser scanner. The laser is turned on and off according to the given manufacturing grids for the respective layer. Due to the exposure of the photoconductor by means of a laser very high production speeds can be achieved, so that the manufacturing device according to the invention is not only suitable for the production of prototypes, but also suitable for industrial series or mass production.

In an alternative embodiment, the exposure unit as a means for the location-selective exposure of the photoconductor of the image drum in the axial direction of the image drum to each other lined up light sources. The individual light sources are selectively controllable, according to the predetermined manufacturing grids, so that on the photoconductor, the desired print image before the assembly of the photoconductor on the developer unit can be generated. The selectively controllable light sources are preferably light emitting diodes.

In order to ensure ionization of the building material on the transfer roller, the transfer roller is associated with a loading unit. The charging unit generates electrostatic forces on the jacket of the transfer roller, which hold production material during transport to the image drum.

Advantageously, a cleaning unit is arranged in a return section of the image drum between the material transfer of the image drum and the conditioning unit. The cleaning unit is advantageously a Materialabstreifer, which is arranged with the smallest possible gap on the jacket of the image drum, so that any remaining material remnants are removed from the circumference of the rotating image drum. After the transfer of the production material from the image drum onto the production base or the material layers already fabricated thereon, residual material may still remain on the surface of the image drum, which is cleaned during the return to the conditioning unit where the image drum is conditioned for the next work cycle.

In a preferred embodiment of the invention, the developer unit comprises a plurality of transfer rollers for each different production materials, which are held on a rotatable transfer carousel such that in each case a transfer roller is movable to an active position adjacent to the image drum. The transfer carousel is adjustable by means of a drive in the manner of a revolver in steps. In this way, objects can be manufactured with different materials, wherein also within a layer, namely by brief rotation of the transfer carousel different materials can be installed. It is also the formation of alloys possible.

Advantageously, the production head for a first working direction on a first equipment with at least one conditioning unit, exposure unit, developer unit, pad conditioning and fixing on and for a first working device opposite second working direction on a second equipment. Accordingly, the second equipment respectively comprises at least one conditioning unit, an exposure unit, a development unit, a base conditioning unit and a fixing unit, which is arranged substantially symmetrically with respect to the first equipment. In this way, the operating speed is doubled, in which, after completion of a processing cycle, the working movement of the production head in the plane of the layers is changed and the direction of rotation of the image drum is also changed. The first equipment and the second equipment can be activated alternatively, with the respective operating directions of rotation of the image drum are opposite.

A rapid and accurate attachment of the production material on the production base or already deposited layers of material is given if the fixing unit of the production head comprises a laser and the laser associated with, optical deflection. The deflection device is preferably a rotating mirror, in particular a hexagonal mirror, which deflects the laser beam of the laser onto the points to be fixed in the manner of a laser scanner. In this case, the laser beam heats the locally selectively controlled points and melts the production material located there, which then cools and becomes part of the workpiece to be manufactured. In this case, pure material objects can be produced if unmixed production material, for example a metal powder, is deposited and melted by the laser beam.

If the image drum is assigned a heating device, then the production material is heated prior to transfer to the production base and thus the energy required for the melting process is reduced as part of the fixation. Advantageously, the image drum is held by the heater at a substantially constant temperature level, wherein the temperature level is advantageously adjustable.

In a further advantageous embodiment of the invention, the production device comprises at least one production head as a main production head for the production material and another production head as a support production head for support material, which is controlled in coordination with the main production head. The support manufacturing head arranges support material within the respective material layers to be produced, which is provided to support the respective subsequent material layer. The support material allows the formation of undercuts and the like. The support material is removed after the production of the three-dimensional object, for example by a water rinse.

Advantageously, the support manufacturing head corresponds to the main production head with respect to the arrangement of imaging drum, conditioning unit, exposure unit, developer unit and pad conditioning. The support production head operates at a similar operating speed as the main production head, so that overall a high operating speed is given. The fixing unit of the support production head is advantageously a heat source, for example an ultraviolet lamp.

In one embodiment of the invention, the fuser unit of the main manufacturing head is provided with a heat source, for example one or more ultraviolet lamps, instead of a melting device, for example a laser. As a result, certain production materials, which, for example, are applied in liquid form or are polymerized for solidification, can be fixed.

Further features emerge from the subclaims. The invention is explained below with reference to the drawing. Show it:

1 a perspective view of a first embodiment of a generative manufacturing facility,

2 a perspective view of a second embodiment of a generative manufacturing device,

3 a cross section of an embodiment of a main manufacturing head for a generative manufacturing device according to 1 or 2 .

4 a cross section of an embodiment of a support manufacturing head for a generative manufacturing device according to 1 or 2 .

5 a cross-section of another embodiment of a main manufacturing head for a generative manufacturing device according to 1 or 2 .

6 a cross-section of another embodiment of a support manufacturing head for a generative manufacturing device according to 1 or 2 ,

1 shows a simplified representation of a generative manufacturing facility 1 for the layerwise additive production of three-dimensional objects. In this context, an additive manufacturing means that production material is on a production document 2 the manufacturing facility 1 is accumulated. The production document 2 is the substantially horizontal worktable of the manufacturing facility, on which the three-dimensional object is built up by depositing and solidifying manufacturing material in layers.

The manufacturing facility 1 includes at least one production head 3 . 4 for the location-selective arrangement of production material on the production document 2 , In the exemplary embodiment shown, the production device comprises a main production head 3 for the location-selective arrangement of production material and a support production head 4 for arranging supporting material which is applied during production for supporting the material layers to be subsequently applied and is removed after the completion of the production of the workpiece. The support material allows the simple and accurate production of undercuts.

The production heads 3 . 4 are according to a working direction 5 in the level of a shift or a level of the production document 2 movably arranged. The production heads 3 . 4 become in operation of the manufacturing facility 1 above the production document 2 moved back and forth, taking material within a workspace 6 can be arranged on the production document or on it already deposited material layers. The main production head 3 and the support manufacturing head 4 are coordinated via the production document 2 driven, what in the presentation by the connection through a rigid frame 9 is symbolized. The production heads 3 . 4 can be housed in the manufacturing facility in a common housing.

The production heads 3 . 4 and the production documents are on the one hand in the working direction 5 slidably disposed relative to each other. On the other hand, the production document 2 and the manufacturing heads 3 . 4 in a feed direction 7 relative to the thickness of the layers against each other slidably disposed. In this way, after each working cycle, that is, the application of a material layer, the distance between the production heads 3 . 4 and the production document 2 increased by the amount of a layer thickness. Before each operation of the production heads 3 . 4 is thus the distance between the production heads 3 . 4 and the respective upper layer of material of the still unfinished three-dimensional workpiece on the production base 2 always the same.

In the embodiment shown, the working movement in the working direction 5 by a movement of the manufacturing heads 3 . 4 above the production document 2 realized. The production document 2 is in the feed direction 7 adjustable and movable. In further, not shown embodiments, the relative movement between the production heads 3 . 4 and the production document 2 in the feed direction 7 through the manufacturing heads 3 . 4 executed. In a further, not shown, embodiment, the manufacturing document 2 in working direction 5 movable while the manufacturing heads 3 . 4 are fixed.

The production heads 3 . 4 are designed to locate production material locally selective on the production document or the material layers already deposited thereon. In this case, the location-selective arrangement means that a production grid is specified for each material layer of the object to be manufactured, in which the locations provided for depositing production material or, in the case of the support production head, the locations provided for depositing support material are designated, and the material on the such predetermined locations is arranged. The production grids are determined by a control unit, not shown, on the basis of predetermined design data, for example from a CAD software, and the production heads 3 . 4 from driven according to a control unit, not shown.

Every production head 3 . 4 has at least one illustrated below in more detail image drum 8th on, which can be equipped on its circumference according to the given production grids with production or support material and during the working movement on the production document 2 be passed. In each case the generatrix of the picture drums 8th , which in opposition to the production document 2 lie, give production or support material to the production document 2 or the material layers already deposited thereon.

The invention is not on manufacturing equipment with main production heads 3 and support manufacturing heads 4 limited. In further embodiments, a single main production head or a plurality of main production heads are arranged so that different production materials can be used.

Another preferred embodiment of a manufacturing device according to the invention 1' is in 2 shown. The manufacturing facility 1' corresponds in its construction except for the differences explained below the structure of the manufacturing facility 1 according to 1 , For identical components, the same reference numerals are used.

The manufacturing facility 1' according to 2 has a main production head 3 and two support production heads 4 . 4 ' on which both sides of the main production head 3 on the frame 9 are attached. The working movement of the main production head 3 is thus above the frame 9 with the working movement of the support manufacturing heads 4 . 4 ' coupled so that all manufacturing heads 3 . 4 . 4 ' synchronously the workspace 6 sprinkle. The manufacturing heads are designed to work in both directions 5 , that is, in opposite directions of the working movement to be able to apply material, as described below with reference to 4 and 6 is described. As a result, production and support material is deposited on the production base or the material layers already deposited thereon in each working movement, so that a doubling of the production speed of the production facility 1' given is. At the end of a work movement, the working direction 5 changed and the production heads 3 . 4 . 4 ' moved in the opposite direction.

3 shows a cross section of a main production head 3 , which works in one direction 5 is working. The main production head 3 is doing in the direction of work 5 relative to the production document 2 emotional. The picture drum 8th is in a working direction 10 movable, the rotational speed of the image drum 8th with the working movement in working direction 5 is synchronized so that the image drum 8th above the production document 2 has passed.

The main production head 3 is formed such that the production material via a location according to the given manufacturing grids for the respective layer photoconductively exposed photoconductor 11 receivable and to the manufacturing location, that is transportable to the production document. The site-selective application of production material on the production document 2 or the material layers already deposited thereon 12 takes place according to the principle of electrophotography. In the embodiment shown, the image drum 8th with a photoconductor 11 , that is, a photoelectrically active material, coated. The picture drum 8th is in a housing 40 of the production head 3 in working direction 10 rotatably arranged and is in the range of a material transfer 12 opposite the production document 2 free. The material transfer 12 is a free passage in the housing 40 , The main production head 3 is with his case 40 and thus the picture drum 8th as well as all other facilities of the production head 3 in the manner of a carriage relative to the production document 2 ( 1 ) translationally movable.

The main production head 3 also has an electrical conditioning unit 13 for electrostatic charging of the photoconductor 11 the picture drum 8th and an exposure unit 14 on. The exposure unit 14 comprises means for the location-selective exposure of the photoconductor 11 the picture drum 8th , The conditioning unit 13 , which may also be referred to as a corotron, generated at the photoconductor 11 an electrostatic charge in the direction of the generatrix, that is, parallel to the axis of rotation of the image drum 8th and in opposition to the conditioning unit 13 lying section of the image drum 8th , The conditioning unit 13 can be designed as a corotron with so-called corona wires. In further embodiments, one is in the axial direction of the image drum 8th arranged line provided by point charging diodes.

The exposure unit 14 is working direction 10 the conditioning unit 13 downstream and has means for the location-selective exposure of the photoconductor 11 the picture drum 8th on. By this is to be understood that the exposure unit according to the given manufacturing grids by optical action individual points, that is location-selective, the facing surface line of the photoconductor 11 exposed and thereby neutralized the electric charge. In the exemplary embodiment shown, the exposure unit comprises 14 as a means for the location-selective exposure of the photoconductor 11 the image drum a laser 15 and one to the laser 15 assigned optical Deflection. The deflection is as a rotating deflection mirror 15 executed. The deflection mirror 15 is constantly kept in circulation by a drive unit, not shown, whereby the laser beam 17 the laser 15 like a laser scanner on the photoconductor 11 is moved back and forth. In the process, the laser becomes 15 switched on and off according to the predetermined manufacturing grids of the control unit, not shown, so that on the photoconductor 11 a printed image is generated with neutral points and charged points. The locations which are electrically charged are represented by an open circle 17 represents. The laser 15 is preferably a pulsed laser, for example a CO2 laser.

The exposure unit designed as a laser scanner 14 is able to print very quickly on the photoconductor line by line 11 to produce, whereby high production speeds can be achieved.

In an embodiment not shown, instead of the exposure unit designed as a laser scanner 14 an exposure unit with selectively controllable light sources, in particular laser diodes (LED), provided as an exposure unit. The LEDs are in the axial direction of the image drum 8th strung together, whereby according to the activation and activation of the respective light-emitting diodes individual points of the photoconductor 11 are neutralizable.

For equipping the image drum 8th with production material, the production head comprises one of the exposure unit 14 in working direction 10 the picture drum 8th subsequently arranged developer unit 18 , The developer unit 18 comprises at least one electrostatically chargeable transfer roller, in the present embodiment, four transfer rollers 19-1 . 19-2 . 19-3 . 19-4 , for the reception and supply of production material. The transfer rollers 19-1 . 19-2 . 19-3 . 19-4 , are parallel to the image drum 8th arranged and provide different manufacturing materials. The transfer rollers 19-1 . 19-2 . 19-3 . 19-4 are on a rotatably arranged transfer carousel 20 held such that in each case a transfer roller 19-1 in an active position adjacent to the image drum 8th is movable.

The transfer drums 19-1 . 19-2 . 19-3 . 19-4 are rotatably mounted and take from their respective associated material container on its circumference manufacturing material, which with the rotation of the transfer roller in opposition to the image drum 8th is brought.

The production material is held on the respective transfer roller via electrostatic charges. This is the transfer roller 19-1 . 19-2 . 19-3 . 19-4 associated with a corresponding charging unit. The charge of the production material on the production rolls is electrically opposite to the charge of the photoconductor 11 set. At the by the circles 17 In accordance with the exposed printed image charged points is locally selective production material from the active transfer roller 19-1 to the image drum 8th to hand over.

With the further movement of the image drum 8th in working direction 10 the production material becomes according to the filled circles 21 in the direction of material transfer 12 advanced. The production material is advantageously granulated or provided in powder form. In particular, for the arrangement of support material in the respective layer to be produced and liquid production materials are advantageous. For this purpose, appropriate support manufacturing materials are used, which according to the principle of electrophotography on the electrostatic charge of the photoconductor 11 can be transferred selectively.

Finally, the production head comprises a working direction of rotation 10 the picture drum 8th before the material transfer 12 arranged and in the direction of the production document 2 acting electrical underlay conditioning 22 , The document conditioning 22 is on the housing of the production head 3 held. The document conditioning 22 can be equipped in the manner of a corotron with corona wires, which are the manufacturing document 2 or ionize the material layers already deposited thereon. In another embodiment, the document conditioning includes 22 one in the axial direction of the image drum 8th that is in the transverse direction of the production document 2 , arranged array of point charging diodes. The paper conditioning is dimensioned such that the charges generated by the paper conditioning (circles 23 ) are larger than those of the conditioning unit 13 generated charges (circles 17 ). In this way it is ensured that the production material on the circumference of the image drum 8th in the opposition position, that means in the closest distance to the production document 2 , on the production document 2 or the material layers already arranged thereon is deposited or automatically skipped due to the electrical charge.

The production head 3 further comprises a fixing unit 24 for melting of production material. The fuser 24 is designed such that the of the image drum 8th on the production document or on the manufacturing base previously fabricated material layers deposited production material can be melted. The fuser 24 is therefore in working direction 10 downstream of the image drum and in the area of a floor of the housing 40 of the production head 3 arranged. The fuser 24 is therefore from the production head 3 movable in the manner of a carriage over the locally selectively deposited material.

The fuser 24 the main production head 3 includes a laser 25 namely, in the embodiment shown a pulsed CO2 laser, and one the laser 25 associated optical deflection device. In the exemplary embodiment shown, the deflecting device is a rotatably arranged mirror which transmits the laser beam 27 the laser 25 in the direction of the production document 2 deflects. The mirror 26 is preferably a hexagonal mirror. The mirror 26 is continuously kept in a continuous rotary motion and forms with the laser 25 a laser scanner, the laser beam 27 , or its laser pulses, transversely to the working direction 5 lying lines is deflected. By appropriate control, that is switching on and off of the laser 25 , the laser is turned on reaching such places, where previously from the image drum 8th site-selectively deposited production material is to melt. After liquefaction by the action of the fixing unit 24 solidifies the production material. The solidified area of the production material is represented by the filled rectangle 28 represents.

Each peripheral portion of the image drum 8th that is, parallel to the axis of rotation of the image drum 8th lying shell sections, reach after passing the material transfer 12 and passing through a return section 29 the picture drum 8th again the conditioning unit 13 where a new work cycle of the production head 3 starts. In the area of the return section 29 which between the material transfer 12 and the conditioning unit 13 is a material scraper 30 arranged. The material scraper 30 limited to the surface of the image drum 8th a narrow gap and optionally prevents the surface of the image drum 8th Remaining material residues on further transport. Rather, the remnants of the material are mechanically separated from the surface and in the material scraper 30 collected. In other embodiments, other cleaning units may be provided, such as brushes or the like. In the return section 29 is finally a discharge unit 31 arranged, which optionally on the photoconductor 11 remaining charges (circles 17 ) neutralized. In the embodiment shown, the discharge unit 31 structurally with the material wiper 30 or the cleaning units connected.

In 4 is a schematic cross section of a support manufacturing head 4 which is related to the arrangement of image drum 8th Conditioning unit 13 , Exposure unit 14 , Developer unit 18 and document conditioning 22 the main production head 3 according to 3 equivalent. Also a material scraper 30 and a discharge unit 31 are according to the material scraper of the main production head 3 ( 3 ) arranged. Instead of a revolver-like transfer carousel 20 with four transfer rollers 19-1 . 19-2 . 19-3 . 19-4 Also, other numbers of transfer rollers may be attached to their support manufacturing head 4 be provided. In particular, for series or mass production ("rapid manufacturing") is often a single support material, such as a water-soluble adhesive or similar binder material sufficient. In such embodiments of the support manufacturing head according to the invention 4 is in place of the transfer carousel 20 a single transfer roller is provided. The transfer roller is as already closed 3 described equipped with support material. The support material may be powdered, granular or liquid.

Unlike the main production head 3 includes the support manufacturing head 4 a fuser 32 which comprises a heat source. The heat source is matched to the intended support material to that of the image drum 8th solidify applied support material. The heat source preferably comprises one or more ultraviolet lights, which in a direction transverse to the working direction 5 of the support manufacturing head 4 lying working area on the deposited material layer act.

5 shows a particularly advantageous embodiment of a main production head 4 , which for two opposite directions of work 5 is trained. The manufacturing facility operates by a main manufacturing head according to 5 with a double production speed compared to a design with the production head according to 3 , The production head 4 includes in the embodiment according to 5 for a first working direction, a first equipment with conditioning unit 13 , Exposure unit 14-1 , Developer unit 18-1 , Document conditioning 22-1 and fixing unit 24-1 and a second equipment for a second working direction opposite to the first working direction. The second equipment also includes the conditioning unit 13 , an exposure unit 14-2 , a developer unit 18-2 , a document conditioning 22-2 and a fixing unit 24-2 , The second equipment is arranged substantially symmetrically to the first equipment and the respective units around the image drum 8th grouped. In the example shown is a common conditioning unit 13 provided, which is centrally located and constantly in operation and the photoconductor 11 the picture drum 8th conditioned. The conditioning unit 13 , the exposure units 14-1 . 14-2 , the developer units 18-1 . 18-2 , the document conditioning 22-1 . 22-2 and the fixation units 24-1 . 24-2 both equipment for the respective work directions 5 are identical and according to the description too 3 arranged and trained.

The main production head 3 Also includes for each equipment a cleaning unit, namely in the embodiment shown a Materialabstreifer 30-1 . 30-2 , It also includes the main manufacturing head 3 two end-loading units 31-1 . 31-2 , which analogous to the structure according to 3 in the area of material scrapers 30-1 . 30-2 are arranged.

The picture drum 8th of the main production head 3 according to 5 is in opposite working directions 10 operated. After the main production head in one direction 5 the end of the workspace 6 ( 1 . 2 ), becomes the main manufacturing head 3 moved in the opposite direction of rotation and at the same time the working direction 10 the image drum reversed. The two configurations with conditioning units, exposure units, developer units, underlay conditioning and fuser units can be activated as an alternative. With the switching of the working direction 5 the production head and the concomitant reversal of working direction 10 the picture drum 8th the up to then active equipment is switched off and the other equipment is activated.

6 shows a support manufacturing head 4 which is similar to the main production head 3 according to 5 for opposite directions of work 5 is trained. The support manufacturing head 4 according to 6 has a first equipment with conditioning unit 13 , Exposure unit 14-1 , Developer unit 18-1 , Document conditioning 22-1 and fixing unit 24-1 on. This first equipment is in a working direction 10 according to the description of the support manufacturing head according to 4 activated. The support manufacturing head 4 according to 6 includes a second equipment with an exposure unit 14-2 , Developer unit 18-2 , Document conditioning 22-2 and a fixing unit 24-2 which can be activated as an alternative to the first equipment. It will be after switching the working direction 10 the picture drum 8th activated. The control unit, not shown, of the production device controls accordingly after reaching one end of the work area 6 ( 1 . 2 ) and a switching of the working direction of the production heads the working direction 10 the picture drum 8th and activates the other equipment.

With the production device according to the invention, different production materials can be combined with rapid and accurate production. In addition, a coloring of individual production materials by color particles is possible. Compared with conventional generative manufacturing processes, the production facility according to the invention provides an increased construction area. In particular, high production speeds are achieved, since the production material is not heated in layers and - as for example in selective laser sintering or laser melting, a cooling of the just-processed material layer must be awaited. Another advantage of the manufacturing device according to the invention is the reduction of material waste in different materials, since binder-free materials are used with the production device according to the invention and no impurities arise.

The fixation unit of the main manufacturing head with a laser allows complete melting of the locally selectively presented portions of material, whereby in a simple manner, when using a plurality of production materials alloys are joined together. With correspondingly fine-grained or liquid production materials, very fine surface structures can be produced.

The formation of the manufacturing device with one or more main production heads and one or more support production heads 4 That is, the introduction of multiple components allows the use of different adhesives to realize different functions, for example, on highly loaded components.

Claims (15)

Generative production device for the layer-wise additive production of three-dimensional objects, with at least one production document ( 2 ) and at least one production head ( 3 . 4 . 4 ' ) for the site-selective arrangement of granulated, powdered or liquid production material on the production base ( 2 ) or on the production document ( 2 ) previously fabricated material layers, which at least one fixing unit ( 24 . 24-1 . 24-2 ) for melting production material, the production document ( 2 ) and the production head ( 3 ) according to one working direction ( 5 ) in the plane of a layer, as well as in a feed direction ( 7 ) are arranged relative to the thickness of the layers against each other displaceable, characterized in that the production head ( 3 . 4 . 4 ' ) is formed such that the production material via a according to predetermined manufacturing grids for the respective layer location-selectively exposed photoconductor ( 11 ) is receivable and transportable to the production site, wherein the production head ( 3 . 4 . 4 ' ) has the following characteristics: - an electrophotographic image drum ( 8th ), which on her coat a photoconductor ( 11 ) and in the area of a material handover ( 12 ) of Manufacturing head ( 3 ) compared to the production document ( 2 ), - at least one electrical conditioning unit ( 13 ) for electrostatic charging of the photoconductor ( 11 ) of the image drum ( 8th ), - at least one of the conditioning units ( 13 ) in working direction ( 10 ) of the image drum ( 8th ) subsequently arranged exposure unit ( 14 . 14-1 . 14-2 ), which means for the location-selective exposure of the photoconductor ( 11 ) of the image drum ( 8th ), - at least one of the exposure unit ( 14 . 14-1 . 14-2 ) in working direction ( 10 ) of the image drum ( 8th ) subsequently arranged developer unit ( 18 . 18-1 . 18-2 ) with at least one electrostatically chargeable transfer roller ( 19-1 . 19-2 . 19-3 . 19-4 ) for providing production material which is parallel to the image drum ( 8th ) is arranged, - at least one in working direction ( 10 ) of the image drum ( 8th ) before the material handover ( 12 ) and in the direction of the production document ( 2 ) electrical underlay conditioning ( 22 . 22-1 . 22-2 ). Manufacturing device according to claim 1, characterized in that the exposure unit ( 14 . 14-1 . 14-2 ) as means for the location-selective exposure of the photoconductor ( 11 ) of the image drum ( 8th ) a laser ( 15 ), in particular a pulsed laser, and a laser ( 15 ) associated optical deflection device, in particular a rotatably mounted deflection mirror ( 16 ). Manufacturing device according to claim 1, characterized in that the exposure unit ( 14 . 14-1 . 14-2 ) as means for the location-selective exposure of the photoconductor ( 11 ) of the image drum ( 8th ) in the axial direction of the image drum ( 8th ) juxtaposed, selectively controllable light sources, in particular light-emitting diodes, having. Manufacturing device according to one of the preceding claims, characterized in that the transfer roller ( 19-1 . 19-2 . 19-3 . 19-4 ) is assigned a loading unit. Manufacturing device according to one of the preceding claims, characterized in that in between a transfer of material ( 12 ) and conditioning unit ( 13 ) return section ( 29 ) of the image drum ( 8th ) a cleaning unit, in particular a material scraper ( 30 ) is arranged. Manufacturing device according to one of the preceding claims, characterized in that in between a transfer of material ( 12 ) and conditioning unit ( 13 ) return section ( 29 ) of the image drum ( 8th ) a discharge unit ( 31 . 31-1 . 31-2 ) is arranged. Manufacturing device according to one of the preceding claims, characterized in that the conditioning unit ( 13 ) and / or the document conditioning ( 22 . 22-1 . 22-2 ) corotron comprising corona wires or transversely to the working direction ( 5 ) of the production head ( 3 . 4 ) arranged point charging diodes. Manufacturing device according to one of the preceding claims, characterized in that the developer unit ( 18 . 18-1 . 18-2 ) several transfer rollers ( 19-1 . 19-2 . 19-3 . 19-4 ) for each different manufacturing materials, which on at least one rotatable transfer carousel ( 20 ) are held such that according to the principle of a revolver in each case a transfer roller ( 19-1 . 19-2 . 19-3 . 19-4 ) in an active position adjacent image drum ( 8th ) is movable. Production device according to one of the preceding claims, characterized in that the production head ( 3 ) for a first working direction ( 5 ) a first equipment with at least one conditioning unit ( 13 ), Exposure unit ( 14-1 ), Developer unit ( 18-1 ), Document conditioning ( 22-1 ) and fixing unit ( 24-1 ) and for a first working direction opposite second working means a second equipment with at least one conditioning unit ( 13 ), Exposure unit ( 14-2 ), Developer unit ( 18-2 ), Document conditioning ( 22-2 ) and fixing unit ( 24-2 ), which is arranged substantially symmetrically to the first equipment. Manufacturing device according to one of the preceding claims, characterized in that the fixing unit ( 24 . 24-1 . 24-2 ) of the production head a laser ( 25 ), and a laser ( 25 ), optical deflecting device, in particular a rotatably arranged deflecting mirror ( 26 ). Manufacturing device according to one of the preceding claims, characterized by at least one production head as main production head ( 3 ) for manufacturing material and one coordinated with the main manufacturing head ( 3 ) controllable production head as a support production head ( 4 ) for support material. Manufacturing device according to claim 11, characterized in that the support production head ( 4 ) with regard to the arrangement of image drum ( 8th ), Conditioning unit ( 13 ), Exposure unit ( 14 . 14-1 . 14-2 ), Developer unit ( 18 . 18-1 . 18-2 ) and document conditioning ( 22 . 22-1 . 22-2 ) the main production head ( 3 ) corresponds. Manufacturing device according to claim 11 or 12, characterized in that the at least a fuser unit ( 32 ) of the support manufacturing head ( 4 ) comprises a heat source. Production device according to one of the preceding claims, characterized in that the document conditioning ( 22 . 22-1 . 22-2 ) are configured in such a way that an amount of the 22 . 22-1 . 22-2 ) is greater than an amount that can be generated by the conditioning unit ( 13 ) producible charge of the image drum ( 8th ). Manufacturing device according to one of the preceding claims, characterized in that the conditioning unit ( 13 ) and / or the document conditioning ( 22 . 22-1 . 22-2 ) are either both designed to generate a negative electrostatic charge or to generate a positive electrostatic charge or formed switchable between a setting for generating a negative electrostatic charge and a setting for generating a positive electrostatic charge.

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