DE102021106759A1 - Device and method for carrying out an additive manufacturing method - Google Patents

Abstract

The invention relates to a device for carrying out an additive manufacturing method for manufacturing three-dimensional objects from a curable manufacturing material. The device for carrying out an additive manufacturing process has a housing, a print head mounted on the housing with at least one printing nozzle for applying the manufacturing material, and a holding device (1) arranged in the housing for printing the object. The print head and the holding device (1) can be displaced relative to one another. The holding device (1) for receiving the object to be printed is pivotably mounted so that an underside or an upper side of the holding device (1) faces the print head.

Description

The invention relates to a device for carrying out an additive manufacturing method for manufacturing three-dimensional objects from a curable manufacturing material, the device having a print head with at least one printing nozzle for applying the manufacturing material and a holding device for printing the object, the print head and the holding device being displaceable relative to one another are.

An additive manufacturing process is understood to mean all those manufacturing methods in which a three-dimensional object can be manufactured from one manufacturing material or from a number of possibly different manufacturing materials. Solid objects can be produced, with the term solid objects in the following also being understood to mean objects with a cavity or objects with recesses partially or completely penetrating the object. The production is computer-controlled from liquid, solid or pasty production materials. In this case, the production material is usually applied in layers by a print head, which is usually arranged in a housing, by means of a pressure nozzle onto a holding device which is also arranged in the housing, with the holding device serving as a construction platform. The applied layer is then sufficiently solidified via a physical and/or chemical curing process before a further layer is applied to the previously applied layer. In the case of large printing devices, the print head and the holding device can also only be mounted on a common stand or frame, without a surrounding housing being provided or necessary. Additive manufacturing processes are mostly used for the production of models, individualized display and functional models or prototypes, or for the production of small or very small quantities, since, for example, cost-intensive molds can be dispensed with for production. Other niche applications use these processes in military technology, medical technology, sportswear, shoes and in the home. It is considered an advantage that additive manufacturing can be used to produce individual or individually adapted three-dimensional objects without much effort. With the development of more and more efficient devices and manufacturing materials, the spread and use of such devices in all areas of object manufacture and production is increasing rapidly.

When using solid production materials such as metals or ceramics, which can only be brought into a state that can be applied conventionally with great and cost-intensive effort, processes such as laser beam melting, electron beam melting and laser sintering are used. In this case, objects are gradually melted or sintered into the powder bed from a metal powder or ceramic powder bed previously applied in layers to the holding device by means of a laser or an electron beam arranged on a working head.

In the case of plastics, for example, a meltable and recurable material can be melted using a print head with one or more pressure nozzles attached to it in a so-called melt layering and then applied in layers to the holding device. In addition to curing by drying or by cooling, methods are known in which crosslinking and thus curing of the applied and reactive production material can take place by means of electromagnetic radiation. Such a method for crosslinking silicone elastomers, for example, is described in the publication WO 2016/071241 A1 disclosed.

All of the methods presented so far have in common that each additional layer or each additional quantity of production material is applied in such a way that the new production material is in contact with the previously applied production material. If two or more different manufacturing materials are used, a suitable connection of the individual layers or areas must be ensured.

The print head and the holding device are mounted in such a way that they can be moved relative to one another. Conventional and inexpensive devices for the additive manufacturing process have a print head that can be moved in the x-y direction of a Cartesian coordinate system, with the holding device being mounted so that it can be moved in the z direction relative thereto. After depositing a layer of the object of production material, the fixture is lowered or the printhead raised accordingly by the layer thickness of the deposited material before another layer is deposited. In addition, further variants are known in which the holding device and/or the print head are movably mounted in three spatial directions.

In the pamphlet U.S. 9,002,496 B2 a device is disclosed in which the holding device has an axis of rotation in the axial extension of the z-axis. Due to the all-round movable arrangement of the print head and the additional possible rotation of the holding device, there is less need to change the direction or the speed of the holding device or the to change the print head during the application of the individual layers of an object. By avoiding rapid movements and accelerations, particularly in the case of rotationally symmetrical objects, the use of powerful and therefore also cost-intensive motors for driving the holding device and the print head can be dispensed with without slowing down the production speed.

For the manufacture of complex objects with, for example, overhangs, most devices for an additive manufacturing process require support structures that support the overhangs during the manufacture of the object in order to prevent deformation. However, these support structures have to be removed in an often complex post-processing of the manufactured object, which can lead to optical defects on the overhangs.

It is therefore considered the object of the present invention to provide a device for an additive manufacturing method with which an object can be manufactured from a curable manufacturing material as quickly and with little effort as possible.

This object is achieved in that the holding device has two spaced-apart receiving areas, between which a support structure that can be printed from opposite sides can be arranged and connected to the holding device via the receiving areas in such a way that the supporting structure can be printed on from both sides of the supporting structure. The holding device can be implemented, for example, as a plate with a flat upper side, on or to which the supporting structure can be fastened. The receiving areas can be arranged along two opposite edge areas of a recess in the plate in such a way that the support structure is arranged in the recess between the two receiving areas and can be fixed to the receiving areas. Since the support structure within the recess is not covered by the holding device or shielded from the environment, areas of the object on the support structure can be printed with the print head from all sides or at least from opposite sides.

Any discharge device or application device with which a hardenable production material for the additive production of a three-dimensional object can be discharged or applied to a support structure or to an already produced object area is referred to as a print head. Any material that can be applied with a suitably designed print head and applied in a sufficiently controlled manner to a substrate or to a three-dimensional object that has already been started can be used as the curable production material in order to cure there. The material of manufacture is preferably initially flowable. The curing process can either take place without external support or can be accelerated, for example, by heating, cooling, exposure to UV light, or by another suitable manner. The initially usually pasty production material can emerge from a print nozzle of the print head almost without pressure or subjected to a discharge pressure. It is also possible for the manufacturing material to be fed to the print head in powder form and only liquefied shortly before exiting the print head. Alternatively, it can also be provided that the manufacturing material is applied in powder form and solidified, for example, by laser sintering.

The continuous recess can preferably be arranged in the center of the plate and surrounded on all sides by receiving areas of the holding device. The continuous recess can also be designed as a laterally open recess in a C-shaped holding device, for example.

In addition, the holding device can have two mutually arranged and connected to one another or separate holding device sub-elements, which are realized, for example, as flat plates or as approximately punctiform receptacles. The supporting structure can be arranged between the holding device sub-elements arranged at a distance from one another and can be fixed or supported in a suitable manner on the holding device or on the holding device sub-elements. When designing the holding device from two separate holding device sub-elements, the distance between them can be varied by shifting the two elements relative to one another, so that the desired distance can be set and this can be adapted to the dimensions of the supporting structure. The two holding device sub-elements can be mounted independently of one another in a frame and held by suitable displacement devices and displaced relative to one another. The two holding device part elements can also be connected to one another via a suitable adjustment device, so that only one holding device part element has to be mounted on a frame of the device and the second holding device part element can be fixed to the first holding device part element via the adjustment device and can be displaced relative thereto.

By suitably adapting and specifying the dimensions of the support structure to the object to be printed, the printing time and the material costs can be reduced, since a support structure that unnecessarily exceeds the dimensions of the object to be printed can be dispensed with. In the case of a support structure that is produced separately, the material required can be reduced by adapting it to the object to be printed, analogously to a support structure printed by the device, and production costs can therefore be saved.

With the device designed according to the invention, objects with large dimensions, for example with dimensions greater than 300 mm, can also be produced in a simple and reliable manner. By applying production material to the support structure and in particular to both sides of a support structure, problems can be avoided which can occur in the conventional manufacture of such objects and arise, for example, from excessive adhesion to a substrate or insufficient adhesion to a substrate. Since it is not necessary for the object to adhere to a substrate during the production process, homogeneous object structures can be produced without tension and with particular precision.

The holding device itself can be made of a dimensionally stable material, preferably metal or a composite material.

According to an advantageous embodiment of the inventive concept, it can be provided that the device has two or more print heads, which can apply production material for the object to be printed from opposite sides of the holding device to a support structure that can be printed on both sides. By arranging two or more print heads on opposite sides of the holding device, both sides of the support structure can be printed simultaneously or alternately, with each print head only having to be shifted over a small adjustment path during the printing process. By printing the support structure and not the holding device, the support structure can be removed from the holding device together with the object without much effort after the object has been completed.

According to an advantageous embodiment of the idea of the invention, it is provided that the holding device is pivotably mounted. By pivoting the holding device, for example, a lateral area that does not originally face the print head can be aligned in the direction of the print head and is thus more easily or quickly accessible for the print head in order to be able to print a further area of the object to be produced there. It is also possible to align undercuts or protruding formations in the direction of the print head or upwards by changing the orientation of the object during the printing process, so that the curable manufacturing material can be applied by the print head in the corresponding areas of the object without additional support structures being printed or must be applied until the curable material has cured. If the holding device is pivoted far enough until its underside faces the print head, otherwise inaccessible areas of the object to be produced can also be made accessible during the production process. In addition, the shortest possible displacement path of the print head and the holding device can be implemented relative to one another, and rapid production of the object to be printed can be made possible even in the case of simple objects that are free of undercuts.

According to a particularly advantageous embodiment of the idea of the invention, it is provided that the pivotable mounting of the holding device is designed in such a way that an underside or an upper side of the holding device can optionally face the print head. By pivoting the holding device multiple times by 180° in each case, a top side of the object and a bottom side of the object can be successively applied to opposite sides of the support structure in successive production steps by a single print head. A new layer or an additional area of the manufacturing material can be applied to the side facing the printhead. On the opposite side, the previously applied material can harden before the holding device is turned and the opposite side is again turned towards the print head for another application process.

On the side opposite the print head, curing of the previously applied material can be assisted by a suitable curing device. For example, a heating device can heat a region of the support device opposite the print head with the manufacturing material already applied there and thereby accelerate the curing process.

The support structure can be, for example, a thin plate, a thin grid or a mesh or thread structure. The object to be manufactured can be pressed onto the supporting structure from both sides with the help of the swiveling holding device. Through the openings in the support con The material applied from both sides can connect to each other in the structure, so that a materially bonded connection area of the object encloses the supporting structure. The area of the support structure enclosed in this way remains in the object. Areas of the support structure that protrude laterally beyond the object can be subsequently separated and removed.

The supporting structure is preferably made from the same manufacturing material as the object to be manufactured, so that no foreign body or other material has to be embedded in the object after its manufacture. However, it is also possible that different manufacturing materials are used for the object to be printed and the supporting structure. For example, the material of manufacture of the support structure can be made of a water-soluble material, so that if a water-insoluble material of manufacture is used for the object to be printed, the support structure can be removed after the object has been completed.

The supporting structure can be produced, for example, before the start of the production of the object and fixed to the holding device. The receiving area of the holding device can have protruding pins or hooks or other formations to which the support structure can be fixed. The receiving area can also have a clamping device in which the support structure can be clamped and fixed.

Particularly preferably, it is optionally provided that the support structure itself can be produced with the device according to the invention. When printing a net-like support structure of, for example, interconnected struts made of a thermoplastic and/or duroplastic material, these can contract during hardening due to the tensile forces occurring in the longitudinal direction within the printed threads. The associated volume contraction allows the printed support structure to be additionally fixed to the receptacles of the receiving area, in that sections of the contracting support structure engage behind protruding shapes or hooks or in openings in the receiving area and are thereby braced. In addition, by contracting the support structure, the object printed on the support structure can be additionally fixed to the support structure if the printed object engages in recesses in the support structure and these recesses contract together with the support structure, resulting in a clamping effect on the object that engages in the recesses object is created.

By using the same material for the support structure and for the object, it can be prevented that a detachment of a first layer from the holding device made of a different material can lead to an unwanted termination of the process. In addition, manufacturing materials can also be used which have only little or no adhesion to the holding device, but adhesion to the supporting structure. When using the same material for the supporting structure and for the object to be produced, an advantageous material connection can also be produced between the supporting structure and the object printed onto the supporting structure, so that the object is reliably fixed to the supporting structure during the manufacturing process.

The two spaced-apart receiving areas of the holding device can be formed, for example, by rod-shaped or bar-shaped extensions that protrude from a holding device base element. The support structure can, for example, have eyelets, loops, pockets or other recesses into which the rod-shaped or bar-shaped extensions can engage, so that the support structure can be fixed to the holding device via the rod-shaped or bar-shaped extensions. In addition, latching tongues for fastening the support structure are also conceivable. The receiving area preferably has a plurality of receptacles arranged at a distance from one another, in which case the forces acting on the supporting structure can be reduced. Furthermore, the holder can be designed as a holder frame, wherein the holder frame is designed or can be arranged on the holder area, and the support structure can be fastened to the holder area by, for example, clamping or hooking the holder frame. Advantageously, the receptacle is formed from parallelepiped-shaped extensions which are arranged at a distance from one another on the receptacle area and protrude in the transverse direction to the retaining plate and which can serve as anchor points for an applied support structure.

For fixing to the projecting receptacle, the support structure can have loops, for example, which lie around pin-shaped formations in the receptacle areas and are thus fixed to them, with the loops being arranged along the outer edge of the support net. The support structure can also be printed on three-dimensionally structured surface areas in the receiving areas, so that the receiving areas overlap Edge areas of the support structure are fixed to the receiving areas during curing.

According to an advantageous implementation of the idea of the invention, it is provided that the device has a closure plate with which the recess in the holding device can be closed. The support structure that can be applied by the device according to the invention can be applied to the surface created by the closure of the recess by the closure plate. The support structure is advantageously designed as a support net or support grid, which is printed on the closure plate with the print head in a previous work step and is self-supportingly fixed to the receptacle after curing and removal of the closure plate. For this purpose, the support net or support grid can extend beyond the closure plate into the adjoining receiving area of the holding device and can be fixed there to protruding formations. Any gaps between the closure plate arranged in the recess and the surrounding frame-shaped holding device, which result from the recess being incompletely closed by the closure plate, can be overprinted when using a pasty manufacturing material.

Advantageously, it is optionally provided according to the invention that the recess of the holding device can be closed flush with the receiving area of the holding device by moving the closure plate in a direction transverse to the holding device. The closure plate can preferably be mounted and aligned parallel to the holding device, as a result of which the recess of the holding device can be closed by linear displacement of the closure plate perpendicular to the surface of the holding device. The closure plate can be moved in such a way that the upper side of the closure plate results in a surface flush with the receiving area of the holding device that is suitable for the application of the supporting structure.

Optionally, the closure plate can also have a heating device integrated into or fixed to the closure plate. In this way, the closure plate can first close the receiving area of the holding device and be used to produce the supporting device, in order to then use the heating device to accelerate the curing of the supporting device and then the curing of the production material applied to the supporting device. The closure plate can also be arranged at a suitable distance from the supporting device or the object already produced on it during a heating and curing process.

In the case of comparatively heavy objects, in particular, the closure plate can also be used to support the object under construction during the manufacturing process. For this purpose, the closure plate can be moved from below to the support structure or to a region of the object that projects downwards and brought into contact in order to be able to absorb a weight force and be able to dissipate it via the closure plate. Separate support elements can also be provided which, if necessary, can be brought up to and brought into contact with the support structure or the object being produced from below during the production process.

According to an advantageous embodiment of the idea of the invention, it is provided that the holding device can be rotated by any desired pivoting angle about a pivot axis arranged parallel to a longitudinal axis of the holding device. The pivot axis is advantageously arranged along the longitudinal axis in the middle of the holding device, so that when the holding device is pivoted, one side of the support structure faces the print head and can be printed on. In this way, the holding device can always be pivoted further in the same direction of rotation in order to alternately face the upper side and the underside of the holding device to the print head arranged above it. An alternately directed pivoting movement is not necessary, but can be expedient in individual cases. In addition to the alternating printing of the upper side and, and after pivoting the holding device, the lower side, simultaneous printing of the upper side and the lower side by means of print heads arranged on both sides of the holding device is also possible.

One possible design option of the holding device includes a variant in which the holding device has two holding device sub-elements arranged at a distance from one another and parallel, each holding device sub-element having a receiving area on a respective upper side for fixing a support structure extending between the two holding device sub-elements. The respective receiving area of the holding device part elements is designed in such a way that it is suitable for fixing the supporting structure. The support structure can, for example, have several support struts or support structure threads extending from one part of the holding device to the other. With the help of a movable print head or a movably mounted holding device these supporting struts or supporting construction threads stretched between the holding device sub-elements are additionally wrapped with the production material or with a separate reinforcement material in order to enable additional reinforcement of the object. The reinforcement material can be made of a fiber material such as glass or carbon fibers. The isotropy can also be improved by wrapping. In this way, objects with a rotationally asymmetrical shape can be realized in addition to cylindrical, rotationally symmetrical objects such as tubes. Furthermore, the objects to be printed can have partial or continuous recesses and overhangs, with the topology of the object being able to be optimized by the reinforcement. Such a method can be used, for example, to print load-adapted supporting arm or leg splints, which can be adapted to the respective circumstances of the patient using the method according to the invention.

The two holding device part elements are expediently mounted such that they can pivot about a common pivot axis. It is also possible and optionally provided according to the invention that the holding device is rotatably mounted in all three spatial directions. This type of storage can make it possible to increase the speed of application of the individual interconnected layers or material regions by reducing the movement of the print head and the movement of the holding device relative to one another. Furthermore, with such a configuration of the mounting of the holding device, the representation of complex geometries with, for example, overhangs or undercuts of the object is possible without the use of support structures.

It is furthermore optionally provided according to the invention that the holding device has an upper side directed towards the print head and an underside opposite the upper side. When using pasty or liquid production materials, the holding device is preferably arranged parallel to the substrate, or at an angle that deviates only slightly from the horizontal, so that gravity-related lateral or downward running of the production material before curing is possible can be avoided. In addition, stresses within the applied production material, deformations and unclean contours can be avoided in this way, such as can result from uncontrolled flow of the production material during curing.

According to an advantageous implementation of the idea of the invention, it is provided that the print head is arranged at a distance from the upper side of the holding device and the print head is mounted so that it can rotate in all three spatial directions. Such an all-round rotatable mounting of the print head not only makes it possible for complex structures to be printed, but in particular with a all-round rotatable mounting of the holding device, the printing speed can be increased due to the shortest possible paths of the print head and the holding device.

Advantageously, it is optionally provided according to the invention that a curing device is arranged on a side of the holding device opposite the print head. With the curing device, the curable production material newly applied by the print head can be cured or its curing can be accelerated. As a result, the total manufacturing time required can be significantly reduced. The curing device can, for example, generate heat radiation which is directed and radiated from the side opposite the print head onto the support structure with the production material applied there. By using a curing device, objects can also be manufactured in an open work environment that can otherwise only be manufactured in closed and temperature-controlled construction spaces.

Depending on the respective manufacturing material, the curing device can be implemented as a heating device, for example as a heating wire, with which the printed object or the individual printed layers or areas can be heated and thus cured in a targeted manner. Furthermore, the curing device according to the invention can have radiation sources, in particular electromagnetic radiation types such as UV radiation, infrared radiation and X-ray radiation. For example, UV radiation or X-rays can be used to polymerize suitable monomers via free-radical polymerization and thus cure them.

It is also conceivable that the curing device has heated contact areas, which are applied or pressed to the support structure or to the object areas applied thereto in order to heat and harden the production material particularly efficiently via direct contact between the heated contact areas of the curing device and the production material . Appropriate control of the curing device and in particular of the heated contact areas can also result in individual object areas being melted in a targeted manner and after a subsequent hardening are thus more strongly connected and solidified.

In order to ensure the simplest and most compact design possible for the device according to the invention, the curing device is preferably arranged in a stationary manner in the vicinity of or below the holding device. The curing device can also be arranged in a displaceable manner on a frame, stand or housing of the device and, if necessary, be moved closer to the object in order to bring about or accelerate the curing from as small a distance as possible. The energy input or the curing speed can be regulated via the distance between the object and the curing device and thus the energy input applied to the object in addition to the initial intensity applied. In particular when several devices for additive manufacturing are used simultaneously, it can be provided that a single curing device is arranged in such a way that the curing device can be used jointly by several devices for additive manufacturing. As an alternative to this or in addition to this, provision can be made for a curing device to be arranged on the working head or print head.

According to an advantageous embodiment of the idea of the invention, it is provided that the curing device can act on the object from a side opposite the at least one print head. Heat in the form of hot air, for example, can be directed via a heat blower from the curing device, preferably directed onto the printed object and in particular specifically onto individual layers or areas to be cured. In the same way, electromagnetic radiation can be emitted via a light source or can be brought to the object via a light guide. Radiation acting on the object to be cured in such a focused manner can reduce the power of the acting radiation and ultimately the costs, since, for example, a heated build chamber that surrounds the object to be printed and the at least one print head can be dispensed with. Furthermore, this targeted irradiation can ensure that newly applied layers of the object to be printed, which exceed a predetermined height and thus distance from the holding device, are evenly heated by pivoting the holding device and turning it towards the curing device, in order to prevent stress cracks caused by a temperature gradient in the object .

The pivotable mounting of the holding device makes it possible for the support structure to be pivoted after the application of a layer on the first side and for the layer previously applied to the first side to be cured with the aid of the curing device acting on the object from the opposite side while another layer is applied to the second side, opposite the first side and now facing the print head. The production speed can be increased by simultaneously curing on one side and applying another layer or layers on the other side.

The invention further relates to a method for producing three-dimensional objects from a curable production material, wherein a curable production material is applied to a holding device with a pressure nozzle and the object is thereby produced.

Methods for the additive production of three-dimensional objects are known from the prior art, in which, in the case of a complex shape of the object, the production time increases and complex support structures are also required. Depending on the respective curing time, the application of further layers or areas may have to be interrupted in order to wait for sufficient curing or crosslinking of the previously applied layers. This reduces the speed of building the object to be printed and increases the manufacturing time.

It is considered an object of the present invention to provide a method with which objects can be manufactured as quickly and efficiently as possible using an additive manufacturing method.

The object is achieved in that a first part of the object is produced in a first printing step, that in a first pivoting step the holding device is pivoted with the first part of the object produced on the holding device, and in a second printing step a second part of the object is produced.

The method can preferably be carried out using the device described above for carrying out an additive manufacturing method for manufacturing three-dimensional objects from a curable manufacturing material. Due to the possibility of pivoting the holding device during the application of further layers, complex geometric figures with overhangs can also be produced with liquid or pasty materials. Furthermore, it makes it possible, after the application of one or more layers, by pivoting the holding device further layers can be applied on the opposite side, while the layers applied first can be cured using a curing device. In particular in the case of larger or complex-shaped objects, it is possible to alternately carry out numerous further subsequent pivoting steps and pressure steps for the production of the object. Provision can also be made for the first pivoting step to be carried out at the same time or with a time overlap while the first or second printing step is being carried out.

The object can be printed directly on a surface of the holder. It is also possible for a support structure to be arranged over a continuous recess of the holding device before the first printing step. The support structure can be a fleece or a plate, for example. It is also possible for the support structure to be a support net or a support grid made from dimensionally stable rods or from flexible threads or bands. Since the object is held by the support structure in the area of the recess and is accessible from both sides of the holding device, the object can be printed from all sides with the print head by suitable pivoting of the holding device and can thus be produced particularly quickly and easily.

It is also possible and optionally provided according to the invention that in a support structure production step carried out before the first printing step, the recess of the holding device is closed with a closure plate, with a support structure being applied to the surface formed in this way from a closure plate top side and a holding device top side. The support structure is preferably printed onto the resulting surface by the print head and serves to hold the object to be printed. For example, the support structure can be in the form of a support mesh and has the same material as the object to be printed in order to be able to avoid any layer adhesion problems when using different production materials. Any layer adhesion problems that may occur can be improved by counter-pressure when applying the individual layers of the object to be printed to the support structure, or when printing the support structure on the receiving area.

It is also optionally provided according to the invention that the first part of the object is applied in the first printing step from the production material by a print head to a first side facing the print head of the recording produced in the supporting structure generation step, with the supporting structure serving as a support for the first part of the object . The closure plate can be brought up to the support structure from below and serve as a barrier when liquid or pasty production materials are applied to the support structure if the support structure used in each case contains recesses.

According to an advantageous implementation of the idea of the invention, it is provided that in the first pivoting step the closure plate is removed from the holding device and the holding device with the receptacle fixed to the holding device is rotated through 180° about a pivoting axis arranged parallel to a longitudinal axis of the holding device, so that a second side the support structure opposite the first side faces the print head. For mechanical support and thus a reduction in the forces acting on the support structure, particularly when printing large and/or heavy objects or with a large support structure, the closure plate can be shifted to the first part of the object printed in the first document. When the holding device is pivoted by 180° after one or more layers have been applied, the closure plate can be displaced by the thickness of the one or more layers applied, so that the closure plate rests against the object on the side facing away from the print head with each rotation. Furthermore, the closure plate can have the curing device in order to thermally support the curing.

Advantageously, it is optionally provided according to the invention that the second part of the object is printed in the second printing step from the production material via the print head onto the second side of the recording. The second applied part of the object is placed on the support structure such that the first part of the object, the second part of the object and the part of the support structure to which the manufacturing material has been applied form the finished object. Any protruding parts of the support structure are then removed.

Application of the manufacturing material to the support structure can be accomplished by a single print head. It is also possible that the production material is applied by two or more print heads. The two or more printheads can be arranged on one side of the holder. It is also possible and advantageous when using two or more print heads that the two or more print heads are arranged on opposite sides of the holding device and either simultaneously or alternately from both sides of the holding device direction from the manufacturing material can be applied to the support structure.

According to an embodiment of the idea of the invention that is considered to be particularly advantageous, it is optionally provided that the method according to the invention is carried out with the device described above and also configured according to the invention. All the advantages listed for the device according to the invention can also be realized with a correspondingly designed method. With the method according to the invention, the device can be operated particularly efficiently.

• 1 eine schematische Darstellung einer Draufsicht einer Haltevorrichtung einer erfindungsgemäßen Vorrichtung,
• 2 eine Schnittansicht der erfindungsgemäßen Vorrichtung mit einem Druckkopf und mit der in 1 gezeigten Haltevorrichtung entlang der Schnittlinie I-I in 1, wobei eine durchgehende Ausnehmung in der Haltevorrichtung nicht durch eine Verschlussplatte verschlossen ist,
• 3 eine Ansicht der Vorrichtung gemäß 2, wobei die durchgehende Ausnehmung in der Haltevorrichtung durch eine Verschlussplatte verschlossen ist,
• 4 eine Ansicht der Vorrichtung der gemäß in 3 gezeigten Haltevorrichtung mit einem darauf gedruckten Stütznetz,
• 5 eine schematische Darstellung einer Draufsicht auf die in 4 gezeigte Vorrichtung,
• 6 eine Ansicht der Vorrichtung mit der Haltevorrichtung, der Verschlussplatte, dem Stütznetz sowie mit einem ersten Teil eines auf dem Stütznetz aufgedruckten Objekts,
• 7 eine Ansicht der Vorrichtung gemäß 6 zu einem späteren Zeitpunkt des Herstellungsverfahrens, wobei nach der Herstellung eines ersten Teils des Objekts die Verschlussplatte aus der Haltevorrichtung herausgenommen ist,
• 8 eine Ansicht der Vorrichtung gemäß 7 zu einem späteren Zeitpunkt, bei welchem die Haltevorrichtung erfindungsgemäß um 180° verschwenkt ist und eine Unterseite der Haltevorrichtung dem Druckkopf zugewandt ist, wobei der erste Teil des gedruckten Objekts durch die Verschlussplatte gestützt ist.
• 9 eine Ansicht der Vorrichtung mit einem fertig hergestellten Objekt,
• 10 eine Schnittansicht der erfindungsgemäßen Vorrichtung mit der in 1 gezeigten Haltevorrichtung entlang der Schnittlinie I-I in 1, wobei die Oberseite und die Unterseite mit jeweils einem Druckkopf gleichzeitig bedruckt ist,
• 11 eine schematische Darstellung einer Draufsicht auf eine erfindungsgemäße Haltevorrichtung bestehend aus zwei Haltevorrichtungsteilelementen mit einer aufgedruckten Stützkonstruktion, wobei die Aufnahme teilweise von der Stützkonstruktion überdruckt ist,
• 12 eine Schnittansicht der erfindungsgemäßen Haltevorrichtung entlang der Schnittlinie XI-XI in 11,
• 13 eine vergrößerte Schnittansicht des Aufnahmebereichs aus 12,
• 14 eine Schnittansicht der erfindungsgemäßen Vorrichtung mit einem Druckkopf und der Haltevorrichtung, wobei die zwei Längsstreben der Stützkonstruktion als Armierung für eine aufgedruckte Röhre dienen,
• 15 eine Schnittansicht entlang der Schnittlinie XIV-XIV in 14 ohne die aufgedruckte Röhre
• 16 eine Schnittansicht gemäß 15 mit der aufgedruckten Röhre, und
• 17 eine Schnittansicht gemäß 16 mit herausgelöster Stützkonstruktion sowie Stützkörper.

Various advantageous configurations of the device according to the invention are explained on the basis of exemplary embodiments illustrated in the drawing. It shows:

• 1 a schematic representation of a top view of a holding device of a device according to the invention,
• 2 a sectional view of the device according to the invention with a print head and with the 1 shown holding device along section line II in 1 , wherein a continuous recess in the holding device is not closed by a closure plate,
• 3 a view of the device according to FIG 2 , wherein the continuous recess in the holding device is closed by a closure plate,
• 4 a view of the device according to in 3 holding device shown with a support net printed on it,
• 5 a schematic representation of a plan view of the in 4 shown device,
• 6 a view of the device with the holding device, the closure plate, the support net and a first part of an object printed on the support net,
• 7 a view of the device according to FIG 6 at a later point in time in the manufacturing process, with the closure plate being removed from the holding device after the manufacture of a first part of the object,
• 8th a view of the device according to FIG 7 at a later time, according to the invention, the holder is rotated 180° and an underside of the holder faces the print head, with the first part of the printed object being supported by the shutter plate.
• 9 a view of the device with a finished object,
• 10 a sectional view of the device according to the invention with the in 1 shown holding device along section line II in 1 , whereby the upper side and the lower side are each printed with one print head at the same time,
• 11 a schematic representation of a plan view of a holding device according to the invention consisting of two holding device part elements with a printed supporting structure, the recording being partially overprinted by the supporting structure,
• 12 a sectional view of the holding device according to the invention along the section line XI-XI in 11 ,
• 13 shows an enlarged sectional view of the receiving area 12 ,
• 14 a sectional view of the device according to the invention with a print head and the holding device, the two longitudinal struts of the supporting structure serving as reinforcement for a printed tube,
• 15 a sectional view along line XIV-XIV in 14 without the printed tube
• 16 a sectional view according to FIG 15 with the printed tube, and
• 17 a sectional view according to FIG 16 with detached supporting structure and supporting body.

1 shows a plan view of a holding device 1 of the device according to the invention. The holding device 1 is designed in the shape of a frame from a flat plate with an almost rectangular shape and with a continuous recess 2 from an upper side to an opposite underside. The recess 2 is rectangular like the holding device 1, the shape and the dimensions of the recess 2 and their arrangement within the holding device 1 can be specified in almost any way. The recess 2 is almost completely closed by a rectangular closure plate 3 . The upper side of the closure plate 3 is flush with the surrounding areas of the holding device 1 and forms an almost continuous surface with the upper side of the holding device 1 . On an inner edge of the upper side of the holding device 1, a circumferential receiving area 4 is formed, which has a recess 2 surrounding a row of spaced-apart recordings 5 in the entire receiving area 4, which as square fasteners tion elements are formed, which protrude from the top of the holding device 1.

In the 2 until 9 a chronological sequence of a manufacturing method carried out according to the invention of an object manufactured with the device according to the invention is shown using the example of a sphere.

In 2 1 is a sectional view of the holding device 1 along a longitudinal direction. 3 shows a sectional view along the section line II in 1 , wherein the recess 2 of the holding device 1 is almost completely closed by the closure plate 3. The top of the holding device 1 and a top of the closure plate 3 form an almost flat surface and face a print head 6 with a print nozzle 7 .

In 4 it is shown that a support network was printed with the print head 6 on the surface formed in this way. The support network forms the support structure 8 for the object to be subsequently manufactured. In the exemplary embodiment shown as an example, the object to be produced is a sphere. However, the object to be produced can be almost any object or shape, and in particular also objects with very complex shapes.

In 5 the surface formed by the closure plate 2 and the holding device 1 is shown with a support structure 8 designed as a support net. The support mesh can be made from a manufacturing material with a print head 6 of the device or with the print nozzle 7 fixed to the print head 6 . The support network has longitudinal and transverse struts arranged in parallel and connected to one another. The recording 5 with the projecting square fasteners serves as an anchoring and fixing area for the support network. The fasteners are overprinted with individual loops of the material of manufacture, the loops being located along the outer edge of the support mesh.

In 6 a point in time within the production process is shown at which a first part 9 of the ball to be printed has already been produced in a first printing step.

Before, during or after this, the closure plate 3 is removed from the recess 2 of the holding device 1, as shown in 7 is shown.

8th shows a later state in which the holding device 1 with the support net attached thereto and the first part 9 of the ball is rotated in a first pivoting step by 180° about a horizontal pivot axis, so that the underside of the holding device 1 faces the print head 6 and prints can be. The first part 9 of the sphere is hereby supported by the closure plate 3 which has been shifted towards the first part 9 of the sphere.

Subsequently, in a subsequent second printing step, a second part 10 of the sphere is printed onto the support mesh in such a way that a fully formed sphere 11 is produced as a result, as shown in FIG 9 is shown. When using pasty or solid manufacturing materials, the first 9 and the second part 10 of the ball 11 can be printed simultaneously or sequentially on the top and bottom. In 10 1 shows a holding device 1 with a ball 11 formed thereon, the two parts 9, 10 of the ball 11 being pressed onto the support structure 8 at the same time. Finally, the support net can be detached from the surrounding holding device 1 and the remains of the support net protruding beyond the surface of the sphere can be removed from the sphere 11 . If the same hardenable manufacturing material is used to manufacture the support network as was used to manufacture the ball 11, a homogeneous ball made from one material can be produced in this way.

11 shows a schematic representation of a top view of a holding device 1 according to the invention. In this exemplary embodiment, the holding device 1 consists of two holding device part elements 12 which are spaced apart and aligned parallel to one another. The two holding device part elements 12 are arranged on a shaft 13, the two holding device part elements 12 being actuated by the shaft 13 can be pivoted. On the receiving area 4 of the holding device part elements 12, spaced-apart receptacles 5 are fixed in the edge area. A number of mutually associated receptacles 5 of a holding device part element 12 are connected to one another via longitudinal struts printed from the manufacturing material, the longitudinal struts being printed over the receptacles 5 and completely enveloping them. In 12 a longitudinal sectional view of the holding device is shown along the section line XI-XI, while 13 shows an enlargement of the recording area 4 with an overprinted recording 5.

In 14 a sectional drawing of the holding device 1 is shown, with the print head 6 and one on the supporting structure 8 being shown as an example printed tube 14 are shown, while in Figs 15 until 17 a time sequence of the manufacturing process of the tube 14 is shown.

The support structure 8 in 14 in this case has two transverse struts which are arranged parallel to one another and connect the two holding device part elements 12 . The transverse struts are then overprinted in such a way that a cylindrical supporting body 15 enclosing the transverse struts is produced. The lateral surface of the support body 15 is provided with a reinforcement 16 made of glass fibers, which in this case serves as reinforcement for the tube to be printed on the reinforcement. The support body 15 is then wrapped in the transverse direction by the manufacturing material discharged from the printing nozzle 7 of the printing head 6 and thus forms a tube 14 which is additionally reinforced by the reinforcement. The supporting body 15 and the cross braces can then be removed using a suitable solvent, so that the finished tube 14 is obtained.

Reference List

1

holding device

2

recess

3

locking plate

4

recording area

5

Recordings

6

support structure designed as a support net

7

printhead

8th

pressure nozzle

9

First part of the object

10

Second part of the object

11

object formed as a sphere

12

fixture part element

13

Wave

14

tube

15

supporting body

16

reinforcement

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• WO 2016/071241 A1 [0004]
• US9002496B2 [0007]

Claims (19)

Device for carrying out an additive manufacturing method for manufacturing three-dimensional objects (9, 10, 11) from a curable manufacturing material, the device having a print head (6) with at least one pressure nozzle (7) for applying the manufacturing material and a holding device (1) for receiving the object (9, 10, 11) to be printed, the print head (6) and the holding device (1) being displaceable relative to one another, characterized in that the holding device (1) has two spaced-apart receiving areas (4) between which a support structure (8) that can be printed on from opposite sides can be arranged and connected to the holding device (1) via the receiving areas (4) in such a way that the support structure (8) can be printed on from both sides of the support structure. device after claim 1 , characterized in that the device has two or more print heads (6) which can apply production material for the object (9, 10, 11) to be printed on opposite sides of the holding device (1) to a supporting structure (8) which can be printed on both sides. device after claim 1 or claim 2 , characterized in that the holding device (1) is pivotably mounted. Device according to one of the preceding claims, characterized in that the pivotable mounting of the holding device is designed in such a way that an underside or an upper side of the holding device (1) can optionally face the print head (6). Device according to one of the preceding claims, characterized in that the device has a closure plate (3) with which the recess (2) in the holding device (1) can be closed. device after claim 5 , characterized in that the recess (2) of the holding device (1) can be closed flush with the receiving area (4) of the holding device (1) by moving the closure plate (3) in a direction transverse to the holding device (1). Device according to one of the preceding claims, characterized in that the holding device (1) can be rotated through any desired pivoting angle about a pivot axis arranged parallel to a longitudinal axis of the holding device (1). Device according to one of the preceding claims, characterized in that the holding device (1) is pivotably mounted in all three spatial directions. Device according to one of the preceding claims, characterized in that the holding device (1) has an upper side directed towards the print head (6) and an underside opposite the upper side. Device according to one of the preceding claims, characterized in that the print head (6) is arranged at a distance from the upper side of the holding device (1) and the print head (6) is rotatably mounted in all three spatial directions. Device according to one of the preceding claims, characterized in that a curing device is arranged on a side of the holding device (1) opposite the print head (6). device after claim 11 , characterized in that the curing device is arranged in such a way that the curing device can act on the object (9, 10, 11) from a side opposite the print head (6). Method for producing three-dimensional objects from a curable production material, a curable production material being applied to a holding device (1) with a pressure nozzle (7) and the object (9, 10, 11) thereby being produced, characterized in that in a first printing step a first part of the object (9, 10, 11) is produced in that in a first pivoting step the holding device (1) is connected to the first part (9) of the first part of the object (9, 10, 11) produced on the holding device (1) is pivoted, and wherein a second part (10) of the object (9, 10, 11) is produced in a second printing step. procedure after Claim 13 , characterized in that before the first printing step, a support structure (8) is arranged over a continuous recess (2) of the holding device (1). procedure after Claim 14 , characterized in that in a support structure production step carried out before the first printing step, the recess (2) of the holding device (1) is closed with a closure plate (3), a support structure (8) being applied to a surface formed thereby from a closure plate top side and a holding device top side becomes. Procedure according to one of Claims 14 or 15 , characterized in that the first part of the object (9) is applied in the first printing step from the production material with the print head (6) to a print head (6) facing first side of the support structure (8) produced in the support structure generation step, wherein the Supporting structure (8) serves as a support for the first part of the object (2). Procedure according to one of Claims 14 until 16 , characterized in that in the first pivoting step the closure plate (4) is removed from the holding device (1) and the holding device (1) with the supporting structure (8) fixed to the holding device (1) rotates about a axis parallel to a longitudinal axis of the holding device (1 ) extending pivot axis is rotated by 180 ° so that a second side of the support structure (8), which is opposite the first side, faces the print head (6). Procedure according to one of Claims 14 until 17 , characterized in that the second part of the object (2) is printed in the second printing step from the production material via the print head (6) onto the second side of the support structure (8). Procedure according to one of Claims 13 until 18 , characterized in that the method with a device according to one of Claims 1 until 11 is carried out.

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