Dosing device, additive manufacturing device and dosing method

Abstract

The invention relates to a dosing device (12) for being arranged on the outside of a process chamber (14) of an additive manufacturing device (10) and for conveying process powder into the process chamber (14), the dosing device comprising: - at least one powder container (44) having at least one powder cavity (46) which is designed to receive the process powder; - a container guide (48) for moving the powder container (44) in a straight line along a conveying axis (50) of the dosing device (12); wherein the powder container (44) is movably arranged on the container guide (48); and wherein the powder container (44) is designed to be deflected beyond the container guide (48) along the conveying axis (50). The invention further relates to an additive manufacturing device (10) and to a dosing method (88).

Description

[0001] Dosing device, additive manufacturing device and dosing method

[0002] Background of the invention

[0003] The invention relates to a dosing device for process powder. Furthermore, the invention relates to an additive manufacturing device and a dosing method.

[0004] Such dosing devices are typically used in additive manufacturing devices designed to produce workpieces from the process powder. The dosing device is used, among other things, to feed the process powder into a process chamber of the additive manufacturing device.

[0005] Typically, so-called coaters are used within the process chamber of the additive manufacturing device to distribute the process powder in a working cylinder. To enable fast and even distribution or "laying out" of the process powder, the dosing device is responsible for providing the process powder to the coater in pre-dosed amounts as precisely as possible.

[0006] A common device for conveying process powder into the process chamber involves a lifting device that transports the required process powder from below to the coater. However, this requires considerable space beneath the process chamber.

[0007] In addition to powder feed from below, other types of dosing devices are known from the prior art. EP 2 191 922 A1 describes a powder application device with two separate powder chambers. Each powder chamber has a conveyor shaft with several recesses that conveys a powder located in the powder chamber toward the powder outlet opening. The powder chambers are designed to be carried along with the coater.

[0008] DE 10 2020 129 420 A1 describes a coating device with several receptacles, wherein the receptacles are filled from above by means of a dosing device under the influence of gravity.

[0009] The dosing devices known from the prior art are arranged within the process chamber to provide the required process powder directly to the coater. However, this requires larger internal dimensions of the process chamber, which increases its volume. Since an additive manufacturing process is carried out under inert conditions, this increases the effort required to inertize the process chamber.

[0010] In addition, the dosing devices arranged in the process chamber represent a flow obstacle for the protective gas flow formed in the process chamber. This can lead to undesired flow vortices within the process chamber, which can cause process powder to be stirred up.

[0011] Object of the invention

[0012] It is an object of the invention to provide a dosing device in which a process chamber volume can be kept small and a low-turbulence protective gas flow can be ensured. It is also an object of the invention to provide an additive manufacturing device and a dosing method. Description of the invention

[0013] This object is achieved according to the invention by a dosing device having the features of claim 1. The object is also achieved by an additive manufacturing device having the features of claim 13. Furthermore, the object is achieved by a dosing method having the features of claim 17. The subclaims relate to preferred embodiments of the invention.

[0014] According to the invention, a dosing device is provided. The dosing device is designed for external arrangement on a process chamber of an additive manufacturing device. Furthermore, the dosing device is suitable, in particular designed, for conveying process powder into the process chamber of the additive manufacturing device.

[0015] A process powder is understood to be a working medium, in particular an additive manufacturing device, in powder form. In other words, the process powder is used to create a workpiece. A workpiece can be produced from various process powders, such as aluminum, silicon, magnesium, corundum, or titanium. This list is not intended to be exhaustive. The various process powders can differ, for example, in the particle size of the process powder, in a powder material, in particular a mixture of different powder materials, and / or in a powder color. For example, the use of an aluminum-silicon-magnesium alloy may be provided.

[0016] The dosing device has at least one powder container. Preferably, the dosing device has two or more powder containers. The powder container can have a powder container length that is formed predominantly along a conveying axis of the dosing device. The powder container length is preferably adapted to a powder coater width of the powder coater. The powder container length can be, for example, between 50 millimeters and 1200 millimeters. The at least one powder container has at least one powder cavity. The powder cavity is designed to receive and / or dispense the process powder. In other words, the powder container can store process powder.

[0017] The dosing device also has a container guide. The container guide is designed for linear movement of the powder container. Typically, the powder container is designed to be guided along the conveying axis of the dosing device.

[0018] In a particular embodiment, the dosing device can have a guide carriage. The at least one powder container can be arranged, in particular fastened, to the guide carriage. The guide carriage can be arranged so as to be translationally movable on the container guide.

[0019] The guide carriage preferably has a container holder. The container holder can be formed along the conveying axis. Typically, the container holder is designed to hold or support the powder container. Preferably, the container holder is designed to hold or support all powder containers of the dosing device. This can prevent the powder container from bending, particularly when the powder container has extended dimensions along the conveying axis.

[0020] The container guide preferably has a guide end that can be arranged on the process chamber. In other words, when the dosing device is arranged on the process chamber, the container guide extends to an outer side of the process chamber. This allows the dosing device to be attached to the process chamber and the guide length of the container guide to be as long as possible.

[0021] According to the invention, the powder container is movably mounted on the container guide. The powder container is designed to move or deflect along the conveying axis beyond the container guide. In other words, the powder container can be pushed beyond the guide end. The dosing device can thus be extended in an extendable manner to introduce the powder container into the process chamber, for example, via a process chamber opening.

[0022] In summary, the dosing device according to the invention is designed to be arranged outside a process chamber on an additive manufacturing device. In order to be able to convey the required process powder into the process chamber during the production of a workpiece within the additive manufacturing device, the dosing device is designed to be linearly movable. The powder container can thus be guided from outside the process chamber into the process chamber in order to provide the required process powder. In other words, only a part of the dosing device is moved into the process chamber for a short period of time to provide the process powder. The process chamber can thus be kept particularly small in size. Furthermore, the dosing device can be moved out of the process chamber during production, thereby ensuring a turbulence-free protective gas flow.

[0023] In a preferred embodiment, the dosing device has a longitudinal drive. The longitudinal drive is typically designed to move the powder container along the conveying axis. The longitudinal drive can be driven hydraulically, pneumatically, and / or electrically, for example. The longitudinal drive is preferably designed as a belt drive. By means of a longitudinal drive, the powder container can be moved with particular precision and control, whereby the conveyance of the process powder can be precisely coordinated with a manufacturing process in the process chamber. The longitudinal drive is preferably arranged or attached to the guide carriage. Particularly preferably, the longitudinal drive is moved along with the guide carriage. This allows the drive and the dosing device to be kept compact.Further preferred is an embodiment of the dosing device in which the powder cavity has at least one vertically upwardly directed powder opening. Typically, the number of powder openings is equal to the number of powder cavities in the powder container. Preferably, each powder cavity has exactly one powder opening. Furthermore, the powder cavity of a powder container can be divided into two or more segments by means of separating webs. These segments can be distributed evenly and / or unevenly across the powder cavity. The division into segments supports an even distribution of the powder over the length of the powder cavity. This is particularly advantageous for long powder cavities. Furthermore, the division of the powder cavity into segments ensures that when the powder container is moved, the powder is only moved within the segments, thus essentially maintaining the even distribution.The vertically upward-facing powder opening allows the powder cavity, or powder container, to be filled by gravity. This allows the powder container to be filled without the need for special or complex technical means.

[0024] In a preferred embodiment of the dosing device, the powder container is arranged on the container guide so that it can rotate about a container rotation axis. In other words, the powder container is designed to be rotatable relative to the container guide. The rotation axis is preferably coordinated with a movement axis of a powder coater of the additive manufacturing device and / or the conveying axis of the dosing device. The powder container can, for example, be designed to be rotatable about a rotation axis running perpendicular to the conveying axis. This can be particularly advantageous if the conveying axis of the dosing device is designed parallel to the direction of movement of the powder coater. By designing the powder container so that it can rotate, the powder opening of the powder cavity can be moved or rotated from a vertically upward position to a vertically downward position.The powder container filled with process powder can be emptied under the influence of gravity when the powder opening is oriented vertically downwards. This makes it possible, among other things, to dispense with an additional powder opening. A preferred embodiment of the dosing device is one in which the container rotation axis is parallel or congruent with the conveying axis. In other words, the powder container can be rotated about a conveying direction. This is particularly advantageous when the conveying direction is perpendicular to the direction of movement of the powder coater or when the powder is fed to the powder coater from the side. In this way, the process powder can be fed in front of the powder coater parallel to the conveying axis, which simplifies subsequent distribution by the powder coater.

[0025] In a particularly preferred embodiment, the dosing device has a rotary drive. The rotary drive is typically designed to rotate the powder container about the container's rotation axis. The rotary drive can be driven hydraulically, pneumatically, and / or electrically, for example. For example, the rotary drive can be designed as an electric stepper motor. The rotary drive is preferably designed as a pneumatic rotary actuator. By means of a rotary drive, the powder can be fed mechanically, in particular automatically. The rotary drive is preferably arranged or attached to the guide carriage. The rotary drive is preferably moved along with the guide carriage. This allows the dosing device to be kept even more compact.

[0026] Preferably, a single rotary drive is designed to rotate all of the powder containers. For this purpose, the rotary drive can have a gear, for example a pinion and / or a belt, via which the powder containers are coupled to one another. The rotary drive is particularly preferably designed to rotate the powder containers individually, in particular independently of one another. This allows filling, conveying, and / or emptying of the powder containers to take place particularly efficiently. In a preferred embodiment of the dosing device, the at least one powder container is designed as a shaft. In other words, the powder container has a substantially cylindrical outer geometry. This allows the powder container to be designed to be particularly rigid. Furthermore, the container cross-section can be kept small in relation to a shaft volume. This favors the formation of a process chamber opening with a small cross-section on the process chamber.This allows the process chamber opening to be sealed using technically simple sealing means. In particular, the powder container is designed as a hollow shaft. This allows the weight of the powder container to be kept low. In this case, the interior of the hollow shaft preferably forms the powder cavity.

[0027] In a preferred embodiment, the dosing device comprises a weighing unit. The weighing unit is typically designed to determine the process powder contained in the powder container. For this purpose, it can be provided, for example, that the entire dosing device is weighed by means of the weighing unit. The process powder contained in the powder container can also be determined, for example, by calculating the difference between a weight of the dosing device before filling and a weight of the dosing device after or during filling. By determining the process powder contained in the powder container, the dosing of the process powder can be precisely matched to the amount of powder required in the process chamber. This can prevent overdosing and / or underdosing of the process powder.

[0028] In a preferred embodiment of the dosing device, the weighing unit has at least one measuring sensor. The measuring sensor is preferably designed to weigh the powder container. The dosing device preferably has at least two measuring sensors. Particularly preferably, the dosing device has two measuring sensors per powder container. The measuring sensors are typically arranged at opposite ends of the respective powder container to be measured. By weighing the powder container, the accuracy in determining the process powder contained in the powder container can be increased, since this does not include the total mass of the dosing device.

[0029] A particularly preferred embodiment of the dosing device is one in which the measuring sensor is designed for temporary placement on the test container. In other words, the measuring sensor is arranged on the powder container solely for measuring the powder container weight. If no measurement is being taken, the measuring sensor is arranged at a distance from the test container. This can prevent a collision of the test container and / or the guide carriage with the weighing unit. Typically, the measuring sensor is designed for vertical placement. This allows the measuring sensor to be arranged on the test container against the effect of gravity.

[0030] Preferably, the measuring sensor is mounted on the test container using an actuator. An actuator can further increase the degree of machine automation.

[0031] The dosing device can provide for the test container to be designed to be deflectable in the vertical direction from a storage position. In other words, the test container is mounted via a vertical floating bearing. To measure the powder container weight, the powder container can be lifted by the weighing unit in this case. Preferably, the test container is designed to be lifted by 0.5 millimeters or more, particularly preferably by 1 millimeter or more. This advantageously allows only the weight of the powder container to act on the measuring sensors, allowing the weight measurement of the powder container to be carried out even more accurately.

[0032] In a preferred embodiment, the dosing device comprises at least two powder containers, each with at least one powder cavity. The powder containers can be arranged parallel to one another.

[0033] A preferred embodiment of the dosing device is one in which the powder containers are designed to be movable together, particularly synchronously, along the container guide or the conveying axis. This allows two powder containers to be guided into the process chamber simultaneously.

[0034] The underlying problem is also solved by an additive manufacturing device. The additive manufacturing device is typically suitable, in particular designed, for layer-by-layer production of at least one workpiece from the process powder by means of region-by-region solidification of the process powder in the process chamber.

[0035] The additive manufacturing device comprises at least one dosing device as described above and below. The additive manufacturing device may comprise two or more dosing devices as described above and below.

[0036] The additive manufacturing device has at least one process chamber. The process chamber is typically designed for manufacturing workpieces from the process powder. The process chamber has at least one closable process chamber opening. In other words, the process chamber has an openable access. The process chamber opening can be predominantly closed to minimize the penetration of ambient gases into the process chamber.

[0037] According to the invention, the dosing device is arranged, in particular secured, to an exterior side of the process chamber. Preferably, the leading end of the container guide is arranged, in particular secured, to the exterior side of the process chamber. In other words, the container guide ends directly at a process chamber wall.

[0038] The dosing device is designed to move the powder container along the conveying axis through the closable process chamber opening into the process chamber. The process chamber opening can be opened for this purpose. Preferably, the dosing device is arranged on the process chamber such that the dosing device closes the process chamber opening. Particularly preferably, the powder container of the dosing device closes the process chamber opening. In this case, the process chamber opening can advantageously be opened by moving the powder container.

[0039] In a preferred embodiment, the additive manufacturing device comprises a working cylinder arranged in the process chamber. The workpiece to be manufactured is typically produced in the process chamber within the working cylinder. The additive manufacturing device can comprise multiple working cylinders. This can facilitate the simultaneous production of multiple workpieces.

[0040] Preferably, in conjunction with multiple dosing devices, the additive manufacturing device comprises at least one dosing device on opposite sides of the working cylinder. This allows the process powder to be supplied to the process chamber at multiple locations, enabling even more effective dosing.

[0041] According to the embodiment, the additive manufacturing device also comprises a powder coater for distributing the process powder in the working cylinder. The powder coater is typically designed to be movable along the coater axis above the working cylinder. Preferably, the coater axis runs perpendicular to the conveying axis of the dosing device. This allows the process powder to be distributed by the powder coater to be emptied along the coater axis in front of and / or behind the powder coater. The powder coater can thus distribute the process powder particularly easily by moving it along the coater axis.

[0042] In a preferred embodiment of the additive manufacturing device, the dosing device for emptying the powder container is designed above the powder coater. Emptying above the powder container can be carried out particularly easily under the influence of gravity. This eliminates the need for alternative technical means for providing the process powder, for example, a lifting device for feeding process powder from below.

[0043] In a preferred embodiment of the additive manufacturing device, the powder coater has a discharge channel. The discharge channel is preferably formed by the powder coater. Further preferably, the discharge channel is designed to accommodate the powder container during movement within the process chamber. A discharge channel can thus provide effective protection against a process flow within the process chamber. This prevents the process powder from being blown away or blown out of the powder container by the process flow.

[0044] The underlying problem can also be solved by a dosing method. The dosing method is suitable, in particular designed, for conveying process powder into the additive manufacturing device described above and below. The dosing method comprises the following method steps:

[0045] In a first process step, the powder container is filled with process powder. In other words, the process powder is fed into the respective powder cavity via the corresponding powder opening. The one or more powder openings of the corresponding powder cavity are typically directed vertically upwards.

[0046] Preferably, all powder containers are filled with process powder. The powder containers can be filled sequentially. Preferably, the powder containers are filled outside the process chamber, thus not interfering with the additive manufacturing process within the process chamber.

[0047] In a further method step, the powder container is moved through the process chamber opening along a conveying axis into the process chamber. Preferably, the guide carriage is set in motion along the container guide by means of a longitudinal drive, whereby the powder containers arranged on the guide carriage are guided into the process chamber in the conveying direction.

[0048] In one method step, the at least one powder cavity of at least one powder container is emptied by rotating the powder container about the container's rotation axis. It can be provided that all powder cavities, in particular of all powder containers, are emptied simultaneously.

[0049] A further process step involves moving the powder container out of the process chamber along the conveying axis. In other words, the dosing device is moved back to its starting position, and the dosing process can be performed again.

[0050] In a preferred embodiment of the dosing method, the powder container is filled by measuring the weight of the process powder contained in the container. This allows the required amount of powder to be precisely dosed at the powder coater 24.

[0051] Further features and advantages of the invention will become apparent from the description, the claims, and the drawings. According to the invention, the above-mentioned and further-described features can be used individually or in combination in any convenient way. The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature for describing the invention.

[0052] Detailed description of the invention and drawing

[0053] Fig. 1 shows a perspective view of an additive manufacturing device with a process chamber and a powder coater. Fig. 2 shows the additive manufacturing device from Fig. 1 in a rear view of the process chamber with a dosing device.

[0054] Fig. 3 shows the additive manufacturing device from Fig. 1 with the powder container of the dosing device accommodated in a discharge channel.

[0055] Fig. 4 shows a detailed view of the powder coater with the powder containers of the dosing device arranged therein.

[0056] Fig. 5 shows a further detailed view of the powder coater from Fig. 4 in a sectional view.

[0057] Fig. 6 shows the dosing device from the previous figures in a sectional detailed view.

[0058] Fig. 7 shows a detailed view of another embodiment of a dosing device.

[0059] Fig. 8 shows a schematic representation of the dosing process.

[0060] Fig. 1 shows an additive manufacturing device 10 according to the invention with a dosing device 12 (see Fig. 2) and a process chamber 14.

[0061] A working cylinder 16 can be arranged in the process chamber 14, in which a workpiece (not shown in detail) can be manufactured according to an additive manufacturing process, for example, a powder-bed-based laser melting process (laser metal fusion; LMF). According to the exemplary manufacturing process, process powder (not shown in detail) can be supplied to the process chamber 14 or the working cylinder 16, wherein a workpiece can be manufactured layer by layer by melting the process powder. For this purpose, the additive manufacturing device 10 can have a laser beam unit 18, which—as schematically shown—can be arranged on an outer side of the process chamber 14.

[0062] During the production of the workpiece, the working cylinder 16 can be lowered in stages starting from a working plane 20. With each lowering of the working cylinder 16, a working recess (not shown in detail) is created above the working cylinder 16 relative to the working plane 20, which recess can be filled with process powder by a powder coater 24. For this purpose, the powder coater 24 can be moved translationally along the working plane 20 above the working cylinder 16, along a coater axis 26. The working cylinder 16 filled with the process powder can then be irradiated by the laser beam unit 18, whereby the process powder can be at least partially melted according to the workpiece to be produced. After irradiation by the laser beam unit 18 is complete, the working cylinder 16 can be lowered again and the process repeated until the workpiece is completely produced.

[0063] The powder coater 24 typically has a wiper lip 28. The wiper lip 28 is typically in permanent contact with the working plane 20. However, it can also be provided that the wiper lip 28 has a defined distance, e.g., 1 millimeter, from the working plane 20 in order to compensate for unevenness in a process chamber floor. The wiper lip 28 can ensure an even distribution of process powder in the work cavity. Furthermore, the wiper lip 28 can remove excess process powder from the working cylinder 16, so that a powder layer is formed in the working cylinder 16 or the process chamber that is flush with or parallel to the working plane 20. The wiper lip 28 is preferably made of an elastomer. This allows the wiper lip 28 to perform the wiper and distribution functions particularly reliably.

[0064] The powder coater 24 can, as shown, have a first wind deflector 30 and a second wind deflector 32. Typically, a first process powder chamber 34 is formed on the powder coater 24 between the first wind deflector 30 and the wiper lip 28, and a second process powder chamber 36 is formed between the second wind deflector 32 and the wiper lip 28. The first process powder chamber 34 and the second process powder chamber 36 serve to supply the process powder in front of the wiper lip 28 depending on the direction of movement of the powder coater 24. For example, it can be provided that process powder is provided to the powder coater in the first process powder chamber 34 according to the position shown in Fig. 1. By moving the powder coater 24, the process powder provided in the first process powder chamber 34 can be distributed over the working cylinder 16 until a powder layer flush with the working plane 20 is formed.

[0065] The second process powder chamber 36 can be provided to form a flush powder layer when the powder coater 24 is moved in an opposite direction along the coater axis 26. Preferably, the second process powder chamber 36 is filled with process powder simultaneously with the first process powder chamber 34 or immediately after the first process powder chamber 34 is filled. Particularly preferably, at least the second process powder chamber 36 has a retaining means that can prevent the release of the process powder.

[0066] The first and second wind deflectors 30, 32 preferably prevent the blowing out of process powder by process flows (not shown in detail) within the process chamber 14.

[0067] The process chamber 12 typically has a process chamber wall 38. The process chamber wall 38 preferably completely surrounds the process chamber 12 and forms a process chamber volume.

[0068] Fig. 2 shows the additive manufacturing device 10 in a view of the outside of the process chamber 14, or the process chamber wall 38.

[0069] As shown, the process chamber 14 has a process chamber opening 40 formed on the process chamber wall 38. In the embodiment shown, the process chamber opening 40 can be closed by the dosing device 12. In the present case, a closeable process chamber opening 40 means a gas-tight contact of the dosing device 12 with the process chamber wall 38. The dosing device 12 is arranged on an outer side 42 of the process chamber 14.

[0070] The dosing device 12 can—as shown—have two powder containers 44. The powder containers 44 each have at least one powder cavity 46 designed to hold the process powder. The powder cavity of a powder container can be divided into two or more segments 47 by means of separating webs 45 (see Fig. 7).

[0071] The dosing device 12 further comprises a container guide 48. The container guide 48 is designed for the linear movement of at least one powder container 44 along a conveying axis 50 of the dosing device 12. The length of the container guide 48 preferably corresponds to the penetration depth of the powder container 44 into the process chamber 14.

[0072] The container guide 48 is arranged with a guide end 52 on the process chamber 14, or the outer side 42 of the process chamber wall 38. The powder containers 44 are typically arranged parallel to the container guide 48. By moving the powder containers 44 along or parallel to the conveying axis 52, the powder containers 44 can be introduced into the process chamber 14 through the closable process chamber opening 40. The powder containers 44 can be deflected beyond the guide end 52 of the container guide 48. In other words, the powder containers 44 are arranged on the container guide 48 in a telescopic or expandable manner.

[0073] According to the illustrated embodiment, the powder containers 44 can be arranged on a guide carriage 54. The guide carriage 54 is preferably movably arranged on the container guide 48.

[0074] The dosing device 12 may have a longitudinal drive 56. The longitudinal drive 56 is typically designed to move the powder container 44 or the guide carriage 54 along the conveying axis 50. As shown, the longitudinal drive 56 may be designed as a belt drive 58.

[0075] The dosing device 12 can alternatively or additionally have a rotary drive 60. The rotary drive 60 can be designed to rotate the powder containers 44 about a container rotation axis 62. Preferably, each powder container 44 has its own container rotation axis 62. Particularly preferably, the powder containers 44 are designed to be rotatable independently of one another by the rotary drive 60.

[0076] The rotary drive 60 is preferably designed as an actuator and for transmitting at least half a rotation, particularly preferably a full rotation, to the powder containers 44. In other words, each powder container 44 can be rotated about its respective container rotation axis 62 such that the respective powder cavity 46 can be moved from a vertically upward position to a vertically downward position.

[0077] Typically, the powder cavities 46 each have, in particular exclusively, one powder opening 64. Filling of the powder containers 44 or the powder cavities 46 can thus advantageously take place in the direction of gravity, while the powder containers 44 with their respective powder opening 64 are in a vertically upward position. Emptying of the powder containers 44 or the powder cavities 46 can further advantageously also take place in the direction of gravity, while the powder containers 44 with their respective powder opening 64 are in a vertically downward position.

[0078] Fig. 2 shows the dosing device 12 in a non-deflected state. In other words, the dosing device 12 is located completely outside the process chamber 14, as shown in Fig. 2.

[0079] Fig. 3 shows the additive manufacturing device 10 in a sectional detailed view. The dosing device 12 is in a deflected state. In other words, the powder containers 44 are deflected along the conveying axis 50 such that the powder containers 44 are located completely within the process chamber 14. The powder containers 44 were guided parallel to the container guide 48 (see Fig. 2) along the conveying axis 50 through the process chamber opening 40. As shown, the conveying axis 50 can be configured perpendicular to the coater axis 26.

[0080] The powder containers 44, in particular the powder cavities 46, preferably have the same dimensions as the powder coater 24, in particular the wiper lip 28, along the conveying direction 50. This allows powder to be supplied over the entire extent of the powder coater 24. Typically, the extent of the powder coater 24 is adapted to a dimension of the working cylinder 16 (see Fig. 1) perpendicular to the coater axis 26, whereby a particularly effective distribution of the process powder in the working cylinder 16 (see Fig. 1) can be achieved.

[0081] Fig. 4 shows a further sectional detailed view of the additive manufacturing device 10, particularly illustrating the powder coater 24. The dosing device 12 is partially arranged in the process chamber 14 of the additive manufacturing device 10 through the powder containers 44.

[0082] According to the illustrated embodiment, the powder containers 44 can be arranged above the wiping lip 28 of the powder coater 24. Preferably, the powder containers 44 are arranged centrally above the wiping lip 28. If the dosing device 12 has only one powder container 44, this can be arranged centrally above the wiping lip 28.

[0083] Particularly preferably, one powder container 44 is arranged above the first process powder chamber 34 and another powder container 44 is arranged above the second process powder chamber 36. This allows the process powder to be supplied from both sides of the wiper lip 28. As shown, the dosing device 12 can have a container holder 66. The container holder 66 is preferably designed to support the powder containers 44. This can prevent the powder containers 44 from bending. Furthermore, the container holder 66 can effectively prevent process powder from accidentally reaching the side of the wiper lip 28 facing away from the powder container 44. For this purpose, the container holder 66 can have a foot section 67 that widens in the vertical direction.Alternatively or additionally, it can be provided that the wiper lip 28 has a head section 68 tapering in the vertical direction, which prevents process powder from reaching the other side of the wiper lip 28 during emptying.

[0084] According to the embodiment shown, each powder container 44 can be rotated about its container rotation axis 62, whereby the corresponding powder cavity 46 with the corresponding powder opening 64 is moved from a vertically upward position to a vertically downward position. The process powder contained in the respective powder cavity 46 can be emptied onto the corresponding side of the wiping lip 28 by rotation.

[0085] In a particular embodiment of the additive manufacturing device 10, the powder coater 24 has a discharge channel 70. The discharge channel 70 can preferably be formed on the powder coater 24. The discharge channel 70 is designed to accommodate the dosing device 12 or the powder container 44 within the process chamber 14. In other words, the discharge channel 70 represents a housing for the powder containers 44. The powder containers 44 are movable within the discharge channel 70. The discharge channel 70 can prevent a process flow (not shown) formed within the process chamber 14 from removing or carrying away the process powder entrained in the process containers 44.

[0086] Particularly preferably, the discharge channel 70 is formed between the first and second wind deflectors 30, 32. This provides effective protection against flow-induced removal of the process powder by the process flow, even after the process powder has been emptied from the powder cavities 46.

[0087] Fig. 5 shows a further sectional detailed view of the powder coater 24 of the additive manufacturing device 10. The powder containers 44 of the dosing device 12 are arranged in the process chamber 14.

[0088] As shown, the powder coater 24 can have or form a centering section 72. The centering section 72 is typically formed on a side of the powder coater 24 facing away from the process chamber opening 40 (see Fig. 3). The centering section 72 preferably projects along the conveying axis 50 in the direction of the dosing device 12. The dosing device 12—here the container holder 66—preferably forms a centering recess 74 complementary to the centering section 72 and / or a complementary centering projection. The centering section 72 is formed in conjunction with the centering recess 74 for centering the dosing device 12 or the powder container 44 within the process chamber 14.According to the illustrated embodiment, the powder containers 44 are supported on the powder coater 24 by means of the container holder 66 when fully inserted into the process chamber 14. This can prevent the powder containers 44 from bending even more effectively.

[0089] Fig. 6 shows a sectional detailed view of the dosing device 12.

[0090] The dosing device 12 has the container guide 48 and the powder containers 44 arranged on the container guide 48 via the guide carriage 54.

[0091] In a preferred embodiment, the dosing device 12—as shown—may include a weighing unit 76. The weighing unit 76 is designed to determine the process powder contained in the powder containers 44 or in the powder cavities 46.

[0092] For this purpose, the weighing unit 76 can be configured to weigh each individual powder container 44. Typically, the weighing unit 76 has at least one measuring sensor 78, particularly preferably two measuring sensors 78 per powder container 44 (see also Fig. 2).

[0093] According to the illustrated embodiment, the weighing unit 76, or each individual measuring sensor 78, can be designed to be movable in the vertical direction along a measuring axis 80. In other words, the weighing unit 76 can be moved in the vertical direction toward the powder containers 44. This allows only temporary contact between the weighing unit 76 and the powder containers 44. In other words, after the measurement has been taken, the weighing unit 76 can be moved out of a movement space of the powder containers 44 and / or the guide carriage 54, thereby preventing a collision. The weighing unit 76 can be moved along the measuring axis 80, for example, by means of corresponding actuators (not shown).

[0094] To weigh the corresponding powder container 44, the measuring sensor 78 is first moved along the measuring axis 80 toward the powder container 44 until the measuring sensor 78 is in contact with the powder container 44. Contact between the measuring sensor 78 and the powder container 44 can be detected, for example, by applying force to the measuring sensor 78. The powder container 44 can then be lifted by the measuring sensor 44 along the measuring axis 80. In other words, the powder container 44 is detached vertically from the rest of the dosing device 12. This enables the exclusive weight measurement of the powder container 44, including the process powder contained therein.

[0095] To enable the powder container 44 to be lifted, the dosing device 12 typically has a floating bearing arrangement 82 in the vertical direction. Starting from a lower vertical stop 84, the floating bearing arrangement 82 allows only a relative movement in the vertical direction up to an upper vertical stop 86. The floating bearing arrangement 82 typically acts on a rotary coupling 87 between the powder containers 44 and the rotary drive 60 to enable the corresponding powder container 44 to be released.

[0096] After weighing the powder container 44, the weighing unit 76 can be spaced apart from the powder container 44 along the measuring axis 80. This causes the powder container 44 to rest against the lower vertical stop 84.

[0097] Fig. 7 shows a further schematic detailed representation of the powder container 44.

[0098] In this embodiment, the powder container 44 has a plurality of separating webs 45 that are incorporated into the powder cavity 46. Thus, the powder cavity 46 is divided into a plurality of segments 47. The separating webs 45 can be distributed evenly and / or unevenly spaced throughout the powder cavity 46.

[0099] Fig. 8 shows a schematic representation of a dosing method 88 according to the invention for conveying process powder into an additive manufacturing device 10 (see Fig. 1). The dosing method 88 comprises the following method steps, which are explained with reference to the preceding figures:

[0100] In a first method step 90, a powder container 44 is filled with process powder. Preferably, all powder containers 44 are filled with process powder in method step 90.

[0101] Typically, the powder container 44 is filled under the influence of gravity into the corresponding powder cavity 46 of the powder container 44. For example, the powder container 44 can be filled using a vibrating conveyor ramp (not shown). Filling can take place outside the process chamber 14. A powder opening 64 of the corresponding powder cavity 46 is directed vertically upward.

[0102] In a further method step 92, the powder container 44 filled with process powder is moved through the process chamber opening 40 along the conveying axis 50 into the process chamber 14.

[0103] Preferably, the guide carriage 54 is set in motion along the container guide 48 by means of a longitudinal drive 56, whereby the powder containers 44 arranged on the guide carriage 54 are guided in the conveying direction 50 into the process chamber 14.

[0104] A further method step 94 provides for the emptying of at least one powder cavity 46 of at least one powder container 44 by rotating the corresponding powder container 44 about its container rotation axis 62.

[0105] Emptying typically takes place into a first powder chamber 34 of the powder coater 24.

[0106] In a further method step 96, the powder container 44 is moved along the conveying axis 50 out of the process chamber 14. In other words, the dosing device 12 is moved back to its starting position, and the dosing process 88 can be performed again.

[0107] In a preferred embodiment of the dosing method 88, it can be provided that the filling of the powder container 44 takes place by measuring the weight of the process powder contained in the powder container 44. This allows the required amount of powder to be precisely dosed at the powder coater 24.

[0108] Manufacturing device 10; Longitudinal drive 56;

[0109] Dosing device 12; Belt drive 58;

[0110] Process chamber 14; rotary drive 60;

[0111] Working cylinder 16; container rotation axis 62;

[0112] Laser beam unit 18; powder opening 64;

[0113] Working level 20; container holder 66;

[0114] Powder coater 24; Foot section 67;

[0115] Coater axis 26; head section 68;

[0116] Wiper lip 28; discharge channel 70; first wind deflector 30; centering section 72; second wind deflector 32; centering recess 74; first process powder chamber 34; weighing unit 76; second process powder chamber 36; measuring sensor 78;

[0117] Process chamber wall 38; measuring axis 80;

[0118] Process chamber opening 40; floating bearing arrangement 82;

[0119] Outer side 42; Lower vertical stop 84;

[0120] Powder container 44; Upper vertical stop 86;

[0121] divider 45; rotary coupling 87;

[0122] Powder cavity 46; Dosing method 88;

[0123] Segment 47; Process step 90;

[0124] Container guide 48; process step 92;

[0125] Conveyor axis 50; process step 94;

[0126] Leading end 52; process step 96.

[0127] Guide carriage 54;

Claims

Dosing device (12) for external arrangement on a process chamber (14) of an additive manufacturing device (10) and for conveying process powder into the process chamber (14), comprising: - at least one powder container (44) with at least one powder cavity (46) designed to receive the process powder; - a container guide (48) for linearly moving the powder container (44) along a conveying axis (50) of the dosing device (12); wherein the powder container (44) is movably arranged on the container guide (48); and wherein the powder container (44) is designed to deflect along the conveying axis (50) beyond the container guide (48). Dosing device (12) according to claim 1, comprising a longitudinal drive (56), wherein the longitudinal drive (56) is designed to move the powder container (44) along the conveying axis (50). Dosing device (12) according to one of claims 1 or 2, wherein the powder cavity (46) has at least one vertically upwardly directed powder opening (64) which enables filling of the powder container (44) in the direction of gravity. Dosing device (12) according to one of the preceding claims, wherein the powder container (44) is arranged on the container guide (48) so as to be rotatable about a container rotation axis (62).Dosing device (12) according to claim 4, wherein the container rotation axis (62) is parallel or congruent with the conveying axis (50). Dosing device (12) according to claim 4 or 5, comprising a rotary drive (60), wherein the rotary drive (60) is designed to rotate the powder container (44) about the container rotation axis (62). Dosing device (12) according to one of the preceding claims, wherein the powder container (44) is designed as a shaft, in particular as a hollow shaft. Dosing device (12) according to one of the preceding claims, comprising a weighing unit (76), wherein the weighing unit (76) is designed to determine the process powder contained in the powder container (44). Dosing device (12) according to claim 8, wherein the weighing unit (76) has at least one measuring sensor (78) designed to weigh the powder container (44). Dosing device (12) according to claim 9, wherein the measuring sensor (78) is designed to be temporarily arranged on the test container (44) in a vertical direction, in particular by means of an actuator. Dosing device (12) according to one of the preceding claims, comprising at least two powder containers (44), each having at least one powder cavity (46), wherein the powder containers (44) are arranged parallel to one another.Dosing device (12) according to claim 11, wherein the powder containers (44) are designed to be movable together along the conveying axis (50). Dosing device (12) according to one of the preceding claims, wherein the at least one powder cavity (46) is divided into two or more segments (47), and wherein the segments (47) are preferably arranged at a uniform distance from one another. Additive manufacturing device (10) for the layer-by-layer production of at least one workpiece from a process powder by means of regional solidification of a process powder in a process chamber (14), comprising a dosing device (12) according to one of the preceding claims; wherein the process chamber (14) has at least one closable process chamber opening (40); wherein the dosing device (12) is arranged on an outer side (42) of the process chamber (14); and. wherein the dosing device (12) is configured to move the powder container (44) along the conveying axis (50) through the closable process chamber opening (40) into the process chamber (14). Additive manufacturing device (10) according to claim 14, further comprising - a working cylinder (16) arranged in the process chamber (14), wherein the process chamber (14) is designed to manufacture the workpiece within the working cylinder (16); - a powder coater (24) for distributing the process powder in the working cylinder (16); wherein the powder coater (24) is designed to be movable along a coater axis (26) above the working cylinder (16); wherein the coater axis (26) runs perpendicular to the conveying axis (50). Additive manufacturing device (10) according to claim 15, wherein the dosing device (12) for emptying the powder container (44) is designed above the powder coater (24). Additive manufacturing device (10) according to claim 15 or 16, wherein the powder coater (24) forms a discharge channel (70), wherein the powder container (44) is designed to be movable in the process chamber (14) within the discharge channel (70). Dosing method (88) for conveying process powder into a process chamber (14) of an additive manufacturing device (10) according to claim 14, comprising the method steps: - filling (90) the powder container (44) with process powder; - moving (92) the powder container (44) through the process chamber opening (40) along a conveying axis (50) into the process chamber (14); - Emptying (94) the powder cavity (46) by rotating the powder container (44) about the container rotation axis (62); - Moving (96) the powder container (44) along the conveying axis (50) out of the process chamber (14). Dosing method (88) according to claim 18, wherein the filling of the powder container (44) is carried out by measuring the weight of the process powder located in the powder container (44).

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