Suction unit for an exhaust device and additive manufacturing device comprising an exhaust device

Abstract

The invention relates to a suction unit (26; 26a, 26b) for an exhaust device (12) for extracting a process gas out of a process chamber (14) of an additive manufacturing device (10), comprising a first suction head (36a) and a second suction head (36b) for suctioning the process gas within the process chamber (14), an exhaust channel (34) for discharging the process gases suctioned by the suction heads (36; 36a-e), wherein the first suction head (36a) is arranged or formed on the exhaust channel (34) in front of the second suction head (36b) in an exhaust direction (38), wherein the exhaust channel (34) has a first channel segment (48a) with a first feed cross-section (50a) and a second channel segment (48b) with a second feed cross-section, wherein the first feed cross-section (50a) has a flow cross-sectional area that is greater than a flow cross-sectional area of the second feed cross-section (50b), and wherein the first suction head (36a) feeds into the first channel segment (48a) and the second suction head (36b) and the first channel segment (48a) feed into the second channel segment (48b).

Description

[0001] Suction unit for a suction device and additive manufacturing device with a suction device

[0002] Background of the invention

[0003] The invention relates to a suction unit for a suction device. The invention also relates to an additive manufacturing device with a suction device having a suction unit.

[0004] Particularly in additive manufacturing processes such as powder bed-based laser beam melting (Laser Powder Bed Fusion, LPBF), production takes place in a protective gas atmosphere to ensure high manufacturing accuracy.

[0005] To create the protective gas atmosphere, the so-called "inerting", a process chamber of the additive manufacturing device is typically supplied with a process gas or protective gas, which is fed into the interior of the process chamber via a process gas supply unit.

[0006] During additive manufacturing, however, the process gas is mixed or contaminated with suspended particles, such as dispersed process powder, and / or smoke produced during production, which reduces the quality of the additive manufacturing process.

[0007] Therefore, the state of the art typically provides for the contaminated process gas to be extracted from the process chamber via an extraction device. This places high demands on the extraction device. In particular, the extraction device must ensure the most uniform and turbulence-free process chamber flow possible to enable effective extraction of the contaminated process gas and prevent the stirring up of further process powder and the diversion of smoke and other process emissions toward the powder bed.

[0008] In addition, special requirements are placed on extraction devices that feature a suction unit that can move within the process chamber. Such extraction devices are used, for example, in additive manufacturing systems that allow for parallel coating with process powder and solidification of the process powder in a working cylinder. The suction unit is moved in the vicinity of the working cylinder to be coated in order to extract any dispersed process powder as quickly as possible.

[0009] Object of the invention

[0010] It is therefore an object of the invention to provide a device for the turbulence-free and uniform extraction of process gas from a process chamber of an additive manufacturing device.

[0011] Description of the invention

[0012] This object is achieved according to the invention by an intake unit according to patent claim 1. The object is further achieved by an additive manufacturing device according to patent claim 15. The subclaims relate to preferred embodiments of the invention.

[0013] According to the invention, a suction unit is provided. The suction unit is suitable or designed for arrangement on a suction device. In other words, a suction device can be equipped with the suction unit. The suction unit can have a pipe connection for this purpose. This enables easy retrofitting or conversion of existing suction devices.

[0014] The suction unit is further suitable or designed for extracting a process gas from a process chamber of an additive manufacturing device. Furthermore, the suction unit can be designed for extracting various gaseous media. Typically, the suction unit is designed for extracting suspended particles contained in the gaseous medium, e.g., process powder.

[0015] The intake unit has a first intake funnel and a second intake funnel. In other words, the intake unit has at least two intake funnels. The intake funnels are designed to draw in the process gas within the process chamber.

[0016] Each of the intake funnels typically has an inflow surface through which the drawn-in process gas flows into the respective intake funnel. Each of the intake funnels can also have an outflow surface through which the drawn-in process gas can be discharged from the respective intake funnel. The intake funnels typically each have a flow cross-section that tapers from the inflow surface to the outflow surface.

[0017] According to the invention, the suction unit also has an extraction channel. The extraction channel is designed to discharge the process gases drawn in through the intake funnels. In other words, the extraction channel is designed for arrangement or attachment to the outflow surfaces of the intake funnels. Typically, the extraction channel is designed for arrangement, in particular in a gas-tight manner, on an extraction device.

[0018] According to the invention, the first intake funnel is arranged or fastened to the extraction channel upstream of the second intake funnel in a suction direction. Typically, the first intake funnel is further away from the pipe connection than the second intake funnel. Typically, the process gas sucked in through the first intake funnel travels a longer flow path within the extraction channel than the process gas sucked in through the second intake funnel. The extraction channel has a first channel segment with a first opening cross-section and a second channel segment with a second opening cross-section. According to the invention, the first intake funnel opens into the first channel segment. In other words, the first channel segment with the first opening cross-section can be arranged on the outflow surface of the first intake funnel. Furthermore, the first channel segment and the second intake funnel open into the second channel segment.

[0019] The first mouth cross-section of the first channel segment has a flow cross-sectional area that is larger than a flow cross-sectional area of ​​the second mouth cross-section of the second channel segment.

[0020] In summary, an intake unit is provided that proposes the extraction of process gas with at least two intake funnels. The funnel-shaped design promotes the extraction of process gas from a wide area surrounding the intake funnel. Furthermore, it is proposed to compensate for a flow-path-related pressure loss within the extraction channel by adapting the outlet cross-section to the respective channel segment, thereby achieving a uniform process volume flow per intake funnel. The intake unit according to the invention thus enables uniform extraction of process gas from the process chamber at relatively low flow velocities. Suction-related stirring of the process powder as well as the deflection of smoke and process emissions toward the powder bed due to turbulence in the process chamber flow can be effectively avoided.

[0021] In a preferred embodiment, the suction unit has at least one further channel segment and at least one further suction funnel. The suction unit preferably has several, in particular three, further channel segments and a corresponding number of suction funnels. A larger number of channel segments and suction funnels promotes an even more uniform suction of process gas. The further channel segment is preferably arranged or formed on the suction channel behind the first channel segment and the second channel segment in the suction direction. Further preferably, the channel segment located in front of the further channel segment in the suction direction and the further suction funnel open into the further channel segment. For example, the second channel segment and a third suction funnel can open into a third channel segment. Furthermore, for example, a fourth channel segment and a fifth suction funnel can open into a fifth channel segment.

[0022] A preferred embodiment of the intake unit is one in which the first channel segment extends into the second channel segment. In other words, the first channel segment overlaps the second channel segment along a longitudinal axis of the extraction channel. In this case, the first channel segment can be used to guide the process gas flow through the second intake funnel. This promotes a low-turbulence merging of the individual process gas flows through the intake funnels within the extraction channel.

[0023] A preferred development of the embodiment provides that several, in particular all, channel segments extend into the channel segment following the respective channel segment in the suction direction. In other words, adjacent channel segments extend into one another in the suction direction. This can further promote low-turbulence flow convergence.

[0024] In a preferred embodiment of the suction unit, the outlet cross-sections have a decreasing flow cross-sectional area in the suction direction of the suction channel. In other words, the flow cross-sectional area of ​​an outlet cross-section is increasingly larger with increasing flow path within the suction channel. This allows the pressure loss at the suction funnels arranged downstream in the suction direction to be increased in order to ensure the most even volume flow distribution across all suction funnels possible. Alternatively or additionally, the suction channel is designed such that the channel cross-sectional area of ​​the suction channel increases in a suction direction of the suction channel. In other words, the flow cross-section of the suction channel increases in the suction direction.This prevents pressure losses caused by the flow merging of the process gas volume flows sucked in through the intake funnels, which further promotes uniform suction.

[0025] A preferred embodiment of the intake unit is one in which at least one outlet cross-section is designed in the shape of a circular sector or annular sector. This allows geometrically induced pressure losses to be kept to a minimum.

[0026] Further preferred is an embodiment of the intake unit in which the first channel segment delimits the second intake funnel. In other words, the first channel segment forms a wall of the second intake funnel. This allows the intake unit to be manufactured in a more resource-efficient manner.

[0027] In a preferred embodiment of the intake unit, the intake funnels are each delimited along a channel's longitudinal axis by two segment walls, wherein the segment walls are formed, in particular, orthogonally to the channel's longitudinal axis. This allows an intake area of ​​the respective intake funnel to be effectively delimited from the at least one other intake funnel. Adjacent intake funnels along the channel's longitudinal axis preferably have a common segment wall. This allows the intake unit to be manufactured in a cost-effective and resource-efficient manner.

[0028] A preferred development of the intake unit provides that the segment walls are designed in the shape of a circular sector or annular sector. This allows the inflow area of ​​the intake funnel to be designed with particularly low pressure loss. In a preferred embodiment of the intake unit, the intake funnels each have a first funnel wall and a second funnel wall. The funnel walls preferably form a funnel angle. The funnel angle can be between 30° and 270°, preferably between 45° and 135°, particularly preferably between 80° and 100°. The funnel angle can limit the inflow area of ​​the intake funnel in the circumferential direction of the longitudinal axis of the duct.

[0029] A further preferred embodiment of the intake unit is one in which the at least two intake funnels have at least one common funnel wall. Preferably, all intake funnels have at least one common funnel wall. In other words, at least one of the funnel walls, in particular both funnel walls, can extend over all intake funnels of the intake unit. This allows the intake unit to be manufactured even more cost-effectively.

[0030] In a preferred embodiment of the intake unit, the first and / or second intake funnels, in particular all intake funnels, are designed as a cylindrical sector or a hollow cylindrical sector. The inventors have recognized that a cylindrical sector or hollow cylindrical sector design of the intake funnels is particularly effective with regard to uniform and low-turbulence intake of the process gas.

[0031] The intake funnels can each have an extension along the channel's longitudinal axis of at least 50 millimeters, preferably at least 100 millimeters, particularly preferably at least 250 millimeters. Typically, the extension of the intake funnels along the channel's longitudinal axis depends on the process chamber width and the number of intake funnels.

[0032] The channel segments can each have a channel segment extension along the channel longitudinal axis. The channel segments can have a mean channel segment radius. The mean channel segment radius can be related to a change in the channel segment radius of the respective channel segment along the channel longitudinal axis and / or a change in the channel segment radius of the respective channel segment in the circumferential direction of the channel segment. Preferably, each channel segment has a channel segment ratio between the channel segment extension and the mean channel segment radius of the respective channel segment. The channel segment ratio can be at least 1:1, preferably at least 2:1, particularly preferably at least 3:1. For example, if a channel segment has a channel segment extension of 90 millimeters, the mean channel segment radius with a channel segment ratio of 3:1 is exactly 30 millimeters.

[0033] Further preferred is an embodiment of the intake unit in which at least two intake funnels have the same extension along the longitudinal axis of the channel. Preferably, all intake funnels of the intake unit have the same extension along the longitudinal axis of the channel. This allows for even more uniform extraction of process gas from the process chamber.

[0034] The underlying problem is also solved by an additive manufacturing device. The additive manufacturing device has a process chamber and an extraction device for extracting a process gas from the process chamber of the additive manufacturing device.

[0035] According to the invention, the suction device comprises at least one suction unit, as described above and below, which is arranged on the suction device. The suction unit is arranged at least predominantly within the process chamber.

[0036] In a preferred embodiment, the additive manufacturing device further comprises a coating unit for distributing process powder in a working plane of the additive manufacturing device. The suction unit is preferably arranged or formed on the coating unit. The suction unit is designed to follow a movement of the coating unit along a movement axis. This allows the suction unit to be positioned in the vicinity of the powder coating and directly suck in swirled process powder.

[0037] A preferred development of the additive manufacturing device is one in which the additive manufacturing device has at least two suction units as described above and below. Preferably, both suction units are arranged or formed on the coating unit. Particularly preferably, a first suction unit is arranged or formed upstream of the coating unit along the movement axis of the coating unit, and a second suction unit is arranged or formed downstream of the coating unit along the movement axis of the coating unit. This allows for the formation of a particularly extensive suction area.

[0038] In a preferred embodiment of the additive manufacturing device in conjunction with a suction unit having a hopper wall, the hopper wall of at least one suction hopper is configured parallel to the working plane of the additive manufacturing device. This allows suspended particles and / or process powder accumulated on the working plane to be collected through the hopper wall.

[0039] 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.

[0040] Detailed description of the invention and drawing

[0041] Fig. 1 shows a perspective view of an additive manufacturing device with an extraction device comprising two suction units. Fig. 2 shows the additive manufacturing device from Fig. 1 in a perspective detailed view of the suction units arranged on a coating unit of the additive manufacturing device.

[0042] Fig. 3 shows the suction units of the suction device from Figs. 1 and 2 arranged on the coating unit in a representation detached from the additive manufacturing device.

[0043] Fig. 4 shows one of the intake units from Figs. 1 to 3 in a sectional perspective view.

[0044] Fig. 1 shows an additive manufacturing device 10 according to the invention in a sectional view. The additive manufacturing device 10 has an extraction device 12 for extracting process gas (not shown in detail) from a process chamber 14 of the additive manufacturing device 10.

[0045] The process gas can be supplied to the process chamber 14, for example, via a process gas supply unit 16. Furthermore, process gas can be generated during an additive manufacturing process, in particular during a powder-bed-based laser melting (LMF) process, for example in the form of smoke. The process gas to be extracted typically contains suspended particles.

[0046] As shown, the process chamber 14 can have a working cylinder 18. During the additive manufacturing process, the working cylinder 18 is gradually lowered relative to a working plane 20 of the process chamber 14. This creates a working recess (not shown) that is filled with process powder. In a subsequent process step, the process powder located in the working recess is at least partially solidified. For example, a laser unit (not shown in detail) can be used for this purpose. The working cylinder 18 is then lowered again, and additional process powder is fed into the resulting working recess, which is then partially solidified again. The process steps are repeated until a workpiece is completed. The filling of the working recess with process powder is typically carried out by a coating unit 22.The coating unit 22 is moved along a movement axis 24 of the coating unit 22 above the working cylinder 18 in order to distribute the process powder evenly in the working cavity.

[0047] Preferably, the extraction device 12, as shown, is arranged predominantly outside the process chamber 14. This allows the process chamber volume to be inerted to be kept small. According to the illustrated embodiment, the extraction device 12 has two suction units 26 arranged within the process chamber 14 to enable the suction of the process gases.

[0048] The process gas supplied during additive manufacturing via the process gas supply unit 16 can, for example, flow into the process chamber 14 along main flow paths 28 and secondary flow paths 30 and then be extracted from the process chamber 14 by the suction units 26. This can achieve a uniform chamber flow and enable manufacturing under optimal process chamber conditions.

[0049] Fig. 2 shows the additive manufacturing device 10 from Fig. 1 with the coating unit 22 designed to distribute process powder in the working cylinder 18 in a sectional view.

[0050] In the embodiment shown, the suction units 26 of the suction device 12 are arranged or attached to the coating unit 22. In a particular embodiment, at least one of the suction units 26 can be formed on the coating unit 22.

[0051] As shown, the extraction units 26 are arranged upstream and downstream of the coating unit 22 along the movement axis 24 of the coating unit 22. In other words, the extraction units 26 are arranged along the movement axis 24 of the coating unit 22 on opposite sides of the coating unit 22. This facilitates the direction-independent extraction of process gas.

[0052] The suction units 26 or the suction device 12 are designed to follow a movement of the coating unit 22 along the movement axis 24. In other words, the suction units 26 are designed to be movable together with the coating unit 22. For this purpose, the suction device 12 is typically designed to be at least partially movable outside the process chamber 14. The process chamber 14 typically has a movable, for example, displaceable, chamber opening in a process chamber wall 32, through which the suction units 26 protrude into the process chamber 14.

[0053] As shown, each suction unit 26 can extend at least across the entire width of the working cylinder 18 transversely to the movement axis 24. Preferably, each suction unit 26 extends across the entire width of the process chamber 14 transversely to the movement axis 24. This enables a particularly uniform and turbulence-free suction of the process gases.

[0054] The suction units 26 each have a suction channel 34 and—here—a plurality of suction funnels 36. The suction funnels 36 are arranged or formed on the respective suction channel 34 of the respective suction unit 26. For reasons of clarity, only one suction channel 34 and one suction funnel 36 of a suction unit 26 are provided with a reference symbol.

[0055] During suction, the suction device 12 generates a negative overpressure or underpressure in the suction channel 34 relative to the process chamber 14, causing process gas to be sucked in at each suction funnel 36 of the respective suction unit 26. The sucked-in process gas is then discharged from the process chamber 14 in a suction direction 38 via the suction channel 34.

[0056] Fig. 3 shows the coating unit 22 and the suction units 26 from Fig. 2, which are also referred to below as the first suction unit 26a and the second suction unit 26b. For reasons of clarity, only the components of the first suction unit 26a are provided with a reference numeral below.

[0057] Each intake unit 26 has a first intake funnel 36a and a second intake funnel 36b for intake of the process gas. Furthermore, as shown, each intake unit 26 has a third intake funnel 36c, a fourth intake funnel 36d, and a fifth intake funnel 36e. The intake funnels 36a-d are arranged on the respective extraction channel 34 of the intake units 26. In other words, the intake funnels 36 of the respective intake unit 26 have a common extraction channel 34.

[0058] As shown, the first suction funnel 36a is arranged, fastened, or formed on the suction channel 34 upstream of the second suction funnel 36b in the (fluidic) suction direction 38. The further suction funnels 36c-e are arranged or formed on the suction channel 34 in a similar manner downstream of the first and second suction funnels 36a, 36b in the suction direction 38. In other words, the suction funnels 36 of a suction unit 26 are arranged one behind the other on the suction channel 34 along a longitudinal channel axis 40. According to the embodiment shown in Fig. 3, the longitudinal channel axis 40 is designed as a straight line. Alternatively, the longitudinal channel axis 40 can be curved. This allows the suction unit 26 to be adapted to an available process space. As shown, the channel longitudinal axis 40 is formed parallel to the suction direction 38.

[0059] According to the illustrated embodiment, each intake funnel 36 has at least two segment walls 42 that delimit the respective intake funnel 36 along the channel's longitudinal axis 40 (for reasons of clarity, only the segment walls 42 of the intake funnel 36a are provided with a reference numeral). The part of the intake unit 26 arranged in the process chamber 14 (see Fig. 2) can thus be divided into segments along the channel's longitudinal axis 40, with each segment comprising an intake funnel 36. The intake funnels 36 are preferably delimited by walls that are orthogonal to the channel's longitudinal axis 40.

[0060] As shown, adjacent intake funnels 36 can have a common segment wall 42. In other words, in this case, adjacent intake funnels 36 adjoin one another. The segment walls 42 can, as shown, be circular segment-shaped or circular ring-shaped. This can ensure a low-loss flow to the intake funnels 36.

[0061] Preferably, each intake funnel 36 has a first funnel wall 44a and a second funnel wall 44b, which delimit the respective intake funnel 36 parallel to the channel's longitudinal axis 40 (for reasons of clarity, only the first and second funnel walls 44a, 44b of the intake funnel 36a are provided with a reference numeral). As shown, the intake funnels 36 can also be delimited by the intake channel 34. Preferably, the intake funnels 36 are designed in the shape of a cylindrical sector, here intake funnel 36a, or in the shape of a hollow cylindrical sector, here intake funnels 36b-e.

[0062] The first funnel wall 44a and the second funnel wall 44b form a funnel angle 46. The funnel angle 46 is preferably between 30° and 270°. This allows for a uniform intake area at the intake funnel 36. According to the illustrated embodiment, the funnel angle 46 is approximately or exactly 90°. This allows for particularly effective use of the available installation space on the coating unit 22.

[0063] The first funnel wall 44a is preferably formed parallel to the working plane 20 (see Fig. 1) of the process chamber 14 (see Fig. 1). This allows the funnel wall 44a to be used to collect excess process powder, which may be located, for example, as a heap on the working plane 20. As shown, the first funnel walls 44a and the second funnel walls 44b of the intake funnels 36a-e can be formed integrally. In other words, all intake funnels 36a-e have the same funnel wall 44a or funnel wall 44b, respectively. This allows the intake funnels 36 to be formed as a structural unit in a particularly cost-effective manner.

[0064] Further, as shown, the funnel walls 44a and 44b may delimit the suction channel 34. In other words, the funnel walls 44a and 44b form a wall of the suction channel 34. This allows the suction unit 26 to be manufactured even more cost-effectively.

[0065] Fig. 4 shows the suction unit 26b from Fig. 3 in a sectional perspective view.

[0066] As shown, the suction channel 34 has a first channel segment 48a and a second channel segment 48b. Furthermore, the suction channel 34 has a third channel segment 48c, a fourth channel segment 48d, and a fifth channel segment 48e.

[0067] The channel segments 48a-e are fluidically connected in series in the suction direction 38. The channel segments 48a-e can, as shown, at least partially overlap along the longitudinal channel axis 40. In other words, the channel segments 48a-e can at least partially protrude into one another. In particular, at least one channel segment 48a-d upstream in the suction direction 38 protrudes into the channel segment 48a-e following next in the suction direction 38 as far as a channel segment 48c-e next next in the suction direction 38. Preferably, several channel segments 48a-d upstream in the suction direction 38 protrude into the channel segment 48b-e following next in the suction direction 38 as far as a channel segment 48c-e next next in the suction direction 38. Alternatively or additionally, a channel segment 48a-e, here channel segment 48c, can extend completely into another channel segment 48a-e, here channel segment 48d.Typically, the channel segments 48a-d upstream in the suction direction 38 have a smaller radial extension relative to the channel longitudinal axis 40 than the channel segments 48b-e downstream in the suction direction 38.

[0068] According to the embodiment of the suction unit 26b shown in Fig. 4, the fifth suction funnel 36e opens into the fifth channel segment 48e in the suction direction 38 via a fifth opening cross-section 50e of the fifth channel segment 48e into the fifth channel segment 48e. Furthermore, the fourth channel segment 48d and the third channel segment 48c open into the fifth channel segment 48e.

[0069] The fourth intake funnel 36d opens into the fourth channel segment 48d in the suction direction 38 via a fourth opening cross-section 50d of the fourth channel segment 48d.

[0070] The third intake funnel 36c opens into the third channel segment 48c in the suction direction 38 via a third opening cross-section 50c of the third channel segment 48c. Furthermore, the second channel segment 48b opens into the third channel segment 48c.

[0071] The second intake funnel 36b opens into the second channel segment 48b in the suction direction 38 via a second opening cross-section 50b of the second channel segment 48b. Furthermore, the first channel segment 48a opens into the second channel segment 48b.

[0072] The first suction funnel 36a opens into the first channel segment 48a in the suction direction 38 via a first opening cross-section 50a of the first channel segment 48a.

[0073] The orifice cross-sections 50a-e typically have the smallest flow cross-sectional area of ​​the respective channel segment 48a-e. In other words, the orifice cross-section 50a-e limits the volume flow of process gas that can be extracted through the respective channel segment 48a-e. Preferably, the flow cross-sectional area of ​​the orifice cross-sections 50a-e decreases, in particular continuously, in the extraction direction. As a result, the volume flow of process gas for the intake funnels 36 drawn in via the intake funnels 36 can be kept constant, regardless of a pressure loss in the extraction channel 34.

[0074] In contrast, a radial extension of the suction channel 34 in the suction direction 38 preferably increases, whereby unnecessary pressure losses as a result of a larger cumulative volume flow through the individual suction funnels 36 are avoided.

[0075] The channel segments 48a-e can form a circular sector-like or annular sector-like channel segment cross-section. Preferably, the outlet cross-sections 50a-e are circular segment-like, here outlet cross-section 50a, or annular segment-like, here outlet cross-sections 50b-e.

[0076] As shown, a channel segment 48a-e, into which a specific intake funnel 36a-e opens, can define the wall of the intake funnel 36b-e following in the suction direction 38. For example, the first channel segment 48a forms a wall of the second intake funnel 36b.

[0077] List of reference symbols

[0078] Additive manufacturing device 10;

[0079] Suction device 12;

[0080] Trial Chamber 14;

[0081] Process gas supply unit 16;

[0082] Working cylinder 18;

[0083] Working level 20;

[0084] Coating unit 22;

[0085] Movement axis 24;

[0086] Intake unit 26, 26a, 26b;

[0087] Main flow path 28;

[0088] secondary flow path 30;

[0089] Process chamber wall 32;

[0090] Suction channel 34;

[0091] Intake funnel 36, 36a-e;

[0092] Suction direction 38;

[0093] Channel longitudinal axis 40;

[0094] Segment wall 42;

[0095] funnel wall 44a, b;

[0096] funnel angle 46;

[0097] Canal segment 48a-e;

[0098] Muzzle cross-section 50a-e.

Claims

Patent claims Suction unit (26; 26a, 26b) for a suction device (12) for sucking a process gas from a process chamber (14) of an additive manufacturing device (10), comprising - a first suction funnel (36a) and a second suction funnel (36b) for sucking in the process gas within the process chamber (14); - an extraction channel (34) for discharging the process gases sucked in through the intake funnels (36; 36a-e); wherein the first intake funnel (36a) is arranged or formed on the extraction channel (34) upstream of the second intake funnel (36b) in an extraction direction (38); wherein the extraction channel (34) has a first channel segment (48a) with a first opening cross-section (50a) and a second channel segment (48b) with a second opening cross-section (50b); wherein the first opening cross-section (50a) has a flow cross-sectional area that is larger than a flow cross-sectional area of ​​the second opening cross-section (50b); and wherein the first intake funnel (36a) opens into the first channel segment (48a) and the second intake funnel (36b) and the first channel segment (48a) open into the second channel segment (48b).Suction unit (26; 26a, 26b) according to claim 1, comprising at least one further channel segment (48c-e) and at least one further suction funnel (36c-e), wherein the further channel segment (48c-e) is arranged or formed on the suction channel (34) behind the first channel segment (48a) and the second channel segment (48b) in the suction direction (38); wherein the further suction funnel (36c-e) and the The channel segment (48b-d) located upstream of the further channel segment (48c-e) in the suction direction (38) opens into the further channel segment (48c-e). The suction unit (26; 26a, 26b) according to claim 1 or 2, wherein the first channel segment (48a) extends into the second channel segment (48b). The suction unit (26; 26a, 26b) according to claim 3, wherein several, in particular all, channel segments (48a-e) extend into the channel segment (48b-e) following the respective channel segment (48a-e) in the suction direction (38). The suction unit (26; 26a, 26b) according to one of the preceding claims, wherein the opening cross-sections (50a-e) in the suction direction (38) of the suction channel (34) have a decreasing flow cross-sectional area. Intake unit (26; 26a, 26b) according to one of the preceding claims, wherein at least one mouth cross-section (50a-e) is designed as a circular sector or as a circular ring sector.Intake unit (26; 26a, 26b) according to one of the preceding claims, wherein the first channel segment (48a) delimits the second intake funnel (36b). Intake unit (26; 26a, 26b) according to one of the preceding claims, wherein the intake funnels (36a-e) are each delimited along a channel longitudinal axis (40) by two segment walls (42), wherein the segment walls (42) are formed in particular orthogonal to the channel longitudinal axis (40). Intake unit (26; 26a, 26b) according to claim 8, wherein the. Segment walls (42) are formed in the shape of a circular sector or annular sector. The intake unit (26; 26a, 26b) according to one of the preceding claims, wherein the intake funnels (36a-e) each have a first funnel wall (44a) and a second funnel wall (44b), wherein the funnel walls (44a, b) form a funnel angle (46). Intake unit (26; 26a, 26b) according to claim 10, wherein the funnel angle (46) is between 30° and 270°, preferably between 45° and 135°, particularly preferably between 80° and 100°. Intake unit (26; 26a, 26b) according to claim 10 or 11, wherein the at least two intake funnels (36a-e) have common funnel walls (44a, b). Intake unit (26; 26a, 26b) according to one of the preceding claims, wherein the first and / or the second intake funnel (36a, b), in particular all intake funnels (36a-e), are designed in the shape of a cylinder sector or a hollow cylinder sector. Intake unit (26; 26a, 26b) according to one of the preceding claims, wherein at least two intake funnels (36a-e) have the same extension along the channel longitudinal axis (40).Additive manufacturing device (10) with a suction device (12) for sucking process gases out of a process chamber (14) of the additive manufacturing device (10), comprising at least one suction unit (26; 26a, 26b) according to one of the preceding claims arranged on the suction device (12). Additive manufacturing device (10) according to claim 15, comprising a coating unit (22) for distributing process powder in a working plane (20) of the additive manufacturing device (10), wherein the at least one suction unit (26; 26a, 26b) is arranged or formed on the coating unit (22) and is designed to follow a movement along a movement axis (24) of the coating unit (22).Additive manufacturing device (10) according to claim 16, comprising at least two suction units (26; 26a, 26b) according to one of claims 1 to 14, wherein a first suction unit (26a) is arranged or formed upstream of the coating unit (22) along the movement axis (24) of the coating unit (22) and a second suction unit (26b) is arranged or formed downstream of the coating unit (22) along the movement axis (24) of the coating unit (22). Additive manufacturing device (10) according to one of claims 16 or 17 in conjunction with a suction unit (26; 26a, b) according to one of claims 10 to 12, wherein a funnel wall (44a, b) of at least one suction funnel (36a-e) is formed parallel to the working plane (20) of the additive manufacturing device (10).

Images