Cooling module for use in an additive manufacturing process and manufacturing system comprising a cooling module

Abstract

A cooling module (10) for use in an additive manufacturing process, comprising a housing (12), a transport device, and a cooling medium drive unit (40), wherein the housing (12) has at least one first opening region (26) for admitting a cooling medium by means of the cooling medium drive unit (40), and the transport device is designed to convey a manufactured article (32) with excess manufacturing material from a manufacturing location of the article (32) into the housing (12) of the cooling module (10), wherein a feed rate of the transport device is adjustable as a function of a volume flow of the cooling medium controlled by the cooling medium drive unit (40), so that an accelerated cooling process of the manufactured article (32) with excess manufacturing material can be carried out.the housing (12) has at least one second opening region (28) for sucking out the cooling medium and / or the excess production material by means of a first suction unit (44), characterized in that the at least one second opening region (28) is provided in front of the at least one first opening region (26) in the direction of movement of the transport device, wherein the at least one second opening region (28) is arranged in an upper region (14) of the housing (12) and the at least one first opening region (26) is arranged in a lower region (18) of the housing (12).

Description

The invention relates to a cooling module for use in an additive manufacturing method and to a manufacturing installation comprising a corresponding cooling module.Additive manufacturing processes are increasingly being considered an established technique in industrial production. In this case, various types of method are already to be considered known, which make it possible to produce three-dimensional objects from shapeless or shape-neutral materials on the basis of previously created design data. The materials used for this purpose may, for example, be present beforehand in powder form. In addition to the general term additive manufacturing method, further terms are also used to ultimately produce an object by means of a layer-by-layer application of a starting material. In addition to the term 3D printing, such methods are also referred to as generative production or production methods by means of rapid technologies. Depending on the basic alignment of the method used, variants with completely molten starting materials, but also variants with only partly molten additives, are to be regarded as already known. In this connection, the use of different laser technologies is widely used and increasingly represents a standard for the industrial application. In order to further increase the productivity of all processes, increasingly continuous process concepts are in the focus of technical development. In this case, the articles to be produced are intended to pass through the intended production steps in an automated manner, wherein a respective transport to the individual processing stations is carried out precisely continuously by means of correspondingly automated transport devices.In the development of a continuous 3D printer in the inclined bed method, for example by means of the use of selective laser sintering technology, selective laser melting technology or another powder bed-based method (for example the MJF method=multijet fusion method), the component to be produced is first produced in a first production region. Subsequently, this component is removed in a second region after a cooling process. Between these two aforementioned areas, a cooling zone is provided. This cooling zone is matched to a respective component size and can have lengths of between 0.1 and 30 meters, for example. For example, if the component to be manufactured is a bumper of a motor vehicle, such a cooling zone may be several metres long. Installations with such a length usually involve a high conveying outlay. It is also true to maintain a high accuracy throughout the production line, wherein a corresponding outlay has to be used, in particular in the case of longer cooling sections. In addition, such long cooling zones require a larger amount of operating material, which is provided, for example, in the form of powder material. In this respect, the previous concepts are associated with a certain cost and thus inhibit this technology for a wide application in industry at this point.In the future, the additive manufacturing methods will be further improved for use in industrial mass production, so that in the course of this technical development further objectives or more cost-effective alternatives to previous approaches are required. First approaches can already be taken as known from the prior art, as is illustrated below with reference to some examples.The publication DE 10 2017 211 381 A1 discloses a method for cooling and a cooling device as known. In particular, the method for cooling a three-dimensional object by treatment with a fluid medium is provided, wherein the object is produced by layer-by-layer selective solidification of a powdered construction material and unsolidified construction material in which the object is embedded. The fluid medium is formed from a carrier gas which is selectively enriched with an additional component comprising a further gas and / or a liquid, and / or from a gas mixture which is selectively at least partially removed from at least one mixture component.Furthermore, the publication US 2004 / 0084814 A1 discloses a powder removal system for a three-dimensional object manufacturer. In particular, a three-dimensional object manufacturer with a system for removing unbound powder is disclosed. The object manufacturer forms an object by binding areas of unbound powder in a chamber to which the unbound powder removal system is operatively attached. Unbound powder is removed from the chamber by the unbound powder removal system.From document WO 2017 / 194144 A1 a container for 3D printed objects and a method for cooling and unpacking a manufactured object from a 3D printer using this container can be seen as known. Here, the container for accommodating the manufactured object is provided by the 3D printer, and the method is provided for cooling and unpackaging the 3D printed objects with this container. The container has a wall forming the sides of the container, a top extending to the sides of the container, a connector for connection to a vacuum source, and a guillotine member. The lower portion of the container includes support members for slidably receiving the guillotine member to form a base of the container. The guillotine member is optionally configurable between an apertured configuration having a plurality of through-holes to allow passage of air and / or build material and a closed configuration in which the through-holes are closed to prevent build material from dropping out of the container.EP 1 192 040 B1 discloses a method and an apparatus for producing a three-dimensional object by means of an additive manufacturing method. It is provided that unsolidified powder surrounding the object and the object is moved in a housing. A stream of air is injected into the housing transversely to the direction of movement in order to remove superfluous material and simultaneously cool the object.The object of the invention is to provide an alternative cooling module for use in an additive manufacturing method, with which an accelerated and cost-effective cooling process can be ensured.It is contemplated that a cooling module is provided for use in an additive manufacturing process. Such a cooling module comprises a housing, a transport device and a cooling medium drive unit, wherein the housing has at least one first opening region for the admission of a cooling medium by means of the cooling medium drive unit. The transport device is further configured to transport a manufactured article with excess manufacturing material from a manufacturing location of the article into the housing of the cooling module. In this case, a feed speed of the transport device can be adjusted as a function of a volume flow of the cooling medium controlled by means of the cooling medium drive unit, so that an accelerated cooling process of the manufactured object can be carried out with excess manufacturing material. In this way, an object produced by means of an additive manufacturing method can be cooled particularly quickly and economically after production. The module can be arranged or positioned accordingly to a manufacturing location at which the object is produced, so that the transport device can transport the manufactured object with possibly excess manufacturing material from the manufacturing location into the housing of the module. For example, the transport device can comprise at least one conveyor belt for this purpose, on which the object can then be moved away from the production site into the housing. In this respect, a direction of movement from the manufacturing location into the module is thus provided.The transport device has a feed speed in the direction of movement which can be adjusted as a function of a volume flow of the cooling medium regulated by means of the cooling medium drive unit. In other words, a certain volume flow causes at least one adjustment value of the feed speed, so that an accelerated cooling process of the manufactured object can be carried out with excess manufacturing material. It is also conceivable that a speed profile of this feed speed that is set is caused accordingly by a dynamically changing volume flow. For this purpose, the cooling medium drive unit and the transport device can be coupled directly, for example, or can be controlled accordingly via a superordinate control unit. The module presented thus enables a generally running production method of a respective additive manufacturing method. For example, such an additive manufacturing method can be an SLSbeziehungsweise SLM method, wherein in each case, for example, a tilted bed method can be provided. The transport device thus conveys the produced or printed object into a region in which the cooling effect of the volume flow of the cooling medium acts on the object, such that a user-defined cooling process can be ensured particularly efficiently and uniformly.In particular, with the module presented, in the case of a transport device which is set particularly well, cooling and removal of the manufactured object or of the component which is printed in a complex manner can be achieved in one process step as a function of the volume flow, with the result that, overall, further costs can thus be saved. The module presented makes possible an overall shortened manufacturing plant on account of the particularly efficient cooling process and additionally ensures reliable process management.Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.The housing has at least one second opening region for suctioning the cooling medium and / or the excess manufacturing material by means of a first suctioning unit. In this way, the cooling process can be further accelerated since the cooling medium heating during the process is sucked off again immediately, so that new cooling medium can be tracked correspondingly quickly. In addition, excess production material which was not used for the actual production of the object can also be suctioned off, so that the at least partially exposed object can then be cooled even more quickly. In this respect, an air flow can be set with the module presented in such a way that it can be provided for the coupled removal of the powder and the warm air. The air flow is set particularly efficiently in this case, since the feed speed of the transport device is provided as a function of the volume flow.According to the invention, it is provided that the at least one second opening region is provided before the at least one first opening region in the direction of movement of the transport device, wherein the at least one second opening region is arranged in an upper region of the housing and the at least one first opening region is arranged in a lower region of the housing. The direction of movement of the transport device is thus provided from the manufacturing location at which the object was manufactured in the direction of the module and in particular provided such that the object is moved forward into the housing coming from the manufacturing location. The object can also be conveyed beyond the housing. The transport device can comprise, for example, at least one conveyor belt, wherein the corresponding direction of movement of such a conveyor belt is provided from a manufacturing location arranged in front of the module on one side into the housing and possibly even beyond this housing. In this way, a flowing process method can be promoted and the movement of the object and of the excess production material by means of the transport device can be incorporated into a cooling process by means of the module presented. Depending on the volume flow set, a feed speed can be set automatically, so that an optimum and particularly rapid cooling process is ensured.Because the cooling medium is introduced from a lower region and is suctioned off in an upper region, a particularly effective flow can be established, so that an accelerated cooling process can be achieved cost-effectively. In this way, for example, a slanting position of the excess manufacturing material, which can be present, for example, in powder form, can be established, so that a type of convection position of the air flow can be established, which can thus absorb and transport away the excess heat in a particularly effective manner.In other words, the air flow which is established removes the warm air and reproduces cold cooling medium. In this respect, an intended supply of the cooling medium at the bottom and a suction at the top promote a thermal effect, so that in combination with the forward movement a particularly efficient cooling process is made possible. In addition, this air flow can carry away excess production material, for example in powder particle form, and thus enable subsequent removal of the produced object from the excess production material. For example, the module can be used in a method in which the manufactured object or the component is located in a powder bed during and after the manufacturing.In addition, in a further embodiment of the invention, it is provided that the at least one second opening region is arranged in a ceiling region of the housing and the at least one first opening region is arranged in a floor region of the housing. The aforementioned advantages can thus be achieved even better.Furthermore, in a further embodiment of the invention, it is provided that the at least one second opening region is arranged in an upper side region of the housing and the at least one first opening region is arranged in a lower side region of the housing. The flow that occurs can thus be adjusted particularly efficiently, for example depending on the inflow angle of the cooling medium according to the geometry of the manufactured object. In this case, the incoming cooling medium impinges from an opposite inner side of the housing and is thus directed particularly well over the region to be cooled.In a further embodiment of the invention, it is also provided that the at least one second opening region is arranged in a first upper side region of the housing and the at least one first opening region is arranged in a second lower side region of the housing, wherein the second side region of the housing is provided opposite the first side region. The flow that occurs can thus be set particularly efficiently, for example depending on the inflow angle of the cooling medium according to the geometry of the manufactured object. In this case, the incoming cooling medium impinges from an opposite inner side of the housing and is thus directed particularly well over the region to be cooled.This effect is particularly promoted and additionally even more enhanced by the position of the respective first and second opening regions. It is conceivable that the feed speed of the transport device is thus adjustable not only as a function of the volume flow per se, but also as a function of the air flow that is established and the flow directions associated therewith, so that a particularly efficient cooling process can be achieved. In this context or generally, a respective geometry of the component to be produced and a cooling requirement associated therewith can also determine the feed speed.In addition, in a further embodiment of the invention, it is provided that the at least one second opening region is arranged in front of the at least one first opening region with respect to the direction of movement of the transport device and a distance between the at least one second opening region and the at least one first opening region can be adjusted in a user-defined manner. For example, the opening areas can essentially have the shape of longitudinal holes in the housing, wherein an opening size can be varied by means of a closing element, so that a specific and intentionally desired distance results. A flow of the cooling medium that is established can thus be additionally designed, so that an even more efficient and thus more cost-effective cooling process can be provided.Furthermore, in a further embodiment of the invention, it is provided that the cooling medium is provided at least partially from an air-gas mixture and is preferably provided temperature-controlled in a temperature interval which is matched to the materials used, in particular is provided temperature-controlled in a temperature interval of 5 to 35° C. for plastics. The aforementioned advantages can thus be achieved even better.Finally, in a further embodiment of the invention, it is provided that, with respect to the direction of movement of the transport device, behind the at least one first opening region in the base region of the housing, at least one third opening region is provided in the housing, such that excess manufacturing material can be disposed of by means of the influence of gravity and / or due to an attached second suction unit. It can thus be ensured that the last excess manufacturing material is also removed almost completely from the housing, so that the cooled component or the manufactured object can be removed directly from the housing subsequently.In a further preferred embodiment of the invention, it is provided that a production plant is provided for use in an additive production method. Such a manufacturing system comprises at least one cooling module according to claims 1 to 7.The various embodiments of the invention mentioned in this application can be combined with one another with advantage unless stated otherwise in the individual case.The invention is explained below in exemplary embodiments with reference to the associated drawings. The following are shown: FIG. 1 shows a schematic sectional view of a cooling module for use in an additive manufacturing method; FIG. 2 shows a schematic illustration of a production plant for use in an additive production method with a cooling module.FIG. 1 shows a schematic sectional view of a cooling module 10 for use in an additive manufacturing method. The cooling module 10 is shown here with a housing 12. The housing 12 is shown here on the left and right with respect to the plane of the drawing in a cut-away manner, so that these respective end regions are not shown in more detail. In an upper region 14 of the housing 12, a ceiling region 16 of the housing 12 is provided. In a lower region 18 of the housing 12, a base region 20 of the housing 12 is provided. The ceiling region 16 has a ceiling 22 of the housing 12 and the floor region 20 has a floor 24. In the base region, a first opening region 26 is provided, which in this case is illustrated as a through opening in the base 24 of the housing 12. In the ceiling region 16, a second opening region 28 is provided, which in this case is illustrated as a through opening in the ceiling 22 of the housing 12. Between the ceiling region 16 and the floor region 20 or between the ceiling 22 and the floor 24, an interior 30 of the housing 12 is shown, in which an object 32 produced by means of an additive manufacturing method is shown. The object 32 is a component of a vehicle, in particular of a motor vehicle. In particular, the component is a front fascia of a motor vehicle. The object 32 projects on the right side (with respect to the image plane) from a powder bed 34. The powder bed 34, which substantially comprises excess manufacturing material, fills the interior 30 of the left-hand side of the housing 12 shown in section, wherein it correspondingly runs out to the right with a pouring angle 36 from the ceiling 22 to the floor 24.In other words, the powder bed 34 is shown falling to the right along a pouring plane 38, so that the object 32 partially protrudes substantially centrally out of the powder bed 34. The angle of gravity 36 is thus provided between the plane of gravity 38 and the bottom 24 and is approximately 30° in the figure shown. The pouring plane 38 extends from left to right (in relation to the drawing plane) from the ceiling 22 in the ceiling region 16 in front of the second opening region 28 to the floor 24 in the floor region 20 in front of the first opening region 26. This cooling medium drive unit 40 can project into the interior 30 and can comprise, for example, at least one ventilation element or a ventilation device, so that a cooling medium, not shown in more detail, can be blown or conveyed into the interior 30. The cooling medium can be, for example, an air-gas mixture which is cooled to a user-defined temperature in the cooling medium drive unit 40 itself or in an additional cooling device, not shown in detail, so that after blowing into the interior 30, it cools the powder bed 34 and the object 32 accordingly.During this cooling process, the cooling medium provided heats up and rises in the process in the form of convection movements 42. These convection movements 42 form along the pouring plane 38. At the upper left end of the pouring plane 38, a suction unit 44 is shown in a greatly simplified manner in the second opening region 28. This suction unit 44 can comprise, for example, a suction pump or another vacuum pump. The warmed cooling medium can be suctioned off via the suction unit 44. In addition, depending on the intensity of the suction flow, the excess production material in the powder bed 34 can also be at least partially suctioned off via the suction unit 44. The powder bed 34 and the object 32 located therein can be moved from left to right (with respect to the image plane) by means of a transport device, not shown in more detail. This transport device, which is not shown in more detail, can comprise, for example, at least one conveyor belt and be designed to transport the powder bed 34 with the object 32 from a production location, which is not shown in more detail, into the housing 12 or the interior 30 of the housing 12. A feed speed of the transport device can be adjustable as a function of a volume flow of the cooling medium regulated by means of the cooling medium drive unit 40, so that an accelerated cooling process of the manufactured object 32 can be carried out with excess manufacturing material. For example, in this context, the transport device, not shown in more detail, can be coupled directly and / or via a control unit, likewise not shown in more detail, to the cooling medium drive unit 40. It can also be provided that at least partially a user-defined setting of the two units is carried out, wherein a respective setting value depends on the others. A directional arrow 46 in FIG. 1 indicates to what extent a direction of movement is provided by the transport device, not shown in more detail, with respect to the image plane.Also shown is a distance 48 between the second opening portion 28 and the first opening portion 26. The excess production material, for example in powder form, could also be removed downwardly from the interior 30 of the housing 12 via third opening regions, which are not shown in detail and which could be provided behind the first opening region 26 with respect to the plane of the drawing, according to the gravitational principle and / or by means of a further suction unit, which is likewise not shown in detail. The part of the object 32 which is still entirely located in the powder bed 34 still has a relatively high temperature.In FIG. 1, this state is schematically represented by a corresponding temperature field display 49. The temperature field display 49 is only shown pictorially above the object 32 for purposes of illustration and thus demonstrates ranges in which higher temperature values can be measured in contrast to the environment. With the cooling module 10 shown, a cooling of the object 32 and a removal of the excess manufacturing material from bottom to top (with respect to the image plane) can thus result. The dependence of the set feed speed of the transport device and the corresponding volume flow of the cooling medium enable the desired effect, wherein the arrangement of the opening regions 26, 28 additionally promotes this effect in a supporting manner.FIG. 2 shows a schematic illustration of a production plant 50 for use in an additive production method with a cooling module 10, wherein a production site 52 is illustrated in relation to the image plane upstream of the cooling module 10. This production site 52 can be, for example, the printing region of an additive production method in which a component, not shown in more detail, is printed. In this respect, the production site 52 can comprise not only a housing but also a 3D printing device provided there.For example, the production site 52 could comprise any means which are required to provide an SLS / SLM method in the tilted bed method, with which it is then possible to print components accordingly in series one after the other with a relatively high number of cycles. The greatly simplified production plant 50 is thus provided for a type of serial conveyor line production of printed components. Subsequently, this manufactured component can be conveyed further in the direction of the cooling module 10 via a transport device, likewise not shown in detail. In this case, it can be transported away, for example, together with excess production material.In a variant not shown in more detail, a holding zone can additionally be provided between the production site 52 and the cooling module 10, which holding zone can be provided, for example, as a buffer for further manufactured articles. The cooling module 10 can be designed in such a way that subsequent removal of the component is also possible.List of reference characters10 Cooling module 12 Housing 14 Upper region 16 Ceiling region 18 Lower region 20 Floor region 22 Ceiling 24 Floor 26 First opening region 28 Second opening region 30 Interior space 32 Object 34 Powder bed 36 Angle of gravity 38 Fill plane 40 Cooling medium drive unit 42 Convection movement 44 Suction unit 46 Directional arrow 48 Distance 49 Temperature field display 50 Production plant 52 Production site

Claims

Cooling module (10) for use in an additive manufacturing method comprising a housing (12), a transport device and a cooling medium drive unit (40), wherein the housing (12) has at least one first opening region (26) for introducing a cooling medium by means of the cooling medium drive unit (40), and the transport device is designed to transport a manufactured article (32) with excess manufacturing material from a manufacturing location of the article (32) into the housing (12) of the cooling module (10), wherein a feed speed of the transport device can be adjusted as a function of a volume flow of the cooling medium controlled by means of the cooling medium drive unit (40), such that an accelerated cooling process of the manufactured article (32) with excess manufacturing material can be carried out, the housing (12) has at least one second opening region (28) for suctioning the cooling medium and / or the excess manufacturing material by means of a first suctioning unit (44), characterized in that the at least one second opening region (28) is provided in front of the at least one first opening region (26) in the direction of movement of the transport device, wherein the at least one second opening region (28) is arranged in an upper region (14) of the housing (12) and the at least one first opening region (26) is arranged in a lower region (18) of the housing (12).Cooling module (10) according to Claim 1, wherein the at least one second opening region (28) is arranged in a ceiling region (16) of the housing (12), and the at least one first opening region (26) is arranged in a floor region (20) of the housing (12).The cooling module (10) of claim 1, wherein the at least one second opening portion (28) is disposed in an upper side portion of the housing (12) and the at least one first opening portion (26) is disposed in a lower side portion of the housing (12).The cooling module (10) according to claim 3, wherein the at least one second opening portion (28) is disposed in a first upper side portion of the housing (12) and the at least one first opening portion (26) is disposed in a second lower side portion of the housing (12), the second side portion of the housing (12) being provided opposite the first side portion.Cooling module (10) according to one of the preceding claims, wherein the at least one second opening region (28) is arranged in front of the at least one first opening region (26) with respect to the direction of movement of the transport device and a distance between the at least one second opening region (28) and the at least one first opening region (26) is adjustable in a user-defined manner.Cooling module (10) according to one of the preceding claims, wherein the cooling medium is provided at least partially from an air-gas mixture and is preferably provided temperature-controlled in a temperature interval which is matched to the materials used, in particular is provided temperature-controlled in a temperature interval of 5 to 35°C for plastics.Cooling module (10) according to one of the preceding claims, wherein, with respect to the direction of movement of the transport device, behind the at least one first opening region (26) in the base region (20) of the housing (12), at least one third opening region is provided in the housing (12), such that excess manufacturing material can be disposed of by means of the influence of gravity and / or on account of a second suction unit being applied.Manufacturing plant for use in an additive manufacturing method comprising at least one cooling module (10) according to claims 1 to 7.

Images