Additive processing apparatus and additive processing method having a separated process chamber

Abstract

The present invention relates to a manufacturing plant based on optical interactions, in particular a manufacturing plant for selective laser melting. By a special arrangement of the main components of the device, such as the process chamber 1 and the optical module 9, relative to each other, and by providing separate bearings and positioning elements, particularly high precision in component manufacturing can be achieved in a simple manner.

Description

Technical Field

[0001] The present invention relates to a manufacturing plant that can be automated and is based on optical interactions, in particular to a manufacturing plant for selective laser melting (SLM) having an optimized arrangement of precision-determining components so as to minimize external interference and interference occurring during the process. In addition, an optimized post-processing method is proposed.

Background Art

[0002] In SLM systems known in the prior art, the individual elements necessary for manufacturing SLM components such as optical modules, build chambers, coaters, and Z-axes are constructed such that they are directly attached to the build chamber or directly attached to each other.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, this type of connection has the drawback that undesirable changes occur in the overall structure when the relative position and / or orientation of the elements or sub-components within this composite material change, particularly due to the effects of thermal deformation or forces. This results in deviations and inaccuracies in the manufacture of the components to be manufactured. Deformation of the structure of the main components usually causes point positioning errors in the position and orientation of the laser beam within the powder plane, which cannot be reproduced and compensated, or can only be compensated at very high cost.

[0004] Specifically, in the case of an SLM machine having a plurality of laser scanner systems, there may also be deviations in the relative positions of the various laser beams within the powder plane. In addition, deviations in the powder bed surface such as position or orientation and the actual layer thickness may occur. Therefore, the quality of the components to be manufactured is affected, and geometric defects such as shape and position deviations, deterioration of surface quality, or metallurgical defects such as bonding defects or gas porosity may occur.

[0005] An apparatus for manufacturing a shaped body based on the principle of selective laser melting is known, for example, from German Patent Application Publication No. 102019200680A1. The subject matter of this application is incorporated herein by reference.

Means for Solving the Problems

[0006] One object of the present invention is to provide a manufacturing apparatus for additional processing that can achieve improved manufacturing quality of the manufactured components. In addition, an object of the present invention is to provide an optimized manufacturing process that can achieve improved manufacturing quality. Specifically, an object of the present invention is to minimize the interfering factors and interfering effects that occur during the manufacturing of SLM components, particularly the thermal effects and the effects of forces, and as a result, improve the quality of the manufactured object.

[0007] For melting the object, the functions of the independent claims are proposed. Advantageous embodiments can be found in the dependent claims.

[0008] An apparatus for layer-by-layer deposition of an object of powder material by optical interaction may include a process chamber and at least one optical module. Specifically, the apparatus can utilize a selective laser melting process.

[0009] The process chamber can be provided to offer a working space in the construction yard. It is possible to provide at least one optical module which is part of the irradiation unit or forms an irradiation unit for spatially selectively irradiating the material present in the area of the construction yard. Preferably, the optical module is arranged above the process chamber and spaced apart from the process chamber. The primary carrier or receiving element can be used to enable the central connection of the individual main components of the device. The receiving element or basic element functions as a carrier unit for receiving or supporting the main components of the device or manufacturing plant. The main components particularly include the components of the device required for manufacturing an object, namely, in particular one or more optical modules, the process chamber, the coater, and the Z-axis, and / or the lifting device. Advantageously, at least one optical module is attached to or received by the basic element at a first joint. More advantageously, the process chamber is received by or attached to the basic element at a separate second joint separated from at least one optical module. Thus, the optical module is arranged separately from the process chamber, whereby the optical module as well as the process chamber are each attached to the basic element.

[0010] Thus, the thermal expansion of the process chamber no longer directly affects the separated optical module. Since all the main components of the device are preferably provided separately and spaced apart from each other on the basic element, the thermal or mechanical influence of the main components on each other is also minimized.

[0011] Preferably, the main components are only accommodated on the basic element, and particularly preferably, the main components are each supported only at one or more joints provided separately for each of the main components. Thus, the main components or accuracy-determining components are arranged so as not to affect each other or to keep the influence to a minimum.

[0012] Particularly preferably, the process chamber is attached to the base member via a plurality of joints, each of the joints being spaced apart from the first joint (to which the optical module is attached), and particularly preferably, the plurality of joints are arranged substantially in a horizontal plane.

[0013] Particularly preferably, the basic element has a reference plane with respect to which the main components are arranged and positioned, and for example, the relative position thereof is used as position information to compensate for deformation.

[0014] In other words, all relevant components are preferably attached to the basic element and defined as a common reference plane, and particularly preferably, the plane of the device, which is the reference plane of the optical module, is used as the reference plane for each of the individual main components.

[0015] This characteristic arrangement of the main components, in particular the optical module and the process chamber, which are directly separated from each other on the basic element, can significantly improve the manufacturing quality of the device so as to minimize the thermal and mechanical effects of these components.

[0016] Individual major components of devices such as a process chamber, an optical module, a lifting device, and a construction cylinder can be attached to each other separately, preferably directly to the basic elements. Preferably, the attachment is designed to allow thermal expansion of the individual components without introducing significant forces into the basic elements, so that as a result, deformation of the major components is freely possible within a predetermined tolerance range without introducing forces or deformations into other major components or basic elements. For example, the support points of the major components can be reduced for this purpose, so that as a result, they are each attached only to their own support points on the basic element, for example, and as a result, the body of the tethered major component does not introduce forces into the basic element or only minimal forces in the case of thermal deformation. In addition, it is possible to design the support points of the major components housed in such a way that in particular a clearance is provided in the vertical direction so that no force is introduced into the basic element in the case of vertical thermal expansion of the tethered major components. Specifically, by arranging the individual major components separately on the same basic element, the mutual thermal and mechanical influences of the major components can be minimized, and as a result, the quality of the manufactured components can be improved.

[0017] At least one of the main components, such as a process chamber, an optical module, a lifting device, and / or a construction cylinder, can be attached to the basic element in a thermally isolated manner. The thermally isolated attachment on the basic element can be achieved, for example, by using components made of heat-insulating materials. Specifically, for example, heat-insulating plates and heat-insulating disks made of ceramic or glass or fiber-reinforced plastics can be used as intermediate elements at the support points or joints. In addition, spacer plates made of heat-insulating plastics can be used. With this advantageous embodiment, the thermal influence on the basic element can be further reduced. As a result, the influence of the main components on each other can also be significantly reduced. Specifically, the thermal deformation of the process chamber is inevitable, and as a result, at least the process chamber is preferably attached via a heat-insulating material such as a ceramic plate or a plastic disk to at least one support point or joint (preferably each).

[0018] The cooling device may be provided at a second joint to cool the joint. The second joint is a (one or more) joint of the process chamber with the basic element, separate from the first joint. For example, the cooling channels may be provided in a bearing plate or a support plate, thereby enabling active cooling or temperature control of the second joint (or second joints), thereby minimizing or actively influencing the thermal impact of the process chamber on the basic element and other main components. Passive cooling is also possible, and as a result, for example, cooling fins can be provided to cool the second joint (or second joints), thus contributing to reducing the thermal influence of the process chamber on the basic element.

[0019] Preferably, the main components of the device can be thermally and mechanically separated from the process chamber. Specifically, the main components of the device can be provided separately from the process chamber on the basic element. Specifically, one or more adapter elements can also be provided between the optical module and the process chamber to shield it from the environment in an airtight and / or laser-safe manner. The adapter element is preferably arranged above the process chamber and below the optical module. The adapter element is provided as an intermediate element between the optical module and the process chamber, and the adapter element can be designed particularly flexibly, enabling an airtight shield of the transmission area from the optical module to the process chamber, so that a flexible connection can be realized and the optical module can be thermally and mechanically separated from the process chamber. Preferably, the adapter element is directly connected to the optical module and directly connected to the process chamber. Therefore, even if the process chamber is strongly heated, it will not affect the optical module. Advantageously, the adapter element is connected to the process chamber such that relative movement between the process chamber and the adapter element is permitted in both the horizontal and vertical planes. For this purpose, a sealing ring and / or a membrane can be provided at the connection. By using a displaceable bearing (preferably in the horizontal and vertical directions) combined with the sealing ring and / or the membrane, the relative movement of the connected process chamber can be released. Therefore, the deformation of the process chamber is not transmitted to the optical module via the adapter element, but is compensated in an airtight and / or laser-safe manner by a specific connection of the adapter element. The mutual thermal and mechanical influence of the components can be minimized, and as a result, the manufacturing quality of the components can be significantly improved.

[0020] A flexible design of the adapter element is particularly advantageous, as a result of which a relative movement of the process chamber with respect to the optical module without mechanical stress can be achieved. For this purpose, the adapter element can, for example, have a telescopic structure and / or can be made of a flexible material. Specifically, the adapter element comprises at least one membrane and / or at least one sealing ring in order to enable mechanical and thermal separation from the process chamber and / or the optical module.

[0021] Particularly preferably, the adapter element has an integral protective glass in order to protect the optical module from the process atmosphere of the process chamber contaminated with particles. Particularly preferably, the protective glass is firmly connected to the optical module in order to prevent relative displacement of the protective glass with respect to the optical module, thereby ensuring the accuracy in the manufacture of the components. Particularly preferably, the adapter element is provided between the optical module and the process chamber and communicates with the optical module and the process chamber.

[0022] The individual main components can have a common reference plane. The individual main components can be aligned with each other via the common reference plane, in particular by positioning elements made of a temperature-invariant material. The temperature-invariant material is, for example, Invar or a fiber-reinforced plastic such as carbon fiber-reinforced plastic or glass fiber-reinforced plastic. For example, ceramics or glass can also be used. Due to the fact that all individual main components have a common reference plane, the determination of the position, displacement, and orientation of the main components can be carried out with respect to the common reference plane, as a result of which the determination of the position and orientation of the main components becomes accurately possible, for example, via machine control and thus by adjusting the beam path, the displacement with respect to the reference plane can be compensated. In order to enable the position and orientation of the main components to be determined as accurately as possible, the relative position of the individual main components with respect to the common reference plane can also be carried out with respect to the positioning elements provided for each main component. The positioning elements are made of a temperature-invariant material and since they are directly connected to the common reference plane, the positioning elements act essentially temperature-invariantly. As a result, the individual positioning elements provide a reference point or reference scale for the metrological determination of the position and orientation of the individual main components. Thus, the displacement or orientation of the main components can be determined in a simple and reliable manner by determining the relative position and orientation with respect to the positioning elements. Preferably, the positioning elements extend vertically downward from the common reference plane at the top of the basic element into the device, extend into the process chamber, and extend into the lifting device and / or the construction cylinder.

[0023] At least one of the main components can advantageously be coupled to a common reference plane by positioning elements in order to determine the deviation of the orientation or positioning of each component. The positioning elements can advantageously be provided directly on the common reference plane and can extend up to each main component. The connection points between the main components and the positioning elements can be used to measure the changes in the position and orientation of the main components. Advantageously, an accurate determination of the position and orientation of the main components with respect to the common reference plane can be achieved in this way.

[0024] The displacement of the main components is electronically recorded via measuring means and can be calculated directly and / or simultaneously within the machine control system. Thus, the determined displacements, in particular the adjustment of the beam path of the optical module, can be compensated in order to improve the manufacturing quality of the components.

[0025] The individual main components can be directly mechanically connected to the common reference plane via positioning elements for setting a certain distance to the common reference plane, at least partially. This further development makes it possible, for example, to fix or position a main component mounted without fixation via a positioning element, for example composed of a thermally invariant material, such that a constant distance is always realized in the vertical direction between the common reference plane and the connection point between the positioning element and the main component. The floating bearing enables the main component to expand while the connection point to the positioning element remains a fixed point. The connection point to the positioning element is selected in particular such that the displacement of the main component has as little influence as possible on the component quality of the component to be manufactured.

[0026] The common reference plane can advantageously be the reference plane of the optical module. This particularly advantageous definition of the reference plane enables an easy and efficient determination as well as an accurate compensation of the position and orientation of the main components.

[0027] Particularly advantageously, the basic elements are designed to form a rack that (especially completely) surrounds the process chamber. This enables a particularly advantageous attachment to the main components, especially the basic elements of the process chamber. In addition, thermal expansion can be compensated for by the basic elements up to at least a determinable maximum value.

[0028] Advantageously, the device can have at least one coater for preparing the powder material. The coater can be equipped with an alignment device. In order to keep the position and orientation of the alignment device constant, the alignment device can be directly connected to the reference surface by positioning elements, particularly preferably mechanically. The positioning elements can be designed as rods, bars, or thin beams made of a temperature-invariant material (as already described). This particularly advantageous design makes it possible to keep the distance between the alignment device and the common reference surface essentially constant and thus essentially unaffected by thermal expansion. Therefore, high component precision can be achieved particularly efficiently. Preferably, the positioning elements are oriented along the Z-axis so that changes in length along the Z-axis are prevented as much as possible.

[0029] Advantageously, the device can be equipped with a measurement system for the Z-axis, and thereby can be directly connected (or attached) to the reference surface by positioning elements in order to keep the position and orientation of the measurement system constant. The measurement system can also be provided as a measurement system for the lifting device.

[0030] Advantageously, it is possible to provide process monitoring systems, particularly a camera system, a powder bed monitoring system, and / or a melting point monitoring system, each of which is coupled to a common reference surface (preferably directly connected to the reference surface). Advantageously, these additional process monitoring systems are thus arranged independently of the process chamber and are directly connected or attached to the basic elements.

[0031] Advantageously, a method for manufacturing an object by means of the aforementioned device is proposed, which method may include determining the position and / or orientation of at least one main component relative to a common reference plane by means of at least one positioning element. Thus, particularly accurate manufacturing of the object can be achieved.

[0032] In addition, the process may include compensating for displacements determined directly or simultaneously by the machine control system by adjusting the beam path (in particular the optical module). Thus, particularly accurate manufacturing of the object can be achieved.

[0033] The method may further include determining the position and / or orientation of the main components using the individual main components and the associated positioning elements as a reference. As already described, the positioning elements made of thermally invariant material should be regarded as fixed points relative to the common reference plane, and thus, by determining the relative distance (or change in distance) of the main components with respect to each positioning element, simple and clear detection of the position and orientation of each main component is made possible.

[0034] In a further advantageous embodiment, the process chamber can be released along the release direction, in particular vertically, at the junction to the basic element, and the coupling element can further be provided with a coupling rod that couples the movement along the release direction with respect to the reference plane. The coupling rod can be designed as a positioning element and thus consists of a temperature-invariant material. The positioning element can also be designed as a rod directly attached to the common reference plane. The device can also have a lifting device for vertically positioning the construction panel. In addition, a construction cylinder may be provided for guiding the construction panel. Both the lifting device and the construction cylinder may be directly attached to the base member. All main components may be provided separately, in particular on the basic element, spaced apart from the process chamber.

[0035] Advantageously, the individual main components can be separated and connected to the basic elements, and the main components can be aligned with each other via a common reference plane. Advantageously, the process chamber can be mounted independently of the optical module on the basic element. In this regard, the process chamber may include a process chamber housing to provide a working space sealed from the environment during the construction process.

Brief Description of the Drawings

[0036]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5a

Figure 5b

Modes for Carrying Out the Invention

[0037] Detailed Description of Preferred Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to exemplary figures. The functions of the embodiments may be combined in whole or in part, and the present invention is not limited to the described embodiments.

[0038] FIG. 1 shows a schematic embodiment of a manufacturing plant based on optical interaction, in particular a manufacturing plant for selective laser melting (SLM system), in which the powder material to be processed is applied layer by layer to a movable base plate so that a three-dimensional workpiece (the object to be manufactured) can be generated by continuous application of the material, light irradiation, and melting of further layers (additive processing), and is locally remelted by focused laser irradiation.

[0039] For this purpose, the manufacturing plant provides at least one laser light source that generates a light beam via a control system coupled to the manufacturing plant, and this light beam is focused onto the material layer to be processed via an optical path with the help of various optical elements incorporated in the scanning head, such as a focusing lens or a diffusing lens, a mirror, an optical filter, etc. Then, the light beam is directed onto the material layer to be processed. The manufacturing plant has an optical module 9 for guiding the light beam.

[0040] In conventional SLM machines, there is a problem that major components such as the optical module, the build chamber (or process chamber), the coater, and the lifting device or Z-axis are usually directly or at least partially directly connected to or directly attached to the build chamber or process chamber. This causes undesirable changes in the system as a whole if the relative position and / or orientation of the elements change, for example due to thermal expansion or mechanical deformation, which distorts the manufacturing process and thus results in manufacturing errors, especially due to point positioning errors in the position and orientation of the laser beam within the powder plane. Compensation is only possible with very high effort due to the interaction of thermal deformations of the major components that are at least partially directly connected to each other.

[0041] In contrast, the present invention proposes the separation of the major components. For example, as shown in FIG. 1, the optical module 9 is directly attached to the basic element 3 at the first joint 0. Separately, the process chamber 1 is directly received on the basic element 3 at the second joint 13.

[0042] Particularly for the connection of the process chamber 1, a heat-insulating material, for example, a ceramic or plastic disk, or an insulating plate, is preferably used as an intermediate element of the bearing surface. The second joint 13 is a joint for connecting the basic element 3 to the process chamber 1, and it thus preferably enables heat insulation support. This enables thermal separation of the process chamber 1, which heats up to, for example, 50°C to 80°C during the operation of the system.

[0043] In FIG. 1, a single joint (or support point) is shown for the second joint 13. Preferably, the process chamber 1 can also be attached to the basic element 3 via several second joints (preferably via four joints). These second joints can essentially be arranged in a horizontal plane, and the process chamber 1 can be arranged thereon (preferably exclusively) with its lower side firmly connected. The first joint (to which the optical module 9 is attached) is preferably arranged at a distance (vertically and / or horizontally) from each of the second joints.

[0044] Preferably, the basic element 3 has a common reference plane 2 with respect to which the main components are arranged and positioned, and for example, to compensate for deformations, its relative position is used as position information. In an advantageous embodiment, the optical module 9 is directly received on this common reference plane 2 (for example, directly on the upper side of the basic element 3).

[0045] In addition, one or more positioning elements are provided, for example, extending vertically downward with respect to the main components. The positioning elements are, for example, positioning elements 4 or 8 designed to be thermally and mechanically separated from the main components while being fixed to the common reference plane 2. For example, the positioning element 4 can be suspended within the process chamber 1 or arranged laterally with respect to the process chamber 1 to enable an efficient position and orientation of the process chamber 1 with respect to the common reference plane 2. Advantageously, the positioning element 4 is not directly connected to the process chamber and simply functions as a distance scale or relative point for measuring relative distances. Specifically, the process chamber 1, the optical module 9, the lifting device 10, and / or the construction cylinder 11 can be regarded as main components.

[0046] In addition, in order to further improve the accuracy, if thermal displacements still occur, these displacements can be electronically determined via measuring means and preferably calculated directly and simultaneously in the machine control system. As a result, an additional process monitoring system 12 can also be provided. These process monitoring systems 12 can preferably be directly connected to and / or fixed to a common reference plane. Advantageously, a camera system for monitoring the equipment, as well as a powder bed monitoring system and a melting point monitoring system for monitoring the powder bed can be provided, which are directly coupled to the common reference plane 2, so that they are not subject to thermal and mechanical displacements and provide accurate and invariant data.

[0047] The adapter element 14 is advantageously provided between the optical module 9 and the process chamber 1. This adapter element 14 enables an airtight and laser-tight shielding from the environment, so that an optimal transfer of the laser beam from the optical module 9 to the process chamber 1 is ensured. In this context, the adapter element 14 is designed or connected flexibly such that a relative displacement of the process chamber 1 with respect to the optical module 9 without transmission of mechanical stress can be realized. The relative movement with simultaneous sealing can be realized by means of a diaphragm or a sealing ring.

[0048] The adapter element 14 is connected to the process chamber 1 at the joint such that relative movement between the process chamber 1 and the adapter element 14 is permitted in both the horizontal and vertical planes. For this purpose, a plurality of sealing rings and / or diaphragms may be provided at the joint. By using sliding bearings (preferably in both the horizontal and vertical directions) combined with the sealing rings and / or membranes, the relative movement of the connected process chamber 1 can be released while ensuring airtightness. Thus, the deformation of the process chamber 1 is not transmitted to the optical module 9 by the adapter element 14, but is compensated in an airtight and / or laser-safe manner by a specific connection of the adapter element 14. The mutual thermal and mechanical influences of the components can be minimized, and as a result, the manufacturing quality of the components can be significantly improved.

[0049] Furthermore, the protective glass can be integrated within the adapter element 14 to protect the optical module from the process atmosphere contaminated by particles within the process chamber 1. However, the protective glass must be firmly connected to the optical module 9 to prevent relative displacement of the protective glass with respect to the optical module.

[0050] FIG. 1 also shows a measurement system 6 that can be used to measure the Z-axis 7 and uses a positioning element 8 as a reference. Furthermore, the measurement system 6 can also be used to determine the position and orientation of the main components, such as the construction cylinder 11 and the process chamber 1. All measurement systems of the measurement system, preferably the device, are referenced to a common reference plane 2, particularly via the positioning element. By using the positioning element 8 as a reference element, the accurate position and orientation of the main components can be determined. The positioning element is made of a temperature-invariant material. The temperature-invariant material is, for example, invar or a fiber-reinforced plastic such as carbon fiber-reinforced plastic or glass fiber-reinforced plastic.

[0051] The construction cylinder 11 includes, for example, a lifting device 10 that is movable in the vertical direction in order to raise or lower the base plate with respect to circumferential direction conversion. To start the construction process, a layer of material powder is deposited and leveled on the plate by an alignment device (or coater 22). During the forming process, after successive application of layers and merging of the desired sections, the lifting device 10 gradually descends to enable a new application of the material powder layer in the construction field each time.

[0052] As shown in FIG. 1, further measuring means 5 capable of detecting the relative position of the lifting device 10 are also provided. The displacement is determined here, for example, in the vertical direction. In parallel with this, the positioning element 8 can be provided laterally with respect to the measuring means 5 in order to determine the relative positioning of the individual main components and the position or zero point of the measuring system 5. The positioning element 8 is thereby preferably directly connected to the common reference plane 2. Since the positioning elements are made of a thermally invariant material, they do not essentially take shape due to thermal effects and remain of constant length. Therefore, the distance between the positioning element and the common reference plane 2 can be considered to be essentially constant. The measuring means 5 are provided to determine the position and orientation of the forming platform of the lifting device 10. For this purpose, the measuring means 5 may be present, for example, within the lifting device 10 or parallel to the lifting device 10. In addition, the measuring means 5 can have a positioning element arranged within the cylinder of the lifting device 10 in order to provide a fixed reference for positioning. Specifically, a laser distance sensor can be used as the measuring means 5, or a tactile measuring device such as a touch sensor can be used.

[0053] Each of the positioning elements provides a fixed point with respect to a common reference plane, and these fixed points are used to readily determine displacements and / or changes in orientation of each major component. Thus, similar to using a ruler or scale fixed to the common reference plane 2, the displacement with respect to the common reference plane 2 is determined by measuring or determining the change in relative position between the major component and the positioning element, and the displacement determined via the machine control system is used to compensate the beam path in order to achieve the most accurate part accuracy possible when manufacturing the workpiece.

[0054] As shown in FIG. 1, two positioning elements 8 are arranged laterally spaced apart from the process chamber 1, whereby these positioning elements can be used not only to determine the position of, for example, the lifting device 10 and / or the cylinder 11, but also to determine the position of the process chamber 1. By providing two spaced parallel positioning elements 8, the position of the major component can be determined on two different sides, and as a result, changes in position and changes in orientation can also be determined easily and accurately.

[0055] The process chamber 1 is firmly connected to the basic element 3 at the second joint 13. However, as can be seen from FIG. 1, the thermal deformation of the process chamber 1 can result in a displacement of the center of the process chamber 1 with respect to the common reference plane 2. The process chamber 1 is also provided with at least one (preferably two) positioning elements 4. The positioning elements are designed to be thermally and mechanically separated from the process chamber 1. When the position of the process chamber 1 changes, the fixed points of the positioning elements 4 can be used to determine the exact position and orientation of the process chamber 1.

[0056] As shown in FIG. 1, the basic element 3 can advantageously comprise a base plate or basic element, side walls arranged on the base plate, and a lid to which the optical module 9 is attached. Preferably, the components of the basic element 3 are firmly connected to each other to form a stable rack.

[0057] Therefore, it is proposed to provide a process chamber 1 as a closed rack or a basic element 3 that houses or supports all of the main components. The individual components typically include an optical system having an optical module 9, a process chamber 1 or a build chamber, a lifting device 10, and a construction cylinder 11. This particular design results in a self - contained force flow, and there are no components that are affected by another component with respect to the application of force. Furthermore, the components can be accurately aligned with each other.

[0058] In addition, a plane is defined as a common reference plane 2 for the entire system. Advantageously, this is the reference plane of the optical system or the optical module 9. Precision - determining elements such as the main components are directly and thermally stably coupled to this plane. Thermal stability can be achieved, for example, by positioning elements made of Invar with a low coefficient of thermal expansion. Particularly preferably, the position and orientation of the optical module 9 with respect to the reference plane 2 (and the receiving element 3) can also be adjustable, for example, by bearings that can be adjusted vertically and / or horizontally.

[0059] Figure 2 shows an advantageous embodiment of the present invention that can be used separately or in combination with the embodiment shown in Figure 1. Figure 2 shows an alignment device or a powder layer adjustment unit. This alignment device can also be considered as an accuracy determination component or a main component. The alignment device having the scraper lip 20 of the coater 22 is part of a powder layer adjustment unit that can be used to homogenize the material powder on the base plate (or construction panel). To align the scraper lip 20, the scraper lip moves on the linear alignment beam 21. The fixing of the lip can be released and the lip can be pressed against the alignment beam 21. During the process, the geometric position, location, and orientation of the alignment beam 21 are transmitted to the scraper lip 20. Then, the fastening of the scraper lip 20 is resumed. The lip is thus firm again. Here, it is important that the position of the alignment beam 21 does not change during the operation of the machine, and as a result, the scraper lip 20 can always be aligned in a reproducible and error-free manner. Alignment errors become immediately apparent during the build-up process of the workpiece with a defective powder coating.

[0060] The accurate maintenance of the position and orientation of the alignment beam 21 is achieved by connecting it on both sides via a positioning element 23 to which the alignment beam 21 is fixed, and the positioning element 23 is directly connected or attached to the common reference plane 2. Moreover, the positioning element 23 is made of a material having a low coefficient of thermal expansion. Thus, the positioning element 23 is made of a temperature-invariant material in particular. Temperature-invariant materials are, for example, invar or fiber-reinforced plastics such as carbon fiber-reinforced plastics or glass fiber-reinforced plastics.

[0061] Another accuracy determination component is the measurement system of the Z-axis 7. Here too, thermal displacement results in inaccurate measurement values, which can directly affect the accuracy and metallurgical integrity of the components being manufactured. This is avoided by directly connecting (or at least partially supporting it at the positioning element) the measurement system to the common reference plane 2 via the positioning element 8. Ideally, the positioning element is also made of a material with a low coefficient of thermal expansion here.

[0062] Figures 3 and 4 show further embodiments of the present invention. Figure 3 shows the thermal expansion of the process chamber 1. By attaching the process chamber 1 to the second joint 13 on the basic element 3, it is thereby possible to allow the vertical expansion of the process chamber 1 such that they only exist on the lower side and without introducing stress to the basic element 3. The flexibly connected adapter element 14 allows the horizontal and vertical expansion of the upper side of the process chamber 1 without inducing stress on the basic element 3 or the optical module.

[0063] In Figure 3, the adapter element 14 is provided in such a way that it enables separation between the optical module 9 and the process chamber 1, whereby the optical module 9 and the process chamber 1 are each attached to the basic element. Thus, even in the case of thermal expansion of the process chamber 1, accurate beam guidance from the optical module 9 can be achieved.

[0064] To further improve accuracy, as shown in Figure 4, a positioning element made of a temperature-invariant material can be further provided, thereby enabling the determination of the accurate position and orientation of the main components, particularly the process chamber 1. The temperature-invariant material is, for example, invar or a fiber-reinforced plastic such as carbon fiber-reinforced plastic or glass fiber-reinforced plastic. For example, ceramics or glass can also be used.

[0065] Figures 5a and 5b show another manufacturing plant. Figure 5a shows a process chamber that thermally expands due to process heating. Since the separation of the main components is not achieved, the focus of the laser beam shifts. Figure 5b shows that deformation occurs not only in the vertical direction but also in the horizontal direction, thus showing a complex displacement of the laser beam. Thermal and mechanical deformations result in significant inaccuracies in component manufacturing.

Claims

1. 1. An apparatus for layer-by-layer formation of an object from powder material by optical interaction, in particular according to the method of selective laser melting, said apparatus comprising: a process chamber (1) for providing a working space within the area of ​​the build site; at least one optical module (9) of an illumination unit for spatially selectively illuminating the material present in the region of the building field; a lifting device (10) for vertically positioning a building panel to support said building site; a collective receiving element (3) for jointly connecting the individual main components of the device; Equipped with the optical module (9) is disposed on the receiving element (3) at a first joint, and the process chamber (1) is disposed separately from the optical module (9) at at least one spaced apart second joint on the receiving element (3); Device.

2. the individual main components, including the process chamber (1), the optical module (9), the lifting device (10) and / or the building cylinder (11), are mounted separately from one another directly on the receiving element (3); 10. The apparatus of claim 1.

3. at least one of the main components, including the process chamber (1), the optical module (9), the lifting device (10) and / or the building cylinder (11), is attached to the receiving element (3) in a thermally isolated manner, in particular by means of a heat insulating material; 10. The apparatus of claim 1.

4. a cooling unit for cooling the joint is provided at least at the second joint; 10. The apparatus of claim 1.

5. the process chamber (1) is attached to only one support point on the receiving element (3) and / or all functional carriers are attached separately from the process chamber (1), 10. The apparatus of claim 1.

6. the main components of the device are thermally and mechanically isolated from the process chamber (1), and an adapter element (14) is provided between the optical module (9) and the process chamber (1) for hermetic and / or laser safety shielding of the beam guidance area from the environment, 10. The apparatus of claim 1.

7. the adapter element (14) is designed to be flexible so as to allow a relative displacement of the process chamber (1) with respect to the optical module (9) without mechanical stress; 7. The apparatus of claim 6.

8. the adapter element (14) comprises a membrane and / or a sealing ring, 7. The apparatus of claim 6.

9. the adapter element (14) comprises an integrated protective glass for protecting the optical module (9) from a process atmosphere contaminated with particles, the protective glass being rigidly connected to the optical module (9) to avoid any relative displacement of the protective glass with respect to the optical module (9); 7. The apparatus of claim 6.

10. the individual main components have a common reference surface (2), and the individual main components are aligned with one another via the common reference surface (2) by positioning elements made of a temperature-invariant material, in particular Invar and / or fiber-reinforced plastics; 10. The apparatus of claim 1.

11. at least one of the main components is coupled to the common reference surface (2) by a positioning element for determining deviations in orientation or positioning of the respective component; 11. The apparatus of claim 10.

12. the displacements of the main components are determined electronically via measuring means (5) and are calculated directly and / or simultaneously in the machine control to compensate for the determined displacements, in particular by adjusting the beam path, 11. The apparatus of claim 10.

13. the individual main components are at least partially mechanically connected directly to the common reference plane (2) via positioning elements for setting a fixed distance to the common reference plane; 11. The apparatus of claim 10.

14. The reference surface of the optical module (9) is the common reference surface (2).

11. The apparatus of claim 10.

15. the receiving element (3) is a rack surrounding at least the process chamber (1), the receiving element (3) also surrounding the lifting device (10) and / or the building cylinder (11); 3. The apparatus of claim 2.

16. the apparatus further comprises a coater (22) for preparing the powder material, the coater (22) comprising an alignment device; In order to keep the position and orientation of the alignment device constant, it is directly connected to the common reference surface (2) by a positioning element (23).

11. The apparatus of claim 10.

17. the device comprises a Z-axis (7) measuring system (6), which is directly connected to the common reference plane (2) by a positioning element (23) in order to keep the position and orientation of the measuring system (6) constant; 11. The apparatus of claim 10.

18. a process monitoring system (12) including a camera system, a powder bed monitoring system, and / or a melting point monitoring system is provided, the process monitoring systems (12) each being coupled to the common reference surface (2); 11. The apparatus of claim 10.

19. A method for manufacturing an object by the device of claim 10, comprising: The position and / or orientation of at least one primary component relative to said common reference plane (2) is determined using a positioning element; the detected displacement is directly and / or simultaneously compensated by a machine control system by adjusting the beam path of the optical module (9), method.

20. the positioning element associated with each major component is used as a reference to determine the position and orientation of the major component; 20. The method of claim 19.

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