Coater, filling device, system for applying a material layer, and method for additive manufacturing of a workpiece

Abstract

The present invention provides a coater 10 for applying a material layer to a carrier 31 of a machine tool 30, the machine tool 30 being configured to build a workpiece layer by layer from the applied material layer, the coater 10 including a base body 11 movable relative to the carrier 31 of the machine tool 30, a material storage chamber 12 having a filling chamber 13 carried by the base body 11 for storing a material 1, and an application device configured to empty the filling chamber 13 of the material storage chamber 12 by a first relative movement of the filling chamber 13 with respect to the base body 11 in order to apply the material 1 stored in the filling chamber 13 to the carrier 31.

Description

Technical Field

[0001] The present invention relates to a coater for applying a material layer, a filling device for use with the coater, a system for applying a material layer, and a method for additive manufacturing of a workpiece.

Background Art

[0002] In state-of-the-art technology, a primary forming process for additively manufacturing a three-dimensional workpiece is known, during which the workpiece is built up layer by layer from the provided material.

[0003] For this purpose, a material layer of powdery material is usually applied to a carrier of a machine tool, and then, for example, by fusing or sintering the individual material particles of the material layer, it is partially solidified into a workpiece layer by site-specific radiation.

[0004] Once the workpiece layer is solidified, a new layer of untreated material is applied to the support or the already manufactured workpiece layer, and site-specific irradiation is applied again.

[0005] In this way, the workpiece is continuously built up layer by layer from the material applied to the carrier in the form of a plurality of material layers.

[0006] This process usually includes a coater that spreads a certain amount of untreated material onto the carrier in order to apply a material layer of a predetermined thickness.

[0007] In the prior art, known coaters are moved relative to the carrier of a machine tool in order to spread a certain amount of material arranged on the carrier via a spreading element in a layer-forming manner, and the spreading element can be, for example, brush-shaped or lip-shaped. Such coaters are shown, for example, in DE202019103407U1 or EP2818305A1.

[0008] In order to increase the efficiency during manufacturing, attempts have been made to reduce the number of movement paths of the coater so that it is not necessarily returned to the starting or replenishing position in the stationary material reservoir after applying the first material layer and before a further material layer can be applied.

[0009] For this purpose, solutions are known from DE202019103407U1 or EP2818305A1, in which the coater has a material storage with a filling chamber, in which an amount of material is conveyed and, if necessary, applied onto a carrier by actuating a closing mechanism for opening and closing the lower outlet of the filling chamber. The applied material can then be spread in a layer-forming manner, in particular during the movement of the coater back to the starting position, and at the starting position the material storage can be replenished for the next cycle.

[0010] However, when actuating the closing mechanism, problems can be expected, in particular a loss of function associated with an incomplete opening and / or closing of the outlet, and an uncontrolled or incomplete application of the stored material onto the carrier. As a result, the material layer is not applied onto the carrier as desired, which in turn has an adverse effect on the manufacturing quality of the workpiece to be constructed.

Summary of the Invention

[0011] Therefore, the object of the present invention is to provide an improved possibility for a reliable and controlled application of material layers for the additive manufacturing of workpieces.

[0012] To solve this problem, a coater according to claim 1, a filling device according to claim 11 and a system for applying a material layer according to claim 15 are provided.

[0013] A further object of the present invention is to provide an improved possibility for the additive manufacturing of workpieces.

[0014] To solve this further problem, a method according to claim 16 is provided.

[0015] Each dependent claim refers to a preferred embodiment, and each of these can be provided individually or in combination.

[0016] According to a first aspect of the present invention, there is provided a coater for applying a material layer to a carrier of a machine tool, the machine tool being configured to build a workpiece layer by layer from the applied material layer. For this purpose, the coater includes a base body movable relative to the carrier of the machine tool, a material storage unit having a filling chamber carried by the base body for storing the material, and an application device configured to empty the filling chamber of the material storage device by a first relative movement of the filling chamber relative to the base body for applying the material stored in the filling chamber to the carrier.

[0017] The coater according to the first aspect provides a particularly efficient method for applying a material layer to a carrier, from which, in particular, for example, in the process of an SLM process (selective laser melting), the applied material layer is selectively melted or sintered by a laser beam-based processing device of the machine tool, and the workpiece is built layer by layer in the process of an additive manufacturing process.

[0018] The material to be applied is usually in powder form and preferably includes a metallic material such as an aluminum-based alloy, a steel-based alloy, a titanium-based alloy, a nickel-based alloy, or any other alloy suitable for use in the SLM process.

[0019] When referring to the carrier, for example, in the process of applying a material to the carrier and in the process of applying a material layer to the carrier, it shall also include all material layers and / or solidified workpiece layers that have already been applied to the carrier beforehand. Therefore, it shall also include the case where a further material layer is formed on the material layer and / or workpiece layer that already exists on the carrier.

[0020] In order to reduce the distance that the coater has to move for each layer of material to be applied, the coater advantageously transports an amount of material within the material reservoir in order to apply the material to the carrier as required and to apply a new layer of material to the carrier. In this way, the coater does not always have to return to its starting position at the stationary material dispenser and applies an amount of material to the carrier itself.

[0021] Thereby, the coater offers the particularly advantageous possibility of completely emptying the stored material during the first relative movement in which the entire filling chamber is moved. Thereby, a particularly wear-free operation of the coater is achieved, and a particularly reliable and always complete discharge of the material stored in the material reservoir is achieved.

[0022] Therefore, the coater does not require an additional closing mechanism for opening and closing the outlet opening of the filling chamber. Such closing mechanisms are known, for example, from DE202019103407U1 or EP2818305A1, which use a closing element movably mounted to close and open the opening of the filling chamber facing the carrier.

[0023] These closing mechanisms are exposed to increased loads due to constant contact with the usually powdery material, which can accumulate at the support points, guide joints, fitting parts, etc. of the movable closing mechanism and impair their function. Thereby, such deposits are promoted by the vibrations that necessarily occur during the movement of the coater.

[0024] This can lead to increased wear of the closing mechanism and, in certain situations, can also lead to blocking of the closing mechanism. As a result, the opening of the filling chamber can no longer be opened and closed as intended, which in turn leads to an uncontrolled distribution of the material contained therein.

[0025] By implementing the emptying of the filling chamber via the first relative movement, such a closing mechanism can be omitted, so that the stored material does not substantially contact or does not contact the support point or guide of the coater that could otherwise be adversely affected. This ensures functionality, especially low-wear operation.

[0026] The first relative movement also ensures that the filling chamber is completely emptied since the entire filling chamber moves. As a result, the flow limit of a normally powdery material is substantially stationary and can be exceeded more easily than in the case of a filling chamber in which only the lower opening is opened / opened by a closing mechanism and the rest is substantially stationary. In this case, so-called bridging occurs and there is a risk that the material in the filling chamber is "pushed" or "packed" so that the material does not move or does not start to flow.

[0027] On the other hand, the movement of the filling chamber itself applies an additional dynamic force to the material, so that even low-fluidity materials, especially powdery materials, can be distributed in a reliable and complete manner.

[0028] In a preferred embodiment, the coating device comprises a rotatable support, via which the material reservoir is supported relative to the substrate about a rotation axis such that the first relative movement for emptying the filling chamber is a rotation about the rotation axis.

[0029] In this way, a particularly effective method for emptying the filling chamber is provided, in the process of which the filling chamber can be moved, for example, from an initial position (where the opening is usually vertically upward) to an overhead position (rotated 180° and the opening is usually vertically downward). As a result, the material filled through the opening in the filling chamber is removed from the filling chamber by gravity and applied to the carrier via the same opening. By completely "tilting" the filling chamber relative to the substrate to an overhead position, all the material stored in the filling chamber can be reliably applied without any residual material remaining in the filling chamber.

[0030] Preferably, the rotation axis extends parallel to the surface of the carrier and perpendicular to the moving direction of the substrate.

[0031] Thereby, the coating device is preferably configured to rotate the filling chamber by a predetermined angle from an initial position where the filling chamber is filled to an end position, and the predetermined angle is preferably from 90° to 270°, particularly preferably 180°.

[0032] Preferably, the angular position of the filling chamber with respect to the substrate of the coater is indicated based on the zenith angle between a reference line of the filling chamber fixed to the filling chamber and the vertical direction directed with respect to the earth's gravitational field. In cross-section, the reference line starts from the center point of the filling chamber and extends perpendicular to the rotation axis passing through the opening of the filling chamber. The zenith angle at the initial position of the filling chamber is preferably 0°, and the zenith angle at the end position of the filling chamber is from 90° to 180°, particularly preferably 180°.

[0033] In a preferred embodiment, the coater comprises a spreading element attached to the substrate, and this spreading element is configured to spread a certain amount of material arranged on the carrier in a layer formation manner by the movement of the substrate.

[0034] In this way, a particularly uniform application of the material layer to the carrier can be carried out, for example, by spreading a certain amount of material arranged as a deposit on the end side on the surface of the carrier onto the carrier via the spreading element.

[0035] Spreading is mainly understood as sweeping the material, and in the process, the spreading element pushes out the material accumulated during the movement of the substrate in front of itself, while transporting the material through a gap of a predetermined size between the spreading element and the carrier, and thus spreading the material in a layer formation manner.

[0036] In a preferred embodiment, the substrate can move back and forth relative to the carrier, particularly translationally, between a first end position and a second end position. The coater is configured to spread a first amount of material onto the carrier via a spreading element in a layer-forming manner by a first movement of the substrate from the first end position to the second end position. When reaching a coating position located between the second end position or the first end position and the second end position, it is further configured to empty the filling chamber of the material reservoir by a first relative movement in order to apply a second amount of material to the carrier.

[0037] Preferably, when reaching the second end position or the coating position, the coater is configured to spread the second amount of material applied to the carrier in a layer-forming manner by a second movement of the substrate from the second end position to the first end position via a spreading element.

[0038] In this way, unnecessary movement of the coater is avoided, and two material layers can be applied in one cycle from the first end position to the second end position and back again. The advantageous design of the coating device enables a controlled application of the material for forming the second material layer without residues of the material remaining in the filling chamber, so that a material layer of a certain quality can be applied to the carrier.

[0039] In a preferred embodiment, the coating device comprises a drive unit, particularly an electric drive unit, connected to the material reservoir and configured to cause a first relative movement of the filling chamber.

[0040] In a preferred alternative embodiment, the coating device comprises an actuating element connected to the material reservoir, and the actuation of this actuating element causes a relative movement of the filling chamber with respect to the substrate.

[0041] Actuation should here be understood as a mechanical interaction involving the transmission of force and / or torque to the actuating element that causes the relative movement of the filling chamber.

[0042] In this way, the coating device does not depend on an internal drive unit, etc., but can be operated by the interaction between the operating element and other elements. This reduces the cost and maintenance effort compared to a design having a drive unit.

[0043] In a preferred embodiment, the coater comprises a first contact element attached to a machine tool, particularly a carrier, and the coater is configured to operate the operating element by the movement of the substrate, particularly the first movement of the substrate, through the interaction with the first contact element so as to cause a first relative movement for emptying the filling chamber.

[0044] In this way, the operation of the coating device for emptying the filling chamber is advantageously initiated by the movement of the coater itself as soon as the operating element interacts with the first contact element. Thereby, other necessary drive units in the coater can be omitted, reducing the cost, installation space, and maintenance effort.

[0045] Furthermore, the mechanical interaction represents a reliable "limit switch" that always empties the filling chamber at the same position during the movement of the substrate, which is safe against failures compared to an electronic limit switch.

[0046] Examples of the combination of the operating element and the first contact element are the combination of a contact disk and a rolling contact element (see FIG. 1), the combination of a toothed wheel disk and a toothed rack (see FIG. 2), the combination of an eccentric crank and a profile body (see FIG. 3), or any kind of combination of slides or guides with slots.

[0047] In a preferred embodiment, the coater comprises a second contact element attached to a machine tool, and the coater is configured to operate the operating element by contacting the second contact element by the movement of the substrate so as to cause a second relative movement of the filling chamber with respect to the substrate, as a result of which the filling chamber is brought to an initial position suitable for replenishing the material to be stored in the filling chamber.

[0048] In this way, a fully automated series of movements of the filling chamber is carried out, which depends only on the movement of the substrate of the coater.

[0049] In a preferred alternative embodiment, the coater comprises a restoring element connected to the material storage part, and this restoring element causes a second relative movement of the filling chamber with respect to the substrate, as a result of which the filling chamber is brought to an initial position suitable for replenishing the material to be stored in the filling chamber, and exerts a restoring force on the material storage part to cause the second relative movement.

[0050] In this way, after the first relative movement has been carried out, the filling chamber can be returned to its initial position by the restoring force, which occurs especially when the actuating element no longer interacts with the first contact element.

[0051] According to a second aspect of the present invention, there is provided a filling device for filling the material storage part of a coater, which is configured to apply a layer of material to a carrier of a machine tool, and is thereby movable relative to the carrier, comprising a storage chamber for storing the material, and a supply storage part having an outlet opening for discharging the material stored in the storage chamber, and a distribution device arranged on the supply storage part, which is configured to be carried from a first position where the outlet opening is closed to a second position where the outlet opening is opened by the movement of the coater, so that the material stored in the storage chamber is filled into the material storage part of the coater through the outlet opening. In particular, the machine tool is configured to build a workpiece layer by layer from the material layer applied by the coater.

[0052] In this way, the movement of the coater itself acts as a trigger for filling or replenishing its material storage part, and thus does not require, for example, an electronic limit switch that starts filling via a metering screw as soon as the coater reaches its replenishment position below the outlet opening of the supply storage part.

[0053] Furthermore, since the actuating force required to operate the dispensing device is provided entirely by the coater itself, no direct drive is required, for example via an electric motor, to relatively drive the mechanical closing components of the supply reservoir.

[0054] Accordingly, the filling device is designed as a passive and essentially stationary device attached to the machine tool for interaction with the movable coater in order to fill its material reservoir by means of said interaction.

[0055] The outlet opening remains closed without interaction with the coater, so that, for example, when the coater moves to another location to apply a layer of material, the storage chamber of the supply reservoir can be supplied with a further amount of material for a subsequent filling process.

[0056] Preferably, the dispensing device comprises a restoring element that closes the outlet opening by applying a restoring force as soon as the coater no longer interacts with the filling device, for example as a result of the loss of contact when the coater moves from its replenishment position.

[0057] In a preferred embodiment, the dispensing device is designed as a sliding element having a contact portion that is movably attached to the supply reservoir, contacts the coater during the latter's movement, and is designed to displace the sliding element from a first position to a second position as the movement progresses.

[0058] In this way, an interaction without transmission between the filling device or its dispensing device and the coater can be provided, whereby the operation of the dispensing device is effected by establishing contact at the contact portion. Accordingly, when installing the filling device on the machine tool, only the initial positioning of the contact portion according to the coater is required.

[0059] In order to be able to adapt to coaters of different dimensions, the sliding element preferably comprises adjustment means, such as a drawer, etc., in order to be able to adapt the position of the contact portion with respect to the supply reservoir to the replenishment position of the coater.

[0060] As an alternative to the design as a sliding element, the dispensing device can also be designed as an inclined element having a lever portion which contacts the coater when the coater moves and tilts the inclined element from a first position to a second position as the movement progresses (in the sense of rotation about the support point of the inclined element).

[0061] In a preferred embodiment, the filling device further comprises a material reservoir and a dosing device configured to fill the storage chamber of the supply reservoir with a predetermined amount of material from the material reservoir.

[0062] This ensures that during each individual filling process, the storage chamber of the supply reservoir is always supplied with the necessary amount of material to be filled into the coater.

[0063] In a preferred embodiment, the supply reservoir comprises a further storage chamber for the material and a further outlet opening for discharging the material stored in the further storage chamber, and the dispensing device is configured to also close the further outlet opening in the first position and also release the further outlet opening in the second position.

[0064] In this way, the material storage part of the coater is filled as a result of the movement of the coater, and a further amount of material can also be simultaneously applied onto the carrier of the machine tool via the further outlet opening. Next, this further amount of material is spread onto the carrier in a layer-forming manner when the coater moves from the replenishment position.

[0065] Accordingly, a single movement of the coater in the filling device is advantageously utilized such that a first amount of material is automatically applied onto the carrier, substantially simultaneously a second amount of material is filled into the material reservoir of the coater, a first material layer is applied from the first amount, and thereafter, a second material layer is applied onto the carrier based on the material stored in the material reservoir.

[0066] According to a third aspect of the present invention, a system for applying a material layer to a carrier of a machine tool is provided. The machine tool is configured to build a workpiece layer by layer from the applied material layer, and includes a coater according to an embodiment of the first aspect of the present invention and a filling device according to an embodiment of the second aspect of the present invention configured to fill the material reservoir of the coater.

[0067] In this way, a system for depositing material layers by additive manufacturing is provided, which combines the above-mentioned advantages of the coater according to the first aspect and the filling device according to the second aspect.

[0068] In particular, in embodiments of the coater having operating elements, almost all operations for moving the material to be applied are caused or performed by the movement of the coater relative to the carrier of the machine tool.

[0069] Accordingly, the system according to the third aspect typically does not require electronic limit switches for adjusting the operation of the individual components, resulting in a simple and purely mechanical synchronization of the carrier, coater, and filling device, being safe against failures, cost-effective, and requiring little maintenance.

[0070] According to a fourth aspect of the present invention, a method for additionally manufacturing a workpiece using a machine tool is provided, the machine tool comprising at least a carrier and a coater for applying a material layer onto the carrier. In this case, the method comprises at least applying an amount of material stored in a filling chamber of a material storage of the coater to the carrier of the machine tool, applying a material layer to the carrier by spreading the amount of material applied from the filling chamber in a layer forming manner by the coater, and constructing a workpiece layer of the workpiece from a portion of the applied material layer by melting or sintering, and the step of applying an amount of material stored in the filling chamber of the coater to the carrier includes moving the filling chamber relative to the base of the coater carrying the material storage to empty the filling chamber.

[0071] Thus, the additive manufacturing process utilizes the advantages of uniform, fast and reliable application of the material layer, as already explained in connection with the coater of the present invention.

[0072] This enables efficient additive manufacturing of workpieces with low downtime and high manufacturing quality.

[0073] The material layer should usually be applied uniformly from a predetermined amount of material. However, due to irregular and sometimes incomplete application via a closing mechanism, fluctuations in the amount of material applied can occur, such that the material layer may not be completely applied, for example, because too little of the applied material results. When using a closing mechanism, in order to compensate for this problem, the material to be applied is usually overdosed beyond a predetermined amount.

[0074] On the other hand, the use of the coater according to the present invention enables complete discharge of the material stored therein due to the relative movement of the filling chamber for discharge, and therefore overdosing is no longer required, and thus material can be saved in the process of applying the material layer.

[0075] Similarly, as described for the coater according to the invention, the mechanical components of the coater are only slightly loaded by the material to be applied, so that inaccuracies caused by wear during the application of the material layer can also be reduced, and the service life when using the coater via additive manufacturing can be extended.

[0076] Preferably, depositing the material layer on the carrier by spreading the amount of material applied from the filling chamber in a layer-forming manner by the coater involves moving the substrate of the coater relative to the carrier of the machine tool.

[0077] Preferably, before applying the amount of material stored in the filling chamber of the material storage, the method involves applying a first amount of material to the carrier of the machine tool and filling the filling chamber of the material storage of the coater with the amount of material to be stored in the filling chamber.

[0078] In this way, the amounts of material required for two consecutive material layers are supplied together at one replenishment position of the coater.

[0079] Preferably, the method then involves applying a first material layer to the carrier by spreading the first amount of material applied to the carrier in a layer-forming manner, in particular by a first movement of the substrate relative to the carrier, and constructing a first workpiece layer of the workpiece to be manufactured from a portion of the first material layer applied by melting or sintering.

[0080] In this way, the first material layer is applied via the coater while simultaneously carrying the required amount of material for subsequent application of the material layer spread from the material stored in the filling chamber. This reduces the number of movements and thus also the manufacturing time. Once the coater reaches its end position and applies the first material layer, the first workpiece layer can be constructed immediately without the need to pre-return the coater to its starting position.

[0081] After the first work layer is constructed, the stored amount of material is discharged from the filling chamber, and then the above-described process steps continue.

[0082] However, preferably, the application of the stored amount of material can also be carried out simultaneously with the construction of the first work layer in order to further shorten the process time during manufacturing.

[0083] Its further aspects and advantages, as well as more specific embodiments of the foregoing aspects and features, will be described below with reference to the drawings shown in the accompanying figures.

Brief Description of the Drawings

[0084]

Figure 1A

Figure 1B

Figure 1C

[0085]

Figure 2

[0086]

Figure 3A

Figure 3B

Figure 3C

[0087]

Figure 4A

Figure 4B

[0088]

Figure 5A

Figure 5B

[0089]

Figure 6

[0090] It is emphasized that the present invention is in no way limited to the examples of the embodiments described below and their features. The present invention further encompasses modifications of the above embodiments, in particular modifications and / or combinations of individual or multiple features of the described embodiments within the scope of protection of the independent claims.

[0091] Figures 1A - 1C show schematic cross - sectional views of a first embodiment of a coater 10 according to the present invention at different positions during the movement of the base 11 of the coater 10.

[0092] The illustrated coater 10 comprises a base 11 and a material storage part 12 carried by the latter for material 1 to be applied in the form of a material layer to a carrier 31 of a machine tool by the coater 10 in order to build a workpiece layer of the workpiece thereon through additive manufacturing.

[0093] In the illustrated embodiment, the carrier 31 is plate - shaped, whereby the base 11 of the coater 10 is movable relative to the carrier 31 of the machine tool.

[0094] In the illustrated embodiment, the substrate 11 is movable back and forth between a first end position and a second end position relative to the carrier 31 along the illustrated x-direction, whereby the x-direction runs parallel to the surface of the plate-shaped carrier 31.

[0095] The coater is provided, on its underside, with a spreading element 19 facing the carrier 31, which spreading element 19 can be designed, for example, as a coater brush, a coater lip or a coater blade and is provided for spreading a layer of a certain amount of material 1 located on the carrier 31 during the movement of the substrate 11 between the first end position and the second end position (and vice versa).

[0096] In the illustrated embodiment, the material storage part 12 is cylindrical and has a filling chamber 13 with a semi-circular cross-section and an opening at the top in the initial position (see FIG. 1A), and the material 1 to be stored can be filled into the filling chamber 13 of the material storage part 12 through the opening. The material storage part 12 having the filling chamber 13 enables the storage and conveyance of the material 1 during the movement of the substrate 11.

[0097] In this way, during the first movement from the first end position to the second end position along the x-direction, during the first layer formation spreading of the first amount of material 1 on the carrier 31 by the spreading element 19, a second amount of material 1 can already be conveyed for the second layer formation spreading during a subsequent second movement in the drawn x-direction back from the second end position to the first end position.

[0098] When the substrate 11 reaches its end position relative to the carrier 31 at the end of the first movement, the coater 10 is configured to apply the amount of material 1 stored in the filling chamber 13 onto the carrier 31, as shown in FIGS. 1A to 1C in chronological order.

[0099] For this purpose, the coater 10 comprises, in the present example, a rotatable support of the material reservoir 12 and is provided with a coating device which empties the filling chamber 13 of the material reservoir 12 by means of a relative rotational movement of the filling chamber 13 with respect to the base body 11 (about the axis of rotation R).

[0100] To initiate the relative rotational movement, the coating device comprises an actuating element connected to the material reservoir, which in this case is designed as a semi-circular contact disk 15a.

[0101] The contact disk 15a is not limited to a semi-circular shape and can be designed as any partial or complete circle in the illustrated cross-section. The rotation of the contact disk 15a is thereby transmitted to the material reservoir 12, causing a relative rotational movement of the filling chamber 13.

[0102] The coater 10 further comprises a first contact element attached to the carrier 31, which in the present example is designed as a rolling contact element 16a. The coater 10 is configured to interact the contact disk 15a with the rolling contact element 16a such that the movement of the base body 11 along the x-direction causes a relative rotational movement for emptying the filling chamber 13.

[0103] Starting from the position of FIG. 1A, as the movement of the base body progresses, contact occurs between the contact disk 15a and the rolling contact element 16a (see FIG. 1B), as a result of which the contact disk 15a rolls on the rolling contact element and the rotation of the contact disk 15a is transmitted to the material reservoir 12 and its filling chamber 13, whereupon the material reservoir 12 is rotated relative to the base body 11 from its initial position in response to the rolling of the contact disk 15a.

[0104] Rotation causes a change in the position of the filling chamber 13, particularly the position of its opening relative to the substrate 11, whereby the powdery material 1 begins to flow relative to the filling chamber 13 as the rotation progresses and moves towards the opening of the filling chamber 13 so as to pass over the carrier 31. The relative movement ends at the position shown in Figure 1C where the filling chamber 13 is completely emptied.

[0105] The powdery material 1 does not come into contact with the mechanical components of the coater 10 such as the support points, guide joints, etc., which particularly reduces wear and extends the service life.

[0106] Similarly, moving the filling chamber 13 itself, the exemplary end at the overhead position of the filling chamber 13 shown in Figure 1C ensures that the filling chamber 13 is completely emptied without any residual material remaining in the filling chamber 13.

[0107] As shown in Figure 1C, an amount of material 1 is applied from the filling chamber 13 of the material storage to the carrier and can be spread in a layer-forming manner on the carrier 31 by the spreading element 19 in the second movement of the substrate 11 in the x direction.

[0108] Furthermore, the coater 10 also has a channel 14 on the left side in the illustrated cross-section, which extends from the upper side of the substrate 11 to the lower side facing the carrier 31. The channel 14 interacts here with a filling device (not shown here) and serves to directly supply the material 1 onto the carrier 31. This filling device fills the material into the filling chamber 13 of the material storage 12 and is configured to directly apply the material to the carrier 31 through the channel 14 so as to spread the latter in a layer-forming manner during the first movement, particularly while a further amount of material 1 is being carried into the filling chamber 13.

[0109] Figure 2 shows a schematic cross-sectional view of a second embodiment of the coater according to the present invention.

[0110] The design of the coater 10 corresponds to the design of the first embodiment in FIGS. 1A - 1C, except for the operating elements and the first contact elements of the coating device, and thus no further description will be given here.

[0111] The operating element of the second embodiment is designed as a toothed wheel 15b that interacts with a toothed rack 16b attached to the carrier 31 as the first contact element to cause a relative rotational movement of the filling chamber 13 based on a toothed mechanism.

[0112] Compared with the version having the contact wheel 15a and the rolling contact element 16a from FIG. 1, this version is more expensive but can better control the relative rotational movement because there is no slippage problem when rolling the contact wheel 15a.

[0113] In both the first and second embodiments, the first contact element - the rolling contact element 16a or the toothed rack 16b - is simultaneously the second contact element, and this second contact element interacts with the operating element - the contact disk 15a or the toothed wheel disk 15b - during the second movement of the base 11 so that the filling chamber 13 can be returned to its initial position via a second relative movement so that the filling chamber 13 can be refilled with the material 1 to be stored.

[0114] Another possibility for initiating the relative movement of the filling chamber 13 is shown in FIGS. 3A - 3C, which show perspective cross - sectional views of a third embodiment of the coater 10 according to the invention for different positions during the movement of the base 11.

[0115] The coater 10 shown comprises a base 11 which is only partially shown and a material storage 12 carried by the base 11 for storing the material to be applied by the coater 10 in the form of a layer of material to a carrier of a machine tool (not shown here) for constructing a layer of work on the work by additive manufacturing.

[0116] The substrate 11 of the coater 10 can be moved relative to the carrier of the machine tool. In the illustrated example, the substrate 11 can be translated back and forth along the illustrated x direction.

[0117] In the illustrated embodiment, the material storage unit 12 is cylindrical and includes a groove-shaped recess incorporated in a cylindrical shape as a filling chamber 13 having an opening on the cylindrical wall side, through which the material to be stored can be filled into the filling chamber 13 of the material storage unit 12.

[0118] The coater 10 includes a coating device disposed laterally with respect to the material storage unit 12. In this example, the coating device includes a rotatable support of the material storage unit 12 with respect to the illustrated portion of the substrate 11.

[0119] The support can be designed, for example, as a roller or a sliding bearing. The coating device is configured to empty the filling chamber 13 of the material storage unit 12 by the rotational movement of the filling chamber 13 with respect to the substrate 11 about the rotation axis R (see the positions of the filling chamber 12 in FIGS. 3A and 3B).

[0120] To initiate the relative rotational movement, the coating device includes an actuating element connected to the material storage unit 12, designed as an eccentric crank 15c. The eccentric crank 15c includes a pin positioned eccentrically with respect to the rotation axis R of the material storage unit 12 and configured to interact with the contact elements 16c, 16d on the machine tool side to cause the relative rotational movement of the filling chamber 13.

[0121] For this purpose, the coater 10 includes a first contact element attached to the machine tool, which is designed as a profile body 16c having a curved guide surface along which the pin of the eccentric crank 15c is guided in the process of the first movement along the x direction after contact is made, so as to cause the rotation of the eccentric crank 15c, which is transmitted to the material storage unit 12 and causes a relative movement to empty the filling chamber 13 (see FIG. 1B).

[0122] After reaching the end position (see FIG. 3C), the emptied filling chamber 12 can be returned to its initial position by interaction with a second contact element attached to the machine tool. Similar to the first contact element, the second contact element is also designed as a second profile body 16d having a curved guide surface on which the pin of the eccentric crank 15c is guided in the process of a second movement relative to the x-direction after contact has occurred, such that rotation of the eccentric crank 15c is transmitted to the material reservoir 12 and brings the filling chamber 13 to its initial position.

[0123] FIGS. 4A and 4B show a fourth embodiment of a coater according to the invention in a perspective view (FIG. 4A) and an enlarged cross-sectional view (FIG. 4B).

[0124] The coater 10 shown comprises a frame-shaped base body 11 which carries in a first recess a material reservoir 12 for storing the material to be applied by the coater 10 in the form of a material layer to a carrier of a machine tool (not shown here) for constructing a work layer of the work by additive manufacturing.

[0125] The base body 11 of the coater 10 can be moved relative to the carrier of the machine tool. In the example shown, the base body 11 can be translated back and forth along the x-direction shown.

[0126] The coater comprises, on its underside facing the carrier, a spreading element 19 which is designed in this case as a coater lip and is provided for spreading a certain amount of the material 1 located on the carrier during the movement of the base body 11.

[0127] In the embodiment shown, the material reservoir 12 is designed as a trough shaft in which a trough-shaped recess functions as a filling chamber 13 for the material.

[0128] The coater 10 comprises a coating device which comprises a rotatable support for the material reservoir 12 relative to the substrate 11, each having a lateral support point 17. FIG. 4B shows an enlarged cross-sectional view in the region of the front support point 17 from FIG. 4A, showing an implementation of the rotatable support via ball bearings.

[0129] The coating device is configured to empty the filling chamber 13 of the material reservoir 12 by means of a relative rotational movement of the filling chamber 13 with respect to the substrate 11 about the axis of rotation R.

[0130] To initiate the relative rotational movement, the coating device comprises an actuating element connected to the material reservoir 12, which in this example is designed as an eccentric crank 15c, similar to the embodiment shown in FIG. 3.

[0131] The eccentric crank 15c comprises a pin positioned eccentrically with respect to the axis of rotation R of the material reservoir 12, which is configured to interact with a contact element on the side of the machine tool (not shown here) in order to cause a relative rotational movement of the filling chamber 13 (see also FIGS. 3A - 3C). The eccentric crank 15c is screwed to one end face of the material reservoir 12 designed as a trough shaft, so that the rotation of the eccentric crank 15c is transmitted to the trough shaft.

[0132] Furthermore, the coater comprises an elastic return element 18 designed as a helical spring, which is connected to the material reservoir 12 via the eccentric crank 15c. The connection point is eccentric with respect to the axis of rotation R, so that the restoring force applied by the restoring element 18 applies a restoring torque to the material reservoir 12 in order to return it to an initial position suitable for filling the filling chamber 13 (corresponding to the position shown in FIG. 4A).

[0133] FIGS. 5A and 5B show schematic views of an embodiment of a machine tool 30 and a filling device 20 having a coater 10 according to the invention in various states.

[0134] FIG. 5A shows the coater 10 in the replenishment position, while FIG. 5B shows the coater 10 in the end position on the side opposite to the replenishment position.

[0135] The machine tool includes a carrier 31, a processing device 32 arranged to optically irradiate a material layer on the carrier with a laser beam 33, and a housing 34 that defines a processing space of the machine tool 30.

[0136] Furthermore, the machine tool 30 includes a coater 10 and a filling device 20 for filling the material storage portion 12 of the coater 10.

[0137] The coater 10 shown in FIGS. 5A and 5B may be a coater according to the first aspect of the present invention. However, the coater 10 includes a material storage portion 12 having a filling chamber that can be filled by the filling device 20. Therefore, as long as the material 1 stored therein can be transported translationally along the direction T in this case during the movement of the coater 10, it should not be limited thereto.

[0138] The coater 10 includes a through-channel 14 for directly passing the material 1 from the upper opening to the lower opening facing the carrier 31.

[0139] The filling device 20 includes a supply storage portion 21 having a storage chamber 22 for storing the material 1 and an outlet opening 22a for discharging the material 1 stored in the storage chamber 22, and is arranged on the supply storage portion 21 and designed as a sliding element 24. The outlet opening 22a (see FIG. 5B) is closed from the first position where the material 1 stored in the storage chamber 22 is filled into the material storage portion 12 of the coater 10 through the outlet opening 22a, and is displaced by the movement of the coater 10 to the second position (see FIG. 5A) where the outlet opening 22a is opened. It is provided with a dispensing device arranged to be displaced.

[0140] The sliding element 24 has a contact portion 24a oriented orthogonally to the moving direction T. This contact portion 24a comes into contact with the contact portion 24a during the movement of the coater 10. As the movement progresses, in this case, as the coater 10 moves from left to right, the sliding element 24 is designed to be displaced from the first position to the second position. During this process, the outlet opening 22a is released.

[0141] In this way, when the coater 10 moves to the replenishment position (see FIG. 5A), the material storage section 12 is mounted below the supply storage section 21 so as to be displaceable parallel to the moving direction T without an additional drive unit or the like, and is filled based on the displacement of the sliding element 24 caused by the coater 10 itself.

[0142] Therefore, the filling device 20 is arranged as a passive and substantially stationary device attached to the machine tool 30 for interaction with the moving coater 10, and this interaction causes the filling of its material storage section 12.

[0143] Furthermore, the filling device 20 further includes a further storage chamber 23 having a further outlet opening 23a, and this outlet opening 23a can also be opened and closed by the sliding element 24, preferably together with the other outlet opening 22a.

[0144] The material 1 discharged through the outlet opening 23a directly advances onto the carrier 31 through the through-channel 14 of the coater 10 and can be spread in a layer-forming manner during the movement from the replenishment position shown in FIG. 5A to the end position shown in FIG. 5B.

[0145] Furthermore, the filling device 20 includes a dosing device 26 arranged at the top opening of the supply storage section 21. This dosing device 26 is designed as a rotary valve in this example. Through this dosing device 26, the material 1 can be filled into the storage chambers 22 and 23 from the material reservoir 25 after the storage chambers 22 and 23 are emptied by the operation of the sliding element 24 by the coater 10.

[0146] In this way, another filling process of the material storage unit 12, or another discharge of the material onto the carrier 31 through the through-channel 14 of the coater 10 can be performed.

[0147] FIG. 6 shows a flowchart of an embodiment of the method according to the invention, including steps S1 to S7 for the additive manufacturing of a workpiece by a machine tool comprising at least a carrier and a coater for applying a material layer to the carrier.

[0148] In step S1, a first amount of material is applied onto the carrier of the machine tool.

[0149] In step S2, the filling chamber of the material storage unit of the coater is filled with a second amount of material to be stored in the filling chamber.

[0150] In step S3, a material layer is applied to the carrier by spreading the first amount of material applied to the carrier in a layer-forming manner, in particular by a first movement of the base of the coater relative to the carrier.

[0151] In step S4, a workpiece layer of the workpiece to be manufactured is constructed from a portion of the applied material layer by melting or sintering, in particular using a laser-based processing device of the machine tool.

[0152] In step S5, in order to empty the filling chamber, the second amount of material stored in the filling chamber is applied onto the carrier of the machine tool by moving the filling chamber relative to the base of the coater carrying the material storage unit.

[0153] In step S6, a further material layer is applied to the carrier by spreading the second amount of material applied to the carrier in a layer-forming manner, in particular by a second movement of the coater relative to the carrier.

[0154] In step S7, a further work layer of the work to be manufactured is constructed from portions of the further material layer applied by melting or sintering, in particular using a laser-based processing device of a machine tool.

[0155] Thereafter, steps S1 to S7 are repeated the required number of times to build up a number of work layers until the desired work is manufactured.

Explanation of reference numerals

[0156] 1 Material 10 Coater 11 Substrate 12 Material storage 13 Filling chamber 14 Through duct 15a Contact disk 15b Gear wheel 15c Eccentric crank 16a Rolling contact element 16b Rack 16c Profile body 16d Second profile body 17 Support point 18 Restoring element 19 Spreading element 20 Filling device 21 Supply storage 22 Storage chamber 22a Outlet opening 23 Further storage chamber 23a Further outlet opening 24 Sliding element 24a Contact portion 25 Material reservoir 26 Administration device 30 Machine tool 31 Carrier 32 Processing device 33 Laser beam 34 Housing

Claims

1. A coater (10) for applying a material layer to a carrier (31) of a machine tool (30), wherein the machine tool (30) is configured to construct a workpiece layer by layer from the applied material layer, a substrate (11) movable relative to the carrier (31) of the machine tool (30), a material storage section (12) carried by the substrate (11) and having a filling chamber (13) for storing a material (1), comprising: The coating device is configured to empty the filling chamber (13) of the material storage section (12) through a first relative movement of the filling chamber (13) relative to the substrate (11) in order to apply the material (1) stored in the filling chamber (13) to the carrier (31). A coater (10) characterized by that. Coater (10).

2. The coating device includes a rotatable support, and through the support, the material storage section (12) is supported so as to be relatively rotatable about the rotation axis (R) of the substrate (11) such that the first relative movement for emptying the filling chamber (13) is a rotation about the rotation axis (R). A coater (10) according to claim 1, characterized by that. Coater (10) according to claim 1.

3. The coater (10) includes a spreading element (19) attached to the substrate (11), and the spreading element (19) is configured to spread a certain amount of material disposed on the carrier (31) in a layer formation manner by the movement of the substrate. A coater (10) according to claim 1 or 2, characterized by that. Coater (10) according to one of claims 1 or 2.

4. The substrate (11) is movable relative to the carrier (31) between a first end position and a second end position, The coater (10) is configured to spread a first amount of material (1) on the carrier (31) through the spreading element (19) by a first movement of the substrate (11) from the first end position to the second end position in a layer formation manner while carrying a second amount of material (1) in the material storage section (12), When reaching a coating position located between the second end position or the first end position and the second end position, it is further configured to empty the filling chamber (13) of the material storage section (12) by the first relative movement in order to apply the second amount of material (1) to the carrier (31). A coater (10) characterized by that. The coater (10) according to claim 3.

5. The coater (10) is configured to spread, in a layer-forming manner, the second amount of the material (1) applied to the carrier (31) when reaching the second end position or the application position, by a second movement of the substrate (11) from the second end position to the first end position via the spreading element (19). The coater according to claim 4.

6. The coating device comprises a drive unit connected to the material storage unit (12), the drive unit being configured to cause a first relative movement of the filling chamber (13) with respect to the substrate (11). The coater (10) according to one of the preceding claims.

7. The coating device comprises an actuating element (15a; 15b; 15c) connected to the material storage unit (12), and the actuation of the actuating element (15a; 15b; 15c) causes a relative movement of the filling chamber (13) with respect to the substrate (11). The coater (10) according to any one of claims 1 to 5.

8. The coater (10) comprises a first contact element (16a; 16b; 16c) attached to the machine tool (30). The coater (10) is configured to actuate the actuating element (15a; 15b; 15c) by a movement of the substrate (11) via an interaction with the first contact element (16a; 16b; 16c) so as to cause a first relative movement for emptying the filling chamber (13). The coater (10) according to claim 7.

9. The coater (10) comprises a second contact element (16d) attached to the machine tool (30). The coater (10) is configured to actuate the actuating element (15a; 15b; 15c) by contacting the second contact element (16d) by a movement of the substrate (11) so as to cause a second relative movement of the filling chamber (13) with respect to the substrate (11), as a result of which the filling chamber (13) is brought into an initial position suitable for replenishing the material (1) to be stored in the filling chamber (13). The coater (10) according to claims 7 to 8.

10. The coater (10) comprises a restoring element connected to the material storage part (12) which exerts a restoring force on the material storage part (12) to cause a second relative movement of the filling chamber (13) with respect to the substrate (11), as a result of which the filling chamber (13) is brought into an initial position suitable for replenishing the material (1) to be stored in the filling chamber (13). The coater (10) according to any one of claims 1 to 8.

11. A filling device (20) configured to apply a material layer to a carrier (31) of a machine tool (30), wherein the material storage part (12) of the coater (10) is movable relative to the carrier (31), comprising a storage chamber (22) for storing the material and a supply storage part (21) having an outlet opening (22a) for discharging the material (1) stored in the storage chamber (22), characterized in that a dispensing device (24) is arranged in the supply storage part (21) and is configured to be moved by the movement of the coater (10) from a first position where the outlet opening (22a) is closed to a second position where the outlet opening (22a) is opened, so that the material (1) stored in the storage chamber (22) is filled into the material storage part (12) of the coater (10) through the outlet opening (22a). Filling device (20).

12. The dispensing device is a sliding element (24) movably attached to the supply storage part (21), having a contact part (24a) in contact with the coater (10) during the movement of the latter and designed to displace the sliding element (24) from the first position to the second position as the movement progresses. The filling device according to claim 11.

13. The filling device (20) further comprises a material reservoir (25) and a dosing device (26) configured to fill the storage chamber (22) of the supply storage part (21) with a predetermined amount of material (1) from the material reservoir (25). The filling device according to any one of claims 11 to 12.

14. The supply storage unit (21) includes a further storage chamber (23) for the material (1) and a further outlet opening (23a) for discharging the material (1) stored in the further storage chamber (23). The dispensing device (24) is configured to close the further outlet opening (23a) also in the first position and to release the further outlet opening (23a) also in the second position, characterized in that. The filling device according to any one of claims 11 to 13.

15. A system for applying a material layer to a carrier (31) of a machine tool (30), wherein the machine tool (30) is configured to build a workpiece layer by layer from the applied material layer. The coater (10) according to any one of claims 1 to 10, The filling device according to any one of claims 11 to 14 for filling the material storage unit (12) of the coater (10), Comprising System.

16. A method for additionally manufacturing a workpiece using a machine tool (30), wherein the machine tool (30) includes at least one carrier (31) and a coater (10) for applying a material layer to the carrier (31). Applying an amount of the material (1) stored in the filling chamber (13) of the material storage unit (12) of the coater (10) to the carrier (31) of the machine tool (30). Applying a material layer to the carrier (31) by spreading the amount of the material (1) applied from the filling chamber (13) in a layer formation manner by the coater (10). Constructing a workpiece layer of the workpiece from a portion of the applied material layer by melting or sintering. At least including The step of applying the amount of the material (1) stored in the filling chamber (13) of the material storage unit (12) of the coater (10) to the carrier (31) is Characterized by including moving the filling chamber (13) relative to the base body (11) of the coater (10) carrying the material storage unit (12) to empty the filling chamber (13). Method.

Images