Cleaning device for cleaning three-dimensional objects

Abstract

Cleaning device (1) for cleaning three-dimensional objects (3) which have been produced by layering and selectively solidifying a powdered build-up material in the course of a build-up process, from surrounding, unsolidified powdered build-up material, comprising at least the following: a) a clamping device driven about at least one axis of rotation, in which an object (3) can be clamped and rotated about the at least one axis of rotation, and b) a handling device (12) with at least one mobile arm (10) which guides tool means by which the object (3) clamped in the clamping device can be cleaned from the surrounding, unconsolidated powdered building material and / or separated from support structures formed on the object during the construction process, wherein c) a control device is provided which controls the rotation of the clamping device about the at least one axis of rotation and the movement of the mobile arm (10) for cleaning the object (3) and / or separating the object (3) from the support structures in a parallel and coordinated manner, wherein d) the clamping device is arranged within a powder-tight cleaning chamber (4) with a wall in which at least one opening (8) is formed, and wherein e) the handling device (12) has a stationary base on which the at least one mobile arm (10) is movably mounted, characterized in that f) at least one bulkhead (16) controllable by the control device is provided, which can be controlled between a position releasing the opening(8) in the wall of the cleaning chamber (4) and a position closing the opening, and that g) the base (18) is arranged outside the cleaning chamber (4) such that the at least one mobile arm (10) can bring the tool means for use on the object (3) clamped in the clamping device through the opening (8) in the wall of the cleaning chamber (4), and that h) the control device is designed to control the bulkhead (16) into the position releasing the opening (8) when the at least one mobile arm (10) brings the tool means for use on the object (3) clamped in the clamping device and otherwise controls the bulkhead (16) into the position closing the opening (8).

Description

[0001] The invention relates to a cleaning device for cleaning three-dimensional objects, which have been produced by layer-by-layer application and selective solidification of a powdered build-up material in the course of a build process, from surrounding, unsolidified powdered build-up material, according to the preamble of claim 1.

[0002] A cleaning device is known from WO 2015 / 071184 A1. In this device, a swap body containing the object and a build platform for the object is attached to a rotating device. The swap body is then rotated at an angle of at least 90° from its upright position to allow any remaining unconsolidated powder to trickle out. Additionally, external vibrations are applied to the swap body to assist in removing powder from the object.

[0003] In DE 20 2016 003 042 A1, a pneumatic vibrator attached directly to a rotary table is disclosed, which sets the rotary table, on which the object is clamped, into vibrations, which are then transmitted to the object.

[0004] US 2009 / 0283109A1 discloses a generic cleaning device. DE 10 2017 206 815 A1 describes a method for cleaning a part manufactured using an additive manufacturing process, to which free-flowing material from the manufacturing process remains adhered. To remove the adhering material, mechanical energy is applied to the part (10) to loosen the adhering residues. The mechanical energy is introduced into the part using a cleaning tool.DE 10 2018 109 830 A1 describes a device for depowdering a build chamber of an additive manufacturing system, comprising at least two lances, each equipped with at least one nozzle, wherein the lances are arranged in at least one operating position in the build chamber adjacent to at least one additively manufactured component, a handling unit for moving the at least two lances relative to the build chamber and a supply unit for supplying a pressurized gaseous fluid.DE 10 2016 121 773 A1 describes an unpacking device for unpacking an additively manufactured three-dimensional object from the non-solidified building material surrounding it after completion of an additive manufacturing process, wherein the unpacking device is designed as a robot having at least three robot axes, in particular an industrial robot, wherein at least one unpacking tool, which is designed for unpacking an additively manufactured three-dimensional object from the non-solidified building material surrounding it after completion of an additive manufacturing process, is arranged or designed on one robot axis.

[0005] The object of the invention is to provide a cleaning device that ensures safe and effective cleaning of the object.

[0006] This problem is solved by the features of claim 1. Disclosure of the invention

[0007] The production of the three-dimensional object, such as a component or model, is therefore carried out using a layer-by-layer manufacturing process with the aid of computer data. This involves repeatedly applying thin layers of loose, powdered build material to a build platform, with each layer being selectively solidified to form a component or model cross-section. Solidification can be achieved, for example, chemically by selectively applying droplets of adhesive to defined areas of the loose, powdered build material layers using printing technology. Alternatively, loose, powdered build material can be selectively fused or sintered using high-energy radiation.

[0008] The cleaning of the object from loose, unconsolidated powdered building material in the cleaning device may involve completely unpacking the object and the building platform from the powder cake of loose powder, or it may simply involve cleaning off residues of loose powder from the object and the building platform that still adhere to the object and the building platform after unpacking.

[0009] The invention relates to a cleaning device for cleaning three-dimensional objects which have been produced by layering and selectively solidifying a powdered build-up material during a build-up process, from surrounding, unsolidified powdered build-up material, wherein the cleaning device includes at least the following: a) a clamping device driven about at least one axis of rotation, in which an object can be clamped and rotated about the at least one axis of rotation, and b) a handling device with at least one mobile arm which guides tool means by which the object clamped in the clamping device can be cleaned from the surrounding, unconsolidated powdered building material and / or separated from support structures formed on the object during the construction process, wherein c) a control device is provided which controls the rotation of the clamping device about the at least one axis of rotation and the movement of the mobile arm for cleaning the object and / or separating the object from the support structures in a parallel and coordinated manner, and wherein d) the clamping device is arranged within a powder-tight cleaning chamber with a wall in which at least one opening is formed, and wherein e) the handling device has a fixed base on which the at least one mobile arm is mounted so as to be movable and driven.

[0010] Support structures are defined here as structures that were integrally molded onto the object during the construction process for manufacturing reasons or for stiffening, and which include, for example, thin struts or ribs that connect sections of the object, but no longer have a function in the finished object and therefore must be removed.

[0011] Parallel and coordinated control of the rotation of the clamping device and the movement of the mobile arm of the handling device by the control device means that a spatial alignment takes place between the object clamped on the clamping device and the tool means guided (straight) by the mobile arm in such a way that the tool means can clean the object of the mounting material and / or separate the support structures from the object. According to the invention, it is provided that f) at least one bulkhead controllable by the control device is provided, which is controllable between a position releasing the opening in the wall of the cleaning chamber and a position closing the opening, and that (g) the base is arranged outside the cleaning chamber in such a way that the at least one mobile arm can bring the tooling means for use on the object clamped in the clamping device through the opening in the wall of the cleaning chamber, and that h) the control device is designed to control the bulkhead into the opening-releasing position when the at least one mobile arm brings the tooling means to use on the object clamped in the clamping device and otherwise controls the bulkhead into the opening-closing position.

[0012] For example, with the bulkhead initially in the closing position of the opening and the mobile arm consequently positioned outside the cleaning chamber by the electronic control unit, a first portion of the loose build-up material can be cleaned from the object simply by rotating the turntable around at least one axis and optionally activating a vibrator. Only then does the electronic control unit move the bulkhead into the position releasing the opening, and the mobile arm is guided through the opening to deploy the tool it carries on the object clamped in the clamping device, in order to clean a second portion of the build-up material from the object and / or to separate the support structures from the object. These measures largely protect the handling device from contamination by the loose build-up material.

[0013] Preferably, the tooling includes tools that can be picked up and / or changed by the mobile arm of the handling device as needed.

[0014] According to a further development, a vibrator is provided which is controlled by the control device in such a way that it sets the clamping device into vibrations at least during rotation about at least one axis.

[0015] According to a further development of the cleaning device, the clamping device can be pivoted about a first axis of rotation and a second axis of rotation that is perpendicular to the first axis of rotation.

[0016] The cleaning device comprises, for example, a first motor which rotates a turntable via at least one first drive shaft. The object can be detachably clamped onto the turntable by means of a clamping device. The turntable is arranged in the cleaning chamber in which the cleaning of the object takes place. At least the turntable, the first motor, and the first drive shaft are mounted to rotate on a rotary arm, which is driven by a second motor to rotate about a second axis of rotation. This second axis of rotation is perpendicular to the first axis of rotation about which the turntable is driven by the first motor.

[0017] According to a further development, the turntable is driven by the first motor to rotate about the first axis of rotation within an angular range of 0 degrees to 360 degrees, and the rotary arm is driven by the second motor to rotate about a second angular range of 0 degrees to 360 degrees. Preferably, multiple rotations about the first axis of rotation and / or the second axis of rotation are performed.

[0018] These measures provide a simple structural possibility to rotate an object detachably clamped to the turntable around two axes of rotation (two degrees of freedom) and within a maximum angular range in each case, in order to support the removal of unconsolidated superstructure material from the object.

[0019] The tools and equipment may include at least the following: a) Means for dry ice blasting the object, and / or b) Means for glass bead blasting the object, and / or c) Means for removing the surrounding building material from the object by flowing a fluid over the object, and / or d) Means for separating at least one support structure from the object, for example a milling cutter or a saw.

[0020] Preferably, the handling device is formed by an industrial robot.

[0021] In summary, cleaning is carried out by shaking and / or pivoting around, for example, two axes of rotation in a closed cleaning chamber. If necessary, the cleaning chamber is flooded with protective gas and / or dusted using extraction. After the object has been (largely) depowdered, the dissolved powder is removed from the cleaning chamber (preferably by automatic extraction) and returned to the material cycle or material preparation (sieve). Once the powder has been removed from the cleaning chamber, the gas-tight / dust-tight seal is moved to the opening position, and the handling device then removes any remaining support structures, for example, with a milling cutter or a chisel tool. During this process, the handling device or...Its mobile arm and a rotary-swivel device, which pivots the clamping device, are coordinated and controlled in parallel to optimally position / move the object in relation to the tooling guided by the arm. The tooling guided by the arm can also perform cleaning and surface finishing of the object, such as blowing out contaminants, glass bead blasting, or dry ice blasting. The handling device, or its mobile arm, can also transfer the object to further processing devices, for example, a sawing device to separate the component from the build platform.

[0022] Advantageous embodiments of the invention are described in the claims, the description, and the drawings. The advantages of features and combinations of features mentioned in the introduction to the description are merely examples and can be achieved alternatively or cumulatively, without necessarily requiring that the advantages be obtained by specific embodiments of the invention. Further features can be seen in the drawings—in particular, the geometries and relative dimensions of several components, as well as their relative arrangement and functional connection. The combination of features from different embodiments of the invention or features from different claims is also possible, deviating from the chosen cross-references in the claims, and is hereby encouraged. This also applies to features that are illustrated in separate drawings or mentioned in their description.These features can also be combined with features from different patent claims. Likewise, features listed in the patent claims can be omitted for further embodiments of the invention. drawing

[0023] An embodiment of the invention is illustrated in the drawing below and explained in more detail in the following description. The drawing shows Fig. 1 a side view of a cleaning device according to a preferred embodiment of the invention with a handling device which is in the inactive state; Fig. 2 the cleaning device of Fig. 1 with the handling device in the active state; Description of the exemplary embodiment

[0024] Fig. 1 and Fig. Figure 2 shows a side view of a preferred embodiment of a cleaning device by which unsolidified powdered build material is cleaned from a three-dimensional object (not shown). The object, for example, a component or a model, was produced on a build platform (also not shown) by layer-by-layer application and selective solidification of the powdered build material. In the present case, the selective solidification of the powdered build material was carried out by means of high-energy radiation, in particular by means of laser sintering (laser radiation).

[0025] The cleaning process here is intended solely to remove residual powder that adheres to the object after it has been unpacked from the powder cake. The cleaning device 1 is controlled, for example, by an electronic control unit (not shown) which includes a CPU and whose operation is controlled by a computer program.

[0026] The construction process and the cleaning process are carried out, for example, at separate locations and in separate devices, namely in a layer construction device not shown here and the cleaning device shown here.

[0027] The object should, for example, have support structures which were integrally molded onto the object during the construction process for manufacturing reasons or for stiffening, and which include, for example, thin struts or ribs that connect sections of the object, but which no longer have a function in the finished object and therefore must be removed, for example, here in the cleaning device.

[0028] During the cleaning process, the object is clamped onto a rotary table of the cleaning device by means of a clamping device. The cleaning device comprises a dustproof cleaning chamber enclosed by a wall, in which the cleaning process takes place and which has a lockable first opening for loading and unloading the object, as well as a second opening for a mobile arm of a handling device.

[0029] The turntable can be driven to rotate about a first axis of rotation by means of a first motor, in particular at an angle of 0 to 360 degrees. Furthermore, the turntable is mounted on a rotary arm which can be rotated about a second axis of rotation by means of a second motor, the second axis of rotation being perpendicular to the first axis of rotation.

[0030] The turntable is driven by the first motor to rotate around its first axis of rotation, for example, within an angular range of 0 to 360 degrees, and the rotating arm is driven by the second motor to rotate within a second angular range of, for example, 0 to 360 degrees. The first and second motors are preferably servo motors controlled by an electronic controller to achieve the desired rotational positions of the turntable and thus of the object clamped on it. This allows the object clamped on the turntable to be rotated into a multitude of positions, which facilitates the removal of loose, unconsolidated powdered build-up material by the cleaning device. The cleaning device also includes, for example, a suction device (not shown here) for extracting the loosened powder material from the cleaning chamber.

[0031] A pneumatic vibrator can be mounted on the rotary table as an additional component of the cleaning device. This vibrator sets the rotary table, and consequently the object clamped to it, into vibration to detach loose powder particles from the object. The vibrator is controlled by the cleaning device's electronic control unit, which activates the vibrator as needed.

[0032] The object is further cleaned of the surrounding, unconsolidated powdered build-up material and separated from support structures molded onto the object during the construction process by tools guided by a mobile arm of a handling device, which in this case is implemented, for example, as an industrial robot. Preferably, the tools are picked up and / or changed by the mobile arm of the handling device as needed.

[0033] The tools guided by the mobile arm can include at least the following: a) Means for dry ice blasting the object, and / or b) Means for glass bead blasting the object, and / or c) Means for removing the surrounding building material from the object by flowing a fluid over the object, and / or d) Means for separating the support structures from the object, for example a milling cutter or a saw.

[0034] The rotation of the clamping device around its two axes and the movement of the handling device's mobile arm for cleaning the object and separating it from the support structures are controlled in parallel and coordinated fashion by electronic control. During rotation around its two axes, the turntable is preferably set into vibration by the vibrator.

[0035] Parallel and coordinated control of the rotation of the clamping device and the movement of the mobile arm of the handling device by the electronic control means that a spatial alignment takes place between the object clamped on the clamping device and the tool (straight) guided by the mobile arm in such a way that the tool can clean the object of the mounting material and / or separate the support structures from the object.

[0036] Furthermore, a bulkhead controllable by an electronic control device is provided, which can be controlled between a position that releases the second opening in the wall of the cleaning chamber and a position that closes the second opening.

[0037] The handling device has a stationary base on which a mobile arm is movably mounted, the base being arranged outside the cleaning chamber in such a way that the mobile arm can bring the respective guided tool through the second opening in the wall of the cleaning chamber for use on the object clamped in the clamping device on the rotary table.

[0038] The electronic control device is designed in such a way that it only controls the bulkhead into the position that releases the second opening when ( Fig. 2) when the mobile arm brings the respective guided tool to use on the object clamped in the clamping device and otherwise controls the bulkhead into the position closing the second opening ( Fig. 1).

[0039] For example, in the position of the bulkhead closing the second opening, and with the arm consequently positioned outside the cleaning chamber by the electronic control, a first part of the loose build-up material can be cleaned from the object simply by rotating the turntable around the two axes of rotation and activating the vibrator ( Fig. 1) Only then is the bulkhead controlled by the electronic control into the position releasing the second opening and the mobile arm guided through the second opening to bring the tool it guides into use on the object clamped in the clamping device on the turntable, in order to clean a second part of the assembly material from the object and / or to separate the support structures from the object ( Fig. 2) These measures protect the handling equipment from unnecessary contamination by the loose assembly material.

Claims

[1] Cleaning device (1) for cleaning three-dimensional objects (3) produced by layering and selectively solidifying a powdered build-up material during a build-up process, from surrounding unsolidified powdered build-up material, comprising at least the following: a) a clamping device driven about at least one axis of rotation, in which an object (3) can be clamped and rotated about the at least one axis of rotation, and b) a handling device (12) with at least one mobile arm (10) which guides tool means by which the object (3) clamped in the clamping device can be cleaned from the surrounding, unconsolidated powdered building material and / or separated from support structures formed on the object during the construction process, wherein c) a control device is provided which controls the rotation of the clamping device about the at least one axis of rotation and the movement of the mobile arm (10) for cleaning the object (3) and / or separating the object (3) from the support structures in a parallel and coordinated manner, wherein d) the clamping device is arranged within a powder-tight cleaning chamber (4) with a wall in which at least one opening (8) is formed, and wherein e) the handling device (12) has a stationary base on which the at least one mobile arm (10) is mounted so as to be movable and driven, characterized by , that f) at least one bulkhead (16) controllable by the control device is provided, which can be controlled between a position releasing the opening(8) in the wall of the cleaning chamber (4) and a position closing the opening, and that g) the base (18) is arranged outside the cleaning chamber (4) such that the at least one mobile arm (10) can bring the tool means for use on the object (3) clamped in the clamping device through the opening (8) in the wall of the cleaning chamber (4), and that h) the control device is designed to control the bulkhead (16) into the position releasing the opening (8) when the at least one mobile arm (10) brings the tool means for use on the object (3) clamped in the clamping device and otherwise controls the bulkhead (16) into the position closing the opening (8). [2] Cleaning device according to claim 1, characterized by that the clamping device is pivotable about a first axis of rotation and a second axis of rotation perpendicular to the first axis of rotation. [3] Cleaning device according to claim 1 or 2, characterized by that the tooling includes at least the following: a) Means for dry ice blasting the object (3), and / or b) Means for glass bead blasting the object (3), and / or c) Means for removing the surrounding construction material from the object (3) by flowing a fluid over the object, and / or d) Means for separating at least one support structure from the object (3). [4] Cleaning device according to any one of claims 1 to 3, characterized by , that the handling device (12) is formed by an industrial robot. [5] Cleaning device according to one of the preceding claims, characterized by , that the tooling includes tools which are picked up and / or changed as required by the mobile arm (10) of the handling device (12). [6] Cleaning device according to one of the preceding claims, characterized bythat at least one vibrator is provided which sets the clamping device into vibration at least during rotation about at least one axis.

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