3D printers permit three-dimensional objects to be generated. 3D printing may take place on a build platform within a 3D printer. The build platform may be part of a build unit which comprises the build platform and vertical walls extending around a build space or build volume in which 3D printing takes place. The vertical walls may be part of a frame of the build unit. The build platform is movable relative to the frame of the build unit and is lowered relative to the frame while 3D printing takes place. A print job may be printed by shaping an object layer by layer in a build material, such as powder or granulate. A layer of build material may be deposited and selected portions thereof may be solidified. This process may be repeated layer by layer to build solid objects within the build material. Upon finishing the print job, a printed job or cake is obtained, which includes a 3D object or 3D objects and build material which was not solidified. The remaining build material has to be removed later on to obtain the 3D object or the 3D objects.
Examples will now be described, by way of non-limited examples, with reference to the accompanying drawings, in which:
In the following detailed description, reference is made to the accompanying drawings. The examples in the description and drawings are to be considered illustrative and are not intended as limiting to the specific example or element described. Multiple examples may be derived from the following description and drawings through modification, combination of variation of certain elements.
Currently, upon printing a print job, the build unit with the printed parts inside may have to cool down for a long period of time or may be taken to a processing station to free up the build unit. In the processing station, the cake may be transferred to another container, in which the cake may cool down before uncaking takes place, i.e. before the 3D object or objects are separated from the non-solidified build material. The other container may be placed on top of the build unit and, thereupon, the cake, such as a hot cake, may be transferred from the build unit to the other container by pushing the build platform upwards. When the cake is transferred to the other container, a rigid sheet, or guillotine, may be used to separate the cake from the build platform of the build unit, wherein the guillotine may act as a base for the cake. Using the guillotine brings about the risk that parts in the cake are moved/shaked while the parts are still hot. In addition, using the guillotine brings about the risk that the position of the parts is shifted and that parts get in the way of the guillotine, which may result in damaged or destroyed parts.
Examples of the present disclosure provide a system helpful in automating print processes in 3D printers, which may eliminate human interaction to insert/remove a build unit from the 3D printer. According to examples of the present disclosure a printed job may remain within the build unit in which it was printed during cool down of the print job and, therefore, the risk of part quality issues may be reduced.
Examples of the present disclosure provide a 3D printer comprising: a printing machine to accommodate a build unit in a print position and a conveyor to move the build unit into the print position and out of the print position. The conveyor is to move the build unit vertically downward into the print position and to move the build unit vertically downward out of the print position. The build platform of the built unit is moved vertically downward relative to the a frame of the build unit as successive layers of build material are formed on the build platform and are selectively processed while the build unit is in the print position. In examples, the build unit is moved vertically downward into the print position before printing starts with the build unit in the print position and is moved vertically downward out of the print position after printing is finished.
Selectively processing may include selectively solidifying while the build unit is in the print position. Selectively processing may include applying a thermally curable binder agent. When using a thermally curable binder agent, the binder agent may be cured in a separate curing station upon completing the print job.
Printing machine 12 is to print 3D objects on build platform 28 while build platform 28 moves relative to the frame of the build unit. To this end, printing machine 12 includes print components 34 to apply material onto build platform 28 to generate 3D objects thereon. It is to be noted that
Printing machine 12 further includes a controller 36 communicatively coupled with conveyor 14 and print components 34. Controller 38 is to control print components 34 and conveyor 14 to perform methods and to obtain functionalities as described herein.
In examples, the build unit, which may also be referred to as construction box, is introduced vertically downward into the printer unit. During a 3D printing operation the build platform of the build unit is moved vertically downward as successive layers of build material are formed thereon and are selectively solidified. At the end of the 3D print job, the build unit is ejected vertically downward from the printer unit.
Conveyor 14 is to move build unit 16 vertically downward, arrow 20, into print position 18 while build platform 28 is in the pre-print position relative to the frame of build unit 16. Upon reaching print position 18, the frame of the build unit 16 may be latched in print position 18 and build platform 28 is moved vertically downward relative to the frame of build unit 16 during printing. Movement of build platform 28 relative to the frame of build unit 16 may be achieved using conveyor 14. Thus, in examples, conveyor 14 is to move build platform 28 relative to the frame of build unit 16 in the vertical direction while build unit 16 is latched in the print position 18. After printing, build platform 28 is in the post-print position shown in
In examples, moving the build unit vertically downward permits the system to use the same motor/conveyor to lower the build unit into the print position, to remove the build unit from the print position, and to move the build platform down while the build unit is in the print position.
In examples, the horizontal and vertical conveyors described herein may comprise conveyor lines. In examples, the vertical conveyor may comprise a vertical conveyor line or may comprise an elevator structure. In examples, vertical guide members, such as in the form of guide columns, may be provided, along which the build unit is moved using the vertical conveyor. The build unit may always be coupled to the column guide no matter if it's moving down or whether it's resting for printing. Conveyor may be to selectively engage with and disengage from the build platform and/or the frame of the build unit so as to move the build unit and/or the build platform as described herein.
In examples of the present disclosure, the build unit is moved through the 3D printer in the same direction in which the build platform of the build unit is moved relative to the frame of the build unit. Thus, in examples of the present disclosure, the same conveyor moving the build unit through the 3D printer may be used to move the build platform relative to the frame.
In examples of the present disclosure the printed job is extracted after it is completed without being transferred to another container. The printed job, i.e. the cake, may remain inside the container in which it was formed. Thus, moving the cake around and shaking it may be avoided. Leakage of build material, such as powder, may be avoided since moving around and vibrating parts inside a printed shop that is still hot may be avoided. A guillotine does not have to be used to separate the cake from the build platform. Thus, recently printed jobs are not exposed to the atmosphere and, therefore, modification of the cooling profile may be avoided. Not solidified build material, such as powder, inside the cake is not moved around during the transfer of the cake from the build unit to another container. Accordingly, quality issues may be reduced. In examples, the build unit may be inserted/removed from the 3D printer automatically. In examples, additional conveyors to provide the build unit to the conveyor which moves the build unit into and out of the print position may be provided. Thus, the process may be further automated. In examples, the cake is hot after printing and may cool down in the container in which it was printed. In examples, the cake may not be hot after printing, such as if using a binder agent. Thus, the cake may be a hot cake in case of a thermal fusing system or in case of a heat curable binder agent or may be a cold cake in case of UV curable binder agents.
In examples of the present disclosure, print jobs are printed directly in the container in which the cake is transported from the printing machine. In case of a hot cake, cooling down of the hot cake takes place after printing. Thus, the container where the parts are printed is the same as the container where they stay for cool down. Thus, the printed job may be stored for cooldown without shaking it. Since printing takes place in the container in which cooling down takes place, an additional build unit does not have to be provided. In examples in which no substantial heat is generated during printing, the present disclosure still provides an effective manner for continuous printing.
In examples, a plurality of build units may be moved into and out of the print position of the 3D printer one after the other. In examples, the build platform of a first build unit may be moved relative to the frame of the first build unit when the first build unit is in the print position and concurrently a second build unit may be moved in the vertical downward direction towards the print position. In examples, a third build platform may be moved away from the print position in a vertical downward direction while the first build unit is in the print position and/or while the second build unit is moved towards the print position. Accordingly, examples permit a plurality of build units to be handled in a time-saving manner and, therefore, permit the generation of 3D objects in a time saving manner. In examples, this may be achieved using the same conveyor.
In examples, the conveyor is to be engaged with the frame of the build unit to move the build unit into and out of the print position vertical downward and is to be engaged with the build platform to move the build platform relative to the frame vertically downward during printing while the build unit is in the print position.
Reference is made to
Thus, examples of the present disclosure provide two engagement mechanisms, a first one for effecting engagement and disengagement between the build unit and the conveyor and a second one for effecting engagement and disengagement between the build platform and the conveyor. The conveyor may be continuously moving down. In examples, the conveyor may be moving down in a stepped manner, at least during periods in which printing in a build unit takes place. When the build unit arrives at the print position it is disengaged from the conveyor and the build platform is engaged. After printing is finished, the build platform is disengaged from the conveyor and the build unit is re-engaged.
In examples, the first engagement mechanism is to effect engagement between the frame of the build unit and the conveyor to move the build unit into and out of the print position and to effect disengagement of the frame of the build unit from the conveyor during printing while the build unit is in the print position, and the second engagement mechanism is to effect engagement between the build platform and the conveyor during printing while the build unit is in the print position and to effect disengagement of the build platform from the conveyor when the build unit is moved into and out of the print position.
In examples, the first engagement mechanism comprises a first feature on the build unit and a second feature on the conveyor, which may be brought into and out of contact with each other to effect engagement and disengagement. In examples, the second engagement mechanism comprises a first feature on the build platform and a second feature on the conveyor, which may be brought into and out of contact with each other to effect engagement and disengagement. In examples, the first feature may be a driving dog and the second feature may be a following dog, or vice versa. In examples, the engagement mechanisms may be activated and deactivated to achieve engagement and disengagement magnetically, such as by controlling electromagnets of the engagement mechanisms.
In examples, the build platform is lockable relative to the build unit in the pre-print position and the post-print position. In such examples, the conveyor may be to be engaged with the build platform to move the build unit into and out of the print position and to move the build platform relative to the frame of the build unit, wherein the build platform is locked in the pre-print position while the build unit is moved into the print position, is locked in the post-print position while the build unit is moved out of the print position, and is not locked relative to the build unit during printing while the build unit is in the print position. In such examples, is in the engagement mechanism with the conveyor may be sufficient, wherein the part is moved by the conveyor is determined by the fact whether the build platform is locked to the frame or not. When the build platform is locked to the frame, the build platform is moved along with the frame. If the build platform is not locked to the frame and the frame is latched at the print position, the build platform is moved while the frame is not moved.
In examples, the build unit is locked in the print position upon reaching the print position. In order to lock the build unit in the print position, a stop may be provided, which may be arranged in the pathway of the build unit through the 3D printer so that, when the build unit hits the stop, it is arranged in the print position. When printing is finished, the stop may be removed from the pathway so that the build unit may be removed from the print position. In examples, at the same time that the build unit is locked into the print position, a feature of the same engagement mechanism that is otherwise used to attach the build unit to the conveyor may be used to attach the build unit at the desired position in the column guide.
In examples, the 3D printer comprises a first sensor to detect that the build unit reaches the print position when the conveyor moves the build unit into the print position, and a second sensor to detect that the build platform has reached a post-print position relative to the frame of the build unit after printing. In examples, the first sensor and the second senor are optical sensors. In examples, the second sensor is to monitor a driving force of the conveyor or a driving signal of the conveyor and to determine that the build platform has reached the post-print position using the monitored driving force or driving signal.
In other examples, a single barrier laser sensor may be provided. In such examples, a lowest/bottom part of the build unit may cross the barrier laser sensor when the build unit reaches the print position. Then, the frame of the build unit is disengaged and the build platform is engaged with the conveyor. When the print job is finished, the build unit is still held in the print position and, therefore, the conveyor is not able to move the build platform further. Thus, the conveyor will try to increase the force/driving signal, which may be a pulse width modulated signal. The increase in the force/driving signal may be detected as an indication that the print job is finished. Thus, the fact that the print job is finished may be detected by monitoring conveyor telemetry. Once it is detected that the job is finished, the build platform is disengaged and the frame is engaged allowing the printed job to move downward.
In other examples, a single barrier laser sensor may be provided to detect the lowest/bottom part of the build unit as an indication that the build unit reached the print position and to detect a feature of the build platform as an indication that the print job is finished. The output of such a single barrier laser sensor may be used to control the first and second engagement mechanisms as explained above.
As explained above, a single conveyor may be used to effect movement of the whole build unit on the one hand and to effect movement of the build platform relative to the frame of the build unit on the other hand. In other examples, a separate conveyor may be used to move the build platform relative to the frame of the build unit. Even in such case, movement of the whole build unit on the one hand and movement of the build platform relative to the frame of the build unit are in the same direction so that quality issues due to a change in the moving direction may be avoided.
Examples of the disclosure provide a 3D printer comprising a printing machine to accommodate a build unit in a print position, the build unit comprising a frame and a build platform movable relative to the frame, wherein the printing machine is to print 3D objects on the build platform while the build platform moves relative to the frame. A conveyor is to move the build unit into the print position and out of the print position in a first direction, and to move the build platform relative to the frame in the first direction while the build unit is in the print position. In such examples, the conveyor may be to be engaged with the frame of the build unit to move the build unit into and out of the print position, to be disengaged from the frame of the build unit while the build unit is in the print position, and to be engaged with the build platform to move the build platform relative to the frame during printing while the build unit is in the print position. In such examples, the 3D printer may comprise a first sensor to detect that the build unit reaches the print position, and a second sensor to detect that the build platform has reached a post-print position relative to the frame of the build unit after printing.
Examples of the present disclosure provide a method of 3D printing as shown in
As shown in
Examples described herein may be realized in the form of hardware, machine-readable instructions or a combination of hardware and machine-readable instructions. Any such machine-readable instructions may be stored in the form of volatile or non-volatile storage such as, for example, a storage device, such as a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or an optically or a magnetically readable medium, such as, for example, a CD, DVD, magnetic disk or a magnetic tape. The storage devices and storage media are examples of machine-readable storage, that are suitable for storing a program or programs that, when executed, implement examples described herein.
In the foregoing Detailed Description, it may be seen that various features are grouped together in examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed examples require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in less than all features of a single disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description, where each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it is to be noted that, although a dependent claim may refer in the claims to a specific combination with another claim or other claims, other examples may also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of each feature with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended to include also features of a claim to any other independent claim even if this claim is not directly made dependent to the independent claim.
Although some aspects have been described as features in the context of an apparatus it is clear that such a description may also be regarded as a description of corresponding features of a method. Although some aspects have been described as features in the context of a method, it is clear that such a description may also be regarded as a description of corresponding features concerning the functionality of an apparatus.
All the features disclosed in the specification, including any accompanying claims, abstract and drawings, and/or all the features of any method or progress described may be combined in any combination, including and claim combination, except combinations where at least some of such features are mutually exclusive. In addition, features disclosed in connection with a system may, at the same time, present features of a corresponding method, and vice versa.
Each feature disclosed in the specification, including any accompanying claims, abstract and drawings, may be replaced by other features servicing the same, equivalent or a similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example of a generic series of equivalent or similar features.
The foregoing has described the principles, examples and modes of operation. However, the teaching herein is not to be construed as being limited to the particular examples described. The above described examples are to be regarded as illustrative rather than restrictive, and it is appreciated that variations may be made in those examples by those skilled in the art without departing from the scope of the following claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/043073 | 7/23/2019 | WO | 00 |