Three-dimensional printing system with self-maintenance powder distribution subsystem

Abstract

To provide a three-dimensional printing system that can maintain uniformity and quality of a powder distribution layer, and a method of manufacturing a three-dimensional article.SOLUTION: A three-dimensional printing system 2 for manufacturing a three-dimensional article comprises: a build chamber 6; an overflow chamber 16 adjacent to the build chamber; a motorized build plate 8; a powder coater 18 including a vibration generator; a lateral movement mechanism 20 coupled to the powder coater; and a controller 36. The controller is configured to perform a process to remove accumulated powder from surfaces of the powder coater according to the following steps: (1) a step of operating the lateral movement mechanism to position the powder coater over a location outside of the build chamber; and (2) a step pf operating the vibration generator to shake the accumulated powder into the location outside of the build chamber. The location outside of the build chamber can be defined by the overflow chamber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an apparatus and method for fabricating a three-dimensional (3D) object using a powder material. More particularly, the present disclosure relates to an apparatus and method for maintaining proper operation of a powder dispensing and metering system.

Background Art

[0002] Three-dimensional (3D) printing systems are rapidly increasing in use for prototyping and manufacturing purposes. One type of 3D printer forms a 3D object to be manufactured from a powder material using layer-by-layer processing. Each layer of the powder material is selectively melted using an energy beam such as a laser, electron, or particle beam.

Summary of the Invention

Problems to be Solved by the Invention

[0003] One problem in the operation of the system is maintaining the uniformity and quality of the powder dispensing layer.

Means for Solving the Problems

[0004] In a first aspect of the present disclosure, a 3D printing system for manufacturing a 3D object includes a build chamber, an overflow chamber adjacent to the build chamber, a motorized build plate, a powder coater including a vibration generator, a lateral movement mechanism connected to the powder coater, and a controller. The controller is configured to execute a process for removing powder accumulated from the surface of the powder coater according to the following steps: (1) operating the lateral movement mechanism to position the powder coater above a position laterally outside the build chamber; (2) operating the vibration generator to shake off the accumulated powder from the powder coater onto a position laterally outside the build chamber. The position laterally outside the build chamber may be above the overflow chamber.

[0005] In one implementation, the three-dimensional printing system further comprises a hopper and a beam system. The controller is configured to deposit a layer of selectively molten powder onto an upper surface according to the following steps: (1) positioning an electric construction plate having an upper surface adjacent to the construction plane to receive another powder layer; (2a) scanning a powder coater over the upper surface; (2b) simultaneously scanning and metering an unmolten powder layer onto the upper surface; (3) activating the beam system to selectively melt the metered layer. The designated upper surface is the upper surface of the construction plate (for selectively melting the first layer of powder) or the upper surface of the latest distribution layer of powder. The controller may be configured to deposit at least two layers of selectively molten powder while performing an accumulated powder removal process. The controller may be configured to deposit at least four, at least eight, at least 16, at least 32, or more layers of selectively molten powder while performing an accumulated powder removal process. The hopper may be located above the overflow chamber.

[0006] In another implementation, the powder coater is configured to scan along the scanning axis X. The powder coater has a principal axis along the transverse axis Y, which is perpendicular to the scanning axis X. A vibration generator is positioned or positioned in close proximity to one end of the powder coater with respect to the transverse axis Y. The vibration generator may be a motor connected to an eccentric weight. The motor's axis may be aligned with the scanning axis.

[0007] In yet another implementation, the vibration generator may include a vibrator such as a piezoelectric device and / or an ultrasonic transducer.

[0008] In a second aspect of the present disclosure, a method for manufacturing a three-dimensional object comprises the following steps: (A) Deposition of a selectively molten powder layer onto an upper surface. The upper surface is either the upper surface of a construction plate or the upper surface of a powder layer. The deposition step is to (1) position the upper surface close to the construction plane; (2a) scan the powder coater over the upper surface along the scanning axis; (2b) simultaneously scan and meter a layer of unmolten powder onto the upper surface; (3) activate a beam system to selectively melt the metered powder layer. (B) Repeat the deposition of the powder layer onto the construction plate. (C) After deposition of an N layer, where N is at least 1, remove any accumulated powder residue from the surface of the powder coater according to the following steps: (1) position the powder coater over a position that is laterally outside the construction plane; (2) activate a vibration generator to shake off any powder accumulated over the position outside the construction plane. Depending on the rate of powder accumulation on the powder coater, N may be at least 2, at least 4, at least 8, at least 16, at least 32, or a greater number.

[0009] In one implementation, the vibration generator may be a motor connected to an eccentric weight. The process of operating the vibration generator includes rotating the eccentric weight along an axis parallel to the scanning axis.

[0010] In a third aspect of the present disclosure, a three-dimensional printing system for manufacturing a three-dimensional object comprises a construction chamber, an overflow chamber adjacent to the construction chamber, an electric construction plate, a powder coater including a vibration generator, a powder hopper, a lateral movement mechanism, a beam system, and a controller. The controller is configured to perform the following: (1) position the upper surface close to the construction plane. (1) The top surface is either the top surface of the construction plate or the top surface of a previously deposited powder layer; (2) Activate the lateral movement mechanism and scan the powder coater over the construction plane; (3) Simultaneously with scanning, activate the powder coater to meter a layer of unmelted powder on the top surface; (4) Activate the beam system to selectively melt the metered powder layer; (5) Repeat (1) to (4) until a three-dimensional object is fabricated; (6) After metering and / or selectively melting the M layer, where M is at least 1, replenish the powder coater with powder using the powder hopper; (7) Move the powder coater to the overflow chamber and after metering and / or selectively melting the N layer, where N is at least 2, activate the vibration generator. M may be 2. N may be a positive non-zero integer that is a multiple of M. N may be at least 4, at least 8, at least 16, or a greater positive integer value. [Brief explanation of the drawing]

[0011] [Figure 1] Schematic side view of an embodiment of a three-dimensional printing system for fabricating three-dimensional objects. [Figure 2] Schematic plan view of several parts of an embodiment of a three-dimensional printing system comprising a build chamber, two overflow chambers, and a powder coater including a vibration generator. [Figure 3] Isometric view of an embodiment of a powder coater [Figure 3A] Detailed view from Figure 3, showing the outer casing portion which is transparent. [Figure 4] Flowchart illustrating an embodiment of a method for manufacturing a three-dimensional object. [Modes for carrying out the invention]

[0012] Figure 1 is a schematic side view of a three-dimensional printing system 2 for fabricating a three-dimensional object 4. In the description of system 2, mutually orthogonal axes X, Y, and Z may be used. Axes X and Y are transverse axes and are generally horizontal. Axe Z is a vertical axis and is generally aligned with a gravity reference. The term "generally" means that measurements such as comparisons of quantities, dimensions, or directions are by design and within manufacturing tolerances, but may not be accurate. Axe X is also called the scanning axis. Axe Y is also called the transverse axis.

[0013] System 2 comprises a construction chamber 6 including an electric construction plate 8. The electric construction plate 8 includes a vertical positioning mechanism 10 for adjusting the position of its upper surface 12. In reference to the upper surface 12, it is either the upper surface 12 of the construction plate 8 or the upper surface 12 of the previously distributed powder layer 14.

[0014] The overflow chamber 16 is located adjacent to the construction chamber 6. Although illustrated on one side of the construction chamber 6, the overflow chamber 16 may include two or more chambers and may be present on two, three, or all four sides of the construction chamber 6.

[0015] The powder coater 18 includes a lateral reporting and moving mechanism 20. The lateral moving mechanism is configured to scan the powder coater along the scanning axis X. Simultaneously with layering, the powder coater 18 is configured to weigh out layers of powder onto the top surface 12. The powder coater 18 typically holds enough powder to provide one or two powder layers 14. Therefore, the powder coater 18 needs to be replenished periodically.

[0016] The powder supply subsystem 22 supplies powder to the powder coater and "refills" the powder coater 18 with powder 14. The powder supply subsystem comprises a powder reservoir 24, a powder conveyor 26, and a hopper 28. The powder conveyor 26 may include a system of auger conveyors that rotates and conveys the powder from the powder reservoir 24 to the hopper 28. The hopper 28 is configured to distribute a large amount of powder 14 into the powder coater 18. In the illustrated embodiment, the powder hopper 28 is located above the overflow chamber 16.

[0017] When a new powder layer 14 is metered onto the upper surface 12, the beam system 30 is configured to selectively melt the powder layer and deposit it onto the object 4. The beam system 30 generates an energy beam which may include one or more of a radiation beam, an electron beam, or a particle beam.

[0018] In an exemplary embodiment, the beam system 30 generates and scans multiple laser radiation beams 32 that scan across a construction plane 34. The construction plane 34 defines the location of the new powder layer to be selectively melted.

[0019] In exemplary embodiments, powder 14 is a metal powder such as a titanium alloy, steel, nickel alloy, cobalt alloy, or aluminum alloy. In other embodiments, powder 14 is a polymer powder.

[0020] For metal powders, high-power lasers used to melt and dissolve the powder typically output at least 50 watts of radiant power. In various embodiments, the laser may output 500 watts or 1000 watts of power. For systems using polymer powders, the power level may be considerably lower.

[0021] The controller 36 is connected to and configured to operate a vertical positioning mechanism 10, a powder coater 18, a lateral movement mechanism 20, a powder supply subsystem 22, and a beam system 30. The controller 36 includes a processor connected to a computer-readable storage device. The computer-readable storage device includes a non-transitory or non-volatile storage medium that stores software instructions. When executed by the processor, the software instructions operate various parts of the system 2.

[0022] FIG. 2 is a schematic plan view of a portion of an embodiment of the system 2 including a build chamber 6, two overflow chambers 16, and a powder coater 18. The two overflow chambers 16 are at opposite ends of the build chamber 6 with respect to the scanning axis X. The powder coater 18 is shown disposed over one of the overflow chambers 16. During operation of the system 2, powder tends to accumulate on the surface of the powder coater 18. The accumulated powder sometimes randomly falls from the powder coater 18. When this occurs, defects can occur in the measured layer while the powder layer is being measured.

[0023] To address this issue, a vibrator 38 is incorporated into the powder coater 18. Concerns about the accumulated powder are addressed by positioning the powder coater 18 over a location outside of the build chamber and then operating the vibrator 38 at this location to shake the powder off. In the illustrated embodiment, the powder coater 18 is positioned over the overflow chamber 16 before operating the vibrator 38. By vibration, the powder falls into the overflow chamber 16.

[0024] In the illustrated embodiment, the front of the machine faces right (in the -Y direction). The vibrator 38 is disposed toward the rear side of the powder coater 18. The scanning axis X is from left to right and / or right to left when viewed from the front of the machine.

[0025] Figure 3 is an isometric view of an embodiment of the powder coater 18. The powder coater 18 has a principal axis parallel to the horizontal axis Y, an intermediate axis parallel to the scanning axis X, and a minor axis parallel to the vertical axis Z. The inlet slot 40 is positioned along the horizontal axis Y to receive powder dispensed from the hopper 28 when the powder coater is refilled with powder 14. The vibration generator 38 is located inside an opening 42 in the powder coater 18, which is positioned close to one end of the powder coater 18 with respect to the horizontal axis Y. A cover (not shown) is positioned over the opening 42 during use of the powder coater 18.

[0026] Figure 3A is a detail taken from Figure 3, showing a transparent portion of the outer casing 44 of the powder coater. In the illustrated embodiment, the vibration generator 38 includes a motor 46 connected to a semicircular eccentric weight. The motor 46 has a rotation axis 49 parallel to the scanning axis X. This version of the vibration generator 38 may also be referred to as a vibration motor 38.

[0027] In an exemplary embodiment, the vibration motor 38 can operate within an input voltage range of approximately 2 to 14 volts. Within this input voltage range, the rotational speed varies from approximately 20 Hz to approximately 130 Hz. Other vibration motors 38 may be used, and this is merely an example. Other motors may operate within different input voltages and / or different frequency ranges and may still be useful for this application. Further vibration generators 38, such as piezoelectric transducers and / or ultrasonic transducers, may be used.

[0028] Figure 4 is a flowchart illustrating an embodiment of method 50 for manufacturing a three-dimensional object 4 using a three-dimensional printing system 2. Method 50 shows the execution of software by a processor in the controller 36. However, the actual number of software steps is much greater than that shown in the flowchart.

[0029] Steps 52, 54, and 56 are steps for depositing a selectively molten powder layer onto the upper surface 12. According to 52, the motorized construction plate is activated to position the upper surface 12 close to the construction plane 34. According to 54, the powder coater 18 is scanned over the construction plane 34 along the scanning axis X. Simultaneously with the scanning, the powder coater 18 is activated to meter a powder layer 14 onto the upper surface 12. According to 56, the beam system 30 is activated to selectively melt the metered powder layer 14. As shown by the upper loop, steps 52-56 may be repeated M times based on the performance of the powder coater 18. In an exemplary embodiment, M = 2.

[0030] According to 58, the powder coater 18 is placed below the hopper 28. The hopper 28 then distributes the powder 14 into the inlet slot 40 and refills the powder coater 18. Steps 52-56 are repeated for the attachment of a selectively molten layer N of object 4, as shown by the central loop. Typically, N is a multiple of M. In an exemplary embodiment, N=12, and the powder coater 18 is refilled six times during the attachment of four selectively molten layers. During the formation of the 12 layers, powder may accumulate on the upper surface 45 of the powder coater (Figure 3).

[0031] According to 60, the powder coater 18 is placed above the overflow chamber 16. In one exemplary embodiment, the hopper 28 is also placed above the overflow chamber 16. According to 62, the vibration generator 38 is activated to shake the accumulated powder from the powder coater 18 into the overflow chamber 16. The process is then repeated back to step 52 for another N layers, and this process continues until the fabrication of object 4 is complete.

[0032] Generally, M can be 1 or greater. N may be equal to M, or it may be any non-zero positive integer that is a multiple of M. The choice of M is based on the performance of the powder coater 18, and the choice of N is based on the rate of powder accumulation on the outer surface of the powder coater 18.

[0033] The specific embodiments and applications described above are for illustrative purposes only and do not exclude modifications and variations that are included in the following claims.

[0034] Embodiment 1. A three-dimensional printing system for manufacturing three-dimensional objects, Construction chamber; An overflow chamber adjacent to the aforementioned construction chamber; Electric construction plate; Powder coater including a vibration generator; A lateral movement mechanism connected to the powder coater; and controller Equipped with, The aforementioned controller performs the following steps: Activate the lateral movement mechanism to position the powder coater above the outside of the construction chamber; and The vibration generator is activated, and the accumulated powder is shaken onto a position outside the construction chamber. The process is configured to remove the powder accumulated on the surface of the powder coater accordingly. A three-dimensional printing system. Embodiment 2. The controller further comprises a hopper and a beam system, and the controller performs the following steps: The motorized construction plate, having an upper surface adjacent to the construction plane, is positioned to receive another powder layer; The powder coater is scanned over the aforementioned upper surface; Simultaneously with the scanning, the unmelted powder layer on the upper surface is weighed; and The beam system is activated to selectively melt the measured layer. It is configured to selectively deposit a molten powder layer onto the upper surface accordingly. A three-dimensional printing system according to Embodiment 1, characterized in that... Embodiment 3. The tertiary printing system according to Embodiment 2, characterized in that the controller is configured to deposit at least two selectively molten powder layers during the execution of the accumulated powder removal process. Embodiment 4. The tertiary printing system according to Embodiment 2, characterized in that the controller is configured to deposit at least 10 selectively molten powder layers during the execution of the accumulated powder removal process. Embodiment 5. The three-dimensional printing system according to Embodiment 2, characterized in that the hopper is positioned above the overflow chamber. Embodiment 6. The three-dimensional printing system according to Embodiment 1, characterized in that the powder coater is configured to scan along a scanning axis, has a main axis along a horizontal axis perpendicular to the scanning axis, and the vibration generator is positioned close to one end of the powder coater with respect to the horizontal axis. Embodiment 7. The three-dimensional printing system according to Embodiment 6, characterized in that the vibration generator is a motor connected to an eccentric weight, and the shaft of the motor is aligned with the scanning shaft. Embodiment 8. The three-dimensional printing system according to Embodiment 6, characterized in that the vibration generator is a motor connected to an eccentric weight, and the shaft of the motor is aligned with the scanning shaft. Embodiment 9. The three-dimensional printing system according to Embodiment 1, characterized in that the position outside the construction chamber is determined by the overflow chamber. Embodiment 10. A method for manufacturing a three-dimensional object, A step of selectively adhering a molten powder layer onto an upper surface according to the following steps, wherein the upper surface is either the upper surface of the construction plate or the upper surface of the powder layer: The aforementioned upper surface is positioned in close proximity to the construction plane; Scan the powder coater over the upper surface along the scanning axis; Simultaneously with the scanning, the unmelted powder layer on the upper surface is weighed; The beam system is activated to selectively melt the metered powder layer. A process of repeatedly adhering the powder layer onto the construction plate; and After applying an N layer in which N is at least 1, the following steps are taken to remove any powder residue accumulated on the surface of the powder coater: The powder coater is placed on a position that is laterally outside the construction plane; The vibration generator is activated to shake the accumulated powder onto a position outside the construction plane. Methods that include... Embodiment 11. The method according to Embodiment 10, characterized in that N is at least 2. Embodiment 12. The method according to embodiment 10, characterized in that N is at least 10. Embodiment 13. The method according to Embodiment 10, characterized in that the vibration generator is a motor connected to an eccentric weight, and the step of operating the vibration generator includes the step of rotating the eccentric weight along an axis parallel to the scanning axis. Embodiment 14. The method according to Embodiment 10, characterized in that the location outside the construction plane includes an overflow chamber. Embodiment 15. A three-dimensional printing system for manufacturing three-dimensional objects, Construction chamber; An overflow chamber adjacent to the aforementioned construction chamber; Electric construction plate; Powder coater including a vibration generator; Powder hopper; Lateral movement mechanism; Beam systems; and controller Equipped with, The aforementioned controller, (1) Position the top surface, which is either the top surface of the construction plate or the top surface of the previously deposited powder layer, in close proximity to the construction plane; (2) Activate the lateral movement mechanism and scan the powder coater over the construction plane; (3) Simultaneously with the scanning, the powder coater is operated to weigh a layer of unmelted powder onto the upper surface; (4) Activate the beam system to selectively melt the metered powder layer; (5) Repeat steps (1) to (4) until a three-dimensional object is created; (6) After selectively melting the M layer in which M is at least 1, the powder coater is replenished with powder using the powder hopper; (7) Move the powder coater to the overflow chamber and selectively melt the N layer having at least 2 N, then activate the vibration generator. A three-dimensional printing system configured in such a way. Embodiment 16. The three-dimensional printing system according to embodiment 15, characterized in that M is equal to 2. Embodiment 17. The three-dimensional printing system according to embodiment 15, characterized in that N is at least 10. Embodiment 18. The three-dimensional printing system according to Embodiment 15, characterized in that the powder coater is configured to scan along a scanning axis, has a main axis along a horizontal axis perpendicular to the scanning axis, and the vibration generator is positioned at one end of the powder coater with respect to the horizontal axis. Embodiment 19. The three-dimensional printing system according to Embodiment 15, characterized in that the vibration generator is a motor connected to an eccentric weight, and the shaft of the motor is aligned with the scanning shaft.

Claims

1. A three-dimensional printing system for manufacturing three-dimensional objects, Construction chamber; An overflow chamber adjacent to the aforementioned construction chamber; Electric construction plate; Powder coater including a vibration generator; A lateral movement mechanism connected to the powder coater; and controller Equipped with, The controller performs a process to remove the powder accumulated on the surface of the powder coater according to the following steps: Activate the lateral movement mechanism to position the powder coater above the outside of the construction chamber; and The vibration generator is activated, and the accumulated powder is shaken onto a position outside the construction chamber. It is configured in such a way, The three-dimensional printing system further comprises a hopper and a beam system, and the controller performs the following steps: The motorized construction plate, having an upper surface adjacent to the construction plane, is positioned to receive another powder layer; The powder coater is scanned over the aforementioned upper surface; Simultaneously with the scanning, the unmelted powder layer on the upper surface is weighed; and The beam system is activated to selectively melt the measured layer. It is configured to selectively deposit a molten powder layer onto the upper surface accordingly. A three-dimensional printing system characterized by the following features.

2. The three-dimensional printing system according to claim 1, characterized in that the controller is configured to perform a removal process of the accumulated powder after at least two selectively molten powder layers have been attached.

3. The three-dimensional printing system according to claim 1 or 2, characterized in that the hopper is positioned above the overflow chamber.

4. The three-dimensional printing system according to any one of claims 1 to 3, characterized in that the powder coater is configured to scan along a scanning axis, has a main axis along a horizontal axis perpendicular to the scanning axis, and the vibration generator is positioned close to one end of the powder coater with respect to the horizontal axis.

5. The three-dimensional printing system according to claim 4, characterized in that the vibration generator is a motor connected to an eccentric weight, and the motor has a rotation axis parallel to the scanning axis.

6. The three-dimensional printing system according to any one of claims 1 to 5, characterized in that the position outside the construction chamber is determined by the overflow chamber.

7. A method for manufacturing a three-dimensional object, A step of selectively adhering a melted powder layer onto an upper surface according to the following steps, wherein the upper surface is either the upper surface of the construction plate or the upper surface of the powder layer: The aforementioned upper surface is positioned in close proximity to the construction plane; The powder coater is scanned over the upper surface along the scanning axis; Simultaneously with the scanning, the unmelted powder layer on the upper surface is weighed; The beam system is activated to selectively melt the metered powder layer. A process of repeatedly adhering the powder layer onto the construction plate; and After applying an N layer in which N is at least 1, the following steps are taken to remove the accumulated powder residue from the surface of the powder coater: The powder coater is placed on a position that is laterally outside the construction plane; The vibration generator is activated to shake the accumulated powder onto a position outside the construction plane. Methods that include...

8. The method according to claim 7, characterized in that N is at least 2.

9. The method according to claim 7 or 8, characterized in that the vibration generator is a motor connected to an eccentric weight, and the step of operating the vibration generator includes the step of rotating the eccentric weight along an axis parallel to the scanning axis.

10. The method according to any one of claims 7 to 9, characterized in that the position outside the construction plane includes an overflow chamber.

11. A three-dimensional printing system for manufacturing three-dimensional objects, Construction chamber; An overflow chamber adjacent to the aforementioned construction chamber; Electric construction plate; Powder coater including a vibration generator; Powder hopper; Lateral movement mechanism; Beam systems; and controller Equipped with, The aforementioned controller, (1) Position the top surface, which is either the top surface of the construction plate or the top surface of the previously deposited powder layer, in close proximity to the construction plane; (2) Activate the lateral movement mechanism and scan the powder coater over the construction plane; (3) Simultaneously with the scanning, the powder coater is operated to weigh a layer of unmelted powder onto the upper surface; (4) Activate the beam system to selectively melt the metered powder layer; (5) Repeat steps (1) to (4) until a three-dimensional object is created; (6) After selectively melting the M layer in which M is at least 1, the powder coater is replenished with powder using the powder hopper; (7) The powder coater is moved to the overflow chamber, and after selectively melting the N layer having at least 2 N, the vibration generator is activated. A three-dimensional printing system configured in such a way.

12. The three-dimensional printing system according to claim 11, characterized in that M is equal to 2 and / or N is at least 10.

13. The three-dimensional printing system according to claim 11 or 12, characterized in that the powder coater is configured to scan along a scanning axis and has a main axis along a horizontal axis perpendicular to the scanning axis, and the vibration generator is positioned at one end of the powder coater with respect to the horizontal axis.

14. The three-dimensional printing system according to claim 13, characterized in that the vibration generator is a motor connected to an eccentric weight, and the motor has a rotation axis parallel to the scanning axis.

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