Powder material laying device, powder material laying method, and program

Abstract

This powder material laying device is a device for laying a powder material in an additive manufacturing process, and comprises: a container for the powder material having an opening for dropping the powder material; a vibrating unit for applying vibration to the container; a moving unit for moving the container; a sensor for measuring a lamination height of a molding layer formed by the powder material dropped from the container; and a control unit for adjusting at least one of the movement speed or the vibration intensity of the container on the basis of a measured lamination height, which is the lamination height thus measured, and a target lamination height as a target.

Description

Powder material laying device, powder material laying method, and program

[0001] This application claims priority to Japanese Patent Application No. 2023-126576, filed on August 2, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses an example of the configuration of a powder bed three-dimensional printer that distributes modeling powder through a sheet screen by vibrating the sheet screen having a plurality of through-holes with an ultrasonic vibrator. The powder bed three-dimensional printer described in Patent Document 1 is said to be able to reduce the tendency of a recoater to distribute modeling powder unevenly due to local variations in vibration when no such changes are made by changing at least one of the size, shape, and distribution of the through-holes in the sheet screen.

[0003] Japan Special Table No. 2020-524095

[0004] It should be noted that Patent Document 1 describes that the ultrasonic transducer may include an electronic circuit incorporating temporary or periodic automatic tuning for adjusting at least one of the frequency and amplitude of the output vibration to achieve a desired level or consistency of the build powder flow rate through the sheet screen. However, Patent Document 1 does not specifically disclose how to perform the automatic tuning, such as how to adjust the frequency or amplitude of the output vibration to adjust the build powder flow rate.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a powder material laying device, a powder material laying method, and a program that can appropriately adjust the stack height of powder material.

[0006] In order to achieve the above-mentioned object, the powder material laying device of the present disclosure is an apparatus for laying powder material in an additive manufacturing process, and comprises: a container of powder material having an opening for dropping the powder material; a vibration unit that applies vibration to the container; a moving unit that moves the container; a sensor that measures the stack height of the modeling layer formed by the powder material dropped from the container; and a control unit that adjusts at least one of the moving speed or vibration strength of the container based on the measured stack height, which is the measured stack height, and a target stack height.

[0007] The powder material laying method disclosed herein is a method for laying powder material in an additive manufacturing process, and includes the steps of measuring the stack height of a modeling layer formed by the powder material dropped from a container using a powder material container having an opening for dropping the powder material, a vibration unit that imparts vibration to the container, and a moving unit that moves the container, and adjusting at least one of the moving speed of the container or the strength of the vibration based on the measured stack height, which is the measured stack height, and a target stack height.

[0008] The program disclosed herein is a program for laying powder material in an additive manufacturing process, and causes a computer to execute the following steps: using a container for powder material having an opening for dropping the powder material, a vibration unit that applies vibration to the container, and a movement unit that moves the container, to measure the stack height of a modeling layer formed by the powder material dropped from the container; and adjusting at least one of the movement speed or vibration strength of the container based on the measured stack height, which is the measured stack height, and a target stack height.

[0009] According to the powder material laying device, powder material laying method, and program disclosed herein, the stack height of the powder material can be appropriately adjusted.

[0010] FIG. 1 is a schematic configuration diagram schematically showing a configuration example of a powder material laying device according to an embodiment of the present disclosure; FIG. 2 is a front view of a powder container according to an embodiment of the present disclosure; FIG. 3 is a side view of a powder container according to an embodiment of the present disclosure; FIG. 4 is a control block diagram of a powder material laying device according to an embodiment of the present disclosure; FIG. 5 is a schematic diagram showing an example of a sieve according to an embodiment of the present disclosure; FIG. 6 is a flowchart showing the steps of a powder material laying method according to an embodiment of the present disclosure; FIG. 7 is a schematic block diagram showing the configuration of a computer according to an embodiment of the present disclosure;

[0011] A powder material laying device, a powder material laying method, and a program according to embodiments of the present disclosure will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram illustrating a configuration example of a powder material laying device 10 according to an embodiment of the present disclosure. FIG. 2 is a front view of a powder container 11 according to an embodiment of the present disclosure. FIG. 3 is a side view of a powder container 11 according to an embodiment of the present disclosure. FIG. 4 is a control block diagram of the powder material laying device 10 according to an embodiment of the present disclosure. FIG. 5 is a schematic diagram illustrating an example of a sieve 11b according to an embodiment of the present disclosure. FIG. 6 is a flowchart illustrating the steps of a powder material laying method according to an embodiment of the present disclosure. FIG. 7 is a schematic block diagram illustrating the configuration of a computer according to an embodiment of the present disclosure. Note that the same or corresponding components in each drawing are designated by the same reference numerals, and description thereof will be omitted as appropriate.

[0012] (Configuration of powder material laying device) Fig. 1 schematically shows a configuration example of a powder material laying device 10 according to an embodiment of the present disclosure, and an additive manufacturing device 1 including the powder material laying device 10. The additive manufacturing device 1 shown in Fig. 1 includes a laser three-dimensional modeling scanner 2 and the powder material laying device 10.

[0013] The additive manufacturing apparatus 1 is an apparatus for manufacturing a model 20 by stacking modeling layers 20L made of, for example, powder material 17 using an additive manufacturing (AM) process. The additive manufacturing process is a processing method for combining materials based on three-dimensional model data to materialize a model. The modeling layers 20L are material spread or applied in layers to form a surface. In this embodiment, the modeling layers 20L include a state in which the powder material 17 is laid down (powder layer state) and a state in which the layer is combined with a modeling laser beam. FIG. 1 also shows an example in which the model 20 is integrally formed with the workpiece 21 using a powder bed fusion process, which is one of the additive manufacturing processes, so as to fill a recess 21a in the workpiece 21. In this case, the modeling layer 20L is added with, for example, a curved modeling surface 21b and the previously deposited modeling layer 20L as the modeling surface. Powder Bed Fusion (PBF) is an additive manufacturing process that uses thermal energy to selectively melt and solidify a powder bed. The build surface is the area where material is added.

[0014] The 3D laser scanner 2 for fabrication uses laser sintering technology to irradiate laser light (laser light for fabrication) using one or more lasers, thereby repeatedly selectively melting or dissolving particles on the surface of the fabrication layer 20L, thereby forming a model 20 from the powder material 17. The 3D laser scanner 2 for fabrication controls the irradiation position of the laser light in three directions: X, Y, and Z.

[0015] The powder material laying device 10 is a device for laying a powder material 17 in an additive manufacturing process. The powder material laying device 10 includes a powder container (hereinafter also simply referred to as a container) 11, a vibration unit 12, a movement unit 13, and a sensor 14.

[0016] The powder container 11 is a container for the powder material 17, having an opening 11a for dropping the powder material 17. The powder container 11 drops the powder material 17 while being moved in the X direction by the moving unit 13, laying down a powder layer of a predetermined thickness (e.g., 50 μm per layer). FIGS. 2 and 3 show an example configuration of the powder container 11. Note that the correspondence between directions in FIGS. 1 to 3 is indicated by the X, Y, and Z axes. As shown in FIGS. 1 to 3, the powder container 11 has an opening 11a and a supply port 11c for the powder material 17. A sieve 11b is provided in the opening 11a. In addition, a vibration unit 12 and a vibration unit 16 for vibrating the powder container 11 are attached to the outer wall surface 11d of the powder container 11.

[0017] The vibration unit 12 is, for example, a piston-type air vibrator that applies vibrations to the powder container 11 due to reciprocating impact caused by the reciprocating motion of the piston, causing the powder material 17 in the powder container 11 to be ejected from the opening 11a through the sieve 11b and fall so that the powder material 17 is sprayed onto the modeling surface. The vibration unit 16 is, for example, an ultrasonic vibrator that generates vibrations to remove clogging from the sieve 11b, for example, when cleaning the sieve 11b. The "vibration unit" according to the present disclosure includes at least one of the vibration unit 12 and the vibration unit 16.

[0018] The sieve 11b has an opening W large enough to allow the powder material 17 to fall through when the sieve is vibrated. Alternatively, the sieve 11b has an opening W large enough to prevent the powder material 17 from falling through when the sieve is not vibrated. Alternatively, the sieve 11b has an opening W large enough to prevent the powder material 17 from falling through when the sieve is not vibrated, but to allow the powder material 17 to fall through when the sieve is vibrated. FIG. 5 shows an example of the opening W and the metal wire diameter d when the sieve 11b is a metal sieve mesh. For example, when the powder particle size of the powder material 17 is 10 to 45 μm, the opening W of the sieve 11b is set to a size equal to or several μm larger than the maximum size of the powder (for example, approximately 53 μm), so that multiple powder particles do not pass through the opening W at the same time, and the powder does not pass through when the sieve is not vibrated. In addition, in this embodiment, powder that has been passed through the sieve 11b in advance is used to prevent the sieve 11b from clogging with powder. That is, in this embodiment, when forming the object 20, the powder material 17 that has passed through the sieve 11b at least once is placed in the powder container 11.

[0019] The powder container 11 is supported by a moving part 13 via a jig 31 and moves in the direction indicated by the white arrow. The moving part 13 is a linear guide using, for example, a linear motor as a drive source.

[0020] The sensor 14 measures the stack height of the forming layer 20L formed by the powder material 17 dropped from the powder container 11. The sensor 14 is, for example, a thickness measurement sensor such as a laser displacement meter that uses laser light (measurement laser light) to measure the distance in the Z direction at multiple measurement points on the XY plane. The sensor 14 is supported by the moving unit 13 via a jig 31 and moves in the movement direction indicated by the white arrow. Under the control of the control unit 15, the sensor 14 measures the thickness, for example, after powder application and after laser light irradiation. The sensor 14 acquires measurements of, for example, the height (h1, h2, etc. in FIG. 1) (thickness) of one or multiple stacked forming layers 20L (in this embodiment, the height of one or multiple forming layers 20L is referred to as the stack height of the forming layer 20L) or the Z direction position of the surface of the forming layer 20L, and the height (h0 in FIG. 1) (thickness) of the workpiece 21 or the Z direction position of the surface of the workpiece 21.

[0021] The control unit 15 adjusts at least one of the movement speed and vibration intensity of the powder container 11 as needed based on the measured stack height (measured stack height) and the target stack height. The target stack height is the stack height that is designed to be achieved for the given number of stacks. For example, if the measured stack height is smaller than the target measurement height, the control unit 15 increases the laying amount by decreasing the movement speed or increasing the vibration intensity. Furthermore, if the measured stack height is larger than the target measurement height, the control unit 15 decreases the laying amount by increasing the movement speed or decreasing the vibration intensity. For example, the control unit 15 can simultaneously adjust the movement speed and the vibration intensity, or adjust only the movement speed or only the vibration intensity, depending on the deviation between the measured stack height and the target measurement height. Furthermore, the control unit 15 may adjust the movement speed and the vibration intensity for each laying operation or every predetermined number of times. Furthermore, the control unit 15 may adjust the movement speed and the vibration intensity for each laser light irradiation operation or every predetermined number of times. Note that "adjusting... as necessary" means, for example, making an adjustment if the difference between the measured stacking height and the target stacking height is not within a predetermined range, or making an adjustment if the adjustment is to be made after a predetermined number of laying operations or laser light irradiation operations. Also, for example, when making an adjustment after a plurality of laying operations or laser light irradiation operations, the control unit 15 may omit measuring the laying height or stacking height using the sensor 14 in the case of operations that do not require adjustment.

[0022] 4, the control unit 15 acquires the measurement results of the sensor 14 and controls the vibration strength (or frequency) of the vibration applying unit 12, the speed and position of the powder container 11 moved by the moving unit 13, and the position of the sensor 14 moved by the moving unit 13. The control unit 15 also controls the irradiation position of the laser beam from the 3D laser scanner for fabrication by transmitting and receiving predetermined control signals to and from the 3D laser scanner for fabrication. The control unit 15 also has the function of controlling the measurement of the stack height and the like by the sensor 14 and manually setting the moving speed and vibration strength, for example, according to input instructions from an operator.

[0023] (Operational Example of Powder Material Laying Device) An operational example of the powder material laying device 10 will be described with reference to FIG. 6 . In the example shown in FIG. 6 , first, for example, the powder material 17 is manually sorted in advance by passing it through a sieve 11b, and only the powder material 17 that has passed through is selected (step S10). Note that the sieve 11b provided in the powder container 11 may be used, or, for example, a separate powder container and sieve may be prepared and used for sorting. During sorting, the powder material 17 remaining in the powder container 11 is removed from the powder container 11 and set as unused material. Note that this operational example is intended to lay a modeling layer 20L having a thickness (e.g., 50 μm) suitable for laser sintering in a single laying operation.

[0024] Next, the powder material 17, which has been selected (picked) manually, for example, is stored in the powder container 11 (step S11).

[0025] Next, the amount of powder applied is adjusted, for example, manually (step S12). In step S12, the application status is first visually confirmed, and the application amount is adjusted by adjusting the vibration strength of the vibration unit 12. Furthermore, the powder container 11 is moved at a constant speed, the amount of powder applied is measured, and the vibration strength is readjusted.

[0026] Next, the control unit 15 measures the height of the workpiece 21 using the sensor 14 (step S13). This height of the workpiece 21 becomes the reference height before molding.

[0027] Next, the control unit 15 vibrates the vibration unit 12 at the set vibration intensity and moves the powder container 11 at the set moving speed to lay down the powder material 17 (step S14).

[0028] Next, the control unit 15 uses the sensor 14 to measure the powder application height (step S15).

[0029] Next, the control unit 15 transmits and receives predetermined control signals to and from the laser 3D modeling scanner 2, thereby irradiating the laid powder material 17 with laser light to form the modeling layer 20L (step S16).

[0030] Next, the control unit 15 uses the sensor 14 to measure the stack height (measured stack height) of the modeling layer 20L (step S17).

[0031] Next, the control unit 15 compares the measured stack height with the target stack height, and adjusts, as necessary, one or both of the moving speed and the vibration strength when laying the next layer (step S18).

[0032] Next, the control unit 15 determines whether a predetermined termination condition is met (step S19). The predetermined termination condition may be, for example, that all preset processes have been executed, that the operator has input an instruction to terminate the process, or that a predetermined malfunction has occurred. If the termination condition is met (step S19: YES), the control unit 15 terminates the process.

[0033] If the termination condition is not met (step S19: NO), the control unit 15 determines whether the number of stacks (after cleaning or replacement, if any) has reached a predetermined number or whether the difference between the measured stack height and the target stack height has reached a predetermined threshold value (step S20). If the number of stacks has reached the predetermined number or the difference between the measured stack height and the target stack height has reached a predetermined threshold value (step S20: YES), the control unit 15 notifies the user that cleaning or replacement of the sieve 11b is necessary. At this point, the operator manually cleans or replaces the sieve 11b (step S21). When cleaning or replacing the sieve 11b, for example, the powder material 17 is temporarily removed from the powder container 11, and the sieve 11b is cleaned by using an air gun or the like to blow air from above and below the storage container 11, or the sieve 11b is replaced. Alternatively, the powder material 17 is not removed from the powder container 11, and the vibration unit 16 vibrates the powder container 11, causing a small amount of powder material 17 to fall through the sieve 11b, thereby cleaning the sieve 11b. Note that if the powder material 17 is removed from the powder container 11 in step S21, the powder material 17 is stored in the powder container 11, and the process proceeds to the next step. If the number of stacks has not reached the predetermined number and the difference between the measured stack height and the target stack height is not equal to or greater than the predetermined threshold (step S20: NO), or if cleaning or replacement has been performed (step S21), the process returns to step S14, and the processes from step S14 onward are executed again.

[0034] (Functions and Effects) In this embodiment, by vibrating a powder container equipped with a sieve (mesh) using a vibration unit (vibrator), the amount of powder supplied can be made uniform, making it possible to form a uniform powder layer along, for example, a curved surface. This also eliminates the need to provide a separate blade or other tool to flatten the surface of the powder layer. Furthermore, feedback control of the amount of powder applied allows for the creation of a design model.

[0035] As described above, according to this embodiment, the stack height of the forming layer 20L formed by the powder material 17 dropped from the powder container 11 is measured by the sensor 14, and at least one of the movement speed of the powder container 11 or the vibration strength of the vibration unit 12 is adjusted based on the measured stack height, which is the stack height measured by the control unit 15, and the target stack height, so that the stack height of the powder material can be appropriately adjusted.

[0036] (Modifications) Although the embodiments of the present disclosure have been described above with reference to the drawings, the specific configurations are not limited to the above-described embodiments, and also include design modifications within the scope of the gist of the present disclosure.

[0037] <Computer Configuration> Figure 7 is a schematic block diagram showing the configuration of a computer according to the embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The control unit 15 described above is implemented in the computer 90. The operations of each of the processing units described above are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-described processing in accordance with the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to each of the storage units described above in accordance with the program.

[0038] The program may be for realizing some of the functions to be performed by the computer 90. For example, the program may be combined with other programs already stored in storage or implemented in other devices to perform the functions. In other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0039] Examples of storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of computer 90, or an external medium connected to computer 90 via interface 94 or a communication line. Furthermore, if this program is distributed to computer 90 via a communication line, computer 90 that receives the program may load the program into main memory 92 and execute the above-described processing. In at least one embodiment, storage 93 is a non-transitory tangible storage medium.

[0040] <Additional Notes> The powder material laying device 10 described in the above embodiment can be understood, for example, as follows.

[0041] (1) A powder material laying device 10 according to a first aspect is an apparatus for laying powder material 17 in an additive manufacturing process, and includes a container (powder container 11) for the powder material 17 having an opening 11a for dropping the powder material 17, a vibration unit 12 for applying vibrations to the container, a moving unit 13 for moving the container, a sensor 14 for measuring the stack height of a modeling layer 20L formed by the powder material 17 dropped from the container, and a control unit 15 for adjusting at least one of the moving speed of the container or the strength of the vibration based on a measured stack height, which is the measured stack height, and a target stack height. According to this aspect and each of the following aspects, the stack height of the powder material can be appropriately adjusted.

[0042] (2) The powder material laying device 10 according to the second aspect is the powder material laying device 10 according to (1), in which the opening 11a is provided with a sieve 11b having a mesh size (W) that allows the powder material 17 to fall in a predetermined vibration state. According to this aspect, the powder material 17 can be caused to fall by being vibrated.

[0043] (3) A powder material laying device 10 according to a third aspect is the powder material laying device 10 of (2), in which the sieve has a mesh size that prevents the powder material 17 from falling without vibration. According to this aspect, the powder material can be prevented from falling by not applying vibration, so there is no need to provide a special mechanism to stop the falling.

[0044] (4) A fourth aspect of the powder material application device 10 is the powder material application device 10 of (2) or (3), in which the sieve 11b is cleaned or replaced every predetermined number of stacks or when the difference between the measured stack height and the target stack height is equal to or greater than a predetermined threshold. According to this aspect, the effects of clogging of the sieve can be suppressed.

[0045] (5) A fifth aspect of the powder material laying device 10 is the powder material laying device 10 of (2) or (3), in which the powder material 17 that has passed through the sieve 11b at least once is placed in the container when forming the modeling layer 20L. This aspect can reduce the effects of, for example, powder material with poor fluidity or foreign matter of a size that can be separated by a sieve.

[0046] According to the above-described aspect, the stack height of the powder material can be appropriately adjusted.

[0047] DESCRIPTION OF SYMBOLS 1...Layered manufacturing device 2...3D laser scanner for manufacturing 10...Powder material laying device 11...Powder container (container) 11a...Opening 11b...Sieve 12, 16...Vibration unit 13...Moving unit 14...Sensor 15...Control unit 17...Powder material 20...Model 20L...Modeling layer W...Opening h1, h2...Stacking height

Claims

1. An apparatus for laying powder material in an additive manufacturing process, comprising: a container of powder material having an opening for dropping the powder material; a vibration unit for imparting vibration to the container; a moving unit for moving the container; a sensor for measuring the stack height of a modeling layer formed by the powder material dropped from the container; and a control unit for adjusting at least one of the moving speed or vibration strength of the container based on a measured stack height, which is the measured stack height, and a target stack height.

2. A powder material laying device as described in claim 1, wherein the opening is provided with a sieve having an opening size that allows the powder material to fall under a specified vibration state.

3. A powder material laying device as described in claim 2, wherein the sieve openings are large enough to prevent the powder material from falling without vibration.

4. A powder material laying device as described in claim 2 or claim 3, wherein the sieve is cleaned or replaced after every predetermined number of stacks or when the difference between the measured stack height and the target stack height becomes equal to or exceeds a predetermined threshold value.

5. A powder material laying device as described in claim 2 or claim 3, wherein when forming the modeling layer, the powder material that has passed through the sieve at least once is placed in the container.

6. A method for laying powder material in an additive manufacturing process, comprising the steps of: measuring the stack height of a modeling layer formed by the powder material dropped from the container using a container of powder material having an opening for dropping the powder material, a vibration unit for applying vibration to the container, and a moving unit for moving the container; and adjusting at least one of the moving speed or vibration strength of the container based on a measured stack height, which is the measured stack height, and a target stack height.

7. A program for laying powder material in an additive manufacturing process, comprising: a container of powder material having an opening for dropping the powder material; a vibration unit for applying vibration to the container; and a moving unit for moving the container; a step of measuring the stack height of a modeling layer formed by the powder material dropped from the container; and a step of adjusting at least one of the moving speed or vibration strength of the container based on a measured stack height, which is the measured stack height, and a target stack height.

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