JP2021120209A - Three-dimensional object molding device - Google Patents

Abstract

To provide a powder-bed type three-dimensional object molding device that can easily inspect the melting state of material powder and the stacking state of the melted and bonded molding materials during molding.SOLUTION: A sample forming section 7 is provided at the side of a three-dimensional object molding section 4. A sample box 10 is removably placed inside the sample forming section 7, and is filled with material powder. A laser irradiator 14 is placed above the three-dimensional object molding section and the sample forming section, and moves in the three-dimensional direction. A sealed room 15 filled with inert gas seals the three-dimensional object molding section, a recoater 5, the sample forming section, and the laser irradiator. A partition wall 16 is provided inside the sealed room to air-tightly separate the three-dimensional object molding section from the sample forming section. A first shutter 18 is provided in the sealed room, and a second shutter 20 is provided in the partition wall and is closed when the first shutter is opened. A mechanism 22 is provided to remove the sample inside the sample forming section and transport it to a radiation inspection device 21.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to a powder bed type three-dimensional object modeling apparatus.

A three-dimensional object modeling device generally called a 3D printer is used to manufacture a three-dimensional object made of resin or metal. In particular, a 3D printer using a powder bed fusion bonding method in which flatly spread resin or metal powder is melted and bonded by a laser beam and laminated is adopted in various fields of the manufacturing industry.

In a 3D printer using this powder bed fusion bonding method, molten metal is stacked in multiple layers, so that fusion failure, penetration failure, or voids are likely to occur between the layers. In order to eliminate these, it is necessary to appropriately control the heating temperature by the laser beam and the supply amount of the metal powder.

In order to make a three-dimensional object have an intended shape, it is necessary to make the state of a metal molten pool called a melt pool an appropriate size and shape. That is, if the molten pool is too small, the molten metal required for the three-dimensional object is insufficient and the three-dimensional object is defective, and if the molten pool is too large, dripping occurs and extra protrusions and irregularities are generated on the three-dimensional object. Therefore, it is necessary to appropriately control the supply amount of the metal powder, the output of the laser beam, and the moving speed according to the shape and dimensions of the three-dimensional object.

Conventionally, as a three-dimensional object modeling device for metal products, as shown in Patent Document 1, a device that inspects a three-dimensional object during or after completion by providing a radiation CT or a radiation fluoroscopy device has been proposed.

JP-A-2019-104981

The device of Patent Document 1 (here, a three-dimensional object is referred to as a modeled object) is called a powder bed method or a powder bed melt-bonding method, and after spraying a thin resin or metal powder on a flat stage. , A part of the sprayed resin or metal is melted and bonded by a laser beam to create a predetermined shape.

By repeating this spraying and melting / bonding, a modeled object is modeled. In this conventional technique, an X-ray generator is arranged above the stage and an X-ray detector is arranged below the stage to detect the amount of X-ray transmission. The following drawbacks can be considered in this conventional technique.
(1) A region that is determined to be smaller than the design thickness by irradiating the modeled object with X-rays and detecting the amount of transmission with an X-ray detector is defined as a void-existing area. However, when the thickness of the modeled object increases, X-rays are emitted. The accuracy of the transmission data is gradually lost. Further, in order to make the amount of X-ray transmission uniform, it is almost impossible to change the output of the X-ray generator every time to deal with the thickness of the modeled object, the material, the size of the powder, and the like.
(2) Distance from the X-ray focus (X-ray generator) to the X-ray image receiving surface (X-ray detector) The FDD (Focus To Detector Distance) is constant, and X-rays are emitted in a radial pattern. The field of view becomes narrower as the height of the X-ray increases.
(3) Since the modeled object and its surroundings are irradiated with X-rays in an environment of metal powder, scattered rays are generated as noise in many directions, and the accuracy of the X-ray transmission amount data is lacking.
(4) The X-ray detector on the stage and the X-ray generator on the vertical side are fixed, and since there is a model in the radial beam from the X-ray source, the image can be taken from only one direction. In addition, even if a plurality of X-ray generators and X-ray detectors are provided and relatively scanned, the outer periphery of the modeled object remains filled with unmelted / bonded powder. A clear image cannot be obtained for a part covered with metal powder such as a surface.

By the way, in the powder bed method, in order to prevent a dust explosion and oxidation of a modeled object, the entire apparatus is housed in a closed room, and modeling is performed in an atmosphere of an inert gas such as nitrogen gas or argon gas. In the device of Patent Document 1, the X-ray generator and the X-ray detector are arranged in the closed chamber, but the distance between the modeled object and the X-ray focal point becomes large, and the details of the modeled object, particularly the state of the molten pool. Cannot be enlarged and displayed. Even if the modeled object is taken out during modeling and inspected, it takes about 10 minutes to refill the exhausted inert gas into the closed chamber, depending on the scale of the device, and the modeling work is required. It will be interrupted for a long time.

This embodiment has been proposed to solve the above-mentioned problems of the prior art. An object of the present embodiment is to provide a powder bed type three-dimensional object modeling apparatus capable of easily inspecting a molten state of a material powder and a laminated state of a molten / bonded modeling material at the time of modeling.

The powder bed type three-dimensional object modeling apparatus according to the embodiment of the present invention has the following configuration.
(1) A base installed on the floor surface and a table that is provided so as to be able to move up and down with respect to the base and on which a three-dimensional object to be modeled is placed.
(2) A frame portion that is arranged around the table and the table moves up and down inside the table.
(3) An upper surface opening type three-dimensional object modeling portion formed by the table and the frame portion.
(4) A recorder that is arranged above the three-dimensional object modeling portion and supplies a powder material having a predetermined thickness into the three-dimensional object modeling portion.
(5) A powder storage unit that supplies a powder material to the three-dimensional object modeling unit.
(6) A sample forming portion provided on the side of the three-dimensional object modeling portion.
(7) A laser irradiator that is arranged above the three-dimensional object modeling portion and the sample forming portion and moves in at least three-dimensional directions with respect to the table surface.
(8) A closed chamber in which the three-dimensional object modeling portion, the recorder, the sample forming portion, and the laser irradiator are sealed and filled with an inert gas.
(9) A partition wall provided in the closed chamber that airtightly partitions the three-dimensional object modeling portion and the sample forming portion.
(10) A first shutter provided in the closed chamber and capable of taking the sample in and out of the sample forming portion.
(11) A second shutter provided on the partition wall and closed when the first shutter is opened.

In the embodiment, the configuration can be as follows.
(1) It has a radiation inspection device arranged in the vicinity of the closed chamber and a mechanism for taking out the sample in the sample forming portion and transporting the sample to the radiation inspection device.
(2) The sample forming unit can form a plurality of the samples.
(3) The sample forming portion has a sample box filled with material powder inside and a holding mechanism thereof.
(4) The sample box has a nozzle for supplying the material powder in synchronization with the supply of the material powder to the three-dimensional object modeling portion by the recorder.
(5) The transport mechanism is an articulated robot.
(6) The radiation inspection device is a fluoroscopic image display device that converts the output from the radiation detector into image data and displays it.
(7) The radiation inspection apparatus is a radiation CT that reconstructs the output from the radiation detector and outputs a cross-sectional image of the three-dimensional object.

The perspective view of the three-dimensional object modeling apparatus of 1st Embodiment. The perspective view which shows the sample box and the holding mechanism thereof in 1st Embodiment. The functional block diagram which shows the control part of 1st Embodiment. The cross-sectional view which shows the modification of the sample forming part. The perspective view which shows the other modification of the sample forming part.

[1. First Embodiment]
[1-1. Configuration of Embodiment]
[1-1-1. Three-dimensional object modeling device]
As shown in the perspective view of FIG. 1, the three-dimensional object modeling device of the first embodiment is provided with a base 1 installed on the floor surface and a three-dimensional object to be modeled by being vertically movable with respect to the base 1. A table 2 on which the table is placed is provided. A frame portion 3 arranged around the table 2 is fixed to the base 1. Inside the frame portion 3, a table 2 and a drive mechanism (not shown) for intermittently raising and lowering the table 2 at intervals corresponding to the spray thickness of the material powder are provided. As the drive mechanism, for example, a cylinder, a linear motor, a screw rod, a rack & pinion, or the like with a guide can be used.

On the upper surface of the table 2, an upper surface opening type three-dimensional object modeling portion 4 surrounded by the table 2 and the frame portion 3 is formed. The recorder 5 is arranged above the three-dimensional object modeling unit 4. The recorder 5 is a member for laying a powder material of a predetermined thickness in the three-dimensional object modeling portion 4, is provided with a drive mechanism (not shown), and reciprocates in the left-right direction in the drawing along the upper edge of the frame portion 3. .. The recorder 5 is an elongated box-shaped member having an open upper surface, the lower portion of which functions as a stage that slides along the upper surface of the frame portion 3, and the inside of the box supplies powder material to the three-dimensional object modeling portion 4. It is a powder storage unit 6. As the material powder, in the case of a metal type, iron powder, stainless steel powder, titanium alloy and the like can be used. The size of the metal powder is preferably about 20 μm to 45 μm. Various resin powders can be used instead of the metal powder.

A sample forming portion 7 is provided on the side of the three-dimensional object modeling portion 4 on the upper part of the base 1. The sample forming portion 7 includes a support plate 8 arranged parallel to and horizontally with the recorder 5. The support plate 8 is fixed to the upper part of the base 1 at substantially the same height as the upper edge of the frame portion 3. A plurality of holding mechanisms 9 are provided on the support plate 8 at regular intervals, and the sample box 10 is detachably fixed to each holding mechanism 9. As shown in the enlarged perspective view of FIG. 2, the sample box 10 is a square box-shaped member having an open upper surface. The sample box 10 is preferably made of carbon fiber reinforced plastic that easily transmits radiation and can withstand high temperatures when the material powder is melted by a laser, but may be made of other materials. The holding mechanism 9 is composed of, for example, a pair of screw plates 11 that rise from the support plate 8 at regular intervals, and fixing bolts 12 that are screwed into each screw plate 11. The sample box 10 is fixed to the support plate 8 by arranging the sample box 10 between the pair of fixing bolts 12 and tightening the fixing bolts 12. As the holding mechanism 9, the sample box 10 can be gripped by the force of a motor, a cylinder, or an electromagnetic plunger.

Above the sample box 10 in the sample forming unit 7, a powder supply nozzle 13 for filling the material powder in each sample box 10 is arranged. The powder supply nozzle 13 is moved along the arrangement direction of each sample box 10 by a drive mechanism (not shown), and the material powder is sprayed into the sample box 10 with a constant thickness while stopped above each sample box 10. do. The material powder is sprayed by the powder supply nozzle 13 in synchronization with the supply of the material powder to the three-dimensional object modeling unit 4 by the recoater 5, and the material powder of the same thickness is always provided in the sample box 10 and the three-dimensional object modeling unit 4. Layers are formed.

The laser irradiator 14 is arranged above the three-dimensional object modeling unit 4. The laser irradiator 14 moves in at least three-dimensional directions with respect to the surface of the table 2 by a drive mechanism (not shown). That is, the laser irradiator 14 corresponds to the modeling position of the three-dimensional object in the three-dimensional object modeling unit 4 and the sample modeling position in the sample forming unit 7 (specifically, the range inside each sample box 10). Move left and right and up and down. Therefore, as the drive mechanism, an articulated robot, a link arm that expands and contracts in the horizontal direction is attached to the lower end of a vertical rotating shaft that moves up and down, and a laser irradiator 14 is fixed to the tip of the link arm.

The three-dimensional object modeling unit 4, the recorder 5, the sample forming unit 7, and the laser irradiator 14 are arranged in a closed chamber 15 filled with an inert gas. As the inert gas, nitrogen gas can be generally used to prevent dust explosion due to powder oxidation and oxidation of three-dimensional objects, but if the material powder contains titanium, it will generate heat and ignite due to argon. Use argon gas to prevent. In the closed chamber 15, a partition wall 16 for airtightly partitioning the closed chamber 15 is provided. The partition wall 16 divides the inside of the closed chamber 15 into a three-dimensional object modeling portion 4 in which the recoater 5 and the laser irradiator 14 are arranged, and a sample forming portion 7 in which the sample box 10 is arranged. The inert gas is filled in each of the partitioned three-dimensional object modeling portion 4 and the sample forming portion 7.

An outlet 17 for a sample and a first shutter 18 for opening and closing the outlet 17 are provided on the outer wall surface of the closed chamber 15 on the side of the sample forming portion 7. When the first shutter 18 is opened, the outlet 17 is opened, and the transport mechanism (the tip of the articulated robot 22 in the illustrated embodiment) is inserted into the outlet 17, so that the sample box is referred to the sample forming portion 7. 10 can be taken in and out.

The partition wall 16 is provided with a passage port 19 for the laser irradiator 14 to enter the sample forming portion 7, and a second shutter 20 for opening and closing the passage port 19. That is, when the second shutter 20 is opened, the passage port 19 is opened, and the articulated robot 22 or the link arm supporting the laser irradiator 14 is allowed to enter the inside of the passage port 19, thereby causing the second shutter 20 to enter the sample forming unit 7. Allows sample modeling work.

When the first shutter 18 is opened and the sample outlet 17 is open, the second shutter 20 is closed, and the sealing property of the three-dimensional object modeling portion 4 separated by the partition wall 16 is ensured. The structure of the first shutter 18 and the second shutter 20 is not limited as long as the closed chamber 15 and the partition wall 16 can be hermetically sealed. In the present embodiment, the first shutter 18 and the second shutter 20 move in the vertical direction along the surfaces of the closed chamber 15 and the partition wall 16 to open and close the outlet 17 and the passage port 19.

[1-1-2. Sample transfer mechanism (articulated robot 22)]
In the vicinity of the closed chamber 15, a radiation inspection device 21 for acquiring a fluoroscopic image of a sample and a sample transfer mechanism for taking out a sample box 10 in a sample forming unit 7 and transporting the sample box 10 to the radiation inspection device 21 are provided. As the sample transfer mechanism, an articulated robot 22 having a grip portion 23 at the tip is used. The grip portion 23 enters the sample forming portion 7 from the sample outlet 17 provided on the wall surface of the closed chamber 15 and carries the sample box 10 to the outside of the closed chamber 15. At this time, the articulated robot 22 has a function of rotating the fixing bolt 12 by the grip portion 23 and releasing the fixing of the sample box 10 by the holding mechanism 9. The articulated robot 22 moves the grip portion 23 toward the radiation inspection device 21, and places the sample box 10 on the turntable 24 provided in the radiation inspection device 21. When an electric type holding mechanism 9 is used, instead of releasing the holding mechanism 9 by the articulated robot 22, when the sample box is taken out, the holding mechanism 9 is opened by an electric signal.

[1-1-3. Radiation inspection device 21]
The radiation inspection device 21 has a turntable 24 supported by an elevating mechanism 25, a radiation generator 21a and a radiation detector 21b arranged across the turntable 24. The turntable 24 is moved up and down by the elevating mechanism 25, and is supported by an XY mechanism (not shown) to move in the horizontal direction. The radiation generator 21a and the radiation detector 21b are supported by the elevating mechanism 25 so as to be independently moved up and down, and are supported by the rotating mechanism 26 so as to rotate around the turntable 24 together with the elevating mechanism 25. The radiation detector 21b detects the radiation transmitted through the shaped three-dimensional object and outputs it as electronic data. For example, a radiation image fluorescence multiplying tube (image intensifier) and a camera for photographing the radiation, MCP. (Micro channel plate), a camera that captures it, and an FPD (flat panel detector) can be used. Here, the camera may be a high speed camera.

The radiation inspection device 21 is provided with a reconstruction unit 211 that converts transmission data, which is output data from the radiation detector 21b, into a CT image, and a display unit 212 that displays the CT image obtained by the reconstruction unit 211. Instead of the CT image, the transparent data may be projected on the display unit 212 as a still image or a moving image.

[1-1-4. Control unit 30]
As shown in FIG. 3, the three-dimensional object modeling apparatus is provided with a control unit 30 that controls each mechanism. That is, a modeling device control unit 31, a transport mechanism control unit 32, and a radiation inspection device control unit 33 are provided. The modeling device control unit 31 includes a table control unit 311, a recoater control unit 312, a laser irradiator control unit 313, a first shutter and a second shutter control unit 314, and a powder supply nozzle control unit 315. The transport mechanism control unit 32 includes an articulated robot control unit 321 and a sample box holding mechanism control unit 322. The radiation inspection device control unit 33 has a scan control unit 331 positioning control unit 332.

The table control unit 311 controls the elevating mechanism of the table 2 by lowering the table 2 according to the height of the three-dimensional object formed when the material powder is melted layer by layer to form a three-dimensional object. The recorder control unit 312 controls the movement of the recorder 5 and the supply amount and timing of the material powder from the powder storage unit 6 to the three-dimensional object modeling unit 4. The laser irradiator control unit 313 controls the moving position, speed, laser beam output, and the like of the laser irradiator 14. The first shutter and the second shutter control unit 314 control the opening / closing of the first shutter 18 and the second shutter 20 when the sample box 10 is taken in and out, and the opening / closing control of the second shutter 20 when the laser irradiator 14 is moved. I do. The powder supply nozzle control unit 315 controls the supply amount of the material powder, the supply timing, the moving position of the nozzle, and the like for each sample box 10.

The articulated robot control unit 321 controls the moving position and timing of the articulated robot 22 when the sample box 10 is taken out from the closed chamber 15 and placed on the turntable 24 of the radiation inspection device 21. The sample box holding mechanism control unit 322 controls the sample box 10 to be fixed or opened in the sample forming unit 7. When the articulated robot 22 releases the fixing of the sample box 10 by the holding mechanism 9 by turning the fixing bolt 12, the articulated robot control unit 321 can also serve as the sample box holding mechanism control unit 322. ..

The scan control unit 331 controls the imaging start timing by the radiation generator 21a, the radiation output, the radiation beam angle, the magnification, the processing of the transmission data by the reconstruction unit 211, the display form of the image displayed on the display unit 212, and the like. The positioning control unit 332 controls the rotation mechanism 26 of the turntable 24, the radiation generator 21a and the radiation detector 21b, and the elevating mechanism 25 to control their positions, angles, moving speeds, and the like.

[1-2. Action of embodiment]
In order to form a three-dimensional object in the present embodiment, the first shutter 18 is closed to make the inside of the closed chamber 15 airtight, and the inside thereof is filled with an inert gas. At this time, the second shutter 20 is opened to open the passage port 19, so that both the three-dimensional object modeling portion 4 and the sample forming portion 7 have an inert gas atmosphere, and the laser irradiator 14 is three-dimensionalized through the passage port 19. Allows movement between the modeling section 4 and the sample forming section 7.

Next, by moving the recorder 5 above the table 2 surrounded by the frame portion 3, one layer of material powder is supplied from the powder storage portion 6 provided in the recorder 5 to the surface of the table 2. In this case, as the recorder 5 moves along the upper edge of the frame portion 3, the excess material powder supplied on the table 2 is scraped off, and a predetermined amount of the material powder layer is formed on the table 2. It is formed. At the same time, the material powder is sequentially supplied from the powder supply nozzle 13 to the inside of each sample box 10, and a material powder layer having the same thickness as that on the table 2 is formed on the bottom of each sample box 10.

To check the filling state of the supplied material powder before modeling the three-dimensional object, close the second shutter 20 with the material powder supplied in the sample box 10, open the first shutter 18, and take out the outlet. Open 17. The grip portion 23 of the articulated robot 22 is inserted into the open outlet 17, the fixing bolt 12 of the holding mechanism 9 is loosened, the sample box 10 is lifted by the grip portion 23, and the sample box 10 is taken out of the closed chamber 15. The taken-out sample box 10 is conveyed to the radiation inspection device 21 by the articulated robot 22 and set on the turntable 24. Immediately after taking out the sample box 10, the first shutter 18 is closed, the outlet 17 is closed, and the closed chamber 15 is sealed. After sealing, the second shutter 20 is opened to allow the three-dimensional object modeling portion 4 and the sample forming portion 7 to communicate with each other to create an inert gas atmosphere in the sample forming portion 7, and the passage port 19 is opened to open the laser irradiator 14. It can be moved to the sample forming portion 7 side.

After supplying one layer of material powder into the three-dimensional object modeling unit 4 and the sample box 10, the material powder on the table 2 is irradiated with a laser beam while moving the laser irradiator 14 at a pre-programmed position and speed. By doing so, the material powder is melted on the table 2. Since the material powder melted on the table 2 is cooled and solidified as the laser irradiator 14 moves, a three-dimensional object for one layer of the powder material corresponding to the trajectory of the laser irradiator 14 is formed on the table 2. ..

Following the irradiation of the laser beam to the three-dimensional object modeling portion 4, the laser irradiator 14 is moved from the passage port 19 to the upper part of the sample box 10 with respect to the material powder for one layer supplied to the bottom of the sample box 10. , The laser beam is irradiated with the same output and moving speed as the three-dimensional object modeling unit 4. The shape of the sample to be modeled in the sample box 10 is arbitrary, but it is desirable that the shape of the sample to be modeled is close to the shape of the part requiring inspection. After the irradiation of the laser beam to the material powder in the three-dimensional object modeling unit 4 and the sample box 10 is completed, the laser irradiator 14 is returned to the three-dimensional object modeling unit 4 side.

After the first layer of the material powder is melted and solidified in the three-dimensional object modeling unit 4 and the sample box 10, the table 2 is lowered by the height of one layer of the material powder, and the three-dimensional object modeling unit 4 is again used by the recorder 5. A second layer of material powder is supplied inside. At the same time, the material powder of the second layer is supplied from the powder supply nozzle 13 into the sample box 10. After that, the material powder is melted by the laser irradiator 14, and the melted material is laminated in multiple layers on the bottom of the table 2 and the sample box 10 by repeating the supply, melting and solidification of the material powder. Then, a three-dimensional sample and a three-dimensional object to be modeled are modeled.

In the present embodiment in which a plurality of sample boxes 10 are provided, the first sample box 10 is taken out without irradiating the laser beam, subjected to a fluoroscopic inspection with a radiation detector 21b, and the second and subsequent sample boxes. For No. 10, the sample box 10 is taken out and a radiation inspection is performed every time the number of laminated materials reaches a certain number of times. By taking out the sample box 10 and inspecting it at any different stage of the modeling operation of the three-dimensional object in this way, the molten state of the material powder (particularly the state of the molten pool) and the gas bubbles inside the three-dimensional object (gas pores). ) Can be confirmed. Further, since the unmelted material powder remains around the three-dimensional object formed in the sample box 10 without being irradiated with the laser beam, it is possible to know the state of the unmelted material powder during the modeling process. can.

The sample box 10 of each stage taken out from the closed chamber 15 is placed on the turntable 24 of the radiation detection device by the articulated robot 22, and is irradiated with the radiation from the radiation generator 21a. At that time, the sample box 10 is positioned by controlling the XY mechanism and the elevating mechanism 25 by the positioning control unit 332 so that the sample placed on the turntable 24 comes to a predetermined position.

The radiation transmitted through the sample box 10 and the sample inside the sample box and the surrounding material powder is converted into electronic data by the radiation detector 21b. The transmitted data from the radiation detector 21b is displayed on the display unit 212 in the case of a still image or a moving image. When obtaining a CT image, the rotation mechanism 26 is used to rotate the radiation generator 21a and the radiation detector 21b around the turntable 24, and the obtained fluoroscopic image is converted by the reconstruction unit 211 and displayed. Output to 212.

The operations and processes of each unit as described above are executed by the modeling device control unit 31, the transport mechanism control unit 32, and the radiation inspection device control unit 33 provided in the control unit 30.

The radiation fluoroscopic image and CT image of the sample obtained by the radiation detector 21b are stored together with the beam output, moving speed, and material powder supply amount of the laser irradiator 14 for each height, length, angle, and stacking of the three-dimensional object. By doing so, it is possible to manage the various data of the modeling apparatus in association with the radiographic image. As a result, by taking out these data at any time, it is possible to freely reproduce or correct the laminated state of the material layers constituting the three-dimensional object, and reverse engineering is possible.

[1-3. Effect of embodiment]
This embodiment has the following effects.
(1) By inspecting the sample box 10 with the radiation detector 21b, the state of filling the material powder in the sample box 10 before modeling and the state of stacking three-dimensional objects in the process of modeling can be seen as a radiation fluoroscopic image at an arbitrary magnification. It can be confirmed by the CT image or CT image. Based on the obtained inspection result, the supply state of the material powder in the three-dimensional object modeling unit 4 can be inferred, and the supply speed and the supply amount of the material powder by the recorder 5 can be adjusted. In addition, it is possible to quickly and easily determine the suitability of the modeling work based on the captured image. As a result, for example, by adjusting the laser beam output, the amount of material powder supplied, the moving speed of the laser irradiator 14, the distance to the melting point, etc. during modeling, a high-quality three-dimensional object without voids or melting defects can be obtained. Can be modeled.

(2) When a partition wall 16 having a passage port 19 is provided in the closed chamber 15 and the passage port 19 is closed by the second shutter 20 when the sample box 10 is taken out to open the take-out port 17 and take out the sample box 10. In addition, only the sample forming portion 7 is opened while maintaining the sealed state of the three-dimensional object forming portion 4 having a large volume. As a result, it is not necessary to open the entire closed chamber 15 for sample inspection, and it is not necessary to refill the entire closed chamber 15 with a large amount of inert gas, which reduces the amount of inert gas and shortens the refilling time. Is possible.

(3) By providing a plurality of sample boxes 10, it is possible to inspect the sample in multiple stages such as before and during modeling. As a result, since it is possible to know the state of the three-dimensional object manufactured by the three-dimensional object modeling unit 4 at each stage, it is possible to obtain information over time such as at which stage modeling defects are likely to occur when the modeling materials are laminated in multiple layers. , Can be freely obtained at intervals desired by the user.

(4) In order to transfer the sample box 10 to the radiation inspection device 21 in a state where the sample is formed inside the sample box 10 and the unmelted material powder is left around the sample, the grip portion 23 touches the sample. There is no damage or deterioration of the sample, and the condition of the molded sample and the unmelted material around it can be inspected at the same time.

(5) Since the laser irradiator 14 is moved between the three-dimensional object modeling unit 4 and the sample forming unit 7 through the passage port 19 of the partition wall 16, only one laser irradiator 14 is required, and the three-dimensional object modeling and the sample The modeling will be performed by the same laser irradiator 14, and the state of the modeled three-dimensional object will be reflected in the sample as it is. As a result, it is possible to accurately know the state of the modeled three-dimensional object based on the information from the sample detected by the radiation inspection device 21.

[2. Other embodiments]
The present invention is not limited to the above-described embodiment, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate. Specifically, it also includes other embodiments such as the following.

(1) As a means for supplying the material powder into the sample box 10, a recoater 5 or a roller similar to the three-dimensional object modeling unit 4 can be used in addition to the spraying by the nozzle. For example, as shown in FIG. 4, instead of the sample box 10, a sample frame portion 3a having the same dimensions as the side wall of the sample box 10 and having an open bottom is fixed to the base 1, and the sample frame portion 3a A sample table 2a that moves in synchronization with the table 2 of the three-dimensional object modeling unit 4 is arranged inside so as to be able to move up and down. A transfer tray 10a is placed on the upper surface of the sample table 2a, and the material powder is supplied onto the transfer tray 10a at the same time as the three-dimensional object modeling portion 4 by the recorder 5.

In this way, after modeling the three-dimensional object, the transfer tray 10a can be gripped by the articulated robot 22 to transfer the sample to the radiation inspection device 21 without touching the sample of the modeled three-dimensional object. can. Further, since the material powder can be supplied to the three-dimensional object modeling unit 4 and the sample forming unit 7 by one recorder 5 without providing the sample forming unit 7 with the dedicated powder supply nozzle 13, the material powder can be supplied between the three-dimensional object and the sample. Thickness management is accurate and easy.

(2) In the above embodiment, the material powder is supplied into the sample box 10 by using the powder supply nozzle 13, but when it is not necessary to observe the state of the molten layer during molding, the material powder is preliminarily used. A plurality of sample boxes 10 filled to a predetermined thickness are prepared, and the sample boxes 10 are irradiated with laser beams having different outputs and moving speeds to inspect the molten state of the material powder. Is also possible.

(3) In the above-described embodiment, by using the sample box 10 and the transfer tray, the transfer mechanism does not directly touch the shaped sample, and there is no risk of the sample being deformed during transfer. If there is no problem in directly gripping the sample by the transport mechanism, the sample forming section 7 is continuously connected to the three-dimensional object modeling section 4 as shown in FIG. 5 without providing the sample box 10 or the transfer tray 10a. Can be provided to form the sample S. In this way, the frame portion 3 of the three-dimensional object modeling portion 4 and the frame portion 3 of the sample forming portion 7 can be integrated, so that the recorder 5 that supplies the material powder to the vertical objective modeling portion 4 can be used as it is on the partition wall 16. The material powder can be supplied into the sample forming portion 7 by passing through the second shutter 20 and invading the sample forming portion 7.

(4) In the above-described embodiment, the recorder 5 and the powder storage unit 6 are integrally provided, but both can be separated from each other. For example, a nozzle for supplying material powder can be provided above the three-dimensional object modeling unit 4. Further, the upper surface opening type powder storage unit 6 may be provided on the side of the three-dimensional object modeling unit 4, and the material powder may be scraped from the upper part of the powder storage unit 6 toward the three-dimensional object modeling unit 4 by the recorder 5.

(5) When the material powder is supplied to the three-dimensional object modeling portion 4 by the recoater 5, the material powder scraped out by the recoater 5 may overflow from the upper edge of the frame portion 3. Therefore, a material powder recovery portion can be provided around the frame portion 3 or between the three-dimensional object modeling portion 4 and the sample forming portion 7.

(6) The number of samples formed in the sample forming unit 7 may be one or a plurality depending on the purpose and the number of inspections. When the number of samples is a plurality, the inside of the sample forming portion 7 is divided into small chambers sealed for each sample by using a separately provided shutter or the like, and the first shutter 18 is formed on the outer wall of each small chamber. Can also be provided. In this way, the amount of inert gas discharged when the sample is taken out can be reduced.

(7) The fluoroscopic image obtained by the present embodiment may be either one or both of a fluoroscopic moving image or a CT fluoroscopic image obtained by a high-speed camera, or may be a still image taken at regular time intervals. good.

1 ... Base 2 ... Table 3 ... Frame part 4 ... Three-dimensional object modeling part 5 ... Recorder 6 ... Powder storage part 7 ... Sample forming part 8 ... Support plate 9 ... Holding mechanism 10 ... Sample box 11 ... Screw plate 12 ... Fixing bolt 13 ... Powder supply nozzle 14 ... Laser irradiator 15 ... Sealed room 16 ... Partition 17 ... Outlet 18 ... First shutter 19 ... Passage port 20 ... Second shutter 21 ... Radiation inspection device 21a ... Radiation generator 21b ... Radiation detector 211 ... Reconstruction unit 212 ... Display unit 22 ... Articulated robot 23 ... Grip unit 24 ... Turntable 25 ... Elevating mechanism 26 ... Rotation mechanism 30 ... Control unit 31 ... Modeling device control unit 311 ... Table control unit 312 ... Recorder control unit 313 ... Laser irradiator control unit 314 ... First shutter and second shutter control unit 315 ... Powder supply nozzle control unit 32 ... Conveyance mechanism control unit 321 ... Articulated robot control unit 322 ... Holding mechanism control unit 33 ... Radiation inspection device control Unit 331 ... Scan control unit 332 ... Positioning control unit

Claims (8)

A base installed on the floor, a table that can be raised and lowered with respect to the base and on which a three-dimensional object to be modeled is placed,
A frame that is placed around the table and the table moves up and down inside it,
An upper surface opening type three-dimensional object modeling portion formed by the table and the frame portion,
A recorder that is arranged above the three-dimensional object modeling section and supplies a powder material of a predetermined thickness into the three-dimensional object modeling section.
A powder storage unit that supplies powder material to the three-dimensional object modeling unit,
A sample forming portion provided on the side of the three-dimensional object modeling portion and
A laser irradiator that is arranged above the three-dimensional object modeling unit and the sample forming unit and moves in at least three-dimensional directions with respect to the table surface.
A closed chamber in which the three-dimensional object modeling portion, the recorder, the sample forming portion, and the laser irradiator are sealed and filled with an inert gas.
A partition wall provided in the closed chamber and airtightly partitioning the three-dimensional object modeling portion and the sample forming portion.
A first shutter provided in the closed chamber and capable of taking the sample in and out of the sample forming portion,
A second shutter provided on the partition wall and closed when the first shutter is opened,
A powder bed type three-dimensional object modeling device equipped with. The powder bed type three-dimensional object modeling device according to claim 1, further comprising a radiation inspection device arranged in the vicinity of the closed chamber and a transport mechanism for taking out the sample in the sample forming portion and setting the sample in the radiation inspection device. The powder bed type three-dimensional object modeling apparatus according to claim 1 or 2, wherein the sample forming unit can form a plurality of the samples. The powder bed type three-dimensional object modeling apparatus according to claim 1 or 2, wherein the sample forming portion has a sample box filled with material powder inside and a holding mechanism thereof. The powder bed type three-dimensional object modeling apparatus according to claim 4, further comprising a nozzle for supplying the material powder into the sample box in synchronization with the supply of the material powder to the three-dimensional object modeling portion by the recorder. The powder bed type three-dimensional object modeling apparatus according to claim 2, wherein the transport mechanism is an articulated robot. The powder bed type three-dimensional object modeling device according to claim 2, wherein the radiation inspection device is a fluoroscopic image display device that converts an output from the radiation detector into image data and displays it. The powder bed type three-dimensional object modeling apparatus according to claim 2, wherein the radiation inspection apparatus is a radiation CT that reconstructs an output from the radiation detector and outputs a cross-sectional image of the three-dimensional object.

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