Additive manufacturing system and additive manufacturing method

Abstract

To provide a laminate shaping system and a laminating shaping method capable of reducing the cost of shaping in a laminate shaping process.SOLUTION: A laminate shaping system includes a powder manufacturing apparatus for manufacturing metal powder using an inert gas, a classifier for classifying the manufactured metal powder and separating it into metal powder of a specified diameter range and remaining metal powder other than the metal powder of the specified diameter range, a laminate shaping apparatus for laminate shaping an object from the metal powder of the specified diameter range, and supplying means of supplying the remaining metal powder other than the metal powder of the specified diameter range resulting from the classifying by the classifier so that the powder manufacturing apparatus can reuse it to manufacture metal powder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an additive manufacturing system and an additive manufacturing method. [Background technology]

[0002] Metal additive manufacturing is being increasingly used in a variety of fields. Because it can manufacture even complex shapes directly from blueprints using metal powder as a raw material, it is primarily used in the manufacturing of custom products in the medical field and for the creation of development prototypes, taking advantage of its rapid manufacturing capabilities. The most common powder bed method currently in use involves irradiating a spread of metal powder with a heat source such as a laser or electron beam, partially melting and solidifying the metal, after which the modeling stage is lowered and the metal powder is spread again and the beam is irradiated again. Three-dimensional shapes are created by repeating this process. Instead of beam irradiation, there are also types that spray and solidify hardened resin, like an inkjet printer, and then heat treat the object to form the model.

[0003] One of the key points is to spread the metal evenly, so the metal powder used must be close to spherical and have a certain range of particle size distribution. Although it depends on the equipment and materials, the recommended particle size range is around 40 to 150 μm for electron beam powder bed methods, and around 20 to 50 μm for laser types, so the required particle size range differs depending on the type.

[0004] Metal powder particle size can change due to the bonding of particles after molding, or the metal that melted and scattered as spatter can be redeposited as fine particles. For this reason, it is common for powder to be classified after molding, and any powder exceeding the particle size range to be used is removed and reused. However, repeated reuse of powder can cause deterioration in quality due to surface oxidation, so when pursuing product quality, the number of times it can be reused is limited, and powder that has been used beyond a certain level may be discarded.

[0005] As a method for producing metal powder, plasma atomization can produce high-quality powder with high sphericity, but it is expensive. Water atomization is widely used as a low-cost method, but the powder becomes irregular, making it unsuitable for additive manufacturing. The most commonly used method is gas atomization, which powders metal by spraying high-pressure gas onto molten metal. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-145526 Summary of the Invention [Problem to be solved by the invention]

[0007] Figure 12 is a graph showing an example of particle size measurement results for metal powder produced by gas atomization. As shown in Figure 12, the produced metal powder has a wide particle size distribution. For additive manufacturing, the resulting powder must be classified, which can reduce the yield by half or more. As such, additive manufacturing processes increase manufacturing costs due to low yields. Furthermore, manufacturing costs increase due to the high cost of the metal powder used as raw material.

[0008] Another feature of metal additive manufacturing is that it uses powder as a raw material, allowing for a wide range of usable materials, but the types of commercially available raw materials are generally limited. Custom-made original materials further increase raw material costs, and the powder removed through classification can become a large amount of waste because it cannot be reused for other purposes in custom-made products. Therefore, the use of original materials further increases the cost of the raw powder, making it difficult to adopt.

[0009] As such, rising manufacturing costs are becoming a problem in additive manufacturing processes.

[0010] The present invention has been made in consideration of the above problems, and aims to provide an additive manufacturing system and an additive manufacturing method that enable reduction in manufacturing costs in an additive manufacturing process. [Means for solving the problem]

[0011] The additive manufacturing system according to a first aspect of the present invention comprises a powder manufacturing apparatus that manufactures metal powder using an inert gas, a classifier that classifies the manufactured metal powder into metal powder within a predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range, an additive manufacturing apparatus that uses the metal powder within the predetermined particle size range obtained by the classification, and a supply means that supplies the remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of the classification in the classifier to the powder manufacturing apparatus so that the powder manufacturing apparatus can reuse the remaining metal powder to manufacture metal powder.

[0012] According to this configuration, the metal powder produced by the powder manufacturing apparatus is classified, and the remaining metal powder outside the specified particle size range is reused as raw material powder for the powder manufacturing apparatus, thereby reducing waste generation and reducing manufacturing costs.

[0013] The above-mentioned additive manufacturing system may further include a second classifier that classifies the metal powder remaining after additive manufacturing in the additive manufacturing device, separating it into metal powder within a predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range, and the additive manufacturing device may perform additive manufacturing using the metal powder within the predetermined particle size range obtained by classification in the second classifier, and the supply means may supply the remaining metal powder other than the metal powder within the predetermined particle size range to the powder manufacturing device so that the powder manufacturing device can reuse it to manufacture metal powder.

[0014] In the above-described additive manufacturing system, the supply means may supply cuttings cut out from an additively manufactured object manufactured by additive manufacturing in the additive manufacturing device to the powder manufacturing device so that the powder manufacturing device can reuse the cuttings to manufacture metal powder.

[0015] An additive manufacturing system according to another aspect of the present invention includes a first production line having a first powder production device that produces metal powder using a gas, a first classifier that classifies the produced metal powder into metal powder within a first particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range, a first additive manufacturing device that performs additive manufacturing using the metal powder within the first particle size range obtained by classification, and a second production line that produces products of lower quality than the first production line, the second powder production device that produces metal powder using a gas. The production line may include a second classifier that classifies the produced metal powder into metal powder in a second particle size range and the remaining metal powder other than the metal powder in the predetermined particle size range, a second additive manufacturing device that performs additive manufacturing using the metal powder in the second particle size range obtained by the classification, and a supply means that supplies the remaining metal powder other than the metal powder in the first particle size range and the remaining metal powder other than the metal powder in the second particle size range to the second powder production device so that the metal powder can be reused in the second powder production device.

[0016] In the above-described additive manufacturing system, the supply means may supply metal powder remaining from additive manufacturing in the first additive manufacturing device to the second powder manufacturing device so that the metal powder can be reused in the second powder manufacturing device, and the supply means may supply metal powder remaining from additive manufacturing in the second additive manufacturing device to the second powder manufacturing device so that the metal powder can be reused in the second powder manufacturing device.

[0017] In the above-mentioned additive manufacturing system, the supply means may supply cuttings cut from additively manufactured objects produced by additive manufacturing in the first additive manufacturing device and the second additive manufacturing device to the second powder manufacturing device so that the metal powder is reused in the second powder manufacturing device.

[0018] An additive manufacturing method according to another aspect of the present invention includes the steps of: a powder manufacturing apparatus manufacturing metal powder using an inert gas; and a classifier classifying the manufactured metal powder into metal powders having a predetermined particle size range and remaining metal powders other than the metal powders having the predetermined particle size range. The method includes a procedure in which an additive manufacturing device performs additive manufacturing using metal powder within a predetermined particle size range obtained by the classification, and a procedure in which a storage device supplies the remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier so that the powder manufacturing device can reuse it to manufacture metal powder. [Effects of the Invention]

[0019] According to one aspect of the present invention, metal powder produced by a powder manufacturing apparatus is classified, and the remaining metal powder outside a predetermined particle size range is reused as raw material powder for the powder manufacturing apparatus, thereby suppressing waste generation and reducing manufacturing costs. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing the configuration of an additive manufacturing system according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing an additive manufacturing process according to a first embodiment. [Figure 3] FIG. 1 is a diagram illustrating an example of the configuration of a powder manufacturing apparatus. [Figure 4] FIG. 1 is a diagram illustrating an example of the configuration of an additive manufacturing apparatus. [Figure 5] FIG. 1 is a diagram showing an example of the configuration of a gas scrubber that uses a dry exhaust gas scrubbing process. [Figure 6] FIG. 2 is a diagram showing an example of an inert gas supply line. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a gas scrubber that uses a wet exhaust gas scrubbing process. [Figure 8] FIG. 10 is a diagram showing the configuration of an additive manufacturing system according to a second embodiment. [Figure 9] FIG. 10 is a schematic diagram showing an additive manufacturing process according to a second embodiment. [Figure 10] FIG. 10 is a diagram showing the configuration of an additive manufacturing system according to a third embodiment. [Figure 11] 10A to 10C are schematic diagrams illustrating an additive manufacturing process according to a third embodiment. [Figure 12] 1 is a graph showing an example of particle size measurement results of metal powder produced by gas atomization. [Figure 13] FIG. 10 is a schematic diagram showing an additive manufacturing process according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, each embodiment will be described with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0022] <Comparative Example> Before describing this embodiment, a process of a comparative example will be described using FIG. 13. FIG. 13 is a schematic diagram showing an additive manufacturing process according to the comparative example. As shown in FIG. 13, in the comparative example, additive manufacturing is performed from powder raw material in an atmosphere of argon gas supplied from an argon tank (step S510). The argon exhaust gas after use is discarded. The remaining metal powder is classified (step S520), and metal powder within a predetermined particle size range is reused as powder raw material. On the other hand, metal powder outside the predetermined particle size range after classification is discarded. The support members of the structure obtained by additive manufacturing are cut by post-processing (step S530), and the cut pieces cut out by cutting are discarded.

[0023] First Embodiment In contrast, in the first embodiment, in the process of producing metal powder, which is the raw material for metal additive manufacturing, and in the manufacturing process using metal additive manufacturing, both a powder manufacturing device and an additive manufacturing device are installed side by side, and the metal powder produced by the powder manufacturing device is classified, and the remaining metal powder outside the specified particle size range is reused as raw material powder for the powder manufacturing device, thereby reducing waste generation and reducing manufacturing costs.

[0024] One of the reasons for the increase in manufacturing costs mentioned above is the use of a large amount of inert gas during manufacturing. A large amount of high-pressure gas is sprayed during powder production. Past performance has shown that one liquefied argon (Ar) cylinder (capacity 200 kg) can produce 20 kg of powder (equivalent to iron). ) and uses a large amount of inert gas.

[0025] Even in the case of the currently mainstream laser-type powder bed method, inert gas (such as argon gas) is used. To prevent oxidation of the metal during melting, inert gas is flowed at a rate of several tens of liters per minute during the manufacturing process. Since the manufacturing process is repeated layer by layer, it can take hundreds of hours to manufacture a large product, requiring a large amount of inert gas to complete the manufacturing process. Furthermore, when manufacturing a large number of products, multiple manufacturing devices must be installed. As a result, large amounts of inert gas must be supplied to each device, and gas consumption is one of the factors that increase running costs.

[0026] Considering the entire process from powder molding to product manufacturing, a large amount of inert gas is consumed throughout the entire process, which is one of the reasons for the increase in manufacturing costs. To address this issue, the additive manufacturing system according to the first embodiment reuses the inert gas (e.g., argon gas) used in both the metal powder manufacturing process, which is the raw material for metal additive manufacturing, and the manufacturing process using metal additive manufacturing, thereby reducing manufacturing costs caused by the consumption of inert gas.

[0027] In the following embodiments, the use of argon (Ar) gas as the inert gas will be described as an example.

[0028] First Embodiment Fig. 1 is a diagram showing the configuration of an additive manufacturing system according to a first embodiment. As shown in Fig. 1, the additive manufacturing system S1 includes a powder manufacturing apparatus 1, a classifier 2, an additive manufacturing apparatus 3, a suction device 4, a classifier 5 (also referred to as a second classifier), a gas washer 6, a compressor 7, a tank 8, and supply means 90. The supply means 90 supplies the remaining metal powder other than the metal powder within a predetermined particle size range obtained as a result of classification in the classifier 2 so that the powder manufacturing apparatus 1 can reuse it to manufacture metal powder. The supply means 90 includes, for example, a storage device 9 and a pipe P29 connecting the storage device 9 and the classifier 2.

[0029] When considering the entire process, the amount of inert gas used during powder production and modeling has a significant impact on costs. Therefore, by installing a powder modeling device and an additive manufacturing device side by side, argon gas can be reused, reducing the cost of the entire process.

[0030] Specifically, argon gas is used to cool the liquid metal during powder production, and the exhaust gas contains argon gas and metal powder. After the raw metal powder is recovered, fine particles that cannot be collected even with a filter are included as impurities. In additive manufacturing, metal vapors volatilized by the beam are entrained in the gas and become impurities.

[0031] To remove these, the gas is cleaned in a gas washer 6, then pressurized in a compressor 7 and stored as high-pressure gas in a tank 8. The gas is supplied from this tank 8 to the powder manufacturing device 1 and the additive manufacturing device 3. By circulating the gas in this way, it is possible to reduce gas consumption and running costs.

[0032] The produced powder is also classified, and metal powder within a specified particle size range appropriate for the purpose is used as a raw material for additive manufacturing. By reusing the powder that is rejected during classification as a raw material, it is possible to eliminate the waste of raw materials during powder production, providing a production method with a low environmental impact throughout the entire process. Powders that are not suitable for additive manufacturing include large and small particle sizes, but because small particle sizes are susceptible to the risk of dust explosions and deterioration due to surface oxidation, it is desirable to fill the storage device 9 with an inert gas such as argon gas.

[0033] The current equipment uses liquefied argon gas (capacity 200 kg) and can dissolve approximately 20 kg of iron (Fe For example, if the material cost of stainless steel is calculated at 1,000 yen / kg, the material cost for 20 kg is 20,000 yen, and the cost of the liquefied argon cylinder is 5 Assuming a raw material cost of 3,000 yen and a yield of 50%, the raw material cost to manufacture 10 kg of product is 73,000 yen / 10 kg. However, by making the argon gas and materials reusable, the raw material cost required will be 10,000 yen / 10 kg, which is a significant cost reduction.

[0034] 2 is a schematic diagram showing the additive manufacturing process according to the first embodiment. The additive manufacturing method will be described with reference to FIG.

[0035] (Step S10) The raw materials and the recycled raw materials obtained from the storage device 9 are adjusted in composition.

[0036] (Step S20) Next, the powder manufacturing apparatus 1 melts the raw material after the composition adjustment, and manufactures metal powder using an inert gas (for example, argon gas).

[0037] (Step S30) Next, the classifier 2 classifies the metal powder produced by the powder production apparatus 1 into metal powders within a predetermined particle size range.

[0038] (Step S40) Next, the layered manufacturing apparatus 3 performs layered manufacturing using the metal powder having a predetermined particle size range obtained by classification.

[0039] (Step S50) Next, the suction machine 4 sucks in the metal powder remaining after additive manufacturing in the additive manufacturing device 3, and the classifier 5 classifies the sucked metal powder, separating it into metal powder within a predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range. As a result, the additive manufacturing device 3 performs additive manufacturing again using the metal powder within the predetermined particle size range obtained by classification in the classifier 5. Furthermore, the remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier 5 is discarded.

[0040] (Step S60) In post-processing, a finished product is made by cutting the support member from the structure obtained by the additive manufacturing apparatus 3. The cut pieces obtained by cutting are discarded.

[0041] (Step S70) Gas washer 6 cleans the gas used in powder manufacturing apparatus 1 and the gas discharged from the layered manufacturing apparatus.

[0042] (Step S80) Next, the compressor 7 compresses the gas after cleaning.

[0043] (Step S90) Next, tank 8 stores compressed gas (for example, argon gas). As a result, the gas is supplied from tank 8 to powder manufacturing apparatus 1 and layered manufacturing apparatus 3. This allows the inert gas to be reused.

[0044] (Step S100) The remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier 2 is collected via pipe P29, and storage device 9 stores this metal powder so that it can be reused to manufacture metal powder by powder manufacturing apparatus 1. Then, the metal powder stored in storage device 9 is supplied as a recycled raw material, and its composition is adjusted with that of the raw material, and the adjusted raw material is supplied to the powder manufacturing apparatus 1.

[0045] By installing the powder production equipment 1 and the additive manufacturing equipment 3 side by side, the argon gas recycling equipment can be shared, reducing the cost of the entire process. Furthermore, metal powder is unsuitable for long-term storage due to the risk of explosion and deterioration. Therefore, by installing the equipment side by side, it is possible to produce only the amount of metal powder needed at the time. This minimizes the amount of storage required.

[0046] Fig. 3 is a diagram showing an example of the configuration of a powder manufacturing apparatus. As shown in Fig. 3, powder manufacturing apparatus 1 includes melting chamber 11 having a through-hole in the bottom surface, melting crucible 111 having a hole in the bottom that communicates with the through-hole, quenching chamber 112 provided below melting chamber 11, and gas pipe 113 inserted approximately horizontally into the top of quenching chamber 112. Powder manufacturing apparatus 1 also includes first powder collection box 12 communicating with the bottom of quenching chamber 112, cyclone dust collector 13 communicating with first powder collection box 12, and second powder collection box 14 communicating with the bottom of cyclone dust collector 13. Powder manufacturing apparatus 1 also includes dry filter 15 and third powder collection box 16 communicating with the bottom of dry filter 15.

[0047] In gas atomization, the raw material components are adjusted to achieve the desired alloy composition, and the metal is melted in a vacuum using methods such as high-frequency induction heating. The molten metal is allowed to fall freely from a hole at the bottom of the melting crucible 111, and is rapidly cooled by spraying high-pressure argon gas (although inert gases such as nitrogen can also be used) onto the fallen molten metal, forming powder metal. The particle size distribution of the resulting powder can be controlled by adjusting the gas pressure and spraying method. The produced powder is collected in the first powder collection box 12 located below the quenching chamber 112, but is carried to subsequent stages by the high-pressure gas flow. Therefore, the powder is collected using a cyclone dust collector 13 or dry filter 15, and fine powder that cannot be collected by the dry filter 15 is discharged from the powder production apparatus 1 along with argon gas.

[0048] The recovered metal powder is classified and adjusted to the desired particle size distribution. Because classifying fine particles takes time, efficient operation is possible by adjusting the mesh size of the dry filter according to the intended use of the powder. For example, if metal powder for electron beams requires a particle size of 40 μm or more, using a filter that allows particles 40 μm or smaller to pass through makes it possible to remove unwanted particle sizes in advance.

[0049] FIG. 4 is a diagram showing an example of the configuration of an additive manufacturing apparatus. Here, the additive manufacturing apparatus 3 is, as an example, a laser-type powder bed metal additive manufacturing apparatus. As shown in FIG. 4, the additive manufacturing apparatus 3 includes an additive manufacturing chamber 30 filled with argon gas, which is an example of an inert gas, a laser 31 provided in the additive manufacturing chamber 30, and a mirror 32 that reflects the laser light emitted from the laser 31. The additive manufacturing apparatus 3 also includes a powder supply flattening plate 33, a manufacturing stage 34, powder supply containers 35 and 36, and a powder suction nozzle 39 inserted into the additive manufacturing chamber 30. The additive manufacturing apparatus 3 also includes a switching valve 40, a pipe 41 having one end connected to the additive manufacturing chamber 30 and the other end connected to the switching valve 40, a pipe 42 having one end connected to the switching valve 40, and a pipe 43 having one end connected to the switching valve 40.

[0050] In order to open the additive manufacturing chamber 30 for the necessary preparations before modeling, the additive manufacturing chamber 30 is first evacuated and argon gas is allowed to flow until the atmosphere is sufficiently replaced with argon gas, after which modeling begins.

[0051] The additive manufacturing device 3 uses a powder supply flattening plate 33 to form a flat powder bed from metal powder in powder supply containers 35 and 36. Laser light controlled by a mirror 32 partially melts the metal powder on the manufacturing stage 34 to form a molded object 37, with unmelted metal powder 38 remaining around the molded object 37. To prevent the risk of some of the evaporated metal re-precipitating in the surrounding area, argon gas (or an inert gas such as nitrogen) is introduced, and gas containing the metal vapor, leaked air, and other impurities is discharged to the outside of the system via a switching valve 40. Before manufacturing, the switching valve 40 connects pipes 41 and 42, and these gases are discarded. During manufacturing, the switching valve 40 discharges the exhaust gas to pipe 41 and gas washer 6 for cleaning.

[0052] After modeling is completed, unmelted metal powder 38 and surplus powder remaining during powder bed formation are collected by the suction machine 4 via a powder suction nozzle 39 and supplied to the classifier 5. In FIG. 5, there is a first sieve 52 and a second sieve 53 located downstream of the first sieve 52 and having finer (denser) mesh than the first sieve 52. Of the powder collected from the suction machine 4, the powder that passed through the first sieve 52 but not the second sieve 53 is returned to the powder supply containers 35, 36 and reused in the additive manufacturing apparatus. On the other hand, the powder that did not pass through the first sieve 52 and the powder that passed through the second sieve 53 are discarded.

[0053] FIG. 5 shows an example of the configuration of a gas scrubber using a dry process for exhaust gas scrubbing. As shown in FIG. 5, the gas scrubber 6 includes a chamber 61 having an inertial dust collector 611, a chamber 62 connected to the chamber 61 and having a dry filter 621, and a blower 63 connected to the chamber 62. The gas scrubber 6 also includes an activated carbon filter 64, adsorption tanks 65 and 66, a pipe P61 connected to the activated carbon filter 64 at one end, and branch pipes P62 and P63 branching off from the pipe P61. The adsorption tanks 65 and 66 are filled with, for example, zeolite A. The branch pipe P62 has one end connected to the pipe P61 and the other end connected to the adsorption tank tank 65, and is provided with a valve B62. The branch pipe P63 has one end connected to the pipe P61 and the other end connected to the adsorption tank tank 66, and is provided with a valve B63. The gas scrubber 6 further includes a vacuum pump 67, a pipe P64 having one end connected to the adsorption tank 65 and the other end connected to the vacuum pump 67, a valve B61 provided on the pipe P64, a pipe P65 having one end connected to the adsorption tank 66 and the other end connected to the vacuum pump 67, and a valve B64 provided on the pipe P65.

[0054] The inert gas (here, argon gas as an example) used in producing the metal powder is supplied to the chamber 61 from the powder production apparatus 1. Similarly, the inert gas (here, argon gas as an example) used in metal additive manufacturing is supplied to the chamber 61 from the additive manufacturing apparatus 3.

[0055] In chamber 61, an inertial dust collector 611, such as a cyclone, collects large particles from the supplied inert gas, and the remaining gas is discharged to chamber 62. In chamber 62, a dry filter 621, such as a bag filter, collects fine particles from the remaining gas. If pressure loss in dry filter 621 makes it difficult for gas to pass through, a blower 63 is installed to promote gas flow. The gas that passes through dry filter 621 is discharged by blower 63, and impurities are then removed by activated carbon filter 64 and adsorption tanks 65 and 66. To enable continuous operation, multiple adsorption tanks, such as adsorption tanks 65 and 66, are installed in parallel. Vacuum pump 67 is used to reduce pressure and remove adsorbed materials from the adsorption tanks in the non-gas-passing series, allowing them to be regenerated.

[0056] Fig. 6 is a diagram showing an example of an inert gas supply line. As shown in Fig. 6, a pipe P70 is connected to the inlet of the compressor 7, and the pipe P70 branches into branch pipes P71 and P72. The branch pipe P71 communicates with the adsorption tank 65, and the branch pipe P72 communicates with the adsorption tank 66. The branch pipe P71 is provided with a valve B71, and the branch pipe P72 is provided with a valve B72. As a result, the inert gas (e.g., argon or nitrogen) discharged from the adsorption tanks 65 and 66 is supplied to the compressor 7, where it is compressed and pressurized.

[0057] The outlet of the compressor 7 is connected to one end of a pipe P73, the other end of which is connected to a tank 8, and a valve B73 is provided on this pipe P73. As a result, the inert gas compressed by the compressor 7 is supplied to the tank 8 and stored therein.

[0058] One end of pipe P80 is connected to tank 8, and the other end of pipe P80 is connected to gas concentration system 73. This allows the concentration of gas discharged from tank 8 to be measured. In addition, branch pipes P91 and P92 are provided branching off from pipe P90. A flow meter 71 and a valve B81 are provided in branch pipe P91, and this branch pipe P91 is connected to powder manufacturing apparatus 1. In addition, a flow meter 72 and a valve B82 are provided in branch pipe P92, and this branch pipe P92 is connected to layered manufacturing apparatus 3. This allows the inert gas stored in the tank to be supplied to powder manufacturing apparatus 1 and layered manufacturing apparatus 3 at the required flow rate.

[0059] As described above, the additive manufacturing system S1 according to this embodiment comprises a powder manufacturing apparatus 1 that manufactures metal powder using an inert gas, a classifier 2 that classifies the manufactured metal powder and separates it into metal powder within a predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range, an additive manufacturing apparatus 3 that performs additive manufacturing using the metal powder within the predetermined particle size range obtained by the classification, and a supply means 90 that supplies the remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of the classification in the classifier 2 so that the powder manufacturing apparatus 1 can reuse it to manufacture metal powder.

[0060] According to this configuration, the metal powder produced by the powder manufacturing apparatus is classified, and the remaining metal powder outside the specified particle size range is reused as raw material powder for the powder manufacturing apparatus, thereby reducing waste generation and reducing manufacturing costs.

[0061] In addition, the additive manufacturing system S2 of this embodiment is equipped with a gas washer 6 that cleans the gas after use in the powder manufacturing apparatus 1 and the gas discharged from the additive manufacturing apparatus 3, a compressor 7 that compresses the cleaned gas, and a tank 8 that stores the compressed gas, and the gas is supplied from the tank 8 to the powder manufacturing apparatus 1 and the additive manufacturing apparatus 3.

[0062] According to this configuration, the gas used in the powder manufacturing apparatus 1 and the gas discharged from the layered manufacturing apparatus 3 can be reused, thereby reducing gas consumption and running costs.

[0063] <Modification of the first embodiment> The gas cleaning device is not limited to those using a dry exhaust gas cleaning process, but may also use a wet exhaust gas cleaning process. If metal vapor emitted from the additive manufacturing device adheres to any part of the system and leads to problems, it is desirable to use wet gas cleaning using a scrubber or similar. The metal vapor can be cooled with water, precipitated, and removed, making it possible to remove it reliably with a scrubber. In the latter stage, it is desirable to dehumidify the gas using a dehumidifier or similar device to remove the large amount of moisture contained in the gas.

[0064] Fig. 7 is a diagram showing an example of the configuration of a gas scrubber using a wet exhaust gas scrubbing process. As shown in Fig. 7, the gas scrubber 6b includes a water scrubber 80, a dehumidifier 83 communicating with the water scrubber 80, a blower 84 communicating with the dehumidifier 83, an activated carbon filter 85 communicating with the blower 84, and adsorption tanks 86 and 87. The gas scrubber 6b further includes a pipe P81 having one end connected to an activated carbon filter 85, and branch pipes P82 and P83 branching off from the pipe P81. The adsorption tanks 86 and 87 are filled with, for example, zeolite A. The branch pipe P82 has one end connected to the pipe P81 and the other end connected to the adsorption tank 86, and is provided with a valve B82. The branch pipe P83 has one end connected to the pipe P81 and the other end connected to the adsorption tank 87, and is provided with a valve B83. The gas scrubber 6b further includes a vacuum pump 88, a pipe P84 having one end connected to the adsorption tank 86 and the other end connected to the vacuum pump 88, a valve B81 provided on the pipe P84, a pipe P85 having one end connected to the adsorption tank 87 and the other end connected to the vacuum pump 88, and a valve B84 provided on the pipe P85.

[0065] The water scrubber 80 has a chamber 81 to which used gas is supplied and a pump 82 connected to the chamber. The chamber 81 has a filler 811 and pipes 812 spaced apart above the filler 811. The pipes 812 have multiple holes at the bottom, and water supplied from the pump 82 is discharged through the holes at the bottom of the pipes 812. This allows the metal vapor to be cooled by the water, precipitated, and removed, ensuring reliable removal by the scrubber. The discharged gas is then passed through a dehumidifier 83, where the large amount of moisture contained in the gas is removed. The gas that has passed through the dehumidifier 83 is discharged by a blower 63, and impurities are then removed through an activated carbon filter 85 and adsorption tanks 86 and 97.

[0066] <Second embodiment> In the first embodiment, the powder used in additive manufacturing is recovered and classified, and metal powder outside the specified particle size range, such as granulated powder, is reused for manufacturing. This results in a higher raw material yield and a lower environmental impact than conventional methods such as casting and cutting. Meanwhile, metal powder outside the specified particle size range after classification following additive manufacturing is discarded. In addition, in subsequent processes, removed support members and chips from finishing are also generated, and these are disposed of as waste. These aspects impose an environmental burden, and further reduction of the environmental burden is desirable. To address this issue, in the second embodiment, these waste materials are also recovered and reused as raw materials in the powder manufacturing device, thereby reducing manufacturing costs and further eliminating waste, thereby further reducing the environmental burden.

[0067] FIG. 8 is a diagram showing the configuration of an additive manufacturing system according to a second embodiment. FIG. 9 is a schematic diagram showing an additive manufacturing process according to the second embodiment. As shown in FIGS. 8 and 9, the additive manufacturing system S2 according to the second embodiment differs from the additive manufacturing system S1 according to the first embodiment of FIG. 1 in that the remaining metal powders other than those within a predetermined particle size range after classification by the classifier 5 are collected and stored in a storage device 9 (see step S150 in FIG. 9). Another difference is that chips discarded by cutting an additively manufactured object manufactured by additive manufacturing in the additive manufacturing apparatus 3 are collected and stored in the storage device 9 (see step S160 in FIG. 9). Thus, the remaining metal powders and chips stored in the storage device 9 are also subjected to composition adjustment together with the raw materials as recycled raw materials, and the raw materials after the composition adjustment are supplied to the powder manufacturing apparatus 1 (see step S200 in FIG. 9).

[0068] 9 are the same as steps S10 to S40 in FIG. 2, and steps S170 to S190 are the same as steps S70 to S90 in FIG. 2, so a description thereof will be omitted.

[0069] <Third embodiment> Next, a third embodiment will be described. The recovered recycled raw materials may contain more impurities than new raw materials due to oxidation of the powder surface or oxidation caused by heat during cutting, resulting in a decrease in quality. On the other hand, typical applications of additive manufacturing products include fields that require strict quality control, such as the medical field, where custom-made products are required, and the aerospace industry, where there is a strong demand for lightweight components due to complex structures. On the other hand, in fields that take advantage of the benefits of rapid manufacturing, development prototypes are the main application. Development prototypes only require the ability to confirm the shape and basic performance, and in most cases material quality is not an issue.

[0070] Therefore, in the third embodiment, a production line is constructed that reflects the characteristics of additive manufacturing and is suited to the application. This makes it easier to reuse raw materials. In other words, for products that require high quality, the first production line uses powder produced from raw materials with few impurities, and the powder raw material used in additive manufacturing is not reused or is minimized. This makes it possible to maintain high product quality. On the other hand, by using recycled raw materials in the second production line that produces development prototypes, etc., surplus raw materials can be used without waste. This reduces manufacturing costs.

[0071] An example of an additive manufacturing system according to the third embodiment will be described below with reference to Fig. 10 and Fig. 11. Fig. 10 is a diagram showing the configuration of the additive manufacturing system according to the third embodiment. Fig. 11 is a schematic diagram showing the additive manufacturing process according to the third embodiment.

[0072] As shown in FIG. 10, an additive manufacturing system S3 according to the third embodiment includes a first manufacturing line L1, a second manufacturing line L2, and a supply unit 90b. The supply unit 90b includes, for example, a storage device 9. The first manufacturing line L1 includes a powder manufacturing apparatus 1a (also referred to as the first powder manufacturing apparatus) to which raw materials are supplied after composition adjustment from raw materials, a classifier 2a (also referred to as the first classifier), and an additive manufacturing apparatus 3a (also referred to as the first additive manufacturing apparatus). The second manufacturing line L2 includes a powder manufacturing apparatus 1b (also referred to as the second powder manufacturing apparatus) to which raw materials are supplied after composition adjustment of raw materials and recycled raw materials, a classifier 2b (also referred to as the second classifier), an additive manufacturing apparatus 3b (also referred to as the third additive manufacturing apparatus), a suction device 4, and a classifier 5. The recycled raw materials are supplied from the storage device 9. In the storage device 9, the remaining metal powder other than metal powder within a specified particle size range is collected and stored by the classifier 2a, the remaining metal powder after additive manufacturing is collected and stored by the additive manufacturing device 3a, and cuttings are supplied from post-processing and stored.

[0073] Next, an additive manufacturing method according to a third embodiment will be described with reference to FIG.

[0074] (Step S310) The ingredients are adjusted using the raw materials.

[0075] (Step S320) Next, the powder manufacturing apparatus 1a melts the raw material after the composition adjustment, and manufactures metal powder using an inert gas (for example, argon gas).

[0076] (Step S330) Next, the classifier 2a classifies the metal powder produced by the powder production apparatus 1a into metal powders within a predetermined particle size range.

[0077] (Step S340) Next, the layered manufacturing apparatus 3a performs layered manufacturing using the metal powder in the first particle size range obtained by classification.

[0078] (Step S410) The components of the raw material and the recycled raw material obtained from the storage device 9 are adjusted.

[0079] (Step S420) Next, the powder manufacturing apparatus 1b melts the raw material after the composition adjustment and manufactures metal powder using an inert gas (for example, argon gas).

[0080] (Step S430) Next, the classifier 2b classifies the metal powder produced by the powder production apparatus 1b into metal powders within a predetermined particle size range.

[0081] (Step S440) Next, the additive manufacturing apparatus 3b performs additive manufacturing using the metal powder of the second particle size range obtained by classification. Here, the first particle size range and the second particle size range may be the same or different.

[0082] (Step S450) Next, the suction machine 4 suctions the metal powder remaining after the additive manufacturing in the additive manufacturing apparatus 3b, and the classifier 5 classifies the suctioned metal powder into metal powder within a predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range. As a result, the additive manufacturing apparatus 3b performs additive manufacturing again using the metal powder within the predetermined particle size range obtained by classification in the classifier 5. The remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier 5 is discarded.

[0083] (Step S460) In post-processing, a finished product is produced by cutting the support members from the structure obtained by the additive manufacturing apparatus 1b in step S340 and from the structure obtained by the additive manufacturing apparatus 3b in step S450.

[0084] (Step S500) In step S330, the remaining metal powder other than the metal powder within a predetermined particle size range obtained as a result of classification in classifier 2a is collected and stored in storage device 9. Also, in step S340, the remaining metal powder after additive manufacturing is collected and stored in storage device 9. Also, in step S340, the remaining metal powder after classification is collected and stored in storage device 9. Also, in step S450, the remaining metal powder after classification is collected and stored in storage device 9. Also, in step S460, the chips obtained by cutting are collected in step S500 and stored in storage device 9. Then, the metal powder stored in storage device 9 is supplied as recycled raw material, its composition is adjusted with that of the raw material, and the adjusted raw material is supplied to powder manufacturing apparatus 1b.

[0085] As described above, the additive manufacturing system S3 according to the third embodiment comprises a first manufacturing line L1 having a powder manufacturing device 1a that manufactures metal powder using gas, a classifier 2a that classifies the manufactured metal powder into metal powder within a first particle size range and the remaining metal powder other than the metal powder within the specified particle size range, and an additive manufacturing device 3a that performs additive manufacturing using the metal powder within the first particle size range obtained by the classification. Furthermore, the additive manufacturing system S3 is a second manufacturing line L2 that manufactures products of lower quality than the first manufacturing line L1, and is equipped with a powder manufacturing device 1b that manufactures metal powder using gas, a classifier 2b that classifies the manufactured metal powder and separates it into metal powder within a second particle size range and the remaining metal powder other than the metal powder within the specified particle size range, and an additive manufacturing device 3b that performs additive manufacturing using the metal powder within the second particle size range obtained by the classification. Furthermore, the additive manufacturing system S3 is provided with a supply means 90b that supplies the remaining metal powders other than the metal powders in the first particle size range and the remaining metal powders other than the metal powders in the second particle size range to the powder manufacturing apparatus 1b so that the metal powders are reused in the powder manufacturing apparatus 1b.

[0086] This configuration allows the first manufacturing line to use powder produced from raw materials with fewer impurities, and to minimize or eliminate the reuse of powder raw materials during additive manufacturing. This makes it possible to maintain high product quality on the first manufacturing line L1. Meanwhile, by reusing the remaining metal powder from the first manufacturing line L1 and the second manufacturing line L2 on the second manufacturing line, it is possible to reduce the manufacturing costs of products on the second manufacturing line L2.

[0087] In the additive manufacturing system S3 according to the third embodiment, the supply means 90b supplies the metal powder remaining after additive manufacturing in the additive manufacturing apparatus 1a to the second powder manufacturing apparatus 1b so that the metal powder can be reused in the powder manufacturing apparatus 1b. The supply means 90b also supplies the metal powder remaining after additive manufacturing in the additive manufacturing apparatus 3b (specifically, the remaining powder other than the reused powder discharged from the classifier 5, for example) to the second powder manufacturing apparatus 1b so that the metal powder can be reused in the powder manufacturing apparatus 1b.

[0088] This allows the metal powder to be reused, thereby reducing the manufacturing costs of products on the second manufacturing line L2.

[0089] Furthermore, the supply means 90b supplies cuttings cut from the layered objects manufactured by layered manufacturing in the layered manufacturing apparatus 3a and the layered manufacturing apparatus 3b to the powder manufacturing apparatus 1b so that the metal powder can be reused in the powder manufacturing apparatus 1b. This allows further reuse of the metal powder, thereby reducing the manufacturing cost of products in the second manufacturing line L2.

[0090] As in the first and second embodiments, the additive manufacturing system S3 according to the third embodiment may further include a gas washer 6, a compressor 7, and a tank 8. This allows the gases discharged from the powder manufacturing apparatus 1a, the additive manufacturing apparatus 3a, the powder manufacturing apparatus 1b, and the additive manufacturing apparatus 3b to be reused.

[0091] As described above, the present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0092] 1, 1a, 1b powder manufacturing equipment 11 Melting chamber 111 Melting pot 112 Quenching chamber 113 Gas Pipe 12 First powder collection box 13 Cyclone dust collector 14 Second powder collection box 15 Dry Filter 16. Third powder collection box 2a, 2b classifier 3 Additive manufacturing equipment 30 Additive Manufacturing Chamber 31 Laser 32 Mirror 33 Powder feeding flattening plate 34 Modeling Stage 35, 36 Powder supply container 39 Powder suction nozzle 40 Switching valve 41, 42, 43 Piping 5 Classifier 52 First Sieve 53 Second Sieve 6, 6b Gas Cleaner 61 Chamber 62 Inertial dust collector 62 Chamber 63 Blower 64 Activated carbon filter 65 Adsorption tank 66 Vacuum Pump 67 Vacuum Pump 7 Compressor 8. Tank 80 Water Scrubber 81 Chamber 82 Pump 83 Blower 85 Activated carbon filter 86, 87 Adsorption tank 88 Vacuum Pump S1, S2, S3 Additive Manufacturing Systems

Claims

1. a powder manufacturing apparatus for manufacturing metal powder using an inert gas; The produced metal powder is classified to obtain metal powders having a predetermined particle size range and metal powders having a predetermined particle size range. a classifier for separating the metal powder into the remaining metal powder other than the metal powder of the above-mentioned type; An additive manufacturing device for additive manufacturing using the metal powder having a predetermined particle size range obtained by classification. Place and The remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier The powder manufacturing apparatus is configured to reuse the metal powder to manufacture metal powder. supplying means for supplying the device; The gas used in the powder manufacturing device and the gas discharged from the additive manufacturing device are washed. a gas scrubber that purifies the air, a compressor for compressing the gas after cleaning; a tank for storing the compressed gas; Equipped with Gas is supplied from the tank to the powder manufacturing apparatus and the additive manufacturing apparatus. Additive manufacturing system.

2. a powder manufacturing apparatus for manufacturing metal powder using an inert gas; The produced metal powder is classified to obtain metal powders having a predetermined particle size range and metal powders having a predetermined particle size range. a classifier for separating the metal powder into the remaining metal powder other than the metal powder of the above-mentioned type; An additive manufacturing device for additive manufacturing using the metal powder having a predetermined particle size range obtained by classification. Place and The remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier The powder manufacturing apparatus is configured to reuse the metal powder to manufacture metal powder. supplying means for supplying the device; The metal powder remaining after the additive manufacturing process in the additive manufacturing device is classified to obtain metal powders within a predetermined particle size range. a second classifier for classifying the metal powder into the metal powder within the predetermined particle size range and the remaining metal powder other than the metal powder within the predetermined particle size range; 、 Equipped with The additive manufacturing device is configured to classify metal powder having a predetermined particle size range obtained by classification using the second classifier. Using the powder, additive manufacturing is carried out. The supplying means supplies the remaining metal powder other than the metal powder having the predetermined particle size range to the powder mixture. The powder is supplied to the powder manufacturing device so that the manufacturing device can reuse it to manufacture metal powder. Additive manufacturing system.

3. a powder manufacturing apparatus for manufacturing metal powder using an inert gas; The produced metal powder is classified to obtain metal powders having a predetermined particle size range and metal powders having a predetermined particle size range. a classifier for separating the metal powder into the remaining metal powder other than the metal powder of the above-mentioned type; An additive manufacturing device for additive manufacturing using the metal powder having a predetermined particle size range obtained by classification. Place and The remaining metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification in the classifier The powder manufacturing apparatus is configured to reuse the metal powder to manufacture metal powder. supplying means for supplying the device; Equipped with The supplying means supplies a layered object manufactured by layered manufacturing in the layered manufacturing device. The cuttings cut out from the powder are reused by the powder manufacturing device to manufacture metal powder. Supply to the powder manufacturing equipment Additive manufacturing system.

4. A first powder manufacturing device for manufacturing metal powder using a gas, and a second powder manufacturing device for separating the manufactured metal powder. The metal powders are classified into a first particle size range and the remaining metal powders other than the metal powders in the predetermined particle size range. a first classifier for classifying the metal powder into the first particle size range obtained by the classification; a first manufacturing line including a first additive manufacturing apparatus for additive manufacturing using the additive manufacturing method; a second production line that produces a product of lower quality than the first production line, a second powder production device for producing metal powder using the above-mentioned method; and a second powder production device for classifying the produced metal powder. The metal powder is separated into a metal powder having a second particle size range and the remaining metal powder other than the metal powder having the predetermined particle size range. a second classifier for classifying the metal powder in the second particle size range obtained by the classification; a second manufacturing line having a second additive manufacturing apparatus for layer-by-layer manufacturing; The remaining metal powders other than the metal powders in the first particle size range, and the metal powders in the second particle size range The remaining metal powder other than the powder is recycled in the second powder manufacturing apparatus. supplying means for supplying the second powder manufacturing apparatus as described above; An additive manufacturing system comprising:

5. The supplying means supplies the metal powder remaining after the additive manufacturing process in the first additive manufacturing device to the The metal powder is supplied to the second powder manufacturing apparatus so as to be reused in the second powder manufacturing apparatus. death, The supplying means supplies the metal powder remaining after the additive manufacturing process in the second additive manufacturing device to the The metal powder is supplied to the second powder manufacturing apparatus so as to be reused in the second powder manufacturing apparatus. do The additive manufacturing system of claim 4 .

6. The supplying means is a means for supplying the first and second additive manufacturing devices The cuttings cut out from the layered object formed by the shape are mixed with the second powder. and supplying the powder to the second powder production device so that the powder can be reused in the second powder production device. The additive manufacturing system according to claim 4 or 5.

7. A procedure for producing metal powder by a powder production device using an inert gas; A classifier classifies the produced metal powder to obtain metal powders in a predetermined particle size range and metal powders in a predetermined particle size range. a step of separating the remaining metal powder from the metal powder within the particle size range; The additive manufacturing device performs additive manufacturing using the metal powder having a predetermined particle size range obtained by the classification. The steps to The storage device stores metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification by the classifier. The remaining metal powder is reused by the powder manufacturing device to manufacture metal powder. a procedure for supplying the final product to the manufacturing equipment; A gas washer is used in the powder manufacturing apparatus and exhausted from the additive manufacturing apparatus. and cleaning the gas. a compressor compressing the cleaned gas; a tank storing the compressed gas; supplying gas from the tank to the powder manufacturing apparatus and the additive manufacturing apparatus; An additive manufacturing method comprising:

8. A procedure for producing metal powder by a powder production device using an inert gas; A classifier classifies the produced metal powder to obtain metal powders in a predetermined particle size range and metal powders in a predetermined particle size range. a step of separating the remaining metal powder from the metal powder within the particle size range; The additive manufacturing device performs additive manufacturing using the metal powder having a predetermined particle size range obtained by the classification. The steps to The storage device stores metal powders having particle sizes in the predetermined particle size range obtained as a result of classification by the classifier. The remaining metal powder is reused by the powder manufacturing device to manufacture metal powder. feeding the powder to a powder manufacturing device; A second classifier classifies the metal powder remaining after the additive manufacturing process in the additive manufacturing device, The metal powder is separated into a metal powder having a predetermined particle size range and the remaining metal powder other than the metal powder having the predetermined particle size range. The procedure and and The additive manufacturing device is configured to classify metal powder having a predetermined particle size range obtained by classification using the second classifier. Using the powder, additive manufacturing is carried out. The storage device stores the remaining metal powder other than the metal powder within the predetermined particle size range in the powder storage device. The powder is supplied to the powder manufacturing device so that the manufacturing device can reuse it to manufacture metal powder. Additive manufacturing methods.

9. A procedure for producing metal powder by a powder production device using an inert gas; A classifier classifies the produced metal powder to obtain metal powders in a predetermined particle size range and metal powders in a predetermined particle size range. a step of separating the remaining metal powder from the metal powder within the particle size range; The additive manufacturing device performs additive manufacturing using the metal powder having a predetermined particle size range obtained by the classification. The steps to The storage device stores metal powder other than the metal powder within the predetermined particle size range obtained as a result of classification by the classifier. The remaining metal powder is reused by the powder manufacturing device to manufacture metal powder. a procedure for supplying the final product to the manufacturing equipment; and The storage device stores the layered object manufactured by the layered manufacturing method in the layered manufacturing device. The cuttings cut out from the powder are reused by the powder manufacturing device to manufacture metal powder. Supply to the powder manufacturing equipment Additive manufacturing methods.

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