JP2023008448A - Laminate shaping system, and laminate shaping method - Google Patents

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

The present invention relates to a layered manufacturing system and a layered manufacturing method.

Metal lamination technology is being used in various fields, and it is possible to manufacture even complex shapes directly from drawings using metal powder as a raw material. It is mainly used for prototyping. In the powder bed method, which is currently the most popular method, a heat source such as a laser or an electron beam is applied to the metal powder that is spread all over the place. , perform beam irradiation. A three-dimensional shape is formed by repeating these processes. Instead of beam irradiation, there is also a type in which a cured resin is sprayed and solidified like an inkjet printer, and then heat-treated to form a modeled object.

One of the points is to spread the metal evenly, and for this reason, the metal powder used is required to be close to a true sphere and have a uniform particle size distribution. Although it depends on the equipment and material, there are examples where the electron beam type powder bed method recommends a particle size of about 40 to 150 μm, and the laser type recommends a particle size of about 20 to 50 μm.

The metal powder may be coarsened by bonding between particles after molding, or the metal once melted and scattered as spatter may reprecipitate as fine particles, and the particle size changes. Therefore, after molding, it is common to classify and exclude powders exceeding the particle size range to be used, and to reuse them. However, as the powder is repeatedly reused, its quality deteriorates due to surface oxidation. Therefore, when pursuing product quality, the number of times of reuse is limited, and powder that has been used more than a certain amount may be discarded.

As a method for producing metal powder, the plasma atomization method can produce high-quality powder with high sphericity, but it is expensive. The water atomization method is widely used as a low-cost method, but it is not suitable for additive manufacturing because the powder becomes amorphous. The most commonly used method is gas atomization, which involves blowing high-pressure gas onto molten metal to pulverize it.

JP 2018-145526 A

FIG. 12 is a graph showing an example of particle size measurement results of metal powder produced by the gas atomization method. As shown in FIG. 12, the produced metal powder has a broad particle size distribution. For additive manufacturing, it is necessary to classify the produced powder, and in some cases the yield is reduced to less than half. Thus, the additive manufacturing process increases manufacturing costs due to poor yields. In addition, since the metal powder used as the raw material is expensive, the molding cost increases.

Another feature of metal additive manufacturing is that a wide range of materials can be used because it uses powder as a raw material, but the types of commercially available raw materials are generally limited. If the original material is made to order, the raw material cost will increase further, and the powder excluded by the classification may become a large amount of waste because it is a made-to-order product and cannot be diverted to other uses. In this way, the use of the original material further increases the cost of the raw material powder, so there is a problem that it is difficult to adopt.

Thus, the increase in manufacturing cost has become a problem in the layered manufacturing process.

The present invention has been made in view of the above problem, and an object of the present invention is to provide a layered manufacturing system and a layered manufacturing method that make it possible to reduce the manufacturing cost in the layered manufacturing process.

A layered manufacturing system according to a first aspect of the present invention includes a powder manufacturing apparatus that manufactures metal powder using an inert gas, and classifies the manufactured metal powder into metal powder having a predetermined particle size range. A classifier that separates the remaining metal powders other than the metal powders having the predetermined particle size range, a layered manufacturing apparatus that performs layered manufacturing using the metal powders that have the predetermined particle size range obtained by the classification, and the Supplying the remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of classification in the classifier to the powder manufacturing apparatus so that the powder manufacturing apparatus can reuse the metal powder to manufacture the metal powder. a means;

According to this configuration, the metal powder produced by the powder production apparatus is classified, and the remaining metal powder outside the predetermined particle size range is reused as raw material powder for the powder production apparatus, thereby suppressing the generation of waste. and the manufacturing cost can be reduced.

In the above-described layered manufacturing system, the metal powder remaining after layered manufacturing in the layered manufacturing apparatus is classified into the 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 layered manufacturing apparatus further includes a second classifier for performing layered manufacturing using metal powder having a predetermined particle size range obtained by being classified by the second classifier, and the supply means includes: The remaining metal powder other than the metal powder having the predetermined particle size range may be supplied to the powder manufacturing apparatus so that the powder manufacturing apparatus can reuse the metal powder to manufacture the metal powder.

In the above-described layered manufacturing system, the supply means is arranged so that the powder manufacturing apparatus can reuse the facets cut from the layered product manufactured by the layered manufacturing in the layered manufacturing apparatus to manufacture the metal powder. You may supply to the said powder manufacturing apparatus.

A layered manufacturing system according to another aspect of the present invention includes: a first powder manufacturing apparatus that manufactures metal powder using gas; A first classifier that separates the remaining metal powders other than the metal powders having the predetermined particle size range, and a first classifier that laminates and molds the metal powders having the first particle size range obtained by the classification. A first production line having a layered manufacturing apparatus and a second production line that produces products of lower quality than the first production line, wherein the second powder that produces metal powder using gas a manufacturing apparatus, a second classifier for classifying the manufactured metal powder into metal powder having a second particle size range and remaining metal powder other than the metal powder having the predetermined particle size range; A second production line having a second layered manufacturing apparatus that performs layered manufacturing using the metal powder having the second particle size range obtained by classification, and the rest other than the metal powder having 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 apparatus so that the metal powder is reused in the second powder production apparatus. and a supply means for.

In the above-described layered manufacturing system, the supply means supplies the metal powder remaining after layered manufacturing in the first layered manufacturing apparatus to the second powder manufacturing apparatus so that the metal powder is reused in the second powder manufacturing apparatus. The supply means supplies the metal powder remaining in the layered manufacturing in the second layered manufacturing apparatus to the second powder manufacturing apparatus so that the metal powder is reused in the second powder manufacturing apparatus. You may supply to the powder manufacturing apparatus of 2.

In the above-described layered manufacturing system, the supply means supplies the facets cut out from the layered-molded article that has been layered-molded in the first layered-molding apparatus and the second layered-molding apparatus so that the metal powder is the It may be supplied to the second powder manufacturing apparatus so as to be reused in the second powder manufacturing apparatus.

A layered manufacturing method according to another aspect of the present invention includes a procedure in which a powder manufacturing apparatus manufactures metal powder using an inert gas, and a classifier classifies the manufactured metal powder to a predetermined particle size range. and the remaining metal powder other than the metal powder in the predetermined particle size range;
A procedure for additive manufacturing using a metal powder having a predetermined particle size range obtained by the classification by a layered manufacturing apparatus, and a metal powder having the predetermined particle size range obtained as a result of the classification by the classifier using the storage apparatus. and supplying the remaining metal powder other than the powder so that the powder manufacturing apparatus can reuse the metal powder to manufacture the metal powder.

According to one aspect of the present invention, the metal powder produced by the powder production apparatus is classified, and the remaining metal powder outside the predetermined particle size range is reused as raw material powder for the powder production apparatus, thereby reducing waste. The occurrence can be suppressed, and the modeling cost can be reduced.

It is a figure which shows the structure of the layered manufacturing system which concerns on 1st Embodiment. It is a schematic diagram which shows the layered manufacturing process which concerns on 1st Embodiment. It is a figure which shows an example of a structure of a powder manufacturing apparatus. It is a figure which shows an example of a structure of a lamination-molding apparatus. It is a figure which shows an example of a structure of the gas washer which uses an exhaust gas cleaning dry process. It is a figure which shows an example of an inert gas supply line. 1 is a diagram showing an example of a configuration of a gas washer using a wet exhaust gas cleaning process; FIG. It is a figure which shows the structure of the layered manufacturing system which concerns on 2nd Embodiment. It is a schematic diagram which shows the layered manufacturing process which concerns on 2nd Embodiment. It is a figure which shows the structure of the layered manufacturing system which concerns on 3rd Embodiment. It is a schematic diagram which shows the layered manufacturing process which concerns on 3rd Embodiment. 4 is a graph showing an example of particle size measurement results of metal powder produced by a gas atomization method. It is a schematic diagram which shows the lamination-molding process which concerns on a comparative example.

Hereinafter, each embodiment will be described with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art.

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

<First Embodiment>
On the other hand, in the first embodiment, both the powder manufacturing apparatus and the additive manufacturing apparatus are installed side by side in the metal powder manufacturing process that is the raw material for the metal additive manufacturing and the manufacturing process using the metal additive manufacturing. By classifying the metal powder manufactured by and reusing the remaining metal powder outside the predetermined particle size range as raw material powder for the powder manufacturing apparatus, the generation of waste is suppressed and the molding cost is reduced.

The use of a large amount of inert gas during manufacturing is also cited as a factor for the increase in manufacturing costs described above. A large amount of high-pressure gas is blown during powder production. Based on past achievements, about 20 kg of powder (converted to iron) can be produced with one liquefied argon (Ar) cylinder (capacity: 200 kg), and a large amount of inert gas is used.

Inert gas (for example, argon gas) is also used in the laser type powder bed system, which is currently the mainstream. In order to prevent the metal from oxidizing during melting, it is shaped while flowing an inert gas at a rate of several tens of liters/min. And since the modeling is repeated layer by layer, it takes hundreds of hours to model a large product, and a large amount of inert gas is required to complete the modeling. Moreover, when manufacturing a large amount of products, it is necessary to provide a plurality of modeling apparatuses. As a result, since it is necessary to supply a large amount of inert gas to each device, the amount of gas used is one of the factors that increase the running cost.

Considering the entire process from powder molding to product manufacturing, a large amount of inert gas is consumed throughout the process, which is one of the causes of increased molding costs. To solve this problem, in the additive manufacturing system according to the first embodiment, an inert gas (eg, argon Reuse of the inert gas reduces the manufacturing cost caused by the consumption of the inert gas.

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

<First Embodiment>
FIG. 1 is a diagram showing the configuration of a layered manufacturing system according to the first embodiment. As shown in FIG. 1, the layered manufacturing system S1 includes a powder manufacturing device 1, a classifier 2, a layered manufacturing device 3, a suction machine 4, a classifier 5 (also referred to as a second classifier), a gas A washing machine 6, a compressor 7, a compressor 7, a tank 8, and a supply means 90 are provided. The supply means 90 supplies the remaining metal powder other than the metal powder in the predetermined particle size range obtained as a result of classification in the classifier 2 so that the powder manufacturing apparatus 1 can reuse the metal powder to manufacture metal powder. The supply means 90 has a pipe P29 that connects the storage device 9, the storage device 9, and the classifier 2, for example.

Judging from the overall process, the amount of inert gas used during powder production and shaping has a significant impact on cost. Therefore, by installing a powder modeling device and a layered modeling device together, the argon gas can be reused and the cost of the entire process can be reduced.

Specifically, argon gas is used to cool the liquid metal during powder production, and the exhaust gas contains argon gas and metal powder. After recovering the raw material metal powder, fine particles that cannot be recovered by a filter or the like and are entrained in the gas are included as impurities. In the additive manufacturing, metal vapor volatilized by the beam is entrained in the gas as an impurity.

In order to remove these substances, the gas is cleaned by the gas washer 6, then the pressure is increased by the compressor 7, and the high pressure gas is stored in the tank 8. Gas is supplied from this tank 8 to the powder manufacturing apparatus 1 and the layered manufacturing apparatus 3 . By circulating the gas in this way, it is possible to suppress gas consumption and reduce running costs.

In addition, the manufactured powder is classified, and metal powder with a predetermined particle size range suitable for the purpose is used as a raw material for additive manufacturing. Waste of raw materials can be eliminated, and a production method with low environmental load can be provided throughout the process. Powders that are not suitable for additive manufacturing include large and small particles. Small particles are susceptible to dust explosion risk and deterioration due to surface oxidation. It is desirable to fill with an inert gas such as

In the current equipment, liquefied argon gas (capacity: 200 kg) is used, and about 20 kg of iron (Fe
) can melt the base alloy. For example, if the unit price of stainless steel is 1,000 yen/kg, the material cost for 20 kg is 20,000 yen, and the liquefied argon cylinder cost is 5.
Assuming that the cost is 3,000 yen and the yield is 50%, the raw material cost is 73,000 yen/10 kg to manufacture 10 kg of product. However, by making the argon gas and materials reusable, the necessary raw material cost will be 10,000 yen/10 kg, which will enable a significant cost reduction.

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

(Step S10) The components of the raw material and the recycled raw material obtained from the storage device 9 are adjusted.

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

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

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

(Step S50) Next, the suction machine 4 sucks the metal powder remaining after the lamination molding in the lamination molding apparatus 3, and the classifier 5 classifies the sucked metal powder to obtain particles having a predetermined particle size range. The metal powder and the remaining metal powder other than the metal powder having the predetermined particle size range are separated. As a result, the layered manufacturing apparatus 3 performs layered manufacturing again using the metal powder having a predetermined particle size range obtained by being classified by the classifier 5 . Moreover, the remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of classification in the classifier 5 is discarded.

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

(Step S70) The gas washer 6 cleans the gas after being used in the powder manufacturing apparatus 1 and the gas discharged from the laminate manufacturing apparatus.

(Step S80) Next, the compressor 7 compresses the cleaned gas.

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

(Step S100) The remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of the classification in the classifier 2 is recovered through the pipe P29, and the storage device 9 stores the metal powder in the powder manufacturing process. It is stored so that it can be reused by the apparatus 1 to manufacture metal powder. Then, the metal powder stored in the storage device 9 is supplied as a reusable raw material, adjusted with the raw material, and the adjusted raw material is supplied to the powder manufacturing apparatus 1 .

By installing the powder manufacturing apparatus 1 and the layered manufacturing apparatus 3 side by side, the argon gas recycling facility can be shared and the cost of the entire process can be reduced. Furthermore, metal powder has risks such as explosion and deterioration, and is not suitable for long-term storage. Therefore, it is possible to manufacture only the amount of metal powder required at that time by installing the apparatus side by side. This allows the storage volume to be minimized.

FIG. 3 is a diagram showing an example of the configuration of a powder manufacturing apparatus. As shown in FIG. 3, the powder manufacturing apparatus 1 includes a melting chamber 11 having a through hole in the bottom, a melting crucible 111 having a lower hole communicating with the through hole, and a melting chamber 11 under the melting chamber 11. and a gas pipe 113 inserted substantially horizontally in the upper part of the quenching chamber 112 . Further, the powder production apparatus 1 includes a first powder recovery box 12 communicating with the lower portion of the quenching chamber 112, a cyclone dust collector 13 communicating with the first powder recovery box 12, and a second powder recovery box communicating with the lower portion of the cyclone dust collector 13. 14. Further, the powder production apparatus 1 includes a dry filter 15 and a third powder recovery box 16 communicating with the lower portion of the dry filter 15 .

In the gas atomization method, the ingredients of the raw materials are adjusted so as to obtain the desired alloy composition, and the metal is melted in a vacuum by a method such as high-frequency induction heating. Molten metal is allowed to fall freely from a hole at the bottom of melting crucible 111, and the dropped molten metal is rapidly cooled by blowing high-pressure argon gas (an inert gas such as nitrogen can also be used) to form powder metal. The particle size distribution of the formed powder can be changed by the pressure of the gas and the method of spraying. The produced powder is recovered in the first powder recovery box 12 provided below the quenching chamber 112, and is transported to the subsequent stage by a high-pressure gas stream. Therefore, the powder is collected by the cyclone dust collector 13, the dry filter 15, etc., and the fine powder that cannot be collected by the dry filter 15 is discharged from the powder manufacturing apparatus 1 together with the argon gas.

The recovered metal powder is classified and adjusted to the desired particle size distribution. Since it takes time to classify fine particles, efficient operation is possible by adjusting the mesh size of the dry filter according to the purpose of use of the powder. For example, when a metal powder for an electron beam is required to have a particle size of 40 μm or more, an unnecessary particle size can be removed in advance by using a filter through which particles of 40 μm or less can pass.

FIG. 4 is a diagram illustrating an example of the configuration of a layered manufacturing apparatus. Here, the layered manufacturing apparatus 3 is, as an example, a laser type powder bed type metal layering apparatus. As shown in FIG. 4, the layered manufacturing apparatus 3 includes a layered manufacturing chamber 30 filled with argon gas, which is an example of an inert gas, a laser 31 provided in the layered manufacturing chamber 30, and a laser 31 that emits and a mirror 32 that reflects the laser light. The layered manufacturing apparatus 3 further includes a powder supply flattening plate 33 , a modeling stage 34 , powder supply containers 35 and 36 , and a powder suction nozzle 39 inserted into the layered manufacturing chamber 30 . Furthermore, the layered manufacturing apparatus 3 includes a switching valve 40, a pipe 41 having one end communicating with the layered manufacturing chamber 30 and the other end communicating with the switching valve 40, a pipe 42 having one end communicating with the switching valve 40, and a switching valve A pipe 43 communicating with 40 is provided.

In order to release the additive manufacturing chamber 30 for necessary preparations before manufacturing, the additive manufacturing chamber 30 is once evacuated and argon gas is flowed until the atmosphere is sufficiently replaced with argon gas before manufacturing. to start.

The additive manufacturing apparatus 3 causes the metal powder in the powder supply containers 35 , 36 to form a flat powder bed using the powder supply flattening plate 33 . The laser light controlled by the mirror 32 partially melts the metal powder on the build stage 34 to form a model 37 , leaving unmelted metal powder 38 around the model 37 . Since there is concern that some of the evaporated metals may re-deposit around this time, argon gas (or an inert gas such as nitrogen) is allowed to flow to remove these metal vapors, leaked air, and other impurities along with the argon gas. The gas containing the gas is discharged outside the system via the switching valve 40 . Before modeling, the switching valve 40 communicates the pipes 41 and 42, and these gases are discarded. On the other hand, during molding, the switching valve 40 is discharged to the pipe 41 and the gas washer 6 in order to clean the exhaust gas.

After the molding is finished, the unmelted metal powder 38 and surplus powder from forming the powder bed are collected by the suction machine 4 via the powder suction nozzle 39 and supplied to the classifier 5 . In FIG. 5, a first sieve 52 and a second sieve 53 located after the first sieve 52 and having a finer (dense) mesh than the first sieve 52 are provided. Of the powder collected from the suction machine 4, the powder that has passed through the first sieve 52 and has not passed through the second sieve 53 is returned to the powder supply containers 35, 36 and reused in the layered 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.

FIG. 5 is a diagram showing an example of the configuration of a gas washer using a dry exhaust gas cleaning process. As shown in FIG. 5 , the gas washer 6 includes a chamber 61 having an inertial dust collector 611 , a chamber 62 communicating with the chamber 61 and having a dry filter 621 , and a blower 63 communicating with the chamber 62 . Further, the gas washer 6 includes an activated carbon filter 64, adsorption tanks 65 and 66, a pipe P61 whose one end communicates with the activated carbon filter 64, and branch pipes P62 and P63 bifurcated from the pipe P61. The adsorption tanks 65 and 66 are filled with zeolite A, for example. The branch pipe P62 has one end communicating with the pipe P61 and the other end communicating with the adsorption tank 65, and is provided with a valve B62. On the other hand, the branch pipe P63 has one end communicating with the pipe P61 and the other end communicating with the adsorption tank 66, and is provided with a valve B63. Further, the gas washer 6 includes a vacuum pump 67, a pipe P64 having one end communicating with the adsorption tank 65 and the other end communicating with the vacuum pump 67, a valve B61 provided in the pipe P64, and an adsorption tank 66 having one end. and the other end of which communicates with a vacuum pump 67, and a valve B64 provided on the pipe P65.

The chamber 61 is supplied with the inert gas (eg, argon gas here) used for metal powder production from the powder production apparatus 1 . Similarly, the chamber 61 is supplied with the inert gas (eg, argon gas) used for metal additive manufacturing from the additive manufacturing apparatus 3 .

Within chamber 61 , an inertial dust collector 611 , such as a cyclone, collects large particles from these supplied inert gases and the remaining gas is discharged into chamber 62 . Within chamber 62, a dry filter 621, such as a bag filter, collects particulates from this remaining gas. At this time, if the pressure loss of the dry filter 621 makes it difficult for the gas to pass through, the blower 63 is provided to promote the gas flow. The gas that has passed through the dry filter 621 is discharged by the blower 63, and then the impurities are removed by the activated carbon filter 64, the adsorption tanks 65 and 66, and the like. In order to enable continuous operation, a plurality of adsorption tanks such as adsorption tanks 65 and 66 are provided in parallel. , to regenerate the adsorption tanks of the series that do not pass gas.

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 is divided into a branch pipe P71 and a branch pipe P72. The 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 (for example, argon or nitrogen) discharged from the adsorption tanks 65 and 66 is supplied to the compressor 7 and compressed to be pressurized.

A discharge port of the compressor 7 is connected to one end of the pipe P73, the other end of the pipe P73 is connected to the tank 8, and the pipe P73 is provided with a valve B73. Thereby, the inert gas compressed by the compressor 7 is supplied to the tank 8 and stored.

One end of a pipe P<b>80 is connected to the tank 8 , and the other end of the pipe P<b>80 is connected to the gas concentration system 73 . Thereby, the concentration of the gas discharged from the tank 8 is measured. Further, a branch pipe P91 and a branch pipe P92 branching from the middle of the pipe P90 are provided. A flow meter 71 and a valve B81 are provided in this branch pipe P91, and communicates with the powder manufacturing apparatus 1. A flow meter 72 and a valve B82 are provided in this branch pipe P92, and communicates with the laminate molding apparatus 3. Thereby, the inert gas stored in the tank is supplied to the powder manufacturing apparatus 1 and the layered manufacturing apparatus 3 at a required flow rate.

As described above, the additive manufacturing system S1 according to the present embodiment includes the powder manufacturing apparatus 1 that manufactures metal powder using an inert gas, and classifies the manufactured metal powder into metal powder having a predetermined particle size range. A classifier 2 that separates the remaining metal powders other than the metal powders having the predetermined particle size range, and a layered manufacturing apparatus 3 that performs layered manufacturing using the metal powders having the predetermined particle size range obtained by the classification. , the remaining metal powder other than the metal powder in the predetermined particle size range obtained as a result of the classification by the classifier 2 is supplied to the powder manufacturing apparatus 1 so as to be reused to manufacture the metal powder. , provided.

According to this configuration, the metal powder produced by the powder production apparatus is classified, and the remaining metal powder outside the predetermined particle size range is reused as raw material powder for the powder production apparatus, thereby suppressing the generation of waste. and the manufacturing cost can be reduced.

In addition, the laminate manufacturing system S2 according to the present embodiment includes a gas washer 6 that cleans the gas after being used in the powder manufacturing apparatus 1 and the gas discharged from the laminate manufacturing apparatus 3, and a gas cleaner 6 that compresses the gas after cleaning. A compressor 7 and a tank 8 for storing the compressed gas are provided, and the gas is supplied from the tank 8 to the powder manufacturing apparatus 1 and the laminate molding apparatus 3 .

According to this configuration, the gas after being used in the powder manufacturing apparatus 1 and the gas discharged from the layered manufacturing apparatus 3 can be reused, so gas consumption can be suppressed and running costs can be reduced. .

<Modification of First Embodiment>
The gas washer is not limited to using a dry process for cleaning exhaust gas, and may be a wet process for cleaning exhaust gas. If the metal vapor discharged from the layered manufacturing apparatus adheres to any part in the system and leads to troubles, it is desirable to employ wet gas cleaning using a scrubber or the like. Metal vapor can be cooled by water, precipitated and removed, and can be reliably removed by a scrubber. In the latter stage, it is desirable to dehumidify the gas with a dehumidifier or the like in order to remove a large amount of water contained in the gas.

FIG. 7 is a diagram showing an example of the configuration of a gas washer using a wet exhaust gas cleaning process. As shown in FIG. 7, the gas washer 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 an adsorption A bath tank 86, 87 is provided.
Further, the gas washer 6b includes a pipe P81, one end of which communicates with the activated carbon filter 85, and branch pipes P82 and P83 bifurcated from the pipe P81. The adsorption tanks 86 and 87 are filled with zeolite A, for example. The branch pipe P82 has one end communicating with the pipe P81 and the other end communicating with the adsorption tank 86, and is provided with a valve B82. On the other hand, the branch pipe P83 has one end communicating with the pipe P81 and the other end communicating with the adsorption tank 87, and is provided with a valve B83. Further, the gas washer 6b includes a vacuum pump 88, a pipe P84 having one end communicating with the adsorption tank 86 and the other end communicating with the vacuum pump 88, a valve B81 provided on the pipe P84, and an adsorption tank 87 at one end. and the other end of which communicates with a vacuum pump 88, and a valve B84 provided on the pipe P85.

The water scrubber 80 has a chamber 81 supplied with spent gas and a pump 82 communicating with the chamber, the chamber 81 having a filler 811 and spaced above the filler 811 . and a tube 812 . A plurality of holes are provided in the lower portion of the pipe 812 , and water supplied from the pump 82 is discharged from the plurality of holes in the lower portion of the pipe 812 . This allows the metal vapor to be cooled by water, precipitated and removed, and can be reliably removed by the scrubber. After that, the discharged gas is dehumidified in the dehumidifier 83 to remove a large amount of water contained in the gas. After passing through the dehumidifier 83, the gas is discharged by the blower 63, and then impurities are removed by the activated carbon filter 85, the adsorption tanks 86 and 97, and the like.

<Second embodiment>
In the first embodiment, the powder used in additive manufacturing is collected and then classified, and metal powder outside a predetermined particle size range, such as granulated powder, is removed and reused in manufacturing. Therefore, compared to general methods such as casting and cutting, the yield of raw materials is high and the environmental load is excellent. On the other hand, the metal powder outside the predetermined particle size range after being classified after the layered manufacturing is discarded. Moreover, in the post-process, the removed support members and cut chips from the finishing process are also generated, and these are disposed of as waste. These points impose an environmental load, and it is desired to further reduce the environmental load. In response to this problem, in the second embodiment, these wastes are also collected and reused as raw materials in the powder manufacturing apparatus, thereby reducing the molding cost and further preventing the generation of wastes. It is possible to further reduce the environmental load.

FIG. 8 is a diagram showing the configuration of a layered manufacturing system according to the second embodiment. FIG. 9 is a schematic diagram showing a layered manufacturing process according to the second embodiment. As shown in FIGS. 8 and 9, compared to the laminate manufacturing system S1 according to the first embodiment in FIG. 1, the laminate manufacturing system S2 according to the second embodiment has a predetermined The difference is that the remaining metal powder other than the metal powder within the particle size range is collected and stored in the storage device 9 (see step S150 in FIG. 9). Furthermore, the difference is that the cut pieces discharged by cutting the laminate-molded article modeled by laminate-molding in the laminate-molding apparatus 3 are collected and stored in the storage device 9 (see step S160 in FIG. 9). As a result, the remaining metal powders and cut pieces stored in the storage device 9 are adjusted together with the raw materials as reusable raw materials, and the raw materials after the component adjustment are supplied to the powder manufacturing device 1 (step S200 in FIG. 9). reference).

Note that steps S110 to S140 in FIG. 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.

<Third Embodiment>
Next, a third embodiment will be described. Recovered recycled raw materials contain more impurities than new raw materials due to surface oxidation of powder and oxidation due to heat during cutting, and their quality may deteriorate.
On the other hand, typical applications for additive manufacturing include fields that require strict quality control, such as medical care, which requires custom-made products, and aerospace, where there is a strong demand for weight reduction due to complex structures. On the other hand, in fields that take advantage of rapid manufacturing, development prototypes are the main applications. It is sufficient to confirm the shape and basic performance of the development prototype, and in most cases the material quality is not an issue.

Therefore, in the third embodiment, the characteristics of layered manufacturing are reflected, and a production line is constructed according to the application. This facilitates reuse of raw materials. In other words, products that require high quality use powders made from raw materials with few impurities in the first production line, and do not reuse or minimize the reuse of powder raw materials during additive manufacturing. This makes it possible to keep the product quality high. On the other hand, surplus raw materials can be used without waste by using recycled raw materials in the second production line for manufacturing development prototypes and the like. Thereby, the manufacturing cost can be reduced.

An example of the layered manufacturing system according to the third embodiment will be described below with reference to FIGS. 10 and 11. FIG. FIG. 10 is a diagram showing the configuration of a layered manufacturing system according to the third embodiment. FIG. 11 is a schematic diagram showing a layered manufacturing process according to the third embodiment.

As shown in FIG. 10, the layered manufacturing system S3 according to the third embodiment includes a first production line L1, a second production line L2, and supply means 90b. The supply means 90b comprise, for example, a storage device 9. FIG. The first production line L1 includes a powder manufacturing device 1a (also referred to as a first powder manufacturing device) to which raw materials after component adjustment from raw materials are supplied, and a classifier 2a (also referred to as a first classifier). , and a laminate molding apparatus 3a (also referred to as a first laminate molding apparatus). The second production line L2 includes a powder production device 1b (also referred to as a second powder production device) to which the raw material and the recycled raw material are adjusted in composition, and a classifier 2b (second classifier). machine), a layered manufacturing apparatus 3b (also referred to as a third layered manufacturing apparatus), a suction machine 4, and a classifier 5. Here, the reusable raw material is supplied from the storage device 9 . In the storage device 9, the remaining metal powder other than the metal powder having a predetermined particle size range is collected by the classifier 2a and stored, and the remaining metal powder after the layered manufacturing is collected by the layered manufacturing device 3a and stored. , Kiriko is supplied from post-processing and stored.

Next, a layered manufacturing method according to the third embodiment will be described with reference to FIG. 11 .

(Step S310) Components are adjusted using raw materials.

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

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

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

(Step S410) The ingredients of the raw material and the reusable raw material acquired from the storage device 9 are adjusted.

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

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

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

(Step S450) Next, the suction machine 4 sucks the metal powder remaining after the layered manufacturing in the layered manufacturing apparatus 3b, and the classifier 5 classifies the sucked metal powder to obtain particles having a predetermined particle size range. The metal powder and the remaining metal powder other than the metal powder having the predetermined particle size range are separated. As a result, the layered manufacturing apparatus 3b performs layered manufacturing again using the metal powder having a predetermined particle size range obtained by being classified by the classifier 5 . Moreover, the remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of classification in the classifier 5 is discarded.

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

(Step S500) The remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of classification by the classifier 2a in step S330 is collected and stored in the storage device 9. Further, in step S340, the remaining metal powder after layered manufacturing is collected and stored in the storage device 9. FIG. Also, the remaining metal powder after being classified in step S340 is collected and stored in the storage device 9. FIG. Further, the remaining metal powder after being classified in step S450 is collected and stored in the storage device 9. FIG. The cut pieces obtained by cutting in step S460 are collected in step S500 and stored in the storage device 9. FIG. Then, the metal powder stored in the storage device 9 is supplied as a reusable raw material, adjusted with the raw material, and the adjusted raw material is supplied to the powder manufacturing apparatus 1b.

As described above, the additive manufacturing system S3 according to the third embodiment includes the powder manufacturing apparatus 1a that manufactures metal powder using gas, and classifies the manufactured metal powder into metal powder having a first particle size range. A classifier 2a that separates the remaining metal powders other than the metal powders having the predetermined particle size range, and a layered manufacturing apparatus 3a that performs layered manufacturing using the metal powders having the first particle size range obtained by the classification. A first production line L1 having
Furthermore, the laminate manufacturing system S3 is a second production line L2 that produces products of lower quality than the first production line L1, and includes a powder production device 1b that produces metal powder using gas, and the production a classifier 2b for classifying the obtained metal powder 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; 2, a second production line L2 having a layered manufacturing apparatus 3b that performs layered manufacturing using metal powder having a particle size range of No. 2.
Furthermore, the additive manufacturing system S3 processes 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. A supply means 90b is provided to supply the powder production apparatus 1b for reuse in 1b.

According to this configuration, it is possible to use powders manufactured from raw materials with few impurities in the first production line, and not to reuse or to minimize the reuse of powder raw materials during additive manufacturing. This makes it possible to maintain high product quality in the first production line L1. On the other hand, by reusing the remaining metal powder in the first production line L1 and the second production line L2 in the second production line, the production cost of the products in the second production line L2 can be reduced. .

In addition, in the layered manufacturing system S3 according to the third embodiment, the supply means 90b reuses the metal powder remaining after the layered manufacturing in the layered manufacturing apparatus 1a in the second powder manufacturing apparatus 1b. It is supplied to the powder manufacturing apparatus 1b as follows. In addition, the supply means 90b feeds the metal powder remaining after the layered manufacturing in the layered manufacturing apparatus 3b (specifically, for example, the remaining powder other than the reused powder discharged from the classifier 5) to the powder manufacturing apparatus 1b. supplied to the second powder production apparatus so as to be reused in .

Thus, by reusing the metal powder, it is possible to reduce the manufacturing cost of the products in the second manufacturing line L2.

In addition, the supply means 90b feeds the facets cut out from the laminate-molded objects that are formed by the laminate-molding in the laminate-molding apparatus 3a and the laminate-molding apparatus 3b so that the metal powder can be reused in the powder-manufacturing apparatus 1b. It feeds the device 1b. Thereby, the metal powder can be reused further, and the manufacturing cost of the products in the second manufacturing line L2 can be reduced.

Note that the laminate manufacturing system S3 according to the third embodiment may further include the gas washer 6, the compressor 7, and the tank 8 as in the first and second embodiments. Thereby, the gas discharged from the powder manufacturing apparatus 1a, the layered manufacturing apparatus 3a, the powder manufacturing apparatus 1b, and the layered manufacturing apparatus 3b can be reused.

As described above, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the present invention at the implementation stage. Further, various inventions can be formed by appropriate combinations of the plurality of constituent elements disclosed in the above embodiments. For example, some components may be omitted from all components shown in the embodiments. Furthermore, components across different embodiments may be combined as appropriate.

1, 1a, 1b powder production device 11 melting chamber 111 melting crucible 112 quenching chamber 113 gas pipe 12 first powder recovery box 13 cyclone dust collector 14 second powder recovery box 15 dry filter 16 third powder recovery box 2a, 2b classifier 3 Layered manufacturing apparatus 30 Layered manufacturing chamber 31 Laser 32 Mirror 33 Powder supply flattening plate 34 Modeling stages 35, 36 Powder supply container 39 Powder suction nozzle 40 Switching valves 41, 42, 43 Pipe 5 Classifier 52 First sieve 53 2 sieves 6, 6b Gas washer 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 bath tank 88 vacuum pump S1, S2, S3 layered manufacturing system

Claims (8)

a powder manufacturing device for manufacturing metal powder using an inert gas;
a classifier for classifying the manufactured metal powder into metal powder having a predetermined particle size range and remaining metal powder other than the metal powder having the predetermined particle size range;
A layered molding apparatus that performs layered molding using the metal powder having a predetermined particle size range obtained by the classification;
The remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of the classification by the classifier is supplied to the powder manufacturing apparatus so that the powder manufacturing apparatus can reuse the metal powder to manufacture the metal powder. a supply means;
Additive manufacturing system with. a gas washer for cleaning the gas after being used in the powder manufacturing apparatus and the gas discharged from the layered manufacturing apparatus;
a compressor for compressing the cleaned gas;
a tank for storing the compressed gas;
with
The additive manufacturing system according to claim 1, wherein gas is supplied from the tank to the powder manufacturing apparatus and the additive manufacturing apparatus. a second classifier that classifies the metal powder remaining after the layered manufacturing in the layered manufacturing apparatus into metal powder having a predetermined particle size range and remaining metal powder other than the metal powder having the predetermined particle size range; further prepared,
The layered manufacturing apparatus performs layered manufacturing using metal powder having a predetermined particle size range obtained by classifying with the second classifier,
2. The supply means supplies the remaining metal powder other than the metal powder having the predetermined particle size range to the powder manufacturing apparatus so that the powder manufacturing apparatus can reuse the metal powder to manufacture the metal powder. 3. The laminate manufacturing system according to 2. The supply means supplies the powder manufacturing apparatus with the facets cut out from the laminate-molded article that is formed by the laminate molding in the laminate molding apparatus so that the powder manufacturing apparatus can reuse the cut face to manufacture the metal powder. The layered manufacturing system according to any one of claims 1 to 3. a first powder production apparatus for producing metal powder using a gas; and classifying the produced metal powder into metal powder having a first particle size range and remaining metal powder other than the metal powder having a predetermined particle size range. A first production line having a first classifier for classifying into metal powders and a first additive manufacturing apparatus for additively manufacturing using the metal powders obtained by the classification and having the first particle size range; ,
A second production line for producing products of lower quality than the first production line, comprising: a second powder production apparatus for producing metal powder using gas; and classifying the produced metal powder. a second classifier that separates the metal powder into the metal powder of the second particle size range and the remaining metal powder other than the metal powder of the predetermined particle size range; and the second particle size range obtained by the classification. A second production line having a second additive manufacturing apparatus for additive manufacturing using the metal powder of
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 are reused in the second powder production apparatus. a supply means for supplying the second powder production apparatus so that
Additive manufacturing system with. The supply means supplies the metal powder remaining after layered manufacturing in the first layered manufacturing apparatus to the second powder manufacturing apparatus so that the metal powder is reused in the second powder manufacturing apparatus. ,
The supply means supplies the metal powder remaining after layered manufacturing in the second layered manufacturing apparatus to the second powder manufacturing apparatus so that the metal powder is reused in the second powder manufacturing apparatus. The additive manufacturing system according to claim 5. The supply means supplies the metal powder to the facets cut out from the laminate-molded article that has been modeled by the laminate-molding in the first laminate-molding apparatus and the second laminate-molding apparatus. The layered manufacturing system according to claim 5 or 6, supplied to the second powder manufacturing apparatus so as to be reused. A procedure in which the powder production apparatus produces metal powder using an inert gas;
a step of classifying the manufactured metal powder by a classifier into a metal powder having a predetermined particle size range and remaining metal powder other than the metal powder having a predetermined particle size range;
A procedure for lamination-molding using the metal powder having a predetermined particle size range obtained by the classification by the lamination-molding apparatus;
a step in which the storage device supplies the remaining metal powder other than the metal powder having the predetermined particle size range obtained as a result of classification in the classifier so that the powder production device reuses the remaining metal powder to produce metal powder; ,
A layered manufacturing method comprising:

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