JP2018103463A - Molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding device capable of supplying gas at amount needed in a chamber while maintaining absorption performance of an absorber in a molding device having the absorber for absorbing oxygen or steam.SOLUTION: A molding device 1 has a discharge port 31 for discharging gas for removing fume into a chamber 20a, a suction port 41 for sucking the gas in the chamber 20a, an absorber 70 for absorbing at least one of oxygen or steam contained in the gas, a plurality of circuits for communicating the discharge port 31 and the suction port 41 and circulating the gas from the suction port 41 to the discharge port 31 and including a first branch passage 53 in which the absorber 70 is arranged and a second branch passage 54 in which no absorber 70 is arranged, and a flow rate adjustment part for adjusting amount of the gas passing the first branch passage 53 and amount of the gas passing the second branch passage 54.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a modeling apparatus.

  As described in Patent Document 1, a modeling apparatus that manufactures a three-dimensional structure by irradiating a powder material with a laser is known. This modeling apparatus manufactures a three-dimensional structure by irradiating each layer corresponding to each cross-sectional area of the three-dimensional structure with a laser and solidifying sequentially.

  In such a modeling apparatus, when a powdered material is irradiated with a laser, a smoke-like substance called fume (referred to as dust, fumes, steam, volatile particles generated by heating or sublimation of the powdered material) is irradiated. Arising from. Therefore, in the modeling apparatus described in Patent Document 2, in order to prevent the generated fumes from rising and blocking the laser path, thereby reducing the laser irradiation amount, the chamber is prevented from blocking the laser path. The gas is flowing locally inside. And a modeling apparatus provides a filter in the circulation path which attracts | sucks gas from the inside of a chamber, and supplies gas in a chamber, and reproduces | regenerates gas by removing the fumes contained in gas with the said filter.

Special table 2011-526222 gazette International Publication No. 2011/049143

  By the way, the modeling apparatus may be provided with an adsorption device that adsorbs oxygen and water vapor contained in the gas. While such an adsorption device adsorbs oxygen and water vapor contained in the gas, it releases the adsorbed oxygen and water vapor to, for example, the atmosphere at an appropriate timing. However, the adsorption capacity of the adsorption device for oxygen and water vapor is limited. For this reason, when the supply amount of gas into the chamber increases, the adsorption capacity of the adsorption device may reach its limit before releasing oxygen or water vapor. On the other hand, if the supply amount of the gas supplied into the chamber is limited so that the adsorption capacity does not reach the limit, the amount of gas necessary for fume removal cannot be supplied into the chamber.

  The present invention has been made in view of such circumstances, and the object thereof is a modeling apparatus equipped with an adsorption device that adsorbs oxygen and water vapor, while maintaining the adsorption capability of the adsorption device, and is necessary in the chamber. An object of the present invention is to provide a modeling apparatus capable of supplying an amount of gas.

  A modeling apparatus that solves the above problem is a modeling apparatus that manufactures a three-dimensional structure by repeating a process of partially solidifying the powder layer by irradiating a powder layer made of a powdery material with a laser. A discharge port for discharging a gas for removing fumes into the chamber, a suction port for sucking the gas in the chamber, and an adsorption device for adsorbing at least one of oxygen and water vapor contained in the gas; A circulation path that connects the discharge port and the suction port and circulates the gas from the suction port to the discharge port, the first circulation path provided with the adsorption device, and the adsorption device provided A plurality of circulation paths including a second circulation path that is not provided, a flow rate adjusting unit that adjusts the amount of the gas passing through the first circulation path and the amount of the gas passing through the second circulation path And comprising.

  According to the above configuration, the flow rate adjustment unit supplies the necessary amount of gas into the chamber while limiting the amount of gas passing through the first circulation path so that the adsorption capacity of the adsorption device does not reach the limit. Thus, the amount of gas passing through the second circulation path can be adjusted. As a result, it is possible to supply a necessary amount of gas into the chamber while maintaining the adsorption capability of the adsorption device.

In the modeling apparatus, the maximum flow rate of the second circulation path is preferably the same as or higher than the flow rate of the gas that needs to be discharged into the chamber.
According to the above configuration, for example, even if the flow rate of the gas passing through the first circulation path is reduced or zero, a necessary amount of gas can be supplied into the chamber by the gas passing through the second circulation path. it can.

  In the modeling apparatus, it is preferable that a filter that removes fine powder contained in the gas when the gas passes is provided upstream of the adsorption device in the first circulation path.

  According to the said structure, after passing the filter which removes a fine powder, since gas passes an adsorption | suction apparatus, it can suppress that a fine powder enters into an adsorption apparatus.

  According to the present invention, in a modeling apparatus including an adsorption device that adsorbs oxygen and water vapor, a necessary amount of gas can be supplied into the chamber while maintaining the adsorption capability of the adsorption device.

The figure which shows the schematic structure in one Embodiment of a modeling apparatus. The block diagram which shows the electrical structure of the modeling apparatus of the embodiment. It is a timing chart which shows operation | movement of the modeling apparatus of the embodiment, (a) is a figure which shows the change of oxygen concentration, (b) is a figure which shows operation | movement of a 1st switching valve, (c) is a 2nd switching valve. The figure which shows operation | movement of (d), The figure which shows operation | movement of the on-off valve of an adsorption | suction apparatus. The flowchart which shows control of the modeling apparatus of the embodiment. The flowchart which shows control of the modeling apparatus of the embodiment. The figure which shows the circulation path of the modeling apparatus of the embodiment. The figure which shows the circulation path of the modeling apparatus of the embodiment. The figure which shows the circulation path of the modeling apparatus of the embodiment. The figure which shows the modification of the circulation path of a modeling apparatus. The figure which shows the modification of the circulation path of a modeling apparatus. The figure which shows the modification of the circulation path of a modeling apparatus. The figure which shows the modification of the circulation path of a modeling apparatus.

Hereinafter, an embodiment of a modeling apparatus will be described with reference to FIGS.
First, the schematic configuration of the modeling apparatus will be described with reference to FIG.
As shown in FIG. 1, the modeling apparatus 1 includes a modeling unit 20 that models a three-dimensional object, a fume removal flow forming unit 26 that supplies an inert gas to the modeling unit 20, and oxygen and water vapor from the circulated gas. And an adsorption device 70 for adsorbing. The interior of the modeling unit 20 (hereinafter referred to as “chamber 20a”) is filled with an inert gas. Ar gas is used as the inert gas. The fume removal flow is a flow for removing fume and includes a concept called a laminar flow.

  The modeling unit 20 includes a container 21 having a modeling table 22 that supports a three-dimensional modeled object O to be modeled, and a recoater 24 that laminates a powder layer 25 made of a powder material M on the modeling table 22 with a predetermined thickness. And a laser irradiation unit 10 that irradiates the powder layer 25 on the modeling table 22 with laser light.

  The modeling table 22 of the container 21 can be moved up and down, and descends one layer each time the powder layer 25 is further solidified. On the upper surface of the modeling table 22, a modeling plate 23 serving as a mounting table for the three-dimensional model O is installed.

  Each time the powder layer 25 is further solidified, the recoater 24 stacks the powder layer 25 on the modeling plate 23 by a thickness corresponding to one layer. The surface of the powder layer 25 laminated on the modeling table 22 (modeling plate 23) on the laser irradiation unit 10 side is a laser irradiation surface 25a on which a laser is irradiated.

  The laser irradiation unit 10 irradiates a laser beam emitted from a laser oscillator (not shown) with a scanning system such as a galvanometer mirror to a desired position on the laser irradiation surface 25a of the powder layer 25.

  The fume removal flow forming unit 26 supplies new inert gas into the chamber 20a and circulates the inert gas supplied into the chamber 20a. The fume removal flow forming unit 26 includes the circulation path 50 for circulating the inert gas as described above.

  The fume removal flow forming unit 26 has a discharge unit 30 having a plurality of discharge ports 31 for discharging an inert gas for removing fumes in the chamber 20a, and a plurality of suction units for sucking the inert gas discharged from the discharge ports 31. And a suction part 40 having a suction port 41. The fume removal flow forming unit 26 forms a fume removal flow F along the laser irradiation surface 25 a above the powder layer 25 by the gas discharged from the plurality of discharge ports 31. The fume removal flow F is a gas flow formed in a layered shape above the powder layer 25 along the laser irradiation surface 25a.

  The circulation path 50 includes a first path 51 from the discharge port 31 through the chamber 20a to the suction port 41, and a second path 52 from the suction port 41 to the discharge port 31 through the outside of the chamber 20a. Yes. The second path 52 is a circulation path that connects the suction port 41 and the discharge port 31 and circulates the inert gas from the suction port 41 to the discharge port 31.

  A fine powder removal filter 58 for removing fine powder and the like contained in the inert gas is provided downstream of the suction port 41 of the second path 52. The fine powder removal filter 58 has a blower 59, and an inert gas is sent into the fine powder removal filter 58 by the blower 59. Thus, by removing the fine powder and the like before the inert gas is introduced into the adsorption device 70, clogging and the like in the adsorption device 70 can be suppressed, and the replacement frequency of the filter and the like can be reduced.

  The second path 52 has a branch path branched downstream of the fine powder removal filter 58 and joins upstream of the discharge port 31. The branch path includes a first branch path 53 corresponding to a first circulation path provided with the adsorption device 70 and a second branch path 54 corresponding to a second circulation path not provided with the adsorption device 70. ing.

  A blower 61 is installed upstream of the adsorption device 70 in the first branch 53. The blower 61 is for making up for the flow rate that decreases when the gas is passed through the adsorption device 70. A first switching valve 62 and a first flow meter 63 are installed in this order downstream of the adsorption device 70 in the first branch path 53. The first switching valve 62 is, for example, a butterfly valve, and can change the flow rate of the inert gas passing through the first branch path 53 and close the first branch path 53 according to an instruction from the outside. The first flow meter 63 is a flow meter such as a diaphragm or an ultrasonic type, and measures and outputs the flow rate of the inert gas flowing through the first branch path 53. The flow rate measured by the first flow meter 63 is indicated as Q1.

  The second branch 54 is not provided with the adsorption device 70, and is installed from the upstream side in the order of the second switching valve 64 and the second flow meter 65. The second switching valve 64 is, for example, a butterfly valve, and can change the flow rate of the inert gas passing through the second branch path 54 and close the second branch path 54 according to an instruction from the outside. The second flow meter 65 is a flow meter such as a diaphragm or an ultrasonic type, and measures and outputs the flow rate of the inert gas flowing through the second branch 54. The flow rate measured by the second flow meter 65 is indicated as Q2. The maximum flow rate of the second branch 54 is the same as or higher than the flow rate of the gas that needs to be discharged into the chamber 20a.

  A third flow meter 66 is installed between the discharge port 31 and a portion where the first branch path 53 and the second branch path 54 of the second path 52 merge. The third flow meter 66 is a diaphragm or ultrasonic flow meter, and the flow rate of the inert gas that flows downstream of the portion where the first branch 53 and the second branch 54 of the second path 52 merge. Is measured and output. The flow rate measured by the third flow meter 66 is indicated as Q3.

  The adsorption device 70 includes an oxygen adsorption unit 71 that reduces the concentration of oxygen contained in the inert gas that passes through the first branch path 53. The oxygen adsorption part 71 has a catalyst that adsorbs oxygen. Note that the oxygen adsorption unit 71 may be provided with two systems so that they can be used continuously by performing regeneration alternately. In addition, the adsorption device 70 includes a water vapor adsorption unit 72 that reduces the concentration of water vapor contained in the inert gas that passes through the first branch path 53. The water vapor adsorption unit 72 has a filter including a hollow fiber membrane that removes water vapor and a filter including silica gel that adsorbs water vapor. It should be noted that the water vapor adsorption unit 72 may be provided with two systems so that they can be used continuously by performing regeneration alternately. The adsorption device 70 adsorbs oxygen and water vapor contained in the inert gas, while releasing the adsorbed oxygen and water vapor, for example, into the atmosphere at an appropriate timing.

  The adsorption device 70 includes an inlet 70a through which an inert gas flows and an outlet 70b through which the inert gas flows out. The inflow port 70a is provided with a first on-off valve 73 that is an inflow side valve for opening and closing the inflow port 70a. The first on-off valve 73 is a two-position electromagnetic valve, which is normally closed and opened when energized. The outflow port 70b is provided with a second on-off valve 74 that is an outflow side valve for opening and closing the outflow port 70b. The second on-off valve 74 is a two-position solenoid valve, which is normally closed and opened when energized.

  A supply unit 75 that supplies new inert gas is provided upstream of the discharge port 31 of the second path 52. The supply unit 75 introduces a new inert gas from the tank 76 into the second path 52 by a certain amount while the modeling apparatus 1 is operating.

  Above the powder layer 25, a fume removal flow F is formed by the fume removal flow forming unit 26. The height and width of the fume removal flow F can be arbitrarily set, and are determined by a modeling material, a modeling method, and the like. The fume removal flow F is preferably formed at a height including the height at which the spatter is scattered.

  The discharge port 31 and the suction port 41 are disposed in the discharge unit 30 and the suction unit 40 in such a manner as to face each other at a position sandwiching the powder layer 25. The discharge part 30 and the suction part 40 are respectively arranged on the opposite side walls 20b of the chamber 20a.

Next, the electrical configuration of the modeling apparatus 1 will be described with reference to FIG.
As illustrated in FIG. 2, the modeling apparatus 1 includes a control unit 80 that controls the modeling apparatus 1. The control unit 80 controls the container 21, the recoater 24, and the laser irradiation unit 10 to form the three-dimensional structure O, and performs control for circulating an inert gas in the chamber 20 a. In FIG. 2, the configuration related to the modeling of the three-dimensional structure O itself is omitted. The control unit 80, the first switching valve 62, and the second switching valve 64 function as a switching unit, and also function as a flow rate adjusting unit.

  An oxygen sensor 81 and a water vapor sensor 82 are provided in the chamber 20a. The oxygen sensor 81 measures the oxygen concentration in the chamber 20 a and outputs the measurement result to the control unit 80. The water vapor sensor 82 measures the water vapor concentration in the chamber 20 a and outputs the measurement result to the control unit 80. Further, the first flow meter 63, the second flow meter 65, and the third flow meter 66 measure the flow rate and output the measurement result to the control unit 80.

  The control unit 80 adjusts the flow rate of the inert gas passing through the first branch path 53 by controlling the opening degree of the first switching valve 62 of the first branch path 53. The control unit 80 adjusts the flow rate of the inert gas passing through the second branch path 54 by controlling the opening degree of the second switching valve 64 of the second branch path 54. In addition, the control unit 80 switches between opening and closing by controlling the first on-off valve 73 and the second on-off valve 74 provided in the adsorption device 70. The first on-off valve 73 and the second on-off valve 74 are opened and closed in the same manner to suppress unnecessary entry of the inert gas into the adsorption device 70. Therefore, the control unit 80 controls the circulation of the inert gas in the circulation path 50 by controlling the first switching valve 62 and the second switching valve 64.

  The control unit 80 includes a determination unit 80a that determines that the inside of the chamber 20a is filled with an inert gas after the modeling apparatus 1 is activated. Immediately after the modeling apparatus 1 is activated (preparation stage of modeling), since the oxygen concentration and the water vapor concentration in the chamber 20a are high, the adsorption amount of the adsorption device 70 may reach the upper limit. Therefore, the determination unit 80a determines whether or not the chamber 20a is filled with an inert gas depending on whether or not the oxygen concentration in the chamber 20a is equal to or lower than a predetermined value. That is, as shown in FIG. 3A, the determination unit 80a determines that the inside of the chamber 20a is filled with an inert gas when the predetermined value is equal to or less than the third threshold value. The third threshold is 100 ppm, for example.

Here, the control based on the oxygen concentration by the control unit 80 will be described with reference to FIG.
As shown in FIG. 3A, the determination unit 80a sets a first threshold value, a second threshold value, and a third threshold value for the oxygen concentration. When the oxygen concentration is equal to or higher than the first threshold value, it is unsuitable to form the three-dimensional structure O because the oxygen concentration in the chamber 20a is too high. As shown in FIGS. 3B, 3 </ b> C, and 3 </ b> D, when the oxygen concentration is equal to or higher than the first threshold, the control unit 80 closes the first switching valve 62 so that the inert gas does not pass through the first branch path 53. The second switching valve 64 is opened, and the inert gas passes only through the second branch path 54. At this time, the control unit 80 closes the first on-off valve 73 and the second on-off valve 74 of the adsorption device 70 to suppress the ingress of the inert gas having a high oxygen concentration into the adsorption device 70. The first threshold value is, for example, 2,000 ppm, and the second threshold value is, for example, 1,000 ppm.

  As shown in FIG. 3 (a), when the oxygen concentration is equal to or higher than the second threshold value, the oxygen concentration in the chamber 20a is relatively high. Therefore, when the inert gas is passed through the adsorption device 70, the adsorption amount of the adsorption device 70 reaches the upper limit. This is a state that is likely to be reached (breakthrough). As shown in FIGS. 3B, 3 </ b> C, and 3 </ b> D, when the oxygen concentration is equal to or higher than the second threshold, the control unit 80 controls the first switching valve 62 in the same manner as when the oxygen concentration is equal to or higher than the first threshold. Close and open the second switching valve 64. On the other hand, if the oxygen concentration is less than the second threshold value, the control unit 80 opens the first switching valve 62 so that the inert gas passes through the first branch path 53, closes the second switching valve 64, and enters the second branch. The inert gas does not pass through the path 54. At this time, the control unit 80 opens the first on-off valve 73 and the second on-off valve 74 of the adsorption device 70 to allow the inert gas to pass through the adsorption device 70 and reduce oxygen and water vapor.

  When the inert gas is allowed to pass through the adsorption device 70 when the oxygen concentration is less than the second threshold value, not only the inert gas is passed through the first branch 53 but also the inert gas is passed through the second branch 54. Also good. That is, when the supply amount of the inert gas into the chamber 20a increases, the adsorption capacity of the adsorption device 70 may reach a limit before releasing oxygen or water vapor. On the other hand, if the supply amount of the gas discharged into the chamber 20a is limited so that the adsorption capacity does not reach the limit, the amount of gas necessary for fume removal cannot be discharged into the chamber 20a. Therefore, when the flow rate of the inert gas that passes through the first branch 53 is insufficient with respect to the flow rate of the inert gas that needs to be supplied into the chamber 20a, the inert gas passes through the second branch 54. Thus, the flow rate of the inert gas that needs to be discharged into the chamber 20a is satisfied. The control unit 80 holds the flow rate of the inert gas that needs to be supplied into the chamber 20a, and measures the flow rate of the inert gas discharged into the chamber 20a by the third flow meter 66. And the control part 80 controls the 2nd switching valve 64 so that the flow volume of the inert gas which is insufficient may be adjusted, and the flow volume of the inert gas which passes the 2nd branch path 54 is adjusted.

  As shown in FIG. 3A, when the oxygen concentration is equal to or lower than the third threshold, the adsorption amount of the adsorption device 70 does not reach the upper limit even if it passes through the adsorption device 70 as it is because the oxygen concentration in the chamber 20a is low. In addition to the state, the modeling start condition is satisfied. As shown in FIGS. 3B, 3 </ b> C, and 3 </ b> D, when the oxygen concentration is equal to or lower than the third threshold, the control unit 80 controls the first switching valve 62 in the same manner as when the oxygen concentration is lower than the second threshold. The state is opened so that the inert gas passes through the first branch 53, and the second switching valve 64 is closed so that the inert gas does not pass through the second branch 54. At this time, the control unit 80 opens the first on-off valve 73 and the second on-off valve 74 of the adsorption device 70 to allow the inert gas to pass through the adsorption device 70 and reduce oxygen and water vapor.

  When the modeling of the three-dimensional structure O is completed, the control unit 80 closes the inlet 70a and the outlet 70b of the adsorption device 70 by closing the first on-off valve 73 and the second on-off valve 74, so Prevent active gas from entering. At this time, the control unit 80 closes the first switching valve 62 so that the inert gas does not pass through the first branch path 53.

  Next, with reference to FIGS. 1-8, operation | movement of the modeling apparatus 1 comprised as mentioned above is demonstrated. As shown in FIG. 6, before the modeling apparatus 1 is started, the first switching valve 62 is closed, the second switching valve 64 is opened, and the first opening / closing valve 73 and the second opening / closing valve 74 are opened. Closed state.

  First, as shown in FIG. 4, when the modeling apparatus 1 is activated, the control unit 80 supplies and circulates the inert gas so as to fill the chamber 20 a with the inert gas. That is, the control unit 80 drives the blower 59 to circulate the inert gas while supplying the inert gas from the supply unit 75 to the circulation path 50.

  The control unit 80 causes the inert gas to flow only in the second branch 54 that is the second circulation path (step S11). Since the oxygen concentration and the water vapor concentration in the chamber are high immediately after the modeling apparatus 1 is activated, the second branch path 54 in which the adsorption device 70 is not provided so that the adsorption amount of the adsorption device 70 does not reach the upper limit. Only let gas pass through. That is, as shown in FIG. 6, the control unit 80 is configured such that the first switching valve 62, which is in a state before activation, is closed, the second switching valve 64 is opened, and the first on-off valve 73 and the second on-off valve 74 remains closed. At this time, the flow rate Q3 measured by the third flow meter 66 coincides with the flow rate Q2 measured by the second flow meter 65 (Q3 = Q2). As shown in FIG. 3, the oxygen concentration that is equal to or higher than the first threshold value decreases as the inert gas is supplied.

  Subsequently, as shown in FIG. 4, the controller 80 determines whether or not the oxygen concentration in the chamber 20a is less than the second threshold value (step S12). That is, when the determination unit 80a compares the oxygen concentration measured by the oxygen sensor 81 with the second threshold value and determines that the oxygen concentration in the chamber 20a is equal to or higher than the second threshold value (step S12: NO) The process proceeds to step S11.

  On the other hand, when the determination unit 80a determines that the oxygen concentration in the chamber 20a is less than the second threshold value (step S12: YES), the determination unit 80a supplies an inert gas to the first branch path 53 that is the first circulation path. (Step S13). As shown at timing t1 in FIG. 3, the oxygen concentration that is equal to or higher than the first threshold value is decreased by the supply of the inert gas and becomes less than the second threshold value. That is, since the oxygen concentration in the chamber 20a is relatively low and the adsorption amount of the adsorption device 70 does not reach the upper limit, the adsorption device 70 is provided to adsorb oxygen and water vapor contained in the gas. Gas is passed through the first branch 53. That is, as shown in FIG. 8, the control unit 80 opens the first switching valve 62, closes the second switching valve 64, opens the first on-off valve 73 and the second on-off valve 74, and drives the blower 61. Thus, the gas is allowed to pass through only the first branch 53. As shown in FIG. 7, the control unit 80, when only the flow rate Q1 passing through the first branch path 53 is insufficient for the gas flow rate QC that needs to be discharged into the chamber 20a (Q1 <QC ), The second switching valve 64 is also opened, and the gas is passed through the second branch 54. By doing so, the flow rate QC of the gas that needs to be discharged into the chamber 20a is equal to or less than the sum (Q3 = Q1 + Q2) of the flow rate Q1 of the first branch 53 and the flow rate Q2 of the second branch 54 ( Q3 = Q1 + Q2 ≧ QC). As indicated by a broken line in FIG. 3C, the control unit 80 opens the second switching valve 64 in accordance with a necessary flow rate.

  Subsequently, as shown in FIG. 4, the control unit 80 determines whether or not the oxygen concentration in the chamber 20a is less than a third threshold (step S14). That is, when the determination unit 80a compares the oxygen concentration measured by the oxygen sensor 81 with the third threshold value and determines that the oxygen concentration in the chamber 20a is equal to or higher than the third threshold value (step S14: NO) The process continues until the oxygen concentration in the chamber 20a becomes less than the third threshold value.

  On the other hand, when the determination unit 80a determines that the oxygen concentration in the chamber 20a is less than the third threshold (step S14: YES), the determination unit 80a determines that the start condition for modeling the three-dimensional structure O is established ( Step S15). As shown at timing t2 in FIG. 3, the oxygen concentration is further lowered by the supply of the inert gas and becomes less than the third threshold value. That is, the oxygen concentration in the chamber 20a is sufficiently low, and even if the three-dimensional structure O is formed, the oxidation and water vapor content can be suppressed within the specified value. Allow and exit.

  Next, as illustrated in FIG. 4, when the modeling apparatus 1 starts modeling, the control unit 80 is generated along with the modeling of the three-dimensional modeled object O by continuing the supply and circulation of the inert gas. Remove fumes and the like. That is, the control unit 80 drives the blower 59 to circulate the inert gas while supplying the inert gas from the supply unit 75 to the circulation path 50.

  The modeling apparatus 1 includes a process of laminating the powder layer 25 made of the powder material M, and a process of partially solidifying the powder layer 25 by irradiating a laser on the laser irradiation surface 25a of the powder layer 25. The three-dimensional structure O is manufactured by repeating the above.

  When irradiating the powder layer 25 with the laser, the fume removal flow F along the laser irradiation surface 25a is formed by the inert gas whose oxygen concentration and water vapor concentration are reduced by the adsorption device 70.

  When the laser is irradiated onto the laser irradiation surface 25a of the powder layer 25, fumes are generated from the laser irradiation portion and spatter is scattered. Since the fumes generated from the laser irradiation site are immediately flown by the fume removal flow F, they rise and are sucked from the suction port 41 without blocking the laser path. Moreover, since the spatter scattered from the laser irradiation site is scattered in the fume removal flow F in which the oxygen concentration and the water vapor concentration are reduced, the oxidation during the scattering can be suppressed, and the spatter is oxidized and falls. Can be suppressed. Further, since the fume removal flow F is formed by the inert gas whose oxygen concentration and water vapor concentration are reduced by the adsorption device 70, the oxidation of the powder material M of the powder layer 25 by the fume removal flow F is suppressed. In this way, the powdered material M is oxidized, that is, the oxidation of the three-dimensional structure O is suppressed by forming the three-dimensional structure O while flowing the inert gas with reduced oxygen concentration and water vapor concentration into the chamber 20a. can do.

  During the modeling of the three-dimensional structure O, the control unit 80 causes a gas to flow through the first branch path 53 that is the first circulation path (step S21). Subsequently, the control unit 80 determines whether or not the oxygen concentration in the chamber 20a is equal to or higher than the first threshold value (step S22). That is, when the determination unit 80a compares the oxygen concentration measured by the oxygen sensor 81 with the first threshold value and determines that the oxygen concentration in the chamber 20a is equal to or higher than the first threshold value (step S22: NO) Since the oxygen concentration in the chamber 20a is too high, the modeling of the three-dimensional structure O is stopped (step S27). As shown at timing t5 in FIG. 3, when the supply of the inert gas cannot be performed or oxygen flows into the chamber 20a, the first threshold value is reached.

  On the other hand, when the determination unit 80a determines that the oxygen concentration in the chamber 20a is less than the first threshold value (step S22: YES), the determination unit 80a determines whether the oxygen concentration in the chamber 20a is equal to or higher than the second threshold value. Determination is made (step S23). That is, the determination unit 80a compares the oxygen concentration measured by the oxygen sensor 81 with the second threshold value and determines that the oxygen concentration in the chamber 20a is less than the second threshold value (step S23: NO). The process proceeds to step S21.

  On the other hand, when the determination unit 80a compares the oxygen concentration measured by the oxygen sensor 81 with the second threshold value and determines that the oxygen concentration in the chamber 20a is equal to or higher than the second threshold value (step S23: YES). Then, the inert gas is allowed to flow only through the second branch 54 which is the second circulation path (step S24). As shown at timing t4 in FIG. 3, the inert gas cannot be supplied, or oxygen flows into the chamber 20a, so that the oxygen concentration rises and becomes the second threshold value or more.

  Subsequently, the control unit 80 determines whether or not the modeling of the three-dimensional structure O is completed (step S25). That is, if the modeling of the three-dimensional structure O has not been completed (step S25: NO), the control unit 80 proceeds to step S21. That is, since the control unit 80 continues to supply and circulate the inert gas during the modeling of the three-dimensional structure O, the above process is repeated.

  On the other hand, if the modeling of the three-dimensional structure O has been completed (step S25: YES), the control unit 80 closes the first branch path 53 that is the first circulation path (step S26), and ends the process. To do. That is, the control unit 80 closes the first switching valve 62 and closes the first on-off valve 73 and the second on-off valve 74 so that the gas does not enter the adsorption device 70 and seals the adsorption device 70. Further, the control unit 80 stops driving the blower 59 and the blower 61.

As described above, according to this embodiment, the following effects can be obtained.
(1) Since the gas does not pass through the adsorption device 70 until the interior of the chamber 20a is filled with gas after the modeling device 1 is activated (modeling preparation stage), the adsorption amount of oxygen and water vapor in the adsorption device 70 is the upper limit. Can be effectively suppressed.

(2) Since the determination is made directly based on the oxygen concentration in the chamber 20a, it is possible to suppress the oxygen adsorption amount of the adsorption device 70 from reaching the upper limit.
(3) Since the gas does not pass through the adsorption device 70 after the modeling of the three-dimensional modeled object, the performance deterioration of the adsorption device 70 due to the passage of the gas can be suppressed.

  (4) Since the inflow port 70a and the outflow port 70b of the adsorption device 70 are closed after the modeling of the three-dimensional structure O is completed, the performance degradation of the adsorption device 70 can be suppressed by using a sealed space.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, the inlet 70a and the outlet 70b of the adsorption device 70 are closed after the formation of the three-dimensional structure O, but the inlet 70a and the outlet 70b of the adsorption device 70 are not closed. Also good.

Further, the configuration of the first on-off valve 73 and the second on-off valve 74 may be omitted.
In the above embodiment, the configuration of the blower 61 provided in the first branch path 53 may be omitted.

  In the above embodiment, when the modeling of the three-dimensional structure O is completed, the gas is changed so as to pass only through the second branch path 54. However, the first operation when the modeling of the three-dimensional structure O is completed is performed. The passage state between the branch path 53 and the second branch path 54 may be left as it is.

  In the above embodiment, the determination unit 80a determines based on the oxygen concentration in the chamber 20a, and the control unit 80 switches between the first branch path 53 and the second branch path 54. However, the determination unit 80a may determine that the inside of the chamber 20a is filled with gas based on the fact that the integrated value of the gas flow rate measured by the flow meter has reached a predetermined amount. If the flow rate is constant, the time during which the chamber 20a is filled with gas can be estimated by dividing the capacity of the chamber 20a by the gas flow rate. .

  In the above embodiment, the determination unit 80a determines based on the oxygen concentration in the chamber 20a, and the control unit 80 switches between the first branch path 53 and the second branch path 54. However, the determination unit 80a determines that the inside of the chamber 20a is filled with gas based on the fact that the integrated value of the gas flow rate measured by the flow meter reaches a predetermined amount calculated in advance based on the capacity in the chamber 20a. May be. According to this, it is possible to make an appropriate determination according to the gas flow rate without using a plurality of expensive oxygen sensors. In addition, if the flow rate is constant, it is possible to estimate the time during which the chamber 20a is filled with gas by dividing a predetermined amount calculated in advance based on the volume in the chamber 20a by the gas flow rate. The determination unit 80a may determine that the inside of the chamber 20a is filled with the gas based on the passage of the time from the start of the gas flow using a timer built in the gas 80. According to this, determination can be performed without using a special sensor for determination.

In the above embodiment, the adsorption device 70 may adsorb hydrogen contained in the gas and remove the hydrogen from the gas.
In the above embodiment, the flow rate of the gas that needs to be discharged into the chamber 20a may be smaller than the maximum flow rate of the second branch 54.

  In the above embodiment, the adsorption device 70 is an apparatus that adsorbs both oxygen and water vapor, but the adsorption device 70 may be an apparatus that adsorbs only one of oxygen and water vapor.

  In the above embodiment, Ar gas is used as the inert gas filled in the chamber 20a. However, the gas is not limited to Ar gas, and He gas, Ne gas, N gas, or the like may be used. Further, CO gas may be used as the gas filled in the chamber 20a. Further, if the possibility of hydrogen embrittlement is low, H gas may be used as the gas filled in the chamber.

  In the above embodiment, the first branch path 53 and the second branch path 54 are provided in the second path 52 of the circulation path 50, but both the first circulation path and the second circulation path are circulated. A plurality of second paths 52 of the path 50 may be provided. For example, as shown in FIG. 9, a first branch path 53 and a third branch path 55 corresponding to the first circulation path and a second branch path 54 corresponding to the second circulation path may be provided. Further, as shown in FIG. 10, a first branch path 53 corresponding to the first circulation path, and a second branch path 54 and a third branch path 55 corresponding to the second circulation path may be provided. Further, as shown in FIG. 11, a first branch path 53 corresponding to the first circulation path, a second branch path 54, a third branch path 55, and a fourth branch path 56 corresponding to the second circulation path, May be provided. Further, as shown in FIG. 12, the first branch path 53 and the third branch path 55 corresponding to the first circulation path, and the second branch path 54 and the fourth branch path 56 corresponding to the second circulation path, May be provided.

  DESCRIPTION OF SYMBOLS 1 ... Modeling apparatus, 10 ... Laser irradiation part, 20 ... Modeling part, 20a ... Chamber, 20b ... Side wall, 21 ... Container, 22 ... Modeling table, 23 ... Modeling plate, 24 ... Recoater, 25 ... Powder layer, 25a ... Laser irradiation surface, 26 ... fume removal flow forming part, 30 ... discharge part, 31 ... discharge port, 40 ... suction part, 41 ... suction port, 50 ... circulation path, 51 ... first path, 52 ... second path, 53 ... 1st branch path, 54 ... 2nd branch path, 55 ... 3rd branch path, 56 ... 4th branch path, 58 ... Fine powder removal filter, 59 ... Blower, 61 ... Blower, 62 ... 1st switching valve, 63 ... 1st flow meter, 64 ... 2nd switching valve, 65 ... 2nd flow meter, 66 ... 3rd flow meter, 67 ... 4th flow meter, 68 ... 5th flow meter, 70 ... Adsorption device, 70a ... Inlet, 70b ... Outlet, 71 ... Oxygen adsorption part, 72 ... Water vapor adsorption part, 73 ... No. On-off valve, 74 ... second on-off valve, 75 ... supply unit, 76 ... tank, 80 ... control unit, 80a ... determination unit, 81 ... oxygen sensor, 82 ... water vapor sensor, 83 ... first flow meter, 84 ... second Flow meter, 85 ... third flow meter, F ... fume removal flow, M ... powder material, O ... three-dimensional structure.

Claims (3)

A modeling apparatus for manufacturing a three-dimensional structure by repeating a process of partially solidifying the powder layer by irradiating a laser on a powder layer made of a powder material,
A discharge port for discharging a gas for removing fumes into the chamber;
A suction port for sucking the gas in the chamber;
An adsorption device for adsorbing at least one of oxygen and water vapor contained in the gas;
A circulation path that connects the discharge port and the suction port to circulate the gas from the suction port to the discharge port, the first circulation path provided with the adsorption device, and the adsorption device provided A plurality of circulation paths including a second circulation path that is not
A flow control unit that adjusts the amount of the gas passing through the first circulation path and the amount of the gas passing through the second circulation path. The modeling apparatus according to claim 1, wherein a maximum flow rate of the second circulation path is equal to or greater than a flow rate of the gas that needs to be discharged into the chamber. The modeling apparatus according to claim 1, wherein a filter that removes fine powder contained in the gas when the gas passes is provided upstream of the adsorption device in the first circulation path.