JP2018047597A - Method of manufacturing three-dimensional molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a three-dimensional molded article suppressing solidification of a material powder at an unintentional place in a drying process by heating and drying, and a three-dimensional molding apparatus.SOLUTION: The method of manufacturing a three-dimensional molded article includes: a preparing process; a molding process; and a heating process. In the preparing process, a molding tank 20 provided inside with a molding table 30 having permeability is prepared. In the molding process, a hardening liquid is discharged to a predetermined place on a material powder 300 laid on the molding table 30 to form a layer of material powder layers obtained by bonding the material powder 300 at the predetermined place, and the material powder layers are lapped over upward one by one to mold a three-dimensional molded article 320 in the material powder 300 in the molding tank 20. In the heating process, the three-dimensional molded article 320 in the molding tank 20 is heated after the molding process.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a three-dimensional structure.

  2. Description of the Related Art Conventionally, a three-dimensional modeling apparatus that forms a three-dimensional model by discharging an adhesive substance onto a powder material and curing the powder material is known. As shown in Patent Document 1, a three-dimensional modeling apparatus of a type that cures a powder material includes, for example, a modeling chamber that stores a powder material, a material storage chamber that stores a powder material supplied to the modeling chamber, A material supply unit for supplying a powder material from the material storage chamber to the modeling chamber. A printing head that discharges an adhesive substance is disposed above the modeling chamber. The printing head discharges an adhesive substance to a portion corresponding to the cross-sectional shape of the three-dimensional structure in the powder material accommodated in the modeling chamber. The portion of the powder material where the adhesive substance is discharged is cured, and a powder cured layer corresponding to the cross-sectional shape is formed.

JP 2006-137173 A

  By the way, in the manufacturing method of a powder hardening type three-dimensional structure, when the curing time is long, the three-dimensional structure may be heated and dried after the formation. In the manufacturing method of the powder-curing type three-dimensional structure, the three-dimensional structure is formed in the modeling tank, so that the heat drying is performed for each modeling tank. However, when heated and dried, the material powder in a place not intended for curing in the modeling tank may solidify.

  The present invention has been made in view of such a problem, and the object of the present invention is to provide a method for manufacturing a three-dimensional structure that suppresses hardening of a material powder at an unintended place in heat drying, and a material powder at an unintended place. It is to propose a three-dimensional modeling apparatus having a mechanism for suppressing curing.

  The manufacturing method of the three-dimensional structure proposed here has a preparation process, a modeling process, and a heating process. In the preparation step, a modeling tank in which a modeling table having air permeability is arranged is prepared. In the modeling process, the material powder is spread on a modeling table in a predetermined thickness, and the material at the predetermined position is discharged by discharging a curable liquid to a predetermined position on the spread material powder. One material powder layer to which the powder is bonded is formed. Then, a predetermined three-dimensional structure is formed in the material powder in the modeling tank by stacking the material powder layers one by one in the modeling tank. The heating process is performed after the modeling process, and heats the three-dimensional modeled object in the modeling tank.

  By making the modeling table have air permeability, solidification of the material powder in an unintended place in the modeling tank can be suppressed in heat drying.

It is sectional drawing which looked at the three-dimensional modeling apparatus in one Embodiment from the front. It is the top view which looked at the three-dimensional modeling apparatus of FIG. 1 from upper direction. It is sectional drawing which looked at the heating furnace in one Embodiment from the front. It is sectional drawing which looked at the heating furnace provided with the heater from the front. It is sectional drawing which looked at one Embodiment of the three-dimensional modeling apparatus provided with the mechanism which suppresses solidification which material powder does not intend from the front. It is sectional drawing which looked at the three-dimensional modeling apparatus provided with the heater in the heating mechanism from the front.

  Hereinafter, embodiments of the present invention will be described. The embodiments described herein are, of course, not intended to limit the present invention. Further, members / parts having the same action are denoted by the same reference numerals, and redundant description is omitted or simplified.

  As described above, in the heat drying of the three-dimensional structure, a problem that an unintended place of the material powder in the modeling tank is solidified sometimes occurs (hereinafter, the material in the unintended place in the modeling tank). The solidification of the powder is simply called unintentional solidification). The inventor of the present application has found that this unintentional solidification occurs because heat and vapor of the curable liquid generated by heating are trapped in the material powder in the modeling tank 20. Therefore, unintentional solidification can be suppressed by relaxing the heat and steam in the modeling tank. The inventor of the present application has found that in order to alleviate the heat and steam in the modeling tank, the material tank may be ventilated. And it discovered that the ventilation | gas_flowing in a modeling tank was improved by making a modeling table what has air permeability, and the solidification which is not intended can be suppressed.

  The manufacturing method of the three-dimensional structure disclosed here has a preparation process, a modeling process, and a heating process. In the preparation step, a modeling tank in which a modeling table having air permeability is arranged is prepared. In the modeling process, the material powder is spread on a modeling table in a predetermined thickness, and the material at the predetermined position is discharged by discharging a curable liquid to a predetermined position on the spread material powder. One material powder layer to which the powder is bonded is formed. Then, a predetermined three-dimensional structure is formed in the material powder in the modeling tank by stacking the material powder layers one by one in the modeling tank. The heating process is performed after the modeling process, and heats the three-dimensional modeled object in the modeling tank.

  According to one preferable embodiment of the present manufacturing method, the preparation process / modeling process and the heating process are performed in separate apparatuses. The preparation process / modeling process is performed by a three-dimensional modeling apparatus. After completion of the modeling process, the modeling tank containing the three-dimensional modeled object is removed from the three-dimensional modeling apparatus and put into a heating furnace. And a heating process is implemented in a heating furnace.

  First, an embodiment of a three-dimensional modeling apparatus in which a preparation process and a modeling process are performed will be described. FIG. 1 is a cross-sectional view of a three-dimensional modeling apparatus 10 according to an embodiment as viewed from the front. The left side of FIG. 1 is the left side L of the three-dimensional modeling apparatus 10. Similarly, the right side of FIG. 1 is the right side R of the 3D modeling apparatus 10, the upper side of FIG. 1 is the upper side U of the apparatus, and the lower side of FIG. FIG. 2 is a plan view of the three-dimensional modeling apparatus 10 of FIG. 1 as viewed from above. 1 is a cross-sectional view taken along the line II in FIG. Therefore, the left side of FIG. 2 is the left side L of the 3D modeling apparatus 10, the right side of FIG. 2 is the right side R of the 3D modeling apparatus 10, the lower side of FIG. 2 is the front F of the apparatus, and the upper side of FIG. It is the rear Rr of the original modeling apparatus. Henceforth, when describing a direction in description of the three-dimensional modeling apparatus 10, the above-mentioned direction shall be meant. However, these are only directions for convenience of explanation, and do not limit the installation mode of the three-dimensional modeling apparatus 10.

  As shown in FIGS. 1 and 2, according to the present embodiment, the three-dimensional modeling apparatus 10 includes a housing 12, a modeling tank 20, a modeling table 30, a first lifting mechanism 40, and a material tank 42. The second elevating mechanism 44, the roller 46, the discharge head 48, the tank 50, and the moving mechanism 52 are provided.

  The modeling table 30 is arranged inside the modeling tank 20. In the modeling tank 20, the modeling table 30 is supported by the 1st raising / lowering mechanism 40 from the downward direction, and can slide up and down. The first lifting mechanism 40 can move the modeling table 30 up and down in the modeling tank 20. The 1st raising / lowering mechanism 40 is provided with the cylinder which raises / lowers, for example. This cylinder is an electric cylinder driven by a servo motor and a ball screw. The modeling table 30 is merely fixed on the first elevating mechanism 40 and is not fixed. The modeling tank 20 is placed on the housing 12 as shown in FIG. The modeling tank 20 is preferably only placed on the housing 12, but if it is unstable, it is preferably fixed by a fixing method that can be easily removed. The modeling tank 20 has a step 20a on which the modeling table 30 is caught, and the modeling table 30 does not fall even if the first lifting mechanism 40 is not supported. By having such a structure, if the cylinder of the 1st raising / lowering mechanism 40 is lowered | separated until it leaves | separates from the modeling table 30, the modeling tank 20 and the modeling table 30 can be easily removed from the three-dimensional modeling apparatus 10. FIG. All or most of the modeling table 30 is composed of a porous plate 32 having air permeability. In the modeling table 30, it is desirable that a portion where the three-dimensional model 320 can be modeled is composed of a porous plate 32. The material of the porous plate 32 is, for example, a plastic sintered body such as a sintered body of polypropylene particles, or a ceramic sintered body. A material powder 300 is spread on the modeling table 30. Since the three-dimensional structure 320 is formed by stacking the layers of the material powder 300 laid on the modeling table 30 to which the material powder 300 at a predetermined position is bonded one by one upward, The three-dimensional structure 320 is placed so that the part of the three-dimensional structure 320 that has been shaped so far is embedded in the material powder 300.

  In this embodiment, the material tank 42 is next to the modeling tank 20 and stores the material powder 300. The material tank 42 is one of mechanisms for supplying the material powder 300 onto the modeling table 30. The bottom part 42 a of the material tank 42 can slide up and down in the material tank 42. A second elevating mechanism 44 is connected to the lower surface of the bottom portion 42a. The second elevating mechanism 44 also has a cylinder that elevates and lowers similarly to the first elevating mechanism 40, and the second elevating mechanism 44 moves the bottom 42 a up and down in the material tank 42 by this cylinder. The material powder 300 stored in the material tank 42 is, for example, a powder of gypsum, ceramics, metal, plastic, or the like.

  The roller 46 is a mechanism that spreads the material powder 300 on the modeling table 30. The roller 46 is horizontally moved in the left-right direction by a drive unit (not shown), and the material powder 300 is spread on the modeling table 30 with a predetermined thickness. Therefore, the height of the upper surface of the material powder 300 to be spread is the height of the lower portion of the roller 46. The roller 46 is designed such that the length in the front-rear direction is longer than the width in the front-rear direction of the modeling tank 20 and the material tank 42 so that the material powder 300 is spread over the entire surface of the modeling table 30.

  The discharge head 48 is a mechanism for discharging a liquid such as a curable liquid onto the material powder 300. The ejection heads 48 are held in rows in the left-right direction by the holding portion 52a. The discharge head 48 is held with the discharge surface facing downward D so that the liquid can be discharged toward the material powder 300 on the modeling table 30. As shown in FIG. 1, each ejection head 48 is connected to one tank 50. And the discharge liquid accommodated in the tank 50 connected to each is discharged. At least one of the discharge liquids is a curable liquid that cures the material powder 300, and the discharge liquids other than the curable liquid are, for example, color liquids such as cyan, magenta, and yellow. Of course, this is only an example, and a necessary liquid may be prepared for implementation. For example, a piezo drive system is employed as the drive system of the ejection head 48. A piezo drive type discharge head includes a pressure chamber filled with a liquid to be discharged. A fine nozzle hole is formed in the pressure chamber. A piezoelectric element (piezo element) is in contact with the outer wall of the pressure chamber. At this time, when a voltage is applied to the piezo element, the variation of the piezo element due to the voltage application is transmitted to the pressure chamber. As a result, the volume of the pressure chamber is reduced, and the reduced volume is ejected as droplets.

  The moving mechanism 52 is a mechanism that holds the discharge head 48 and moves the modeling tank 20. The moving mechanism 52 includes a holding unit 52 a that holds the discharge head 48, and the discharge head 48 that is held by the holding unit 52 a above the upper surface of the material powder 300 that is spread on the upper surface of the material powder 300. Move at a distance. The predetermined distance is, for example, about 2 mm. According to the embodiment shown in FIGS. 1 and 2, the moving mechanism 52 scans the ejection head 48 in the main scanning direction Y and the sub-scanning direction X. The main scanning direction Y is a direction in which the ejection head 48 is scanned while performing ejection (that is, while performing modeling). The sub-scanning direction X is a direction that intersects the main scanning direction Y, and is usually orthogonal to the main scanning direction Y. Although this intersection is not limited to orthogonal, in the present embodiment, the main scanning direction Y is the left-right direction, and the sub-scanning direction X is the front-rear direction. The moving mechanism 52 includes a main scanning unit 52y that moves the ejection head 48 in the main scanning direction Y and a sub-scanning unit 52x that moves the ejection head 48 in the sub-scanning direction X. The main scanning unit 52y is connected to the holding unit 52a and moves the holding unit 52a in the Y direction along the main scanning unit guide rail 52yg. The sub-scanning unit 52x is connected to the main scanning unit 52y and moves the main scanning unit 52y in the X direction along the sub-scanning unit guide rail 52xg. In the embodiment shown here, the modeling tank 20 is stationary during modeling, and the discharge head 48 is moved by the moving mechanism 52. However, this movement may be a relative one. However, it may be moved in either the main scanning direction Y, the sub-scanning direction X, or both.

  The material powder 300 is, for example, a mixed powder of alumina and PVA (polyvinyl alcohol). PVA is a water-soluble resin and is a bonding agent in modeling using such material powder. Since PVA is water-soluble, water is used as the curable liquid discharged from the discharge head 48. A small amount of a surfactant for adjusting the surface tension may be added to the water.

  Next, the preparation process and the modeling process will be described. A preparation process is a process of preparing the modeling tank 20 which has arrange | positioned the modeling table 30 which has air permeability inside. In the three-dimensional modeling apparatus 10 according to the present embodiment, the modeling tank 20 and the modeling table 30 are configured to be easily detachable from the three-dimensional modeling apparatus 10, and the heating process is performed after being removed from the three-dimensional modeling apparatus 10. The Therefore, the removed modeling tank 20 and the modeling table 30 are mounted on the modeling tank 10 again in the preparation process. In the preparation process, it is particularly desirable to clean the modeling table 30 and ensure the air permeability of the porous plate 32 that forms the main part of the modeling table 30. The modeling table 30 is placed in the modeling tank 20 so as to be caught by the step 20 a in the modeling tank 20, and the modeling tank 20 is set at a predetermined position on the housing 12. The modeling table 30 is moved to the initial position by the first lifting mechanism 40 in the modeling tank 20. The initial position is the highest position in the modeling tank 20. As the process proceeds from the next step onward, the modeling table 30 gradually moves in the modeling tank 20 to a lower position. In addition, the implementation content of said preparation process is the implementation content of the preparation process in the case of this embodiment, Comprising: A preparation process is not limited to the above implementation content. For example, in the embodiment in which the three-dimensional modeling apparatus 10 performs the heating process, the modeling tank 20 is not removed, so that the modeling tank 20 is not naturally remounted, and only the modeling table 30 is cleaned or replaced as appropriate. Is done.

  Following the preparation process, a modeling process is performed. In the three-dimensional modeling apparatus 10, the three-dimensional model 320 is modeled by successively laminating a hardened layer having a predetermined thickness of, for example, about 0.1 mm. The term “cured layer” as used herein refers to the material powder 300 bonded in a predetermined shape with a curable liquid in one material powder layer. Therefore, the shape of the hardened layer at a certain height in the vertical direction is the cross-sectional shape of the three-dimensional structure 320 at that height. The material powder 300 constituting the material powder layer is supplied from the material tank 42. In the supply process of the material powder 300, first, the modeling table 30 is moved downward D in the modeling tank 20 by the first lifting mechanism 40. The amount of movement of the modeling table 30 at this time is the thickness of one cured layer. Next, the bottom part 42 a of the material tank 42 is moved upward U in the material tank 42 by the second lifting mechanism 44. Therefore, a part of the material powder 300 in the material tank 42 is raised and stacked above the upper end of the material tank 42. The material powder 300 raised and stacked is moved in the direction of the modeling tank 20 by the horizontal movement of the roller 46 in the R direction and leveled on the modeling table 30. By this series of operations, the material powder 300 is spread on the modeling table 30 with a predetermined thickness of, for example, about 0.1 mm. Excess material powder 300 is removed by the roller 46 as it is, and is recovered in a material recovery tank (not shown). Thus, a material powder layer having a predetermined height and thickness is formed on the modeling table 30. However, the method for forming the material powder layer is an example, and the method for forming the material powder layer is not limited to the method described here.

  Subsequently, modeling and coloring are performed by the ejection head 48 ejecting a liquid other than the curing liquid onto the material powder 300 leveled on the modeling table. The discharge head 48 is scanned by the main scanning unit 52y in the main scanning direction Y1 while being held by the holding unit 52a. Here, the Y1 direction in the main scanning direction Y is the forward direction during modeling. During scanning in the Y1 direction, the discharge head 48 discharges the liquid stored in the tank 50 to which the discharge head 48 is connected, toward the material powder 300. When the discharge operation is completed at one position on the X axis in this way, the discharge head 48 is returned to the Y2 direction by the main scanning unit 52y. Further, the ejection head 48 is moved in the sub-scanning direction X1 by the sub-scanning unit 52x. Of the sub-scanning direction X, the X1 direction is the forward direction during modeling. Even at the position after this movement, the ejection head 48 performs modeling and coloring work while being scanned in the main scanning direction Y1. In this way, the ejection head 48 is scanned over the entire modeling area, and modeling for one layer of the material powder layer is completed. The three-dimensional modeling apparatus 10 models the three-dimensional shape of the three-dimensional structure 320 by repeating this one-layer modeling process and stacking the layers one layer at a time.

  Then, a heating process is demonstrated. Upon completion of the modeling process, the process of using the three-dimensional modeling apparatus 10 is completed, and the process proceeds to a heating process performed in a heating furnace. Between the modeling process and the heating process, the operator removes the modeling tank 20 from the three-dimensional modeling apparatus 10 and puts it into the heating furnace. For example, when the mixed powder of alumina powder and PVA is cured with water as in this embodiment, it takes 24 hours or more to cure if it is naturally dried. Since this takes too much time, it is common to perform heat drying in a heating furnace or the like. First, an embodiment of a heating furnace will be described. FIG. 3 is a cross-sectional view of the heating furnace 60 as viewed from the front according to one embodiment. The left side of FIG. 3 is the left side L of the heating furnace 60. Similarly, the right side of FIG. 3 is the right side R of the heating furnace 60, the upper side of FIG. 3 is the upper side U of the heating furnace 60, and the lower side of FIG. Hereinafter, when the direction is described in the description of the heating furnace 60, the above direction is meant. However, of course, these are only directions for convenience of explanation, and the installation mode of the heating furnace 60 is not limited.

  The heating furnace 60 includes a furnace body 62, a microwave irradiation mechanism 64 with a heating furnace, a blower 80 with a heating furnace, an exhaust mechanism 90 with a heating furnace, and a dehumidification mechanism 100 with a heating furnace. Further, in the heating furnace 60, a modeling tank 20 and a modeling table 30 which are removed from the three-dimensional modeling apparatus 10 after completion of the modeling process are put. The modeling table 30 is placed on the step 20 a in the modeling tank 20, and an undried three-dimensional model 320 is embedded in the material powder 300 and placed on the modeling table 30.

  The microwave irradiation mechanism 64 with a heating furnace is disposed on the right side surface of the furnace body 62. Microwaves are electromagnetic waves having a frequency of 2450 MHz in commercial use and having a wavelength suitable for dielectrically heating water. Microwaves can selectively and rapidly heat water. In this embodiment, since the curable liquid is water, the microwave heating method is suitable for drying the three-dimensional structure 320. Even in the case of this example, since the solvent of the curable liquid is generally water, the microwave heating method can be used in many cases. Microwave heating is advantageous in terms of drying time because it can rapidly heat water. The microwave irradiation mechanism 64 with a heating furnace is equipped with a magnetron and irradiates the modeling tank 20 with microwaves. The output of the microwave irradiation mechanism may be about 50 W or more, for example.

  The heating furnace-equipped blower 80 is connected to a blower opening 82 opened at the bottom of the furnace body 62. Since the modeling tank 20 is placed on the blower opening 82, the blower 80 with a heating furnace can send air into the modeling tank 20 through the porous plate 32 of the modeling table 30. The blower 80 with a heating furnace is, for example, an electric fan. The blower 80 with a heating furnace is controlled so as to send air into the modeling tank 20 through the blowing port 82 and the modeling table 30 at a predetermined air volume for a predetermined time during the heating process.

  The heating furnace-equipped exhaust mechanism 90 is installed on the ceiling of the furnace body 62 and exhausts the air inside the modeling tank 20. The heating furnace-equipped exhaust mechanism 90 is preferably installed so as to be opened in a space above the modeling tank 20 so that water vapor generated from the modeling tank 20 can be exhausted by heating. The heating furnace-equipped exhaust mechanism 90 is, for example, an exhaust pump, an exhaust fan, or the like, or a pipe connected to a building exhaust facility or the like.

  The dehumidifying mechanism 100 with a heating furnace includes a water absorbing material 102 that absorbs water vapor and a holding component 104 that holds the water absorbing material 102 and fixes it to the furnace body 62. The water absorbing substance 102 is, for example, silica gel, various water absorbing polymers, or sponge. It is desirable that the dehumidifying mechanism 100 with the heating furnace is also installed in the space above the modeling tank 20 so as to absorb the water vapor generated from the modeling tank 20 and dehumidify the inside of the furnace body 62. In the present embodiment, the dehumidifying mechanism 100 with the heating furnace is disposed, for example, on the entire ceiling of the furnace body 62. Since the water-absorbing substance 102 is a consumable item, it can be easily exchanged.

  The process of the heating process by the heating furnace 60 is as follows. The heating process is started after the modeling tank 20 is set at a predetermined position in the furnace body 62 by the operator. In the initial stage of the heating process, the output of the microwave irradiation mechanism 64 with a heating furnace is set to a low output. This is because, when heated at a high output in the initial stage of heating, there is a high risk of the shape of the three-dimensional structure 320 being destroyed by the generated water vapor. In order to prevent this deformation, at the beginning of heating, the output of the microwave irradiation mechanism 64 with a heating furnace is set low. The output at that time is, for example, about 30 W and is adjusted so that the temperature of the three-dimensional structure 320 is about 50 ° C. Furthermore, in order to secure the merit of microwave heating that drying time is early, the microwave irradiation mechanism output 64 is set so as to increase the output stepwise. This is, for example, a setting such that the output in the latter half of the heating process is about 50 W. At this time, the temperature of the three-dimensional structure 320 is adjusted to about 70 ° C. Alternatively, the heating power may be adjusted by intermittent irradiation instead of adjusting the output itself. Intermittent irradiation is a method of adjusting the average output by turning on microwave irradiation for a certain time and turning it off for a certain time.

  During heating, the blower 80 with a heating furnace sends wind into the modeling tank 20 through the modeling table 30 having air permeability. By this blowing process, the heat and water vapor that are confined in the modeling tank 20 and cause unintentional solidification of the material powder 300 are discharged out of the modeling tank 20. The air volume at this time is controlled to an air volume that does not cause the material powder 300 to fly up. Moreover, a ventilation process is implemented through the whole heating process.

  Similarly, the heating furnace-equipped exhaust mechanism 90 exhausts the air in the furnace body 62 during heating. This air is air containing water vapor generated by heating. Since microwaves selectively heat only water, the inside of the heating furnace remains close to normal temperature, and the generated water vapor tends to dew and form water droplets. The condensed water droplets can cause unintentional solidification of the material powder 300 again. Therefore, in the heating furnace 60 in the present embodiment, an exhaust process is performed, and water vapor in the furnace body 62 is released by an exhaust mechanism 90 with a heating furnace. This evacuation process is also preferably carried out throughout the heating process. In addition, the dehumidifying mechanism with a heating furnace 100 disposed on the ceiling of the furnace body 62 absorbs water vapor by the water absorbing material 102 and dehumidifies the inside of the furnace body 62. Since dew condensation is likely to occur particularly on the furnace wall including the ceiling of the furnace body 62, it is effective for dehumidification that the dehumidifying mechanism 100 with the heating furnace is disposed on the ceiling of the furnace body 62.

  Thus, the manufacturing method of the three-dimensional structure 320 disclosed herein includes a preparation process for preparing the modeling tank 20 in which the modeling table 30 having air permeability is arranged, a modeling process, and the modeling tank 20 The three-dimensional structure 320 is heated. Since the modeling table 30 has air permeability, ventilation is performed in the modeling tank 20 in the heating process, and the accumulation of heat and steam is alleviated. Thereby, unintentional solidification of the material powder 300 is suppressed.

  The modeling table 30 may be at least partially configured from a porous plate 32 having air permeability. Since the modeling table 30 is a member on which modeling is performed, the modeling table 30 is required not only to have air permeability but also to be loaded with the material powder 300. The porous plate 32 having air permeability can meet such a demand.

  Moreover, you may implement the ventilation process which sends air in the modeling tank 20 through the modeling table 30 in the predetermined time in a heating process. The ventilation process further promotes ventilation in the modeling tank 20 and suppresses unintentional solidification of the material powder 300.

  The heating process may be performed by a microwave heating method. According to the heating method using microwaves, water can be selectively and rapidly heated, so that the time required for the heating step can be shortened.

  In the heating method using microwaves, an exhaust process for exhausting the air in the modeling tank 20 may be performed at a predetermined time during the heating process. Furthermore, the heating step may be accompanied by a dehumidifying step of removing water vapor in the modeling tank 20 by the water absorbing substance 102. In the microwave heating method, dew condensation is likely to occur in the furnace body 62, but dew condensation can be prevented by performing an exhaust process and a dehumidifying process during the heating process to remove water vapor. By preventing condensation, it is possible to prevent water that has become water droplets due to condensation from causing unintentional solidification of the material powder 300 again.

  The modeling tank 20 and the modeling table 30 may be configured to be detachable from the three-dimensional modeling apparatus 10. When the modeling tank 20 in which the three-dimensional model 320 is accommodated is removed from the three-dimensional modeling apparatus 10 and put into the heating furnace 60 after the modeling process is finished, the modeling tank 20 in which the modeling table 30 is arranged is provided. If it is configured to be detachable from the three-dimensional modeling apparatus 10, workability is good. Moreover, when moving from the three-dimensional modeling apparatus 10 to the heating furnace, the risk of breaking the three-dimensional modeled object 320 by the moving operation can be reduced.

  As mentioned above, embodiment which included the heating furnace 60 by a microwave heating system was described as preferable one Embodiment in the manufacturing method of this three-dimensional structure. However, as a matter of course, the heating method of the three-dimensional structure 320 is not limited to the microwave heating method. The heating step may be performed by a heating method using heat. The method of heating by generating heat is a very common method, and is possible with a commercially available thermostat or a band heater. Therefore, it is easy to use existing facilities and the controllability is good.

  In the heating process using the heating method described above, a suction process of sucking air in the modeling tank 20 through the modeling table 30 may be performed at a predetermined time. In the heating method using heat, the drying time can be shortened by interweaving the blowing process and the suction process during the heating process.

  Hereinafter, an embodiment including a heating method using heat will be described with reference to FIG. FIG. 4 is a cross-sectional view of the heating furnace 60 provided with a heater as viewed from the front. The heater 66 with a heating furnace is, for example, a heating wire heater. The heating furnace 60 includes a stirrer 68 with a heating furnace. The stirrer 68 with a heating furnace sends the heat generated by the heater 66 with a heating furnace into the furnace body 62 as hot air, and stirs the air in the furnace body 62. The stirrer 68 with a heating furnace is, for example, a motor-driven blower. A temperature measuring unit such as a thermocouple 70 is installed in the furnace body 62, and the furnace temperature is controlled based on the measured temperature measured by the thermocouple 70 and the set temperature. When the bonding agent is PVA as in this embodiment, the furnace temperature is about 75 ° C., for example. This hot air heating tends to take a longer drying time than the above-described microwave heating. For example, a sample drying time of about 30 minutes in the microwave method is 120 minutes or longer in hot air drying. Of course, this is an example, and the actual time varies depending on the size of the three-dimensional structure 320, the size of the modeling tank 20, and the like. In any case, hot air heating tends to require drying time instead of microwave heating, instead of simple equipment and good controllability, so it is more preferable if the drying time can be shortened. Reference numeral 110 in FIG. 4 denotes a suction unit with a heating furnace. The suction unit 110 with a heating furnace sucks air in the modeling tank 20 through the air-permeable modeling table 30. The air blowing process by the heating furnace-equipped blower 80 and the suction process by the suction machine 110 are alternately performed through the air blowing port 82, and the switching is performed by the direction switching valve 112. When the blower 80 with a heating furnace is a fan, switching between blowing and suction may be performed in the rotation direction of the fan. The switching time is, for example, about every 10 minutes. By this suction, water vapor generated by heating is efficiently discharged out of the modeling tank 20, and the time required for drying is shortened. According to the inventor's experiment, when drying was performed for about 120 minutes by hot air drying and blowing, a sample that was insufficiently dried could be sufficiently dried in a drying time of 120 minutes by using suction together. In addition, although this inventor tried also implementing the method of performing only attraction | suction during a heating process, the material powder 300 is solidified, heat and a vapor | steam accumulation generate | occur | produce in the lower part of the modeling tank 20, and conversely the material powder 300 Induced unintentional solidification. Therefore, it is desirable to balance the air blowing process and the suction process.

  By the way, this inventor discovered that there exist dispersion | variation with the place in the modeling tank 20 about the effect at the time of suppressing the unintended solidification of the material powder 300 by this method. That is, the upper part of the place where the three-dimensional structure 320 exists in the lower part of the modeling tank 20 is relatively thin, and the upper part of the place where the three-dimensional structure 320 does not exist in the lower part of the modeling tank 20. Discovered that the effect of solidification suppression is relatively high. And it discovered that this dispersion | variation arises because a difference appears in the ease of air passage by the presence or absence of the three-dimensional structure 320. FIG.

  Moreover, this inventor discovered that the three-dimensional structure 320 may be warped by a heating process. And it discovered that this curvature occurred because a difference arises in a drying condition by the upper part in the modeling tank 20, and the lower part.

  Therefore, in the manufacturing method of the three-dimensional structure 320 disclosed herein, the first laying step of laying the material powder 300 on the shaping table 30 is performed after the preparation step and before the shaping step. Also good.

  Furthermore, after the modeling process, before the heating process, a second laying process may be performed in which the material powder 300 is further laid on the material powder layer that is finally stacked in the modeling process.

  The first laying step is a step that is performed after the preparation step and before the shaping step, and spreads the material powder 300 on the shaping table 30. Hereinafter, the material powder 300 spread on the lower portion of the modeling tank 20 in the first spread step is referred to as a lower support powder 302. The lower support powder 302 is a material powder 300 located below the three-dimensional structure 320 in FIGS. 3 and 4. The lower support powder 302 is supplied from the material powder 300 stored in the material tank 42, for example. The method for supplying the material powder 300 is the same as the method for supplying the material powder 300 in the modeling process. That is, in the first laying step, first, the modeling table 30 is moved downward D in the modeling tank 20 by the first lifting mechanism 40. However, the movement amount of the modeling table 30 at this time is, for example, about 10 mm. If the thickness of the lower support powder 302 is about 10 mm, the passage of air in the lower part of the modeling tank 20 can be made uniform to the required degree. Hereinafter, the bottom 42a of the material tank 42 is moved upward U in the material tank 42 by the second lifting mechanism 44, and the overflowing material powder 300 is smoothed on the modeling table 30 by the roller 46, as in modeling. It is. By this series of operations, a lower support powder layer having a predetermined thickness of about 10 mm is formed on the modeling table 30. In addition, according to the above-mentioned description, the material supply in the first laying step is performed once, but when it cannot be performed once, the material may be divided into several times. The material supply is not limited to the one performed by the three-dimensional modeling apparatus 10. For example, the material powder 300 prepared by the operator outside may be supplied.

  The second laying step is a step in which the material powder 300 is further laid on the material powder layer that is finally stacked in the shaping step after the shaping step and before the heating step. The second laying step is also performed by the same operation as the first laying step, and the thickness of the material powder 300 to be laid is about 10 mm. Hereinafter, the material powder 300 laid by the second laying step is referred to as an upper support powder 304. 3 and 4, the upper support powder 304 exists above the three-dimensional structure 320 in the modeling tank 20.

  The variation depending on the location of the solidification suppression effect of the material powder 300 in the modeling tank 20 is due to the difference in the ease of air passage depending on the presence or absence of the three-dimensional modeled object 320 in the lower part of the modeling tank 20. Therefore, by making the ease of air passage in the lower part of the modeling tank 20, variation due to the location of the solidification suppressing effect can be reduced. According to the first laying step, the lower support powder 302 is laid on the lower part of the modeling tank 20, so that the air passage at the lower part of the modeling tank 20 is made uniform. Thereby, the dispersion | variation by the place of the solidification suppression effect of the material powder 300 is suppressed.

  In addition, the cause of the warp of the three-dimensional structure 320 is that a difference occurs in the drying condition between the upper part and the lower part in the modeling tank 20. Therefore, the warpage of the three-dimensional structure 320 can be reduced by reducing the difference in the degree of drying between the upper part and the lower part of the modeling tank 20. By laying the upper support powder 304 on the upper part of the modeling tank 20 by the second laying step, the three-dimensional structure 320 is positioned near the center of the material powder 300 in the modeling tank 20. Thereby, the difference of the drying condition of the three-dimensional structure 320 between the upper part and the lower part of the modeling tank 20 in the heating process can be reduced, and the problem that the three-dimensional structure 320 is warped can be suppressed.

  In the above, the manufacturing method of the three-dimensional structure which suppresses unintentional solidification of the material powder in a heating process was demonstrated. Below, based on the said method, the three-dimensional modeling apparatus which suppresses the unintended solidification of the material powder in a heating process is demonstrated. The three-dimensional modeling apparatus described below includes the embodiment of the three-dimensional modeling apparatus 10 described with reference to FIGS. 1 and 2. Therefore, the same reference numerals are used for the members described so far in the following description. However, since the members and processes involved in the preparation process and the modeling process are the same as the members and processes described so far, the description thereof is omitted.

  The three-dimensional modeling apparatus 10 disclosed herein includes a modeling tank 20 and a modeling table 30 that is disposed in the modeling tank 20 and has air permeability. Since the modeling table 30 has air permeability, the material powder 300 in the modeling tank 20 is ventilated in the heat drying of the three-dimensional structure 320, and unintentional solidification of the material powder 300 is suppressed.

  FIG. 5 is a cross-sectional view of an embodiment of a three-dimensional modeling apparatus provided with a mechanism that suppresses unintentional solidification of the material powder 300 in the heating process, as viewed from the front. The three-dimensional modeling apparatus 10 includes a modeling tank 20 and a modeling table 30 having air permeability. The main part of the modeling table 30 is a breathable porous plate, and the material thereof is, for example, a plastic sintered body such as polypropylene or a ceramic sintered body. The three-dimensional modeling apparatus 10 includes a heating mechanism 160, a blower 180, an exhaust mechanism 190, a dehumidifying mechanism 200, and a tank moving mechanism 220. The heating mechanism 160 includes a cover 162, a microwave irradiation mechanism. 164. The modeling tank 20 is moved to the right R by the tank moving mechanism 220 during heating, and is stored in the cover 162 of the heating mechanism 160. The tank moving mechanism 220 includes, for example, a guide rail 222 laid under the modeling tank 20 and includes a mechanism for moving the modeling tank 20 with a motor and a drive unit using a ball screw. In the present embodiment, the modeling tank 20 moves into the cover 162, but the three-dimensional modeling apparatus 10 proposed here is not limited to such an embodiment. For example, the heating mechanism 160 may move toward the modeling tank 20, or the cover 162 covers the modeling tank 20 from the beginning, and the ejection head 48 and other members are retracted from the cover 162 during heating. It may be. The cover 162 is provided mainly for the safety of the operator, shields microwaves, and prevents diffusion of high-temperature water vapor. The microwave irradiation mechanism 164 is installed above the cover 162 and can irradiate the modeling tank 20 with microwaves. As described in the description of the manufacturing method, the output of the microwave irradiation mechanism 164 is about 50 W, for example. The blower 180 is connected to the lower part of the modeling table 30. The blower 180 is an electric fan, for example. The blower 180 is controlled so as to send air into the modeling tank 20 through the modeling table 30 with a predetermined air volume at a predetermined time during heating. The exhaust mechanism 190 is attached to the ceiling of the cover 162. However, the position where the opening of the exhaust mechanism 190 is attached is not limited to the ceiling of the cover 162, and the attachment direction is not limited to the vertical attachment. The exhaust mechanism 190 only needs to be provided with an opening in the space above the modeling tank 20 so that water vapor generated from the modeling tank 20 can be exhausted. The exhaust mechanism 190 is, for example, an exhaust pump or an exhaust fan. Alternatively, it may be a pipe connected to an exhaust facility of a building. The dehumidifying mechanism 200 includes a water-absorbing substance 202 such as a water-absorbing polymer, and a holding component 204 that holds the water-absorbing substance 202 and fixes the water-absorbing substance 202 to the cover 162, and is disposed on the entire ceiling of the cover 162.

  As described above, the three-dimensional modeling apparatus 10 according to the present embodiment includes the heating mechanism 160 and can perform a heating process. In the present embodiment, when performing the heating step, the modeling tank 20 is moved into the cover 162 of the heating mechanism 160 by the tank moving mechanism 220. After the modeling tank 20 is moved into the cover 162, microwaves are irradiated toward the modeling tank 20 by the microwave irradiation mechanism 164, and heating is started. In the initial stage of heating, the output of the microwave is set to a low output that does not break the shape of the three-dimensional structure 320, and is set to increase the output stepwise. For example, the output is about 30 W in the first half and about 50 W in the second half. The temperature of the three-dimensional structure 320 is adjusted to about 50 ° C to 70 ° C. During heating, the blower 180 blows air into the modeling tank 20 through the modeling table 30. This blowing is preferably performed throughout the heating process, and the air volume is such that the material powder 300 in the modeling tank 20 is not blown away. Further, during heating, the exhaust mechanism 190 exhausts air containing water vapor in the cover 162. The dehumidifying mechanism 200 adsorbs water vapor by the water-absorbing substance 202 and dehumidifies the inside of the cover 162. Thus, the exhaust mechanism 190 and the dehumidifying mechanism 200 remove water vapor in the cover 162. In this way, the three-dimensional structure forming apparatus 10 dries the three-dimensional structure 320 while suppressing unintentional solidification of the material powder 300 by ventilation and dehumidification.

  As described above, the three-dimensional modeling apparatus 10 includes the modeling tank 20 and the modeling table 30 disposed in the modeling tank 20 and having air permeability. By aeration from the modeling table 30 into the modeling tank 20, unintended solidification of the material powder 300 in the heat drying of the three-dimensional model 320 can be suppressed.

  The modeling table 30 may be at least partially configured from a porous plate 32 having air permeability. The porous plate 32 having air permeability is suitable for a main part of the modeling table 30.

  Further, the above-described three-dimensional modeling apparatus 10 may include a heating mechanism 160 that heats the three-dimensional modeled object 320 in the modeling tank 20. The heating mechanism 160 may be a heating mechanism that heats the three-dimensional structure 320 with microwaves. By providing the heating mechanism 160, the three-dimensional modeling apparatus 10 can perform a heating process, and the time required for drying the three-dimensional model 320 by adopting a heating method using a microwave as the heating method. Can be shortened.

  Furthermore, the above-described three-dimensional modeling apparatus 10 may include a blower 180 that blows air into the modeling tank 20 through the modeling table 30. By ventilation into the modeling tank 20 by the blower 180, ventilation in the modeling tank 20 is further improved, and unintentional solidification of the material powder 300 can be further suppressed.

  Further, the three-dimensional modeling apparatus 10 may include an exhaust mechanism 190 opened in a space above the modeling tank 20, and a dehumidifying mechanism 200 including a water absorbing substance 202 in the space above the modeling tank 20. It may be. By the exhaust mechanism 190 and the dehumidifying mechanism, the inside of the cover 162 is dehumidified and condensation can be prevented.

  According to a preferred embodiment different from the above-described embodiment of the three-dimensional modeling apparatus 10, the heating mechanism 160 may be a heating mechanism that heats the three-dimensional structure 320 with heat. According to the embodiment in which the three-dimensional structure 320 is heated by heat, the apparatus is simple and control is easy.

  In the embodiment in which the three-dimensional structure 320 is heated by heat, the three-dimensional structure forming apparatus 10 may include a suction device 210 that sucks air in the modeling tank 20 through the modeling table 30. As described above, in the embodiment in which the three-dimensional structure 320 is heated with heat, the time required for drying can be shortened by alternately performing air blowing and suction.

  FIG. 6 is a cross-sectional view of the three-dimensional modeling apparatus 10 provided with a heater in the heating mechanism 160 as viewed from the front. In FIG. 6, a band heater 166 is wound around the side surface of the modeling tank 20. The three-dimensional structure 320 in the modeling tank 20 is heated by the band heater 166 and dried. If a direct heating method using a heater or the like is employed as the heating method of the heating mechanism 160, the mechanism of the three-dimensional modeling apparatus 10 can be further simplified as compared with the hot air method. For example, in the embodiment of FIG. 6, there is no tank moving mechanism. In addition, a stirrer is unnecessary.

  As mentioned above, although embodiment was described, the manufacturing method and three-dimensional modeling apparatus which concern on this application are not restricted to embodiment described above.

DESCRIPTION OF SYMBOLS 10 3D modeling apparatus 20 Modeling tank 30 Modeling table 60 Heating furnace 64 Microwave irradiation mechanism with heating furnace 66 Heater with heating furnace 80 Blower with heating furnace 90 Exhaust mechanism with heating furnace 100 Dehumidification mechanism with heating furnace 102 Water absorption substance 110 Heating furnace Attached suction device 160 Heating mechanism 164 Microwave irradiation mechanism 166 Band heater 180 Blower 190 Exhaust mechanism 200 Dehumidification mechanism 202 Water absorbing substance 210 Suction machine 300 Material powder 302 Lower support powder 304 Upper support powder 320 Three-dimensional structure

Claims (19)

A preparation step of preparing a modeling tank in which a modeling table having air permeability is arranged;
The material powder is laid on the modeling table to a predetermined thickness, and the material powder at the predetermined position is discharged by discharging a hardening liquid to a predetermined position on the laid material powder. A one-dimensional material powder layer bonded to each other is formed, and the material powder layer is stacked one layer at a time in the modeling tank, thereby forming a predetermined three-dimensional structure in the material powder in the modeling tank. Modeling process to model,
After the modeling process, a heating process for heating the three-dimensional modeled object in the modeling tank;
Having
A manufacturing method of a three-dimensional structure. At a predetermined time during the heating step, it has a blowing step of sending air into the modeling tank through the modeling table.
The manufacturing method of the three-dimensional structure according to claim 1. After the preparatory step, before the modeling step, has a first laying step of laying the material powder on the modeling table,
The manufacturing method of the three-dimensional structure according to claim 1 or 2. After the modeling step, before the heating step, a second laying step of further laying the material powder on the material powder layer last stacked in the modeling step,
The manufacturing method of the three-dimensional structure according to any one of claims 1 to 3. The heating step is performed by a microwave heating method.
The manufacturing method of the three-dimensional structure as described in any one of Claims 1-4. An exhaust process for exhausting the air in the modeling tank at a predetermined time during the heating process;
The manufacturing method of the three-dimensional structure according to claim 5. The heating step involves a dehumidifying step of removing water vapor in the modeling tank with a water-absorbing substance.
The manufacturing method of the three-dimensional structure according to claim 5 or 6. The heating step is performed by a heating method using heat.
The manufacturing method of the three-dimensional structure as described in any one of Claims 1-4. At a predetermined time during the heating step, it has a suction step of sucking air in the modeling tank through the modeling table.
The manufacturing method of the three-dimensional structure according to claim 8. A modeling tank,
A modeling table having air permeability, disposed in the modeling tank;
With
3D modeling equipment. The modeling table is composed of a porous plate having at least a part of air permeability,
The three-dimensional modeling apparatus according to claim 10. Provided with a heating mechanism for heating the three-dimensional structure in the modeling tank,
The three-dimensional modeling apparatus according to claim 11 or 12. A blower for blowing air into the modeling tank through the modeling table,
The three-dimensional modeling apparatus according to claim 12. The heating mechanism is a heating mechanism that heats the three-dimensional structure by microwaves.
The three-dimensional modeling apparatus according to claim 12 or 13. An exhaust mechanism opened toward the space above the modeling tank,
The three-dimensional modeling apparatus according to claim 14. A dehumidifying mechanism provided with a water-absorbing substance was provided in the space above the modeling tank,
The three-dimensional modeling apparatus according to claim 14 or 15. The heating mechanism is a heating unit that heats the three-dimensional structure with heat.
The three-dimensional modeling apparatus according to claim 12 or 13. With a suction machine that sucks air in the modeling tank through the modeling table,
The three-dimensional modeling apparatus according to claim 17. The modeling tank and the modeling table are configured to be detachable from the three-dimensional modeling apparatus.
The three-dimensional modeling apparatus according to claim 10 or 11.

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