JP2018154047A - Three-dimensional molding apparatus, method for manufacturing three-dimensional molded article and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a small-sized three-dimensional molding apparatus in which an excess powder is produced that passes in a molding tank during a flattening process.SOLUTION: A three-dimensional molding apparatus is provided for manufacturing a three-dimensional molded article by repeating such an operation that includes forming a powder layer 31 in a molding tank by carrying out a flattening process in which a powder 20 reserved in a supply tank 21 is conveyed to a molding tank 22 by moving a flattening member 12 as well as the powder in the molding tank is flattened, and binding the powder of the powder layer into a desired shape to form a layer structure 30, so as to stack the layer structures. An excess powder return process is carried out by moving a powder returning member 12 to follow the movement route of the flattening member, so as to return at least a part of an excess powder conveyed by the flattening member to pass over the molding tank back to the supply tank.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a three-dimensional modeling apparatus, a method for manufacturing a three-dimensional modeled object, and a program.

  Conventionally, the powder stored in the supply tank is transferred and supplied to the modeling tank by moving the flattening member, and the leveling process for flattening the powder in the modeling tank is performed, and the powder is formed in the modeling tank. There is known a three-dimensional modeling apparatus that forms a three-dimensional structure in which a layered structure is laminated by repeatedly performing an operation of forming a layered structure by combining powder of a powder layer into a required shape.

  For example, in Patent Document 1, a leveling roller (a leveling member) is moved horizontally to transfer and supply powder from a supply tank to a modeling tank, and a leveling process is performed to level the powder in the modeling tank. A three-dimensional modeling apparatus is known. In this three-dimensional modeling apparatus, surplus powder transferred until it passes through the modeling tank by the leveling roller during the leveling process falls into the excess powder receiving tank and is collected.

  In the conventional 3D modeling apparatus, each time a single layer of powder is formed, surplus powder is accumulated in the surplus powder receiving tank, so a large surplus powder receiving tank is required, and the apparatus becomes larger. .

  In order to solve the above-described problems, the present invention moves the flattening member to transfer and supply the powder stored in the supply tank to the modeling tank, and flatten the powder in the modeling tank. A three-dimensional structure in which the layered structure is laminated by repeatedly performing an operation of performing a flattening process and combining the powder of the powder layer formed in the modeling tank into a required shape to form a layered structure. It is a three-dimensional modeling apparatus that models a modeled object, and the surplus that has been transferred by the flattening member until it passes through the modeling tank by moving the powder return member so as to return the movement path of the flattening member A surplus powder returning process for returning at least a part of the powder to the supply tank is performed.

  According to the present invention, it is possible to reduce the size of the three-dimensional modeling apparatus in which surplus powder that passes through the modeling tank is generated during the planarization process.

It is plane explanatory drawing which shows the outline of an example of the three-dimensional modeling apparatus which concerns on 1st Embodiment. It is side surface explanatory drawing which shows the outline of the same three-dimensional modeling apparatus. It is sectional explanatory drawing which shows the outline of the modeling part in the same three-dimensional modeling apparatus. It is an isometric view explanatory drawing which shows the specific structure of the principal part of the same three-dimensional modeling apparatus. It is a block diagram which shows the control part in the same three-dimensional modeling apparatus. (A)-(e) is explanatory drawing for demonstrating the formation operation | movement (planarization process of an outward path) at the time of the outward path | route of the flattening roller which reciprocates in the three-dimensional modeling apparatus. (A)-(c) is explanatory drawing for demonstrating the formation operation | movement (planarization process of a return path) at the time of the return path | route of the flattening roller which reciprocates in the same three-dimensional modeling apparatus.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
An outline of an example of the three-dimensional modeling apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
FIG. 1 is an explanatory schematic plan view of the 3D modeling apparatus, FIG. 2 is an explanatory schematic side view, and FIG. 3 is an explanatory sectional view of the modeling unit. FIG. 3 shows a state during modeling. FIG. 4 is an explanatory perspective view of the essential part of the specific configuration.

  This three-dimensional modeling apparatus is a powder modeling apparatus (also referred to as a powder modeling apparatus), and is formed into a layered structure 1 in which a layered structure 30 to which powder (powder) is bonded is formed, and a layered structure of the modeling part 1. A modeling unit 5 that discharges the modeling liquid 10 to the spread powder layer (powder layer) 31 is provided.

  The modeling unit 1 includes a powder tank 11 and a flattening roller 12 which is a rotating member as a flattening member constituting a flattening means (recoater). The flattening member may be a plate-like member (blade) instead of the rotating member.

  The powder tank 11 is supplied to the supply tank 21 for storing the powder 20 to be supplied to the modeling tank 22, the modeling tank 22 in which the layered structure 30 is stacked to form a three-dimensional structure, and the modeling tank 22. A surplus powder receiving mechanism 80 provided with a powder holding table 81 as a powder holding member for temporarily holding surplus powder.

  The supply stage 23 constituting the bottom of the supply tank 21 can be raised and lowered in the vertical direction (height direction). Similarly, the modeling stage 24 constituting the bottom of the modeling tank 22 can also be raised and lowered in the vertical direction (height direction). A three-dimensional structure in which the layered structure 30 is stacked on the modeling stage 24 is modeled. For example, as shown in FIG. 4, the supply stage 23 is raised and lowered in the Z direction (height direction) by the motor 27, and the modeling stage 24 is also raised and lowered in the Z direction by the motor 28.

  The side surface of the supply stage 23 is disposed in contact with the inner side surface of the supply tank 21. The side surface of the modeling stage 24 is also arranged so as to contact the inner surface of the modeling tank 22. The upper surfaces of the supply stage 23 and the modeling stage 24 are kept horizontal.

  A powder supply device 554 described later is disposed in the supply tank 21. During the initial modeling operation or when the amount of powder in the supply tank 21 decreases, the powder in the tank constituting the powder supply device 554 is supplied to the supply tank 21. Examples of the powder conveying method for supplying powder include a screw conveyor method using a screw and an air transportation method using air.

  The flattening roller 12 transports and supplies the powder 20 stored on the supply stage 23 of the supply tank 21 to the modeling tank 22 and leveles the surface of the powder 20 supplied to the modeling tank 22. Flatten to form a powder layer having a predetermined thickness. The axial length of the flattening roller 12 is longer than the inner dimension width of the modeling tank 22 and the supply tank 21, and in the Y direction along the stage surface of the modeling stage 24 (the surface on which the powder 20 is loaded), The reciprocating mechanism is arranged so as to be able to reciprocate relative to the stage surface, and is moved by the reciprocating mechanism 25.

  Further, the flattening roller 12 is rotationally driven by a motor 26. The flattening roller 12 reciprocates in the horizontal direction so as to pass above the supply tank 21 and the modeling tank 22 while being rotated by the motor 26. As a result, the powder 20 in the supply tank 21 is transported and supplied to the modeling tank 22, and the flattening roller 12 is flattened while transporting the powder 20 while passing over the modeling tank 22, and has a desired thickness. A powder layer 31 is formed.

  The modeling unit 5 discharges (applies) the modeling liquid 10 for binding the powder 20 to the powder layer 31 on the modeling stage 24 to form a layered structure 30 as a layered structure to which the powder 20 is bound. A liquid discharge unit 50 is provided.

  The liquid discharge unit 50 includes a carriage 51 and two (or three or more) liquid discharge heads (hereinafter simply referred to as “heads”) 52 a and 52 b mounted on the carriage 51.

  The carriage 51 is movably held by the guide members 54 and 55. The guide members 54 and 55 are held on both side plates 70 and 70 so as to be movable up and down. The carriage 51 is reciprocated in the X direction, which is the main scanning direction, via a pulley and a belt by an X direction scanning motor constituting an X direction scanning mechanism 550 described later.

  The two heads 52a and 52b (hereinafter referred to as “heads 52” when not distinguished from each other) are each provided with two nozzle rows in which a plurality of nozzles that discharge the modeling liquid 10 are arranged. The two nozzle rows of one head 52a discharge a cyan modeling liquid and a magenta modeling liquid. The two nozzle rows of the other head 52b discharge yellow modeling liquid and black modeling liquid, respectively. The head configuration is not limited to this.

  A plurality of tanks 60 containing each of these cyan modeling liquid, magenta modeling liquid, yellow modeling liquid, and black modeling liquid are mounted on the tank mounting portion 56 and supplied to the heads 52a and 52b via supply tubes and the like.

  A maintenance mechanism 61 that performs maintenance and recovery of the head 52 of the liquid ejection unit 50 is disposed on one side in the X direction. The maintenance mechanism 61 is mainly composed of a cap 62 and a wiper 63. In the maintenance mechanism 61, the cap 62 is brought into close contact with the nozzle surface (surface on which the nozzle is formed) of the head 52, and the modeling liquid is sucked from the nozzle. This is for discharging the powder clogged in the nozzle and discharging the modeling liquid having a high viscosity. Thereafter, the maintenance mechanism 61 wipes (wipes) the nozzle surface with the wiper 63 in order to form a meniscus for the nozzle. Further, the maintenance mechanism 61 covers the nozzle surface of the head with the cap 62 during a period in which the modeling liquid is not discharged, and prevents the powder 20 from being mixed into the nozzle and the modeling liquid 10 from being dried.

  The modeling unit 5 has a slider portion 72 movably held by a guide member 71 disposed on the base member 7, and the entire modeling unit 5 reciprocates in the Y direction (sub-scanning direction) orthogonal to the X direction. Is possible. The modeling unit 5 is reciprocated in the Y direction as a whole by a Y-direction scanning mechanism 552 described later.

  The liquid discharge unit 50 is disposed so as to be movable up and down in the Z direction together with the guide members 54 and 55, and is moved up and down in the Z direction by a Z direction lifting mechanism 551 described later.

Next, an outline of the control unit of the three-dimensional modeling apparatus in the present embodiment will be described with reference to FIG.
FIG. 5 is a block diagram of the control unit.
The control unit 500 includes a CPU 501 that controls the entire three-dimensional modeling apparatus of the present embodiment, a program that includes a program for causing the CPU 501 to control the three-dimensional modeling operation, a ROM 502 that stores other fixed data, and a modeling A main control unit 500A including a RAM 503 for temporarily storing data and the like is provided.

  The control unit 500 includes a non-volatile memory (NVRAM) 504 for holding data even when the apparatus is powered off. Further, the control unit 500 includes an ASIC 505 that processes image processing for performing various signal processing on image data and other input / output signals for controlling the entire apparatus.

  The control unit 500 includes an external I / F 506 for transmitting and receiving data and signals used when receiving modeling data from the external modeling data creating apparatus 600. The modeling data creation apparatus 600 is an apparatus that creates modeling data obtained by slicing a final three-dimensional modeled object into each layered structure, and is configured by an information processing apparatus such as a personal computer. In addition, the control unit 500 includes an I / O 507 for taking in detection signals of various sensors. The I / O 507 receives a detection signal from a temperature / humidity sensor 560 that detects temperature and humidity as environmental conditions of the apparatus, and detection signals from other sensors.

  The control unit 500 includes a head drive control unit 508 that drives and controls the head 52 of the liquid ejection unit 50. In addition, the control unit 500 moves the carriage 51 of the liquid discharge unit 50 in the X direction (main scanning direction), a motor driving unit 510 that drives a motor constituting the X direction scanning mechanism 550, and the modeling unit 5 in the Y direction ( A motor driving unit 512 that drives a motor that constitutes the Y-direction scanning mechanism 552 that moves in the sub-scanning direction) is provided. In addition, the control unit 500 includes a motor drive unit 511 that drives a motor that constitutes a Z-direction lifting mechanism 551 that moves (lifts) the carriage 51 of the liquid ejection unit 50 in the Z direction. In addition, raising / lowering to the arrow Z direction can also be set as the structure which raises / lowers the modeling unit 5 whole.

  The control unit 500 includes a motor drive unit 513 that drives a motor 27 that raises and lowers the supply stage 23, and a motor drive unit 514 that drives a motor 28 that raises and lowers the modeling stage 24. The control unit 500 includes a motor drive unit 515 that drives a motor 553 of the reciprocating mechanism 25 that moves the flattening roller 12, and a motor drive unit 516 that drives a motor 26 that rotationally drives the flattening roller 12. Yes.

  The control unit 500 includes a supply system drive unit 517 that drives the powder supply device 554 that supplies the powder 20 to the supply tank 21, a maintenance drive unit 518 that drives the maintenance mechanism 61 of the liquid discharge unit 50, and a surplus described later. And a mechanism drive unit 519 for driving the slide member 83 of the powder receiving mechanism 80.

  An operation panel 522 for inputting and displaying necessary information is connected to the control unit 500.

Next, the configuration and operation of the excess powder receiving mechanism 80 will be described with reference to FIGS.
As shown in FIGS. 2 and 3, the surplus powder receiving mechanism 80 is attached to the powder holding table 81, a support shaft 82 extending downward from the bottom surface of the powder holding table 81, and the support shaft 82. And a slide member 83.

  On the other hand, the modeling stage 24 is provided with a stage rack 24a extending downward from the bottom surface thereof. The stage rack 24a has teeth formed in a sawtooth shape or a wave shape along the vertical direction. Each tooth is formed such that the upper surface is substantially horizontal and the lower surface is inclined with respect to the horizontal plane.

  The slide member 83 is supported such that the tip thereof is supported by the upper tooth surface of the stage rack 24 a of the modeling stage 24. Thereby, the support shaft 82 and the powder holding table 81 to which the slide member 83 is attached are supported, and the powder holding table 81 can be raised and lowered in conjunction with the raising and lowering of the modeling stage 24.

  The slide member 83 is attached to the support shaft 82 so as to be slidable in a direction in which the slide member 83 comes into contact with or separates from the stage rack 24a. The slide member 83 is biased in a direction in contact with the stage rack 24a by a biasing means such as a spring.

  When the modeling stage 24 descends in a state where the tip of the slide member 83 is supported by any upper tooth surface (substantially horizontal surface) of the stage rack 24a, the slide member 83 is moved to the stage rack 24a by its own weight of the excess powder receiving mechanism 80. Then, the powder holding table 81 is also lowered. Then, when the bottom surface of the powder holding table 81 is lowered in conjunction with the stopper 24 b provided on the outer wall surface of the modeling tank 22, the lowering of the powder holding table 81 and the slide member 83 is restricted.

  At this time, the slide member 83 is pushed against the urging force of the urging means by the lower tooth surface (inclined surface) of the descending stage rack 24a, and slides along the lower tooth surface (inclined surface) of the stage rack 24a. The tip of the member 83 moves (slids) relatively. Thereby, the front end of the slide member 83 gets over the lower tooth surface (inclined surface) of the stage rack 24a, and the upper tooth surface on which the front end of the slide member 83 is supported is switched to the next upper tooth surface (substantially horizontal surface).

Next, the operation of forming the powder layer in the present embodiment will be described with reference to FIG.
6A to 6E are explanatory views for explaining the powder layer forming operation (outward path flattening process) during the forward path of the flattening roller 12 that reciprocates.
First, as illustrated in FIG. 6A, it is assumed that one or a plurality of layered structures 30 are formed on the modeling stage 24 of the modeling tank 22. At this time, the height of the holding surface (upper surface) of the powder holding table 81 of the surplus powder receiving mechanism 80 is equal to the height of the upper surface of the previous powder layer 31 (upper surface of the uppermost layered structure 30). I'm doing it.

  As shown in FIG. 6B, when forming the next powder layer 31 on the uppermost layered structure 30, the head 52 is retracted to the home position and the modeling stage 24 of the modeling tank 22 is moved in the Z2 direction. To lower. In conjunction with this, the powder holding table 81 of the surplus powder receiving mechanism 80 is also lowered in the Z2 direction.

  At this time, when the powder holding table 81 is lowered by the movement amount z5, the bottom of the powder holding table 81 comes into contact with the stopper 24b of the modeling tank 22 and the lowering is restricted. Therefore, the powder holding table 81 stops at a position lowered by the movement amount z5. In addition, this movement amount z5 is matched with the movement amount z4 when raising the modeling stage 24 of the modeling tank 22 next to Z1 direction, for example.

  On the other hand, as shown in FIG. 6C, the modeling stage 24 is further lowered in the Z2 direction even after the powder holding table 81 is regulated by the stopper 24b. As a result, the slide member 83 of the surplus powder receiving mechanism 80 is pushed in by the lower tooth surface (inclined surface) of the stage rack 24 a that descends integrally with the modeling stage 24, and the stage rack 24 a that supports the tip of the slide member 83. The upper tooth surface (substantially horizontal surface) is sequentially switched. When the modeling stage 24 is stopped at a position lowered by the movement amount z2, the tip of the slide member 83 is supported by the upper tooth surface of the corresponding stage rack 24a.

  Subsequently, as shown in FIG. 6D, the supply stage 23 of the supply tank 21 is raised by the amount of movement z1 in the Z1 direction. At this time, it is preferable to set the start of raising the supply stage 23 so that the raising of the supply stage 23 is completed at the same time when the lowering of the modeling stage 24 is completed.

  The movement amount z1 of the supply stage 23 and the movement amount z2 of the modeling stage 24 are set so as to form a pre-powder layer larger than the target thickness Δt of the powder layer 31 to be formed. The target thickness Δt is preferably about several tens to 100 μm, for example.

  Further, as shown in FIG. 6D, the flattening roller 12 is moved in the Y2 direction (the flattening direction of the outward path) from the supply tank 21 toward the modeling tank 22. At this time, the flattening roller 12 is rotationally driven in the direction of the arrow in the drawing, that is, in the direction in which the lower surface side of the flattening roller 12 moves in the same direction as the Y2 direction. In this way, the flattening roller 12 moves in the Y2 direction while rotating in the direction of the arrow in the drawing, so that the powder 20 existing above the upper surface level of the supply tank 21 is smoothly transferred in the Y2 direction and shaped. It can be supplied to the tank 22.

  Then, as shown in FIG. 6E, the surface of the powder 20 supplied to the modeling tank 22 when the flattening roller 12 further moves in the Y2 direction while rotating and passes above the modeling tank 22. The pre-powder layer 31 ′ having a thickness larger than the target thickness Δt of the finally formed powder layer 31 is formed.

  Here, in the present embodiment, the relationship between the movement amount z1 of the supply stage 23 and the movement amount z2 of the modeling stage 24 is a relationship of z1 ≧ z2. As a result, a sufficient amount of the powder 20 can be supplied from the supply tank 21 to the modeling tank 22 to spread the powder 20 on the entire modeling tank 22.

  At this time, surplus powder 20 ′ that is not supplied to the modeling tank 22 is generated in the powder 20 transferred from the supply tank 21, and the surplus powder 20 is transferred by the flattening roller 12 until it passes through the modeling tank 22. The The surplus powder falls onto the holding surface of the powder holding table 81 located below the upper surface level of the modeling tank 22 and is temporarily held.

  If such surplus powder 20 ′ is generated, the surplus amount is always obtained while the flattening roller 12 transfers the powder 20 to the downstream end of the modeling tank 22 in the Y2 direction from the supply tank 21 toward the modeling tank 22. Of powder. As a result of the presence of such surplus powder, the pressing effect of the powder layer due to the weight of the surplus powder can be obtained up to the downstream end of the modeling tank 22, and as a result, a more uniform high powder density powder. It is advantageous to form a body layer.

FIGS. 7A to 7C are explanatory views for explaining a powder layer forming operation (return path flattening process) during the return path of the flattening roller 12 that reciprocates.
When the forward flattening process for forming the pre-powder layer 31 ′ is completed as described above, subsequently, as shown in FIG. 7A, the supply stage 23 of the supply tank 21 is moved in the Z2 direction by the amount of movement z3. The modeling stage 24 of the modeling tank 22 is raised by the amount of movement z4 in the Z1 direction. Thereby, the powder 20 in the upper layer portion of the pre-powder layer 31 ′ formed on the modeling stage 24 of the modeling tank 22 by the above-described planarization process in the outward path has risen upward from the upper surface level of the modeling tank 22. become. The moving amount z4 of the modeling stage 24 at this time is set so that the distance between the upper surface of the lower powder layer 31 formed last time and the lowermost portion of the flattening roller 12 becomes the target thickness Δt1 of the powder layer 31. .

  In conjunction with the ascent of the modeling stage 24, the powder holding table 81 of the surplus powder receiving mechanism 80 is also raised by the moving amount z6 in the Z1 direction. This movement amount z6 is adjusted to, for example, the movement amount z5 when the powder holding table 81 is first lowered. Thereby, the height of the holding surface (upper surface) of the powder holding table 81 of the surplus powder receiving mechanism 80 coincides with the upper surface level of the modeling tank 22. As a result, the surplus powder 20 ′ generated on the forward flattening process and held on the holding surface of the powder holding table 81 also rises upward from the upper surface level of the modeling tank 22.

  Thereafter, as shown in FIG. 7B, the flattening roller 12 is moved in the Y1 direction (the flattening direction of the return path) from the powder holding table 81 to the supply tank 21 through the modeling tank 22. At this time, the flattening roller 12 is rotationally driven in the direction of the arrow in the drawing, that is, in the direction in which the lower surface side of the flattening roller 12 moves in the same direction as the Y1 direction. As described above, when the flattening roller 12 moves in the Y1 direction while rotating in the direction of the arrow in the drawing, the excess powder 20 'on the holding surface of the powder holding table 81 can be appropriately transferred in the Y1 direction. Further, the surface of the powder 20 in the modeling tank 22 is leveled and flattened while appropriately transferring the powder 20 existing above the upper surface level of the modeling tank 22 in the Y1 direction together with the surplus powder 20 ′. Can be As a result, a powder layer 31 having a target thickness Δt is formed in the modeling tank 22.

  Then, when the flattening roller 12 rotates and further moves in the Y1 direction and passes above the modeling tank 22, unused powders 20 and 20 ′ that are not used for forming the powder layer 31 are supplied to the supply tank. 21 is returned. The flattening roller 12 after the formation of the powder layer 31 passes over the supply tank 21 and returns (returns) to the initial position (origin position) as shown in FIG. Thereafter, returning to the operation shown in FIG. 6A, the droplet of the modeling liquid 10 is discharged from the head 52, and the layered structure 30 having a required shape is formed on the formed powder layer 31.

  In the layered structure 30, for example, the modeling liquid 10 discharged from the head 52 is mixed with the powder 20, whereby the adhesive contained in the powder 20 is dissolved, and the dissolved adhesives are bonded to each other. Thus, the powder 20 is formed by bonding. The new layered structure 30 and the layered structure 30 underneath it constitute a part of the three-dimensional structure.

  Thereafter, by repeating the above-described operation, a three-dimensional modeled object (three-dimensional modeled object) in which the layered structures 30 are stacked is modeled.

  In the present embodiment, in order to form a uniform powder layer 31 with as high a powder density as possible, the flattening roller 12 is moved back and forth to perform the flattening process twice in the forward path and the backward path. A single powder layer 31 is formed. Note that the number of times of planarization may be three or more. When a single powder layer 31 is formed by executing a plurality of planarization processes in this way, the density of the powder layer can be increased stepwise, and the powder layer made uniform with a high powder density It is advantageous to form 31.

  Here, in the case where it is intended to form the powder layer 31 that is made uniform at a high powder density by performing the flattening process a plurality of times in this way, the flattening process that is performed first (the flattening of the forward path) It is important to distribute a uniform amount of the powder 20 over the entire powder layer to be formed (the entire modeling tank 22) during processing. This is because if there is a portion where the amount of the powder 20 is insufficient, the density of the portion is likely to be insufficient even if a further flattening process is performed thereafter, and the density unevenness of the powder layer 31 is likely to occur. Therefore, in the present embodiment, during the flattening process of the outward path, surplus powder 20 ′ is generated so that a uniform amount of powder 20 is distributed over the entire powder layer to be formed (the entire modeling tank 22). Like to do.

  In the present embodiment, the interval between the upper surface of the lower powder layer 31 previously formed in the return path flattening process and the lowermost part of the flattening roller 12 is set to be narrower than that in the forward path flattening process. Therefore, in the return path flattening process, the surplus powder 20 ′ on the powder holding table 81 is returned to the supply tank 21, and the surplus powder returning process and the flattening process for flattening the powder 20 in the modeling tank 22 are performed. It is done in parallel.

  Not limited to this, the distance between the upper surface of the lower powder layer 31 formed last time and the lowermost portion of the flattening roller 12 may be set to be the same during the forward path and during the backward path. In this case, since the formation of the powder layer 31 is substantially completed by the flattening process in the forward path, the process during the return path is substantially only the surplus powder returning process.

  Even in this case, during the process of the return path, when the surplus powder 20 ′ on the powder holding table 81 passes through the modeling tank 22, the surplus powder 20 ′ is weighted by the movement of the flattening roller 12. While the pressing effect of the powder layer 31 is obtained, a part of the excess powder 20 ′ is included in the powder layer 31 and the powder density of the powder layer 31 is increased. Therefore, strictly speaking, in this case as well, it can be said that the surplus powder returning process and the flattening process are performed in parallel during the return path processing, but only the surplus powder returning process is practically performed.

  In the present embodiment, in order to return the excess powder 20 ′ on the powder holding table 81 to the supply tank 21 during the return path, as a powder return member that moves to return the movement path of the flattening roller 12 during the forward path, Although the flattening roller 12 in the forward path is used, a powder returning member may be provided separately from the flattening roller 12 in the forward path. The function of the flattening roller 12 in the forward path should be optimized for the flattening process in the forward path, and is therefore inappropriate for returning the excess powder 20 ′ on the powder holding table 81 to the supply tank 21. There is. By using a powder return member that is separate from the flattening roller 12 in the forward path, the surplus powder 20 ′ on the powder holding table 81 is supplied without being limited by the function of the flattening roller 12 in the forward path. A member optimized for returning to the tank 21 (for example, a member optimized in shape, surface state, etc.) can be used.

  In the present embodiment, the surplus powder 20 ′ on the powder holding table 81 is returned to the supply tank 21 during the return path, so that the surplus powder returning process is performed. The flattening roller 12 is moved in the Y1 direction while maintaining the lowermost part 12 at a height equal to or lower than the powder surface (upper surface of the pre-powder layer 31 ′) of the modeling tank 22 flattened during the forward path. Therefore, substantially the surplus powder 20 ′ on the powder holding table 81 is not newly supplied for forming the powder layer 31. That is, as described above, during the process of the return path, when the excess powder 20 ′ on the powder holding table 81 passes through the modeling tank 22, the powder density of the powder layer 31 is moved by the movement of the flattening roller 12. Only a part of the excess powder 20 ′ is supplied to the powder layer 31 by the amount of the increase in the amount of powder, but substantially the excess powder 20 ′ on the powder holding table 81 is used as the powder. It is not newly supplied for the formation of the layer 31.

  Further, in the present embodiment, it is configured that all of the excess powder 20 ′ on the powder holding table 81 is returned to the supply tank 21 during the return flattening process. A part of the excess powder 20 ′ may remain. Therefore, for example, the powder holding table 81 is provided with a side wall for preventing the excess powder 20 ′ from spilling or scattering, and as a result, a part of the excess powder 20 ′ remains on the powder holding table 81. You may end up doing it.

  In any case, as in the conventional three-dimensional modeling apparatus, the powder holding of this embodiment is compared with the configuration in which the surplus powder is accumulated in the surplus powder receiving tank each time one layer of powder is formed. The table 81 has a smaller maximum powder holding amount than the conventional surplus powder receiving tank, and can be downsized to, for example, 1/4 or less of the conventional surplus powder receiving tank.

  In the present embodiment, since a roller member such as the flattening roller 12 is used as the flattening member or the powder returning member, the powder is moved forward in the moving direction of the flattening member or the powder returning member during the flattening process. The contact surface (the lower front portion in the moving direction on the peripheral surface of the flattening roller 12) that contacts the bodies 20 and 20 ′ faces obliquely downward. Therefore, by moving the flattening member and the powder returning member, the contact surfaces cause the powders 20 and 20 'to move in the moving direction and generate a force for pushing downward. Therefore, the effect of increasing the powder density can be obtained by using such a flattening member or powder returning member.

  When such a flattening member or powder returning member is used, sliding between the contact surface and the powder 20, 20 ′ is reduced as the frictional force generated between the contact surface and the powder 20 is reduced. As a result of the occurrence of (slip), more powder 20 is likely to enter the lower side of the flattening roller 12. Therefore, in the present embodiment in which the contact surface that contacts the powder 20, 20 ′ is directed obliquely downward in front of the moving direction of the flattening member and the powder returning member, in the flattening process of the return path By reducing the frictional force, the effect of forming the powder layer 31 having a higher powder density can be obtained.

  Further, in this embodiment, a rotating member such as the flattening roller 12 is used as the flattening member or the powder returning member, and the direction of moving the surface on the lower surface side of the flattening member or the powder returning member is flattened. Rotation is driven so as to be the same as the moving direction of the member and the powder returning member. According to such a configuration, the frictional force between the peripheral surface of the flattening roller 12 and the powder 20 is always a dynamic frictional force, and the smoothness of the surface of the powder layer 31 can be improved.

  However, when adopting a configuration in which the flattening member and the powder returning member are rotated as described above, the powder 20 is easily rolled up during the flattening process. In this case, the rolled up powders 20 and 20 ′ fall on the surface of the powder layer after passing through the flattening member and the powder returning member, thereby reducing the smoothness of the powder layer surface and the density of the powder layer 31. There is a risk of causing a decrease in the modeling accuracy of the three-dimensional structure. However, in the forward path, even if the powder 20 is rolled up, the powder 20 that has fallen on the powder layer is collected during the return path, and therefore, the modeling accuracy of the three-dimensional structure is reduced. Absent. However, the winding of the powders 20 and 20 ′ that occurs during the return path is not collected thereafter and contributes to the formation of the layered structure 30, which may lead to a decrease in the modeling accuracy of the three-dimensional structure.

  Here, as the frictional force generated between the peripheral surface of the flattening roller 12 and the powder 20 increases, the powders 20, 20 ′ accompany the movement of the peripheral surface of the flattening roller 12 due to the rotation of the flattening roller 12. The amount of powder to be rolled up is increased. Conversely, as the frictional force generated between the peripheral surface of the flattening roller 12 and the powders 20 and 20 ′ is reduced, the amount of powder that is wound up can be reduced. In addition, since the amount of the powder 20 that has been wound up can be suppressed, it is possible to obtain the effects of reducing the wasteful consumption of the powder 20 and improving the recyclability of the powder 20.

  Therefore, by reducing the frictional force generated between the peripheral surface of the flattening roller 12 and the powder 20, 20 ′ during the return path, the modeling accuracy of the three-dimensional structure is reduced due to the winding of the powder 20, 20 ′. This can reduce the amount of powder 20 and 20 ′ wound up during the return path. Therefore, an effect of suppressing a decrease in the modeling accuracy of the three-dimensional structure due to the winding of the powders 20 and 20 ′ and an effect of improving the recyclability of the powder 20 can be obtained.

  The modeling method applicable in this embodiment is not limited to the binder jet method described above, and may be a laser sintering method (LS method or the like), an electron beam sintering method (EBM method or the like), or the like. That is, as a powder bonding means, a means for bonding powders using a liquid discharged from a liquid discharge head is used, but instead of this, powders are sintered using a laser irradiation means or the like. It is also possible to use means for coupling by ligation or the like. The present invention is applicable to any three-dimensional modeling method in which the powder layer 31 is formed and the powder in the powder layer is bonded.

  In the case of the binder jet system as in the present embodiment, it is common to form the layered structure 30 by using gypsum as the powder 20, discharging the binder ink from the inkjet head, and solidifying the gypsum powder. However, by using sand as the powder 20 and discharging the binder resin from the inkjet head, a three-dimensional structure used for a mold or the like can be formed. In the case of a binder jet method, metal, ceramic, glass, or the like can be used for the powder 20. In the binder jet method, the powder 20 coated with a material that can be dissolved in the binding liquid is used, and the binding liquid is discharged from the ink jet head so that the powders are bonded to each other via the coating material. 30 can also be formed.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
By moving a flattening member such as the flattening roller 12, the powder 20 stored in the supply tank 21 is transferred and supplied to the modeling tank 22, and the flattening process is performed to flatten the powder in the modeling tank. 3D modeling in which the layered structure is laminated by repeatedly performing the operation of combining the powder of the powder layer 31 formed in the modeling tank into a required shape to form the layered structure 30 A three-dimensional modeling apparatus for modeling an object, wherein a powder return member such as a flattening roller 12 is moved so as to return a movement path of the flattening member, and thereby the flattening member passes through the modeling tank. A surplus powder returning process for returning at least a part of the surplus powder 20 ′ transferred to the supply tank is performed.
In general, when a three-dimensional structure is formed by combining a powder of a powder layer formed in a modeling tank into a required shape to form a layered structure, a powder layer that is uniformized at a high powder density is formed. It is desirable to form. At this time, if the amount of powder transferred and supplied from the supply tank to the modeling tank is insufficient, the amount of powder is insufficient on the downstream side in the movement direction of the flattening member of the modeling tank, and is uniform throughout the modeling tank. A large amount of powder cannot be distributed, and the powder layer cannot be made uniform at a high powder density. Therefore, performing the flattening process so that the powder (surplus powder) transferred by the flattening member remains until it passes through the modeling tank forms a uniform powder layer at a high powder density. It becomes important for.
In this case, in order to recover the surplus powder transferred until it passes through the modeling tank, a surplus powder receiving tank for storing the surplus powder is provided as in the conventional case. Is required, which increases the size of the apparatus. In particular, the more surplus powder that remains during the flattening process, the more advantageous it is to form a uniform powder layer with a high powder density. In this case, a larger surplus powder receiving tank. Is required.
Also, if a configuration is adopted in which the surplus powder is temporarily recovered in the surplus powder receiving tank and the surplus powder is returned to the supply tank by the powder pump, the surplus powder receiving tank itself is removed. It is possible to reduce the size. However, in order to realize this configuration, a large space (transfer path for surplus powder) for arranging the powder pump from the surplus powder receiving tank to the supply tank is required, and the entire apparatus is increased in size. .
In this aspect, at least a part of the surplus powder transferred by the flattening member until it passes through the modeling tank is returned to the supply tank by the powder return member that moves so as to return the movement path of the flattening member. Can do. According to this, since the surplus powder can be returned to the supply tank using the movement path of the flattening member during the flattening process, a new transfer path is not required to return the surplus powder to the supply tank. The device can be downsized.

(Aspect B)
In the aspect A, at the time of the surplus powder returning process, the lowermost part of the powder returning member is maintained at a height equal to or lower than the powder surface of the modeling tank flattened during the flattening process. The body return member is moved.
According to this, surplus powder can be returned to the supply tank 21 substantially without using it for formation of the powder layer of a modeling tank.

(Aspect C)
In the aspect A or B, there is a powder holding member such as a powder holding table 81 for temporarily holding the surplus powder, and in the surplus powder returning process, the surplus held by the powder holding member At least a part of the powder is returned to the supply tank by the powder return member.
According to this, the surplus powder transferred by the flattening member until it passes through the modeling tank can be temporarily held, and the transition from the flattening process to the surplus powder returning process is facilitated.

(Aspect D)
In the aspect C, during the flattening process, the holding surface of the powder holding member on which the surplus powder is placed is moved to a position lower than the lowest part of the flattening member, and during the surplus powder returning process It is characterized by having holding surface driving means such as a motor 28 and a motor driving unit 514 for moving the holding surface to substantially the same position as the lowest part of the powder returning member.
According to this, the surplus powder can be appropriately transferred between the modeling tank and the powder holding member.

(Aspect E)
In the aspect D, there is a modeling stage driving unit such as a motor 28 and a motor driving unit 514 for moving the modeling stage 24 on which the powder in the modeling tank is placed up and down, and the holding surface driving unit is the modeling stage driving unit The holding surface is moved using a driving force of.
According to this, it is possible to realize a simpler configuration than that in which the holding surface driving unit is configured by a driving unit separate from the modeling stage driving unit, which is advantageous for downsizing the apparatus.

(Aspect F)
In the aspect E, a pre-powder layer 31 ′ that is flattened thicker than the target thickness Δt of the powder layer is formed during the flattening process, and the powder return member is formed during the surplus powder returning process. By moving, at least a part of the surplus powder is returned to the supply tank, and the powder in the modeling tank is flattened to form the powder layer 31 having a target thickness Δt. The modeling stage driving means moves the holding surface in conjunction with an operation of moving the modeling stage to a position higher than that during the flattening process during the surplus powder returning process.
According to this, in the configuration using the modeling stage driving means as the holding surface driving means, it is possible to realize appropriate interlocking.

(Aspect G)
In any one of the aspects A to E, the pre-powder layer 31 ′ that is flattened to be thicker than the target thickness Δt of the powder layer is formed during the flattening process, and during the surplus powder returning process The powder return member is moved to return at least a part of the excess powder to the supply tank, and the powder in the modeling tank is flattened to form the powder layer 31 having the target thickness Δt. It is characterized by that.
This is advantageous for forming a more uniform powder layer 31 having a high powder density.

(Aspect H)
In any one of the above aspects A to G, the same member is used as the flattening member and the powder returning member.
According to this, a simpler configuration can be realized than in the case where the flattening member and the powder returning member are configured as separate members, which is advantageous for downsizing of the apparatus.

(Aspect I)
In any one of the aspects A to H, at least one of the flattening member and the powder returning member is a rotating member such as the flattening roller 12, and a lower surface side of the rotating member is a moving direction of the rotating member. And is driven to rotate in the direction of surface movement in the same direction.
According to this, the frictional force between the peripheral surface of the rotating member and the powder is always a dynamic frictional force, and the smoothness of the surface of the powder layer can be improved.

(Aspect J)
By moving the flattening member, the powder stored in the supply tank is transferred and supplied to the modeling tank, and a flattening process for flattening the powder in the modeling tank is executed and formed in the modeling tank. A method of manufacturing a three-dimensional structure that forms a three-dimensional structure on which the layered structure is laminated by repeatedly performing an operation of forming a layered structure by combining the powder of the powder layer formed into a required shape The powder return member is moved so as to return the movement path of the flattening member, whereby at least a part of the surplus powder transferred by the flattening member until it passes through the modeling tank is supplied. A surplus powder returning process for returning to the tank is performed.
According to this, a three-dimensional structure with high modeling accuracy can be manufactured by forming a powder layer that is made uniform at a high powder density by a small three-dimensional modeling apparatus.

(Aspect K)
By moving the flattening member, the powder stored in the supply tank is transferred and supplied to the modeling tank, and a flattening process for flattening the powder in the modeling tank is executed and formed in the modeling tank. The three-dimensional modeling apparatus for modeling the three-dimensional structure formed by laminating the layered structure is repeatedly performed by combining the powder of the powder layer formed into a required shape to form a layered structure. A program for causing a computer of the three-dimensional modeling apparatus to function as control means, wherein the control means moves the powder return member so as to return the movement path of the flattening member, thereby flattening. A surplus powder returning process is performed in which at least a part of the surplus powder transferred by the member until it passes through the modeling tank is returned to the supply tank.
According to this, a three-dimensional structure with high modeling accuracy can be manufactured by forming a powder layer that is made uniform at a high powder density by a small three-dimensional modeling apparatus.
This program can be distributed or obtained in a state of being recorded on a recording medium such as a CD-ROM. It is also possible to distribute and obtain signals by placing this program and distributing or receiving signals transmitted by a predetermined transmission device via transmission media such as public telephone lines, dedicated lines, and other communication networks. Is possible. At the time of distribution, it is sufficient that at least a part of the computer program is transmitted in the transmission medium. That is, it is not necessary for all data constituting the computer program to exist on the transmission medium at one time. The signal carrying the program is a computer data signal embodied on a predetermined carrier wave including the computer program. Further, the transmission method for transmitting a computer program from a predetermined transmission device includes a case where data constituting the program is transmitted continuously and a case where it is transmitted intermittently.

DESCRIPTION OF SYMBOLS 1 Modeling part 5 Modeling unit 10 Modeling liquid 11 Powder tank 12 Flattening roller 20 Powder 20 'Surplus powder 21 Supply tank 22 Modeling tank 23 Supply stage 24a Stage rack 24b Stopper 24 Modeling stage 30 Layered structure 31 Powder layer 31 ′ Pre-powder layer 50 Liquid discharge unit 52 Head 80 Surplus powder receiving mechanism 81 Powder holding table 82 Support shaft 83 Slide member 500 Control unit 600 Modeling data creation device

JP 2017-7321 A

Claims (11)

By moving the flattening member, the powder stored in the supply tank is transferred and supplied to the modeling tank, and a flattening process for flattening the powder in the modeling tank is executed and formed in the modeling tank. A three-dimensional modeling apparatus for modeling a three-dimensional structure in which the layered structure is laminated by repeatedly performing an operation of forming a layered structure by combining the powder of the powder layer formed into a required shape ,
By moving the powder return member so as to return the movement path of the flattening member, the surplus powder that has been transferred by the flattening member until it passes through the modeling tank is returned to the supply tank. A three-dimensional modeling apparatus characterized by executing a powder returning process. The three-dimensional modeling apparatus according to claim 1,
During the surplus powder returning process, the powder returning member is moved while maintaining the lowest part of the powder returning member at a height equal to or lower than the powder surface of the modeling tank flattened during the flattening process. A three-dimensional modeling apparatus characterized in that In the three-dimensional modeling apparatus according to claim 1 or 2,
A powder holding member for temporarily holding the surplus powder;
In the surplus powder returning process, at least a part of the surplus powder held by the powder holding member is returned to the supply tank by the powder returning member. In the three-dimensional modeling apparatus according to claim 3,
At the time of the flattening process, the holding surface of the powder holding member on which the surplus powder is placed is moved to a position lower than the lowest part of the flattening member, and the powder return member at the time of the surplus powder returning process A three-dimensional modeling apparatus comprising holding surface driving means for moving the holding surface to substantially the same position as the lowermost part of the apparatus. The three-dimensional modeling apparatus according to claim 4,
Having a modeling stage driving means for vertically moving a modeling stage on which the powder in the modeling tank is placed;
The three-dimensional modeling apparatus, wherein the holding surface driving unit moves the holding surface using a driving force of the modeling stage driving unit. The three-dimensional modeling apparatus according to claim 5,
During the flattening treatment, a pre-powder layer that is flattened thicker than the target thickness of the powder layer is formed,
At the time of the surplus powder returning process, the powder returning member is moved so that at least a part of the surplus powder is returned to the supply tank and the powder in the modeling tank is flattened to obtain the target thickness of the powder. Forming a body layer,
The holding surface driving unit moves the holding surface in conjunction with an operation in which the modeling stage driving unit moves the modeling stage to a position higher than that during the flattening process during the surplus powder returning process. Characteristic 3D modeling equipment. In the three-dimensional modeling apparatus according to any one of claims 1 to 5,
During the flattening treatment, a pre-powder layer that is flattened thicker than the target thickness of the powder layer is formed,
At the time of the surplus powder returning process, the powder returning member is moved so that at least a part of the surplus powder is returned to the supply tank and the powder in the modeling tank is flattened to obtain the target thickness of the powder. A three-dimensional modeling apparatus characterized by forming a body layer. The three-dimensional modeling apparatus according to any one of claims 1 to 7,
The three-dimensional modeling apparatus using the same member as the planarizing member and the powder returning member. The three-dimensional modeling apparatus according to any one of claims 1 to 8,
At least one of the flattening member and the powder returning member is a rotating member, and the lower surface side of the rotating member is rotationally driven in a direction in which the surface moves in the same direction as the moving direction of the rotating member. 3D modeling equipment. By moving the flattening member, the powder stored in the supply tank is transferred and supplied to the modeling tank, and a flattening process for flattening the powder in the modeling tank is executed and formed in the modeling tank. A method of manufacturing a three-dimensional structure that forms a three-dimensional structure on which the layered structure is laminated by repeatedly performing an operation of forming a layered structure by combining the powder of the powder layer formed into a required shape Because
By moving the powder return member so as to return the movement path of the flattening member, the surplus powder that has been transferred by the flattening member until it passes through the modeling tank is returned to the supply tank. A method for producing a three-dimensional structure, comprising performing a powder returning process. By moving the flattening member, the powder stored in the supply tank is transferred and supplied to the modeling tank, and a flattening process for flattening the powder in the modeling tank is executed and formed in the modeling tank. The three-dimensional modeling apparatus for modeling the three-dimensional structure formed by laminating the layered structure is repeatedly performed by combining the powder of the powder layer formed into a required shape to form a layered structure. As a control means, a program for causing the computer of the three-dimensional modeling apparatus to function,
The control means moves at least a part of the surplus powder transferred by the flattening member until it passes through the modeling tank by moving the powder returning member so as to return the moving path of the flattening member. A program for executing a surplus powder returning process for returning to a supply tank.

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