JP2016093909A - Three-dimensional molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dropping of powder on a flattened region and to prevent degradation in accuracy of a molded product.SOLUTION: A mechanism to vertically move flattening means is provided so as to separate the flattening means (a rotary roller 12 and a powder removal plate 13) from a powder tank 11. After a powder material 20 is flattened by the rotary roller 12, the flattening means is elevated prior to an original point return step, and then the original point return step is carried out. By elevating the flattening means, a distance to the flattened powder surface or a powder surface depositing or adhering to a frame of the powder tank 11 increases, which can prevent the powder from dropping onto the flattened region during horizontal movement to return to the original point.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a three-dimensional modeling apparatus that models a three-dimensional model.

  Three-dimensional modeling to produce a predetermined three-dimensional structure by laminating each layer with a modeling liquid on metal or non-metal powder loaded on a vertically movable table (stage) In the apparatus, a technique for forming a flat layer of powder using a roller that rotates in the opposite direction to the moving direction (reverse rotation) is already known.

  In the conventional three-dimensional modeling apparatus, as schematically shown in FIG. 7, the powder 20 is spread as a layer having a predetermined thickness with a rotating roller 12 or blade (after a flat layer is formed), and then rotated. When the roller or blade returns to the origin position, the powder adhering to the frame portion of the powder tank 11 is transferred to the rotating roller or blade, and the transferred powder is spread out (flattened area). ), The flatness accuracy is deteriorated and the accuracy of the shaped product is lowered.

  Japanese Patent No. 5408151 (Patent Document 1) discloses a powder removing plate for removing powder adhering to a roller for the purpose of preventing scattering of the powder adhering to the roller to an area where the powder surface is flattened by the roller. Is provided so as to be in contact with the roller at a position in the powder non-planarized region and below the roller rotation center.

  However, even in the configuration described in Patent Document 1, when the rotating roller or blade returns to the origin position after the powder is spread as a layer having a predetermined thickness by the rotating roller or blade, the frame portion of the powder tank is used. The problem is that the powder adhering to the roller is transferred to a rotating roller or blade, and the transferred powder falls to the flattened area, which deteriorates the flatness accuracy and lowers the accuracy of the shaped product. Not done.

  This invention is made | formed in view of said subject in a three-dimensional modeling apparatus, and it aims at preventing the powder fall to the planarized area | region and preventing the precision reduction of a modeling product.

  In order to solve the above-mentioned problems, the present invention is a three-dimensional modeling apparatus that forms a three-dimensional model by dropping a modeling liquid onto a powder, and a tank for holding and laminating powders; A flattening means for flattening the powder by moving the flattening unit, and when the flattening unit returns to the origin after the movement, the distance between the tank and the flattening means is the same as that during the movement. A separation mechanism for separating the flattening means and the tank from each other is provided so as to be larger than the distance between the tank and the flattening means.

  In order to solve the above problems, the present invention is a three-dimensional modeling apparatus that forms a three-dimensional structure by dropping a modeling liquid onto a powder, and a tank for holding and laminating powder And a flattening means for flattening the powder by moving the flattening unit, and the upper end of the tank frame on the downstream side in the moving direction of the flattening unit during the powder flattening of the tank is inclined. It is provided as a surface.

  According to the three-dimensional modeling apparatus of the present invention, when the flattening unit returns to the original position after the powder flattening, the powder to the flattening means on the upstream side (downstream side during flattening) that passes through the flattened region. Since the body transfer can be prevented, the powder can be prevented from falling to the flattened region, so that the accuracy of the shaped product can be prevented from being lowered.

1 is an external perspective view showing an example of a three-dimensional modeling apparatus according to the present invention. It is a schematic diagram explaining the flow of modeling in a three-dimensional modeling apparatus. It is a schematic diagram explaining the feature of 1st Embodiment of invention. It is a schematic diagram explaining the feature of 2nd Embodiment of invention. It is a schematic diagram explaining the feature of 3rd Embodiment of invention. It is a schematic diagram explaining the feature of 4th Embodiment of invention. It is a schematic diagram explaining the problem in a three-dimensional modeling apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an external perspective view showing an example of a three-dimensional modeling apparatus according to the present invention. FIG. 2 is a schematic diagram for explaining the flow of modeling in the three-dimensional modeling apparatus.

  The three-dimensional modeling apparatus (three-dimensional modeling apparatus) shown in FIG. 1 is a modeling unit 1 on which a modeling layer to which powder is combined is formed, and a modeling unit that models a three-dimensional model by discharging a modeling liquid to the modeling unit 1. And 5. In addition, a powder supply unit (not shown) is also provided.

  The modeling unit 1 includes a powder tank 11 for holding and laminating powder, a flattening roller 12 as a flattening means, and the like. The modeling unit 5 includes a discharge head unit 51 and a head cleaning mechanism.

  The powder tank 11 has a tank shape or box shape including a supply tank 21 and a modeling tank 22, and stages (tables) 23 and 24 on the bottom surface thereof are vertically movable. The supply tank 21 and the modeling tank 22 are provided adjacent to each other, and a three-dimensional modeled object is modeled on the stage 24 of the modeling tank 22.

  The stage 23 of the supply tank 21 is raised (raised), and the powder material filled in the supply tank 21 is supplied onto the stage 23 of the supply tank using the flattening roller 12. The flattening roller 12 flattens the upper surface of the powder material loaded on the stage of the supply tank 21 and the modeling tank 22 to form a powder layer.

  The modeling liquid is discharged onto the powder layer 20 formed on the stage 24 using the head 51a. The head cleaning mechanism adheres to the head 51a and sucks the modeling liquid, and wipes the discharge port.

  The powder tank 11 has a box shape, and is provided with two tanks of which the upper surface of the supply tank 21 and the modeling tank 22 is opened. Stages 23 and 24 are held inside the supply tank 21 and the modeling tank 22 so as to be movable up and down. The side surface of each stage is arranged in contact with the frame of each tank, and the upper surface of the stage is kept horizontal.

  Around the powder tank 11, a powder drop opening (not shown) having a concave shape with an open upper surface is provided. When the powder layer is formed, surplus powder accumulated by the flattening roller 12 falls on the powder dropping port. The surplus powder that has fallen into the powder dropping port is returned to a powder supply unit (not shown) located above the supply tank 21 by an operator or a suction mechanism.

  A powder supply unit (not shown) has a tank shape and is disposed above the supply tank 21. When the molding operation is in an initial stage or when the amount of powder in the supply tank decreases, the powder in the tank is supplied to the supply tank. 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 has a function of transporting powder from the supply tank 21 to the modeling tank 22 and forming a powder layer having a predetermined thickness (for example, thickness Δt). As shown in FIG. 1, the flattening roller 12 is a bar material that is longer than the internal dimensions of the modeling tank 22 and the supply tank 21 (that is, the width of the “part where powder is supplied or charged”). Yes, both ends are supported by the reciprocating device 25.

  The flattening roller 12 moves horizontally so as to pass above the supply tank 21 and the modeling tank 22 from the outside of the supply tank 21 while rotating, thereby supplying the powder onto the modeling tank. Specifically, the stage 23 of the supply tank 21 is raised and the stage 24 of the modeling tank 22 is lowered. At this time, the lowering distance of the stage 23 is set so that the distance between the uppermost powder layer of the modeling tank 22 and the lower portion (downward tangent portion) of the flattening roller becomes Δt. In the present embodiment, Δt is preferably about 50 to 300 μm, for example, about 100 μm.

  Next, the powder 20 positioned above the upper surface level of the supply tank 21 is supplied to the modeling tank 22 by rotating and moving the flattening roller 12, and a predetermined thickness is provided on the stage 24 of the modeling tank 22. A powder layer of Δt is formed.

  Here, the flattening roller 12 can move while maintaining a constant distance from the upper surface level of the modeling tank 22 and the supply tank 21. As a result of being able to move while being kept constant, a powder layer having a uniform thickness is formed on the modeling tank or on the already formed modeling layer 30 while conveying the powder onto the modeling tank 22 by the flattening roller 12. Can be formed. The flattening roller 12 is preferably rotated (reversely rotated) in the counter direction with respect to the direction of horizontal movement in order to convey powder.

  Further, the flattening roller 12 is provided with a powder removing plate 13 for removing the adhered powder. The powder removing plate 13 is provided so as to be in contact with the roller in the powder non-planarized region and at a position below the roller rotation center in order to prevent the powder adhering to the roller from scattering to the flattened region. Is desirable.

  The flattening member can be not only a roller but also a square blade. Depending on the characteristics of the powder (for example, the degree of particle condensation and fluidity) and the storage state of the powder (for example, storage in a high humidity environment), the selection of the planarizing member and the driving conditions can be changed.

  The discharge head unit 51 includes a cyan head, a magenta head, a yellow head, a black head, and a clear head. Inside the three-dimensional modeling apparatus, a plurality of tanks containing each of a cyan modeling liquid, a magenta modeling liquid, a yellow modeling liquid, a black modeling liquid, and a clear modeling liquid are mounted. Each color head included in the head unit is connected to a tank containing a modeling liquid of a corresponding color by a flexible tube (not shown). The head 51a discharges the modeling liquid of each color to the powder layer by control.

  The number of heads and the type of modeling liquid to be discharged can be changed. For example, in the case where coloring is not required for the modeled object, only the clear head may be set and only the clear modeling liquid may be discharged.

  The discharge head unit 51 can move in the Y-axis direction (the arrow Y direction in FIG. 1) and the Z-axis direction (the vertical direction in FIGS. 1 and 2) using the guide rail. When the surface of the supply tank and the modeling tank (surface of the powder layer 20) is flattened and densified by the flattening roller, the head 51a can be retreated to a position where it does not interfere.

  When the modeling liquid discharged by the head 51a is mixed with the powder 20, the adhesive contained in the powder is dissolved, and the dissolved adhesives are bonded to each other. As a result, a modeling layer having a thickness Δt is formed.

  Next, a new modeling layer is formed by repeating the above-described powder supply / planarization process, densification process, and modeling liquid discharge process by the head. At this time, the new modeling layer and the lower modeling layer are integrated to form a part of the three-dimensional modeled object. Thereafter, the powder supply / flattening process, the densification process, and the modeling liquid discharge process by the head are repeated as many times as necessary to complete the three-dimensional shaped object.

  The head cleaning mechanism is mainly composed of a cap and a wiper blade. The cap is brought into close contact with the nozzle surface of the head 51a, 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 nozzle surface is wiped (wiped) to form a meniscus for the nozzle (the inside of the nozzle is in a negative pressure state). Further, the head cleaning mechanism covers the nozzle surface of the head when the modeling liquid is not discharged, and prevents powder from mixing into the nozzle and drying of the modeling liquid.

  The powder used in the three-dimensional modeling apparatus of the present invention may be metal powder, ceramic powder, or glass powder. Depending on the particle size of the powder to be used and the required accuracy, the thickness of the powder layer, the driving condition of the flattening means, and the high density driving condition can be appropriately changed.

  Next, features of the first embodiment of the invention will be described with reference to FIG. In the first embodiment, a mechanism is provided that allows the flattening means to move up and down (up and down) so that the flattening means can be separated from the powder tank. In the present embodiment, as the planarization means, the planarization roller 12 is used, and the planarization unit including the planarization roller 12 and the powder removing plate 13 can be moved up and down. However, a blade can also be used as the flattening means as described above.

  As shown in FIG. 3, after the powder 20 is flattened by the flattening unit (the rotating roller 12 and the powder removing plate 13) (after movement for flattening), the flattening unit is placed before the return to origin process. Perform the home-return process after raising. By raising the flattening unit, the distance between the flattened powder surface and the powder surface adhering to and depositing on the frame of the powder tank is increased, so that the powder is flattened while moving horizontally by returning to the origin. It is possible to prevent adhesion and transfer to the unit (tangent portion of the rotating roller, blade edge, bottom surface portion). Therefore, since the powder fall to the planarized area can be prevented, it is possible to prevent the accuracy of the shaped product from being lowered.

Note that it is desirable that the planarization unit rising distance (Δt1) is short in order to improve productivity. For example, 1 mm. Moreover, productivity can be improved by implementing planarization unit raise at the timing which the planarization unit passed the tank frame (frame of the powder tank 11) of the planarization downstream part in the planarization process.
After the flattening unit returns to the origin, the flattening unit lowering step is performed. The descending distance is the same value as the ascending distance (Δt1).

  Next, the features of the second embodiment of the invention will be described with reference to FIG. The second embodiment is a configuration in which a mechanism capable of moving the entire powder tank up and down (raising and lowering) is provided so that the powder tank 11 can be separated from the flattening means. In addition, the description which overlaps with the said 1st Embodiment is abbreviate | omitted.

  After the powder 20 is flattened by the flattening unit (the flattening roller 12 and the powder removing plate 13) (after movement for flattening), the powder tank 11 is moved from the imaginary line to the solid line before the origin returning step. The origin return process is carried out after being lowered. Similar to the effect of the first embodiment, by lowering the powder vessel 11, the distance from the flattened powder surface and the powder surface adhering and depositing on the frame portion of the powder vessel is increased. During the movement, the powder can be prevented from adhering and transferring to the flattening unit (tangent part of the rotating roller, blade edge, bottom face part). Therefore, since the powder fall to the planarized area can be prevented, it is possible to prevent the accuracy of the shaped product from being lowered.

  In addition, it is desirable that the powder tank descending distance (Δt2) is short in order to improve productivity. For example, 1 mm. Further, as with the flattening unit rising in the first embodiment, the powder tank 11 descends at the timing when the flattening unit passes the tank frame (the frame of the powder tank 11) in the flattening downstream portion in the flattening step. By implementing, productivity can be improved.

  After the flattening unit returns to the origin, a powder bath raising process is performed. The rising distance is the same value as the falling distance (Δt2). Note that a blade may be used as the flattening means.

  Next, features of the third embodiment of the invention will be described with reference to FIG. In the third embodiment, a mechanism is provided in which only the powder tank wall (tank frame) 11D on the downstream side of the flattening (downstream side in the moving direction of the flattening unit = right side in the drawing) 11D can be lifted (raised and lowered). is there. In addition, the description which overlaps with the said 2nd Embodiment is abbreviate | omitted.

  After the powder 20 is flattened by the flattening unit (the flattening roller 12 and the powder removing plate 13), the stages 23 and 24 of the supply tank and the modeling tank and the powder tank wall 11D are lowered, and then the flattening unit. Is the process sequence for returning to the origin. Similar to the effect of the second embodiment, by lowering the stages 23 and 24 and the powder vessel wall 11D, the distance from the flattened powder surface and the powder surface adhering and depositing on the vessel frame is increased, so that the origin is restored. It is possible to prevent the powder from adhering to and transferring to the flattening unit (tangent part of the rotating roller, blade edge, bottom face part) during horizontal movement. Therefore, since the powder fall to the flattened area can be prevented, the accuracy of the shaped product can be prevented from being lowered.

  Furthermore, compared to the second embodiment in which the entire powder tank is moved up and down, only the tank wall 11D on the downstream side of the flattening of the powder tank is moved up and down, so that less torque is required. Can be obtained.

In addition, it is desirable that the descending distance (Δt3) of the powder vessel wall 11D is short in order to improve productivity. For example, 1 mm. Similarly to the second embodiment, the lowering of the stages 23 and 24 and the powder tank wall 11D is performed at the timing when the flattening unit passes the tank frame 11D on the downstream side of the flattening in the flattening step. Can be improved.
After the flattening unit returns to the origin, the ascending process of the stages 23 and 24 and the powder vessel wall 11D is performed. The rising distance is the same value as the falling distance (Δt3).

  Next, the features of the fourth embodiment of the invention will be described with reference to FIG. The fourth embodiment has a configuration in which the upper end portion of the powder tank wall 11 on the flattening downstream side (right side in the drawing) is provided as the inclined surface 11E. In addition, the description which overlaps with said each embodiment is abbreviate | omitted.

  In the fourth embodiment, the inclined surface 11E provided at the upper end portion of the powder tank wall 11 on the downstream side of the flattening (right side in the drawing) descends from the modeling tank 22 side toward the outside of the tank frame on the downstream side of the flattening. The shape of the direction. In addition, it is desirable to provide a vibrator 29 (vibrating means) directly inside the tank frame of the inclined surface 11E. The vibrator 29 can be vibrated by driving means (not shown).

  By providing the inclined surface 11E on the upper surface of the tank frame portion on the downstream side of the flattening, the powder 20 is flattened by the flattening unit (the flattening roller 12 and the powder removing plate 13), and then the powder is transferred to the tank frame portion ( It falls from the inclined surface 11E). By dropping the powder from the tank frame, it is possible to prevent the powder from adhering and transferring to the flattening unit when the flattening unit returns to the origin, and to prevent the powder from dropping to the flattened area. . For this reason, the effect which prevents the precision fall of a modeling product can be acquired.

In addition, a powder fall effect can be acquired, so that the inclination angle of the inclined surface 11E is steeper, for example, 45 degrees or more is desirable.
In addition, by activating (vibrating) the vibrator 29 provided immediately below the tank frame (near the upper end of the tank frame) of the inclined surface 11E, the tank frame unit is vibrated and the tank frame unit (inclined surface 11E). The powder adhering to and depositing on can be more reliably dropped.

  Further, by performing a surface treatment for improving the sliding of the powder on the surface of the inclined surface 11E, a further powder dropping effect can be obtained. By carrying out powder fall reliably, the distance between the powder surface adhering and depositing on the layer frame and the flattening unit is increased, so that the powder fall prevention effect to the flattened area can be obtained more reliably. Can do.

The configuration of this embodiment can also be applied to the first to third embodiments described above (including a separation mechanism that separates the flattening means and the powder tank), and in that case, more reliably. An effect of preventing the powder from dropping into the flattened region can be obtained.
In the configuration in which only the powder tank frame on the downstream side of the flattening is raised and lowered as in the third embodiment, the vibrator may be provided in a separate tank frame.

  As mentioned above, although this invention was demonstrated by embodiment of illustration, this invention is not limited to this, It can change suitably.

DESCRIPTION OF SYMBOLS 1 Modeling part 5 Modeling unit 11 Powder tank 12 Flattening roller 13 Powder removal board 20 Powder layer 21 Supply tank 22 Modeling tank 23 Supply tank stage 24 Modeling tank stage 29 Vibrator (vibration means)
30 Modeling layer 51 Discharge head unit 51a Head

Japanese Patent No. 5408151

Claims (7)

A three-dimensional modeling apparatus that forms a three-dimensional structure by dropping a modeling liquid on the powder,
A tank for holding and laminating powder;
A flattening means for flattening the powder by moving the flattening unit;
When the flattening unit returns to the origin after the movement, the flattening is performed such that the distance between the tank and the flattening means is larger than the distance between the tank and the flattening means during the movement. A three-dimensional modeling apparatus comprising a separation mechanism for separating means and the tank.   The three-dimensional modeling apparatus according to claim 1, wherein the separation mechanism is configured such that the flattening unit can be separated from the tank.   The three-dimensional modeling apparatus according to claim 1, wherein the separation mechanism is configured such that the tank can be separated from the flattening unit.   2. The structure according to claim 1, wherein the separation mechanism is configured such that a tank frame on the downstream side in the moving direction of the flattening unit when the flattening unit powder is flattened can be separated from the flattening unit. The three-dimensional modeling apparatus described.   The upper end part of the tank frame of the said tank of the movement direction at the time of the powder flattening of the said flattening unit is provided as an inclined surface as described in any one of Claims 1-4 characterized by the above-mentioned. 3D modeling equipment. A three-dimensional modeling apparatus that forms a three-dimensional structure by dropping a modeling liquid on the powder,
A tank for holding and laminating powder;
A flattening means for flattening the powder by moving the flattening unit;
The three-dimensional modeling apparatus, wherein an upper end portion of the tank frame on the downstream side in the movement direction of the tank during powder flattening of the tank is provided as an inclined surface. The three-dimensional modeling apparatus according to claim 5, further comprising a vibrating unit that vibrates the vicinity of the upper end portion of the tank frame provided as the inclined surface.

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