JP2017001213A - Apparatus for forming three dimensional body, method for forming three dimensional body, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which prevents an accuracy of a formed article from lowering on account of varying a filling state of a powder layer due to environmental changes when molding using powder.SOLUTION: The liquid volume of a forming liquid discharged by a liquid-discharging head 52 is controlled by a liquid-discharging head 52 for discharging liquid, a forming tank 22 in which a forming layer 30 is formed, a powder weight-detecting tank 122 capable of forming a powder layer 131 for detecting a weight by the same thickness as that of a powder layer 31 by supplying a powder 20 when forming the powder layer 31 by supplying the powder 20 into the forming tank 22, a weight sensor for detecting a weight of the powder 20 on a weight-detecting stage 124 of the powder weight-detecting tank 122, and a weight of the powder layer 31 for detecting a weight obtained from a detecting result of the weight sensor.SELECTED DRAWING: Figure 15

Description

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

  As a three-dimensional modeling apparatus (three-dimensional modeling apparatus) for modeling a three-dimensional modeled object (three-dimensional modeled object), for example, one that models by a layered modeling method is known. For example, a flattened metal or non-metallic powder is formed in a layer shape on a modeling stage (this is referred to as a “powder layer”), and a modeling liquid is discharged onto the powder layer to form a powder. Layering a modeling layer by forming a layered modeling object (which is referred to as a “modeling layer”) to which the bodies are combined, forming a powder layer on the modeling layer, and forming the modeling layer again. 3D modeling of the three-dimensional model.

  Conventionally, in order to prevent a pattern from being formed on the surface by not applying the roller part to the surface and the part that affects the surface of the modeled object, the liquid is not discharged or the hollow part is reduced by reducing the discharge amount. What is provided with the hollow part production | generation means to produce | generate is known (patent document 1).

JP 2013-067118 A

  By the way, when performing powder layered modeling using powder (powder layered modeling), there is a problem that the filling state of the powder layer is changed due to environmental changes, and the accuracy of the modeled product is lowered.

  This invention is made | formed in view of said subject, and it aims at improving the precision of a three-dimensional molded item.

In order to solve the above problems, the three-dimensional modeling apparatus according to the present invention is:
A three-dimensional modeling apparatus that discharges liquid to a powder layer, forms a layered structure that combines the powders of the powder layer, and forms a three-dimensional structure by stacking the layered structure,
Liquid ejection means for ejecting the liquid;
A modeling tank in which the layered model is formed,
Powder weight detection capable of supplying the powder and forming a powder layer for weight detection with the same thickness as the powder layer when the powder is supplied to the modeling tank to form the powder layer A tank,
Weight detection means for detecting the weight of the powder layer for weight detection in the powder weight detection tank;
And a means for controlling the drop volume of the modeling liquid discharged by the liquid discharge means from the detection result of the weight detection means.

  According to the present invention, the accuracy of the three-dimensional structure is improved.

It is typical explanatory drawing with which it uses for description of the outline | summary of the three-dimensional modeling operation | movement in a three-dimensional modeling apparatus. It is a perspective explanatory view of a powder weight detection tank and a modeling tank part of a solid modeling device in a 1st embodiment of the present invention. It is a cross-sectional explanatory drawing similarly. It is typical sectional explanatory drawing with which it uses for description of modeling operation | movement in the embodiment. It is explanatory drawing of the lamination | stacking process of the powder layer for weight detection in the powder weight detection tank with which it uses for description of an example of filling rate calculation in the same embodiment. It is explanatory drawing of an example of the relationship between the number of lamination | stacking and powder total weight similarly. It is explanatory drawing of an example of the relationship between a weight difference (weight change difference) and a filling rate similarly. It is explanatory drawing of the filling state with which it uses for description of the determination of the drop volume of the modeling liquid according to a powder filling rate. It is explanatory drawing of an example of the relationship between a powder filling rate and drop volume similarly. It is explanatory drawing explaining an example of the relationship between the powder filling rate, the thickness of a powder layer, and drop volume with which it uses for description of the control method of the drop volume of modeling liquid. It is a block explanatory drawing with which the outline | summary of the whole structure of the embodiment is provided. It is a flowchart with which it uses for description of the process from modeling start to modeling completion | finish similarly. It is a schematic plane explanatory drawing of the three-dimensional modeling apparatus in 2nd Embodiment of this invention. It is a schematic side surface explanatory drawing similarly. It is a section explanatory view of a modeling part similarly. It is a block diagram with which it uses for description of the outline | summary of a control part similarly.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the outline of the three-dimensional modeling operation in the three-dimensional modeling apparatus will be described with reference to FIG. FIG. 1 is a schematic explanatory view for explaining the same.

  This three-dimensional modeling apparatus is a powder additive manufacturing apparatus, in which a three-dimensional object is formed by laminating a modeling layer 30 that is a layered object to which the powder 20 is bonded, and a three-dimensional object is formed in layers. And a liquid discharge head 52 which is a liquid discharge means for forming a three-dimensional structure by discharging the modeling liquid 10 onto the powder layer 31 which is a powder spread on the surface.

  The bottom of the modeling tank 22 can be moved up and down in the vertical direction (height direction) as the modeling stage 24. A three-dimensional modeled object in which the modeling layers 30 are sequentially stacked on the modeling stage 24 is modeled.

  Further, a flattening roller 12 for flattening the powder 20 supplied to the modeling tank 22 to form a powder layer 31 is provided. When the powder layer 31 is formed, the flattening roller 12 is moved in the arrow y2 direction while rotating in the arrow direction.

  A modeling operation by the three-dimensional modeling apparatus will be described. First, it is assumed that the modeling layer 30 is formed by discharging the modeling liquid 10 from the liquid discharge head 52 as shown in FIG.

  From this state, as shown in FIG. 1B, the modeling stage 24 is lowered by a predetermined amount (for the thickness Δt1 of the powder layer 31) in the direction of arrow z2 (downward). Then, the powder 20 is supplied onto the uppermost modeling layer 30 and the surface is flattened by the flattening roller 12 to form the powder layer 31. The thickness Δt1 of the powder layer 31 is about several tens of μm to 100 μm.

  The powder 20 may be supplied to the modeling tank 22 by having a supply tank and flattening while supplying from the supply tank by the flattening roller 12. Further, in the configuration having no supply tank as shown in FIG. 1, the powder 20 is supplied from the modeling tank 22 and is flattened by the flattening roller 12.

  Thereafter, as shown in FIG. 1C, the modeling liquid 10 is discharged by the liquid discharge head 52 to form the modeling layer 30 having a predetermined planar shape on the powder layer 31. The liquid discharge head 52 is driven and controlled according to the slice data of the target modeled object and discharges the droplet of the modeling liquid 10.

  By repeating the above operation, the modeling layer 30 is stacked to model a three-dimensional model.

  Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a perspective explanatory view of a powder weight detection tank and a modeling tank portion in the same embodiment, and FIG. 3 is a cross-sectional explanatory view. In the following, the axial direction of the flattening roller is defined as the width direction.

  In the direction of movement when the flattening roller 12 is flattened, a powder weight detection tank 122 is disposed upstream of the modeling tank 22. In the powder weight detection tank 122, a weight detection stage 124 to which the powder 20 is supplied is disposed so as to be movable up and down. The weight detection stage 124 and the modeling stage 24 are lifted and lowered by separate lifting mechanisms.

  On the weight detection stage 124, a weight sensor for detecting the weight of the placed powder 20 is disposed.

  Here, the weight detection stage 124 can be lowered every time the powder layer 31 is formed in the modeling tank 22 to form a weight detection powder layer 131 described later, or two or more layers of the powder layer 31. The weight detection powder layer 131 can be formed every time the number of layers (the number of times the powder layer 31 is formed) is lowered, for example, every five layers. One moving distance (falling distance) is the same as the moving distance of the modeling stage 24, that is, the thickness (lamination thickness) Δt1 of the powder layer 31 at the time of modeling. Thus, the weight detection powder layer 131 can be formed in the powder weight detection tank 122.

  In addition, the initial position of the weight detection stage 124 of the powder weight detection tank 122 is always performed before the modeling is started. The initial position is the same height as the edge of the modeling tank 22. Further, when modeling of the first layer is started, the layer is always moved downward by the stacking thickness.

  Further, the modeling tank 22 and the powder weight detection tank 122 have the same width in the direction orthogonal to the moving direction of the flattening roller 12 which is a flattening means for leveling the supplied powder 20. By having the same width, it is possible to prevent the supply amount of the powder 20 from changing.

  Next, the modeling operation in the present embodiment will be described with reference to FIG. FIG. 4 is a schematic cross-sectional explanatory view for explaining the same.

  First, as shown in FIG. 4A, the modeling tank 22 is in a state where the modeling liquid 10 is discharged from the liquid discharge head 52 and the modeling layer 30 is laminated, and the weight of the powder weight detection tank 122. It is assumed that the powder 20 is also supplied to the detection stage 124.

  From this state, when the n-th modeling layer 30 is formed, the weight detection stage 124 and the modeling stage 24 are lowered in the direction of the arrow z2 by the same distance (the thickness Δt1 of the powder layer 31).

  Then, as shown in FIGS. 4A and 4B, the supplied powder 20 is flattened while being transferred in the order of the powder weight detection tank 122 and the modeling tank 22 by the flattening roller 12.

  As a result, as shown in FIG. 3B, a powder layer 31 is formed in the modeling tank 22, and a layer of the powder 20 (also referred to as “weight detection powder”) is also formed in the powder weight detection tank 122. Layer 131 ").

  At this time, since the weight detection stage 124 and the modeling stage 24 are lowered by the same distance, a weight detection powder layer 131 in which the powder 20 is layered is formed in the powder weight detection tank 122. The filling rate of the powder layer for detection 131 is the same (including substantially the same) as the powder layer 31 formed in the modeling tank 22.

  Here, the filling rate of the powder layer 131 for weight detection is calculated from the weight difference between the (n−1) th layer and the nth layer. That is, the total weight of the powder 20 loaded on the weight detection stage 124 before the n-th powder layer 31 is formed and the weight detection after the n-th powder layer 31 is formed. The difference from the total weight of the powder 20 loaded on the stage 124 becomes the weight of the weight detection powder layer 131 of the nth layer, and the filling rate of the powder layer 31 of the nth layer of the modeling tank 22 Correlate with

  As described above, since the filling rate is the same as that of the weight detection powder layer 131 and the powder layer 31, the filling rate of the powder layer 31 is detected by detecting the weight of the weight detection powder layer 131. Can be obtained.

  Therefore, the weight of the powder layer 131 for weight detection, that is, the droplet volume (droplet volume, discharge amount, liquid amount, etc.) of the modeling liquid 10 discharged from the liquid discharge head 52 in accordance with the filling rate of the powder layer 31 is also referred to. .) Is re-determined, and from the (n + 1) th layer, control is performed to eject the droplet of the modeling liquid 10 with the re-determined droplet volume.

  In this way, the filling rate of the powder layer 31 is calculated from the weight of the weight detection powder layer 131 formed in the powder weight detection tank 122, and the droplet volume of the modeling liquid 10 is controlled from the obtained result. Perform modeling.

  Thereby, even if the filling state of the powder layer in the modeling tank changes due to environmental changes, the modeling liquid can be discharged with an excessive or insufficient inner droplet volume (discharge amount), and the accuracy of the modeled object is improved.

  Next, an example of filling rate calculation in the present embodiment will be described with reference to FIGS. FIG. 5 is an explanatory diagram of the lamination process of the weight detection powder layer in the powder weight detection tank, FIG. 6 is an explanatory diagram of an example of the relationship between the number of layers and the total powder weight, and FIG. 7 is the weight difference (weight change difference). It is explanatory drawing of an example of the relationship between a filling rate.

  For example, when the powder layer 31 is controlled to a discharge amount corresponding to the filling rate every time k layers (k = 1, 2,...) Are formed, the weight detection stage 124 is configured to generate powder when the knth layer is formed. It descends by the thickness of the layer 31.

  For example, as shown in FIG. 5A, from the state where the powder layer 31 is formed up to the n-th layer, the second n-th layer, the first n-th layer are sequentially formed as shown in FIGS. 5B and 5C. When the 3n-th powder layer 31 is stacked, weight detection powder layers 131 a and 131 b corresponding to the thickness of the powder layer 31 are sequentially stacked in the powder weight detection tank 122.

  The weight detection stage 124 is provided with a weight sensor, and detects (detects) the total weight of the powder 20 placed on the weight detection stage 124. Therefore, the weights of the weight detection powder layers 131 a and 131 b to be stacked can be calculated as a weight difference before and after the powder layer 31 is stacked.

  Here, when the second n-th powder layer 31 is formed, the weight in a state where the n-th layer is formed immediately before supplying the powder 20 is detected, and the second n-th powder layer 31 is formed. The weight immediately after formation is detected, and the difference is set as the weight of the weight detection powder layer 131 corresponding to the second nth layer.

  That is, since the moisture content of the powder changes due to long-time exposure to air, the weight per particle of the powder may change when the weights of the n-th layer and the second n-layer are measured. . Therefore, the difference between the weight after forming the n-th powder layer 31 and the weight after forming the second n-th powder layer 31 is the second n-th weight detection powder layer 131. If so, there is a possibility that an accurate weight (difference) cannot be obtained.

  In this way, for example, as shown in FIG. 6, the weight differences Δg1, Δg2, and Δg3 in the powder weight detection tank 122 before and after forming the n-th layer, the second n-layer, and the third n-layer powder layer 31 are obtained. .

  Therefore, as shown in FIG. 7, powder filling rates p1, p2, and p3 corresponding to the weight differences Δg1, Δg2, and Δg3 that are known in advance are obtained.

  Next, determination of the drop volume of the modeling liquid according to the powder filling rate will be described with reference to FIGS. FIG. 8 is an explanatory diagram of the filling state, and FIG. 9 is an explanatory diagram of an example of the relationship between the powder filling rate and the droplet volume.

  In powder layered modeling, the modeling layer 30 is formed by selectively discharging the modeling liquid 10 to the laminated powder layer 31 in accordance with slice data of a desired modeled object. At this time, as shown in FIGS. 8A and 8B, at least one drop of the modeling liquid 10 is discharged into a unit volume determined by the resolution of the image and the thickness Δt <b> 1 of the powder layer 31.

  Here, the droplet volume of the modeling liquid 10 to be discharged is included in a unit volume including the powder 20 which is an aggregate of powder, particles and the like (simply collectively referred to as “particles” and expressed as particles 20 a). A droplet volume sufficient to fill the volume of the void 300 (void volume) is required. Accordingly, the droplet volume of the modeling liquid 10 necessary for modeling is determined from the resolution of the image, the thickness (lamination thickness) Δt1 of the powder layer 31, and the filling rate of the powder 20. That is, the drop volume of the modeling liquid 10 is determined by the filling rate of the powder 20 in the powder layer 31 and the thickness of the powder layer 31, and the drop volume fills the void volume included in the unit volume of the powder layer 31. An amount is preferred.

  FIG. 9 shows an example of the relationship between the powder filling rate and the powder layer thickness (Δt1 = 60, 72, 84, 102, 120 μm) determined in this way and the drop volume. FIG. 9 is an example of the relationship between the filling rate of the powder 20 at a certain resolution and the droplet volume of the modeling liquid 10 necessary when the powder 20 of the powder layer 31 has the filling rate.

  In this example, when the powder filling rate is pa, it can be seen that the droplet volume Vj1 or Vj2 is necessary according to the thickness Δt1 of the powder layer 31. Similarly, when the powder filling rate is pb, it can be seen that the droplet volume Vj3 or Vj4 is required according to the thickness Δt1 of the powder layer 31.

  In this way, the drop volume of the modeling liquid is determined.

  Next, an example of a method for controlling the volume of the modeling liquid will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining an example of the relationship between the powder filling rate, the thickness of the powder layer, and the drop volume.

  The drop volume of the modeling liquid 10 discharged from the liquid discharge head 52 varies depending on the powder filling rate and the thickness of the powder layer 31 described above. Therefore, as shown in FIG. 10, the drop volume is divided into ranks 0 to 7 according to the powder filling rate and the thickness of the powder layer 31 in advance.

  Then, the rank is determined at the time of discharge based on the filling rate obtained from the weight detected by the powder weight detection and the thickness of the powder layer 31, and fine adjustment (for example, adjustment of driving voltage, etc.) is performed on the rank. The modeling liquid 10 is discharged with a droplet volume.

  Next, an overview of the overall configuration of the present embodiment will be described with reference to a block diagram of FIG.

  The main control unit 201 acquires image data necessary for modeling from the 3D slice data reading unit 203.

  The main control unit 200 drives and controls the motor driving unit 204 to control the lowering of the modeling stage 24, the rotation and movement of the flattening roller 12, and the movement of the liquid discharge head 52. The formation operation of 31 and the formation operation of the nth layer modeling layer 30 are controlled.

  The modeling stage 24 is raised and lowered by the modeling stage raising and lowering mechanism 212, the flattening roller 12 is rotated and moved by the flattening roller rotating and moving mechanism 215, and the liquid ejection head 52 is moved by the carriage on which the liquid ejection head 52 is mounted. This is performed by a carriage moving mechanism 205 for moving the.

  In addition, the main control unit 200 sends image data to the ejection control unit 202. The discharge controller 202. Based on the received image data, the ejection of the modeling liquid 10 from the liquid ejection head 52 is controlled.

  In addition, the main control unit 200 lowers the weight detection stage 124 every predetermined k layers. The weight detection stage 124 is moved by the weight detection stage elevating mechanism 214. Further, the powder weight detection result detected by the weight sensor 216 of the weight detection stage 124 is temporarily stored in the powder weight detection result storage unit 206. When the total powder weight before and after the formation of the n-th layer is detected and stored and the weight difference is calculated, the powder weight detection result storage unit 206 transmits the weight difference to the main control unit 200, and after transmission , Erase the result.

  The main control unit 200 sets the droplet volume of the modeling liquid 10 based on the calibration curve data from the weight difference received from the powder weight detection result storage unit 206 and transmits the droplet volume to the discharge control unit 202 as a discharge drive condition.

  Next, processing from the modeling start to the modeling end will be described with reference to the flowchart of FIG.

  First, the frequency (feedback frequency) n for performing powder weight detection is set. The feedback frequency n can be set as an integer of 1 or more. The higher the frequency n, the more accurately modeling can be performed by feeding back the change in the powder filling rate more accurately.

  After the start of modeling, at the end of modeling of the kn-1st layer (k = 1, 2, 3,...), The weight detection stage 124 is lowered by the thickness of the powder layer 31 (stacked thickness). The total weight of the powder 20 on the weight detection stage 124 is recorded.

  Next, modeling of the knth layer is started, and at the end of modeling of the knth layer, the total weight of the powder 20 on the weight detection stage 124 is recorded again. From the difference between the two total powder weights, a powder weight change difference (weight difference) Δg before and after the modeling of the knth layer is detected.

  Then, the obtained detection result (weight difference Δg) is transmitted to the main control unit 200.

  Accordingly, the main control unit 200 receives the powder weight change result of the knth layer and calculates the powder filling rate along the calibration curve data. Then, based on the calculated powder filling rate, the drop volume of the modeling liquid 10 in the kn + 1th and subsequent layers is determined, and a change in the discharge condition is transmitted to the discharge control unit 202. The discharge control unit 202 controls the drive of the liquid discharge head 52 from the kn + 1th layer onward according to the new discharge conditions received from the main control unit 200, and discharges the modeling liquid 10.

  These processes are sequentially repeated until the end of modeling to model the target model.

  When the modeling is completed, the main control unit 200 transmits the initial ejection conditions to the ejection control unit 202, and the ejection control unit 202 receives it and returns to the initial setting.

  As described above, by detecting the weight correlated with the filling rate of the powder layer and controlling the droplet volume according to the detected weight, it is possible to perform modeling with a liquid amount without excess or deficiency, Improves accuracy.

  In the description of the above embodiment, in order to facilitate understanding, the filling rate is calculated from the difference in weight change, and the droplet volume corresponding to the filling rate is described as an example. Accordingly, if a table showing the relationship between the weight change difference and the drop volume is prepared, the drop volume information can be obtained from the weight change difference without calculating the filling rate.

  Next, an outline of the three-dimensional modeling apparatus according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 13 is an explanatory schematic plan view of the three-dimensional modeling apparatus, FIG. 14 is an explanatory schematic side view, and FIG. 15 is an explanatory sectional view of the modeling unit. FIG. 15 shows a state during modeling.

  This three-dimensional modeling apparatus is a powder modeling apparatus, in which a modeling part 1 in which a modeling layer 30 that is a layered modeling object in which powder (powder) is combined is formed, and powder that is spread in layers of the modeling part 1 The modeling unit 5 which models the three-dimensional molded item by discharging the modeling liquid 10 to the layer 31 is provided.

  The modeling unit 1 includes a powder tank 11, a flattening roller 12 as a rotating body that is a flattening member (recoater), and the like. The flattening member may be a plate member (blade), for example, instead of the rotating body.

  The powder tank 11 includes a supply tank 21 that supplies the powder 20, a modeling tank 22 in which the modeling layer 30 is stacked and a three-dimensional modeled object is modeled, and a powder weight detection tank 122. The bottom of the supply tank 21 can be raised and lowered in the vertical direction (height direction) as a supply stage 23. Similarly, the bottom of the modeling tank 22 can be moved up and down in the vertical direction (height direction) as the modeling stage 24. A three-dimensional object in which the modeling layer 30 is laminated on the modeling stage 24 is modeled. Further, the bottom of the powder weight detection tank 122 is also movable up and down in the vertical direction (height direction) as the weight detection stage 124.

  The supply stage 23 is raised and lowered in the height direction by, for example, a motor 27 shown in FIG. Similarly, the modeling stage 24 is moved up and down by the motor 28 in the height direction. Similarly, the weight detection stage 124 is moved up and down by the motor 224 in the height direction.

  The flattening roller 12 supplies the powder 20 supplied on the supply stage 23 of the supply tank 21 in the order of the powder weight detection tank 122 and the modeling tank 22, and is leveled by the flattening roller 12 which is a flattening member. Then, the weight detecting powder layer 131 and the modeling powder layer 31 are formed.

  This flattening roller 12 is disposed so as to be capable of reciprocating relative to the stage surface in the direction of arrow Y along the stage surface (surface on which the powder 20 is loaded) of the modeling stage 24, and the rotational movement described above. It is moved by a motor 553 of a reciprocating mechanism 553 constituting the mechanism 215. Further, the flattening roller 12 is rotationally driven by a motor 26.

  On the other hand, the modeling unit 5 includes a liquid discharge unit 50 that discharges the modeling liquid 10 to the powder layer 31 on the modeling stage 24.

  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 hold | maintained so that raising / lowering is possible to the side plates 70 and 70 of both sides.

  The carriage 51 is reciprocated by the X-direction scanning mechanism 550 in the direction of arrow X, which is the main scanning direction, via a main scanning movement mechanism including a motor, a pulley, and a belt.

  The two heads 52a and 52b (hereinafter referred to as “liquid ejection head 52” when not distinguished from each other) have two nozzle arrays in which a plurality of nozzles that eject liquid are arranged. The two nozzle rows of one liquid discharge head 52a discharge a cyan modeling liquid and a magenta modeling liquid. The two nozzle rows of the other liquid discharge 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 liquid discharge heads 52a and 52b via supply tubes and the like. The

  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. The cap 62 is brought into close contact with the nozzle surface of the liquid ejection head 52 (surface on which the nozzle is formed), 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) with the wiper 63 to form a meniscus of the nozzle (the inside of the nozzle is in a negative pressure state). Further, the maintenance mechanism 61 covers the nozzle surface of the liquid discharge head 52 with the cap 62 when the modeling liquid is not discharged, and prevents the powder 20 from being mixed into the nozzle and the modeling liquid 10 from drying. To do.

  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 entire modeling unit 5 is reciprocated in the Y direction by a scanning mechanism including a motor 552.

  The liquid discharge unit 50 is disposed so as to be movable up and down in the arrow 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 including a motor.

  Here, the powder tank 11 of the modeling unit 1 has a box shape, and includes a tank in which the upper surface of the supply tank 21, the modeling tank 22, and the powder weight detection tank 122 is opened. A supply stage 23 is arranged inside the supply tank 21 and a modeling stage 24 is arranged inside the modeling tank 22 so as to be movable up and down. A weight detection stage 124 is disposed inside the powder weight detection tank 122 so as to be movable up and down.

  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 disposed 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. Similarly, the side surface of the weight detection stage 124 is disposed in contact with the inner surface of the powder weight detection tank 122.

  The raising / lowering of the supply stage 23 is performed by the supply stage raising / lowering mechanism 211, the raising / lowering of the modeling stage 24 is performed by the modeling stage raising / lowering mechanism 212, and the weight detection stage 124 is raised / lowered by the weight detection stage raising / lowering mechanism 214, respectively. .

  A powder supply device 554 shown in FIG. 16 is disposed on the supply tank 21. The powder in the tank constituting the powder supply device 554 is supplied to the supply tank 21 during the initial operation of modeling or when the amount of powder in the supply tank 21 decreases. 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 is a layered powder having a predetermined thickness by transferring and supplying the powder 20 from the supply tank 21 to the powder weight detection tank 122 and the modeling tank 22 and leveling the surface. The powder layer 131 for weight detection and the powder layer 31 for modeling are formed.

  The flattening roller 12 is reciprocated in the Y direction (sub-scanning direction) along the stage surface by the reciprocating mechanism 25.

  The flattening roller 12 moves horizontally from the outside of the supply tank 21 so as to pass above the supply tank 21, the powder weight detection tank 122 and the modeling tank 22 while being rotated by the motor 26. Thereby, the powder 20 is transported and supplied onto the powder weight detection tank 122 and the modeling tank 22, and the powder 20 is flattened while the flattening roller 12 passes over the powder weight detection tank 122 and the modeling tank 22. By doing so, the powder layer 131 for weight detection and the powder layer 31 for modeling are formed.

  In addition, a powder removing plate 13 that is a powder removing member for removing the powder 20 attached to the flattening roller 12 in contact with the peripheral surface of the flattening roller 12 is disposed.

  The powder removing plate 13 moves together with the flattening roller 12 while in contact with the peripheral surface of the flattening roller 12. Further, the powder removing plate 13 is arranged in a counter direction when the flattening roller 12 rotates in the rotation direction when flattening.

  Next, an outline of the control unit of the three-dimensional modeling apparatus will be described with reference to FIG. FIG. 16 is a block diagram of the control unit.

  The control unit 500 includes a CPU 501 that controls the entire three-dimensional modeling apparatus, a program that includes a program for causing the CPU 501 to execute a three-dimensional modeling operation including control according to the present invention, and a ROM 502 that stores other fixed data. A main control unit 500A including a RAM 503 for temporarily storing modeling data and the like.

  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 I / F 506 for transmitting and receiving data and signals used when receiving modeling data (slice data) from the external modeling data creation device 600. The modeling data creation device 600 is a device that creates modeling data obtained by slicing a final shaped model into each modeling layer, and is configured by an information processing device such as a personal computer.

  The control unit 500 includes an I / O 507 for taking in detection signals of various sensors. A detection signal of the weight sensor 216 provided on the weight detection stage 124 of the powder weight detection tank 122 is also input to the I / O 507.

  The control unit 500 includes a head drive control unit 508 that drives and controls each liquid discharge head 52 of the liquid discharge unit 50.

  The control unit 500 drives the motor constituting the X-direction scanning mechanism 550 that moves the carriage 51 of the liquid discharge unit 50 in the X direction (main scanning direction), and the modeling unit 5 in the Y direction (sub-scanning). The motor driving unit 512 that drives the motor that constitutes the Y-direction scanning mechanism 552 that is moved in the direction) is provided.

  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 discharge 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 constitutes a supply stage lifting mechanism 211 that lifts and lowers the supply stage 23. In addition, the control unit 500 includes a motor driving unit 514 that drives the motor 28 that constitutes the modeling stage lifting mechanism 212 that moves the modeling stage 24 up and down. In addition, the control unit 500 includes a motor driving unit 524 that drives a motor 224 that constitutes a weight detection stage lifting mechanism 214 that moves the weight detection stage 124 up and down.

  The control unit 500 includes a motor drive unit 515 that drives a motor 553 of a reciprocating mechanism that moves the flattening roller 12, and a motor drive unit 516 that drives a motor 26 that rotationally drives the flattening roller 12.

  The control unit 500 includes a supply system drive unit 517 that drives a powder supply device 554 that supplies the powder 20 to the supply tank 21, and a maintenance drive unit 518 that drives the maintenance mechanism 61 of the liquid discharge unit 50.

  The I / O 507 of the controller 500 receives detection signals from a temperature / humidity sensor that detects temperature and humidity as environmental conditions of the apparatus, a weight sensor 216, and other sensors.

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

  The modeling data creating apparatus 600 and the three-dimensional modeling apparatus (powder additive modeling apparatus) 601 constitute a three-dimensional molding system as an apparatus according to the present invention.

  Also in this three-dimensional modeling apparatus, as described above, the total weight of the powder 20 on the weight detection stage 124 of the powder weight detection tank 122 is detected, and the weight detection powder layer 131 corresponding to the powder layer 31 is detected. The weight is detected as a weight difference, and the drop volume of the modeling liquid is controlled according to the weight difference.

DESCRIPTION OF SYMBOLS 1 Modeling part 5 Modeling unit 10 Modeling liquid 12 Flattening roller (flattening means, rotating body)
20 Powder 21 Supply tank 22 Modeling tank 23 Supply stage 24 Modeling stage 30 Modeling layer (layered model)
31 Powder layer (layered powder)
DESCRIPTION OF SYMBOLS 50 Liquid discharge unit 51 Carriage 52 Liquid discharge head 122 Powder weight detection tank 124 Weight detection stage 216 Weight sensor

Claims (8)

A three-dimensional modeling apparatus that discharges liquid to a powder layer, forms a layered structure that combines the powders of the powder layer, and forms a three-dimensional structure by stacking the layered structure,
Liquid ejection means for ejecting the liquid;
A modeling tank in which the layered model is formed,
Powder weight detection capable of supplying the powder and forming a powder layer for weight detection with the same thickness as the powder layer when the powder is supplied to the modeling tank to form the powder layer A tank,
Weight detection means for detecting the weight of the powder layer for weight detection in the powder weight detection tank;
Means for controlling the drop volume of the modeling liquid ejected by the liquid ejection means from the detection result of the weight detection means. The modeling tank has a modeling stage capable of moving up and down on which the layered model is stacked,
The powder weight detection tank has a weight detection stage capable of moving up and down to which the powder is supplied,
The three-dimensional modeling apparatus according to claim 1, wherein the modeling stage and the weight detection stage are driven by different drive mechanisms. The three-dimensional object according to claim 2, wherein the modeling tank and the powder weight detection tank have the same width in a direction perpendicular to the moving direction of the flattening means for leveling the supplied powder. Modeling equipment. The controlling means determines the droplet volume based on a filling rate of the powder in the powder layer and a thickness of the powder layer, and the droplet volume is a void volume included in a unit volume of the powder layer. The three-dimensional modeling apparatus according to claim 1, wherein the three-dimensional modeling apparatus is an amount to be filled. The weight of the weight detection powder layer formed when the n-th powder layer is formed is the total weight of the powder in the weight detection tank immediately before the formation of the n-th powder layer. 5. The three-dimensional modeling apparatus according to claim 1, wherein a difference between a weight and a total weight of the powder in the weight detection tank immediately after forming the n-th powder layer is set. . The three-dimensional modeling according to any one of claims 1 to 5, wherein the detection by the weight detection means is performed when the powder layer is formed next after forming two or more powder layers. apparatus. It is a three-dimensional modeling method for discharging a liquid to a powder layer, forming a layered structure that combines the powders of the powder layer, and layering the layered structure to form a three-dimensional structure,
When the powder layer is formed by supplying the powder to the modeling tank in which the layered structure is formed, the powder is supplied to the powder weight detection tank and has the same thickness as the powder layer. Forming a powder layer for detection,
Detecting the weight of the powder layer for weight detection in the powder weight detection tank;
A three-dimensional modeling method characterized by controlling a drop volume of the modeling liquid ejected by the liquid ejection means from a detection result of the weight of the weight detection powder layer. A program for discharging a liquid to a powder layer, forming a layered structure that combines the powders of the powder layer, and stacking the layered structure to form a three-dimensional structure. There,
When the powder layer is formed by supplying the powder to the modeling tank in which the layered structure is formed, the powder is supplied to the powder weight detection tank and has the same thickness as the powder layer. A process for forming a powder layer for detection;
Processing for detecting the weight of the powder layer for weight detection in the powder weight detection tank;
The program for making a computer perform the process which controls the drop volume of the said modeling liquid discharged with the said liquid discharge means from the detection result of the weight of the said powder layer for weight detection.

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