Construction methods

Abstract

This provides a 3D printing method for forming structures that can reliably improve the uneven shape of the sides of structures. [Solution] The method comprises a lamination step in which a lamination material 15 is laminated in the lamination direction Z by a first extrusion device 10 equipped with a first extrusion nozzle 11 that can move relative to the structure 50, and a modification step in which a modification material 25 is deposited at multiple locations in the lamination direction Z that are different in position toward a recess C4 formed on the side surface 55 of the structure 50 in the lamination step by a second extrusion device 20 equipped with a plurality of second extrusion nozzles 21a, 21b, 21c that can move relative to the structure 50, and the lamination step and the modification step are repeated multiple times to form the structure 50.

Description

Technical Field

[0001] The present invention relates to a method for forming a structure.

Background Art

[0002] In recent years, the applications of 3D printers have been rapidly expanding, and their deployment in construction applications utilizing the material extrusion method has attracted attention. The material extrusion method has advantages such as enabling the shaping of large structures, but conventionally, there has been a problem that concavo-convex shapes are formed on the side surfaces of structures. In contrast, for example, Patent Document 1 proposes a method for forming a structure to improve such concavo-convex shapes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described method for forming a structure, there is a possibility that the improvement of the concavo-convex shape may be incomplete when the concavo-convex on the side surface is large. An object of the present invention is to provide a method for forming a structure by a 3D printer that can surely improve the concavo-convex shape on the side surface of the structure.

Means for Solving the Problems

[0005] The present invention is a method for forming a structure, comprising: a lamination step of forming a structure by laminating lamination material in the lamination direction using a first extrusion device equipped with a first extrusion nozzle capable of relative movement with respect to the structure; and a modification step of depositing modification material at multiple locations in the lamination direction that are different in position towards recesses formed on the side surface of the structure in the lamination step using a second extrusion device equipped with a plurality of second extrusion nozzles capable of relative movement with respect to the structure, wherein the lamination step and the modification step are repeated multiple times. [Effects of the Invention]

[0006] According to an aspect of the present invention, a method for forming a structure using a 3D printer can be provided that can reliably improve the uneven shape of the side surface of the structure. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing the structure formation method of this embodiment. [Figure 2] This is a top view showing the structure formation method of this embodiment. [Figure 3] This is a front view (cross-sectional view) showing the structure formation method of this embodiment. [Figure 4] This is a side view (cross-sectional view) illustrating the structural formation method of this embodiment. [Figure 5] This is a side view (cross-sectional view) illustrating the structural formation method of this embodiment. [Figure 6] This is a side view (cross-sectional view, enlarged view of Figure 5) showing the structural formation method of this embodiment. [Figure 7] This is a block diagram showing the configuration of the second extrusion apparatus of this embodiment. [Modes for carrying out the invention]

[0008] The following describes the structural formation method of the embodiment of the present invention with reference to Figures 1 to 7.

[0009] Figure 1 is a perspective view showing the structure formation method of this embodiment.

[0010] As shown in Figure 1, the structure 50 comprises layers L1, L2, and L3. The structure 50 extends in a horizontal direction X, and Figure 1 shows a portion of it. The first extruder 10 is a device that constitutes a material extrusion type 3D printer and includes a first extruder nozzle 11, a material supply device 12 (not shown), and a pressure feed device 13 (not shown). The pressure feed device 13 pressure feeds the lamination material 15 from the material supply device 12 to the first extruder nozzle 11, and the lamination material 15 is continuously discharged from the first extruder nozzle 11. The first extrusion nozzle 11 is movable relative to the structure 50 by a positioning means (not shown). This positioning means may be a robotic arm type or a gantry type device.

[0011] The first extrusion nozzle 11 moves along the direction X from a position spaced apart from the layer L3 in the lamination direction Z, and continuously extrudes the lamination material 15 onto the layer L3. The lamination material 15 extruded onto the layer L3 becomes one with the layer L3 to form layer L4, which becomes part of the structure 50. Layers L1, L2, and L3 are sequentially stacked along direction Z through a process similar to that of layer L4 described above. The number of such layers is not limited to four (layers L1 to L4), but can be any number of layers.

[0012] The lamination material 15 is a material such as mortar, concrete, or geopolymer, which is fluid when extruded from the first extrusion nozzle 11, but hardens over time after extrusion.

[0013] The above process corresponds to the lamination process.

[0014] Figure 2 is a top view showing the structure formation method (partially a cross-sectional view along the interface between layer L3 and layer L4).

[0015] As shown in FIGS. 1 and 2, the second extrusion device 20 is a device that constitutes a 3D printer of the material extrusion type, and includes a total of three second extrusion nozzles 21a, 21b, and 21c. The number of the second extrusion nozzles is not limited to three of the second extrusion nozzles 21a, 21b, and 21c, and any number may be used as long as there are a plurality of them.

[0016] The second extrusion device 20 may include an extrusion head 27, and the second extrusion nozzles 21a, 21b, and 21c may be built into the extrusion head 27.

[0017] The second extrusion nozzles 21a, 21b, and 21c may be connected to the first extrusion nozzle 11 via the extrusion head 27 and a connecting member 70 or the like. Thus, when the first extrusion nozzle 11 moves along the direction X, the second extrusion nozzles 21a, 21b, and 21c can also move along the direction X together with it.

[0018] [[ID=1,2]]図3は、構造物形成方法を示す正面図であり、図2の断面E-Eでの断面図である。

[0019] As shown in FIG. 3, the second extrusion nozzles 21a, 21b, and 21c may be arranged along a straight line S in a direction R that is inclined with respect to the direction Z. Also, among the second extrusion nozzles 21a, 21b, and 21c, two second extrusion nozzles adjacent in the direction Z may be arranged along the direction R. In these cases, among the second extrusion nozzles 21a, 21b, and 21c, when looking at the second extrusion nozzles adjacent in the direction Z, for example, the second extrusion nozzles 21b and 21c, the interval N in the direction Z is smaller than the interval M in the direction R.

[0020] 図4は、構造物形成方法を示す側面図であり、図3の断面A-Aでの断面図である。

[0021] [[ID=,27]] As shown in Figures 1 to 4, in the lamination process described above, the first extrusion nozzle 11 continuously discharges the lamination material 15 onto layer L3, and when the lamination material 15 becomes layer L4, a striated recess C4 is formed on the side surface 55 of the structure 50 at the boundary between layer L3 and layer L4. This corresponds to the uneven shape of the side surface 55 of the structure 50.

[0022] Figure 5 is a side view showing the structure formation method, and is a cross-sectional view of section BB in Figure 3.

[0023] As shown in Figures 1 to 3 and Figure 5, the repair material 25 is discharged from the second extrusion nozzles 21a, 21b, and 21c toward the recess C4, and the repair material 25 is deposited in the recess C4.

[0024] Figure 4 shows the shape of the recess C4 before the deposition of the repair material 25, and Figure 5 shows the shape of the repaired portion D4, which is an improvement over the recess C4, after the deposition of the repair material 25. As shown in Figures 1 to 3, the second extrusion nozzles 21a, 21b, and 21c extrude the modification material 25 as they move along the direction X, so that the modification material 25 extruded toward the recess C4 is deposited along the direction X.

[0025] The correction material 25 is a material such as mortar, concrete, geopolymer, cement mortar, or polymer cement mortar, and can be appropriately selected from materials that are fluid when extruded from the second extrusion nozzles 21a to 21c but harden over time after extrusion.

[0026] Figure 6 is a side view showing the structure formation method, and is an enlarged cross-sectional view of area G in Figure 5.

[0027] As shown in Figures 1, 3, and 6, since the second extrusion nozzles 21a, 21b, and 21c are located at different positions in direction Z, the correction material 25 discharged from the second extrusion nozzles 21a, 21b, and 21c accumulates at multiple locations at different positions in direction Z, forming correction sections Da, Db, and Dc. These correction sections Da, Db, and Dc then combine to form correction section D4. As a result, the recess C4 is covered with the correction material 25, and the recess C4 is reliably improved into correction section D4. In other words, it is possible to reliably improve the uneven shape of the side surface 55 of the structure 50. The surface of the modified portion D4 may have a smoothed shape that is continuous with the area of ​​the side surface 55 other than the modified portion D4.

[0028] The area of ​​the recess C4 covered by the modification material 25 is not limited to the entire recess C4; it is sufficient if at least a portion of the recess C4 is covered by the modification material 25. The surface of the modified portion D4 may have a concave shape with a reduced depth compared to the recess C4.

[0029] As shown in Figures 1 and 3, on any surface with the same position in direction X, for example, surface F (Figure 3), the correction material 25 (corresponding to the correction part Dc) extruded from the second extrusion nozzle 21c located below in direction Z may reach and deposit in the recess C4 before the correction material 25 (corresponding to the correction part Db) extruded from the second extrusion nozzle 21b located above in direction Z. The same method as described above can also be applied to the second extrusion nozzle 21b and the second extrusion nozzle 21a.

[0030] As shown in Figures 4 and 5, modified parts D2 and D3 are improved from recesses C2 and C3, respectively, through a process similar to that of modified part D4. The number of such modified parts is not limited to three (D2, D3, and D4), but may be any number.

[0031] As shown in Figure 6, the depth 53b of the recess C4 corresponding to the deposition position of the correction material 25 (corresponding to the correction part Db) discharged from the second extrusion nozzle 21b may be defined as the average value of the depth of the recess C4 in the range from position P, which is N / 2 away from the center R in the opposite direction Z to the center R, to position Q, which is N / 2 away from the center R in the direction Z. The same definition can also be applied to the depths 53a and 53c corresponding to the deposition positions of the correction material 25 (corresponding to the correction parts Da and Dc) discharged from the second extrusion nozzles 21a and 21c, respectively. In the above case, depth 53b is greater than depth 53a, and depth 53b is also greater than depth 53c.

[0032] The flow rates of the modification material 25 discharged from the second extrusion nozzles 21a, 21b, and 21c are defined as flow rates Va, Vb, and Vc, respectively. In this case, the flow rates Va, Vb, and Vc may be different from each other.

[0033] Furthermore, the greater the depth 53a, 53b, 53c at which the correction material 25 is deposited, the greater the flow rates Va, Vb, Vc from the corresponding second extrusion nozzles 21a, 21b, 21c may be. That is, in the above example, the flow rate Vb may be greater than the flow rate Va, and the flow rate Vb may be greater than the flow rate Vc.

[0034] The flow rates Va, Vb, and Vc may be made different from each other by making the shapes of the second extrusion nozzles 21a, 21b, and 21c different from each other. For example, the flow rate Vb may be made larger than the flow rates Va and Vc by making the inner diameter of the second extrusion nozzle 21b larger than the inner diameters of the second extrusion nozzles 21a and 21c.

[0035] Figure 7 is a block diagram showing the configuration of the second extruder 20.

[0036] As shown in Figure 7, the second extruder 20 may further include a material supply device 22, a pressure feed device 23, and a plurality of flow rate adjustment devices 26a, 26b, 26c.

[0037] The material supply device 22 may supply the correction material 25 to the pumping device 23. The material supply device 22 can be configured in any way, such as a hopper and a stirring screw. The pumping device 23 may pump the correction material 25 supplied from the material supply device 22 to the flow rate adjustment devices 26a, 26b, and 26c at a predetermined pressure. The pumping device 23 can be any configuration, such as a screw pump, lobe pump, or gear pump. Branched flow paths may be provided between the pumping device 23 and the flow rate adjustment devices 26a, 26b, and 26c, with the correction material 25 flowing into each of the flow rate adjustment devices 26a, 26b, and 26c, respectively. The flow rate adjusters 26a, 26b, and 26c may each individually adjust the flow rate of the correcting material 25 flowing toward the second extrusion nozzles 21a, 21b, and 21c. The flow rate adjusters 26a, 26b, and 26c can be any configuration such as a needle valve, pinch valve, or rotary valve. From the second extrusion nozzles 21a, 21b, and 21c, the modification material 25 is continuously discharged at flow rates Va, Vb, and Vc, respectively, and reaches and deposits in the recess C4 of the side surface 55.

[0038] Flow rate adjusters 26a, 26b, and 26c may be used to make the flow rates Va, Vb, and Vc different from each other. The shapes of the second extrusion nozzles 21a, 21b, and 21c may be identical to each other.

[0039] The second extrusion apparatus 20 further includes a control device 28 that controls the flow rate adjustment devices 26a, 26b, and 26c, and the control device 28 may control the flow rates Va, Vb, and Vc respectively. For example, by setting the flow rate values ​​Va, Vb, and Vc in the control device 28, the control device 28 may control the flow rate adjusters 26a, 26b, and 26c so that the flow rates become Va, Vb, and Vc.

[0040] The extrusion head 27 may also have flow rate adjustment devices 26a, 26b, and 26c built into it. Alternatively, the extrusion head 27 may have an inlet 24 between the pumping device 23 and the flow rate adjustment devices 26a, 26b, and 26c.

[0041] The above steps correspond to the correction process. The structure 50 is formed by repeating the above lamination process and the above modification process.

[0042] Next, the effects of the above embodiment will be explained.

[0043] The structure formation method of this embodiment comprises a lamination step of forming a structure 50 by laminating lamination material 15 in the lamination direction Z using a first extrusion device 10 equipped with a first extrusion nozzle 11 that can move relative to the structure 50, and a modification step of depositing modification material 25 at multiple locations in the lamination direction Z that are different in position toward a recess C4 formed on the side surface 55 of the structure 50 in the lamination step using a second extrusion device 20 equipped with a plurality of second extrusion nozzles 21a, 21b, 21c that can move relative to the structure 50, and repeating the lamination step and the modification step multiple times. This makes it possible to reliably improve the uneven shape of the side surface 55 of the structure 50.

[0044] The flow rates Va, Vb, and Vc of the modification material 25 may be made different among the second extrusion nozzles 21a, 21b, and 21c. This allows the material to be adapted to the shape of the recess C4 and the degree of sagging due to gravity after the repair material 25 is deposited into the recess C4, thereby enabling more reliable improvement of the uneven shape.

[0045] The greater the depth of the recess C4 where the modification material 25 is deposited between the second extrusion nozzles 21a, 21b, and 21c, the greater the flow rates Va, Vb, and Vc from the corresponding second extrusion nozzles 21a, 21b, and 21c. This allows the design to adapt to the uneven surface, making it possible to further improve the shape of the uneven surface.

[0046] Multiple flow rate adjustment devices 26a, 26b, and 26c, each provided upstream of the second extrusion nozzles 21a, 21b, and 21c, may individually adjust the flow rates Va, Vb, and Vc, respectively. This allows for precise adjustment of the flow rates Va, Vb, and Vc, making it possible to further improve the uneven surface shape.

[0047] A pumping device 23, which is commonly provided upstream of the flow rate adjustment devices 26a, 26b, and 26c, may pump the correction material 25 toward the flow rate adjustment devices 26a, 26b, and 26c. This stabilizes the pressure acting on the flow rate regulators 26a, 26b, and 26c, making it possible to adjust the flow rates Va, Vb, and Vc more precisely.

[0048] The control device 28 may control each of the flow rate adjusters 26a, 26b, and 26c. This makes it possible to quickly adjust the flow rates Va, Vb, and Vc.

[0049] The shapes of the second extrusion nozzles 21a, 21b, and 21c may be different from each other. This makes it possible to stably generate differences between the flow rates Va, Vb, and Vc.

[0050] Two of the second extrusion nozzles 21a, 21b, and 21c that are adjacent to each other in direction Z may be arranged along direction R, which is inclined with respect to direction Z. This allows two adjacent second extrusion nozzles 21a, 21b, and 21c to be arranged close together in direction Z. As a result, the correction material 25 for correcting the recess C4 can be concentrated and deposited, making it possible to reliably improve the uneven shape even when the depth of the uneven shape is large.

[0051] Furthermore, the second extrusion nozzles 21a, 21b, and 21c may be arranged along a straight line S in direction R. This allows the second extrusion nozzles to be densely arranged over a wide range in direction Z. As a result, the correction material 25 for correcting the recesses C4 can be concentrated and deposited over a wide range in direction Z, making it possible to more reliably improve the uneven shape even when the depth of the uneven shape is large.

[0052] On a plane perpendicular to direction X, the modification material 25 extruded from the second extrusion nozzle 21c located below may reach the recess C4 before the modification material 25 extruded from the second extrusion nozzle 21b located above. As a result, when the correction material 25 extruded from the second extrusion nozzle 21b is deposited in the recess C4, the correction material 25 extruded from the second extrusion nozzle 21c is already present below it and provides support. This reduces the effect of gravity-induced sagging of the correction material 25, making it possible to further reliably improve the uneven shape.

[0053] The first extrusion nozzle 11 and the second extrusion nozzles 21a, 21b, and 21c may be connected. The first extrusion nozzle 11 and the second extrusion nozzles 21a, 21b, and 21c can be stably moved relative to each other in direction X, making it possible to further reliably improve the uneven shape.

[0054] Next, a modified example of the above embodiment will be described.

[0055] The first extrusion nozzle 11 and the second extrusion nozzles 21a, 21b, and 21c may be fixed, while the structure 50 moves. Alternatively, the first extrusion nozzle 11 and the second extrusion nozzles 21a, 21b, and 21c may not be connected to each other, and may move independently relative to the structure 50.

[0056] Direction R is not limited to being inclined with respect to direction Z; direction R may also be parallel to direction Z.

[0057] The arrangement of the second extrusion nozzles 21a, 21b, and 21c is not limited to a straight line, but may be curved, matrix-shaped, staggered, or the like. Furthermore, in these arrangements, two second extrusion nozzles adjacent to each other in direction Z may be arranged along direction R.

[0058] The definition of the depth of recess C4 is not limited to the above example. The depth of recess C4 may also be defined as the maximum depth of recess C4 within the above range.

[0059] The flow rates Va, Vb, and Vc may be the same value. This makes it possible to easily modify the recess C4. Furthermore, the flow rates Va, Vb, and Vc may be different from each other, regardless of the relative sizes of the depths 53a, 53b, and 53c. This makes it possible to reduce the effects of gravity-induced sagging of the correction material 25 after deposition.

[0060] The flow rate adjusters 26a, 26b, and 26c may be omitted. In this case, the flow rates Va, Vb, and Vc are determined primarily by the pumping pressure of the pumping device 23 and the flow resistance of the second extrusion nozzles 21a, 21b, and 21c. Alternatively, the pumping device 23 may be individually installed upstream of each of the flow rate adjustment devices 26a, 26b, and 26c. In this case, the flow rates Va, Vb, and Vc can be individually adjusted by the pumping pressure of each pumping device 23.

[0061] The modification material 25 may be the same as the lamination material 15. In this case, the material supply device 22 may be omitted, and the modification material 25 (lamination material 15) may be supplied from the material supply device 12 to the pressure feeding device 23. Alternatively, the pumping device 23 may be omitted, and the modification material 25 (lamination material 15) may be pumped from the pumping device 13 towards the flow rate adjustment devices 26a, 26b, and 26c.

[0062] Direction X may be a direction inclined with respect to the horizontal.

[0063] The present invention is not limited to the above embodiments and modifications, and various modifications are possible. [Explanation of Symbols]

[0064] 10 First extruder 11 First extrusion nozzle 15 Lamination Materials 20 Second extruder 21a, 21b, 21c Second extrusion nozzle 25 Correction materials 26a, 26b, 26c flow regulator 50 Structures 53a, 53b, 53c Depth of recess 55 Side view C2, C3, C4 recesses D2, D3, D4 Correction Section L1, L2, L3, L4 layers R Arrangement direction of the second extrusion nozzle Va, Vb, Vc: Flow rate of material for modification. X relative movement direction Z stacking direction

Claims

1. A lamination process in which a lamination material is stacked in the lamination direction by a first extrusion apparatus equipped with a first extrusion nozzle capable of relative movement with respect to the structure, A modification step in which a modification material is deposited at multiple locations in the lamination direction that are different in position in the lamination direction toward a recess formed on the side surface of the structure in the lamination step, using a second extrusion apparatus equipped with a plurality of second extrusion nozzles that are movable relative to the structure, Equipped with, A method for forming a structure, which involves repeating the lamination process and the modification process multiple times.

2. The method for forming a structure according to claim 1, wherein the flow rates of the modification material between the second extrusion nozzles are made different from those of the other.

3. The method for forming a structure according to claim 2, wherein the greater the depth of the recess where the modification material is deposited between the second extrusion nozzles, the greater the flow rate of the modification material from the corresponding second extrusion nozzle.

4. The method for forming a structure according to claim 2, wherein a plurality of flow rate adjustment devices provided upstream of each of the second extrusion nozzles individually adjust the flow rate of the modification material in each of the second extrusion nozzles.

5. The method for forming a structure according to claim 4, wherein a pumping device commonly provided upstream of the flow rate adjustment device pumps the modification material toward the flow rate adjustment device.

6. The method for forming a structure according to claim 4, wherein the control device controls each of the flow rate adjustment devices.

7. The method for forming a structure according to claim 2, wherein the shapes of the second extrusion nozzles are different from each other.

8. The method for forming a structure according to claim 1, wherein two second extrusion nozzles adjacent to each other in the stacking direction are arranged along a direction inclined with respect to the stacking direction.

9. The method for forming a structure according to claim 8, wherein the second extrusion nozzles are arranged along a straight line in a direction inclined with respect to the stacking direction.

10. The method for forming a structure according to claim 8, wherein, on a plane perpendicular to the direction of relative movement, the modification material extruded from the second extrusion nozzle located below reaches the recess before the modification material extruded from the second extrusion nozzle located above.

11. The method for forming a structure according to claim 1, wherein the first extrusion nozzle and the second extrusion nozzle are connected.

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