Object molding method

Abstract

To provide an object molding method that can increase strength against forces acting in the front-rear direction while suppressing man-hour numbers.SOLUTION: An object molding method for forming a molded object by laminating a cement-based material with a laminate-molding machine includes a lower layer forming step of discharging cement-based material from the laminate-molding machine to form lower layers that have at least either a recess or a protrusion on an upper surface, and an upper layer forming step of discharging cement-based material from the laminate-molding machine to form upper layers that have at least either an upper protrusion that engages with the recess or an upper recess that engages with the protrusion on the lower surface, and that are placed on the upper surface of the lower layers.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for forming an object by layering a cement-based material using a layer-by-layer manufacturing machine. [Background technology]

[0002] Objects manufactured by layering cementitious materials tend to have low strength against forces acting in the horizontal direction. In particular, because additive manufacturing machines discharge cementitious material from a discharge port while moving the discharge port forward, there is a problem that the strength against forces acting in the horizontal direction (front-to-back direction) of the movement of the discharge port is low. To address this problem, Patent Document 1 discloses a technology in which a reinforcing material is inserted through the cementitious materials layered one above the other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-194790 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique described in Patent Document 1 requires a step of inserting a reinforcing material in addition to the step of layering the cement-based material, which increases the number of steps required to form a shaped object.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a method for forming a molded object that can increase strength against forces acting in the forward and backward directions while suppressing an increase in labor hours. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the method for forming a molded object according to the present disclosure is a method for forming a molded object by layering a cement-based material with an additive manufacturing machine, and includes a lower layer forming step of discharging the cement-based material from the additive manufacturing machine to form a lower layer having at least one of a concave portion and a convex portion on an upper surface thereof, and an upper layer forming step of discharging the cement-based material from the additive manufacturing machine to form an upper layer having at least one of an upper convex portion that engages with the concave portion and an upper concave portion that engages with the convex portion on its lower surface, and which is placed on the upper surface of the lower layer.

[0007] In order to achieve the above-mentioned object, the method for forming a molded object according to the present disclosure is a method for forming a molded object by layering a cement-based material with an additive manufacturing machine, and includes a lower layer forming step of discharging the cement-based material from the additive manufacturing machine to form a lower layer whose upper surface is inclined at a predetermined angle with respect to the front-to-rear direction, and an upper layer forming step of discharging the cement-based material from the additive manufacturing machine to form an upper layer that is placed on the upper surface of the lower layer.

[0008] In order to achieve the above-mentioned object, the method for forming a molded object according to the present disclosure is a method for forming a molded object by layering a cement-based material with an additive manufacturing machine, and includes: a lower layer forming step of discharging the cement-based material from the additive manufacturing machine to form a lower layer having an upper surface that includes at least one of a concave portion and a convex portion, and the upper surface of which is inclined at a predetermined angle with respect to the front-to-rear direction; and an upper layer forming step of discharging the cement-based material from the additive manufacturing machine to form an upper layer having an upper surface that includes at least one of an upper convex portion that engages with the concave portion and an upper concave portion that engages with the convex portion, and which is placed on the upper surface of the lower layer. [Effects of the Invention]

[0009] According to the method for forming a structure disclosed herein, it is possible to provide a structure that has increased strength against forces acting in the front-rear direction while suppressing an increase in the number of steps. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a schematic configuration of a layered manufacturing machine according to an embodiment; [Figure 2] 1 is a flowchart illustrating a method for forming an object according to an embodiment. [Figure 3] FIG. 10 is a diagram illustrating an example of a base layer forming step according to an embodiment. [Figure 4] 10 is an example of a flowchart of a base layer forming step. [Figure 5] 5 is a diagram for explaining an example of the first layer forming step shown in FIG. 4. FIG. [Figure 6] 5 is a diagram for explaining an example of the second layer forming step shown in FIG. 4. FIG. [Figure 7] 10A to 10C are diagrams illustrating an example of a lower layer forming step according to an embodiment. [Figure 8] 10A to 10C are diagrams illustrating an example of an upper layer forming step according to an embodiment. [Figure 9] FIG. 2 is an enlarged view of a lower layer and an upper layer according to one embodiment. [Figure 10A] 1A and 1B are diagrams illustrating schematic configurations of lower and upper layers according to some embodiments. [Figure 10B] 1A and 1B are diagrams illustrating schematic configurations of lower and upper layers according to some embodiments. [Figure 11A] FIG. 10 is a diagram schematically illustrating a configuration of a nozzle according to a first modified example. [Figure 11B] FIG. 10 is a diagram schematically illustrating a configuration of a nozzle according to a first modified example. [Figure 11C] FIG. 10 is a diagram schematically illustrating the configuration of a lower layer and an upper layer laminated by a nozzle according to a first modified example. [Figure 11D] FIG. 10 is a diagram schematically illustrating a configuration of a nozzle according to a second modified example. [Figure 11E] FIG. 10 is a diagram schematically illustrating the configuration of a lower layer and an upper layer laminated by a nozzle according to a second modified example. [Figure 12A] FIG. 10 is a diagram schematically illustrating a configuration of a nozzle according to a third modified example. [Figure 12B]FIG. 10 is a diagram schematically illustrating a configuration of a nozzle according to a third modified example. [Figure 13] FIG. 10 is a perspective view schematically showing the configuration of a nozzle according to a fourth modified example. [Figure 14] FIG. 10 is a perspective view schematically showing the configuration of a nozzle according to a fifth modified example. [Figure 15] FIG. 1 is a perspective view schematically illustrating a nozzle configuration according to some embodiments. [Figure 16] FIG. 16 is a perspective view showing an example of a model formed by performing a model forming method according to an embodiment using the nozzle shown in FIG. 15. [Figure 17] 1 is a flowchart illustrating a method for forming an object according to some embodiments. [Figure 18] 10A and 10B are diagrams illustrating an example of a sideways step according to some embodiments. [Figure 19] 10 is a flowchart illustrating a method for forming an object according to another embodiment. [Figure 20] FIG. 10 is a diagram illustrating an example of a base layer forming step according to another embodiment. [Figure 21] 10A to 10C are views for explaining an example of a lower layer forming step according to another embodiment. [Figure 22] 10A to 10C are views for explaining an example of an upper layer forming step according to another embodiment. [Figure 23] 10 is a flowchart showing a method for forming an object according to yet another embodiment. [Figure 24] 10A to 10C are views for explaining an example of a lower layer forming step according to yet another embodiment. [Figure 25] 10A to 10C are views for explaining an example of an upper layer forming step according to yet another embodiment. [Figure 26] 10 is an example of a flowchart of a base layer forming step. [Figure 27] 27 is a diagram for explaining an example of the oblique layer forming step shown in FIG. 26. FIG. [Figure 28] 27 is a diagram for explaining an example of the first layer forming step shown in FIG. 26. FIG. [Figure 29] 27 is a diagram for explaining an example of the second layer forming step shown in FIG. 26. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a method for forming a molded object according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0012] In the method for manufacturing a model according to the present disclosure, a cement-based material is layered using a layer-by-layer manufacturing machine 1 to manufacture a model. First, an example of the configuration of the layer-by-layer manufacturing machine 1 will be described with reference to FIG.

[0013] <Additive manufacturing machine> FIG. 1 is a diagram schematically illustrating an example of the configuration of an additive manufacturing machine 1. As shown in FIG. 1, the additive manufacturing machine 1 includes a nozzle 2 and a movement mechanism 4. In the embodiment illustrated in FIG. 1, the additive manufacturing machine 1 further includes a supply pump 6 and a control device 10. The cementitious material M is, for example, mortar or concrete, and is produced by mixing water, cement, aggregate, and the like. The cementitious material M may be made from limestone, which is primarily composed of calcium carbonate, or may be made from gypsum, fly ash, blast furnace slag, molten slag, siliceous admixture, sewage incineration sludge, kaolin, incineration ash, or the like.

[0014] The nozzle 2 has an opening at its tip, and discharges the cementitious material M from the opening 2a. The movement mechanism 4 moves the nozzle 2 in the up-down direction D2. In the embodiment illustrated in FIG. 1, the movement mechanism 4 is an arm that supports the nozzle 2. The arm is electrically connected to the control device 10 and moves in any direction according to instructions from the control device 10. That is, the nozzle 2 is movable in the up-down direction D2 and in the horizontal direction. In the present disclosure, the horizontal direction in which the nozzle 2 moves while discharging the cementitious material M from the nozzle 2 is defined as the front-rear direction D1. The nozzle 2 discharges the cementitious material M while moving forward. Note that the movement mechanism 4 is not limited to the arm illustrated in FIG. 1, as long as it can move the nozzle 2 in the up-down direction D2. Note that the front-rear direction D1 may coincide with the width direction of the object 100, the depth direction of the object 100, or a direction inclined with respect to both the width direction and the depth direction of the object 100.

[0015] The supply pump 6 supplies the cementitious material M to the nozzle 2. The supply pump 6 is electrically connected to the control device 10, and supplies the amount of cementitious material M to the nozzle 2 in accordance with instructions from the control device 10.

[0016] The control device 10 is a device for controlling the amount of cement-based material M discharged from the nozzle 2 and the movement of the nozzle 2 in order to form a model 100 having a desired shape. The control device 10 is a computer such as an electronic control device, and includes a processor such as a CPU or GPU (not shown), memories such as ROM and RAM, and an I / O interface. The processor of the control device 10 operates (performs calculations, etc.) according to instructions of a program loaded into the memory, and the control device 10 transmits instructions to each device (the arm and supply pump 6 described above) included in the additive manufacturing machine 1. In some embodiments, the control device 10 is configured to be able to receive signals for understanding the status of each device. In some embodiments, the control device 10 is a cloud server provided in a cloud environment.

[0017] <How to create a model> The following describes a method for manufacturing a model 100 using the above-described additive manufacturing machine 1. In some embodiments, the model 100 is a first model 100a (100) manufactured by layering a cementitious material M to form a concave-convex shape, as shown in FIG. 1(a). In some embodiments, the model 100 is a second model 100b (100) manufactured by layering a cementitious material M to form a slope, as shown in FIG. 1(b). In some embodiments, the model 100 is a third model 100c (100) manufactured by layering a cementitious material M to form both a concave-convex shape and a slope, as shown in FIG. 1(c). In some embodiments, the object 100 is a fourth object 100d (100) that includes a first inclined portion 101a formed by stacking cement-based material M to form a slope, as shown in (d) of Figure 1, and a second inclined portion 101b formed by stacking cement-based material M to form a slope that intersects with the slope of the first inclined portion 101a, and the second inclined portion 101b is connected to the first inclined portion 101a in the front-to-back direction D1.

[0018] 2 is a flowchart showing a method for forming an object according to an embodiment. As shown in FIG. 2, the method for forming an object includes a lower layer forming step S1 and an upper layer forming step S2. In one embodiment, the method for forming an object further includes a base layer forming step S3 that is performed before the lower layer forming step S1, and the base layer forming step S3, the lower layer forming step S1, and the upper layer forming step S2 are performed in this order. The object 100 is, for example, a building such as a house or a warehouse.

[0019] FIG. 3 is a diagram illustrating an example of a base layer forming step S3 according to one embodiment. As shown in FIG. 3 , in the base layer forming step S3, cementitious material M is discharged from a nozzle 2 of an additive manufacturing machine 1 onto a buildup surface 21 on which the cementitious material M is to be layered, to form a base layer 22 having an uneven upper surface 23. A lower layer 24 is placed above the base layer 22 by performing a lower layer forming step S1, which will be described later. In the embodiment illustrated in FIG. 3 , the base layer 22 is formed on a foundation 20 having a buildup surface 21. In the base layer forming step S3, the cementitious material M is discharged from the nozzle 2 by increasing or decreasing the discharge rate of the cementitious material M while moving the nozzle 2 forward. Therefore, the upper surface 23 of the base layer 22 has unevenness alternating along the front-rear direction D1.

[0020] An example of a specific flow of the base layer forming step S3 will be described. Fig. 4 is an example of a flowchart of the base layer forming step S3. Fig. 5 is a diagram for explaining an example of the first layer forming step S3a shown in Fig. 4. Fig. 6 is a diagram for explaining an example of the second layer forming step S3b shown in Fig. 4.

[0021] As illustrated in Fig. 4, the base layer forming step S3 includes a first layer forming step S3a and a second layer forming step S3b. As illustrated in Fig. 5, the first layer forming step S3a involves discharging cementitious material M from the nozzle 2 of the additive manufacturing machine 1 onto the build-up surface 21 to form a first layer 27A having a plurality of peaks 29 spaced apart from one another. Specifically, the nozzle 2 is moved forward while alternately discharging and not discharging the cementitious material M.

[0022] As illustrated in Fig. 6, in the second layer formation step S3b, cementitious material M is continuously discharged from the nozzle 2 of the additive manufacturing machine 1 onto the upper surface of the first layer 27A to form a second layer 27B having irregularities. Specifically, the nozzle 2 is moved forward while keeping the discharge rate of the cementitious material M constant. As a result, the upper surface of the second layer 27 has irregularities. Then, a base layer 22 composed of the first layer 27A and the second layer 27B is formed on the lamination surface 21.

[0023] 7 is a diagram illustrating an example of a lower layer forming step S1 according to one embodiment. As shown in FIG. 7, in the lower layer forming step S1, a cement-based material M is discharged from a nozzle 2 of an additive manufacturing machine 1 to form a lower layer 24 including both a plurality of recesses 26 and a plurality of protrusions 28 on an upper surface 25.

[0024] In one embodiment, the lower layer forming step S1 involves alternately moving the nozzle 2 upward and downward while discharging the cementitious material M from the nozzle 2 onto the upper surface 23 of the base layer 22. In the lower layer forming step S1, for example, the cementitious material M is discharged from the nozzle 2 at a constant discharge rate so that the height of the lower layer 24 is approximately 1 cm. Therefore, as shown in FIG. 4 , the lower layer 24 is layered on the upper surface 23 of the base layer 22 so as to have a corrugated shape. Furthermore, the upper surface 25 of the lower layer 24 has alternating recesses 26 and protrusions 28 formed along the front-to-back direction D1. In one embodiment, if an imaginary line located midway between the highest point P1 and the lowest point P2 of the upper surface 25 of the lower layer 24 in the up-down direction D2 is defined as an intermediate line LA, the portions of the upper surface 25 of the lower layer 24 located below the intermediate line LA are the recesses 26, and the portions located above the intermediate line LA are the protrusions 28. The space formed by the recessed portion of the upper surface 23 of the base layer 22 is filled with a cement-based material M.

[0025] The recesses 26 and protrusions 28 of the lower layer 24 are obtained by removing unintentional irregularities, such as irregularities caused by mixed materials. As shown in FIG. 7, the height of the lower layer 24 is h, the depth of each of the multiple recesses 26 is X1(X), and the height of each of the multiple protrusions 28 is X2(X). X1 is the length in the vertical direction D2 from the intermediate line LA to the bottom surface of the recess 26 (position P2). X2 is the length in the vertical direction D2 from the intermediate line LA to the top surface of the protrusion 28 (position P1). In one embodiment, X1 / h≧0.4 is satisfied. In another embodiment, X2 / h≧0.4 is satisfied.

[0026] Note that the plurality of recesses 26 may have different depths. Similarly, the plurality of protrusions 28 may have different heights. In some embodiments, when the height of the lower layer 24 is h and the depth of the shallowest recess 26 among the plurality of recesses 26 is X1, X1 / h≧0.4 is satisfied. In some embodiments, when the height of the lower layer 24 is h and the height of the shortest protrusion 28 among the plurality of protrusions 28 is X2, X2 / h≧0.4 is satisfied.

[0027] 8 is a diagram illustrating an example of an upper layer forming step S2 according to one embodiment. As shown in FIG. 8, in the upper layer forming step S2, cementitious material M is discharged from nozzle 2 of additive manufacturing machine 1 to form upper layer 30 on lower surface 31, which includes both a plurality of upper convex portions 32 that engage with concave portions 26 and a plurality of upper concave portions 34 that engage with convex portions 28. Upper layer 30 is placed on upper surface 25 of lower layer 24. Note that upper layer forming step S2 may be performed after waiting for a predetermined time to harden lower layer 24, or may be performed before lower layer 24 hardens (while cementitious material M of lower layer 24 is still fresh).

[0028] In one embodiment, the upper layer forming step S2 involves alternately moving the nozzle 2 upward and downward while discharging the cementitious material M from the nozzle 2 onto the upper surface 25 of the lower layer 24. In the upper layer forming step S2, the cementitious material M is discharged from the nozzle 2 at a constant discharge rate so that the height of the upper layer 30 is approximately 1 cm. Therefore, as shown in FIG. 8 , the upper layer 30 is layered on the upper surface 25 of the lower layer 24 so as to have a corrugated shape. Furthermore, upper convex portions 32 and upper concave portions 34 are formed alternately on the lower surface 31 of the upper layer 30 along the front-rear direction D1. In one embodiment, the portions of the lower surface 31 of the upper layer 30 that are located below the intermediate line LA are the upper convex portions 32, and the portions that are located above the intermediate line LA are the upper concave portions 34.

[0029] Fig. 9 is an enlarged view of the lower layer 24 and the upper layer 30 according to one embodiment. As shown in Fig. 9, the shear key portion 40 is defined by the convex portion 28 of the lower layer 24, the upper concave portion 34 of the upper layer 30, the front portion of the concave portion 26 (rear concave portion 26A) continuing to the rear of the convex portion 28, the front portion of the upper convex portion 32 (rear upper convex portion 32A) continuing to the rear of the upper concave portion 34, the rear portion of the concave portion 26 (front concave portion 26B) continuing to the front of the convex portion 28, and the rear portion of the upper convex portion 32 (front upper convex portion 32B) continuing to the front of the upper concave portion 34.

[0030] In one embodiment, the coefficient of friction of the upper surface 25 of the lower layer 24 is V0, the vertical compressive stress acting on the upper surface 25 of the lower layer 24 is σ, the horizontal projection area of ​​the shear key portion 40 is A, the bearing capacity of the shear key portion 40 in the fore-and-aft direction D1 is Q1, and the shear capacity of the shear key portion 40 in the fore-and-aft direction D1 is Q2, so that A·V0·σ>min(Q1, Q2) is satisfied. The horizontal projection area A is the length in the fore-and-aft direction D1 from the rear end P3 to the front end P4 of the shear key portion 40 multiplied by the width of the shear key portion 40 (lower layer 24). The rear end P3 and the front end P4 of the shear key portion 40 are each located at the lowest point of the shear key portion 40.

[0031] Q1 is calculated, for example, by Q1 = a·fc·x·w. Here, a is the bearing coefficient and is 1.0 or more and 1.2 or less. fc is the compressive strength of the convex portion 28 of the lower layer 24 and is a pre-measured value. x is the stack height of the shear key portion 40, which is the distance from the apex P5 to the rear end P3 of the shear key portion 40 in the vertical direction D2. In one embodiment, x = X1 + X2. w is the stack width of the shear key portion 40, that is, the width of the lower layer 24.

[0032] Q2 is calculated, for example, by 1.5 √(fc) b w. Here, b is the length of the base of the shear key portion 40. b is the minimum horizontal projection distance from the apex to the bottom of the shear key portion 40 in the fore-and-aft direction D1. In one embodiment, b is the length in the fore-and-aft direction D1 from the apex P5 to the front end P4 of the shear key portion 40. fc and w have already been explained and will not be described here.

[0033] The following describes the effects and advantages of a method for forming a molded object according to an embodiment. According to the embodiment, the upper convex portion 32 of the upper layer 30 is engaged with the concave portion 26 of the lower layer 24, and the upper concave portion 34 of the upper layer 30 is engaged with the convex portion 28 of the lower layer 24. Therefore, even if a force acts on the molded object 100 in the front-rear direction D1, the upper layer 30 is prevented from shifting relative to the lower layer 24. In other words, the method for forming a molded object according to the embodiment can provide a molded object 100 that has increased strength against a force acting in the front-rear direction D1. Furthermore, the method for forming a molded object according to the embodiment improves the layering process of the cement-based material M to increase the strength of the molded object 100 against a force acting in the front-rear direction D1, thereby eliminating the need for a reinforcing material insertion process, as described in, for example, Patent Document 1. Therefore, the method for forming a molded object according to the embodiment can reduce the number of steps required.

[0034] According to one embodiment, X1 / h ≥ 0.4 and X2 / h ≥ 0.4 are both satisfied, and therefore it is possible to form the convex portions 28 and the concave portions 26 that can prevent the upper layer 30 from shifting relative to the lower layer 24 when a force is applied to the object 100 in the front-rear direction D1. According to one embodiment, A·V0·σ>min(Q1, Q2) is satisfied, and therefore it is possible to provide the object 100 that can prevent the upper layer 30 from shifting relative to the lower layer 24 when a force is applied to the object 100 in the front-rear direction D1.

[0035] According to one embodiment, in the lower layer forming step S1, the nozzle 2 is moved alternately upward and downward while the cementitious material M is being discharged from the nozzle 2 onto the upper surface 23 of the base layer 22, so that the lower layer 24 including the recessed portion 26 and the protruding portion 28 can be easily formed. Similarly, in the upper layer forming step S2, the nozzle 2 is moved alternately upward and downward while the cementitious material M is being discharged from the nozzle 2 onto the upper surface 25 of the lower layer 24, so that the upper layer 30 including the upper protruding portion 32 and the upper recessed portion 34 can be easily formed.

[0036] In one embodiment, the upper surface 25 of the lower layer 24 has the recesses 26 and the protrusions 28, and the lower surface 31 of the upper layer 30 has the upper protrusions 32 and the upper recesses 34. However, the present disclosure is not limited to this embodiment. FIGS. 10A and 10B are schematic diagrams illustrating the configurations of the lower layer 24 and the upper layer 30 according to some embodiments. In the embodiment illustrated in FIG. 10A, the upper surface 25 of the lower layer 24 has the recesses 26 but does not have the protrusions 28. The lower surface 31 of the upper layer 30 has the upper recesses 34 but does not have the upper protrusions 32. In the embodiment illustrated in FIG. 10B, the upper surface 25 of the lower layer 24 has the protrusions 28 but does not have the recesses 26. The lower surface 31 of the upper layer 30 has the upper protrusions 32 but does not have the upper recesses 34.

[0037] In one embodiment, the lower layer 24 is laminated on the base layer 22, but the present disclosure is not limited to this form. In some embodiments, the lower layer 24 is formed as the base layer 22. In some embodiments, the lower layer 24 is formed above the base layer 22 and spaced apart from the base layer 22. There may be another layer between the lower layer 24 and the base layer 22, formed by ejecting the cementitious material M from the nozzle 2.

[0038] The configuration of a nozzle 2 applied to a layered manufacturing machine 1 according to the present disclosure will be described. FIGS. 11A and 11B are diagrams each schematically illustrating the configuration of a nozzle 2 according to a first modified example. FIG. 11A is a diagram of the nozzle 2 as viewed from below. FIG. 11B is a diagram of the nozzle 2 as viewed from behind. As illustrated in FIG. 11A, the nozzle 2 includes a tip portion 82 that defines a discharge port 80 (opening 2a) that opens downward. In the embodiment illustrated in FIG. 11A, the tip portion 82 includes a front wall portion 82A, a rear wall portion 82B, a left wall portion 82C, and a right wall portion 82D. The discharge port 80 is surrounded by the front wall portion 82A, the rear wall portion 82B, the left wall portion 82C, and the right wall portion 82D, and has a rectangular cross-sectional shape. The shorter side of this cross-sectional shape is in the front-to-rear direction D1. 11B, a notch 83 is formed in a rear wall portion 82B, which is a rear portion of the tip portion 82 that surrounds the discharge port 80 from the rear side in the front-rear direction D1. The diameter of the notch 83 increases downward, and the notch 83 has, for example, a semicircular shape. The cross-sectional shape of the discharge port 80 is not limited to a rectangular shape and may be, for example, a circular shape. The shape of the notch 83 is not limited to a semicircular shape and may be, for example, a triangular shape.

[0039] 11C is a diagram schematically illustrating the configuration of the lower layer 24 and the upper layer 30 deposited by the nozzle 2 according to the first modified example. As shown in FIG. 11C, the cementitious material M (lower layer 24 and upper layer 30) discharged from the nozzle 2 according to the first modified example includes a protrusion 84 that protrudes from a part of the upper surface in the left-right direction D3. Therefore, even if a force acts on the shaped object 100 in the left-right direction D3, the upper layer 30 is prevented from shifting relative to the lower layer 24.

[0040] Note that the present disclosure does not limit the configuration for preventing the upper layer 30 from shifting relative to the lower layer 24 to the raised portion 84. FIG. 11D is a diagram schematically illustrating the configuration of a nozzle 2 according to a second modified example, viewed from the rear. FIG. 11E is a diagram schematically illustrating the configuration of the lower layer 24 and the upper layer 30 deposited by the nozzle 2 according to the second modified example. In the configuration illustrated in FIG. 11D, a notch 83 is formed in the rear wall portion 82B so that a portion 85 of the remaining portion is semicircular. The portion 85 of the remaining portion is not limited to a semicircular shape and may be, for example, triangular. According to the nozzle 2 according to the second modified example, as shown in FIG. 11E, the cementitious material M (the lower layer 24 and the upper layer 30) discharged from the nozzle 2 includes a sunken portion 86 that is recessed from a portion of the top surface 25 of the lower layer 24 in the left-right direction D3. Therefore, even if a force acts on the shaped object 100 in the left-right direction D3, the upper layer 30 is prevented from shifting relative to the lower layer 24.

[0041] 12A and 12B are diagrams each schematically illustrating a configuration of a nozzle 2 according to a third modified example. FIG. 12A is a diagram illustrating the nozzle 2 as viewed from the rear. FIG. 12B is a diagram illustrating the nozzle 2 as viewed from the right. As illustrated in FIG. 12A, the nozzle 2 includes a tip portion 88 in which an outlet 87 (opening 2a) opening to the rear in the front-rear direction D1 is formed. In the embodiment illustrated in FIG. 12A, the tip portion 88 includes a front wall portion 88A, a rear wall portion 88B, a left wall portion 88C, and a right wall portion 88D. The outlet portion of the flow path of the nozzle 2 is defined by the front wall portion 88A, the rear wall portion 88B, the left wall portion 88C, and the right wall portion 88D. The outlet 87 is formed in the rear wall portion 88B. Furthermore, as illustrated in FIG. 12B, a corner 89 of the front wall portion 88A, which is the front portion of the tip portion 88 on the front side in the front-rear direction D1, is chamfered. The corner 89 is a portion that extends forward as it moves upward from the lower end of the front wall portion 88A. The corner 89 may extend linearly or curvedly. According to the nozzle 2 of the third modified example, when the nozzle 2 discharges the cementitious material M onto the lower layer 24, damage to the lower layer 24 by the tip 88 of the nozzle 2 can be suppressed.

[0042] FIG. 13 is a perspective view schematically illustrating the configuration of a nozzle 2 according to a fourth modified example. As illustrated in FIG. 13, the nozzle 2 includes a tip portion 91 having a discharge port 90 (opening 2a) opening to one side in the left-right direction D3, and a cylindrical protrusion 92 protruding from the tip portion 91. The protrusion 92 has a discharge passage 95 formed therein, the discharge port 93 of which communicates with the discharge port 90 and the outlet 94 of which opens to at least one of the rear and the downward direction. In the configuration illustrated in FIG. 13, the discharge port 90 opens to the left, and the outlet 94 of the protrusion 92 opens to both the rear and the downward direction. The nozzle 2 according to the fourth modified example can suppress damage to the lower layer 24 caused by the tip portion 88 of the nozzle 2 when the nozzle 2 discharges the cementitious material M onto the lower layer 24. Furthermore, the protrusion 92 can shape the upper and left surfaces of the cementitious material M discharged from the opening 2a.

[0043] FIG. 14 is a perspective view schematically illustrating the configuration of a nozzle 2 according to a fifth modified example. The nozzle 2 includes a cylindrical nozzle body 41 extending in the up-down direction D2 and a cylindrical trowel portion 42 extending rearward from the lower end of the nozzle body 41. The nozzle body 41 and the trowel portion 42 are each configured to allow the flow of cement-based material M. An opening 2a of the nozzle 2 is formed at the lower end of the nozzle body 41. If the horizontal direction perpendicular to the front-rear direction D1 is defined as the left-right direction D3, in the configuration illustrated in FIG. 14, the trowel portion 42 has an upper wall 44, a left wall 46 extending downward from the left end of the upper wall 44, and a right wall 48 extending downward from the right end of the upper wall 44. In other words, the trowel portion 42 defines an internal space 43 defined by the upper wall 44, the left wall 46, and the right wall 48. The upper wall 44 is formed with an upper wall protrusion 45 that protrudes into the internal space 43 .

[0044] According to the configuration exemplified for the nozzle 2 of the fifth modified example, the cementitious material M discharged from the opening 2a can be shaped by the trowel portion 42. Furthermore, since the upper wall 44 is formed with the upper wall protrusion 45, even if a force acts on the shaped object 100 in the left-right direction D3, the upper layer 30 is prevented from shifting relative to the lower layer 24.

[0045] FIG. 15 is a perspective view schematically illustrating the configuration of a nozzle 2 according to some embodiments. FIG. 16 is a perspective view illustrating an example of a molded object 100 formed by performing a molded object forming method according to an embodiment using the nozzle 2 illustrated in FIG. 15. The nozzle 2 illustrated in FIG. 15 differs from the nozzle 2 illustrated in FIG. 14 in that an upper wall protrusion 45 protrudes upward. Furthermore, the upper wall protrusion 45 has a triangular cross section when cut along the vertical direction D2. Therefore, as illustrated in FIG. 16, when the above-described molded object forming method according to an embodiment (lower layer forming step S1, upper layer forming step S2, and base layer forming step S3) is performed using the nozzle 2 illustrated in FIG. 15, a molded object 100 is formed.

[0046] FIG. 17 is a flowchart showing a method for forming an object according to some embodiments. FIG. 18 is a diagram illustrating an example of the laying-on-side step S4. In some embodiments, as illustrated in FIG. 18, the method for forming an object further includes a laying-on-side step S4 that is performed after the upper-layer forming step S2. In the laying-on-side step S4, both the hardened lower layer 24 and the hardened upper layer 30 are laid on their sides by waiting for a predetermined time. Then, as illustrated in FIG. 18, a model 100, such as a floor, is formed.

[0047] 19 is a flowchart showing a method for forming an object according to another embodiment. As shown in FIG. 19, the method for forming an object includes a lower layer forming step S11 and an upper layer forming step S12. In another embodiment, the method for forming an object further includes a base layer forming step S13, and the base layer forming step S13, the lower layer forming step S11, and the upper layer forming step S12 are performed in this order.

[0048] 20 is a diagram illustrating an example of a base layer forming step S13 according to another embodiment. As shown in Fig. 20, in the base layer forming step S13, cementitious material M is discharged from the nozzle 2 of the layered manufacturing machine 1 to form a base layer 52 on the foundation 20. In another embodiment, in the base layer forming step S3, the cementitious material M is discharged from the nozzle 2 by increasing the discharge rate of the cementitious material M while moving the nozzle 2 forward. Therefore, the upper surface 53 of the base layer 52 is inclined with respect to the front-rear direction D1.

[0049] 21 is a diagram illustrating an example of a lower layer forming step S11 according to another embodiment. As shown in Fig. 21, in the lower layer forming step S11, a cement-based material M is discharged from a nozzle 2 of the layered manufacturing machine 1 to form a lower layer 54 whose upper surface 55 is inclined at a predetermined angle θ with respect to the front-rear direction D1.

[0050] In another embodiment, in the lower layer forming step S1, the nozzle 2 is moved obliquely from below to above while discharging the cementitious material M from the nozzle 2 onto the upper surface 53 of the base layer 52. In the lower layer forming step S11, the cementitious material M is discharged from the nozzle 2 at a constant discharge rate. Therefore, as shown in FIG. 21 , the lower layer 54 is stacked on the upper surface 53 of the base layer 52 so as to have a linear shape. Furthermore, the upper surface 55 of the lower layer 54 is inclined at a predetermined angle θ with respect to the front-to-rear direction D1. The angle θ is the smaller of the angles formed by a first imaginary line 57 extending the linearly extending upper surface 55 in the front-to-rear direction D1 and a second imaginary line 59 extending in the front-to-rear direction D1. In one embodiment, the predetermined angle θ is in the range of 1 degree or more and less than 90 degrees. More preferably, the predetermined angle θ is in the range of 15 degrees or more and less than 90 degrees.

[0051] 22 is a diagram illustrating an example of an upper layer forming step S12 according to another embodiment. As shown in FIG. 22, in the upper layer forming step S12, the cementitious material M is discharged from the nozzle 2 of the layered manufacturing machine 1 to form an upper layer 56 that is placed on an upper surface 55 of the lower layer 54.

[0052] In another embodiment, the upper layer forming step S12 involves discharging the cementitious material M from the nozzle 2 onto the upper surface 55 of the lower layer 54 by moving the nozzle 2 obliquely from below to above along the upper surface 55 of the lower layer 54. In the upper layer forming step S12, the cementitious material M is discharged from the nozzle 2 at a constant discharge rate. Therefore, as shown in FIG. 15 , the upper layer 56 is laminated on the upper surface 55 of the lower layer 54 so as to have a linear shape. Note that the upper layer forming step S12 may be performed after waiting for a predetermined time to harden the lower layer 54, or may be performed before the lower layer 54 hardens (while the cementitious material M of the lower layer 54 is still fresh).

[0053] The following describes the effects and advantages of a method for forming a model according to another embodiment. According to this embodiment, when a force acts on the model 100 in the front-to-rear direction D1, the strength of the model 100 against the force acting in the front-to-rear direction D1 can be increased compared to when the upper surface 55 of the lower layer 54 is at an angle smaller than a predetermined angle θ. Furthermore, the method for forming a model according to this embodiment improves the lamination process of the cement-based material M in order to increase the strength of the model 100 against the force acting in the front-to-rear direction D1, and does not require the insertion process of a reinforcing material as described in Patent Document 1, for example. Therefore, the method for forming a model according to this embodiment can suppress an increase in the number of steps.

[0054] According to another embodiment, the predetermined angle θ is in the range of 20 degrees or more and less than 90 degrees, and therefore it is possible to form an upper surface 55 of the lower layer 54 that can prevent the upper layer 56 from shifting relative to the lower layer 54 when a force acts on the object 100 in the front-to-rear direction D1. The object 100 (the second object 100b and the fourth object 100d shown in FIG. 1 ) formed by the object formation method according to another embodiment is used for structures in which oblique compressive stress acts, such as buttresses.

[0055] Fig. 23 is a flowchart showing a method for forming an object according to yet another embodiment. As shown in Fig. 23, the method for forming an object includes a lower layer forming step S21 and an upper layer forming step S22.

[0056] FIG. 24 is a diagram illustrating an example of a lower layer forming step S21 according to yet another embodiment. As shown in FIG. 24 , in the lower layer forming step S21, cementitious material M is discharged from the nozzle 2 of the additive manufacturing machine 1 to form a lower layer 60 having an upper surface 61 including recesses 62 and protrusions 64. Furthermore, in this lower layer 60, a linearly extending portion 65 of the upper surface 61, excluding the recesses 62 and protrusions 64, is inclined at a predetermined angle θ with respect to the front-to-rear direction D1. The angle θ is the smaller of the angles formed by a third imaginary line 67 extending the linearly extending portion 65 of the upper surface 61 in the front-to-rear direction D1 and a fourth imaginary line 69 extending in the front-to-rear direction D1. The lower layer 60 is layered on any object; for example, it may be layered on a foundation 20 or on a layer formed by discharging cementitious material M from the nozzle 2.

[0057] 25 is a diagram illustrating an example of an upper layer forming step S22 according to yet another embodiment. As shown in Fig. 25, in the upper layer forming step S22, cementitious material M is discharged from the nozzle 2 of the additive manufacturing machine 1 to form an upper layer 70 that includes upper convex portions 72 that engage with concave portions 62 and upper concave portions 74 that engage with convex portions 64 on its lower surface 71 and is placed on the upper surface 61 of the lower layer 60. Note that the upper layer forming step S22 may be performed after the lower layer 60 has hardened by waiting for a predetermined time, or may be performed before the lower layer 60 hardens (while the cementitious material M of the lower layer 60 is still fresh).

[0058] The effects and advantages of a method for forming a structure according to yet another embodiment will be described. According to yet another embodiment, the upper convex portions 72 of the upper layer 70 are engaged with the concave portions 62 of the lower layer 60, and the upper concave portions 74 of the upper layer 70 are engaged with the convex portions 64 of the lower layer 60. Therefore, even if a force acts on the structure 100 in the front-to-rear direction D1, the upper layer 70 is prevented from shifting relative to the lower layer 60. In other words, the method for forming a structure according to yet another embodiment can provide a structure 100 that has increased strength against a force acting in the front-to-rear direction D1. Furthermore, according to yet another embodiment, when a force acts on the structure 100 in the front-to-rear direction D1, the strength against the force acting in the front-to-rear direction D1 can be increased compared to when the linearly extending portion 65 of the upper surface 61 of the lower layer 60 is angled at an angle smaller than a predetermined angle θ. Furthermore, in a method for forming a molded object according to yet another embodiment, the lamination step of the cementitious material M is devised in order to increase the strength against forces acting in the front-rear direction D1, and the method does not require the step of inserting a reinforcing material as described in Patent Document 1, for example. Therefore, the method for forming a molded object according to yet another embodiment can suppress an increase in the number of steps.

[0059] 23 further includes a base layer forming step S23 that is performed before the lower layer forming step S21. In the base layer forming step S23, a cement-based material M is ejected from a nozzle 2 onto the layering surface 21 to form a base layer 120 whose upper surface is inclined and has projections and depressions.

[0060] Fig. 26 is an example of a flowchart of the base layer forming step S23. Fig. 27 is a diagram for explaining an example of the oblique layer forming step S23a shown in Fig. 26. Fig. 28 is a diagram for explaining an example of the first layer forming step S23b shown in Fig. 26. Fig. 29 is a diagram for explaining an example of the second layer forming step S23c shown in Fig. 26.

[0061] As illustrated in Fig. 26, the base layer forming step S23 includes an inclined layer forming step S23a, a first layer forming step S23b, and a second layer forming step S23c. As illustrated in Fig. 27, the inclined layer forming step S23a involves discharging cementitious material M from the nozzle 2 onto the layering surface 21 to form an inclined layer 120A including an inclined surface 121. Specifically, the nozzle 2 is moved forward while increasing the amount of cementitious material M discharged. The first layer forming step S23b involves discharging cementitious material M from the nozzle 2 onto the inclined surface 121 of the inclined layer 120A to form a first layer 120B having a plurality of peaks 122 spaced apart from one another. Specifically, the nozzle 2 is moved forward while alternately discharging and not discharging cementitious material M onto the inclined surface 121. In the second layer forming step S23c, cement material M is continuously discharged from the nozzle 2 onto the upper surface of the first layer 120B to form the second layer 120C having an uneven surface. Specifically, the nozzle 2 is moved forward while maintaining a constant discharge rate of the cement material M. As a result, the upper surface of the second layer 120C has an uneven surface. Then, a base layer 120 composed of the inclined layer 120A, the first layer 120B, and the second layer 120C is formed on the stacking surface 21.

[0062] In the embodiment described above, the additive manufacturing machine 1 discharges the cementitious material M from above downward, but the present disclosure is not limited to this embodiment. The model 100 may be formed by the additive manufacturing machine 1 discharging and stacking the cementitious material M from one side to the other in the horizontal direction (for example, from left to right in the width direction of the building).

[0063] When the cementitious material M is discharged horizontally as described above, the method for forming an object 100 by layering the cementitious material M with the additive manufacturing machine 1 includes a first layer formation step of discharging the cementitious material M from the additive manufacturing machine 1 to form a first layer that includes at least one of a recess and a protrusion on the surface of the first layer on the nozzle 2 side of the additive manufacturing machine 1, and a second layer formation step of discharging the cementitious material M from the additive manufacturing machine 1 to form a second layer that includes at least one of a second-layer side protrusion that engages with the recess and a second-layer side recess that engages with the protrusion on the surface of the first layer, and is placed on the surface of the first layer.

[0064] When the cementitious material M is discharged horizontally as described above, the method for forming an object 100 by layering the cementitious material M with the additive manufacturing machine 1 includes a first layer formation step in which the cementitious material M is discharged from the additive manufacturing machine 1 to form a first layer in which the surface of the first layer on the nozzle 2 side of the additive manufacturing machine 1 is inclined at a predetermined angle relative to the front-to-back direction, and a second layer formation step in which the cementitious material M is discharged from the additive manufacturing machine 1 to form a second layer that is placed on the surface of the first layer.

[0065] When the cementitious material M is discharged horizontally as described above, the method for forming an object 100 by layering the cementitious material M with the additive manufacturing machine 1 includes a first layer formation step of discharging the cementitious material M from the additive manufacturing machine 1 to form a first layer in which the surface of the first layer on the nozzle 2 side of the additive manufacturing machine 1 includes at least one of a concave portion and a convex portion, and the surface of the first layer is inclined at a predetermined angle with respect to the front-to-rear direction, and a second layer formation step of discharging the cementitious material M from the additive manufacturing machine 1 to form a second layer in which the surface on the first layer side includes at least one of an upper convex portion that engages with the concave portion and an upper concave portion that engages with the convex portion, and is placed on the surface of the first layer.

[0066] The contents described in each of the above embodiments can be understood, for example, as follows.

[0067] [1] A method for forming a structure according to the present disclosure includes: A method for manufacturing a model (100) by layering a cementitious material (M) using a layer-by-layer manufacturing machine (1), comprising: a lower layer forming step (S1) in which the cementitious material is discharged from the additive manufacturing machine to form a lower layer (24) having an upper surface (25) including at least one of a recessed portion (26) and a protruding portion (28); and an upper layer formation step (S2) in which the cement-based material is discharged from the additive manufacturing machine to form an upper layer (30) that includes on its lower surface (31) at least one of an upper convex portion (32) that engages with the concave portion and an upper concave portion (34) that engages with the convex portion, and that is placed on the upper surface of the lower layer.

[0068] According to the method described in [1] above, at least one of engaging an upper convex portion of an upper layer with a concave portion of a lower layer and engaging an upper concave portion of an upper layer with a convex portion of a lower layer is achieved. Therefore, even if a force acts on the object in the front-to-rear direction, the upper layer is prevented from shifting relative to the lower layer. In other words, the method for forming a molded object according to the present disclosure can provide a molded object with increased strength against forces acting in the front-to-rear direction. Furthermore, the method for forming a molded object according to the present disclosure utilizes a specially designed lamination process for cement-based materials to increase strength against forces acting in the front-to-rear direction, thereby eliminating the need for a reinforcing material insertion process, as described in, for example, Patent Document 1. Therefore, the method for forming a molded object according to the present disclosure can reduce the number of steps required.

[0069] [2] A method for forming a structure according to the present disclosure includes: A method for manufacturing a model (100) by layering a cementitious material (M) using a layer-by-layer manufacturing machine (1), comprising: a lower layer forming step (S11) in which the cementitious material is discharged from the additive manufacturing machine to form a lower layer (54) whose upper surface (55) is inclined at a predetermined angle (θ) with respect to a front-to-rear direction (D1); and an upper layer forming step (S12) of discharging the cementitious material from the additive manufacturing machine to form an upper layer (56) to be placed on the upper surface of the lower layer.

[0070] According to the method described in [2] above, when a force acts on a shaped object in the front-to-rear direction, the strength of the shaped object against the force acting in the front-to-rear direction can be increased compared to when the upper surface of the lower layer is inclined at an angle less than a predetermined angle. Furthermore, the shaped object forming method according to the present disclosure is an improved method for laminating cement-based materials in order to increase the strength of the shaped object against the force acting in the front-to-rear direction, and does not require the step of inserting a reinforcing material as described in, for example, Patent Document 1. Therefore, the shaped object forming method according to the present disclosure can suppress an increase in the number of steps.

[0071] [3] A method for forming a structure according to the present disclosure includes: A method for manufacturing a model (100) by layering a cementitious material (M) using a layer-by-layer manufacturing machine (1), comprising: a lower layer forming step (S21) in which the cementitious material is discharged from the additive manufacturing machine to form a lower layer (60) having an upper surface (61) including at least one of a recessed portion (62) and a protruding portion (64), and the upper surface is inclined at a predetermined angle (θ) with respect to a front-to-rear direction (D1); and an upper layer forming step (S22) in which the cement-based material is discharged from the additive manufacturing machine to form an upper layer (70) that is placed on the upper surface of the lower layer and that includes on its lower surface (71) at least one of an upper convex portion (72) that engages with the concave portion and an upper concave portion (74) that engages with the convex portion.

[0072] According to the method described in [3] above, at least one of engaging an upper convex portion of the upper layer with a concave portion of the lower layer and engaging an upper concave portion of the upper layer with a convex portion of the lower layer is achieved. Therefore, even if a force acts on the object in the front-to-rear direction, the upper layer is prevented from shifting relative to the lower layer. In other words, the method for forming a molded object according to the present disclosure can provide a molded object with increased strength against a force acting in the front-to-rear direction. Furthermore, when a force acts on the object in the front-to-rear direction, the strength against the force acting in the front-to-rear direction can be increased compared to when the upper surface of the lower layer is inclined at an angle less than a predetermined angle. Furthermore, the method for forming a molded object according to the present disclosure devise a layering process for cement-based materials to increase the strength against a force acting in the front-to-rear direction, and does not require the insertion of a reinforcing material as described in, for example, Patent Document 1. Therefore, the method for forming a molded object according to the present disclosure can reduce the number of steps required.

[0073] [4] In some embodiments, in the method according to [1] or [3] above, When the height of the lower layer is h and the height of the convex portion or the depth of the concave portion is X, the relationship X / h≧0.4 is satisfied.

[0074] According to the method described in [4] above, it is possible to form convex or concave portions that can prevent the upper layer from shifting relative to the lower layer when a force is applied to the shaped object in the forward and backward directions.

[0075] [5] In some embodiments, in the method according to [1] or [3] above, Let V0 be the coefficient of friction of the upper surface of the lower layer, σ be the vertical compressive stress acting on the upper surface of the lower layer, A be the horizontal projection area of ​​the shear key portion (40) defined by at least one of the recess and the upper convex portion and the convex portion and the upper recess, Q1 be the bearing strength of the shear key portion in the front-to-rear direction (D1), and Q2 be the shear strength of the shear key portion in the front-to-rear direction (D1), A·V0·σ>min(Q1, Q2) is satisfied.

[0076] According to the method described in [5] above, it is possible to provide a shaped object that can prevent the upper layer from shifting relative to the lower layer when a force acts on the shaped object in the forward / backward direction.

[0077] [6] In some embodiments, in the method according to [1] or [3] above, The layered manufacturing machine includes a nozzle (2) that discharges the cementitious material, and a movement mechanism (4) that moves the nozzle along a vertical direction (D2), The lower layer forming step includes alternately moving the nozzle upward and downward while discharging the cementitious material from the nozzle; The upper layer forming step includes moving the nozzle upward or downward while discharging the cementitious material from the nozzle.

[0078] According to the method described in [6] above, it is possible to easily form a lower layer including recesses and protrusions and an upper layer including upper protrusions and upper recesses.

[0079] [7] In some embodiments, in the method according to [2] above, the additive manufacturing machine includes a nozzle that discharges the cementitious material and a movement mechanism that moves the nozzle; the lower layer forming step includes moving the nozzle obliquely from below to above while discharging the cement-based material from the nozzle; The upper layer forming step includes moving the nozzle obliquely from below to above along the upper surface of the lower layer while discharging the cement-based material from the nozzle.

[0080] According to the method described in [7] above, it is possible to easily form a sloping lower layer and a sloping upper layer.

[0081] [8] In some embodiments, in the method according to [6] above, The nozzle includes a tip (82) defining a downwardly opening discharge port (80); A notch (83) is formed in the rear portion of the tip portion surrounding the discharge port from the rear side in the front-rear direction.

[0082] According to the method described in [8] above, by forming a notch in the rear part of the nozzle tip, the cementitious material (lower and upper layers) discharged from the nozzle includes a protruding portion protruding from a part of the upper surface and a settling portion settling from a part of the upper surface, which prevents the upper layer from shifting relative to the lower layer even if a force acts on the model in the lateral direction.

[0083] [9] In some embodiments, in the method according to [6] above, The nozzle includes a tip portion (88) having a discharge port (87) that opens to the rear side in the front-rear direction (D1), The corner (89) of the front end portion on the front side in the front-rear direction is chamfered.

[0084] According to the method described in [9] above, when the nozzle discharges the cementitious material onto the lower layer, damage to the lower layer caused by the tip of the nozzle can be suppressed.

[0085]

[10] In some embodiments, in the method according to [6] above, The nozzle has a tip (91) formed with a discharge port (90) that opens to one side in the left-right direction (D3); and a discharge part which is a cylindrical protruding part (92) protruding from the tip end and which has a discharge passage (95) formed therein, the inlet (93) of which is connected to the discharge port and the outlet (94) of which opens to at least one of the rear and the downward direction.

[0086] According to the method described in

[10] above, when the nozzle discharges the cementitious material onto the lower layer, damage to the lower layer caused by the tip of the nozzle can be suppressed.

[0087]

[11] In some embodiments, in the method according to [2] or [3] above, The predetermined angle is in the range of 20 degrees or more and less than 90 degrees.

[0088] According to the method described in

[11] above, it is possible to form an upper surface of the lower layer that can prevent the upper layer from shifting relative to the lower layer when a force acts on the shaped object in the forward / backward direction.

[0089]

[12] In some embodiments, in the method according to any one of [1] to [3] above, The method further includes a laying down step of laying down both the hardened lower layer and the hardened upper layer after the upper layer forming step.

[0090] According to the method described in

[12] above, it is possible to increase the variety of objects that can be formed, such as floors.

[0091]

[13] In some embodiments, in the method according to [1] above, a base layer forming step of discharging the cementitious material from the additive manufacturing machine onto a lamination surface on which the cementitious material is to be laminated, before the lower layer forming step, to form a base layer having an uneven upper surface on which the lower layer is placed, The base layer forming step includes: a first layer forming step of discharging the cementitious material from the additive manufacturing machine onto the lamination surface to form a first layer having a plurality of ridges spaced apart from one another; and a second layer forming step of continuously discharging the cement-based material from the additive manufacturing machine onto the upper surface of the first layer to form a second layer having irregularities.

[0092] According to the method described in

[13] above, a base layer having an uneven upper surface is formed, so that the lower and upper layers can be formed without adjusting the discharge amount of the cement-based material.

[0093]

[14] In some embodiments, in the method according to [2] or [3] above, a base layer forming step of discharging the cementitious material from the additive manufacturing machine onto a lamination surface on which the cementitious material is to be laminated, to form a base layer having an uneven upper surface, before the lower layer forming step; The base layer forming step includes: an inclined layer forming step of discharging the cement-based material from the additive manufacturing machine onto the lamination surface to form an inclined layer including an inclined surface; a first layer forming step of discharging the cementitious material from the additive manufacturing machine onto the slope of the inclined layer to form a first layer having a plurality of peaks spaced apart from one another; and a second layer forming step of continuously discharging the cement-based material from the additive manufacturing machine onto the upper surface of the first layer to form a second layer having irregularities.

[0094] According to the method described in

[14] above, a base layer having an uneven upper surface is formed, so that the lower and upper layers can be formed without adjusting the discharge amount of the cement-based material. [Explanation of symbols]

[0095] 1. Additive manufacturing machine 2 nozzles 2a aperture 4 Moving mechanism 6. Supply pump 10 Control device 20 Basics 22 Base layer 23 Top of the base layer 24 Lower layer 25 Upper surface of the lower layer 26 Recess 26A Rear recess 26B Front recess 28 Convex part 30 upper layer 31 Lower surface of upper layer 32 Upper convex part 32A Rear upper convex part 32B Front upper convex part 34 Upper recess 40 Shear key part 41 Nozzle body 42 Iron part 43 Interior Space 44 Upper Wall 45 Upper wall protrusion 46 Left Wall 48 Right wall 52 Base layer 53 Top of the base layer 54 Lower layer 55 Upper surface of lower layer 56 Upper layer 57 First Virtual Line 59 Second virtual line 60 Lower layer 61 Upper surface of the lower layer 62 recess 64 Convex part 65 parts 67 Third Virtual Line 69 4th Virtual Line 70 upper layer 71 Lower surface of upper layer 72 Upper convex part 74 Upper recess 80 outlet (first modified example, second modified example) 82 Tip portion (first modified example, second modified example) 82A Front wall 82B Rear wall 82C Left wall section 82D Right wall 83 Cutout 84 Ridge 86 Settling section 87 Outlet (Third Modification) 88 Tip (Third Variant) 88A Front wall 88B Rear wall 88C Left wall section 88D Right wall section 89 Corner 90 outlet (fourth modified example) 91 Tip (fourth variant) 92 Protrusion 93 Protrusion entrance 94 Exit of protrusion 95 Discharge path 100 Sculptures A horizontal projected area D1 Anteroposterior direction D2 Vertical direction D3 Left and right direction LA Intermediate Line M Cement-based materials S1, S11, S21 Lower layer formation steps S2, S12, S22 Upper layer formation steps S3, S13 Substrate formation step

Claims

1. A method for manufacturing a molded object by layering a cement-based material using a layer-by-layer manufacturing machine, comprising the steps of: a lower layer forming step of discharging the cementitious material from the additive manufacturing machine to form a lower layer having at least one of a recessed portion and a protruding portion on an upper surface thereof; an upper layer forming step of discharging the cementitious material from the additive manufacturing machine to form an upper layer that includes, on its lower surface, at least one of an upper convex portion that engages with the concave portion and an upper concave portion that engages with the convex portion, and is placed on the upper surface of the lower layer; Modeling method.

2. A method for manufacturing a molded object by layering a cement-based material using a layer-by-layer manufacturing machine, comprising the steps of: a lower layer forming step of discharging the cementitious material from the additive manufacturing machine to form a lower layer whose upper surface is inclined at a predetermined angle with respect to the front-to-rear direction; and an upper layer forming step of discharging the cementitious material from the additive manufacturing machine to form an upper layer that is placed on the upper surface of the lower layer. Modeling method.

3. A method for manufacturing a molded object by layering a cement-based material using a layer-by-layer manufacturing machine, comprising the steps of: a lower layer forming step of discharging the cementitious material from the additive manufacturing machine to form a lower layer having an upper surface that includes at least one of a recessed portion and a protruding portion, and the upper surface of the lower layer is inclined at a predetermined angle with respect to a front-to-rear direction; an upper layer forming step of discharging the cementitious material from the additive manufacturing machine to form an upper layer that includes, on its lower surface, at least one of an upper convex portion that engages with the concave portion and an upper concave portion that engages with the convex portion, and is placed on the upper surface of the lower layer; Modeling method.

4. When the height of the lower layer is h and the height of the convex portion or the depth of the concave portion is X, X / h≧0.4 is satisfied. The method for forming a molded object according to claim 1 or 3.

5. Let V0 be the coefficient of friction of the upper surface of the lower layer, σ be the vertical compressive stress acting on the upper surface of the lower layer, A be the horizontal projection area of ​​the shear key portion defined by at least one of the recess and the upper convex portion and the convex portion and the upper recess, Q1 be the bearing strength in the front-to-rear direction of the shear key portion, and Q2 be the shear strength in the front-to-rear direction of the shear key portion. A·V0·σ>min(Q1, Q2) is satisfied. The method for forming a molded object according to claim 1 or 3.

6. the additive manufacturing machine includes a nozzle that discharges the cementitious material, and a movement mechanism that moves the nozzle in an up-down direction; The lower layer forming step includes alternately moving the nozzle upward and downward while discharging the cementitious material from the nozzle; the upper layer forming step includes moving the nozzle upward or downward while discharging the cement-based material from the nozzle; The method for forming a molded object according to claim 1 or 3.

7. the additive manufacturing machine includes a nozzle that discharges the cementitious material and a movement mechanism that moves the nozzle; the lower layer forming step includes moving the nozzle obliquely from below to above while discharging the cement-based material from the nozzle; the upper layer forming step includes moving the nozzle obliquely from below to above along the upper surface of the lower layer while discharging the cement-based material from the nozzle; The method for forming a molded object according to claim 2 .

8. the nozzle includes a tip defining a downwardly opening discharge port; a notch is formed in a rear portion of the tip portion surrounding the discharge port from the rear side in the front-rear direction; The method for forming a shaped object according to claim 6 .

9. the nozzle includes a tip portion formed with a discharge port that opens to the rear side in the front-rear direction, The corners of the front portion of the tip portion on the front side in the front-to-rear direction are chamfered. The method for forming a shaped object according to claim 6 .

10. The nozzle has a tip end formed with a discharge port that opens to one of the left and right directions; a discharge part which is a cylindrical protrusion protruding from the tip part and has a discharge passage formed therein, the inlet of which is in communication with the discharge port and the outlet of which opens at least one of rearward and downward, The method for forming a shaped object according to claim 6 .

11. The predetermined angle is in the range of 15 degrees or more and less than 90 degrees. The method for forming a molded object according to claim 2 or 3.

12. Further provided is a step of laying down both the hardened lower layer and the hardened upper layer after the upper layer forming step. The method for forming a molded object according to claim 1 .

13. a base layer forming step of discharging the cementitious material from the additive manufacturing machine onto a lamination surface on which the cementitious material is to be laminated, before the lower layer forming step, to form a base layer having an uneven upper surface on which the lower layer is placed, The base layer forming step includes: a first layer forming step of discharging the cementitious material from the additive manufacturing machine onto the lamination surface to form a first layer having a plurality of ridges spaced apart from one another; a second layer forming step of continuously discharging the cementitious material from the additive manufacturing machine onto an upper surface of the first layer to form a second layer having concaves and convexes, The method for forming a molded object according to claim 1 .

14. a base layer forming step of discharging the cementitious material from the additive manufacturing machine onto a lamination surface on which the cementitious material is to be laminated, to form a base layer having an uneven upper surface, before the lower layer forming step; The base layer forming step includes: an inclined layer forming step of discharging the cement-based material from the additive manufacturing machine onto the lamination surface to form an inclined layer including an inclined surface; a first layer forming step of discharging the cementitious material from the additive manufacturing machine onto the slope of the inclined layer to form a first layer having a plurality of peaks spaced apart from one another; a second layer forming step of continuously discharging the cementitious material from the additive manufacturing machine onto an upper surface of the first layer to form a second layer having concaves and convexes, The method for forming a molded object according to claim 2 or 3.

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