Structure construction system and structure construction method

Abstract

This structure construction system (1) comprises: a flying body (2) that conveys an uncured building material mass (11) to an upper part of a construction site (15); and a wireless structure formation device (3) that moves along the construction site (15) and constructs a structure (ST) on the construction site (15) using the uncured building material mass (11). The wireless structure formation device (3) has a mixing-spreading part (22) including a screw (8) for mixing the uncured building material mass (11).

Description

Structural construction system and structural construction method

[0001] The present invention relates to a structural construction system and a structural construction method. This application claims priority based on Japanese Patent Application No. 2024-211142, filed on 4 December 2024, and Japanese Patent Application No. 2025-074494, filed on 28 April 2025, the contents of which are incorporated herein by reference.

[0002] Conventionally, concrete 3D printers (3DCPs) that construct large structures such as houses using three-dimensional modeling are known.

[0003] For example, Patent Document 1 (U.S. Patent Application Publication No. 2020 / 0130258) discloses the configurations of robotic arm type and gantry type 3D printers as examples of layering methods using a concrete 3D printer. In the robotic arm type, a nozzle is provided at the end of an arm of a 3D printing device that can move on the ground, and a structure is constructed by layering building materials such as mortar supplied from this nozzle. In the gantry type, a gate-shaped frame larger than the structure is installed, and layering is performed by the print head repeatedly sliding up, down, left, and right along the rail frame.

[0004] Also, as another example, for instance, in Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2020-172838), a configuration of a self-propelled 3D printer having a robotic arm that forms building materials into a standard pattern and a blowing nozzle provided at the tip of the robotic arm for blowing out the building materials is disclosed. A dummy box carried by a drone is arranged at a portion corresponding to the window part of the structure. According to the technique described in Patent Document 2, it is said that a 3D printer that is smaller and lighter than conventional 3D printers can be provided. Further, as yet another construction method, for instance, in Patent Document 3 (Japanese Patent Application Laid-Open No. 2021-521366), a configuration having a Cartesian robot that automatically ascends as the height of the structure increases is disclosed. A material supply device movable on the frame of the Cartesian robot is attached to the Cartesian robot, and materials are supplied to the material supply device by a drone as needed. According to the technique described in Patent Document 3, since the Cartesian robot ascends autonomously, various structures can be constructed without the need for an external lifting device such as a crane.

[0005] U.S. Patent Application Publication No. 2020 / 0130258, Japanese Unexamined Patent Application Publication No. 2020-172838, Japanese Patent Application Laid-Open No. 2021-521366

[0006] Incidentally, one application of such concrete 3D printers is the construction of large structures such as temporary housing in the event of a natural disaster. For this reason, it is necessary to construct the structures in a short time for the fastest possible recovery. However, in disaster-stricken areas after a disaster, the ground is prone to instability due to landslides and sinkholes, and roads may be closed, making it impossible to transport large equipment and materials. In the case of the technology described in Patent Document 1 mentioned above, a large layering device must be brought in in advance to construct the structure, which may make it unusable in situations where the ground is unstable, such as during a disaster. In particular, with gantry-type 3D printers, the build size is limited to the range of motion of the actuator, making it difficult to build in narrow spaces where the actuator cannot enter. In the case of the technology described in Patent Document 2, pipes and pumps are required to supply the layering material to the blowing nozzle, so there were limitations to miniaturizing the entire system. Furthermore, in the technology described in Patent Document 3, which involves placing materials transported by a drone onto a structure and stacking them, since the building materials extruded by a nozzle are simply stacked, it is difficult to create a clean surface for the structure, and there is a risk that the structure will not have sufficient rigidity.

[0007] Therefore, conventional concrete 3D printers, which construct large-scale structures in arbitrary spaces, have faced challenges in enabling the creation of stable and rigid structures while maintaining a compact device and rapid fabrication.

[0008] Therefore, the present invention aims to provide a structural construction system that can construct a stable and rigid structure in a short time while being smaller than the conventional technology, and a structural construction method using this structural construction system.

[0009] To solve the above problems, the present invention employs the following means.

[0010] (1) A structural construction system according to one aspect of the present invention comprises an aircraft that transports unhardened building material blocks to a construction site, and a wireless structure forming device that moves along the construction site and spreads the unhardened building material blocks to construct a structure at the construction site.

[0011] (2) In the structure construction system described in (1) above, the flying object may be a drone.

[0012] (3) In the structure construction system described in (1) or (2) above, the wireless structure forming apparatus may have a mixing and leveling section that includes a screw for mixing and leveling the unhardened building material mass.

[0013] (4) In the structure construction system described in any one of (1) to (3) above, the wireless structure forming device may be provided with a hardening accelerator holding unit for holding a hardening accelerator, and the unhardened building material mass and the hardening accelerator may be mixed in the mixing and spreading unit.

[0014] (5) In the structure construction system described in any one of (1) to (4) above, the wireless structure forming device is equipped with wheels that clamp the left and right side walls of the structure, and the angle of the wheels may be tilted at an offset angle with respect to the direction of travel of the wireless structure forming device.

[0015] (6) A method for constructing a structure according to one aspect of the present invention is a method for constructing a structure using the structure construction system described in any one of (1) to (5) above, which may include a building material transport step of transporting the unhardened building material mass to the construction site using the flying body, and a spreading step of spreading the transported unhardened building material mass at the construction site using the wireless structure forming device.

[0016] (7) The method for constructing a structure as described in (6) above may further include: a formwork member transport step of transporting formwork members to the construction site using the flying vehicle; a formwork member installation step of laying the formwork members on at least one surface of the construction site using the wireless structure forming device; and a formwork member removal step of removing the formwork members after constructing the structure by repeating the building material transport step and the laying step.

[0017] (8) In the method for constructing a structure described in (6) or (7) above, in the leveling step, the wireless structure forming device may be used to form uneven surfaces on the construction site.

[0018] (9) In the method for constructing a structure described in any one of (6) to (8) above, the method may further include a scaffolding installation step which is performed before the building material transport step and in which scaffolding members are installed on the construction site, and the unhardened building material lumps may be transported to the top of the scaffolding members and spread out.

[0019] (10) In the method of constructing a structure described in (9) above, the upper surface of the scaffolding member may have a slope that is concave downward from both ends in the width direction toward the center.

[0020] According to the embodiments described in (1) to (10) above, it is possible to provide a structural construction system that can construct a stable structure in a short time while being smaller than the conventional technology, and a structural construction method using this structural construction system.

[0021] This is an external view showing a schematic of the structure construction system according to the first embodiment. This is an external perspective view of the stacked robot according to the first embodiment. This is a front view of the screw according to the first embodiment. This is an external perspective view of the stacked robot according to the second embodiment. This is a schematic diagram showing the scaffolding installation process of the structure construction method according to the fourth embodiment. This is a schematic diagram showing the scaffolding installation process of the structure construction method according to a modified example of the fourth embodiment. This is a cross-sectional view of the scaffolding member. This is a cross-sectional view showing another configuration of the scaffolding member.

[0022] Preferred embodiments of the present invention will be described in detail below with reference to the drawings, but the present invention is not limited to the drawings. In the following description and drawings, the same or corresponding elements will be denoted by the same reference numerals, and redundant descriptions may be omitted. In the following description, the direction along the direction of travel of the stacked robot 3 may be referred to as the front-rear direction, the direction along the vertical direction may be referred to as the up-down direction, and the direction perpendicular to the front-rear direction and the up-down direction may be referred to as the left-right direction.

[0023] (First Embodiment) (Structure Construction System) Figure 1 is an external view showing a schematic of the structure construction system 1 according to the first embodiment. The structure construction system 1 of this embodiment comprises one or more drones 2 (the flying object of the claim) and a stacking robot 3 (the wireless structure forming device of the claim). The stacking robot 3 is a concrete 3D printer (3DCP) auxiliary device that constructs a large structure ST such as a house by three-dimensional molding on an installation surface Gr such as the ground. The structure construction system 1 is a system for constructing a structure ST in space using the drones 2 and the stacking robot 3. In this embodiment shown in Figure 1, the case in which a cylindrical structure ST is constructed is described as an example, but the shape of the structure ST is not limited to the shape of the embodiment.

[0024] As shown in Figure 1, the drone 2 transports unhardened mortar lumps 11 (unhardened building material lumps according to the claim), which are building materials for the structure ST, to the upper part of a predetermined construction area 15. The mortar lumps 11 are, for example, mortar that has been divided into predetermined amounts before hardening. The mortar may be, for example, prepared by mixing cement, coarse aggregate, water, etc., and the W / C ratio may be arbitrarily adjusted in the range of 0.15 to 0.7. The mortar may also be used in combination with admixtures such as water-reducing agents and thickening agents. The mixing ratio and materials of the mortar are not limited to the above configuration. The drone 2 intermittently arranges the mortar lumps 11 thus formed along, for example, the upper part of the construction area 15. The transport position of the mortar lumps 11 is not limited to the upper part, but should be the optimal location depending on the construction area 15 of the structure ST. In this embodiment, the construction area 15 refers to the uppermost part (formed layer) of the already formed cylindrical structure ST. In other words, in this embodiment, the constructed portion 15 is arc-shaped.

[0025] Figure 2 is an external perspective view of the stacking robot 3 according to the first embodiment. As shown in Figures 1 and 2, the stacking robot 3 moves along the construction area 15 where the mortar blocks 11 are placed by the drone 2, and constructs a structure ST on the construction area 15 using the unhardened mortar blocks 11. The stacking robot 3 of this embodiment is configured to autonomously travel over the upper part of the construction area 15. As shown in Figure 2, the stacking robot 3 of this embodiment comprises a main body 20, a drive unit 21, a mixing and spreading unit 22, and a hardening accelerator holding unit 23.

[0026] The main body 20 is mounted on top of the construction section 15 and contains a power supply and control unit (not shown) for operating the drive unit 21 and the mixing and leveling section 22, which will be described in more detail later. The drive unit 21 is connected to the main body 20 and moves the main body 20 along the construction section 15. In this embodiment, the drive unit 21 has wheels 25 that rotate around an axle extending downward from the main body 20. The drive unit 21 has a total of six wheels 25 that contact the left wall 16 and the right wall 17 of the construction section 15, respectively. As each wheel 25 rotates, the stacking robot 3 travels along the top of the construction section 15. In addition, the surface of each wheel 25 has grooves, protrusions, and other uneven shapes that correspond to the uneven parts 45 formed on each side wall. The uneven shapes of the wheels 25 and the uneven parts 45 formed on the side walls engage with each other, restricting the vertical movement of the stacking robot 3.

[0027] The mixing and spreading unit 22 has a screw 8 (see also Figure 3) located on the front side in the direction of travel of the stacking robot 3. The mixing and spreading unit 22 uses the screw 8 to mix and spread the unhardened mortar lumps 11 placed in front of the stacking robot 3. The rotation speed of the screw 8 is controlled independently of the travel speed of the stacking robot 3. In the mixing and spreading unit 22, the screw 8 may perform both mixing and spreading, or the screw 8 may perform spreading while mixing a mixture of a hardening accelerator and the like supplied from the hardening accelerator holding unit 23 (described later) which has been mixed in a separate mixing device.

[0028] Figure 3 is a front view of a screw 8 according to the first embodiment. As shown in Figure 3, the screw 8 has a cylindrical shaft member 28 that rotates at a predetermined rotational speed around an axis along the left-right direction, and a helical fin 29 provided on the outer circumference of the shaft member 28. The fin 29 is provided over the entire axial direction of the shaft member 28 and is formed in a symmetrical shape with the helical inclination direction differing on the right and left sides from the axial center of the shaft member 28. The screw 8 has parameters such as the total length W1 along the axial direction, the length W2 from one end to the center in the axial direction, the outer diameter D of the fin 29, the diameter d of the shaft member 28, the pitch p of the fin 29, and the height h of the fin 29 from the outer circumference of the shaft member 28. In this embodiment, for example, W1 = 50 mm and W2 = 25 mm. W1 and W2 can be changed as appropriate depending on the construction part 15, etc. The values ​​of other parameters will be described later.

[0029] As shown in Figure 2, the hardening accelerator holder 23 is provided in the main body 20 and holds the hardening accelerator inside. The hardening accelerator is used, for example, by mixing it with the mortar mass 11 to accelerate the hardening of the mortar or to increase the strength of the mortar. The hardening accelerator holder 23 supplies the hardening accelerator to the mixing and spreading unit 22 at a predetermined timing. In the mixing and spreading unit 22, the unhardened mortar mass 11 and the hardening accelerator are mixed. The hardening accelerator may be mixed throughout the mortar mass 11, or it may be mixed only in a part of the mortar mass 11. For example, when the mortar mass 11 is spread and a structure ST is formed, the hardening accelerator may be supplied only to the ends of the mortar corresponding to the left and right side walls of the structure ST. In this case, the left and right side walls of the structure ST are firmly formed by the mortar mixed with the effect accelerator, so the structure ST does not deform under the weight of the layering robot 3, and the scaffolding of the layering robot 3 is stabilized when creating the upper layer, thereby enabling stable layering.

[0030] With the above configuration, the stacking robot 3 mixes the unhardened mortar lumps 11 transported by the drone 2 with a hardening accelerator in the mixing and leveling section 22, and then spreads the mortar lumps 11 with the screw 8. As a result, a structure (structure ST) is formed in the construction area 15 that is continuous in the front-to-back direction, spreads out in the left-to-right direction, and has a height along the vertical direction that is set to a desired height. Furthermore, since the unhardened mortar lumps 11, which are the building material, are transported by the drone 2, the stacking robot 3 is formed without having pipes, pumps, or the like for supplying building material to the stacking robot 3. In other words, the stacking robot 3 of this embodiment has a wireless configuration that does not have pipes or the like for connecting to external devices.

[0031] Table 1 shows the experimental results of a qualitative evaluation of how the state of the fabricated object changes depending on the various parameters of the screw 8 shown in Figure 3 above. In the experiment, a total of eight experimental data sets (A-1 to B-4) were obtained by changing the type of mortar and four parameters of the screw 8: the outer diameter D of the fin 29, the diameter d of the shaft member 28, the pitch p of the fin 29, and the height h of the fin 29.

[0032]

[0033] Data numbers A-1 to A-4 in Table 1 show experimental results using mortar A, a commonly used mortar made by mixing cement, coarse aggregate, and water. Data numbers B-1 to B-4 in Table 1 show experimental results using mortar B, which has a different composition from mortar A and has a proven track record in the field of concrete 3D printing. Mortar B may be a mortar that is composed to flow more easily than mortar A, for example. Data numbers A-1 and B-1 show results using screw 8 with D=80mm, d=70mm, p=10mm, h=5mm. Data numbers A-2 and B-2 show results using screw 8 with D=22mm, d=12mm, p=10mm, h=5mm. Data numbers A-3 and B-3 show results using screw 8 with D=60mm, d=40mm, p=25mm, h=10mm. Data numbers A-4 and B-4 show the results using screw 8 with D=60 mm, d=40 mm, p=8.5 mm, and h=10 mm.

[0034] In the experiment, the distance s from the ground to the outer diameter of the screw 8 was kept constant at 5 mm (see also Figure 3), and two mortar blocks 11 were placed in succession facing the screw 8. Then, the screw 8, which was rotating at a constant speed (20.5 rpm in this experiment) by a servo motor, was scanned linearly to create three layers in the vertical direction. After all layers were completed, the width dimension along the left-right direction and the height dimension along the vertical direction of the formed object were measured at three appropriate locations on the mortar (i.e., structure ST) after layering. Note that the target shape of the mortar after layering differs depending on the height h of the fins 29 of the screw 8. For data numbers A-1, A-2, B-1, and B-2, the target shape was set to a height of 30 mm along the vertical direction and a width of 50 mm along the left-right direction. For data numbers A-3, A-4, B-3, and B-4, the target shape was set to a height of 35 mm along the vertical direction and a width of 50 mm along the left-right direction. Under the above conditions, lamination experiments were conducted for each of the data numbers A-1 to B-4, and the degree of adhesion of the mortar to the screw 8 after lamination, the degree of adhesion between the upper and lower layers, the degree of fusion between the two mortar lumps 11 in each layer, the degree of pressure feeding in the width direction (left and right direction) of the screw 8, the forward thrust force generated by the rotation of the screw 8 when stretching the mortar, the vertical reaction force acting on the screw 8 as measured by a force gauge, the current value of the servo motor, and various dimensions of the molded object were evaluated. Note that the measurement direction of the reaction force differs between mortar A and mortar B.

[0035] Table 1 shows that both mortars A and B have many circles (good) in the evaluation items, and that a small reaction force and a small current value are desirable conditions. First, considering the screw diameters D and d, for example, comparing data numbers B-1 and B-2, it can be seen that the reaction force increases as the outer diameters D and d of the screw 8 increase, so it is important that the screw diameters D and d do not become too large. On the other hand, Table 1 shows that if the screw diameters D and d are too small, interlayer adhesion does not progress, so an outer diameter of D and d that is too small is also problematic. Furthermore, it was found that if the spacing p of the fins 29 is too wide, depending on the type of mortar, the fusion of the mortar in each layer may not be good, as shown in B-3 for example. For this reason, it was found that the screw 8 with the parameters of data numbers A-4 and B-4 is suitable as a spreading mechanism because it has no interlayer adhesion, a moderate reaction force, and good mortar fusion in each layer regardless of the type of mortar. Furthermore, comparing data numbers B-1 and B-2, for example, it was found that the reaction force increases as the outer diameter of the screw 8 increases. Regarding the type of mortar, since the thrust force is low and the servo motor current value is small, mortar B is considered more suitable. Mortar B also has the characteristics of hardening in a shorter time and having higher strength than mortar A, so when constructing structures by lamination, mortar B is considered more suitable.

[0036] Furthermore, measurements of the dimensions of the fabricated objects after lamination for data numbers B-3 and B-4 confirmed that both achieved the target shape. However, in the fabricated object for data number B-3, multiple voids were found in the cross-section compared to the fabricated object for data number B-4. In contrast, the fabricated object for data number B-4 showed fewer voids and was found to be densely packed with mortar. In other words, the fabricated object for data number B-4 showed a better degree of fusion between the mortar lumps 11 than the fabricated object for data number B-3. This is thought to be because a smaller pitch p of the screw 8 increased the number of times the fins 29 of the screw 8 came into contact with the mortar during a single lamination, resulting in more agitation of the mortar. Additionally, a smaller pitch p allows for more effective leveling by the compaction of the screw 8, leading to a higher degree of fusion of the mortar between upper and lower layers, and consequently, fewer voids between the upper and lower layers.

[0037] Based on the above, among the eight data points used in this experiment, the screw shape of data point B-4, which uses mortar B, has a small pitch p, and a relatively large fin height h, is the optimal one.

[0038] Table 2 shows the results of an experiment conducted separately from the one described above. This experiment evaluated whether it was possible to fabricate a structure ST with curvature using the structure construction system 1 described above. In this experiment, the radius of curvature R of the fabricated structure was varied to 300 mm and 200 mm, and two sets of experimental data (C-1 and C-2) were obtained.

[0039]

[0040] In this experiment, a circular arc-shaped object with a radius of curvature R is fabricated using the screw 8 and mortar B of data number B-4, which yielded optimal results in the aforementioned experiment. First, the screw 8 is attached to an arm set so that the distance from the center of the arc of the fabricated object to the center of the screw 8 in the axial direction is a predetermined radius of curvature R, allowing the screw 8 to rotate around the center of the arc. Three mortar blocks 11 are then placed in front of the screw 8 along the trajectory of the arc. The screw 8, which is rotating at a constant speed (20.5 rpm in this experiment) by a servo motor, is scanned along the curved surface of the arc, and three layers are laid in the vertical direction. Note that in data number C-2, two layers were laid in the vertical direction. After all the layers are completed, the width dimension along the left-right direction and the height dimension along the vertical direction of the fabricated object are measured at three appropriate locations on the mortar (i.e., structure ST) after layering. Note that the target shape of the mortar after layering differs depending on the radius of curvature R. Therefore, for data number C-1, the target shape was set to have a width of 50 mm along the left-right direction and a height of 35 mm along the up-down direction. For data number C-2, the target shape was set to have a width of 50 mm along the left-right direction and a height of 25 mm along the up-down direction. Under these conditions, layering experiments were conducted for both data numbers C-1 and C-2, and the shape and various dimensions of the fabricated objects after layering were evaluated.

[0041] Regarding the shape of the molded object, experimental results confirmed that it is possible to create objects with the specified radius of curvature for both R=300 mm and R=200 mm. For the evaluation of the molded object's shape, arcs corresponding to each radius of curvature were drawn in advance on the plane where the mortar would be molded. After molding, the feasibility of the molding was determined visually using these drawn lines as a reference.

[0042] Data number C-1 in Table 2 shows the measurement results of various dimensional values when the radius of curvature R = 300 mm. Data number C-2 in Table 1 shows the measurement results of various dimensional values when the radius of curvature R = 200 mm. Regarding various dimensional values of the shaped object after lamination, experiments were repeated three times, and each value and its average value were calculated for evaluation. As shown in Table 2, particularly, the average value of the height dimension of data number C-1 with a radius of curvature R = 300 mm is 41.50 mm, showing a deviation of 11.5 mm from the target value of 35 mm. The other measurement results were generally as expected. The larger deviation of the height dimension of data number C-1 from the target value compared to that of data number C-2 is considered to be due to the influence of the viscosity of the mortar. That is, it is considered that the viscosity of the mortar during the experiment of data number C-1 was higher than that during the experiment of data number C-2, which had an impact. When the viscosity of the mortar is high, the reaction force acting on the screw 8 when laminating the mortar becomes large, and as a result, the height dimension of the shaped object tends to become large.

[0043] From the above, according to this experiment, it was obtained that the structured object ST with a curvature can be shaped by the above-described structure construction system 1. Also, it was obtained that the viscosity of the mortar may affect the lamination result.

[0044] (Structure construction method) Next, a structure construction method using the above-described structure construction system 1 will be described. The structure construction method includes a building material conveying step and a leveling step. In the building material conveying step, the drone 2 conveys the uncured mortar block 11 to the construction site 15 of the structured object ST. In the leveling step, the conveyed uncured mortar block 11 is leveled at the construction site 15 using the laminating robot 3. Also, in the leveling step, the laminating robot 3 is used to form the concave and convex portions 45 on the side walls 16, 17 of the construction site 15. By going through these steps, the structured object ST can be constructed in an arbitrary space using the structure construction system 1.

[0045] The structure construction system 1 of this embodiment includes a drone 2 (the flying object according to the claim) for transporting unhardened mortar lumps 11 (the building material lumps according to the claim) and a stacking robot 3 (the wireless structure forming device according to the claim). The stacking robot 3 constructs the structure ST on the construction site 15 using the unhardened mortar lumps 11. Since the mortar lumps 11 are transported to the stacking robot 3 by the drone 2, pipes, pumps, etc. for supplying materials to the stacking robot 3 are unnecessary, and the stacking robot 3 can be configured wirelessly. In addition, since the stacking robot 3 moves along the construction site 15, there is no need to place external devices, etc. around the structure ST. As a result, the structure ST can be constructed regardless of the size of the scaffolding. Furthermore, since the mortar lumps 11 are transported by the drone 2, the manufacturing of building materials (e.g., mixing of mortar materials) can be carried out at a location away from the structure ST (e.g., near a water source). As a result, mortar can be supplied stably even if there is no space to manufacture mortar near the structure ST. Therefore, compared to conventional technology, the entire system can be made smaller and used in various environments such as disaster sites. Since the stacking robot 3 and drone 2 can operate automatically for 24 hours, the structure ST can be constructed in a short time. In addition, since the unhardened mortar lumps 11 transported by the drone 2 are stacked using the stacking robot 3, the building materials can be stacked with high strength. Therefore, compared to conventional technology, for example, in which material is squeezed and supplied directly from the drone 2 to the construction site 15, the strength of the structure ST can be increased. Thus, a structure construction system 1 can be provided that is smaller than conventional technology and can construct a stable structure ST in a short time.

[0046] Since drone 2 is used as the flying object, the placement location and timing of the mortar blocks 11 can be controlled with high precision. Therefore, a highly accurate and stable structure ST can be constructed. In addition, since multiple drones 2 can be used to supply the mortar blocks 11, the structure ST can be constructed in a shorter time.

[0047] The stacked robot 3 has a mixing and leveling unit 22 that includes a screw 8 for mixing the uncured mortar blocks 11. Thereby, while mixing the mortar blocks 11, the mortar can be stretched in the traveling direction of the stacked robot 3. Also, while spreading the mixed mortar in the left-right direction by the screw 8, a shaped object can be formed. Furthermore, the adhesion force between the mortars can be strengthened by the rolling pressure during the rotation of the screw 8. Thus, a shaped layer of a desired size can be formed, and a high-strength and stable structure ST can be constructed.

[0048] The stacked robot 3 includes a curing accelerator holding unit 23 that holds a curing accelerator, and mixes the uncured mortar blocks 11 and the curing accelerator in the mixing and leveling unit 22. By mixing the curing accelerator, the mortar can be cured in a shorter time, so the shaping time can be shortened. Furthermore, by mixing the curing accelerator into the mortar, the strength of the cured mortar is improved. Thereby, the strength of the construction site 15 (that is, the already shaped structure ST) which is the scaffold for the self-propelled stacked robot 3 is increased, so that even when the stacked robot 3 shapes while pumping the mortar, the shaping can be performed without succumbing to the reaction force during pumping. Thus, the strength of the structure ST can be increased and stable shaping can be performed.

[0049] Also, according to the structure construction method of the present embodiment, the structure construction method includes a building material transportation step and a leveling step. In the building material transportation step, the drone 2 transports the uncured mortar blocks 11 to the construction site 15. In the leveling step, the transported uncured mortar blocks 11 are leveled at the construction site 15 using the stacked robot 3. Thus, with the compact structure construction system 1 compared to the prior art, a stable structure ST can be constructed in a short time and uniformly. Therefore, a structure construction method using the above-described structure construction system 1 that can construct a stable structure ST in a short time while being miniaturized compared to the prior art can be provided.

[0050] In the spreading process, the stacking robot 3 is used to form uneven surfaces 45 on the construction area 15. For example, by forming uneven surfaces (not shown) on the upper surface of the structure ST, the mortar layers stacked vertically can be firmly bonded together. Also, for example, if uneven surfaces 45 are formed on the left and right side walls 16, 17 of the structure ST (see Figure 2), the wheels 25 of the stacking robot 3 can grip these uneven surfaces 45. This allows the mortar to be pumped and shaped simultaneously. Therefore, the stacking strength between the mortar layers is increased, and a stable structure ST can be constructed.

[0051] (Second Embodiment) Next, a second embodiment of the present invention will be described. In the description of the second embodiment, components similar to those in the first embodiment described above will be denoted by the same reference numerals and their descriptions will be omitted as appropriate. Note that the specific configuration is not limited to these embodiments and can be modified as appropriate without departing from the spirit of the present invention. Figure 4 is an external perspective view of the stacking robot 203 according to the second embodiment. The second embodiment differs from the first embodiment described above in that the mortar blocks 11 transported by the drone 2 are directly supplied to the stacking robot 203.

[0052] As shown in Figure 4, in the second embodiment, the stacking robot 203 has a mortar receiving section 230 in addition to the configuration of the stacking robot 3 in the first embodiment. The mortar receiving section 230 is provided, for example, on the main body 20 of the stacking robot 203 and has an upward opening to allow it to receive mortar lumps 11. The mortar receiving section 230 supplies the mortar lumps 11 transported by the drone 2 to the mixing and leveling section 22 of the stacking robot 203. Therefore, the mixing and leveling section 22 levels the mortar supplied from the mortar receiving section 230 while stirring it with the screw 8.

[0053] The structural construction system 201 of the second embodiment can achieve the same effects as the first embodiment described above. Therefore, the versatility of the stacked robot in the structural construction system 201 can be improved.

[0054] (Third Embodiment) Next, a method for constructing a structure according to the third embodiment of the present invention will be described. The third embodiment differs from the first embodiment described above in that the structure is formed using formwork members (not shown) in conjunction with the mortar mass 11.

[0055] The structure construction method of the third embodiment comprises a formwork member transport step, a formwork member installation step, the building material transport step and leveling step described above, and a formwork member removal step. In the formwork member transport step, the formwork members are transported to the construction site 15 by a drone 2. The formwork members are pre-formed block materials or wooden frames, etc. The formwork members are formed from, for example, resin material or wood. In the formwork member installation step, the transported formwork members are laid on at least one surface of the construction site 15 using a stacking robot 3. The building material transport step and leveling step are the same as the building material transport step and leveling step in the first embodiment described above, so a detailed explanation is omitted. In this embodiment, a structure ST is formed by spreading and leveling mortar by the stacking robot 3 at a position adjacent to the formwork members installed in the formwork member installation step. After constructing the structure ST by repeating the building material transport step and the leveling step, the formwork member removal step is performed. In the formwork member removal process, the formwork members are removed using at least one of the drone 2 and the stacking robot 3, but they may also be removed by humans after completion.

[0056] According to the structure construction method of the third embodiment, the structure construction method further comprises a formwork member transport step, a formwork member installation step, and a formwork member removal step. Since the structure ST is constructed by repeatedly laying formwork members and shaping using unhardened mortar lumps 11, the formwork members provide a stronger footing for the stacking robot 3, and stable shaping can be performed without deformation of the structure ST due to the weight of the stacking robot 3 or the stacking mortar. Furthermore, since the formwork members can be removed using a drone 2 or the stacking robot 3 after the structure ST is constructed, the size of the structure construction system 1 can be kept down even when formwork members are used. Thus, it is possible to achieve both miniaturization of the overall system configuration and stable shaping.

[0057] (Fourth Embodiment) Next, a structure construction method according to the fourth embodiment of the present invention will be described. Figure 5 is a schematic diagram showing the scaffolding installation process of the structure construction method according to the fourth embodiment. Figure 6 is a schematic diagram showing the scaffolding installation process of a structure construction method according to a modified example of the fourth embodiment. Figure 7 is a cross-sectional view of the scaffolding member 450. Figure 8 is a cross-sectional view showing another configuration of the scaffolding member 450. The structure construction method of the fourth embodiment differs from the first embodiment described above in that, in addition to the building material transport process and the spreading process of the first embodiment described above, it further includes a scaffolding installation process. In the following description, when scaffolding member 450A and scaffolding member 450B are not distinguished from each other, they may be collectively referred to as scaffolding member 450.

[0058] The fourth embodiment of the structure construction method comprises a scaffolding installation step, a building material transport step, and a leveling step. As shown in Figure 5, in the scaffolding installation step, scaffolding members 450A are installed on the installation surface Gr (ground). The scaffolding members 450A are formed, for example, in the shape of a rectangular frame in plan view. The scaffolding members 450A are, for example, manufactured in advance at another location and then transported to the location (installation surface Gr) where the structure ST will be constructed. The lower surface of the scaffolding members 450A is formed to match the shape of the unevenness of the installation surface Gr. The material of the scaffolding members 450A may be, for example, reinforced concrete, resin, mortar, wood, metal, etc. The scaffolding members 450A may be transported in a state divided into multiple parts. It is preferable that the scaffolding members 450A are fixed to the ground surface Gr.

[0059] Once the scaffolding members 450A are installed, the scaffolding installation process is complete. In the building material transport process, unhardened mortar lumps 11 (see Figure 1) are transported to the top of the installed scaffolding members 450A. Then, in the spreading process, the transported unhardened mortar lumps 11 are spread and leveled using the stacking robot 3 (see Figure 1), thereby constructing the structure ST above the scaffolding members 450A.

[0060] Figure 6 shows another example (modified version) of the scaffolding member 450. As shown in Figure 6, the scaffolding member 450B may be installed in the air away from the installation surface Gr (ground) by being attached to a support member 19 that extends vertically upward from the ground Gr. In the example shown in Figure 6, a tree growing on the ground is used as the support member 19. In the scaffolding installation process, the scaffolding member 450B, which is rectangular in shape in plan view, is attached to this tree 19. In addition to the frame body 451 on which the structure ST is constructed in a later process, the scaffolding member 450B may include a connecting part 452 for fixing the frame body 451 to the support member 19.

[0061] As shown in Figure 7, the upper surface 455 of the scaffolding member 450 (the frame body 451), that is, the surface on which mortar is spread during the spreading process, may have an inclined surface that is concave downwards from both ends in the width direction toward the center. In this embodiment, the angle of inclination θ is set to 15° or less. The angle of inclination θ may be changed depending on the physical properties of the mortar mass 11 to be transported in a later process, the size of the structure ST, etc. As shown in Figure 8, the upper surface 455 of the scaffolding member 450 may have a curved surface that is concave downwards from both ends in the width direction toward the center.

[0062] According to the fourth embodiment of the structure construction method, the structure construction method includes a scaffolding installation step of installing scaffolding members 450 (450A and 450B). By having a step of installing the scaffolding members 450 before the building material transport step and the leveling step, the mortar can be leveled while the scaffolding is stabilized, using the scaffolding members 450 as a base. Therefore, even if, for example, the installation surface Gr is not flat, or if it is desired to construct a structure ST in the air away from the ground, stable leveling can be performed, thereby increasing the versatility of the structure construction method of this embodiment.

[0063] The upper surface 455 of the scaffolding member 450 is formed to be concave downwards from both ends in the width direction towards the center. This allows the mortar lumps 11 to be stably placed on top of the scaffolding member 450 in the subsequent building material transport process. Furthermore, since the mortar lumps 11 are less likely to spill out on both sides of the scaffolding member 450 in the width direction, the leveling work can be easily performed, and the stable leveling work allows for the construction of the structure ST with high precision.

[0064] In the fourth embodiment described above, the scaffolding member 450 does not need to be fixed to the ground surface Gr. That is, in the scaffolding installation process, the scaffolding member 450 may simply be placed on the ground surface Gr. The upper surface 455 of the scaffolding member 450 may be subjected to processing or surface treatment to make the surface rougher. This improves the degree of adhesion between the scaffolding member 450 and the mortar, allowing the structure ST to be constructed more stably. The support member 19 is not limited to wood.

[0065] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the first embodiment described above, the stacking robot 3 is held and moved by gripping the left and right side walls 16 and 17 of the already formed structure ST with wheels 25, but the method of moving the stacking robot 3 along the construction area 15 is not limited to this. As an example, a drone (not shown) for suspending the stacking robot may be further provided, and the stacking robot 3 may be held by lifting the main body 20 of the stacking robot 3 with this drone to construct the structure ST. As another example, a support column extending upward from the installation surface Gr and an arm extending horizontally from the support column (neither shown) may be provided, and the stacking robot 3 may be held by attaching the stacking robot 3 to the tip of the arm. As yet another example, the stacking robot 3 may be held by extending the drive unit 21 downward toward the installation surface Gr and providing a wheel that contacts the installation surface Gr at the end of it. In other words, the wheel may be made to travel on the installation surface Gr by a drive unit that can extend and retract in the vertical direction. In these examples, the weight of the stacked robot 3 does not act on the structure ST, so there is no unexpected deformation of the structure ST, and the construction of the structure ST is possible.

[0066] When fabricating a structure ST having curvature, the additive manufacturing robot 3 may be formed to have four or more, more preferably six or more, wheels 25. In this case, curvature may be formed by making the steering angles of the front and rear wheels 25 different from each other. Furthermore, a structure having curvature in the vertical direction may be fabricated. In this case, curvature may be formed by tilting the yaw angle of the wheels 25.

[0067] Furthermore, when the stacking robot 3 is held and moved by gripping the left and right side walls 16 and 17 of the constructed structure ST in the first embodiment with the wheels 25, the stacking robot 3 may gradually fall due to its own weight. Also, when the stacking robot 3 spreads the mortar blocks 11, the stacking robot may lift up due to the reaction force from the mortar blocks 11. In such cases, there is a problem in that the stacking robot 3 cannot stably construct the target structure ST. To solve this problem, the wheels 25 of the stacking robot 3 are tilted upward or downward with respect to the direction of travel. By tilting the wheels 25 upward with respect to the direction of travel, the stacking robot 3 gradually rises, and by tilting them downward, the stacking robot 3 gradually descends. As mentioned above, the force that causes the stacking robot 3 to gradually fall due to its own weight or the reaction force from the mortar blocks 11 causes the stacking robot to lift. It is desirable to operate the stacking robot 3 at a counteracting angle, tilting the wheels 25 relative to the direction of travel, so that the upward or downward force generated by tilting the wheels 25 upward or downward relative to the direction of travel perfectly cancels out, resulting in the target height and shape of the layer to be stacked on the structure ST. The counteracting angle can be determined based on data such as the properties of the mortar, the weight of the stacking robot 3, the peripheral speed of the wheels 25, the rotational speed of the wheels 25, and the coefficient of friction between the wheels 25 and the structure ST. In this way, stable leveling can be achieved by maintaining the stacking robot 3 at the target height on the constructed structure ST and creating a new layer.

[0068] The hardening accelerator holder 23 may be omitted depending on the material of the unhardened building material mass. Alternatively, instead of providing the hardening accelerator holder 23 on the stacking robot 3, the hardening accelerator may be pre-mixed into the mortar mass 11 transported by the drone 2. The hardening accelerator may be mixed into only a portion of the mortar mass 11 transported by the drone 2. In this case, the drone 2 may be controlled so that the portion mixed with the hardening accelerator is placed on both the left and right sides with respect to the direction of travel of the stacking robot 3.

[0069] In addition to the mortar mass 11, reinforcing members may be provided separately. The reinforcing members may be made of, for example, resin, metal, wood, etc., and may be provided to connect multiple layers. The reinforcing members may be transported by a drone 2.

[0070] Furthermore, without departing from the spirit of the present invention, the components in the embodiments described above may be replaced with well-known components, and the embodiments described above may be combined as appropriate.

[0071] 1: Structural construction system 2: Drone (flying vehicle) 3: Lamination robot (wireless structural forming device) 8: Screw 11: Mortar block (unhardened building material block) 15: Construction area 22: Mixing and leveling area 23: Hardening accelerator holding area 45: Uneven area ST: Structure

Claims

1. A structure construction system comprising: an aircraft that transports unhardened building material blocks to a construction site; and a wireless structure forming device that moves along the construction site and spreads the unhardened building material blocks to construct a structure at the construction site.

2. The structure construction system according to claim 1, characterized in that the flying object is a drone.

3. The structure construction system according to claim 1, characterized in that the wireless structure forming apparatus has a mixing and leveling section that includes a screw for mixing and leveling at least one of the uncured building material masses.

4. The structure construction system according to claim 3, wherein the wireless structure forming apparatus comprises a hardening accelerator holding section for holding a hardening accelerator, and the unhardened building material mass and the hardening accelerator are mixed in the mixing and spreading section.

5. The structure construction system according to claim 1, wherein the wireless structure forming apparatus is equipped with wheels that clamp the left and right side walls of the structure, and the angle of the wheels is tilted at an offset angle with respect to the direction of travel of the wireless structure forming apparatus.

6. A method for constructing a structure using the structure construction system described in any one of claims 1 to 5, comprising: a building material transport step of transporting the unhardened building material mass to the construction site using the flying body; and a spreading step of spreading the transported unhardened building material mass at the construction site using the wireless structure forming device.

7. A method for constructing a structure according to claim 6, further comprising: a formwork member transport step of transporting formwork members to the construction site using the aircraft; a formwork member installation step of laying the formwork members on at least one surface of the construction site using the wireless structure forming device; and a formwork member removal step of removing the formwork members after constructing the structure by repeating the building material transport step and the laying step.

8. The method for constructing a structure according to claim 6, wherein in the leveling step, an uneven surface is formed on the construction site using the wireless structure forming apparatus.

9. A method for constructing a structure according to claim 6, further comprising a scaffolding installation step, which is performed prior to the building material transport step, wherein scaffolding members are installed on the construction site, and the unhardened building material lumps are transported to the top of the scaffolding members and spread out.

10. The method for constructing a structure according to claim 9, wherein the upper surface of the scaffolding member has a slope that is concave downward from both ends in the width direction toward the center.

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