Structural formation system and structural formation method

Abstract

To provide a structure formation system and a structure formation method for suppressing failures upon changing a discharge amount of a molding material.SOLUTION: A 3D printer 20 forms a frame member laminated by piling up layers formed by mortar discharged from a nozzle 23 while moving the nozzle 23. The 3D printer 20 comprises: a control part 31 controlling the lamination; a pump 21 pressure-sending the mortar to the nozzle 23; and a valve 24 provided at a space between the nozzle 23 and a feed part 22 connected to the pump 21. The valve 24 is a pinch valve closed by clogging a flow passage by an internal flexible tube.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a structure forming system and a structure forming method for forming a structure by laminating a molding material discharged from a moving nozzle.

Background Art

[0002] When forming a three-dimensional structure such as a building, a three-dimensional (3D) printer may be used. In this 3D printer, a layer is formed by moving a nozzle while discharging a material from the nozzle, and a structure having a three-dimensional shape is formed by gradually stacking the formed layers (see, for example, Patent Document 1). In the structure described in Patent Document 1, the outer frame and the inner frame of the structure are laminated by moving the nozzle while discharging a first mortar of a first composition from the nozzle. Then, an internal structure is formed by injecting a second mortar of a second composition different from the first composition into the space surrounded by the outer frame and the inner frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In 3D printing, mortar is pumped to the nozzle under pressure, and then the pressure of the mortar is used to extrude it from the nozzle. This mortar is then layered to form a structure. Therefore, when stopping the mortar flow at the end of a structure, simply stopping the pump is insufficient because the mortar pressure remains, causing it to continue extruding beyond the intended stopping point. This sometimes resulted in excessive mortar being extruded at the end of the structure. Furthermore, when forming the end of the first layer (bottom layer) of a structure, simply starting the pump sometimes resulted in insufficient mortar being extruded from the nozzle. [Means for solving the problem]

[0005] The structure forming system that solves the above problem moves the nozzle while 、 The nozzle From the downward-facing outlet Discharged Cement-based materials A system for forming a stacked structure by stacking layers formed by the same, comprising a control unit for controlling the stacking, and the Cement-based materials The system comprises a pump that pressurizes the fluid to the nozzle, and a valve provided between the nozzle and the connection part that connects to the pump, wherein the valve is a pinch valve that closes by blocking the flow path with a flexible tube. Furthermore, the control unit moves the nozzle and, at the time of arrival at the endpoint where the nozzle reaches the design endpoint of the structure, which is determined from the shape of the structure, the speed of movement of the nozzle, and the timing of operation, the valve is completely closed, from the time of arrival at the endpoint until the time required for the valve to begin closing and the tube to completely close by blocking the flow path, before At the valve closing start time, when compressed air is to be supplied to the outer circumference of the tube, the valve is closed. From the valve closing start time, the pump is stopped at the pump stop time, which is before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump. From the end point arrival time, the nozzle is moved along the portion of the structure continuous with the end point until the movement end time, when the amount of cement-based material remaining from the tube to the nozzle outlet, which was calculated in advance by experiment or calculation, is finished to be discharged. At the movement end time, the nozzle is moved above the structure, thereby separating the nozzle from the structure. . Furthermore, a structure forming system that solves the above problems is a system that forms a stacked structure by stacking layers formed of cement-based material discharged from a discharge port facing downward of the nozzle while moving the nozzle, comprising a control unit that controls the stacking, a pump that pressurizes the cement-based material to the nozzle, and a valve provided between the nozzle and a connection part connected to the pump, wherein the valve is a pinch valve that closes by blocking the flow path with a flexible tube, and the control unit, while moving the nozzle, determines the arrival time of the nozzle at the design end point of the structure, which is determined from the shape of the structure and the speed and timing of the movement of the nozzle, and the pump At the time the pump is stopped before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump, the pump is stopped, at the time of arrival at the endpoint, the valve is started to close, and from the time of arrival at the endpoint, after the time required for the valve to close completely by blocking the flow path from the start of valve closing has elapsed, until the time of completion of movement, when the amount of cement-based material remaining from the tube to the nozzle outlet, which has been calculated in advance by experiment or calculation, is finished to be discharged, the nozzle is moved along the portion of the structure that is continuous with the endpoint, and at the time of completion of movement, the nozzle is moved above the structure, thereby separating the nozzle from the structure. [Effects of the Invention]

[0006] According to the present invention, problems when changing the amount of material extruded can be suppressed. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the structure in the embodiment. [Figure 2] This is an explanatory diagram illustrating the structure of the structure formation system in the embodiment. [Figure 3] This is an explanatory diagram of the hardware configuration in the embodiment. [Figure 4] This is an explanatory diagram illustrating the configuration of the main parts around the nozzle of the structure forming system in the embodiment. [Figure 5] This is an explanatory diagram illustrating the configuration of a valve in a structural forming system according to an embodiment, where (a) is a schematic cross-sectional view when the valve is open and (b) is a schematic cross-sectional view when the valve is closed. [Figure 6] This is an explanatory diagram illustrating the structure of the creation support server in the embodiment. [Figure 7] This is an explanatory diagram illustrating the end termination control process in the embodiment. [Figure 8] This is a flowchart illustrating the processing procedure for end-of-cycle termination control in the embodiment. [Figure 9] This is an explanatory diagram illustrating the end-start control process in the embodiment. [Figure 10] This is a flowchart illustrating the processing procedure for the end-start control process in the embodiment. [Figure 11] This flowchart illustrates the end termination control process in the modified example. [Modes for carrying out the invention]

[0008] Below, an embodiment illustrating the structure formation system and structure formation method will be described using Figures 1 to 10. As shown in Figure 1, the structure 10 of this embodiment has a substantially rectangular parallelepiped shape overall and has a plurality of cavities E1. This structure 10 comprises an outer frame member 11 that constitutes the outer shape and inner frame members 12 and 13 that form the shape of the cavities E1. When a structure is formed by stacking using a 3D printer, striped stacking marks often remain in the horizontal direction, but in Figure 1, for simplification, the striped stacking marks formed on the frame members (11-13) are omitted.

[0009] The outer frame member 11 and the inner frame members 12 and 13 are structures constructed by layering a first mortar as a molding material using a 3D printer. The first mortar is a cement-based material that has the properties of hardening and can be layered using a 3D printer.

[0010] In the region surrounded by the outer frame member 11 and the inner frame members 12 and 13, an internal structure 15 is formed. This internal structure 15 is composed of a second mortar having a higher strength than the first composition of the first mortar. In the present embodiment, as the second mortar, for example, a cement-based material (fiber reinforced concrete material) mixed with fibers such as Slimcrete (registered trademark) is used. This internal structure 15 is integrated with the frame members (11 to 13) by being hardened after filling the region surrounded by the outer frame member 11 and the inner frame members 12 and 13 with the second mortar.

[0011] (Configuration of 3D printer 20 and creation support server 40) Next, with reference to FIGS. 2 to 6, the 3D printer 20 and the creation support server 40 that form the frame members (11 to 13) of the structure 10 described above will be described.

[0012] (Example of hardware configuration) FIG. 3 is an example of the hardware configuration of an information processing apparatus H10 that functions as a control apparatus 30 of the 3D printer 20 and a creation support server 40 or the like.

[0013] The information processing apparatus H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and it may have other hardware.

[0014] The communication device H11 is an interface that establishes a communication path with other devices and executes data transmission and reception, and is, for example, a network interface or a wireless interface.

[0015] The input device H12 is a device that receives input from a user or the like, and is, for example, a mouse or a keyboard. The display device H13 is a display or a touch panel that displays various information.

[0016] The storage device H14 is a storage unit (for example, the ejection path storage unit 42 described later) that stores data and various programs for executing various functions of the control device 30 and the creation support server 40. Examples of storage devices H14 include ROM, RAM, and hard disks.

[0017] The processor H15 uses programs and data stored in the memory device H14 to control various processes in the control device 30, the creation support server 40, and user terminals (not shown) connected thereto (for example, processes in the control units 31 and 41, which will be described later). An example of the processor H15 is a CPU or MPU. This processor H15 loads programs stored in ROM, etc., into RAM and executes various processes corresponding to various operations. For example, when the application programs of the control device 30 and the creation support server 40 are started, the processor H15 operates the processes that execute the various operations described later.

[0018] The processor H15 is not limited to performing all of its operations through software processing. For example, the processor H15 may include dedicated hardware circuits (e.g., application-specific integrated circuits: ASICs) that perform hardware processing for at least some of the operations it performs. In other words, the processor H15 may be configured as follows:

[0019] (1) One or more processors that operate according to a computer program (software) (2) One or more dedicated hardware circuits that perform at least some of the various processes, (3) Circuits that include combinations of those.

[0020] A processor includes a CPU and memory such as RAM and ROM, where memory stores program code or instructions configured to cause the CPU to perform processing. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer.

[0021] (3D Printer 20 Features) The 3D printer 20 shown in Figure 2 functions as a structure forming system and includes a pump 21, a supply unit 22, a nozzle 23, a valve 24, a robot 27, and a control device 30.

[0022] Pump 21 pressurizes the supplied mortar and pumps it to the nozzle 23 via the supply unit 22 so that the supplied mortar is discharged from the nozzle 23. The supply unit 22 is a connection unit that connects the pump 21 and the nozzle 23, and is composed of a hose or a supply pipe provided at the end of the hose. The supply unit 22 supplies pressurized mortar from the pump 21 to the nozzle 23.

[0023] Figure 4 is an enlarged view of the configuration around the nozzle 23 in the 3D printer 20. The nozzle 23 is composed of a tubular member with a length NL1 and has an open discharge port 23a at its tip. The arm 27a of the robot 27 is attached to the nozzle 23 via a mounting part 28, and the nozzle 23 is supported by the arm 27a. The nozzle 23 moves horizontally and vertically in accordance with the movement of the arm 27a. In this embodiment, the nozzle 23 moves such that the discharge port 23a always faces downward.

[0024] A valve 24 is connected to the upstream side of the nozzle 23. This valve 24 is positioned between the supply unit 22 and the nozzle 23. In this embodiment, a pinch valve is used as the valve 24. As shown in Figure 5(a), the valve 24 has a tube 55 made of a flexible material such as rubber inside a housing 51 equipped with flanges 51a and 51b. Flange 51a is fixed to the end of the supply section 22, and flange 51b is fixed to the end of the nozzle 23.

[0025] As shown in Figure 5(b), in this embodiment, when compressed air is supplied to the outer circumference of the tube 55 of the housing 51 via the air supply pipe 26, the tube 55 expands inward. As a result, the tube 55 blocks the flow path of the valve 24, and the valve 24 closes. Therefore, in this embodiment, the valve 24 requires a predetermined time (valve closing time) from when the valve closing starts and the tube 55 begins to expand until the tube 55 completely blocks the flow path and the valve is completely closed.

[0026] Furthermore, the valve 24 opens the passage by exhausting the compressed air supplied around the tube 55, thereby deflating the tube 55. Even when the valve is open, a predetermined time (valve opening time) is required from the start of opening until the valve is fully open.

[0027] As shown in Figure 4, a compressor 25 is connected to the valve 24 via an air supply pipe 26. This compressor 25 is controlled by the valve control unit 317 of the control unit 31, which will be described later.

[0028] (Configuration of the control device 30) The control device 30 shown in Figure 2 includes a control unit 31 that performs structure formation processing. Therefore, by executing the structure formation program stored in the memory unit, the control unit 31 functions as a stacking management unit 311, a movement control unit 312, a discharge volume control unit 313, a pump control unit 316, a valve control unit 317, and an arm control unit 318.

[0029] The lamination management unit 311 performs processing to manage the path and height of the mortar to be layered in order to form the structure (frame members (11~13)). The lamination management unit 311 counts the number of layers that have been stacked, stores the current number of mortar layers, and stops the movement of the nozzle 23 when the final number of layers for the structure is reached.

[0030] The movement control unit 312 performs processing to control the movement of the robot arm 27a that moves the nozzle 23 according to the path. The discharge volume control unit 313 controls the pump 21 and valve 24 that pump the mortar, and performs a process to control the amount of mortar discharged from the nozzle 23.

[0031] The pump control unit 316 is a control unit that controls the drive of the pump 21. In this embodiment, the pump control unit 316 is controlled in accordance with the control of the discharge volume control unit 313. The valve control unit 317 is a control unit that controls the drive of the valve 24. This valve control unit 317 controls the supply and exhaust of compressed air to the compressor 25 and the valve 24. The valve control unit 317 is controlled in accordance with the control of the discharge volume control unit 313.

[0032] The arm control unit 318 controls the movement of the arm 27a of the robot 27. This arm control unit 318 also controls the movement of the nozzle 23. Furthermore, the arm control unit 318 controls the arm 27a so that the direction of mortar discharge from the nozzle 23 is always downward during movement.

[0033] (Configuration of creation support server 40) Next, we will describe the configuration of the creation support server 40 as a formation support system. The creation support server 40 shown in Figure 6 is a computer terminal that determines the movement path of the nozzle 23 and the amount of mortar discharged from the nozzle 23. This creation support server 40 includes a control unit 41 and a discharge path storage unit 42. The creation support server 40 is connected to the control unit 30 of the 3D printer 20 and transmits the completed discharge path data to the control unit 30.

[0034] The control unit 41 functions as an acquisition unit 411 and a setting unit 412 by executing a formation support program stored in the memory unit. The acquisition unit 411 acquires the shape of the structure to be formed (frame members (11~13)). The setting unit 412 performs the process of setting each path for forming the structure. In this embodiment, the setting unit 412 sets the movement speed and operation timing of the nozzle 23 in the first layer, intermediate layer, and final layer of the frame members (11-13). Here, the operation timing includes the timing of movement, stopping, and speed change of the nozzle 23, the timing of driving and stopping the pump 21, and the timing of opening and closing the valve 24. For this reason, the setting unit 412 stores the discharge amount of normal mortar in the intermediate layer discharged from the nozzle 23, the volume of the nozzle 23 used for various timing settings, and measured values. In this embodiment, the discharge amount of mortar is set to, for example, approximately 100 liters / hour.

[0035] The discharge path memory unit 42 stores discharge path data for the nozzles 23 that form the structure. This discharge path data is recorded when the set path, the drive timing of the pump 21, nozzles 23 and valves 24, etc., set by the setting unit 412 are determined. The discharge path data includes data on the structure identifier, the path for each stacking number, the movement speed along the path, and the position of the operation timing along the path.

[0036] The structure identifier data area stores data related to identifiers used to identify each structure. The layer count data area records data related to identifiers used to identify the number of layers that make up the structure. Here, for example, the layer count from the bottom layer is used as the identifier.

[0037] The path data area records the path of the nozzle 23 of the 3D printer 20 in this hierarchy. The movement speed data area records data on the movement speed at each point along the path, associated with the location of each point. This movement speed is calculated from the amount of mortar discharged in the intermediate layer from the nozzle 23, the shape of the structure, etc. The operation timing data area records data related to the driving and stopping timings of the pump 21 and valve 24, associated with the position of each point along this path.

[0038] (Discharge path generation process) Next, the discharge path generation process will be explained using Figures 6, 7, and 9. First, the control unit 41 of the creation support server 40 executes the process of acquiring the shape of the structure. Specifically, the acquisition unit 411 of the control unit 41 acquires a drawing of the structure 10 to be formed and acquires the shapes of the frame members (11-13) that are made up by lamination.

[0039] Next, the control unit 41 of the creation support server 40 performs setting processing for the path, movement speed along the path, and operation timing at each level. Specifically, the setting unit 412 of the control unit 41 divides the shape of each frame member (11 to 13) acquired by the thickness (height position) of each layer, and generates the path of the nozzle 23 at each level according to the divided planar shape. Furthermore, the setting unit 412 calculates the movement speed of the nozzle 23 along the generated path.

[0040] In this case, as shown in Figure 7, the setting unit 412 sets the pump stop point Pp1, the valve closing start point Pv1, and the movement stop point Pn1 in the final layer path of each frame member (11-13). Here, the pump stop point Pp1 is the point where the drive of the pump 21 is stopped in the uppermost layer path, which is the final layer. The valve closing start point Pv1 is the point where the closing of the valve 24 is started. The movement stop point Pn1 is the point where the horizontal movement of the nozzle 23 in the formation of this frame member (11-13) is stopped by completing the mortar application process after the valve 24 is closed.

[0041] In this embodiment, the pump stop point Pp1 is set to a position L1 minutes before the valve closing start point Pv1 along the path. This distance L1 is calculated using the pressure drop time D11, which is the time it takes for the mortar pressure to drop to almost zero after the pump 21 that was pressurizing the mortar is stopped, and the movement speed S1 of the nozzle 23. The pressure drop time D11 is, for example, about 6 seconds.

[0042] The valve closing start point Pv1 is the point where valve 24 begins to close so that it completely closes at the end point Pf1 of the final layer. This point is set at a distance L2 minutes before the end point Pf1. Therefore, the distance L2 is calculated using the valve closing time D12, which is the time required for valve 24 to close completely from the start of closing, and the movement speed S1 of nozzle 23. Note that the end point Pf1 is adjacent to the start point Ps1 of the final layer. Furthermore, the valve closing time D12 is, for example, about 3 seconds.

[0043] The stopping point Pn1 is set at a distance L3 minutes along the path from the end point Pf1. This distance L3 is the area where the mortar discharged from the end point Pf1 when the valve 24 is completely closed is layered on the frame members (11-13) following the starting point Ps1. Since no mortar is supplied from the valve 24 to the tip when the valve 24 is completely closed, the discharge amount M1 of mortar forming this distance L3 is the amount of mortar remaining from the tube 55 of the valve 24 to the discharge port 23a of the nozzle 23. Therefore, this distance L3 is calculated by dividing this mortar discharge amount M1 by the movement speed S1 of the nozzle 23. Furthermore, this mortar discharge amount M1 is affected by the position of the valve 24 relative to the nozzle 23, the length of the tube 55 inside the valve 24, etc. For this reason, the mortar discharge amount M1 should be confirmed in advance experimentally or by calculation.

[0044] Furthermore, as shown in Figure 9, when forming the next frame member (13) after the completion of one frame member (12), the nozzle 23 is set to wait for a period of time D2 to elapse after reaching the formation start point Ps2 in the path of the first layer (bottom layer) of this frame member (13).

[0045] This waiting time D2 is the sum of a first waiting time D21, which is the time from when the pump 21 is driven until the valve 24 starts to open, and a second waiting time D22, which is the time from when the valve 24 opens until mortar can be discharged from the nozzle 23. The first waiting time D21 is an experimentally measured value of the pressurization waiting time required for the mortar pumped by the pump 21 to reach the nozzle 23 via the supply unit 22. The second waiting time D22 is the time from when the valve 24 is opened until the mortar is distributed throughout the valve 24 and discharged from the nozzle 23a. This second waiting time D22 is measured experimentally in advance.

[0046] Furthermore, once the nozzle 23 starts moving at the formation start point Ps2, it is moved at a low speed. Here, the low speed is defined as approximately 90% of the speed at which it moves along the path included in the discharge path data. After the low-speed termination point PL2, where the discharge of mortar from the nozzle 23 has stabilized, it is moved at the normal speed (the speed at which it moves along the path included in the discharge path data).

[0047] Next, the control unit 41 of the creation support server 40 performs the storage processing of the discharge route data. Specifically, the setting unit 412 of the control unit 41 assigns a structure identifier, generates discharge route data, and records it in the discharge route storage unit 42. In this case, the setting unit 412 includes in the discharge route data the number of layers stored in the storage device H14, the route corresponding to each layer, the movement speed along the route, and each point corresponding to the operation timing.

[0048] Then, before forming the frame members (11-13), the control unit 41 of the creation support server 40 transmits the ejection path data stored in the ejection path storage unit 42 to the control device 30 of the 3D printer 20. The control unit 31 of the control device 30 stores the acquired ejection path data.

[0049] (Method for forming structure 10) The 3D printer 20 performs the structure formation process using the control unit 31 of the control device 30. Specifically, the layer management unit 311 of the control unit 31 controls the movement control unit 312 and the discharge amount control unit 313 using the stored discharge path data.

[0050] The movement control unit 312 then moves the arm 27a of the robot 27 while discharging mortar from the nozzle 23. In this case, the movement control unit 312 moves the nozzle 23 along the path of the path data corresponding to the number of layers, and changes the movement speed of the nozzle 23 so that it is the movement speed corresponding to each point in the path. Then, the mortar discharging from the nozzle 23 is layered by the 3D printer 20 to the final height, forming the frame members (11-13).

[0051] During this structural formation process, an end start control process is performed when the formation of each frame member (11-13) begins, and an end end end control process is performed when the formation of each frame member (11-13) is completed. Here, as a specific example, we will explain the end termination control process at the end of the formation of the inner frame member 12 and the subsequent end start control process at the start of the formation of the inner frame member 13.

[0052] (End termination control processing) Using Figures 7 and 8, the end termination control process performed by the control unit 31 of the control device 30 at the final layer of the frame member (12) will be explained.

[0053] In this process, first, the control unit 31 of the control device 30 executes a pump drive stop process at the pump stop time T11 (step S11). Specifically, the pump control unit 316 of the control unit 31 stops the drive of the pump 21 at the pump stop point Pp1. In this case, the arm control unit 318 of the control unit 31 moves the nozzle 23 along a path and at a speed based on the discharge path data, in accordance with the instructions of the movement control unit 312.

[0054] Next, the control unit 31 of the control device 30 executes the valve closing start process at the valve closing start time T12 (step S12). Specifically, the valve control unit 317 of the control unit 31 drives the compressor 25 at the valve closing start point Pv1 to supply compressed air to the outer circumference of the tube 55 of the valve 24 via the air supply pipe 26. In this case as well, the arm control unit 318 of the control unit 31 moves the nozzle 23 along a path and at a speed based on the discharge path data. Then, at the arrival time T13, the control unit 31 of the control device 30 determines that the vehicle has reached the end point Pf1 and completely closes the valve (step S13).

[0055] Next, the control unit 31 of the control device 30 executes the sliding process from the arrival time T13 at the end point (step S14). Specifically, the arm control unit 318 of the control unit 31 moves the nozzle 23 to the stopping point Pn1 along the path following the end point Pf1 (the same path used to form the final layer from the starting point Ps1 of the final layer, and the same path used to stack the final layer on top of it). In this case, the arm control unit 318 moves the nozzle 23 at the same speed as the moving speed at the end point Pf1.

[0056] Then, when the nozzle 23 reaches the stopping point Pn1, the control unit 31 of the control device 30 performs a process to separate the nozzle from the formed frame member (step S15). Specifically, the arm control unit 318 of the control unit 31 stops the horizontal movement of the nozzle 23 at the end of movement time T14 when it arrives at the stopping point Pn1, and moves the nozzle 23 above the stopping point Pn1. This separates the discharge port of the nozzle 23 (and the mortar remaining from the discharge port) from the mortar forming the formed frame member (12).

[0057] (End-point start control processing) Next, the end-start control process will be explained using Figures 9 and 10. As shown in Figure 9, the control unit 31 of the control device 30 moves to the starting point Ps2 for forming the next layer (bottom layer) of the inner frame member 13. Specifically, the arm control unit 318 of the control unit 31 moves the nozzle 23, which is separated from the inner frame member 12, from the stopping point Pn1 to the starting point Ps2.

[0058] In this case, as shown in Figure 10, the control unit 31 of the control device 30 executes the pump drive process (step S21). Specifically, the pump control unit 316 of the control unit 31 drives the pump 21 immediately after the nozzle separation process (step S15) is executed if the waiting time D2 is shorter than the travel time of the nozzle 23 from the stopping point Pn1 to the formation start point Ps2. If the travel time is longer than the waiting time D2, the pump 21 is driven so that the waiting time D2 elapses when the nozzle 23 reaches the formation start point Ps2. That is, the pump 21 is driven at a time 2 minutes before the arrival time of the nozzle 23 at the formation start point Ps2.

[0059] Next, the control unit 31 of the control device 30 executes the valve opening start process after a first waiting time D21 has elapsed since the pump 21 was started (step S22). Specifically, the valve control unit 317 of the control unit 31 deflates the tube 55 of the valve 24 by discharging the compressed air around the tube 55, thereby opening the flow path.

[0060] Subsequently, the control unit 31 of the control device 30 executes a process to start the movement of the nozzle at a low speed at time T21, after the waiting time D2 has elapsed since the start of the pump 21's operation (after the first waiting time D21 and the second waiting time D22 have elapsed) (step S23). Specifically, the arm control unit 318 of the control unit 31 controls the arm 27a of the robot 27 so that the nozzle 23 moves based on the path and speed of the discharge path data. In this case, the arm control unit 318 moves the nozzle 23 at a low speed (approximately 90% of the speed of the discharge path data) until the low-speed termination point PL2. Then, after reaching the low-speed termination point PL2 at time T22, the control unit 31 of the control device 30 performs the nozzle movement process at normal speed (step S24). Specifically, the arm control unit 318 of the control unit 31 controls the arm 27a so that the nozzle 23 moves at normal speed (speed of discharge path data).

[0061] After the inner frame members 12 and 13 are completed, the outer frame member 11 is formed around the outer periphery of the inner frame members 12 and 13. Then, after the frame members (11-13) have hardened, the frame members (11-13) are used as formwork to fill the space between the outer frame member 11 and the inner frame members 12 and 13 with fiber-reinforced concrete material. After this fiber-reinforced concrete material has hardened, the internal structure 15 is integrated with the frame members (11-13), and the structure 10 is completed.

[0062] (action) In this embodiment, a valve 24 is provided on the supply section 22 side of the nozzle 23. By closing this valve 24 over time, the amount of mortar discharged from the nozzle 23 can be gradually reduced, thereby suppressing the sudden discharge of mortar.

[0063] According to this embodiment, the following effects can be obtained. (1) The 3D printer 20 of this embodiment is provided with a valve 24 between the nozzle 23 and the supply unit 22. A pinch valve is used as the valve 24, which closes when the tube 55 expands. This allows the valve 24 to be closed slowly, so that the amount of mortar discharged can be gradually reduced. Therefore, when stopping the discharge of mortar, it is difficult for a large local pressure to be applied to the mortar, and a sudden discharge of mortar can be suppressed.

[0064] (2) In this embodiment, the 3D printer 20 starts closing the valve 24 when the nozzle 23 has advanced a distance L1 after the pump 21 has been stopped (step S11). As a result, the valve 24 is closed after the pressure of the mortar in the supply unit 22 has decreased, so that a large pressure is not applied to the valve 24 when it is closed.

[0065] (3) In this embodiment, a pinch valve is used as the valve 24, which closes when the tube 55 expands. This allows the valve 24 to be opened and closed smoothly, even if the material hardens over time.

[0066] (4) In this embodiment, the 3D printer 20 begins closing the valve 24 at the closing start time T12 so that the valve 24 is completely closed at the end point Pf1 of the nozzle 23. This allows the mortar to be discharged at the required discharge amount up to the end point Pf1.

[0067] (5) The 3D printer 20 of this embodiment performs a mortar application process after the valve 24 is completely closed (step S14). In this process, the nozzle 23 is moved along the path of the final layer, and the mortar discharged from the nozzle 23 is applied. This allows the path to be formed using mortar that continues to be discharged even after the pump 21 is stopped and the valve 24 is closed.

[0068] (6) In this embodiment, when forming the first layer, the 3D printer 20 moves the nozzle 23 after a waiting time D2 has elapsed from the start of operation of the pump 21. This ensures that the valve opens after the mortar has been sufficiently pressurized, thereby ensuring a sufficient amount of mortar is discharged from the nozzle 23.

[0069] (7) In this embodiment, the 3D printer 20 moves the nozzle 23 at a low speed from the formation start point Ps2 to the low-speed end point PL2 in the first layer. This makes it possible to form the first layer to the desired size even if the amount of mortar discharged at the start of discharge is small.

[0070] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. In the above embodiment, the distances L1 and L2 were set so that the valve 24 would be completely closed at the end point Pf1 of the final layer. Alternatively, the closing of the valve 24 may be started at the end point Pf1 of the final layer.

[0071] Specifically, as shown in Figure 11, the pump 21 is stopped at time T31 at the pump stop point Pp2, which is a distance L1 minute before the end point Pf1 of the final layer. Then, at time T32, when the pump reaches the end point Pf1, the valve 24 begins to close. The valve 24 is then completely closed at time T33, which is a distance L2 minutes ahead of the end point Pf1. Furthermore, a sliding process is performed from time T33 to time T34.

[0072] In the above embodiment, the 3D printer 20 performed the following actions during the end-of-processing: stopping the pump 21 and starting the valve 24 to close in the final layer. If the structure to be formed is small, the pump may be stopped and the valve 24 to close in a layer below the final layer.

[0073] In the above embodiment, a pinch valve was used as the valve 24 of the 3D printer 20, in which a flexible tube 55 expands with the supplied compressed air to close the valve. The pinch valve used for valve 24 is not limited to this configuration. Any valve that can withstand repeated use is acceptable, depending on the properties of the material being molded. For example, it is possible to use a pinch valve of the type that compresses the flow path tube by applying pressure from the surroundings when closing the valve.

[0074] In the above embodiment, the end-of-discharge control process at the end of discharge, which sets the discharge amount of mortar from the structure to "0", and the end-of-discharge start control process at the start of discharge, which changes the discharge amount of mortar from "0" to a predetermined amount, were described. The change in discharge amount is not limited to cases where it is reduced from the required amount to "0" or increased from "0" to the required amount. For example, problems can be suppressed when changing the discharge amount from a first set amount to a second set amount by controlling the pump or valve. In the above embodiment, the arm control unit 318 moved the nozzle 23 at a low speed (approximately 90% of the speed in the discharge path data) from the formation start point Ps2 to the low-speed end point PL2. Alternatively, the control unit 41 of the creation support server 40 may store a low speed of 90% of the calculated movement speed from the formation start point Ps2 to the low-speed end point PL2 in the discharge path data. The arm control unit 318 may then move the nozzle 23 from the formation start point Ps2 to the low-speed end point PL2 at the movement speed in the stored discharge path data.

[0075] In the above embodiment, mortar was used as the molding material for forming the frame members (11-13). The molding material that constitutes the structure is not limited to mortar; any material that has the fluidity to be discharged from the nozzle 23 and the hardness to be stacked may be used, such as synthetic resin.

[0076] In the above embodiment, the control unit 31 of the control device 30 of the 3D printer 20 controls the driving and stopping of the pump 21, the opening and closing of the valve 24, and the movement of the nozzle 23. These controls may be performed in response to instructions from an operator.

[0077] Next, the technical concepts that can be understood from the above embodiments and alternative examples are described below. (a) The structure forming system according to claim 5, characterized in that the control unit opens the valve, and after a second waiting period has elapsed in which the molding material has spread throughout the nozzle and the molding material has been discharged from the nozzle outlet, moves the nozzle to form the structure.

[0078] (b) The structure forming system according to 5 or (a), characterized in that the control unit opens the valve and then slows down the movement speed of the nozzle, which moves while discharging the molding material, to a design movement speed. [Explanation of Symbols]

[0079] D11... Pressure drop time, D12... Time required to close the valve, D2... Waiting time, D21... First waiting time, D22... Second waiting time, E1... Cavity, L1, L2, L3... Distance, M1... Discharge volume, NL1... Length, Pf1... End point, PL2... Low speed end point, Pn1... Movement stop point, Pp1, Pp2... Pump stop point, Ps1... Start point, Ps2... Formation start point, Pv1... Valve closing start point, S1... Movement speed, T11... Pump stop time, T12... Valve closing start time, T13... End point arrival time, T14... Movement end time, T21, T22, T31, T32, T33, T34... Time, 10... Structure, 11... Outer frame member, 12 ,13...Inner frame member, 15...Internal structure, 20...3D printer, 21...Pump, 22...Supply unit as connection part, 23...Nozzle, 23a...Discharge port, 24...Valve, 25...Compressor, 26...Air supply pipe, 27...Robot, 27a...Arm, 28...Mounting part, 30...Control device, 31,41...Control unit, 40...Creation support server, 42...Discharge path storage unit, 51...Housing, 51a,51b...Flange, 55...Tube, 311...Layer management unit, 312...Movement control unit, 313...Discharge volume control unit, 316...Pump control unit, 317...Valve control unit, 318...Arm control unit, 411...Acquisition unit, 412...Setting unit.

Claims

1. A system for forming a laminated structure by stacking layers of cement-based material discharged from a discharge port facing downwards of the nozzle while moving the nozzle, A control unit for controlling the stacking, A pump for supplying the cement-based material to the nozzle, The system includes a valve provided between the nozzle and the connection part connected to the pump, The valve is a pinch valve that closes by blocking the flow path with a flexible tube. The control unit, While moving the nozzle, At the time of arrival at the endpoint, when the nozzle reaches the design endpoint of the structure as determined by the shape of the structure and the movement speed and operating timing of the nozzle, the valve is to be completely closed. The valve is to be started to close at the time of start of valve closing, which is before the time required for the valve to start closing and for the tube to completely close by blocking the flow path, and before the time required for the supply of compressed air to the outer circumference of the tube to start closing. From the valve closing start time, the pump is stopped at the pump stop time before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump. From the time of arrival at the aforementioned endpoint until the time of completion of movement, when the amount of cement-based material remaining from the tube to the nozzle outlet, which was calculated in advance by experiment or calculation, is finished to be discharged, the nozzle is moved along the portion of the structure that is continuous with the endpoint. A structure forming system characterized by moving the nozzle above the structure at the time the movement is completed, thereby separating the nozzle from the structure.

2. A system for forming a laminated structure by stacking layers formed of cement-based material discharged from a discharge port facing downward of the nozzle while moving the nozzle, A control unit for controlling the stacking, A pump for supplying the cement-based material to the nozzle, The system includes a valve provided between the nozzle and the connection part connected to the pump, The valve is a pinch valve that closes by blocking the flow path with a flexible tube. The control unit, While moving the nozzle, From the time the nozzle reaches the design end point of the structure, which is determined from the shape of the structure and the movement speed and operating timing of the nozzle, to the time the pump stops before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump, the pump is stopped. At the time of arrival at the aforementioned terminal, the valve is closed. From the time of arrival at the aforementioned endpoint, from the time after the required time for valve closing has elapsed from the start of valve closing until the tube completely closes by blocking the flow path, until the time of completion of movement, when the amount of cement-based material remaining from the tube to the nozzle outlet, which was calculated in advance by experiment or calculation, is finished to be discharged, the nozzle is moved along the portion of the structure that is continuous with the endpoint. A structure forming system characterized by moving the nozzle above the structure at the time the movement is completed, thereby separating the nozzle from the structure.

3. The control unit, After separating the nozzle from the structure, the nozzle is moved to the starting point of formation of a structure other than the aforementioned structure, A structure forming system according to claim 1 or 2, characterized in that, based on experimentally measured values, the pump is driven such that the waiting time from opening the valve after the pressurized waiting time required for the cement-based material pumped by the pump to reach the nozzle, until the cement-based material is discharged from the nozzle outlet due to the cement-based material spreading throughout the valve, ends after the material arrives at the formation start point.

4. A method for forming a laminated structure by using a structure forming system to stack layers formed from a molding material extruded from a discharge port facing downwards of the nozzle while moving the nozzle, The aforementioned structural forming system is A pump for pressurizing cement-based material to the nozzle, The system includes a valve provided between the nozzle and the connection part connected to the pump, The valve is a pinch valve that closes by blocking the flow path with a flexible tube. While moving the nozzle, At the time of arrival at the endpoint, when the nozzle reaches the design endpoint of the structure as determined by the shape of the structure and the movement speed and operating timing of the nozzle, the valve is to be completely closed. The valve is to be started to close at the time of start of valve closing, which is before the time required for the valve to start closing and for the tube to completely close by blocking the flow path, and before the time required for the supply of compressed air to the outer circumference of the tube to start closing. From the valve closing start time, the pump is stopped at the pump stop time before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump. From the time of arrival at the aforementioned endpoint until the time of completion of movement, when the amount of cement-based material remaining from the tube to the nozzle outlet, which was calculated in advance by experiment or calculation, is finished to be discharged, the nozzle is moved along the portion of the structure that is continuous with the endpoint. A method for forming a structure, characterized in that, at the time the movement is completed, the nozzle is moved above the structure, thereby separating the nozzle from the structure.

5. A method for forming a laminated structure by using a structure forming system to stack layers formed from a molding material extruded from a discharge port facing downward of the nozzle while moving the nozzle, The aforementioned structural forming system is A pump for pressurizing cement-based material to the nozzle, The system includes a valve provided between the nozzle and the connection part connected to the pump, The valve is a pinch valve that closes by blocking the flow path with a flexible tube. While moving the nozzle, From the time the nozzle reaches the design end point of the structure, which is determined from the shape of the structure and the movement speed and operating timing of the nozzle, to the time the pump stops before the pressure drop time that reduces the pressure of the cement-based material pressurized by the pump, the pump is stopped. At the time of arrival at the aforementioned terminal, the valve is closed. From the time of arrival at the aforementioned endpoint, from the time after the required time for valve closing has elapsed from the start of valve closing until the tube completely closes by blocking the flow path, until the time of completion of movement, when the amount of cement-based material remaining from the tube to the nozzle outlet, which was calculated in advance by experiment or calculation, is finished to be discharged, the nozzle is moved along the portion of the structure that is continuous with the endpoint. A method for forming a structure, characterized in that, at the time the movement is completed, the nozzle is moved above the structure, thereby separating the nozzle from the structure.

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