Spray-coating device for resin additive using unmanned air vehicle

Abstract

To provide a device that can safely and surely spray-coat a surface of a construction with polyurethane resin or polyurea resin whose melting point is above an ordinary temperature as a raw material, in a wide work range, in a short preliminary work period of time.SOLUTION: A spray-coating device D, which spray-coats a surface of a construction with polyurethane resin or polyurea resin using an unmanned air vehicle 1, is provided with: the unmanned air vehicle 1; two or more replaceable containers, loaded on the unmanned air vehicle 1, which respectively store first liquid comprised of polyisocyanate compounds and second liquid comprised of polyol compounds or polyamine compounds; a moisturizing member 3 that moisturizes the containers; an actuator 5 that supplies the first liquid and the second liquid stored in the containers to a static mixer 4; and a nozzle 6 that sprays mixed liquid mixed with the static mixer 4 to the surface of the construction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for spray coating resins, polymer cements, etc. onto the surface of a structure using an unmanned aerial vehicle. [Background technology]

[0002] The surfaces of structures such as wind turbine blades and towers inevitably deteriorate over time due to continued exposure to wind and rain, and are damaged by collisions with birds and lightning strikes. Furthermore, viaduct girders, bridge piers, and a wide variety of other concrete structures are prone to cracks, lifting and peeling, and corrosion of rebar due to neutralization, salt damage, frost damage, fatigue, and weathering. For this reason, structure surfaces are inspected periodically. If inspections reveal peeling protective film on the structure's surface or rust on metal parts, the peeling or rusted areas are removed, and then repairs are carried out, such as applying a resin or injecting it into the cracked areas, and then forming a protective film on the surface.

[0003] Repairs using resin coatings are usually carried out by workers, which makes them dangerous and difficult to work with, especially at high altitudes. In addition, the preparatory work, such as assembling scaffolding or installing suspension gondolas, makes the work long and expensive.

[0004] Therefore, for example, Patent Document 1 proposes a device in which a support main body with a discharge part is suspended from a hanging body (unmanned aerial vehicle), and paint sent from the ground via a hose is sprayed onto the wall surface of a structure from the discharge part. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-83932 Summary of the Invention [Problem to be solved by the invention]

[0006] In the technology proposed in Patent Document 1, the coating material is delivered from the ground via a hose, so the working range is limited by the length of the hose. Also, when using a coating material with a melting point above room temperature, the hose needs to be heated and kept warm to prevent the coating material from solidifying, making it difficult to lengthen the hose in practice.

[0007] Therefore, the object of the present invention is to provide an apparatus that can safely and reliably spray paint polyurethane resin or polyurea resin onto the surface of a structure, using raw materials with a melting point above room temperature, with a short preparation work period and over a wide work area. [Means for solving the problem]

[0008] One aspect of the spray coating device for structural surfaces according to the present invention, which achieves the above-mentioned object, is a device for spray coating polyurethane resin or polyurea resin onto the surface of a structure using an unmanned aerial vehicle, characterized in that it comprises an unmanned aerial vehicle, two or more interchangeable containers mounted on the unmanned aerial vehicle, each of which stores a first liquid consisting of a polyisocyanate compound and a second liquid consisting of a polyol compound or a polyamine compound, a heat-insulating member for keeping the containers warm, an actuator for supplying the first liquid and the second liquid stored in the containers to a mixer, and a nozzle for spraying the mixed liquid mixed in the mixer onto the surface of the structure.

[0009] In the spray coating device having the above configuration, it is preferable that the actuator has a pressure accumulator filled with compressed gas, a cylinder to which compressed gas is supplied from the pressure accumulator, and a piston arranged to be slidable in the axial direction within the cylinder, and when compressed gas is supplied to the cylinder, the piston slides in the axial direction within the cylinder and the rod of the piston protrudes outward from the cylinder, pushing out and supplying the first liquid and the second liquid within the container to the mixer.

[0010] In the spray coating device having the above configuration, it is preferable that the unmanned aerial vehicle further includes a camera.

[0011] In the spray coating apparatus having the above configuration, the mixer is preferably a static mixer. [Effects of the Invention]

[0012] The spray coating device of the present invention can safely and reliably spray coating the surface of a structure with polyurethane resin or polyurea resin, which uses raw materials with a melting point above room temperature, over a wide work area with a short preparation period. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view showing an embodiment of a spray coating device according to the present invention. [Figure 2] FIG. 2 is a top view of the spray coating device of FIG. [Figure 3] FIG. 2 is a schematic diagram of the actuator, container, static mixer, nozzle, and cover of the spray coating device shown in FIG. 1. [Figure 4] 1 is a block diagram of a spray coating device according to the present invention; [Figure 5] 4 is a flowchart showing an example of control of the spray coating device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the spray coating device of the present invention will be described in more detail with reference to the drawings, but the present invention is not limited to these embodiments.

[0015] 1 and 2 show a side view and a top view of one embodiment of a spray coating device according to the present invention. The spray coating device D shown in these figures includes an unmanned aerial vehicle 1, two containers 2a and 2b (shown in FIG. 3) covered with a thermal insulation member 3 mounted on the unmanned aerial vehicle 1, a static mixer (mixer) 4 that mixes a first liquid L1 and a second liquid L2 (shown in FIG. 3) stored in the containers 2a and 2b, respectively, an air-operated actuator 5 that extrudes and supplies the first liquid L1 and the second liquid L2 from the containers 2a and 2b to the static mixer 4, a nozzle 6 attached to the end of the static mixer 4, and a cover member 7 attached to the nozzle 6. Each component of the spray coating device D will be described below.

[0016] (Unmanned aerial vehicle) One of the major features of the present invention is the use of an unmanned aerial vehicle 1 as a means of transportation for spray painting repair areas of a structure. This eliminates the need for preparatory work such as assembling scaffolding or setting up a hanging gondola, significantly shortening the work time compared to conventional methods. There are no particular limitations on the unmanned aerial vehicle 1 that can be used in the present invention, and commercially available vehicles can be used as long as they can be equipped with containers 2a and 2b (shown in Figure 3) and actuator 5, which will be described later. The unmanned aerial vehicle 1 shown in Figure 1 includes a main body 10, four rod-shaped support members 12a-12d extending outward at approximately equal angular intervals from the outer periphery of the main body 10 in a plan view, four rotary motors 13a-13d (hereinafter sometimes collectively referred to as "rotary motors 13") provided at the tip of each of the four support members 12a-12d with their rotation axes aligned vertically, four rotors 14a-14d (hereinafter sometimes collectively referred to as "rotor 14") attached to the rotation shafts of each of the four rotary motors 13, a control unit 15 (shown in Figure 4) that controls the rotation of the four rotary motors 13, a communication unit 16 (shown in Figure 4), and a power source 17 (shown in Figure 4). The main body 10 houses the control unit 15, the communication unit 16, and the power source 17. Furthermore, in this embodiment, the unmanned aerial vehicle 1 is a so-called quadcopter, but is not limited to this and may be a helicopter or other multicopters with one, three, six, or eight rotors 14. If the storage battery cannot sufficiently supply the power required to power the rotors of the unmanned aerial vehicle, the unmanned aerial vehicle can be hung from a power cable and supplied with power from the ground. If the rotors are powered by an engine, a generator may be installed on the unmanned aerial vehicle to supply power from the generator.

[0017] The rotation of the rotors 14 generates buoyancy for the unmanned aerial vehicle 1. The rotation speed of each rotor 14 is individually controlled by each rotary motor 13 using a control signal from the control unit 15. This enables the unmanned aerial vehicle 1 to move forward, backward, left, right, up, down, turn, hover, and so on.

[0018] The unmanned aerial vehicle 1 flies under remote instruction control by the pilot, with the communication unit 16 receiving instruction signals and the control unit 15 controlling the drive of the multiple rotary motors 13. Alternatively, the unmanned aerial vehicle 1 may fly by determining its current position using signals from a GPS (Global Positioning System) or signals from a ground station. Furthermore, the unmanned aerial vehicle 1 may be equipped with sensors such as an acceleration sensor, angular velocity sensor, air pressure sensor, altitude sensor, wind direction and speed sensor, and gyro sensor (not shown) to ensure stable flight. Furthermore, the unmanned aerial vehicle 1 may be equipped with pitch control of the rotor blades to improve the stability and accuracy of position control.

[0019] As shown in Fig. 1, a camera 8 is rotatably mounted on the underside of a main body 10. Four rod-shaped legs 9a to 9d are attached to the main body 10 facing downward. A base 90 is fixed to the middle of the four legs 9a to 9d in the vertical direction. An insulator 3 containing containers 2a and 2b, which will be described later, and an actuator 5 are attached to the top surface of the base 90.

[0020] The photographing direction of camera 8 is controlled based on commands from control unit 15, and the camera 8 photographs the state of the structure surface before and / or after spray painting. The spray painting conditions can also be optimized based on the state of the structure surface before and / or after spray painting photographed by camera 8.

[0021] (Containers, heat-insulating materials) As shown in FIG. 3, two containers 2a and 2b are mounted on the unmanned aerial vehicle 1. Container 2a is filled with a polyisocyanate compound as a first liquid L1, and container 2b is filled with a polyol compound or polyamine compound as a second liquid L2. The two containers 2a and 2b have identical cylindrical shapes and are partially joined together side-by-side for handling as a single unit. The axial ends of the two containers 2a and 2b are connected to a common supply port 22. The rear walls 21a and 21b at the axial rear ends of the two containers 2a and 2b are liquid-tight and movable axially. As described below, the rods 54a and 54b of the actuator 5 protrude, moving the rear walls 21a and 21b of the containers 2a and 2b toward their axial ends, and the first liquid L1 and the second liquid L2 are extruded from the containers 2a and 2b and supplied to the static mixer 4. The containers 2a and 2b are replaceable, and when the first liquid L1 and the second liquid L2 in the containers 2a and 2b run out due to use, they are replaced with new ones. Note that the two containers 2a and 2b may not be joined together but may be separate.

[0022] The containers 2a, 2b filled with the first liquid L1 and the second liquid L2 are heated by a heater (not shown) on the ground before being loaded onto the unmanned aerial vehicle 1. Once the temperature reaches a set temperature (e.g., 75°C), the containers are kept warm and are then loaded onto the unmanned aerial vehicle 1 immediately before flight. Because the temperature inside the containers 2a, 2b is affected by the outside air temperature, the outer periphery of the containers 2a, 2b is covered with a heat-insulating member 3. The containers 2a, 2b may be loaded onto the unmanned aerial vehicle 1 while covered with the heat-insulating member 3, or the heat-insulating member 3 may be attached to the attachment portion of the containers 2a, 2b on the unmanned aerial vehicle 1. In consideration of the operation time, in addition to the heat-insulating member 3, a heating member such as a heater H (shown in FIG. 4) may be attached around the containers 2a, 2b.

[0023] When a polyol compound is used as the second liquid L2, it reacts with the polyisocyanate compound in the first liquid L1 to form a polyurethane resin, which is spray-coated onto the surface of the structure. When a polyamine compound is used as the second liquid L2, it reacts with the polyisocyanate compound in the first liquid L1 to form a polyurea resin, which is spray-coated onto the surface of the structure.

[0024] The polyisocyanate compound has two or more isocyanate groups in one molecule, and examples of low molecular weight isocyanate compounds that can be used include diphenylmethane-4,4'-diisocyanate (MDI), carbodiimide-modified diphenylmethane diisocyanate (liquid MDI), polymethylene polyphenylisocyanate (crude MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate, and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI).

[0025] The polyol compound has two or more alcoholic hydroxyl groups in one molecule, and examples thereof include polyether polyol, polyester polyol, and polytetramethylene glycol.

[0026] The polyamine compound has an amino group, and examples of the polyamine compound that can be used include aliphatic polyamines such as triethylenetetramine, aromatic polyamines such as metaphenylenediamine, and alicyclic polyamines such as isophoronediamine.

[0027] (Static mixer) The static mixer 4 has a cylindrical member 41 and an element 42, such as a curved plate, inserted into the cylindrical member 41. As the first liquid L1 and the second liquid L2 pass through the static mixer 4, they are mixed by actions such as division and merging, local shearing, stretching, and folding. The mixer used in the present invention is not limited to the static mixer 4, and any conventionally known mixer can be used. However, the use of a static mixer 4 is preferable because of its simple structure and the lack of power required. The static mixer 4 is preferably replaceable, and is preferably replaced with a new one after each spray coating operation. In other words, it is preferable to replace the static mixer 4 at the same time as replacing the containers 2a and 2b.

[0028] (nozzle) The nozzle 6 sprays the mixed liquid mixed in the static mixer 4 onto the surface of the structure. Specifically, the nozzle 6 mixes the mixed liquid discharged from the static mixer 4 with air sent from the pressure accumulator 51 and sprays the mixture. In this embodiment, the spray shape of the mixed liquid is conical, but this is not limited to this and it may be a square pyramid, a spiral, a line, or the like. The nozzle 6 is detachably attached to the axial tip of the static mixer 4. As mentioned above, the static mixer 4 is replaced together with the used containers 2a and 2b, and it is preferable to replace the nozzle 6 in the same manner.

[0029] (actuator) Fig. 3 shows a schematic diagram of the actuator 5. The actuator 5 shown in Fig. 3 extrudes and supplies the first liquid L1 and the second liquid L2 stored in the containers 2a and 2b to the static mixer 4. The actuator 5 has a pressure accumulator 51 filled with compressed air, a cylinder 52 to which compressed gas is supplied from the pressure accumulator 51, and a piston 53 provided within the cylinder 52 so as to be able to slide in the axial direction. An on-off valve 55, a pressure reducer 56, and a flow rate control valve 57 are provided between the pressure accumulator 51 and the cylinder 52. A branch pipe is also provided between the pressure reducer 56 and the flow rate control valve 57, and air at a predetermined pressure is also sent to the nozzle 6.

[0030] The pressure of the air filled in the pressure accumulator 51 is determined appropriately based on the spray time of the mixed liquid sprayed from the nozzle 6, and is usually in the range of 1 MPa to 5 MPa. The pressure after adjustment by the pressure reducer 56 is determined appropriately based on the spray speed, spray amount, and the like, and is usually in the range of 0.1 MPa to 1 MPa.

[0031] When air adjusted to a predetermined pressure by a pressure reducer 56 is supplied from the pressure accumulator 51 to the cylinder 52, the piston 53 slides axially forward within the cylinder 52, causing the rods 54a and 54b of the piston 53 to protrude axially forward from the cylinder 52, moving the rear walls 21a and 21b of the containers 2a and 2b axially forward. This causes the first liquid L1 and the second liquid L2 in the containers 2a and 2b to be pushed out and supplied to the static mixer 4.

[0032] (Cover member) The cover member 7 is intended to prevent the mixed liquid sprayed from the nozzle 6 from being disturbed by the airflow caused by the rotor 14 of the unmanned aerial vehicle 1. The cover member 7 is detachably attached to the nozzle 6. The shape of the cover member 7 may be determined appropriately according to the spray shape of the mixed liquid. For example, if the spray shape of the mixed liquid is conical as shown in Figures 1 and 2, the shape of the cover member 7 should also be conical. The cover member 7 may come into contact with the surface of the structure. In other words, the cover member 7 may cover the entire flight path of the mixed liquid from the nozzle 6 until it reaches the surface of the structure. A flexible material is preferred for the cover member 7.

[0033] 4 shows a block diagram of a spray painting device D according to one embodiment of the present invention. The spray painting device D has a communication unit 16 that receives remote instructions from the pilot of the unmanned aerial vehicle 1 and transmits images captured by the camera 8 to a remotely controlled device (not shown), and a control unit 15 that controls the drive of the rotary motor 13 and the opening and closing of the on-off valve 55 for supplying compressed air based on the instruction information received from the pilot.

[0034] (Spray painting operation) Figure 5 shows a flowchart illustrating an example of control of the spray painting device D according to the present invention. Under remote instructions from the pilot, the unmanned aerial vehicle 1 flies from a ground base to the portion of the structure surface that needs to be spray painted for repair (step S101). Specifically, the pilot inspects the structure surface for peeling paint, rust on metal parts, cracks or peeling on the concrete surface, etc. while watching the video sent from the camera 8 mounted on the unmanned aerial vehicle 1. Alternatively, if the portion to be repaired has been identified in a prior inspection and its location information has been input, the unmanned aerial vehicle 1 flies to the identified location using a GPS system or the like.

[0035] When the unmanned aerial vehicle 1 reaches the portion to be repaired on the surface of the structure, the unmanned aerial vehicle 1 performs a hovering operation so that the mixed liquid from the nozzle 6 is spray-painted onto the repaired portion (step S102). Then, the on-off valve 55 is opened, and the air supplied from the pressure accumulator 51 is reduced to a predetermined pressure by the pressure reducer 56. The reduced-pressure air is then supplied to the cylinder 52 of the actuator 5 and the nozzle 6. When air is supplied to the cylinder 52, the piston 53 inside the cylinder 52 moves forward, and the two rods 54a, 54b connected to the piston 53 also move forward. The two rods 54a, 54b then move the rear walls 21a, 21b of the two containers 2a, 2b forward, and the first liquid L1 and the second liquid L2 inside the two containers 2a, 2b are pushed out into the static mixer 4.

[0036] The first liquid L1 and the second liquid L2 are mixed while passing through the static mixer 4 and are supplied to the nozzle 6. Then, the mixed liquid is sprayed outward from the tip of the nozzle 6 together with air supplied from the pressure accumulator 51 in the nozzle 6 (step S103).

[0037] While the mixed liquid is being sprayed from the nozzle 6, the unmanned aerial vehicle 1 is automatically or remotely controlled so that the spray-coated film on the repaired part has a desired film thickness. The film thickness of the spray-coated film on the repaired part is determined by the spray coating amount V (mm 3 / s) and spray area A (mm 2 / s) and the quotient V / A (mm). The spray coating volume of the mixed liquid V (mm3 / s) is determined by the amount of air supplied to the cylinder per unit time. The amount of air supplied to the cylinder per unit time can be adjusted in advance. The spray area A (mm 2 / s) is determined by the spray shape from the nozzle (including the spread angle), the distance between the nozzle and the part to be repaired, and the travel speed of the unmanned aerial vehicle 1. Therefore, the unmanned aerial vehicle 1 is controlled so that the nozzle flies at a predetermined distance from the part to be repaired and at a predetermined travel speed so that the spray paint film on the part to be repaired has the desired film thickness.

[0038] Next, it is determined whether the first liquid L1 or the second liquid L2 has been consumed (step S104). If it is determined that the first liquid L1 or the second liquid L2 has been consumed before the spray coating of the mixed liquid onto the repair area is completed ("Y" in step S104), the spray coating operation is temporarily terminated. The unmanned aerial vehicle 1 returns to the ground base and replaces the empty container with a new one. At this time, the static mixer and nozzle are also replaced with new ones. Thereafter, the unmanned aerial vehicle 1 flies again to the repair area and resumes spray coating (steps S101 to S103).

[0039] On the other hand, if it is determined that the first liquid L1 or the second liquid L2 has not been consumed ("N" in step S104), it is then determined from the image from the camera whether spray painting of the repaired area has been completed (step S105). If spray painting of the mixed liquid on the repaired area has not been completed ("N" in step S105), spraying of the mixed liquid continues until spray painting of the repaired area is completed.

[0040] In this embodiment, even if the first liquid L1 and the second liquid L2 remain in the container, the drone returns to the ground base once the refilled area has been spray-painted, replaces the container with a new one, and then flies to the next repair area. This is because when the first liquid L1 and the second liquid L2 mix, they react and solidify immediately, which causes the supply port, static mixer, and nozzle of the container to become clogged during the flight to the next repair area.

[0041] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described modified examples may be combined as appropriate. [Industrial Applicability]

[0042] The spray coating device according to the present invention makes it possible to spray coat the surface of a structure safely and reliably with a short preparation period. [Explanation of symbols]

[0043] 1 unmanned aerial vehicle 2a,2b container 3. Thermal insulation materials 4. Static mixer 5 Actuators 6 nozzles 7 Cover 8. Camera 51 Accumulator 52 cylinders 53 Piston 54a, 54b Rod D. Spray painting equipment H heater L1 1st liquid L2 2nd liquid

Claims

1. An apparatus for spray painting a polyurethane resin or a polyurea resin on a surface of a structure using an unmanned aerial vehicle, Unmanned aerial vehicles and two or more replaceable containers each storing a first liquid comprising a polyisocyanate compound and a second liquid comprising a polyol compound or a polyamine compound, the containers being mounted on the unmanned aerial vehicle; A heat insulating member that keeps the container warm; an actuator that supplies the first liquid and the second liquid stored in the container to a mixer; a nozzle for spraying the mixed liquid mixed in the mixer onto the surface of the structure; A spray coating device comprising:

2. The actuator a pressure accumulator filled with compressed gas; a cylinder to which compressed gas is supplied from the pressure accumulator; a piston provided in the cylinder so as to be slidable in the axial direction, 2. The spray coating device of claim 1, wherein when compressed gas is supplied to the cylinder, the piston slides axially within the cylinder, causing the piston rod to protrude outward from the cylinder and push out and supply the first liquid and second liquid in the container to the mixer.

3. 3. The spray coating apparatus according to claim 1, wherein the mixer is a static mixer.

4. 3. The spray coating device according to claim 1, further comprising a camera.

5. 3. The spray coating device according to claim 1, further comprising a cover member for covering an outer periphery of the mixed liquid sprayed from the nozzle.

Images