Unmanned aerial vehicle (UAV) for spray coating resin materials

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 painting a resin agent, a polymer cement, etc. onto the surface of a structure by means of an unmanned aircraft.

Background Art

[0002] The surfaces of structures such as the blades and towers of wind power generation devices are inevitably subject to aging due to continuous exposure to wind and rain, damage due to collisions with birds, lightning strikes, etc. In addition, the girders, piers of elevated bridges, and various concrete structures also crack, flake, peel, and corrode due to carbonation, salt damage, freezing damage, fatigue, weathering, etc. Therefore, the surfaces of structures are regularly inspected. If peeling of the protective film on the surface of the structure or rust on the metal part is found during the inspection, after removing the peeled part of the protective film and the part where rust has occurred, application of a resin agent, injection into the cracked part, etc. are carried out, and further repair is performed to form a protective film on the surface.

[0003] Repair by application of a resin agent is usually carried out by workers, so it is particularly dangerous and the workability is poor in the case of high places. In addition, the work period including preparation work such as erection of scaffolding or installation of a suspended gondola is long and the cost is high.

[0004] Therefore, for example, in Patent Document 1, there is proposed an apparatus in which a support main body provided with a discharge part is suspended by a suspended body (unmanned aircraft), and a coating agent sent from the ground through a hose is spray painted onto the wall surface of a structure from the discharge part.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the technology proposed in Patent Document 1, the paint is delivered from the ground via a hose, so the working range is limited by the length of the hose. Furthermore, when using a paint with a melting point above room temperature, it is necessary to heat and maintain the temperature of the hose to prevent the paint from solidifying, making it difficult to extend the hose in practical use.

[0007] Therefore, the object of the present invention is to provide an apparatus that can safely and reliably spray-coat the surface of structures with polyurethane resin or polyurea resin, which uses raw materials with a melting point of room temperature or higher, within a short preparation period and over a wide work area. [Means for solving the problem]

[0008] One embodiment of the spray coating apparatus for structural surfaces according to the present invention, which achieves the above objective, is an apparatus for spray coating a polyurethane resin or polyurea resin onto a structural surface using an unmanned aerial vehicle, characterized by comprising: an unmanned aerial vehicle; two or more replaceable containers mounted on the unmanned aerial vehicle, each storing a first liquid made of a polyisocyanate compound and a second liquid made of a polyol compound or 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 from the mixer onto the structural surface.

[0009] In the spray painting apparatus with the above configuration, it is preferable that the actuator comprises an accumulator filled with compressed gas, a cylinder to which compressed gas is supplied from the accumulator, and a piston slidably provided in the cylinder in the axial direction, and that when compressed gas is supplied to the cylinder, the piston slides axially within the cylinder, causing the rod of the piston to protrude outward from the cylinder and push out and supply the first liquid and the second liquid in the container to the mixer.

[0010] Furthermore, in the spray painting apparatus with the above configuration, it is preferable that a camera is further mounted on the unmanned aerial vehicle.

[0011] Furthermore, in the spray painting apparatus with the above configuration, it is preferable that the mixer is a static mixer. [Effects of the Invention]

[0012] According to the spray coating apparatus of the present invention, spray coating of polyurethane resin or polyurea resin, which uses raw materials with a melting point of room temperature or higher, onto the surface of structures can be performed safely and reliably with a short preparation period and over a wide work area. [Brief explanation of the drawing]

[0013] [Figure 1] This is a side view showing one embodiment of a spray painting apparatus according to the present invention. [Figure 2] Figure 1 is a top view of the spray painting apparatus. [Figure 3] Figure 1 is a schematic diagram of the actuator, container, static mixer, nozzle, and cover of the spray painting apparatus. [Figure 4] This is an example block diagram of a spray painting apparatus according to the present invention. [Figure 5] This flowchart shows an example of control for a spray painting apparatus according to the present invention. [Modes for carrying out the invention]

[0014] The following describes in more detail, with reference to the figures, examples of embodiments relating to the spray painting apparatus of the present invention, but the present invention is not limited in any way to these embodiments.

[0015] Figures 1 and 2 show a side view and a top view illustrating one embodiment of the spray painting apparatus according to the present invention. The spray painting apparatus D shown in these figures comprises an unmanned aerial vehicle 1, two containers 2a and 2b (shown in Figure 3) covered with a heat-insulating member 3 mounted on the unmanned aerial vehicle 1, a static mixer (mixer) 4 for mixing the first liquid L1 and the second liquid L2 (shown in Figure 3) stored in the containers 2a and 2b respectively, an air-operated actuator 5 for pushing and supplying 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. The individual components of the spray painting apparatus D will be described below.

[0016] (Unmanned aerial vehicle) One of the major features of the present invention is the use of the unmanned aircraft 1 as a moving means for spray painting the repair part of the structure. This eliminates the need for preparatory work such as scaffolding assembly and installation of suspended gondolas, and can significantly shorten the working time compared to the conventional method. The unmanned aircraft 1 that can be used in the present invention is not particularly limited as long as it can carry the containers 2a and 2b (shown in FIG. 3) and the actuator 5 described later, and commercially available ones can be used. The unmanned aircraft 1 shown in FIG. 1 includes a main body 10, four rod-shaped support parts 12a to 12d extending outward from the outer peripheral part of the main body 10 at substantially equal angular intervals in a plan view, and four rotary motors 13a to 13d (hereinafter, may be collectively referred to as "rotary motor 13") provided at the tip of each of the four support parts 12a to 12d such that the rotation axis is in the vertical direction, and four rotary wings 14a to 14d (hereinafter, may be collectively referred to as "rotary wing 14") attached to the rotation axis of each of the four rotary motors 13, a control part 15 (shown in FIG. 4) for controlling the rotation etc. of the four rotary motors 13, a communication part 16 (shown in FIG. 4), and a power source 17 (shown in FIG. 4). Note that the main body 10 houses the control part 15, the communication part 16, and the power source 17. In addition, in the present embodiment, the unmanned aircraft 1 is a so-called quadcopter, but it is not limited thereto, and it may be a helicopter or another multicopter having one, three, six, or eight rotary wings 14. When the necessary power for the rotary wing power of the unmanned aircraft cannot be sufficiently filled with a storage battery, the unmanned aircraft can also suspend a power cable and receive power supply from the ground. When the power of the rotary wing is obtained from an engine, a generator may be mounted on the unmanned aircraft and power may be supplied from the generator.

[0017] The buoyancy of the unmanned aircraft 1 is generated by the rotation of the rotary wings 14. The rotation speed of each rotary wing 14 is individually controlled by each rotary motor 13 according to a control signal from the control part 15. Thereby, operations such as the forward, backward, left, and right movements, up and down movements, turning movements, and hovering movements of the unmanned aircraft 1 become possible.

[0018] The unmanned aircraft 1 flies under the remote instruction operation by the operator. The communication unit 16 receives an instruction signal and the driving of a plurality of rotary motors 13 is controlled by the control unit 15. Alternatively, the unmanned aircraft 1 may grasp its current position based on signals from a GPS (Global Positioning System), and further, signals from a ground station, and fly accordingly. Also, in order to realize stable flight, the unmanned aircraft 1 may be equipped with sensors such as an acceleration sensor, an angular velocity sensor, a barometric pressure sensor, an altitude sensor, a wind direction and wind speed sensor, and a gyro sensor (not shown). Further, in order to improve the stability and accuracy of position control, pitch control of the rotor blades may be provided.

[0019] As shown in FIG. 1, a camera 8 is rotatably provided on the lower surface of the main body 10. Further, four rod-shaped legs 9a to 9d are attached to the main body 10 downward. A pedestal 90 is fixed to the middle part in the vertical direction of the four legs 9a to 9d. A heat-insulating member 3 containing containers 2a and 2b described later and an actuator 5 are attached to the upper surface of the pedestal 90.

[0020] The camera 8 controls the shooting direction based on a command from the control unit 15, and shoots the state of the structure surface before and / or after spray painting. The spray painting conditions can also be optimized from the state of the structure surface before and / or after spray painting photographed by the camera 8.

[0021] (Container, heat-insulating member) As shown in Figure 3, two containers 2a and 2b mounted on the unmanned aerial vehicle 1 are filled with a polyisocyanate compound as the first liquid L1 in container 2a and a polyol compound or polyamine compound as the second liquid L2 in container 2b. The two containers 2a and 2b are identical cylindrical in shape, and are partially joined together when placed side by side, and are handled 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 made movable in the axial direction while maintaining liquid-tightness. As will be described later, when the rods 54a and 54b of the actuator 5 protrude, the rear walls 21a and 21b of the containers 2a and 2b move toward the axial end, and the first liquid L1 and the second liquid L2 are extruded and supplied from the containers 2a and 2b to the static mixer 4. Containers 2a and 2b are interchangeable, and when the first liquid L1 and second liquid L2 in containers 2a and 2b are used up, they are replaced with new ones. Note that the two containers 2a and 2b do not need to be joined together and may be separate.

[0022] Containers 2a and 2b, filled with the first liquid L1 and the second liquid L2, are heated by a heater (not shown) on the ground before being mounted on the unmanned aerial vehicle 1. Once a set temperature (e.g., 75°C) is reached, the temperature is maintained, and the containers are mounted on the unmanned aerial vehicle 1 immediately before flight. Since the internal temperature of containers 2a and 2b is affected by the ambient temperature, the outer periphery of containers 2a and 2b is covered with an insulating member 3. Containers 2a and 2b may be mounted on the unmanned aerial vehicle 1 while covered with the insulating member 3, or the insulating member 3 may be provided at the mounting points for containers 2a and 2b on the unmanned aerial vehicle 1. Considering the working time, heating elements such as heaters H (shown in Figure 4) may be attached around containers 2a and 2b in addition to the insulating member 3.

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

[0024] Polyisocyanate compounds are those having two or more isocyanate groups in one molecule. For example, low molecular weight isocyanate compounds such as diphenylmethane-4,4'-diisocyanate (MDI), carbodiimide-modified diphenylmethane diisocyanate (liquid MDI), polymethylene polyphenyl isocyanate (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) can be used.

[0025] Polyol compounds have two or more alcoholic hydroxyl groups in one molecule, and examples of such compounds include polyether polyols, polyester polyols, and polytetramethylene glycols.

[0026] Polyamine compounds are those that have an amino group, and examples of such compounds include aliphatic polyamines like triethylenetetramine, aromatic polyamines like metaphenylenediamine, and alicyclic polyamines like 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, actions such as splitting and merging, local shearing, stretching and folding are at work, and the first liquid L1 and the second liquid L2 are mixed. Note that the mixer used in the present invention is not limited to the static mixer 4, and conventionally known mixers can be used, but the use of the static mixer 4 is preferable because of its simple structure and the fact that it does not require power. It is preferable that the static mixer 4 be replaceable, and it is preferable to replace it with a new one after each spray painting operation is completed. That is, it is preferable to replace the static mixer 4 at the same time as replacing the containers 2a and 2b.

[0028] (nozzle) Nozzle 6 sprays the mixed liquid prepared in the static mixer 4 onto the surface of the structure. Specifically, Nozzle 6 mixes the mixed liquid discharged from the static mixer 4 with air supplied from the accumulator 51 and sprays the mixture. In this embodiment, the spray shape of the mixed liquid is conical, but it is not limited to this and may be a square pyramidal shape, spiral shape, linear shape, etc. Nozzle 6 is detachably attached to the axial end of the static mixer 4. As mentioned above, the static mixer 4 is replaced along with the used containers 2a and 2b, and it is preferable to replace the nozzle 6 in the same manner.

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

[0030] The air pressure filled into the accumulator 51 is determined appropriately based on factors such as the spraying time of the mixed liquid sprayed from the nozzle 6, but 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 factors such as the spraying speed and spray volume, but is usually in the range of 0.1 MPa to 1 MPa.

[0031] When air adjusted to a predetermined pressure by the pressure reducer 56 is supplied from the 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, and moving the rear walls 21a and 21b of the containers 2a and 2b axially forward. As a result, the first liquid L1 and the second liquid L2 in the containers 2a and 2b are pushed out and supplied to the static mixer 4.

[0032] (Cover component) The cover member 7 is intended to prevent the mixed liquid ejected from the nozzle 6 from being disturbed by the airflow from the rotor blades 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 can be appropriately determined according to the ejection shape of the mixed liquid. For example, if the ejection 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 be in contact with the surface of a structure. That is, the cover member 7 may be designed to cover the entire flight path from where the mixed liquid is ejected from the nozzle 6 to the surface of a structure. A flexible material is preferred for the cover member 7.

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

[0034] (Spray painting operation) Figure 5 shows a flowchart illustrating an example of the control of the spray painting apparatus D according to the present invention. The unmanned aerial vehicle 1 flies from a ground base to the repair area on the surface of a structure that requires spray painting, based on remote instructions from the pilot (step S101). Specifically, the pilot inspects the surface of the structure for peeling paint, rust on metal parts, cracks or peeling on the concrete surface, etc., while viewing images transmitted from the camera 8 mounted on the unmanned aerial vehicle 1. Alternatively, if the repair area has been identified and its location information has been entered in a prior inspection, 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 repair area on the surface of the structure, the unmanned aerial vehicle 1 performs a hovering maneuver so that the mixed liquid from the nozzle 6 is sprayed onto the repair area (step S102). Then, the on-off valve 55 is opened and the air supplied from the accumulator 51 is reduced to a predetermined pressure by the pressure reducer 56. The reduced pressure air is then supplied to the cylinder 52 and nozzle 6 of the actuator 5. When air is supplied to the cylinder 52, the piston 53 inside the cylinder 52 moves forward, and the two rods 54a and 54b connected to the piston 53 also move forward. The two rods 54a and 54b then move the rear walls 21a and 21b of the two containers 2a and 2b forward, pushing the first liquid L1 and the second liquid L2 inside the two containers 2a and 2b into the static mixer 4.

[0036] The first liquid L1 and the second liquid L2 are mixed as they pass through the static mixer 4 and supplied to the nozzle 6. The mixed liquid is then sprayed outward from the tip of the nozzle 6 together with air supplied from the accumulator 51 (step S103).

[0037] While the mixed liquid is being sprayed from the nozzle 6, the unmanned aerial vehicle 1 is controlled automatically or remotely so that the sprayed coating film on the repair area reaches the desired thickness. The thickness of the sprayed coating film on the repair area is determined by the amount of mixed liquid sprayed (V(mm)). 3 / s) and spraying area A (mm 2 It is calculated from the quotient V / A(mm) of the mixed liquid spray coating amount V(mm)3 The rate ( / 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 (mm²) of the mixed liquid. 2 The speed ( / s) is determined by the spray shape from the nozzle (including the spread angle), the distance between the nozzle and the repair area, and the speed of the unmanned aerial vehicle 1. Therefore, the unmanned aerial vehicle 1 is controlled to fly at a predetermined speed at a predetermined distance from the repair area so that the sprayed paint film on the repair area reaches the desired 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 painting of the mixed liquid to the repair area is completed ("Y" in step S104), the spray painting 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. After that, it flies back to the repair area and resumes spray painting (steps S101-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), then it is determined by the camera footage whether the spray painting of the repair area has been completed (step S105). If the spray painting of the mixed liquid to the repair area has not been completed ("N" in step S105), the spraying of the mixed liquid continues until the spray painting of the repair area is completed.

[0040] In this embodiment, even if the first liquid L1 and second liquid L2 remain in the container, the aircraft will return to the ground base after spray painting the replenished section, replace the container with a new one, and then fly to the next repair section. This is because the first liquid L1 and second liquid L2 react and solidify immediately upon mixing, causing the container's supply port, static mixer, and nozzle to become blocked during transit to the next repair section.

[0041] Furthermore, without departing from the spirit of the present invention, the components in the embodiments described above can be replaced with well-known components as appropriate, and the modifications described above can be combined as appropriate. [Industrial applicability]

[0042] The spray painting apparatus according to the present invention allows for safe and reliable spray painting of structural surfaces with a short preparation period. [Explanation of Symbols]

[0043] 1 unmanned aerial vehicle 2a,2b container 3. Insulation material 4. Static mixer (mixer) 5 Actuators 6 nozzles 7 Cover 8 cameras 51 Accumulator 52 cylinders 53 Pistons 54a, 54b rods D. Spray painting equipment H heater L1 1st liquid L2 2nd liquid

Claims

1. An apparatus for spray-painting polyurethane resin or polyurea resin onto the surface of a structure using an unmanned aerial vehicle, Unmanned aerial vehicles and Two or more replaceable containers, each storing a first liquid consisting of a polyisocyanate compound and a second liquid consisting of a polyol compound or a polyamine compound, are mounted on the aforementioned unmanned aerial vehicle. A heat-insulating member for keeping the aforementioned container warm, An actuator supplies the first liquid and the second liquid stored in the container to a mixer, A nozzle for spraying the mixed liquid, which has been mixed in the aforementioned mixer, onto the surface of the structure, A spray painting apparatus characterized by being equipped with [a specific feature].

2. The actuator, An accumulator filled with compressed gas, A cylinder supplied with compressed gas from the aforementioned accumulator, The cylinder has a piston that is slidably mounted in the axial direction, The spray painting apparatus according to claim 1, wherein compressed gas is supplied to the cylinder, causing the piston to slide axially 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 in the container to the mixer.

3. The spray painting apparatus according to claim 1 or 2, wherein the mixer is a static mixer.

4. The spray painting apparatus according to claim 1 or 2, further comprising a camera.

5. The spray coating apparatus according to claim 1 or 2, further comprising a cover member that covers the outer circumference of the mixed liquid sprayed from the nozzle.

Images