Coating device, and coating system

Abstract

To suppress lowering of washability of a head.SOLUTION: A coating device includes a first head and a second head which each include at least one nozzle, and discharge liquid from the nozzles and perform coating, and determines the order of coating by the first head and coating by the second head, on the basis of at least one of liquid discharge time of each of the first head and the second head, the number of nozzles and stand-by time of the other head when the one head discharges the liquid.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a painting device and a painting system. [Background technology]

[0002] 2. Description of the Related Art There is known a coating device that performs coating by ejecting a liquid from a head onto an object to be coated.

[0003] For example, Patent Document 1 discloses a configuration having a plurality of heads that each eject liquid in a different direction, and using different ejecting heads depending on the shape of the target object. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device of Patent Document 1, while one head is discharging liquid onto an object, the other head is not discharging liquid. Therefore, when one head starts painting after the other head has finished painting, the nozzle surface of the one head may dry out until the other head finishes painting, which may reduce the cleanability of the head.

[0005] An object of the present invention is to prevent a decrease in the cleaning performance of the head. [Means for solving the problem]

[0006] A coating device according to one embodiment of the present invention has a first head and a second head, each of which contains at least one nozzle and which paints by ejecting liquid from the nozzle, and determines the order of painting by the first head and painting by the second head based on at least one of the liquid ejection time of each of the first head and the second head, the number of nozzles, and the waiting time of one head when the other head is ejecting. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress a decrease in cleaning performance. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing the overall configuration of a coating device according to an embodiment of the present invention; [Figure 2] 3 is a diagram showing a more specific configuration of a liquid supply unit provided in the coating apparatus according to the embodiment of the present invention. FIG. [Figure 3] 1 is a cross-sectional view including a plurality of nozzles of a head provided in a coating device according to an embodiment of the present invention. [Figure 4A] 1 is a block diagram showing a hardware configuration of a coating device according to an embodiment of the present invention. [Figure 4B] 2 is a block diagram showing the functional configuration of a controller provided in the coating device according to the embodiment of the present invention. FIG. [Figure 5] 1 is a diagram showing a first head and a second head provided in a coating device according to a first embodiment of the present invention; [Figure 6] 1 is a diagram showing an example of the configuration of an object to be painted by a painting device according to a first embodiment of the present invention; [Figure 7] 4A and 4B are diagrams showing the states of the first head and the second head during a maintenance and recovery operation in the coating device according to the first embodiment of the present invention. [Figure 8] 4A and 4B are diagrams illustrating a state of a maintenance and recovery unit during a maintenance and recovery operation in the coating device according to the first embodiment of the present invention. [Figure 9A] 2 is a block diagram showing the functional configuration of a controller provided in the coating device according to the first embodiment of the present invention. FIG. [Figure 9B] 4 is a flowchart showing a painting route plan creation operation performed by a painting route planning unit included in the painting apparatus according to the first embodiment of the present invention. [Figure 9C] 4 is a flowchart showing a painting sequence determination operation performed by a painting sequence determination unit included in the painting device according to the first embodiment of the present invention. [Figure 10] 4 is a flowchart showing a first example of a painting and maintenance recovery operation by the painting device according to the first embodiment of the present invention. [Figure 11] FIG. 10 is a diagram showing a first example of the relationship between the order of painting by the first head and the second head in the painting device according to the first embodiment of the present invention and the dryness of the liquid adhering to the nozzle surface of each head. [Figure 12] 10 is a flowchart showing a second example of the painting and maintenance recovery operation by the painting device according to the first embodiment of the present invention. [Figure 13] A figure showing a second example of the relationship between the order of painting by the first head and the second head in the painting device according to the first embodiment of the present invention and the dryness of the liquid adhering to the nozzle surface of each head. [Figure 14] 10 is a flowchart showing a third example of the painting and maintenance recovery operation by the painting device according to the first embodiment of the present invention. [Figure 15A] FIG. 1 is a first diagram showing priority parameters used by a coating device according to a first embodiment of the present invention. [Figure 15B] FIG. 2 is a second diagram showing priority parameters used by the coating device according to the first embodiment of the present invention. [Figure 15C] FIG. 3 is a third diagram showing priority parameters used by the coating device according to the first embodiment of the present invention. [Figure 15D] FIG. 4 is a fourth diagram showing priority parameters used by the painting device according to the first embodiment of the present invention. [Figure 16] FIG. 10 is a diagram showing a first head and a second head provided in a coating apparatus according to a second embodiment of the present invention. [Figure 17A] FIG. 10 is a first diagram showing a coating operation by a first head and a second head provided in a coating device according to a second embodiment of the present invention. [Figure 17B] FIG. 2 is a second diagram showing the coating operation by the first head and the second head provided in the coating device according to the second embodiment of the present invention. [Figure 17C] FIG. 3 is a third diagram showing the coating operation by the first head and the second head provided in the coating device according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A coating device and a coating system according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments are merely examples of a coating device and a coating system for realizing the technical concept of the embodiment of the present invention, and are not intended to be limiting.

[0010] Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of components described in the embodiments of the present invention are not intended to limit the scope of the embodiments of the present invention, but are merely illustrative examples. The sizes, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. In the following description, the same names and symbols indicate the same or similar components, and detailed descriptions will be omitted as appropriate.

[0011] [Embodiment] <Configuration of the coating device according to the embodiment of the present invention> (Overall composition) First, the overall configuration of a coating apparatus according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the overall configuration of a coating apparatus 100 according to an embodiment of the present invention. The coating apparatus 100 applies a liquid to the body of an automobile, which is an object 200, to paint the body. Note that the object 200 is not limited to an automobile body, and may be an aircraft body, a ship hull, or any other three-dimensional structure.

[0012] The painting apparatus 100 includes four painting robots 2. Each painting robot 2 includes a base 10 installed on a floor or the like, a first arm 11 attached to the base 10, a second arm 12 connected to the first arm 11, and a head unit 13 attached to the tip of the second arm 12. The first arm 11 and the second arm 12 of the painting robot 2 are robot arms connected via a joint so as to be rotatable and swingable. The first arm 11 and the second arm 12 of the painting robot 2 function as a movement mechanism that moves the head unit 13 to a desired position by being driven to rotate or swing. Note that the movement mechanism that moves the head unit 13 may be a robot arm, a linear actuator that linearly moves the head unit 13 in one direction, two directions perpendicular to each other, or three directions.

[0013] Specifically, the first arm 11 is rotatable in the direction of arrow A in Fig. 1 relative to the base unit 10 and swingable in the direction of arrow B. The second arm 12 is rotatable in the direction of arrow C in Fig. 1 relative to the tip of the first arm 11 and swingable in the direction of arrow D. The head unit 13 is attached to the tip of the second arm 12 and is rotatable in the direction of arrow E in Fig. 1 relative to the tip of the second arm 12 and swingable in the direction of arrow F. The number of painting robots 2 is not limited to four, and may be one, two, three, five or more.

[0014] The head unit 13 has a head 1 that ejects liquid and a position detection unit 3 that detects the position of the object 200. The head 1 also has multiple nozzles that eject the liquid. The position detection unit 3 is attached to the tip of the second arm 12 integrally with the head 1. The position detection unit 3 includes, for example, a stereo camera that detects three-dimensional position information of three or more feature points on the object 200. The stereo camera has multiple cameras. The position detection unit 3 acquires a range image of the object 200 by triangulation based on the parallax between images captured by the multiple cameras.

[0015] Moreover, the coating device 100 according to the embodiment of the present invention includes a liquid supply unit 4, a maintenance and recovery unit 40, and a control unit 5 in addition to the coating robot 2.

[0016] The liquid supply unit 4 has a liquid storage unit 6 and an air supply unit 7. The liquid storage unit 6 is a tank that stores a liquid 8, such as paint, inside. The air supply unit 7 is a compressor or the like that supplies air into the liquid storage unit 6. When air is supplied from the air supply unit 7 to the liquid storage unit 6, the liquid storage unit 6 is pressurized, and the liquid 8 in the liquid storage unit 6 is supplied to the head 1 and ejected from the nozzle of the head 1 in the form of droplets. Note that the head 1 can also eject the liquid in a filament shape in addition to droplets. While FIG. 1 only shows a path for supplying the liquid 8 from the liquid storage unit 6 to one head 1, the liquid 8 is supplied from the liquid storage unit 6 to all heads 1 in the same way. Alternatively, multiple liquid storage units 6 that store different colors or types of liquid may be provided so that the color or type of liquid can be switched and supplied to each head 1.

[0017] The maintenance and recovery unit 40 has capping means, cleaning means, wiper blades as wiping members, and the like to maintain and recover the functions of the head 1. A maintenance and recovery unit 40 is provided for each painting robot 2. If the next painting will not be performed for a while after painting, or if the painting liquid is switched to a different color or type, the maintenance and recovery operation is performed by the maintenance and recovery unit 40 after the previous painting is completed. Specifically, the nozzle surface of the head 1 is capped, and any residual liquid adhering to the head 1 is washed away with cleaning liquid. This prevents nozzle clogging due to drying of the residual liquid, and also prevents residual liquid from adhering to the object when the painting liquid is switched.

[0018] The control unit 5 controls the operation of each painting robot 2 and the discharge operation of each head 1 based on the shape data and painting data of the object 200 input in advance, as well as the position information of the object 200 detected by the position detection unit 3. As a result, the head unit 13 moves along the shape of the object 200, and the head 1 applies the painting liquid to the surface of the object 200. The control unit 5 also controls the operation of the maintenance and recovery unit 40. Note that while FIG. 1 only shows signal lines from the control unit 5 to one painting robot 2, one head 1, and one maintenance and recovery unit 40, and a signal line from one position detection unit 3 to the control unit 5, the control unit 5 controls the operation of all painting robots 2, all heads 1, and all maintenance and recovery units 40, and receives detection signals from all position detection units 3. The painting data may include, for example, image data of the painted state, painting information (color information) corresponding to the shape data, etc.

[0019] (Liquid supply section 4) FIG. 2 is a diagram showing a more specific configuration of the liquid supply unit 4 provided in the coating apparatus 100 according to the embodiment of the present invention.

[0020] The liquid supply unit 4 has a liquid storage unit 6, an air supply unit 7, and multiple air regulators 9. The air regulator 9 is provided in an air flow path 111 that connects the air supply unit 7 and the multiple liquid storage units 6. The air regulator 9 adjusts the pressure of the air sent from the air supply unit 7 to each liquid storage unit 6. The multiple liquid storage units 6 are individually connected to each head 1 provided on each painting robot 2 via an air flow path 112. Therefore, when the inside of each liquid storage unit 6 is pressurized, liquid 8 is supplied from each liquid storage unit 6 to each head 1. Note that the liquid storage unit 6 does not have to be provided for each head 1, and may be a single liquid storage unit provided commonly to all heads 1.

[0021] (Head 1) FIG. 3 is a cross-sectional view including a plurality of nozzles 24 of the head 1 provided in the coating device 100 according to the embodiment of the present invention.

[0022] A plurality of discharge modules 23 are arranged in one or more rows within the housing 20. Each discharge module 23 has a nozzle plate 25, a nozzle valve 26, a piezoelectric element 27, and a liquid flow path 28. The nozzle plate 25 is provided with a nozzle 24 for discharging liquid for each discharge module 23. The nozzle 24 is configured to be openable and closable by the nozzle valve 26. The piezoelectric element 27 is a driving means that expands and contracts when a voltage is applied, and drives the nozzle valve 26 to open and close. The liquid flow paths 28 communicate with each other between the discharge modules 23, forming a common flow path. The liquid flow path 28 also communicates with the supply port 21 and the recovery port 22.

[0023] When liquid is supplied from supply port 21 into housing 20 while the valve of recovery port 22 is closed, the liquid flows into liquid flow path 28 and becomes pressurized. At this time, if no voltage is applied to piezoelectric element 27, nozzle 24 is closed by nozzle valve 26, and therefore liquid is not ejected from nozzle 24. Note that even when nozzle 24 is closed, liquid can flow through liquid flow path 28. On the other hand, when voltage is applied to piezoelectric element 27, nozzle valve 26 is driven and nozzle 24 is opened, causing liquid to be ejected from nozzle 24. Furthermore, liquid that is not ejected from nozzle 24 is discharged to the outside via recovery port 22.

[0024] (Hardware configuration) FIG. 4A is a block diagram showing an example of the hardware configuration of the coating device 100 according to the embodiment of the present invention.

[0025] 4A, the painting apparatus 100 includes, in addition to multiple painting robots 2, an input device 700A, a computer 300, a controller 400, a head control device 500, and a robot control device 600. Note that only two painting robots 2 are shown here, and the remaining painting robots 2 are omitted.

[0026] Each painting robot 2 has an encoder sensor 16 and a robot driver 17. The encoder sensor 16 is an optical sensor or the like that optically detects slits in encoders provided at the connection between the base 10 and the first arm 11 of the painting robot 2, the connection between the first arm 11 and the second arm 12, and the connection between the second arm 12 and the head unit 13. Detection by the encoder sensor 16 makes it possible to grasp the amount of rotation and swing of each of the first arm 11, the second arm 12, and the head unit 13, thereby obtaining three-dimensional position information of the head unit 13. The robot driver 17 is a driver that performs the rotational and swinging movements of the first arm 11, the second arm 12, and the head unit 13.

[0027] The input device 700A is a device into which information such as shape data of the object 200, image data of the painting, coordinate data, painting mode, painting range (painting start position, painting end position), painting instructions, etc. is input. The input device 700A has a keyboard, mouse, touch panel, etc. for a user to perform input operations. The various information input by the input device 700A is sent to the computer 300.

[0028] The computer 300 includes a RIP (Raster Image Processor) unit 301 that performs image processing on image data received from the input device 700A, and a rendering unit 302 that breaks down the image data into paint data for each scan of the head unit 13. The computer 300 also receives shape data of the object 200 from the input device 700A and acquires actual position information of the object 200 detected by the position detection unit 3. The computer 300 then generates a painting route for the painting robot 2 based on the shape data and actual position information of the object 200. The computer 300 also calculates the incident angle α of droplets relative to the object 200 along the generated painting route. The incident angle α is calculated using one or more of the shape data of the object 200 received from the input device 700A, the position information of the object 200 detected by the position detection unit 3, and the three-dimensional position information of the head unit 13 detected by the encoder sensor 16.

[0029] 1 , which controls the operation of each painting robot 2 and the discharge operation of each head 1. In this case, one head control device 500 and one robot control device 600 are provided, but the head control device 500 and the robot control device 600 may be provided individually for each painting robot 2.

[0030] The controller 400 receives painting data and command signals from the computer 300 and controls the overall operation of the painting device 100 .

[0031] The controller 400 includes a CPU (Central Processing Unit) 401, a ROM (Read Only Memory) 402, a RAM (Random Access Memory) 403, an HDD / SSD (Hard Disk Drive / Solid State Drive) 404, and an I / F 405. These are connected via a system bus S so that they can communicate with each other.

[0032] The CPU 401 executes control processing including various types of arithmetic processing. The ROM 402 stores programs used to drive the CPU 401, such as an IPL (Initial Program Loader). The RAM 403 is used as a work area for the CPU 401. The HDD / SSD 404 stores various types of information such as programs, captured images acquired by the stereo camera, and detection information from various sensors such as the encoder sensor 16. The I / F 405 is an interface for connecting the controller 400 to various external devices. Here, the external devices include the head control device 500 and the robot control device 600. Note that at least some of the functions implemented by the CPU 401 may be implemented by electric or electronic circuits.

[0033] The head control device 500 receives a control signal and a discharge cycle signal from the controller 400, and controls the discharge amount and discharge timing of the head 1 based on the received control signal and discharge cycle signal. At this time, the discharge amount and discharge timing of the head 1 are controlled based on the incident angle α, so that the amount of discharged droplets and the landing interval Px in the movement direction X are controlled to the amount of droplets and the landing interval according to the incident angle α.

[0034] The robot control device 600 receives a control signal from the controller 400 and controls the driving of the robot driving unit 17 based on the received synchronization control signal. At this time, by controlling the robot driving unit 17 based on the incident angle α, the tilt β of the nozzle row of the head 1 is controlled, and the landing interval Py in the direction perpendicular to the movement Y is controlled to an interval corresponding to the incident angle α.

[0035] (Functional configuration of the controller in the embodiment of the present invention) 4B is a block diagram showing an example of the functional configuration of the controller 400 included in the coating apparatus 100 according to the embodiment of the present invention. The description will also refer to FIG. 4A as needed.

[0036] The controller 400 has a system control unit 411, a nozzle valve drive control unit 412, a discharge period signal generation unit 413, a memory control unit 414, a data storage unit 415, a robot control signal generation unit 416, and a maintenance recovery control unit 418.

[0037] The functions of the system control unit 411, nozzle valve drive control unit 412, discharge period signal generation unit 413, memory control unit 414, robot control signal generation unit 416, and maintenance / recovery control unit 418 are realized by the CPU 401 executing processes defined in programs stored in a nonvolatile memory such as the ROM 402. The function of the data storage unit 415 is realized by a nonvolatile memory such as the HDD / SSD 404. The system control unit 411 receives painting data and command signals from the computer 300 and controls the overall operation of the painting apparatus 100. The system control unit 411 may also include the functions of the RIP unit 301 and rendering unit 302 of the computer 300.

[0038] The nozzle valve drive control unit 412 generates a control signal for controlling the opening and closing of the nozzle valve 26 based on the painting data and incident angle α received from the computer 300. The discharge period signal generation unit 413 generates a discharge period signal for the head 1 based on the output signal from the encoder sensor 16 and the painting data and incident angle α received from the computer 300. The memory control unit 414 controls the data storage unit 415. The data storage unit 415 stores the painting data, painting area data, etc. received from the computer 300. The robot control signal generation unit 416 generates a synchronization control signal for coordinating the driving of each painting robot 2 with the droplet discharge operation based on the painting data and painting route information from the computer 300. The robot control signal generation unit 416 also generates a control signal for determining the inclination β of the nozzle row of the head 1 based on the incident angle α calculated by the computer 300. The maintenance and recovery control unit 418 controls the operation of the maintenance and recovery unit 40.

[0039] [First embodiment] <Configuration of the coating device according to the first embodiment of the present invention> (First head 1A and second head 1B) Fig. 5 is a diagram showing an example of the configuration of a first head 1A and a second head 1B provided in a coating apparatus 100 according to a first embodiment of the present invention. Fig. 6 is a diagram showing an example of the configuration of an object 200 to be coated by the coating apparatus 100 according to a first embodiment of the present invention. In the example shown in Fig. 5, in order to indicate that each of the first head 1A and the second head 1B includes the head 1 shown in Fig. 3, the reference numeral of the first head 1A is written in parentheses next to the reference numeral of the head 1, and the reference numeral of the second head 1B is written in parentheses next to the reference numeral of the head 1. Hereinafter, reference numerals may be written in parentheses for the same purpose.

[0040] A coating apparatus 100 according to a first embodiment of the present invention includes a first head 1A and a second head 1B. Each of the first head 1A and the second head 1B includes at least one nozzle 24, and discharges a liquid from the nozzle 24 to perform coating.

[0041] For example, in a coating device that uses two heads to spray liquid, one head may not spray liquid while the other head is spraying liquid onto a target object. In a coating device that does not clean the two heads until each head has finished spraying, the liquid may dry out in the head that is not spraying liquid, increasing the viscosity of the liquid and solidifying components contained in the liquid, thereby reducing the cleanability of the head. For example, when the liquid is not drying out, wiping the vicinity of the nozzle with a wiping member can easily remove the liquid adhering to the nozzle, allowing the head to be cleaned effectively. In contrast, when the liquid is drying out, components contained in the liquid may adhere to the nozzle, making it impossible to remove the liquid adhering to the vicinity of the nozzle even by wiping the vicinity of the nozzle, or the time required for removal may increase, reducing the cleanability of the head.

[0042] If the two heads are not cleaned until each has finished discharging, the head that comes first in the coating order will have to wait longer before being cleaned, which will cause the liquid to dry out and make the head less cleanable. Furthermore, if the head with the longer discharging time discharges later, the head that discharged first with the shorter discharging time will not be cleaned until the head with the longer discharging time has finished discharging, which will cause the liquid to dry out and make the head less cleanable. Furthermore, the head with the greater number of nozzles has a relatively higher probability of liquid components adhering to the nozzles due to drying than the head with the fewer nozzles (a greater number of nozzles means a greater amount of liquid remains near the nozzles, which increases the likelihood of the liquid adhering to the nozzles), making the head less cleanable.

[0043] The coating apparatus 100 according to this embodiment determines the order of coating by the first head 1A and the second head 1B based on at least one of the liquid discharge time, the number of nozzles 24, and the standby time of one head when the other head is discharging. For example, if the discharge time of the first head 1A is longer than the discharge time of the second head 1B, the coating apparatus 100 determines the order of coating so that the first head 1A paints before the second head 1B. This results in the first head 1A having a standby time before cleaning being approximately the same as the discharge time of the second head 1B, thereby shortening the standby time before cleaning compared to when the second head 1B paints first. By shortening the standby time before cleaning, the liquid is prevented from drying out, and the head's cleanability is prevented from deteriorating. Furthermore, in the coating apparatus 100 according to this embodiment, when the number of nozzles in the first head 1A is smaller than the number of nozzles in the second head 1B, the coating order is determined so that the first head 1A is coated before the second head 1B. This shortens the waiting time before cleaning the second head 1B, which is likely to have liquid components adhere to its nozzles due to drying. This prevents the liquid from drying out and reduces the deterioration of the head's cleanability. Furthermore, in this embodiment, cleaning is performed at once after all heads have finished discharging. This shortens the head cleaning time compared to coating apparatuses that sequentially clean the two heads after each head has finished discharging. As a result, the productivity of the coating apparatus 100 can be improved.

[0044] There are the following methods for determining the painting order. Here, we will explain the method using two heads (first head 1A and second head 1B). (1) The coating sequence is determined based on the liquid ejection time (including the non-ejection time between the first drop and the next drop) by the first head 1A and the liquid ejection time (including the non-ejection time between the first drop and the next drop) by the second head 1B. In addition to the judgment based on the "discharge time" in (1) above, the order of coating may also be determined based on the "standby time." Specifically, (2) The order of coating may be determined by using the time during which the second head 1B is not ejecting liquid at that time, i.e., the “standby time” of the second head 1B, as the time during which the first head 1A ejects liquid (including the non-ejection time between the first drop and the next drop), or by using the time during which the first head 1A is not ejecting liquid at that time, i.e., the “standby time” of the first head 1A, as the time during which the second head 1B ejects liquid (including the non-ejection time between the first drop and the next drop).

[0045] (Discharge time) The "discharge time" in the first embodiment of the present invention will be described. The "discharge time of one droplet" includes the discharge time of the first droplet from a certain nozzle and the non-discharge time between the next droplet. For example, when 1,000 droplets are continuously discharged, the "discharge time" is 1,000 times the sum of the discharge time of the first droplet and the non-discharge time between the next droplet. Note that even if the liquid is in the form of threads, when coating is performed by continuously discharging the liquid without switching between the first head 1A and the second head 1B, the non-discharge time between the threads is also included in the discharge time.

[0046] Furthermore, the fixed time required for continuous or intermittent ejection of droplets from a head having multiple nozzles is defined as the "liquid ejection time" from that head. In other words, the liquid ejection time from the first head 1A refers to the time including the non-ejection time between one droplet from the nozzle of the first head 1A and the next droplet. Similarly, the liquid ejection time from the second head 1B refers to the time including the non-ejection time between one droplet from the nozzle of the second head 1B and the next droplet.

[0047] At this time, while the first head 1A is painting (discharging liquid), the second head 1B is not painting. Therefore, the "liquid discharge time" of the first head 1A corresponds to the "time during which the second head 1B is not discharging liquid," i.e., the "standby time." Therefore, for example, when determining the order of painting in the first embodiment of the present invention, the "liquid standby time of the second head 1B" may be used instead of the "liquid discharge time of the first head 1A." Note that a comparison between the "discharge time" and the "standby time" may also be performed. For example, the order of painting may be determined based on the "liquid discharge time of the first head 1A" and the "standby time of the first head 1A."

[0048] In addition, in a head having multiple nozzles, if only some of the nozzles are used for painting and the majority of the other nozzles (however, the nozzles have been used to paint at least once) are not used for painting, and if the degree of dryness around the nozzles increases during that time, that time can be considered as ``standby time.''

[0049] Furthermore, an increase in the head switching time increases the total time of the painting process. Therefore, it is better to minimize the number of head switching times during the "total painting time" (= the discharge time of the first head 1A (the standby time of the second head 1B) + the standby time of the first head 1A (the discharge time of the second head 1B) + the switching time of the painting head (when the first head 1A is used as the reference)). Therefore, it is preferable to consider minimizing the number of switching times when determining the painting order. Furthermore, the discharge time is not limited to the future discharge time when planning before the start of painting. For example, when revising the plan after the start of painting, the time required for painting may be included. Note that when revising the plan after the start of painting, the painting order may also be determined taking into account the head usage status up to that point (for example, the start time of painting, the standby time between one discharge to check head operation and the next discharge, etc.).

[0050] (painting time) The "total painting time" in the first embodiment of the present invention will be described. For example, if a first painting area is painted with a first head 1A and a second painting area is painted with a second head 1B, the "total painting time" for the first and second painting areas is the "painting time for the first painting area" + "painting time for the second painting area" + "head switching time." Regarding "painting time," for example, the standby time of the second head 1B while the first head 1A is painting the first painting area corresponds to the "non-painting time of the second head 1B." Similarly, the standby time of the first head 1A while the second head 1B is painting the second painting area corresponds to the "non-painting time of the first head 1A."

[0051] The second head 1B has multiple heads 1 shown in Fig. 3. In the example shown in Fig. 5, the second head 1B has 12 heads 1 arranged in a direction perpendicular to the direction in which the nozzles 24 are arranged. The second head 1B is supported by a second arm 12 of the painting robot 2. The first head 1A is supported by the second head 1B via the support member 30 of the single head 1 shown in Fig. 3.

[0052] The first head 1A includes a first nozzle surface 15A on which nozzles are provided. The second head 1B includes a second nozzle surface 15B on which nozzles are provided. The first head 1A and the second head 1B are arranged such that the first nozzle surface 15A and the second nozzle surface 15B face in different directions when the first head 1A and the second head 1B are attached to the second arm 12. In the example shown in FIG. 5, the first nozzle surface 15A and the second nozzle surface 15B face in directions perpendicular to each other. By arranging the first nozzle surface 15A and the second nozzle surface 15B to face in different directions, when the target object 200 includes multiple surfaces that intersect with each other, the tilt angle of the first head 1A and the second head 1B can be made smaller to paint the multiple surfaces compared to when the first head 1A and the second head 1B face in the same direction. However, the orientations of first nozzle surface 15A and second nozzle surface 15B are not limited to directions perpendicular to each other, and may be in directions that intersect other than the perpendicular directions, such as when they are inclined.

[0053] In the coating apparatus 100, the first head 1A is supported by the support member 30, allowing for satisfactory coating of an object 200 with a complex structure, such as a vehicle body. For example, as shown in FIG. 6, a first region 201 can be coated by the second head 1B, and a second region 202, which is narrower than the first region 201, can be coated by the first head 1A. Because the first head 1A is disposed to protrude from the tip of the second arm 12 via the plate-shaped support member 30, the first head 1A can enter narrow areas, even in the object 200 with a complex structure. At the same time, the first head 1A can approach the object 200 while avoiding interference with the object 200. As a result, even difficult-to-paint portions of the object 200 can be coated satisfactorily.

[0054] In the coating apparatus 100, the orientations of the first nozzle surface 15A and the second nozzle surface 15B intersect. Therefore, in the coating apparatus 100, the maintenance and recovery unit 40 performs an operation of covering the first nozzle surface 15A and the second nozzle surface 15B with cap members at different times while the second arm 12 of the coating robot 2 is stationary.

[0055] (Maintenance and Recovery Department 40) The configuration of the maintenance and recovery unit 40 provided in the coating apparatus 100 according to the first embodiment of the present invention will be described with reference to Figures 7 and 8. Figure 7 is a diagram showing an example of the state of the first head 1A and the second head 1B during the maintenance and recovery operation in the coating apparatus 100 according to the first embodiment of the present invention. Figure 8 is a diagram showing an example of the state of the maintenance and recovery unit 40 during the maintenance and recovery operation in the coating apparatus 100 according to the first embodiment of the present invention.

[0056] The maintenance and recovery unit 40 has cap members 41 that cover the nozzles 24 included in the first head 1A and the second head 1B. The maintenance and recovery unit 40 also has a first maintenance and recovery unit 40A that is used for maintenance and recovery operations of the first head 1A, and a second maintenance and recovery unit 40B that is used for maintenance and recovery operations of the second head 1B, which is larger than the first head 1A. The configuration of the first maintenance and recovery unit 40A and the configuration of the second maintenance and recovery unit 40B may be substantially the same. Therefore, in the description of Figure 8, the first maintenance and recovery unit 40A will be used as a representative.

[0057] The first maintenance and recovery unit 40A shown in FIG. 8 includes a cap member 41, a cleaning unit 42, and a drying unit 43. The cap member 41 includes a cap body 50 formed in a concave shape and a sealing unit 51 provided around the entire edge of the opening 50a of the cap body 50. The sealing unit 51 is made of an elastic material such as rubber. The cleaning unit 42 and the drying unit 43 are arranged within the cap body 50. The cleaning unit 42 includes a cleaning nozzle 52 that ejects cleaning liquid. The drying unit 43 includes a drying nozzle 53 that blows dry air such as warm air. The dry air is not limited to warm air, and may be cold air. A waste liquid flow path 54 is provided at the bottom of the cap body 50 to discharge the cleaning liquid from the cap body 50 to a waste liquid tank.

[0058] When the maintenance and recovery unit 40 is used to maintain and recover the discharge functions of the first head 1A and the second head 1B, the coating apparatus 100 first drives the coating robot 2 to move the second head 1B to a position facing the cap member 41 of the second maintenance and recovery unit 40B. Then, as shown in FIG. 7, the coating apparatus 100 presses the second nozzle surface 15B of the second head 1B against the cap member 41 to bring them into contact. This causes the second nozzle surface 15B of the second head 1B to be covered by the cap member 41 of the second maintenance and recovery unit 40B. Furthermore, the cap member 41 of the second maintenance and recovery unit 40B is pressed against the second head 1B, causing the seal portion 51 (see FIG. 8) of the cap member 41 to come into close contact with the second nozzle surface 15B. This creates a seal between the second nozzle surface 15B and the second cap member 41B. At this time, the first head 1A is positioned facing the cap member 41 of the first maintenance and recovery unit 40A.

[0059] As shown in FIG. 8, the coating apparatus 100 moves the cap member 41 of the first maintenance and recovery unit 40A in the Z direction and presses it into contact with the first nozzle surface 15A of the first head 1A. Furthermore, the coating apparatus 100 presses the cap member 41 of the first maintenance and recovery unit 40A against the first head 1A. This causes the seal portion 51 of the cap member 41 of the first maintenance and recovery unit 40A to come into close contact with the first nozzle surface 15A, sealing the space between the first nozzle surface 15A and the cap member 41 of the first maintenance and recovery unit 40A. In this state, the coating apparatus 100 can perform a maintenance and recovery operation using the maintenance and recovery unit 40, i.e., clean the first nozzle surface 15A and the second nozzle surface 15B using the cleaning unit 42 and drying unit 43.

[0060] (Functional configuration of the controller in the first embodiment of the present invention) The functional configuration of the controller 400 included in the coating apparatus 100 according to the first embodiment of the present invention will be described with reference to Figures 9A, 9B, and 9C. Figure 9A is a block diagram showing an example of the functional configuration of the controller 400 included in the coating apparatus 100 according to the first embodiment of the present invention.

[0061] The controller 400 shown in Fig. 9A differs from the controller 400 shown in Fig. 4A mainly in that it includes a painting route planning unit 419 and a painting sequence determination unit 420. The control unit 5 including the controller 400 shown in Fig. 9A corresponds to the control unit that controls the ejection of liquid by the first head 1A and the second head 1B.

[0062] The functions of the painting route planning unit 419 and the painting sequence determination unit 420 are realized by the CPU 401 executing processes defined in programs stored in a non-volatile memory such as the ROM 402. Note that the functions of the painting route planning unit 419 and the painting sequence determination unit 420 may be realized by an external device other than the controller 400, such as the computer 300, with the functional configuration of the controller 400 being the configuration shown in Fig. 4B, or may be realized by distributed processing between the controller 400 and an external device other than the controller 400, such as the computer 300.

[0063] The painting route planning unit 419 plans a painting route, for example, at the start of painting (step S01). The painting route refers to the path along which the first head 1A and the second head 1B are moved relative to the object 200 in order to paint the entire painting area of ​​the object 200. The painting route planning unit 419 plans a painting route based on the painting area determined by the shape of the painting area on the object 200 and the shapes of the first head 1A and the second head 1B that will paint this painting area or the arrangement of the nozzles 24. The painting route planning unit 419 also plans which of the first area 201 or the second area 202 shown in FIG. 6 should be painted first, and whether the first head 1A or the second head 1B should be used for painting, etc.

[0064] 9B can be omitted by using information on the painting route acquired from the computer 300. Furthermore, the timing for planning the painting route is not limited to the start of painting. It can also be the timing of maintenance and recovery control (capping, etc.), or the timing when one of the heads discharges.

[0065] 9B is a flowchart showing an example of a process for creating a painting route plan by the painting route planning unit 419 included in the painting apparatus 100 according to the first embodiment of the present invention. As an example, the painting route planning unit 419 starts the operation shown in FIG. 9B at the start of painting (when a new painting command is issued after the previous maintenance and recovery operation).

[0066] First, in step S11, the painting route planning unit 419 acquires the shape data of the object to be painted.

[0067] Next, in step S12, the painting route planning unit 419 acquires painting area data.

[0068] Subsequently, in step S13, the painting route planning unit 419 acquires information about the head (head shape data).

[0069] Next, in step S14, the painting route planning unit 419 acquires nozzle arrangement data.

[0070] Next, in step S15, the painting route planning unit 419 creates a painting route plan.

[0071] Next, in step S16, the painting route planning unit 419 acquires or estimates information about the painting time from the planned painting route.

[0072] At the start of painting, if there is no opportunity to change the painting order, the painting route planning unit 419 provides the planned painting route to the head drive program. On the other hand, if the setting (or instruction) is to determine the painting order, the painting order is subsequently determined.

[0073] The order of steps S11 to S14 may be changed as appropriate, and the steps may be executed in parallel.

[0074] The painting order determination unit 420 determines the order of painting by the first head 1A and the second head 1B based on at least one of the liquid ejection time and the number of nozzles 24 of each of the first head 1A and the second head 1B.

[0075] FIG. 9C is a flowchart showing an example of the coating order determination process performed by the coating order determination unit 420 included in the coating apparatus 100 according to the first embodiment of the present invention. Examples of timings for the coating order determination unit 420 to determine the coating order include when the first head 1A and the second head 1B are both clean, i.e., at the start of the coating process, or immediately after the first head 1A and the second head 1B have been cleaned. However, the timing is not limited to "immediately after." It may also be scheduled during cleaning or while operation is stopped after cleaning. The plan may also be revised. For example, the plan may be revised when an event occurs, such as a change in the degree of dryness, when one of the robots is interrupted due to a defect and repair painting is performed, or when repair painting is performed due to the detection of a paint defect.

[0076] First, in step S21, the painting sequence determination unit 420 determines the liquid ejection time for each of the first head 1A and the second head 1B in each painting area based on the size and position of the painting area in the painting route planned by the painting route planning unit 419.

[0077] Next, in step S22, the painting sequence determination unit 420 determines whether painting by the first head 1A and painting by the second head 1B are appropriate based on the liquid discharge time. Specifically, if it is determined that the dryness near the nozzles of the first head 1A and the second head 1B will be below the threshold value after the "painting time" estimated in step S16 has elapsed (after painting is completed) in the planned painting route and in the default painting sequence (e.g., painting by the first head 1A and then the second head 1B) (step S22, YES), the painting sequence determination unit 420 ends the processing without changing the painting sequence. On the other hand, if it is determined in step S22 that the dryness will exceed the threshold value (i.e., the nozzle cleanability will be reduced) (step S22, NO), the painting sequence determination unit 420 will change the painting sequence, etc.

[0078] Next, in step S23, the painting order determination unit 420 determines whether the discharge times of the first head 1A and the second head 1B are the same. If it is determined in step S23 that the discharge times are the same (step S23, YES), the painting order determination unit 420 changes the order of the first head 1A and the second head 1B so that the head with the fewer nozzles is painted first in step S24. The painting order determination unit 420 then terminates the process. On the other hand, if it is determined in step S23 that the discharge times are not the same (step S23, NO), the painting order determination unit 420 changes the order of the first head 1A and the second head 1B so that the head with the longer discharge time is painted first in step S25.

[0079] Next, in step S26, the painting sequence determination unit 420 determines whether the drying near the nozzles of each head is below a threshold, i.e., whether the nozzles are not dry. If it is determined in step S26 that the nozzles are not dry (YES in step S26), the painting sequence determination unit 420 determines the painting sequence at that time and then terminates processing. On the other hand, if it is determined that the nozzles are dry (NO in step S26), the painting sequence determination unit 420 adds 1 to the head switching count in step S27. For example, if the painting sequence is to be performed with the second head 1B first and then the first head 1A, the head switching count is "1." In contrast, the head switching count is increased so that part of the painting process by the second head 1B follows the painting process by the first head 1A. In other words, painting is performed in the order of the second head 1B, the first head 1A, and the second head 1B. In this case, the head switching count is "2." Although increasing the head switching count slightly extends the painting time, the order is determined with a priority given to preventing the nozzles from drying out. The painting sequence determination unit 420 can allocate the head switching timing according to a predetermined condition, for example, by setting ¼ of the discharge time as the latter half. After that, the painting sequence determination unit 420 performs the processing from step S22 onwards again.

[0080] As described above, the coating sequence is determined so that the nozzle dryness at the time of completion of coating is equal to or less than the threshold value, thereby making it possible to prevent a decrease in the cleaning performance of the head.

[0081] Note that the order of S23 to S27 in this flowchart is not limited to the order shown in Fig. 9C. For example, it is also possible to calculate priority parameters from the "number of nozzles" and "discharge time" of each head, and determine the coating order by comparing these parameters.

[0082] <Operation of the coating device according to the first embodiment of the present invention> (First example) A first example of the operation of the coating apparatus according to the first embodiment of the present invention will be described with reference to Figures 10 and 11. Figure 10 is a flowchart showing a first example of the maintenance and recovery operation performed by the coating apparatus 100. Figure 11 is a diagram showing a first example of the relationship between the order of coating by the first head 1A and the second head 1B in the coating apparatus 100 according to the first embodiment of the present invention and the dryness of the liquid adhering to the nozzle surface of each head. Figure 11 shows an example of the change over time in the dryness of the liquid on the first nozzle surface 15A in the upper part, and an example of the change over time in the dryness of the liquid on the second nozzle surface 15B in the lower part.

[0083] The coating apparatus 100 starts the operation of FIG. 10 when, for example, an operation to start the maintenance and recovery operation is received via an operation unit provided in the coating apparatus 100. However, the start condition of the operation of FIG. 10 is not limited to the reception of the start operation and can be set as appropriate. In the operation shown in FIG. 10, the liquid ejection time of the second head 1B is assumed to be longer than the liquid ejection time of the first head 1A. Furthermore, the coating route is assumed to be planned in advance by the coating route planning unit 419, and the coating order is assumed to be determined in advance by the coating order determination unit 420.

[0084] First, in step S31, the painting device 100 drives the second arm 12 using the painting robot 2 in accordance with the painting sequence determined by the painting sequence determination unit 420, and moves the second head 1B to a position facing the first region 201 of the object 200 shown in Figure 6, i.e., the starting position for painting by the second head 1B.

[0085] Next, in step S32, the coating apparatus 100 opens the nozzle valve 26 of the second head 1B to discharge liquid from the second head 1B, thereby coating the first region 201 of the target object 200. The coating apparatus 100 continues coating until the coating time T1 shown in FIG.

[0086] Next, in step S33, when painting by the second head 1B is completed, the painting device 100 causes the painting robot 2 to drive the second arm 12 in accordance with the painting sequence determined by the painting sequence determination unit 420. By driving the second arm 12, the painting device 100 moves the first head 1A to a position facing the second region 202 of the target object 200, i.e., the painting start position by the first head 1A.

[0087] Next, in step S34, the coating apparatus 100 opens the nozzle valve 26 of the first head 1A to discharge the liquid from the first head 1A, thereby coating the second region 202 of the target object 200. The coating apparatus 100 continues coating until the coating time T2 shown in FIG.

[0088] Next, in step S35, when painting by the first head 1A is completed, the painting apparatus 100 causes the painting robot 2 to drive the second arm 12, and the cap member 41 covers the first nozzle surface 15A and the second nozzle surface 15B. This reduces drying of the liquid on each of the first nozzle surface 15A and the second nozzle surface 15B, and suppresses a decrease in the cleanability of each of the first nozzle surface 15A and the second nozzle surface 15B. The painting apparatus 100 performs the operation of step S35 during period T3 shown in FIG.

[0089] Subsequently, in step S36, the coating apparatus 100 performs a maintenance and recovery operation by the maintenance and recovery unit 40 to clean the first nozzle surface 15A and the second nozzle surface 15B using the cleaning unit 42 and the drying unit 43. The coating apparatus 100 performs the operation of step S36 during a period T4 shown in FIG.

[0090] As a result, the painting device 100 can paint the first area 201 and the second area 202 of the object 200.

[0091] In the first example, painting is performed first by the second head 1B, which has a longer painting time T1 (S32), and then painting is performed by the first head 1A for a painting time T2, which is shorter than the painting time T1 (S34). This makes it possible to prevent a decrease in head cleanability due to the progress of drying of the liquid adhering to the second nozzle surface 15B of the second head 1B, which ejected the liquid earlier, while painting is being performed by the first head 1A. Furthermore, since the degree of dryness of the liquid before cleaning is suppressed, the cleaning time can be shortened as a result.

[0092] In the first example, after painting is performed by the first head 1A and the second head 1B, the first nozzle surface 15A and the second nozzle surface 15B are covered by the cap member 41 (S35). This improves productivity compared to a case in which the first nozzle surface 15A is covered with the cap member 41 after painting is performed by the first head 1A, and then the second nozzle surface 15B is covered with the cap member 41 after painting is performed by the second head 1B.

[0093] The heads used in the first example are not limited to the first head 1A and the second head 1B shown in FIG. 5. For example, the number of heads 1 included in the first head 1A may be the same as the number of heads 1 included in the second head 1B, and the number of nozzles 24 included in the first head 1A may be the same as the number of nozzles 24 included in the second head 1B. Furthermore, after performing step S16 in FIG. 10, further coating may be performed. At this time, the same operations as steps S31 to S34 may be performed, or coating may be performed using only one of the first head 1A and the second head 1B.

[0094] (Second example) A second example of the operation of the coating apparatus according to the first embodiment of the present invention will be described with reference to Figures 12 and 13. Figure 12 is a flowchart showing a second example of the maintenance and recovery operation performed by the coating apparatus 100. Figure 13 is a diagram showing a second example of the relationship between the order of coating by the first head 1A and the second head 1B in the coating apparatus 100 according to the first embodiment of the present invention and the dryness of the liquid adhering to the nozzle surface of each head. Figure 13 shows an example of the change over time in the dryness of the liquid on the first nozzle surface 15A in the upper part, and an example of the change over time in the dryness of the liquid on the second nozzle surface 15B in the lower part.

[0095] After discharging, the first nozzle surface 15A and the second nozzle surface 15B dry out, and if discharging is performed again without cleaning the first nozzle surface 15A and the second nozzle surface 15B, discharging failures are likely to occur. Therefore, from the perspective of coating quality, when coating using the first head 1A and the second head 1B, it is desirable to perform coating continuously at one time and avoid intermittent coating operations. However, depending on the requirements of the coating route and quality conditions, the coating apparatus 100 can also perform multiple discontinuous coatings. When performing multiple discontinuous coatings, the coating apparatus 100 determines the order of coating by the first head 1A and the second head 1B based on the respective discharge times of the first head 1A and the second head 1B. For example, the order of coating by the first head 1A and the second head 1B is determined so that the head with the longer discharge time is coated first, and then coating is performed alternately using the first head 1A and the second head 1B. In other words, if the discharge time of the first head 1A is longer than the discharge time of the second head 1B, the first head 1A will paint before the second head 1B, and the second head 1B will paint after the first head 1A has finished painting.The first head 1A will paint again after the second head 1B has painted.These operations reduce the occurrence of discharge defects and improve painting quality, even when performing multiple discontinuous coatings according to the requirements and quality conditions of the painting route.These operations are described in detail below.

[0096] The coating apparatus 100 starts the operation of Fig. 12 when, for example, an operation to start the maintenance and recovery operation is received via an operation unit provided in the coating apparatus 100. In the operation shown in Fig. 12, the time for which the first head 1A ejects liquid is longer than the time for which the second head 1B ejects liquid. The following mainly describes the differences from the operation shown in Fig. 10.

[0097] In step S42, the coating apparatus 100 opens the nozzle valve 26 of the second head 1B to discharge liquid from the second head 1B, thereby coating the first region 201 of the target object 200. The coating apparatus 100 performs coating until the coating time T1-1 shown in FIG. 13 has elapsed.

[0098] Next, in step S45, the painting device 100 drives the second arm 12 using the painting robot 2 to move the second head 1B to a position facing the first area 201 of the object 200 shown in Figure 6, i.e., the starting position for painting by the second head 1B.

[0099] Next, in step S46, the coating apparatus 100 opens the nozzle valve 26 of the second head 1B to discharge liquid from the second head 1B, thereby coating the first region 201 of the target object 200. The coating apparatus 100 performs coating until the coating time T1-2 shown in FIG. 13 has elapsed.

[0100] As described above, the painting device 100 can paint the first area 201 and the second area 202 of the object 200 when performing multiple discontinuous painting operations according to the requirements of the painting route and quality conditions.

[0101] The second example can also achieve the same effects as the first example. The heads used in the second example are not limited to the first head 1A and the second head 1B shown in FIG. 5. For example, the number of heads 1 included in the first head 1A may be the same as the number of heads 1 included in the second head 1B, or the number of nozzles 24 included in the first head 1A may be the same as the number of nozzles 24 included in the second head 1B. Furthermore, after step S48 in FIG. 12 is performed, further coating may be performed. In this case, the same operations as steps S41 to S47 may be performed, or coating may be performed using only one of the first head 1A and the second head 1B.

[0102] (Third example) A third example of the operation of the coating apparatus according to the first embodiment of the present invention will be described with reference to Fig. 14. Fig. 14 is a flowchart showing a third example of the maintenance and recovery operation by the coating apparatus 100 according to the first embodiment of the present invention.

[0103] The greater the number of nozzles 24 used in coating, the greater the likelihood that liquid will adhere to the first nozzle surface 15A and the second nozzle surface 15B due to malfunctions such as non-ejection of liquid from the nozzles 24. If liquid adheres to the first nozzle surface 15A and the second nozzle surface 15B, the adhering liquid is likely to dry out, resulting in a decrease in cleanability. In the third example, by ejecting liquid from the head with the fewest number of nozzles 24 first, it is possible to reduce the adhesion of liquid to the first nozzle surface 15A and the second nozzle surface 15B and prevent a decrease in the cleanability of the first head 1A and the second head 1B.

[0104] The coating apparatus 100 starts the operation of Figure 14 when, for example, an operation to start the maintenance and recovery operation is received via an operation unit provided in the coating apparatus 100. Note that the number of nozzles N1 of the first head 1A is assumed to be smaller than the number of nozzles N2 of the second head 1B. Below, differences from the operation shown in Figure 10 will be mainly explained.

[0105] First, in step S51, the painting device 100 drives the second arm 12 by the painting robot 2 in accordance with the painting sequence determined by the painting sequence determination unit 420, and moves the first head 1A to a position facing the second region 202 of the object 200 shown in Figure 6, i.e., the starting position for painting by the first head 1A.

[0106] Subsequently, in step S52, the coating apparatus 100 opens the nozzle valve 26 of the first head 1A to discharge the liquid from the first head 1A, thereby coating the second region 202 of the object 200.

[0107] Next, in step S53, when painting by the first head 1A is completed, the painting apparatus 100 causes the painting robot 2 to drive the second arm 12 in accordance with the painting sequence determined by the painting sequence determination unit 420. By driving the second arm 12, the painting apparatus 100 moves the second head 1B to a position facing the first region 201 of the object 200, i.e., the painting start position by the second head 1B.

[0108] Subsequently, in step S54, the coating apparatus 100 opens the nozzle valve 26 of the second head 1B to discharge the liquid from the second head 1B, thereby coating the first region 201 of the object 200.

[0109] As described above, the coating apparatus 100 can coat the first region 201 and the second region 202 of the target object 200. The operation of the third example can suppress a decrease in the cleanability of the second nozzle surface 15B in the second head 1B having a large number of nozzles N2. Furthermore, in the third example, it is preferable that the standby time of the first head 1A having a small number of nozzles N1 is as short as possible, for example, a time that does not increase the dryness of the first head. Therefore, as long as the dryness of the first head 1A does not increase, the liquid ejection time of the second head 1B and the first head 1A may be the same, or the liquid ejection time of the second head 1B may be longer than the liquid ejection time of the first head 1A.

[0110] (Fourth example) A fourth example of the operation of the coating apparatus according to the first embodiment of the present invention will be described with reference to Figures 15A to 15D. Figure 15A is a first diagram showing priority parameters used by the coating apparatus according to the first embodiment of the present invention. Figure 15B is a second diagram showing priority parameters used by the coating apparatus according to the first embodiment of the present invention. Figure 15C is a third diagram showing priority parameters used by the coating apparatus according to the first embodiment of the present invention. Figure 15D is a fourth diagram showing priority parameters used by the coating apparatus according to the first embodiment of the present invention.

[0111] The fourth example differs from the first to third examples in that the order of painting by the first head 1A and the second head 1B is determined based on both the liquid ejection time and the number of nozzles of each of the first head 1A and the second head 1B.

[0112] Specifically, the liquid ejection time is T, the number of nozzles is N, and among the multiple heads including the first head 1A and the second head 1B, the number of nozzles of a certain head n is Nn, and the ejection time is Tn, where n is a natural number greater than or equal to 2. The coating apparatus 100 calculates a priority parameter Tn / Nn based on the ejection time Tn and the number of nozzles Nn.

[0113] 15A to 15D show maps of the priority parameter Tn / Nn, with the vertical axis representing the discharge time T and the horizontal axis representing the number of nozzles N. The longer the discharge time T and the smaller the number of nozzles N, the higher the priority. Information related to the priority parameter Tn / Nn, such as the maps shown in FIGS. 15A to 15D, is stored in a non-volatile memory, such as the HDD / SSD 404 shown in FIG. 4A. The coating sequence determination unit 420 of the coating apparatus 100 refers to the map stored in the non-volatile memory and determines the order of coating by the first head 1A and the second head 1B, so that the head with the larger value of the priority parameter Tn / Nn will paint first.

[0114] In FIG. 15B, point 1A-1 indicates the priority parameter Tn / Nn of the first head 1A, and point 1B-1 indicates the priority parameter Tn / Nn of the second head 1B. In the example shown in FIG. 15B, the liquid ejection time T of the first head 1A is longer than the liquid ejection time of the second head 1B, and the number of nozzles N of the first head 1A is smaller than the number of nozzles N of the second head 1B. Because the priority parameter Tn / Nn of the first head 1A is higher than the Tn / Nn of the second head 1B, the painting sequence determination unit 420 determines the painting sequence so that painting by the first head 1A is performed first, and then painting by the second head 1B is performed after painting by the first head 1A. The painting apparatus 100 can paint according to the flowchart shown in FIG. 10.

[0115] FIG. 15C illustrates a case in which the liquid ejection time T of the first head 1A and the liquid ejection time T of the second head 1B are the same, and the priority parameter Tn / Nn of the first head 1A is greater than the priority parameter Tn / Nn of the second head 1B. Point 1A-2 represents the priority parameter Tn / Nn of the first head 1A, and point 1B-2 represents the priority parameter Tn / Nn of the second head 1B. Because the priority parameter Tn / Nn of the first head 1A is higher than the Tn / Nn of the second head 1B, the painting sequence determination unit 420 determines the painting sequence such that painting by the first head 1A is performed first, followed by painting by the second head 1B. The painting apparatus 100 can paint according to the flowchart shown in FIG. 10.

[0116] FIG. 15D shows a case where the number of nozzles N of the first head 1A and the number of nozzles N of the second head 1B are the same. Point 1A-3 represents the priority parameter Tn / Nn of the first head 1A, and point 1B-3 represents the priority parameter Tn / Nn of the second head 1B. Because the priority parameter Tn / Nn of the first head 1A is higher than the Tn / Nn of the second head 1B, the painting sequence determination unit 420 determines the painting sequence so that painting is performed by the first head 1A first, and then by the second head 1B after painting by the first head 1A. The painting apparatus 100 can paint according to the flowchart shown in FIG.

[0117] The painting device 100 can obtain the same effect as the first example by performing the operation of the fourth example.

[0118] [Second embodiment] Next, a coating device according to a second embodiment will be described. Note that the same names and symbols as those in the previously described embodiments indicate the same or similar members or components, and detailed descriptions thereof will be omitted as appropriate.

[0119] 16 is a diagram showing an example of a first head 1A and a second head 1B provided in a coating apparatus according to a second embodiment of the present invention. The second embodiment of the present invention differs from the first embodiment of the present invention in that the first nozzle surface 15A of the first head 1A and the second nozzle surface 15B of the second head 1B face in the same direction.

[0120] 17A to 17C, a coating operation by the first head and the second head provided in the coating apparatus according to the second embodiment of the present invention will be described. FIG. 17A is a first diagram showing a coating operation by the first head and the second head provided in the coating apparatus according to the second embodiment of the present invention. FIG. 17B is a second diagram showing a coating operation by the first head and the second head provided in the coating apparatus according to the second embodiment of the present invention. FIG. 17C is a third diagram showing a coating operation by the first head and the second head provided in the coating apparatus according to the second embodiment of the present invention.

[0121] 17A to 17C, the first head 1A and the second head 1B eject liquids of different colors. In FIGS. 17A to 17C, a movement direction 211 indicates the direction in which the first head 1A and the second head 1B move. Furthermore, a width direction 212 indicates the direction intersecting with the movement direction 211.

[0122] First, as shown in FIG. 17A, the coating device 100 moves the first head 1A and the second head 1B in the movement direction 211, ejecting a liquid of a first color from the second head 1B, thereby coating the object 200 with the first color.

[0123] 17B, ​​the coating device 100 ejects liquid of a second color different from the first color from the first head 1A while moving the first head 1A and the second head 1B in a movement direction 211, thereby coating the target object 200 with the second color. In the example shown in Fig. 17B, in order to coat a width in the width direction 212 with the second color that is narrower than the width coated in Fig. 17A, the first head 1A and the second head 1B are moved in the movement direction 211 while being tilted relative to the movement direction 211.

[0124] Next, as shown in FIG. 17C, the coating device 100 moves the first head 1A and the second head 1B in the movement direction 211, ejecting a liquid of the first color from the second head 1B, thereby coating the object 200 with the first color.

[0125] In the example shown in Figures 17A to 17C, two-tone color painting is possible. In the second embodiment of the present invention, the painting apparatus 100 also determines the order of painting by the first head 1A and the second head 1B based on at least one of the liquid ejection time and the number of nozzles of each of the first head 1A and the second head 1B. This allows for obtaining the same effect as the painting apparatus according to the first embodiment of the present invention. Note that the number of colors of the liquid ejected from the first head 1A and the second head 1B is not limited to two, but may be three or more colors. Two or more types may also be used. For example, the liquids may be the same color but have different properties such as drying rate. The painting apparatus 100 is not limited to the first head 1A and the second head 1B, but may include three or more heads.

[0126] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments of the present invention without departing from the scope of the claims.

[0127] An embodiment of the present invention includes a coating system. For example, a coating system according to an embodiment of the present invention includes a coating apparatus 100 according to a first embodiment of the present invention and a maintenance and recovery unit 40 including cap members 41 that cover the nozzles 24 included in the first head 1A and the second head 1B. After the second head 1B performs coating, the maintenance and recovery unit 40 covers the nozzles 24 included in each of the first head 1A and the second head 1B with the cap members 41. This configuration reduces drying of liquid on the first nozzle surface 15A and the second nozzle surface 15B, and suppresses a decrease in the cleanability of the first nozzle surface 15A and the second nozzle surface 15B. Note that in this coating system, since the coating system includes the maintenance and recovery unit 40, the coating apparatus 100 does not necessarily include the maintenance and recovery unit 40.

[0128] The present invention is also applicable to painting processes performed for purposes other than applying color and design to vehicle bodies such as automobiles. For example, the painting process for an automobile body includes a primer coat, which aims to ensure adhesion and rust resistance of the paint film to the vehicle body substrate; a middle coat, which aims to ensure impact resistance and durability; and a top coat, which applies color and design. The painting apparatus of the present invention may be used for the primer coat or middle coat in addition to the top coat. Furthermore, if a protective layer, such as a clear coat, is applied after the top coat process for the purposes of gloss and paint film protection, the painting apparatus of the present invention may be used in the protective layer application process. Furthermore, if a peelable protective layer is applied to protect the painted surface after the automobile is shipped or in the factory, the painting apparatus of the present invention can also be used to apply the protective layer. The peelable protective layer may be any material that adheres to the painted surface of the vehicle body and chemically or physically protects the painted area from dust, metal powder, oil, salt, acid, ultraviolet light, etc., and is preferably formed from a material primarily composed of an acrylic copolymer, for example.

[0129] The present invention is also applicable to droplet ejection devices that eject droplets for purposes other than painting, such as marking devices that eject droplets onto an object to mark a specific location.

[0130] For example, aspects of the present invention are as follows. <1> The coating device has a first head and a second head, each of which includes at least one nozzle and sprays liquid from the nozzle to paint, and determines the order of painting by the first head and painting by the second head based on at least one of the liquid spraying time of each of the first head and the second head, the number of nozzles, and the waiting time of one head when the other head is spraying. <2> When the discharge time of the first head or the standby time of the second head is longer than the discharge time of the second head or the standby time of the first head, the first head paints before the second head, and the second head paints after the first head finishes painting. <1> 1 is a coating apparatus according to the present invention. <3> The first head applies paint again after the second head applies paint. <2> 1 is a coating apparatus according to the present invention. <4> When the number of the nozzles of the first head is smaller than the number of the nozzles of the second head, the first head paints before the second head. <1> From the above <3> The coating device is described in any one of the above. <5> a control unit that controls the ejection of liquid from each of the first head and the second head, and the control unit determines the order of coating by the first head and coating by the second head based on at least one of the ejection time, the number of nozzles, and the standby time of one head when the other head is ejecting, for each of the first head and the second head; <1> From the above <4> The coating device is described in any one of the above. <6> The discharge time refers to a coating time in each of the first head and the second head, and the standby time refers to a non-coating time in each of the first head and the second head. <1> From the above <5> The coating device is described in any one of the above. <7> The control unit determines the coating sequence so that the nozzle dryness is equal to or less than a threshold value. <5> 1 is a coating apparatus according to the present invention. <8> the first head includes a first nozzle surface on which the nozzles are provided, the second head includes a second nozzle surface on which the nozzles are provided, and the first head and the second head are arranged such that the first nozzle surface and the second nozzle surface face in different directions; <1> From the above <7> The coating device is described in any one of the above. <9> a maintenance and recovery unit including a cap member that covers the nozzles included in the first head and the second head, and the maintenance and recovery unit covers the nozzles included in each of the first head and the second head with a cap member after painting by the first head and the second head is completed; <1> From the above <8> The coating device is described in any one of the above. <10> The aforementioned <1> From the above <8> and a maintenance and recovery unit including a cap member that covers the nozzles included in the first head and the second head, wherein the maintenance and recovery unit covers the nozzles included in each of the first head and the second head with a cap member after painting by the first head and the second head is completed. [Explanation of symbols]

[0131] 1 head 2. Painting robot 3 Position detection unit 4 Liquid supply section 5. Control section 6 Liquid reservoir 7 Air supply section 8 liquid 9 Air regulator 10 Base 11 First Arm 12 Second Arm 13 Head Unit 16 Encoder Sensor 17 Robot drive unit 20. Housing 21 Supply Port 22 Collection Port 23 Dispensing Module 24 nozzles 240 nozzle holes 25 Nozzle plate 250 nozzle surface 26 Nozzle valve 27 Piezoelectric element 28 Liquid flow path 30 Support member 40 Maintenance and Recovery Department 40A First Maintenance and Recovery Department 40B Second Maintenance and Recovery Department 41 Cap member 100 painting equipment 200 objects 201 First Area 202 Second Realm 211 Direction of movement 212 Width direction 300 Computers 301 RIP section 302 Rendering Department 400 Controller 401 CPU 402 ROM 403 RAM 404 HDD / SSD 405 Interface 411 System Control Unit 412 Nozzle valve drive control unit 413 Discharge cycle signal generation section 414 Memory control unit 415 Data Storage Unit 416 Robot control signal generation unit 418 Maintenance and Recovery Control Unit 419 Painting Route Planning Department 420 Painting Order Determination Department 500 Head Control Device 600 Robot control device 700A input device S System Bus [Prior art documents] [Patent documents]

[0132] [Patent Document 1] Japanese Patent Application Publication No. 2023-140457

Claims

1. The apparatus has a first head and a second head, each of which includes at least one nozzle and ejects a liquid from the nozzle to perform painting, A coating device that determines the order of coating by the first head and the second head based on at least one of the liquid ejection time of each of the first head and the second head, the number of nozzles, and the standby time of one head when the other head is ejecting.

2. the first head applies paint before the second head when the ejection time of the first head or the standby time of the second head is longer than the ejection time of the second head or the standby time of the first head; 2. The coating device according to claim 1, wherein the second head performs coating after the first head finishes coating.

3. 3. The coating device according to claim 2, wherein the first head coats again after the second head coats.

4. 2. The coating device according to claim 1, wherein the first head coats before the second head when the number of the nozzles in the first head is smaller than the number of the nozzles in the second head.

5. a control unit that controls the ejection of liquid from each of the first head and the second head, 2. The coating device according to claim 1, wherein the control unit determines the order of coating by the first head and the second head based on at least one of the discharge time, the number of nozzles, and a standby time of one head when the other head is discharging, for each of the first head and the second head.

6. 2. The coating device according to claim 1, wherein the discharge time refers to a coating time for each of the first head and the second head, and the standby time refers to a non-coating time for each of the first head and the second head.

7. The coating device according to claim 5 , wherein the control unit determines the coating sequence so that the nozzle dryness is equal to or less than a threshold value.

8. the first head includes a first nozzle surface on which the nozzles are provided, the second head includes a second nozzle surface on which the nozzles are provided, The coating device according to claim 1 , wherein the first head and the second head are arranged so that the first nozzle surface and the second nozzle surface face in different directions.

9. a maintenance and recovery unit including a cap member that covers the nozzles included in the first head and the second head; 2. The coating device according to claim 1, wherein the maintenance and recovery unit covers the nozzles included in each of the first head and the second head with a cap member after coating by the first head and the second head is completed.

10. A coating device according to any one of claims 1 to 8; a maintenance and recovery unit including a cap member that covers the nozzles included in the first head and the second head, A painting system in which the maintenance and recovery unit covers the nozzles included in each of the first head and the second head with a cap member after painting by the first head and the second head is completed.

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