Painting robot cleaning system

Abstract

To provide a cleaning system for a painting robot, capable of suppressing a decrease in the cleaning performance of a paint circulation path and an increase in cleaning time even when a return flow path from a painting head is long. [Solution] The cleaning system 1 of the painting robot 10 comprises a painting head unit 30 equipped with an inkjet type painting head 31, a robot arm R1, a cap 93 that seals at least a portion of the nozzle forming surface 32, a cap moving mechanism 94, a paint supply path 52, a return flow path 53 that recovers paint or cleaning fluid toward at least a paint tank 57 separate from the robot arm R1, a pressurizing means that pressurizes the cleaning fluid, a cleaning suction means that sucks the cleaning fluid, and a control means that controls the operation of the pressurizing means and the cleaning suction means, and during cleaning, the control means activates the cap moving mechanism 94 to seal the nozzle forming surface 32 with the cap 93, and then activates the pressurizing means and the cleaning suction means.

Description

[Technical Field]

[0001] The present invention relates to a cleaning system for a painting robot. [Background technology]

[0002] Among painting robots that paint vehicles, there is one such as that shown in Patent Document 1. Patent Document 1 discloses a paint circulation path in an inkjet type painting device, which includes an ink tank (11), an outgoing path (12) that transports ink from the ink tank (11) to an inkjet head (10), and a returning path (13) that returns ink from the inkjet head (10) to the ink tank (11).

[0003] In this configuration, during cleaning, ink is passed from the forward path (12) to the return path (13), bypassing the inkjet head (10), and cleaning liquid is passed to the inkjet head (10) using a first cleaning liquid flow path (15) and a second cleaning liquid flow path (16), which are separate cleaning liquid lines (FIG. 2A). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-030047 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration disclosed in Patent Document 1, the return path (13), which is the ink return flow path, can be cleaned by allowing cleaning liquid to flow through the return path (13) during cleaning. However, if the distance between the ink tank (11) and the inkjet head (10) becomes longer, the return path (13) also becomes longer, which reduces the return of cleaning liquid from the head and reduces the cleaning efficiency of the entire paint circulation path.

[0006] The present invention has been made based on the above circumstances, and aims to provide a cleaning system for a painting robot that can suppress a decrease in the cleaning performance of the paint circulation path and an increase in cleaning time even if the return flow path from the painting head is long. [Means for solving the problem]

[0007] In order to solve the above problems, according to a first aspect of the present invention, there is provided a cleaning system for a painting robot that paints a painting portion of a vehicle, comprising: a painting head unit having an inkjet type painting head with an array of nozzles that eject paint; a robot arm that has the painting head unit attached to its tip and moves the painting head unit to a desired position; a cap that seals at least a part of the nozzle forming surface where the nozzles are exposed; a cap moving mechanism that moves the nozzle forming surface relative to the cap to seal the nozzle forming surface; a paint supply path that supplies paint or cleaning fluid toward the painting head; and a paint discharge side of the painting head that is connected to at least the robot arm. a return flow path that recovers paint or cleaning fluid toward a separate paint tank; a pressurizing means that pressurizes the cleaning fluid supplied toward the paint head in one of the paint supply path and the return flow path; a cleaning suction means that sucks the cleaning fluid discharged from the paint head in the other of the paint supply path and the return flow path; and a control means that controls the operation of the pressurizing means and the cleaning suction means, wherein, when cleaning using cleaning fluid, the control means operates a cap moving mechanism to seal the nozzle forming surface with a cap, and then operates the pressurizing means and the cleaning suction means, thereby increasing the discharge speed of the cleaning fluid compared to when only the pressurizing means is operated. [Effects of the Invention]

[0008] According to the present invention, a cleaning system for a painting robot can be provided that can suppress a decrease in the cleaning performance of the paint circulation path and an increase in cleaning time even if the return flow path from the painting head is long. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a top view showing a configuration of a painting robot according to an embodiment of the present invention; [Figure 2] FIG. 2 is a view of the painting robot shown in FIG. 1 as seen from the upstream side of the painting line. [Figure 3] FIG. 2 is a view of the painting robot shown in FIG. 1 as seen from the vehicle body side. [Figure 4] FIG. 2 is a diagram showing a schematic configuration of a cleaning system for the painting robot shown in FIG. [Figure 5] 2 is a front view of a nozzle forming surface that ejects paint, of a paint head unit provided in the paint robot shown in FIG. 1. FIG. [Figure 6] 4 is a plan view showing the configuration of a nozzle formation surface of another paint head unit different from the paint head unit shown in FIG. 3. FIG. [Figure 7] 2 is a diagram showing a schematic configuration for supplying paint to each nozzle of a painting head provided in the painting robot shown in FIG. 1. FIG. [Figure 8] FIG. 2 is a diagram showing a schematic control configuration of the cleaning system of the painting robot shown in FIG. 1, focusing on a control unit. [Figure 9] 3 is a diagram showing a cleaning chart for cleaning the internal flow passages in the painting head of the painting robot shown in FIG. 1. FIG. [Figure 10] FIG. 10 is a diagram showing a schematic configuration of a cleaning system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] A cleaning system 1 for a painting robot 10 according to one embodiment of the present invention will be described below with reference to the drawings. The cleaning system 1 cleans a painting system that paints an object by discharging paint onto the object. Therefore, the cleaning system 1 also corresponds to a painting system that paints an object.

[0011] In the following description, where necessary, the X direction will be the longitudinal direction of the nozzle forming surface 32 (painting head 31), the X1 side will be the right side in Fig. 3, and the X2 side will be the left side in Fig. 3. The Y direction will be the short side (width direction) of the nozzle forming surface 32 (painting head 31), the Y1 side will be the upper side in Fig. 3, and the Y2 side will be the lower side in Fig. 3.

[0012] (1. Overview of Painting Robot 10) The washing system 1 of this embodiment "paints" objects to be painted, such as vehicles FR (see FIGS. 1 and 2) or vehicle parts (hereinafter, vehicle parts that are part of the vehicle FR will also be referred to as vehicles FR) located on a painting line in an automobile manufacturing factory, and aims to form a paint film on the surface of the object to be painted to protect the surface and provide a beautiful appearance. Therefore, it is necessary to paint the vehicles FR that move along the painting line at predetermined intervals within a certain time with the desired paint quality.

[0013] Furthermore, the cleaning system 1 of this embodiment is capable of not only forming the above-described coating film but also forming various designs and images on objects to be painted, such as a vehicle FR, etc. Note that the objects to be painted are not limited to vehicles FR and vehicle parts, but may be any parts other than automobiles (for example, exterior parts of airplanes and trains) that require painting.

[0014] (1-1. Overall Configuration of the Cleaning System 1 of the Painting Robot 10) Fig. 1 is a top view showing the configuration of a painting robot 10 according to one embodiment of the present invention. Fig. 2 is a view of the painting robot 10 shown in Fig. 1 as seen from the upstream side of the painting line. Fig. 3 is a view of the painting robot shown in Fig. 1 as seen from the vehicle body side. Fig. 4 is a diagram showing the schematic configuration of a cleaning system 1 for the painting robot 10 shown in Fig. 1. As shown in Figs. 1 to 4, the cleaning system 1 includes the painting robot 10 and a paint supply and cleaning mechanism 50.

[0015] (1-2. About Painting Robot 10) As shown in FIG. 1, the painting robot 10 includes, for example, a robot arm R1, a moving device 15, and a painting head unit 30. The robot arm R1 is composed of a multi-axis arm having a base 21 and multiple (two in FIG. 1) arm members 22 and 23. The base 21 includes a fixed part 24 fixed to a moving base 16 (described later) and a rotating part 25 rotatable relative to the fixed part 24. The fixed part 24 includes a motor (not shown) therein. Driven by the motor (not shown), the rotating part 25 rotates around a rotation center in a direction perpendicular to the floor of the painting line (the z direction or -z direction in FIG. 2 or FIG. 3).

[0016] Hereinafter, of the multiple arm members 22, 23, the arm member 22 connected to the rotating portion 25 will be referred to as a first rotating arm 22, and the arm member 23 connected to the first rotating arm 22 will be referred to as a second rotating arm 23.

[0017] One end of the first rotating arm 22 in the extension direction of the first rotating arm 22 is connected to a movable shaft 26 provided on the rotating unit 25. A motor (not shown) is provided on the movable shaft 26 provided on the rotating unit 25, and the connected first rotating arm 22 is rotated on a plane perpendicular to the floor surface of the coating line (for example, the yz plane when the robot arm R1 is in the state of FIG. 2).

[0018] In the extension direction of the first pivot arm 22, the second pivot arm 23 is connected via a movable shaft 27 to the other end opposite to the one end connected to the movable shaft 26 of the rotating unit 25. A motor (not shown) is provided on the movable shaft 27, and the second pivot arm 23 connected to it is rotated on a plane perpendicular to the floor of the coating line (for example, the yz plane when the robot arm R1 is in the state of FIG. 2). Although not shown, the central axis of the movable shaft 26 of the rotating unit 25 and the central axis of the movable shaft 27 provided on the first pivot arm 22 are parallel to each other.

[0019] A wrist unit 28 is provided at the other end in the extension direction of the second pivot arm 23. The wrist unit 28 holds the paint head unit 30. Although detailed configuration will be omitted, the wrist unit 28 has multiple (three in this example) motors (not shown) whose drive shafts have different axial directions, and by driving one of these motors, the held paint head unit 30 is rotated around one of the multiple shafts of the wrist unit 28 as the rotation center. Note that it is preferable that the number of shafts is two or more.

[0020] The moving device 15 is installed on the floor of the painting room, for example, and moves the robot arm R1 back and forth in one direction (the x-direction or the -x-direction in FIG. 1 or 3) along the floor of the painting room. The direction in which the robot arm R1 is moved by the moving device 15 is the painting direction (main scanning direction) of the painting head 31, which will be described later. The moving device 15 has a moving table 16 to which a base 21 of the robot arm R1 is fixed, rails 17 that guide the movement of the moving table 16, and a drive mechanism 18 that moves the moving table 16 back and forth along the rails 17.

[0021] The rail 17 is fixed to the floor of the coating room by a frame (not shown) in a state in which the extending direction of the rail 17 is along the x direction or the −x direction in FIG.

[0022] The drive mechanism 18 is fixed to, for example, the floor of a paint booth by a frame (not shown). The drive mechanism 18 is, for example, composed of a drive motor (not shown), a drive sprocket 18a, a driven sprocket 18b, and a drive belt 18c wound around these sprockets 18a, 18b. However, the drive mechanism 18 is not limited to this mechanism and may have any configuration as long as it is capable of moving the base 21 along the rails 17.

[0023] (1-3. About the painting head unit 30) Next, the painting head unit 30 provided in the painting robot 10 will be described. Fig. 5 is a diagram showing a front view of the nozzle forming surface 32, from which paint is ejected, of the painting head 31 of the painting head unit 30. As shown in Fig. 5, the painting head unit 30 is equipped with a head cover (not shown), and various components, including the painting head 31, are housed within the head cover. The painting head 31 is provided with a number of nozzles 33 for ejecting paint.

[0024] 5, the openings of a plurality of nozzles 33 are exposed on the surface (nozzle forming surface 32) of the paint head 31 from which paint is ejected. In the following description, the openings of the nozzles 33 will also be referred to as nozzles 33.

[0025] The nozzle forming surface 32 is provided with a plurality of nozzle rows 34 in which the nozzles 33 are aligned in a direction inclined with respect to the longitudinal direction of the paint head unit 30. In this embodiment, the nozzle rows 34 include a first nozzle row 34A located on one side (Y2 side) in the main scanning direction (Y direction) and a second nozzle row 34B located on the other side (Y1 side) in the main scanning direction.

[0026] When discharging paint, the drive timing of each nozzle 33 is controlled so that droplets discharged from nozzles 33 in the second nozzle row 34B land between droplets discharged from adjacent nozzles 33 in the first nozzle row 34A, thereby improving dot density during coating.

[0027] A cap 93, which will be described later, can seal the nozzle surface 32 from the outside by coming into contact with the nozzle surface 32. In this state, a vacuum ejector 91, which will be described later, can be operated to perform a cleaning operation, which will be described later.

[0028] 5, the arrangement of the nozzles 33 in the first nozzle row 34A and the arrangement of the nozzles 33 in the second nozzle row 34B are inclined with respect to the widthwise direction (Y direction; main scanning direction) of the paint head 31. However, such an arrangement of the nozzles 33 does not have to be adopted. For example, the nozzle row 34 may be arranged along the widthwise direction (Y direction) of the paint head 31. Furthermore, the nozzle row 34 may not be divided into the first nozzle row 34A and the second nozzle row 34B in the widthwise direction (Y direction; main scanning direction) of the paint head 31, but may remain as a single nozzle row 34, or may be divided into three or more nozzle rows.

[0029] An internal flow path 36 (see FIG. 7) for flowing paint is provided inside the coating head 31. A nozzle pressurizing chamber 37 (see FIG. 7) is also provided inside the coating head 31, and a piezoelectric substrate 35 (see FIG. 7) is arranged on one of the wall surfaces of the nozzle pressurizing chamber 37 to change the volume of the nozzle pressurizing chamber 37 and eject paint from the nozzle 33. Therefore, by applying a voltage to the piezoelectric substrate 35 from the outside, the piezoelectric substrate 35 expands and contracts, changing the volume of the nozzle pressurizing chamber 37 and enabling paint to be ejected from the nozzle 33.

[0030] The paint head 31 is not limited to the configuration shown in Fig. 5. For example, as shown in Fig. 6, a plurality of nozzles 33 may be arranged along the short side direction (width direction; Y direction) of the paint head 31 to form a nozzle row 34. Furthermore, when painting the vehicle FR using the paint head 31 shown in Fig. 6, painting may be performed with the longitudinal direction of the paint head 31 slightly tilted with respect to the main scanning direction of the paint head 31.

[0031] For example, if the nozzle rows 34 in the configuration of the paint head 31 shown in Fig. 5 are inclined at an angle α with respect to the main scanning direction, then the longitudinal direction of the paint head 31 in Fig. 6 can be inclined at the angle α with respect to the main scanning direction of the paint head 31. When inclined in this way, painting equivalent to that of the paint head 31 shown in Fig. 5 can be achieved simply by adjusting the timing at which paint is ejected from each nozzle 33.

[0032] Fig. 7 is a diagram showing a schematic configuration for supplying paint to each nozzle 33 of the paint head 31. As shown in Fig. 7, the paint head 31 has an internal flow path 36. The internal flow path 36 is a flow path that supplies paint to the nozzle pressurizing chamber 37 via a paint supply path 52, which will be described later. Note that Fig. 7 shows one internal flow path 36. However, since the paint head 31 has a large number of nozzles 33 formed therein, the paint head 31 is provided with a large number of internal flow paths 36.

[0033] The nozzle pressurizing chambers 37 are provided in a number corresponding to the number of nozzles 33, and the paint inside can be ejected from the nozzles 33 by driving the piezoelectric substrate 35. The nozzle pressurizing chambers 37 are also connected to a return flow path 53 (described later) via an internal flow path 36 in the coating head 31, such as a nozzle discharge flow path (not shown). Therefore, paint not ejected from the nozzles 33 is returned to the return flow path 53.

[0034] With this configuration, paint supplied from a paint supply / cleaning mechanism 50 (see FIG. 8) described later passes through the internal flow path 36 and the nozzle pressurizing chamber 37, and is then ejected from the nozzle 33. Furthermore, paint that is not ejected from the nozzle 33 passes from the nozzle pressurizing chamber 37 through the internal flow path 36, and is returned to a return flow path 53 described later.

[0035] In the painting robot 10 and cleaning system 1 configured as described above, the section from the movable platform 16 through the robot arm R1 to the painting head unit 30 (robot main body) is movable along rails 17. On the other hand, the cleaning tank 63 and drainage tank 65 that make up the cleaning system 1 are not mounted on the robot arm R1, but are installed in the location (installation surface, etc.) where the painting robot 10 is installed. For this reason, as shown in Figure 1, the length of the return flow path 53 is long, and the paint supply path 52 is also often long.

[0036] In this configuration, where at least the length of the return flow path 53 is long and the length of the paint supply path 52 is often long, the discharge capacity (suction capacity) of the cleaning fluid described below is insufficient when cleaning each part of the paint supply and cleaning mechanism 50, which often leads to a decrease in cleaning performance and an increase in cleaning time. However, the configuration described below aims to solve the problems of a decrease in cleaning performance and an increase in cleaning time.

[0037] (1-4. About the paint supply and cleaning mechanism 50) Next, we will explain the paint supply / cleaning mechanism 50. As shown in Fig. 4, the paint supply / cleaning mechanism 50 includes a paint circulation path 51, a paint tank 57, a removal filter 58, a degassing module 59, a supply pump 61, a suction pump 62, a cleaning tank 63, a delivery pump 64, a drain tank 65, a compressor 66, a cleaning switching valve 67, first to fourth three-way valves 71 to 74, first to sixth switching valves 81 to 86, a first vacuum ejector 91, a second vacuum ejector 92, a cap 93, a cap moving mechanism 94 (see Fig. 8), and other pipelines, etc.

[0038] The paint circulation path 51 is a flow path for circulating the paint, and includes a paint supply path 52, a return path 53, a bypass path 54, an external supply path 55, and a second bypass path 56. The paint supply path 52 is a flow path for supplying paint that has been supplied from the external supply path 55 or returned from the return path 53 toward the paint head 31, and is connected to the internal path 36 within the paint head 31 described above.

[0039] Here, each component of the paint supply and cleaning mechanism 50, including the paint circulation path 51, can flow cleaning liquid (cleaning fluid) in addition to paint, but in the following description, it will be described as simply flowing "paint."

[0040] The return flow path 53 is connected to the internal flow path 36 in the paint head 31 described above, and is a flow path for returning paint that has not been ejected from the paint head 31 to the paint tank 57.

[0041] The bypass flow path 54 is a flow path that connects the paint supply path 52 and the return flow path 53. In other words, the bypass flow path 54 is provided in parallel with the paint head 31, and when paint is not being ejected from the paint head 31, the paint is caused to flow into the bypass flow path 54 by switching the operation of a second three-way valve 72 and a third three-way valve 73, which will be described later.

[0042] The external supply path 55 is a pipe for supplying paint supplied from a paint storage portion such as a circulation tank to the paint tank 57 .

[0043] The second bypass flow path 56 is a flow path that connects the first switching valve 81 and the sixth switching valve 86, forms a circulation path that includes the paint tank 57, and is a flow path for performing cleaning in this circulation path.

[0044] The paint tank 57 is a portion for temporarily storing the paint supplied from the external supply path 55. The paint tank 57 may also have a function for removing air bubbles contained in the paint. The paint tank 57 is provided, for example, in a stable position outside the robot arm R1 where the posture of the paint tank 57 does not change. The paint tank 57 is connected to the paint supply path 52 so as to be able to supply paint, and is also connected to the return path 53 so as to be supplied with paint from the return path 53.

[0045] The removal filter 58 removes foreign matter contained in the paint flowing through the paint supply path 52. The removal filter 58 ensures that the paint head 31 continues to operate normally by reliably removing coarse foreign matter and pigment aggregates from paint that contains, for example, pigment. The removal filter 58 is disposed in the paint supply path 52, between the second selector valve 82 and the third selector valve 83.

[0046] The degassing module 59 is disposed downstream of the removal filter 58 in the paint supply passage 52, and is a member for removing (degassing) dissolved gases dissolved in the paint. The degassing module 59 is disposed in the paint supply passage 52 between the third switching valve 83 and the fourth switching valve 84.

[0047] The supply pump 61 is a means for applying a positive pressure to the paint flowing through the paint supply passage 52 toward the downstream side of the supply pump 61 .

[0048] It is preferable to use a gear pump as the supply pump 61, which can control the amount of paint supplied by controlling the rotation speed. In this case, it is possible to reverse the flow of paint and cleaning liquid by rotating the supply pump 61, which is a gear pump, in the reverse direction. However, a pump other than a gear pump may also be used as the supply pump 61.

[0049] The suction pump 62 is a means for applying negative pressure to the paint flowing through the return flow path 53 on the upstream side of the suction pump 62. The suction pump 62 corresponds to the suction means.

[0050] As with the supply pump 61, it is preferable to use a gear pump as the suction pump 62, which can control the amount of paint supplied by controlling the rotation speed. In this case, it is possible to reverse the flow of paint and cleaning liquid by rotating the gear pump suction pump 62 in the reverse direction. However, the suction pump 62 may be a pump other than a gear pump.

[0051] The cleaning tank 63 is a part that stores cleaning liquid and supplies cleaning liquid to each part of the paint supply / cleaning mechanism 50 and to be used when cleaning the painting head 31. The delivery pump 64 is a part that draws in cleaning liquid stored in the cleaning tank 63 and delivers the drawn-in cleaning liquid to the cleaning switching valve 67. The delivery pump 64 corresponds to the pressurizing means.

[0052] The drainage tank 65 is a portion for storing the cleaning liquid (drainage) discharged after cleaning each portion of the paint supply and cleaning mechanism 50 and the coating head 31.

[0053] The compressor 66 is a part that sends out cleaning air toward the cleaning switchover valve 67. The cleaning switchover valve 67 also has a plurality of valve parts, including a valve part 67a to which a flow path extending from the cleaning tank 63 is connected, a valve part 67b to which a flow path extending from the compressor 66 is connected, and a valve part 67c to which flow paths extending to first to sixth switchover valves 81 to 86, which will be described later, are connected. These plurality of valve parts are individually controlled to open and close by a cleaning control part 150, which will be described later. By this opening and closing control, the cleaning liquid from the cleaning tank 63 and the air from the compressor 66 are alternately sent into the paint supply path 52 or the return path 53 in the paint circulation path 51.

[0054] The first three-way valve 71 is disposed between the paint tank 57 and the first switching valve 81 in the paint supply path 52, and is also connected to a branch path (reference numeral omitted) leading to the drainage tank 65. This first three-way valve 71 is capable of blocking the flow of paint or cleaning liquid between (a) the paint tank 57 side, (b) the first switching valve 81 side, or (c) the drainage tank 65 side. Therefore, the paint or cleaning liquid can flow through the remaining two unblocked flow paths (the same applies to the second to fourth three-way valves 72 to 74 described below).

[0055] Similarly, the second three-way valve 72 is disposed between the fourth switching valve 84 and the paint head 31, and is also connected to one end of the bypass flow path 54. This second three-way valve 72 is capable of blocking the flow of paint or cleaning liquid between (a) the fourth switching valve 84 side, (b) the paint head 31 side, or (c) the bypass flow path 54 side.

[0056] The third three-way valve 73 is disposed between the paint head 31 and the fifth switching valve 85, and is also connected to the other end of the bypass flow path 54. The third three-way valve 73 is capable of blocking the flow of paint or cleaning liquid between (a) the paint head 31 side, (b) the fifth switching valve 85 side, or (c) the bypass flow path 54 side.

[0057] The fourth three-way valve 74 is disposed between the sixth switching valve 86 and the paint tank 57, and is further connected to a branch path (reference numeral omitted) leading to the drainage tank 65. The fourth three-way valve 74 is capable of blocking the flow of paint or cleaning liquid between (a) the sixth switching valve 86 side, (b) the paint tank 57 side, or (c) the drainage tank 65 side.

[0058] The first switching valve 81 is disposed in the paint supply passage 52 between the first three-way valve 71 and the second switching valve 82. The first switching valve 81 has four valve sections 81a to 81d, and can switch the flow paths of the liquid (paint, cleaning liquid) and air (air used during cleaning) depending on the open / close states of the valve sections 81a to 81d. Specifically, the valve section 81a is connected to the upstream side of the paint supply passage 52, and the valve section 81b is connected to the downstream side of the paint supply passage 52. The valve section 81c is connected to the cleaning switching valve 67, which can be switchably connected to either the cleaning tank 63 or the compressor 66. The valve section 81d is connected to the second bypass passage 56.

[0059] Therefore, when paint is supplied from the paint tank 57 to the paint head 31 or when paint is circulated, the valves 81a and 81b are opened, and paint from the paint tank 57 flows downstream of the paint supply path 52. During cleaning, when either one of the valves 81a and 81b and the valve 81c is opened, the cleaning liquid supplied from the cleaning tank 63 or the air supplied from the compressor 66 flows into the flow path connected to the valve that was opened. In the following description, the term "cleaning fluid" will refer to at least one of the cleaning liquid and air used during cleaning.

[0060] Furthermore, the valve portion 81d is connected to a valve portion 86d of a sixth switching valve 86 (described later) that is arranged in the return flow path 53 via the second bypass flow path 56. Therefore, for example, by opening the valve portions 81a and 81d, a circulation path is formed that connects the upstream side of the paint supply path 52 (the side connected to the paint tank 57), the second bypass flow path 56, and the downstream side of the return flow path 53 (the side connected to the paint tank 57).

[0061] The second selector valve 82 is connected to the paint supply passage 52 downstream of the first selector valve 81 and upstream of the removal filter 58. Like the first selector valve 81, the second selector valve 82 also has four valve sections 82a to 82d, and can switch the flow paths of liquids (paint, cleaning liquid) and gases (air used during cleaning) depending on the open / closed states of the valve sections 82a to 82d. Specifically, the valve section 82a is connected to the upstream side of the paint supply passage 52, and the valve section 82b is connected to the downstream side of the paint supply passage 52. The valve section 82c is connected to a cleaning selector valve 67 that can be switchably connected to either the cleaning tank 63 or the compressor 66. The valve section 82d is connected to the drain tank 65 via a vacuum ejector 91.

[0062] Therefore, when paint is supplied from the paint tank 57 to the paint head 31 or when paint is circulating, the valves 82a and 82b are opened, and the paint from the paint tank 57 flows downstream of the paint supply passage 52. When cleaning, when either one of the valves 82a and 82b and the valve 82c is opened, the cleaning fluid flows through the opened valve into the passage connected to that valve.

[0063] The third switching valve 83 is connected to the paint supply path 52 downstream of the second switching valve 82 and the removal filter 58 and upstream of the degassing module 59. Like the first switching valve 81, the third switching valve 83 also has four valve sections 83a to 83d, and can switch the flow paths of the liquid (paint, cleaning liquid) and the gas (air used during cleaning) depending on the open / closed states of the valve sections 83a to 83d. Specifically, the valve section 83a is connected to the upstream side of the paint supply path 52, and the valve section 83b is connected to the downstream side of the paint supply path 52. The valve section 83c is connected to the cleaning switching valve 67, which can be switchably connected to either the cleaning tank 63 or the compressor 66. The valve section 83d is connected to the drainage tank 65.

[0064] Therefore, when paint is supplied from the paint tank 57 to the paint head 31 or when paint is circulating, the valves 83a and 83b are opened, and the paint from the paint tank 57 flows downstream of the paint supply passage 52. When cleaning, when either one of the valves 83a and 83b and the valve 83c is opened, the cleaning fluid flows through the opened valve into the passage connected to that valve.

[0065] The fourth switching valve 84 is connected to the paint supply passage 52 downstream of the third switching valve 83 and the degassing module 59 and upstream of the second three-way valve 72. Unlike the first switching valve 81, the fourth switching valve 84 has six valve sections 84a to 84f, and can switch the flow paths of the liquid (paint, cleaning liquid) and the gas (air used during cleaning) depending on the open / closed state of these valve sections 84a to 84f.

[0066] Specifically, valve portion 84a is connected to the upstream side of paint supply passage 52, and valve portion 84b is connected to the downstream side of paint supply passage 52. Therefore, when valve portion 84a and valve portion 84b are opened, paint from the upstream side of paint supply passage 52 flows to the second three-way valve 72 side on the downstream side of paint supply passage 52. Valve portion 84a is also connected to valve portion 84f independently of valve portions 84b, 84c, and 84e. Therefore, when valve portion 84c or 84e and valve portion 84b are opened and cleaning liquid, air, or paint is flowing through these valve portions, valve portion 84a can be connected to valve portion 84f independently of the flow.

[0067] Furthermore, the valve section 84c is connected to a cleaning switching valve 67 that can be switched to connect to either the cleaning tank 63 or the compressor 66. Therefore, during cleaning, when the valve section 84a or 84b and the valve section 84c are opened, the cleaning fluid flows through the opened valve section into the flow path connected to the valve section.

[0068] Furthermore, valve portion 84d is connected to the cleaning switching valve 67 separately and independently from valve portion 84c. The flow path of valve portion 84d is not connected to valve portions 84b, 84c, and 84e, but is connected only to valve portions 84a and 84f. For example, when valve portion 84d and valve portion 84f are opened, the cleaning fluid flows into the drainage tank 65 via the opened valve portion 84f.

[0069] Furthermore, the valve unit 84e is connected to the drain tank 65 via a first vacuum ejector 91, which will be described later. Therefore, when either the valve unit 84a or the valve unit 84b described above is opened and the first vacuum ejector 91 is operated with the valve unit 84e open, the cleaning fluid used for cleaning is discharged into the drain tank 65 via the valve unit 84e and the vacuum ejector 91.

[0070] Valve portion 84f is also connected to drainage tank 65. The flow path of valve portion 84f is not connected to valve portions 84b, 84c, and 84e, but is connected to valve portions 84a and 84d. When valve portions 84a and 84f are opened, drained paint from the upstream side of paint supply path 52 flows into drainage tank 65 via valve portions 84a and 84f.

[0071] The fifth switching valve 85 is connected to the return flow path 53 downstream of the third three-way valve 73 and upstream of the suction pump 62. Like the fourth switching valve 84, the fifth switching valve 85 also has six valve portions 85a to 85f, and can switch the flow paths of the liquid (paint, cleaning liquid) and air depending on the open / closed state of these valve portions 85a to 85f.

[0072] Specifically, valve portion 85a is connected to the upstream side of return flow path 53, and valve portion 85b is connected to the downstream side of return flow path 53. Therefore, when valve portion 85a and valve portion 85b are opened, paint from the upstream side of return flow path 53 flows toward suction pump 62 on the downstream side of return flow path 53. Valve portion 85b is also connected to valve portion 85f independently of valve portions 85a, 85c, and 85e. Therefore, when valve portion 85c or 85e and valve portion 85b are opened to allow cleaning fluid or paint to flow through these valve portions, valve portion 85b can be connected to valve portion 85f independently of the flow.

[0073] Furthermore, the valve portion 85c is connected to the cleaning switching valve 67. Therefore, during cleaning, when either the valve portion 85a or the valve portion 85b and the valve portion 85c are opened, the cleaning fluid flows through the opened valve portion into the flow path connected to that valve portion.

[0074] Furthermore, valve portion 85d is connected to the cleaning switching valve 67 separately and independently from the above-mentioned valve portion 85c. The flow path of valve portion 85d is not connected to valve portions 85a, 85c, and 85e, but is connected only to valve portions 85b and 85f. For example, when valve portion 85d and valve portion 85f are opened, the cleaning fluid flows into the drainage tank 65 via the opened valve portion 85f.

[0075] Furthermore, the valve unit 85e is connected to the drain tank 65 via a second vacuum ejector 92, which will be described later. Therefore, when either the valve unit 85a or the valve unit 85b described above is opened and the second vacuum ejector 92 is operated with the valve unit 85e open, the cleaning fluid used for cleaning is discharged into the drain tank 65 via the valve unit 85e and the second vacuum ejector 92.

[0076] Furthermore, valve portion 85f is connected to valve portions 85b and 85d and drainage tank 65. The flow path of valve portion 85f is not connected to valve portions 85a, 85c, and 85e, but is connected to valve portions 85b and 85d. When valve portions 85b and 85f are opened, the drained paint on the downstream side of return flow path 53 flows into drainage tank 65 via valve portions 85b and 85f.

[0077] The sixth switching valve 86 is disposed in the return flow path 53 between the suction pump 62 and the fourth three-way valve 74. The sixth switching valve 86 has four valve sections 86a to 86d, and can switch the flow paths of the liquid (paint, cleaning liquid) and air depending on the open / close states of the valve sections 86a to 86d. Specifically, the valve section 86a is connected to the upstream side of the return flow path 53, and the valve section 86b is connected to the downstream side of the return flow path 53. The valve section 86c is connected to the cleaning switching valve 67, which can be switchably connected to either the cleaning tank 63 or the compressor 66. The valve section 86d is connected to the second bypass flow path 56.

[0078] Therefore, when paint is supplied from the paint tank 57 to the paint head 31 or when paint is circulating, the valves 86a and 86b are opened, and paint from the paint head 31 side (upstream side) flows to the downstream side of the return flow path 53. During cleaning, when either one of the valves 86a and 86b and the valve 86c is opened, the cleaning fluid flows through the opened valve into the flow path connected to that valve.

[0079] As described above, the valve portion 86d is connected to the valve portion 81d of the first selector valve 81 via the second bypass flow path 56. Therefore, when the valve portions 81a and 81d of the first selector valve 81 are opened and the valve portions 86d and 86b of the sixth selector valve 86 are opened, the second bypass flow path 56 connecting the valve portions 81d and 86d is opened. This forms a circulation path through which the paint circulates through the paint tank 57, the first selector valve 81, the second bypass flow path 56, and the sixth selector valve 86 in this order.

[0080] The first vacuum ejector 91 is disposed midway through the conduit connecting the valve unit 84e and the drain tank 65. The first vacuum ejector 91 is a device that discharges fluid by generating a vacuum. When the first vacuum ejector 91 is activated, paint or cleaning fluid can be discharged from the coating head 31 side at a predetermined pressure when the valve units 84b and 84e are open.

[0081] The second vacuum ejector 92 is disposed midway through the conduit connecting the valve unit 85e and the drain tank 65. The second vacuum ejector 92 is a device that discharges fluid by generating a vacuum, similar to the first vacuum ejector 91. When the second vacuum ejector 92 is in operation, paint or cleaning fluid can be discharged from the coating head 31 side at a predetermined pressure when the valve units 85a and 85e are open.

[0082] The first vacuum ejector 91 and the second vacuum ejector 92 are provided so as to have a suction force sufficiently higher than that of the suction pump 62. More specifically, the cleaning control unit 150 controls the operation of the first vacuum ejector 91 and the second vacuum ejector 92 so that the negative pressure during suction by the first vacuum ejector 91 and the second vacuum ejector 92 is higher than the negative pressure during suction by the suction pump 62. However, the negative pressure during suction by the first vacuum ejector 91 and the second vacuum ejector 92 may be equal to or lower than the negative pressure during suction by the suction pump 62.

[0083] At least one of the first vacuum ejector 91 and the second vacuum ejector 92 corresponds to the cleaning and suction means. Either the first vacuum ejector 91 or the second vacuum ejector 92 corresponds to the first cleaning and suction means, and the other of the first vacuum ejector 91 and the second vacuum ejector 92 corresponds to the second cleaning and suction means.

[0084] The cap 93 is a member that tightly contacts the nozzle forming surface 32 and seals the nozzle forming surface 32 where the nozzles 33 are exposed. The cap 93 is preferably made of a flexibly deformable member such as rubber. The cap 93 may also be configured to form a small space (internal space) between itself and the nozzle forming surface 32, allowing paint droplets to be discharged into the internal space. In this case, it is preferable that the peripheral wall that forms the internal space of the cap 93 does not directly contact the portion of the nozzle forming surface 32 where the nozzles 33 are formed. The cap 93 is also preferably connected to a discharge pipe that allows paint droplets to be discharged.

[0085] The cap moving mechanism 94 is a mechanism for moving the cap 93 to seal or unseal the nozzle forming surface 32. The cap moving mechanism 94 may be a unique mechanism that includes a drive source such as a motor or actuator and a transmission mechanism such as a cam or gear that transmits the drive force from the drive source. However, the cap moving mechanism 94 may also be a robot arm R1 that can move the paint head 31 (paint head unit 30) relative to the cap 93.

[0086] (1-5. Regarding the control unit 100) Next, a description will be given of the schematic configuration of the control unit 100 for controlling the operation of the cleaning system 1 of the painting robot 10. Fig. 8 is a diagram showing the schematic control configuration centered on the control unit 100 of the cleaning system 1 of the painting robot 10. As shown in Fig. 8, the control unit 100 has a main control unit 110, a robot arm control unit 120, a head control unit 130, a paint supply control unit 140, and a cleaning control unit 150. At least one of the control unit 100, the main control unit 110, and the cleaning control unit 150 corresponds to the control means.

[0087] Of the above control configurations, the main control unit 110 sends predetermined control signals to the above-mentioned robot arm control unit 120, head control unit 130 and paint supply control unit 140 as necessary so that, during painting, the motors of the robot arm R1, the operating units of the paint supply / cleaning mechanism 50 and the piezoelectric substrate 35 work together to paint the object to be painted.

[0088] When cleaning is performed, the main control unit 110 sends predetermined control signals to the above-mentioned robot arm control unit 120, head control unit 130, paint supply control unit 140, and cleaning control unit 150 as necessary so that the motors of the robot arm R1, the operating units of the paint supply / cleaning mechanism 50, and the piezoelectric substrate 35 work together to paint the object to be painted.

[0089] The robot arm control unit 120 is a part that controls the driving of each motor of the robot arm R1 described above.

[0090] The head control unit 130 is a part that controls the operation of the piezoelectric substrate 35 in the paint head unit 30 based on image processing by an image processing device (not shown). In addition, the head control unit 130 may also control the operation of the piezoelectric substrate 35 when cleaning the interior of the paint head 31, as necessary.

[0091] The paint supply control unit 140 is a part that controls the supply of paint to the painting head 31, and specifically controls the operation of each operating part in the paint supply / cleaning mechanism 50, such as the supply pump 61, suction pump 62, first to fourth three-way valves 71 to 74, and first to sixth switching valves 81 to 86.

[0092] The cleaning control unit 150 is a part that controls the operation of related operating parts when cleaning the internal flow path 36 in the coating head 31 with a cleaning fluid (cleaning liquid or air) and each component in the paint circulation path 51. Specifically, the cleaning control unit 150 controls the operation of each operating part in the paint supply / cleaning mechanism 50, such as the supply pump 61, suction pump 62, delivery pump 64, compressor 66, cleaning switching valve 67, first to fourth three-way valves 71 to 74, first to sixth switching valves 81 to 86, first vacuum ejector 91, second vacuum ejector 92, and cap moving mechanism 94.

[0093] (2. Regarding cleaning control) Next, the control for cleaning the internal flow passage 36 in the paint head 31 will be described in detail. (2-1. Forward washing) First, forward flushing will be described. Figure 9 is a diagram showing a cleaning chart for cleaning the internal flow path 36 inside the paint head 31. In this forward flushing, as in normal painting, a cleaning fluid such as cleaning liquid or air is supplied from the paint supply path 52 toward the paint head 31. In this case, based on a command from the main control unit 110, the cleaning control unit 150 switches the cleaning switching valve 67 so as to open the valve unit 67b and close the valve unit 67a. The cleaning control unit 150 also operates the second three-way valve 72 to block the flow of cleaning fluid toward the bypass flow path 54, and further operates the third three-way valve 73 to block the supply of cleaning fluid from the bypass flow path 54.

[0094] The cleaning control unit 150 also activates the compressor 66 to prepare for supplying cleaning air to the valve unit 67c. Separately from the above, the cleaning control unit 150 also activates the cap moving mechanism 94 to bring the cap 93 into close contact with the nozzle forming surface 32. This seals the nozzle forming surface 32 (nozzles 33) from the outside.

[0095] Thereafter, the cleaning control unit 150 switches the fourth switching valve 84 so as to open the valves 84b and 84c while closing the other valves 84a, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the fifth switching valve 85 so as to open the valves 85a and 85e while closing the other valves 85b, 85c, 85d, and 85f.

[0096] Then, cleaning air flows through valves 67b, 67c and valves 84b, 84c for a predetermined time (e.g., 0.5 seconds) (air supply ON in FIG. 9(a)). After that, either valve 84b or valve 84c is shut off to shut off the air supply (air supply OFF in FIG. 9(a)). After this, it is preferable to open valve 84e to release the air and adjust the pressure (release ON in FIG. 9(a)). At this time, the air pressure is preferably 0.3 to 0.4 bar. However, a pressure outside this range may also be used. In particular, when using a coating head 31 with high pressure resistance, a pressure range higher than the above is preferable.

[0097] Next, the cleaning control unit 150 activates the delivery pump 64 to prepare for supply of cleaning liquid. After this, the cleaning control unit 150 opens the valves 84b and 84c while closing the other valves 84a, 84d, 84e, and 84f, and further switches the cleaning switching valve 67 so that the valve 67a is opened while the valve 67b is closed.

[0098] The cleaning liquid then flows through valves 67a, 67c and valves 84b, 84c for a predetermined time (e.g., 15 seconds) (cleaning liquid supply ON in FIG. 9(a)). After that, either valve 84b or valve 84c is closed to shut off the supply of cleaning liquid (cleaning liquid supply OFF in FIG. 9(a)). In this way, the cleaning liquid is supplied to the internal flow path 36 of the coating head 31 via the paint supply path 52. At this time, the pressure of the cleaning liquid is preferably 0.3 to 0.4 bar. However, a pressure outside this range may also be used. In particular, when using a coating head 31 with high pressure resistance, a pressure higher than the above range is preferable.

[0099] Then, the air or cleaning liquid that has cleaned the internal flow path 36 is discharged via the return flow path 53 and the valve units 85a and 85e into the drain tank 65. In this discharge, the cleaning control unit 150 operates the second vacuum ejector 92 to discharge the cleaning liquid or air after cleaning into the drain tank 65 by negative pressure. This makes it possible to increase the amount of cleaning liquid or air drawn into the internal flow path 36.

[0100] In this way, air and cleaning liquid at a predetermined pressure are alternately supplied to the internal flow path 36 at the predetermined pressure via the paint supply path 52. This performs forward cleaning of the internal flow path 36. At this time, since the nozzle forming surface 32 (nozzle 33) is sealed by the cap 93, the internal flow path 36 can be pressurized, and cleaning can be performed in this pressurized state.

[0101] In addition, by operating the second vacuum ejector 92, it is possible to improve the discharge performance of the used cleaning fluid, even if the return flow path 53 or the paint supply path 52 is long, compared to when the cleaning fluid is discharged by operating only the delivery pump 64.

[0102] In particular, when the cleaned cleaning fluid is discharged via the valve portion 85e of the fifth switching valve 85, it does not go through the suction pump 62. Therefore, in a comparative example in which the second vacuum ejector 92 is not used, the only driving part for discharging the cleaned cleaning fluid is the delivery pump 64, which tends to reduce the discharge performance of the cleaned fluid.

[0103] However, as described above, by providing the second vacuum ejector 92 and discharging the used cleaning fluid by operating the second vacuum ejector 92 in addition to operating the delivery pump 64, it is possible to improve the discharge performance of the cleaning fluid after cleaning compared to when only the delivery pump 64 is operated. That is, in forward cleaning, even if the return flow path 53 and the paint supply path 52 are long, it is possible to suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0104] If the forward cleaning of the internal flow path 36 with air and cleaning liquid as described above is considered to be one cycle, it is preferable to repeat this cycle of cleaning two or more times.

[0105] (2-2. Reverse cleaning) Next, reverse flushing will be described. In reverse flushing, a cleaning fluid such as a cleaning liquid or air is supplied to the coating head 31 in the opposite direction to the forward flushing described above. In this case, based on a command from the main control unit 110, the cleaning control unit 150 switches the cleaning switching valve 67 so that the valve unit 67b is opened and the valve unit 67a is closed. The cleaning control unit 150 also operates the second three-way valve 72 to block the flow of cleaning fluid toward the bypass flow path 54, and further operates the third three-way valve 73 to block the supply of cleaning fluid from the bypass flow path 54.

[0106] The cleaning control unit 150 also activates the compressor 66 to prepare for supplying cleaning air to the valve unit 67c. Separately from the above, the cleaning control unit 150 also activates the cap moving mechanism 94 to bring the cap 93 into close contact with the nozzle forming surface 32. This seals the nozzle forming surface 32 (nozzles 33) from the outside.

[0107] Thereafter, the cleaning control unit 150 switches the fifth switching valve 85 so as to open the valves 85a and 85c while closing the other valves 85b, 85d, 85e, and 85f. Furthermore, the cleaning control unit 150 switches the fourth switching valve 84 so as to open the valves 84b and 84e while closing the other valves 84a, 84c, 84d, and 84f.

[0108] Then, cleaning air flows through valves 67b, 67c and valves 85a, 85c for a predetermined time (e.g., 0.5 seconds) (air supply ON in FIG. 9(b)). After that, either valve 85a or valve 85c is shut off to shut off the air supply (air supply OFF in FIG. 9(b)). After this, valve 85e is preferably opened to release the air and adjust the pressure (release ON in FIG. 9(b)).

[0109] Next, the cleaning control unit 150 activates the delivery pump 64 to prepare for supply of cleaning liquid. After this, the cleaning control unit 150 switches the cleaning switching valve 67 so that the valve 67a is opened and the valve 67b is closed, while the valves 85a and 85c are opened and the other valves 85b, 85d, 85e, and 85f are closed.

[0110] Then, the cleaning liquid flows through the valves 67a, 67c and the valves 85a, 85c for a predetermined time (e.g., 15 seconds) (cleaning liquid supply ON in FIG. 9(b)). After that, either the valve 85a or the valve 85c is closed to cut off the supply of cleaning liquid (cleaning liquid supply OFF in FIG. 9(b)). In this way, the cleaning liquid is supplied to the internal flow path 36 of the coating head 31 via the paint supply path 52.

[0111] Then, the air or cleaning liquid that has cleaned the internal flow path 36 is discharged via the paint supply path 52 and the valves 84b and 84e into the drain tank 65. During this discharge, the cleaning control unit 150 activates the first vacuum ejector 91 to use negative pressure to discharge the cleaning liquid or air after cleaning into the drain tank 65. This makes it possible to increase the amount of cleaning liquid or air drawn into the internal flow path 36.

[0112] In this way, air and cleaning liquid at a predetermined pressure are alternately supplied to the internal flow path 36 through the return flow path 53 at a predetermined pressure, thereby performing reverse cleaning of the internal flow path 36. At this time, since the nozzle forming surface 32 (nozzles 33) is sealed with the cap 93, the internal flow path 36 can be pressurized, and cleaning can be performed in this pressurized state.

[0113] Furthermore, as described above, by discharging the cleaning fluid used in cleaning by operating the first vacuum ejector 91 in addition to operating the delivery pump 64, it is possible to improve the discharge performance of the cleaning fluid after cleaning compared to when only the delivery pump 64 is operated. That is, in reverse cleaning, even if the return flow path 53 and the paint supply path 52 are long, it is possible to suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0114] If the above-described reverse cleaning of the internal flow path 36 with air and cleaning liquid is considered to be one cycle, it is preferable to repeat this cycle of cleaning two or more times.

[0115] (3. Modifications) (3-1. Cleaning when there is one vacuum ejector) In the above-described embodiment, two vacuum ejectors, a first vacuum ejector 91 and a second vacuum ejector 92, are used. However, it is also possible to perform forward cleaning and reverse cleaning using one vacuum ejector. In this case, cleaning can be performed for each section that is the target of cleaning. This case will be described below with reference to FIG. 10. In FIG. 10, one vacuum ejector will be described as a vacuum ejector 95. In this case, the vacuum ejector 95 corresponds to the cleaning suction means and also corresponds to either the first cleaning suction means or the second cleaning suction means. However, the first to sixth switching valves 81 to 86 may be included in the cleaning suction means, or either the first cleaning suction means or the second cleaning suction means.

[0116] (3-1a. Forward washing) First, forward cleaning will be described. In this case, the cleaning target is the internal flow path 36 of the paint head 31, the paint supply path 52 leading to the internal flow path 36, and the first section of the return flow path 53 through which cleaning fluid discharged from the internal flow path 36 flows. First, the cleaning control unit 150 controls the operation of the first to third three-way valves 71 to 73, the compressor 66, the cleaning switching valve 67, and the cap moving mechanism 94, as in the above-described embodiment. Then, the fourth switching valve 84 is switched to open the valves 84b and 84c while closing the other valves 84a, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the fifth switching valve 85 to open the valves 85a and 85e while closing the other valves 85b, 85c, 85d, and 85f.

[0117] The details of the subsequent cleaning are the same as those in "2-1. Forward cleaning" above, so a detailed explanation will be omitted.

[0118] Then, the air or cleaning liquid that has cleaned the internal flow path 36 is discharged via the return flow path 53 and the valve units 85a and 85e into the drain tank 65. In this discharge, the cleaning control unit 150 operates the vacuum ejector 95 to use negative pressure to discharge the cleaning liquid or air after cleaning into the drain tank 65. This makes it possible to increase the amount of cleaning liquid or air drawn into the internal flow path 36 compared to when the suction pump 62 is operated.

[0119] Here, the cleaning control unit 150 may, for example, operate the cap moving mechanism 94 to adjust the state of adhesion of the cap 93 to the nozzle forming surface 32, and further control the operation of the vacuum ejector 95 to change the negative pressure caused by the operation of the vacuum ejector 95, thereby varying the ratio between the amount of cleaning fluid flowing through the internal flow path 36 that is ejected from the nozzle 33 and the amount that passes through the internal flow path 36 without being ejected from the nozzle 33.

[0120] That is, when the cap 93 is not completely in contact with the nozzle forming surface 32, a predetermined amount of cleaning fluid leaks out from the nozzle 33. If the negative pressure caused by the operation of the vacuum ejector 95 changes in this leaking state, the amount of cleaning fluid leaking out from the nozzle 33 can be adjusted to an appropriate ratio. Therefore, even in cases where it would be better to directly expel foreign matter from the nozzle 33 using cleaning fluid, this can be addressed by adjusting the amount of cleaning fluid ejected from the nozzle 33.

[0121] In this manner, air and cleaning liquid at a predetermined pressure are alternately supplied to the internal flow path 36 at the predetermined pressure via the paint supply path 52. This performs forward cleaning of the internal flow path 36. At this time, the nozzle forming surface 32 (nozzle 33) is sealed with the cap 93, so the internal flow path 36 can be pressurized, and cleaning can be performed in this pressurized state.

[0122] In addition, by operating the vacuum ejector 95, it is possible to improve the discharge performance of the used cleaning fluid compared to when the cleaning fluid is discharged by operating only the delivery pump 64, even if the return flow path 53 or the paint supply path 52 is long.

[0123] In particular, when the cleaned cleaning fluid is discharged via the valve portion 85e of the fifth switching valve 85, it does not go through the suction pump 62. Therefore, in a configuration that does not use the vacuum ejector 95 as a comparative example, the only driving part for discharging the cleaned cleaning fluid is the delivery pump 64, which tends to reduce the discharge performance of the cleaned fluid.

[0124] However, as described above, by providing the vacuum ejector 95 and discharging the used cleaning fluid by operating the vacuum ejector 95 in addition to operating the delivery pump 64, it is possible to improve the discharge performance of the cleaning fluid after cleaning compared to when only the delivery pump 64 is operated. That is, in forward cleaning, even if the return flow path 53 and the paint supply path 52 are long, it is possible to suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0125] If the forward cleaning of the internal flow path 36 with air and cleaning liquid as described above is considered to be one cycle, it is preferable to repeat this cycle of cleaning two or more times.

[0126] Furthermore, when the cleaning target is the second section including the degassing module 59 in addition to the first section in which the main cleaning target is the internal flow path 36 as described above, the cleaning control unit 150 switches the third switching valve 83 to open the valves 83b and 83c while closing the other valves 83a and 83d. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the fifth switching valve 85 to open the valves 85a and 85e while closing the other valves 85b, 85c, 85d, and 85f.

[0127] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0128] Furthermore, when the cleaning target is the third section, which includes the removal filter 58 in addition to the second section, whose main cleaning targets are the internal flow path 36 and the degassing module 59, as described above, the cleaning control unit 150 switches the second switching valve 82 to open the valves 82b and 82c while closing the other valves 82a and 82d. The cleaning control unit 150 also switches the third switching valve 83 to open the valves 83a and 83b while closing the other valves 83c and 83d. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. The cleaning control unit 150 also switches the fifth switching valve 85 to open the valves 85a and 85e while closing the other valves 85b, 85c, 85d, and 85f.

[0129] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0130] Furthermore, when the cleaning target is the fourth section, which includes the paint supply path 52 between the first switching valve 81 and the second switching valve 82 in addition to the third section, whose main cleaning targets are the internal flow path 36, the degassing module 59, and the removal filter 58, as described above, the cleaning control unit 150 switches the first switching valve 81 to open the valves 81b and 81c while closing the other valves 81a and 81d. The cleaning control unit 150 also switches the second switching valve 82 to open the valves 82a and 82b while closing the other valves 82c and 82d. The cleaning control unit 150 also switches the third switching valve 83 to open the valves 83a and 83b while closing the other valves 83c and 83d. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the fifth switching valve 85 so that the valve units 85a and 85e are opened, while the other valve units 85b, 85c, 85d, and 85f are closed.

[0131] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0132] (3-1b. Reverse cleaning) Next, reverse cleaning will be described. In reverse cleaning, a cleaning fluid such as cleaning liquid or air is supplied to the paint head 31 in the opposite direction to the forward cleaning described above. In this case, the cleaning target is the internal flow path 36 of the paint head 31, the paint supply path 52 leading to the internal flow path 36, and the first section of the return flow path 53 through which the cleaning fluid discharged from the internal flow path 36 flows. First, the cleaning control unit 150 controls the operation of the first to third three-way valves 71 to 73, the compressor 66, the cleaning switching valve 67, and the cap moving mechanism 94, as in the above-described embodiment. Then, the cleaning control unit 150 switches the fifth switching valve 85 so as to open the valves 85a and 85c while closing the other valves 85b, 85d, 85e, and 85f. Furthermore, the cleaning control unit 150 switches the fourth switching valve 84 so as to open the valves 84b and 84e while closing the other valves 84a, 84c, 84d, and 84f.

[0133] The details of the subsequent cleaning are the same as those in "2-2. Reverse cleaning" above, so a detailed explanation will be omitted.

[0134] Then, the air or cleaning liquid that has cleaned the internal flow path 36 is discharged via the paint supply path 52 and the valves 84b and 84e into the drain tank 65. In this discharge, the cleaning control unit 150 operates the vacuum ejector 95 to use negative pressure to discharge the cleaning liquid or air after cleaning into the drain tank 65. This makes it possible to increase the amount of cleaning liquid or air drawn into the internal flow path 36.

[0135] In this way, air at a predetermined pressure and cleaning liquid are alternately supplied to the internal flow path 36 at a predetermined pressure via the return flow path 53. This performs reverse cleaning of the internal flow path 36. At this time, since the nozzle forming surface 32 (nozzles 33) is sealed with the cap 93, the internal flow path 36 can be pressurized, and cleaning can be performed in this pressurized state.

[0136] Furthermore, as described above, by providing the vacuum ejector 95 and discharging the used cleaning fluid by operating the vacuum ejector 95 in addition to operating the delivery pump 64, it is possible to improve the discharge performance of the cleaning fluid after cleaning compared to operating only the delivery pump 64. That is, in reverse cleaning, even if the return flow path 53 and the paint supply path 52 are long, it is possible to suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0137] If the above-described reverse cleaning of the internal flow path 36 with air and cleaning liquid is considered to be one cycle, it is preferable to repeat this cycle of cleaning two or more times.

[0138] When performing reverse cleaning in a second section including the degassing module 59 in addition to the first section in which the main cleaning target is the internal flow path 36, the cleaning control unit 150 switches the fifth switching valve 85 to open the valves 85a and 85c while closing the other valves 85b, 85d, 85e, and 85f, as described above. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the third switching valve 83 to open the valves 83b and 83d while closing the other valves 83a and 83c.

[0139] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0140] When performing reverse cleaning in a third section including the removal filter 58 in addition to the second section, whose main cleaning targets are the internal flow path 36 and the degassing module 59, the cleaning control unit 150 switches the fifth switching valve 85 to open the valves 85a and 85c while closing the other valves 85b, 85d, 85e, and 85f, as described above. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. The cleaning control unit 150 also switches the third switching valve 83 to open the valves 83a and 83b while closing the other valves 83c and 83d. The cleaning control unit 150 also switches the second switching valve 82 to open the valves 82b and 82d while closing the other valves 82a and 82c.

[0141] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0142] When performing reverse cleaning in the fourth section, which includes the paint supply path 52 between the first and second switching valves 81 and 82 in addition to the third section, whose main cleaning targets are the internal flow path 36, the degassing module 59, and the removal filter 58, the cleaning control unit 150 switches the fifth switching valve 85 to open the valves 85a and 85c while closing the other valves 85b, 85d, 85e, and 85f, as described above. The cleaning control unit 150 also switches the fourth switching valve 84 to open the valves 84a and 84b while closing the other valves 84c, 84d, 84e, and 84f. The cleaning control unit 150 also switches the third switching valve 83 to open the valves 83a and 83b while closing the other valves 83c and 83d. The cleaning control unit 150 also switches the second switching valve 82 so that the valves 82a and 82b are opened while the other valves 82c and 82d are closed. The cleaning control unit 150 also switches the first switching valve 81 so that the valves 81a and 81b are opened while the other valves 81c and 81d are closed. Furthermore, the cleaning control unit 150 switches the first three-way valve 71 so that the cleaning fluid does not flow toward the paint tank 57 side but flows toward the drainage tank 65 side.

[0143] The details of the subsequent cleaning are the same as those in the first section, and therefore will not be described in detail.

[0144] (3-2. Discharge of cleaning fluid after cleaning from valves other than the fifth switching valve 85) In the forward cleaning described above, the cleaning fluid after cleaning is discharged from the valve portion 85e of the fifth switching valve 85 toward the drain tank 65. However, the cleaning fluid after cleaning may be discharged toward the drain tank 65 after passing through at least the sixth switching valve 86.

[0145] In this case, the cleaning control unit 150 switches the fifth switching valve 85 so as to open the valves 85a and 85b and close the other valves 85c, 85d, and 85f, for example. The cleaning control unit 150 also switches the sixth switching valve 86 so as to open the valves 86a and 86b and close the other valves 86c and 86d. Furthermore, the cleaning control unit 150 switches the fourth three-way valve 74 so that the cleaning fluid does not flow toward the paint tank 57, but flows toward the drainage tank 65.

[0146] In this case, cleaning can be performed by flowing the cleaning fluid also in the return flow path 53 between the fifth switching valve 85 and the sixth switching valve 86. Furthermore, since the cleaning fluid passes through the suction pump 62, by operating the suction pump 62 in addition to the delivery pump 64 (or the vacuum ejector 95), the cleaning fluid after cleaning can be more effectively discharged toward the drain tank 65, and it is possible to further suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0147] As another example of flowing through at least the sixth switching valve 86, the cleaning control unit 150 switches the fifth switching valve 85, for example, to open the valves 85a and 85b and close the other valves 85c, 85d, 85e, and 85f. The cleaning control unit 150 also switches the sixth switching valve 86 to open the valves 86a and 86d and close the other valves 86b and 86c. The cleaning control unit 150 also switches the first switching valve 81 to open the valves 81a and 81d and close the other valves 81b and 81c. Furthermore, the cleaning control unit 150 switches the first three-way valve 71 so that the cleaning fluid does not flow toward the paint tank 57 but flows toward the drainage tank 65.

[0148] In this case, cleaning can be performed by flowing the cleaning fluid also in the return flow path 53 between the fifth switching valve 85 and the sixth switching valve 86. Furthermore, cleaning can be performed by flowing the cleaning fluid also in the second bypass flow path 56.

[0149] (3-3. Supply of cleaning fluid from a source other than the fifth switching valve 85) In the above-described reverse cleaning, the cleaning fluid is supplied from the valve portion 85c of the fifth switching valve 85. However, the cleaning fluid may be supplied from the valve portion 85c of the sixth switching valve 86.

[0150] In this case, the cleaning control unit 150 switches the sixth switching valve 86 so as to open the valves 86a and 86c and close the other valves 86b and 86d. The cleaning control unit 150 also switches the fifth switching valve 85 so as to open the valves 85a and 85b and close the other valves 85c, 85d, 85e, and 85f.

[0151] In this case, it is also possible to cause the cleaning fluid to flow in the return flow path 53 between the fifth switching valve 85 and the sixth switching valve 86 to perform cleaning.

[0152] (3-4. Supply of cleaning fluid via the first switching valve 81, the second bypass flow path 56, and the sixth switching valve 86) In addition, in reverse cleaning, the cleaning control unit 150 may supply a cleaning fluid such as cleaning liquid or air from the first switching valve 81, and further supply the cleaning fluid from the return flow path 53 to the internal flow path 36 via the second bypass flow path 56 and the sixth switching valve 86.

[0153] At this time, the first selector valve 81 is switched so that the valve portions 81c and 81d are opened while the other valve portions 81a and 81b are closed. The sixth selector valve 86 is also switched so that the valve portions 86a and 86d of the sixth selector valve 86 are opened while the other valve portions 86b and 86c are closed. The fifth selector valve 85 is also switched so that the valve portions 85a and 85b of the fifth selector valve 85 are opened while the other valve portions 85c, 85d, 85e, and 85f are closed. This allows the cleaning fluid to be supplied from the return flow path 53 to the internal flow path 36 via the first selector valve 81, the second bypass flow path 56, the sixth selector valve 86, and the fifth selector valve 85.

[0154] Note that, to discharge the cleaning fluid on the paint supply passage 52 side, the second to fourth selector valves 82 to 84 are switched so that the cleaning fluid is discharged from at least one of the second to fourth selector valves 82 to 84. Specifically, when switching the second selector valve 82, operation is controlled to open the valve portions 82b and 82d while closing the other valve portions 82a and 82c. When switching the third selector valve 83, operation is controlled to open the valve portions 83b and 83d while closing the other valve portions 83a and 83c. When switching the fourth selector valve 84, operation is controlled to open the valve portions 84b and 84e while closing the other valve portions 84a, 84c, 84d, and 84f.

[0155] In this way, in reverse cleaning, when cleaning fluid such as cleaning liquid or air is supplied from the first switching valve 81, and then the cleaning fluid is supplied from the return flow path 53 side to the internal flow path 36 via the second bypass flow path 56 and the sixth switching valve 86, it is possible to clean the return flow path 53 as well as the paint head 31.

[0156] (3-5. Supply of cleaning fluid via the first switching valve 81, the paint tank 57, and the sixth switching valve 86) In addition, in reverse cleaning, the cleaning control unit 150 may supply cleaning fluid such as cleaning liquid or air from the first switching valve 81, and further supply the cleaning fluid from the return flow path 53 to the internal flow path 36 via the paint tank 57 and the sixth switching valve 86.

[0157] At this time, the first switching valve 81 is switched so that the valve portions 81a and 81c are opened while the other valve portions 81b and 81d are closed. Also, the first three-way valve 71 is switched so that the cleaning fluid does not flow to the drainage tank 65 side but flows toward the paint tank 57 side. Also, the fourth three-way valve 74 is switched so that the cleaning fluid does not flow to the drainage tank 65 side but flows toward the sixth switching valve 86 side.

[0158] Furthermore, the sixth selector valve 86 is switched so that the valve portions 86a and 86d of the sixth selector valve 86 are opened while the other valve portions 86b and 86c are closed. Furthermore, the fifth selector valve 85 is switched so that the valve portions 85a and 85b of the fifth selector valve 85 are opened while the other valve portions 85c, 85d, 85e, and 85f are closed. As a result, the cleaning fluid is supplied from the return flow path 53 to the internal flow path 36 via the first selector valve 81, the second bypass flow path 56, the sixth selector valve 86, and the fifth selector valve 85.

[0159] The discharge of cleaning fluid on the paint supply path 52 side is the same as the supply of cleaning fluid via the first switching valve 81, the second bypass path 56 and the sixth switching valve 86 described above, so its explanation will be omitted.

[0160] In such reverse cleaning, it is possible to clean the return flow path 53 as well as the paint head 31. It is also possible to clean the paint tank 57.

[0161] (3-6. Pressure fluctuation due to cap 93) In the above-described embodiment or modification, when at least one of the forward cleaning and reverse cleaning operations is performed, the cleaning control unit 150 may control the cap moving mechanism 94 to vary the sealing pressure of the nozzle surface 32 and the internal flow path 36 by the cap 93. Also, the pressure of the nozzle surface 32 and the internal flow path 36 may be varied by releasing the sealing state of the nozzle surface 32 by the cap 93 and then sealing it again.

[0162] By generating such pressure fluctuations, it becomes possible to improve the discharge of foreign matter in the internal flow path 36.

[0163] (3-7. Other Modifications) In the above embodiment, the delivery pump 64 corresponds to the pressurizing means, but a separate member may serve as the pressurizing means instead of the delivery pump 64. For example, when the cleaning liquid or air is supplied from the upstream side of the supply pump 61, the supply pump 61 may serve as the pressurizing means.

[0164] In the above-described embodiment, the first vacuum ejector 91 and the second vacuum ejector 92 correspond to the cleaning and suction means, but a separate member may instead serve as the suction means. For example, when cleaning liquid or air is supplied from the upstream side of the return flow path 53 relative to the suction pump 62, the suction pump 62 may also serve as the pressurizing means. Furthermore, as the cleaning and suction means, instead of at least one of the first vacuum ejector 91 and the second vacuum ejector 92, a pump similar to the suction pump may be connected to the valve unit 84e or 85e.

[0165] (4. Supplementary Note) The contents described in the above-described embodiment can be understood, for example, as follows. [1] That is, A cleaning system 1 for a painting robot 10 that paints a painting part of a vehicle, a paint head unit 30 including an inkjet type paint head 31 having a plurality of nozzles 33 arranged therein for ejecting paint droplets; a robot arm R1 having a painting head unit 30 attached to its tip and moving the painting head unit 30 to a desired position; a cap 93 that seals at least a portion of the nozzle forming surface 32 where the nozzles 33 are exposed; a cap moving mechanism 94 that moves the cap 93 relative to the nozzle forming surface 32 to seal the nozzle forming surface 32; a return flow path 53 connected to the paint discharge side of the painting head 31 and adapted to collect paint or cleaning fluid toward a paint tank 57 separate from at least the robot arm R1; a suction means (suction pump 62) provided in the middle of the return flow path 53 for sucking in at least paint that has not been discharged from the nozzle 33 during coating; a pressurizing means (delivery pump 64) for pressurizing the cleaning fluid supplied to the coating head 31 in one of the paint supply path 52 and the return path 53; a cleaning suction means (a first vacuum ejector 91, a second vacuum ejector 92, a vacuum ejector 95) for sucking cleaning fluid discharged from the coating head 31 in the other of the paint supply path 52 and the return path 53; a control means (main control unit 110, cleaning control unit 150) for controlling the operation of the pressurizing means (delivery pump 64) and the cleaning and suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95); Equipped with When cleaning using a cleaning fluid, the control means (main control unit 110, cleaning control unit 150) operates the cap moving mechanism 94 to seal the nozzle forming surface 32 with the cap 93, and then operates the pressurizing means (delivery pump 64) and the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95), thereby increasing the discharge speed of the cleaning fluid compared to when only the pressurizing means (delivery pump 64) is operated.

[0166] In this way, in the inkjet type paint head 31 using the paint robot 10, by operating the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) in addition to the pressurizing means (delivery pump 64), the discharge performance of the cleaning fluid can be improved compared to when only the pressurizing means (delivery pump 64) is operated. Therefore, even if the return flow path 53 and the paint supply path 52 are long, it is possible to suppress a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time.

[0167] In particular, for example, when the cleaning fluid is supplied via the valve portions 84b and 84c of the fourth selector valve 84 and the used cleaning fluid is discharged via the valve portions 85a and 85e of the fifth selector valve 85, the return flow path 53 does not pass through the suction pump 62. Therefore, the suction force of the suction pump 62 cannot be utilized. Therefore, the discharge of the cleaning fluid to the drain tank 65 depends on the delivery pressure of the cleaning fluid from the delivery pump 64. This leads to a decrease in the cleaning performance of the paint circulation path 51 and an increase in the cleaning time, especially when the return flow path 53 is long.

[0168] However, as described above, by operating the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95), it is possible to suppress a decrease in the cleaning ability of the paint circulation path 51 and an increase in the cleaning time, especially even in specifications where the return flow path 53 is long.

[0169] Furthermore, by sealing the nozzle forming surface 32 with the cap 93, it is possible to prevent the cleaning fluid from leaking out from the nozzles 33, and therefore cleaning can be performed with a predetermined pressure applied to the internal flow path 36. This makes it possible to increase the supply pressure of the cleaning fluid in the internal flow path 36, making it possible to effectively clean the internal flow path 36 and the nozzles 33 with the cleaning fluid, and making it possible to eliminate clogging of the internal flow path 36 and the nozzles 33.

[0170] [2] In addition to the above-mentioned embodiment, in addition to the contents described in [1] above, The paint head 31 has a plurality of internal passages 36 that supply paint or cleaning fluid to the nozzles 33; The control means (main control unit 110, cleaning control unit 150) operates the cap moving mechanism 94 to adjust the state of contact of the cap 93 with the nozzle forming surface 32, It is preferable to control the operation of the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) and change the negative pressure caused by the operation of the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95), thereby varying the ratio of the amount of cleaning fluid flowing through the internal flow path 36 that is discharged from the nozzle 33 to the amount that passes through the internal flow path 36 without being discharged from the nozzle 33.

[0171] In this way, by operating the cap moving mechanism 94 to adjust the state of contact of the cap 93 with the nozzle forming surface 32, it is possible to create a state in which a predetermined amount of cleaning fluid leaks from the nozzle 33. If the negative pressure caused by the operation of the cleaning suction means (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) changes in such a state in which cleaning fluid is leaking, the amount of cleaning fluid leaking from the nozzle 33 can be adjusted to an appropriate ratio. Therefore, even in cases where it would be better to directly discharge foreign matter from the nozzle 33 using cleaning fluid, this can be addressed by adjusting the amount of cleaning fluid ejected from the nozzle 33.

[0172] [3] In addition to the above-mentioned embodiments [1] and [2], or a combination thereof, A first cleaning suction means (first vacuum ejector 91) corresponding to the cleaning suction means is connected to the paint supply path 52, A second cleaning suction means (second vacuum ejector 92) corresponding to the cleaning suction means is connected to the return flow path 53, The control means (main control unit 110, cleaning control unit 150) When performing forward cleaning in which the cleaning fluid flows from the paint supply passage 52 to the return passage 53, the second cleaning suction means (second vacuum ejector 92) is operated to suck the cleaning fluid from the return passage 53, When performing reverse cleaning in which the cleaning fluid flows from the return flow path 53 to the paint supply path 52, it is preferable to operate the first cleaning suction means (first vacuum ejector 91) so as to suck the cleaning fluid from the paint supply path 52.

[0173] In this way, the control means (main control unit 110, cleaning control unit 150) can operate the first cleaning suction means (first vacuum ejector 91) to effectively perform forward cleaning. Furthermore, the control means (main control unit 110, cleaning control unit 150) can operate the second cleaning suction means (second vacuum ejector 92) to effectively perform reverse cleaning. By performing forward cleaning and reverse cleaning in this way, it is possible to improve the discharge of foreign matter present in the paint supply path 52, the return path 53, the components in those paths (the removal filter 58 and the degassing module 59), the internal path 36 of the paint head 31, the nozzle 33, etc. Therefore, it is possible to improve the cleanability of each of these parts.

[0174] [4] In addition to the above-mentioned [3], in the above embodiment, The control means (main control unit 110, cleaning control unit 150) When performing at least one of the forward cleaning and reverse cleaning operations, the cap moving mechanism 94 may be operated to vary the sealing pressure of the nozzle forming surface 32 by the cap 93, or to release the sealing state of the nozzle forming surface 32 by the cap 93 and then seal it again.

[0175] In this way, by operating the cap moving mechanism 94 and varying the sealing pressure of the cap 93 on the nozzle forming surface 32, it is possible to cause cleaning fluid to leak from the nozzle 33, for example, thereby improving the discharge of foreign matter present in the internal flow path 36 and the nozzle 33 and improving cleanability. Furthermore, by releasing the sealing state of the nozzle forming surface 32 with the cap 93, the flow direction of cleaning fluid such as cleaning liquid and air in the internal flow path 36 and the nozzle 33 inside the paint head 31 is significantly changed, making it possible to improve the discharge of foreign matter present in the internal flow path 36 and the nozzle 33 and improving cleanability.

[0176] [5] In addition to the above-mentioned [3], in the above embodiment, It is preferable that the first cleaning and suction means and the second cleaning and suction means use the same vacuum ejector 95 .

[0177] In this configuration, there is no need to provide two vacuum ejectors, so the configuration can be simplified and the cost for producing the cleaning system 1 can be reduced. [Explanation of symbols]

[0178] 1...Cleaning system, 2...Nozzle forming surface, 10...Painting robot, 15...Moving device, 16...Moving table, 17...Rail, 18...Drive mechanism, 18a...Drive sprocket, 18b...Driven sprocket, 18c...Drive belt, 21...Base, 22...First pivoting arm, 23...Second pivoting arm, 24...Fixed portion, 25...Rotating portion, 26...Movable shaft portion, 27...Movable shaft portion, 28...Wrist portion, 30...Painting head unit, 31...Painting head, 32...Nozzle forming surface, 33...Nozzle, 34...Nozzle row, 34A...First nozzle row, 34B...second nozzle row, 35...piezoelectric substrate, 36...internal flow path, 37...nozzle pressurizing chamber, 50...paint supply / cleaning mechanism, 51...paint circulation path, 52...paint supply path, 53...return flow path, 54...bypass flow path, 55...external supply path, 56...second bypass flow path, 57...paint tank, 58...removal filter, 59...deaeration module, 61...supply pump, 62...suction pump, 63...cleaning tank, 64...delivery pump (corresponding to pressurizing means), 65...drainage tank, 66...compressor, 67...cleaning switching valve, 67a to 67c ...valve section, 71...first three-way valve, 72...second three-way valve, 73...third three-way valve, 74...fourth three-way valve, 81...first switching valve (corresponding to part of the cleaning and suction means), 81a to 81d...valve section, 82...second switching valve (corresponding to part of the cleaning and suction means), 82a to 82d...valve section, 83...third switching valve (corresponding to part of the cleaning and suction means), 83a to 83d...valve section, 84...fourth switching valve (corresponding to part of the cleaning and suction means), 84a to 84f...valve section, 85...fifth switching valve (corresponding to part of the cleaning and suction means), 85a to 85f...valve section, 86...sixth switching valve (corresponding to part of the cleaning and suction means), 86a to 86d... valve section, 91... first vacuum ejector (corresponding to the cleaning and suction means), 92... second vacuum ejector (corresponding to the cleaning and suction means), 93... cap, 94... cap moving mechanism, 95... vacuum ejector (corresponding to the cleaning and suction means), 100... control section (corresponding to the control means), 110... main control section (corresponding to the control means), 120... robot arm control section, 130... head control section, 140... paint supply control section, 150... cleaning control section (corresponding to the control means), R1... robot arm

Claims

1. A cleaning system for a painting robot that paints a painting portion of a vehicle, a paint head unit equipped with an inkjet type paint head having a plurality of nozzles arranged to eject paint; a robot arm having the painting head unit attached to its tip and moving the painting head unit to a desired position; a cap that seals at least a portion of the nozzle forming surface where the nozzles are exposed; a cap moving mechanism that moves the nozzle forming surface relative to the cap to realize a sealed state of the nozzle forming surface; a paint supply passage for supplying the paint or cleaning fluid toward the paint head; a return flow path connected to a paint discharge side of the paint head and configured to collect the paint or the cleaning fluid toward a paint tank separate from at least the robot arm; a pressurizing means for pressurizing the cleaning fluid supplied to the coating head through one of the paint supply passage and the return passage; a cleaning suction means for sucking the cleaning fluid discharged from the coating head through the other of the paint supply passage and the return passage; a control means for controlling the operation of the pressurizing means and the cleaning and suction means; Equipped with the control means, during cleaning using the cleaning fluid, activates the cap moving mechanism to seal the nozzle forming surface with the cap, and then activates the pressurizing means and the cleaning suction means, thereby increasing the discharge speed of the cleaning fluid compared to when only the pressurizing means is activated. A cleaning system for a painting robot.

2. 2. The painting robot cleaning system according to claim 1, the paint head has a plurality of internal flow passages that supply the paint or the cleaning fluid to the nozzle; The control means activating the cap moving mechanism to adjust the state of contact of the cap with the nozzle forming surface; by controlling the operation of the cleaning and suction means and changing the negative pressure caused by the operation of the cleaning and suction means, the ratio of the amount of the cleaning fluid flowing through the internal flow path that is discharged from the nozzle to the amount that passes through the internal flow path without being discharged from the nozzle is made variable. A cleaning system for a painting robot.

3. 2. The painting robot cleaning system according to claim 1, a first cleaning and suction means corresponding to the cleaning and suction means is connected to the paint supply path; a second cleaning and suction means corresponding to the cleaning and suction means is connected to the return flow path; The control means When performing forward cleaning in which the cleaning fluid flows from the paint supply passage to the return passage, the second cleaning suction means is operated to suck the cleaning fluid from the return passage, When performing reverse cleaning in which the cleaning fluid flows from the return flow path to the paint supply path, the first cleaning suction means is operated to suck the cleaning fluid from the paint supply path. A cleaning system for a painting robot.

4. 4. The painting robot cleaning system according to claim 3, The control means When performing at least one of the forward cleaning and the reverse cleaning, the cap moving mechanism is operated to vary the sealing pressure of the nozzle forming surface by the cap, or to release the sealing state of the nozzle forming surface by the cap and then seal it again. A cleaning system for a painting robot.

5. 4. The painting robot cleaning system according to claim 3, the first cleaning and suction means and the second cleaning and suction means use the same vacuum ejector; A cleaning system for a painting robot.

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