Painting robot cleaning system

Abstract

Provided is a cleaning system for a painting robot that can suppress a decrease in cleaning performance and an increase in cleaning time even if the return flow path from the painting head is long. The cleaning system for a painting robot has a painting head unit having an inkjet painting head; a robot arm; a cap that covers at least a portion of a nozzle formation surface; a cap moving mechanism; a paint supply path; a return flow path that recovers paint or a cleaning fluid to a paint tank that is separate from the robot arm; a pressurizing mechanism that pressurizes the cleaning fluid; a cleaning suction mechanism that suctions the cleaning fluid; and a control mechanism that controls the operation of the pressurizing mechanism and the cleaning suction mechanism. When cleaning, the control mechanism operates the cap moving mechanism and covers the nozzle formation surface with the cap, and then operates the cleaning suction mechanism in conjunction with the pressurizing mechanism.

Description

Technical Field

[0001] This invention relates to a cleaning system for painting robots. Background Technology

[0002] Among painting robots that paint vehicles, there is, for example, the technology shown in Patent Document 1. Patent Document 1 discloses a paint circulation path for an inkjet painting device, consisting of an ink tank (11), a path (12) for conveying ink from the ink tank (11) to the inkjet head (10), and a loop (13) for returning ink from the inkjet head (10) to the ink tank (11).

[0003] In this configuration, during cleaning, the ink flows from the outgoing path (12) around the inkjet head (10) to the return path (13), and the cleaning fluid flows to the inkjet head (10) using the cleaning fluid paths of other systems, namely the first cleaning fluid flow path (15) and the second cleaning fluid flow path (16). Figure 2 A). Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-030047 Summary of the Invention

[0005] Although in the configuration disclosed in Patent Document 1, the cleaning fluid can simply flow within the loop (13) during cleaning in order to clean the return flow path of the ink, the loop (13) can be extended. However, if the distance between the ink tank (11) and the inkjet head (10) is long, the loop (13) will also become longer. As a result, the return of the cleaning fluid from the inkjet head will be worse, and the overall cleaning efficiency of the coating circulation path will also be reduced.

[0006] The present invention is made based on the above, and aims to provide a cleaning system for a painting robot that can suppress the reduction of the cleanability of the paint circulation path and the increase of the cleaning time, even when the return flow path is long from the painting head.

[0007] To address the aforementioned issues, according to a first aspect of the present invention, a cleaning system for a painting robot is provided. The painting robot paints the painting areas of a vehicle. The cleaning system is characterized by comprising: a painting head unit having an inkjet-type painting head with a plurality of nozzles arranged to spray paint; a robot arm having the painting head unit mounted at its front end and moving the painting head unit to a desired position; a cap that closes at least a portion of the nozzle forming surface, wherein the nozzles are exposed on the nozzle forming surface; a cap moving mechanism that moves the nozzle forming surface relative to the cap to achieve a closed state of the nozzle forming surface; a paint supply path that supplies paint or cleaning fluid to the painting head; and a return flow path connected to the painting head. The system includes a paint discharge side connection that recovers paint or cleaning fluid at least towards a paint tank separate from the robotic arm; a pressurization mechanism that pressurizes the cleaning fluid supplied to the coating head in one of the paint supply path and the return flow path; a cleaning suction mechanism that suctions the cleaning fluid discharged from the coating head in the other of the paint supply path and the return flow path; and a control mechanism that controls the operation of the pressurization mechanism and the cleaning suction mechanism. When cleaning with the cleaning fluid is used, the control mechanism operates the cleaning suction mechanism in conjunction with the pressurization mechanism after the cap moving mechanism is activated and the nozzle forming surface is closed by the cap, thereby increasing the discharge rate of the cleaning fluid compared to the case where only the pressurization mechanism is activated. Invention Effects

[0008] According to the present invention, a cleaning system for a painting robot can be provided that, even in the case of a long return flow path from the painting head, can suppress the reduction in the cleanability of the paint circulation path and the increase in cleaning time. Attached Figure Description

[0009] Figure 1 This is a top view showing the configuration of a painting robot according to one embodiment of the present invention. Figure 2 This is observed from the upstream side of the coating production line. Figure 1 The image shown is of a painting robot. Figure 3 Side view of the vehicle body Figure 1 The image shown is of a painting robot. Figure 4 It means Figure 1 The diagram shows a schematic representation of the cleaning system of the painting robot. Figure 5 It indicates a positive observation. Figure 1 The diagram shows the state of the nozzle forming the paint spraying surface in the painting head unit of the painting robot. Figure 6 It means and Figure 3The diagram shows a top view of the nozzle forming surface configuration, which differs from other coating head units. Figure 7 It means to Figure 1 The diagram shows a rough configuration of the nozzles of the painting head of the painting robot, which supply paint. Figure 8 It means to indicate Figure 1 The diagram shows a schematic representation of the control unit and related control components of the cleaning system of the painting robot. Figure 9 It means Figure 1 The diagram shows the cleaning process in the internal flow path cleaning of the painting head of the painting robot. Figure 10 This is a diagram showing the general structure of a modified cleaning system. Explanation of reference numerals in the attached figures 1… Cleaning system, 2… Nozzle forming surface, 10… Painting robot, 15… Moving device, 16… Moving table, 17… Track, 18… Drive mechanism, 18a… Drive side sprocket, 18b… Driven side sprocket, 18c… Drive belt, 21… Base, 22… First rotating arm, 23… Second rotating arm, 24… Fixed part, 25… Rotating part, 26… Movable shaft, 27… Movable shaft, 28… Wrist, 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 pressurization chamber, 50…paint supply and 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…degassing module, 61…supply pump, 62…suction pump, 63…cleaning tank, 64…export pump (corresponding to pressurization mechanism), 65…drainage tank, 66…compressor, 67…cleaning switching valve, 67a~67c…valve section, 71…first three-way valve, 72…second three-way valve 73…3rd three-way valve, 74…4th three-way valve, 81…1st switching valve (corresponding to a part of the cleaning suction mechanism), 81a~81d…valve section, 82…2nd switching valve (corresponding to a part of the cleaning suction mechanism), 82a~82d…valve section, 83…3rd switching valve (corresponding to a part of the cleaning suction mechanism), 83a~83d…valve section, 84…4th switching valve (corresponding to a part of the cleaning suction mechanism), 84a~84f…valve section, 85…5th switching valve (corresponding to a part of the cleaning suction mechanism), 85a~85f…valve section, 86…6th switching valve Valve (corresponding to a part of the cleaning suction mechanism), 86a~86d…valve section, 91…first vacuum ejector (corresponding to the cleaning suction mechanism), 92…second vacuum ejector (corresponding to the cleaning suction mechanism), 93…cap, 94…cap moving mechanism, 95…vacuum ejector (corresponding to the cleaning suction mechanism), 100…control section (corresponding to the control mechanism), 110…main control section (corresponding to the control mechanism), 120…robot arm control section, 130…head control section, 140…paint supply control section, 150…cleaning control section (corresponding to the control mechanism), R1…robot arm Detailed Implementation

[0010] Hereinafter, a cleaning system 1 of a painting robot 10 according to one embodiment of the present invention will be described based on the accompanying drawings. Furthermore, the cleaning system 1 cleans the painting system, which performs painting by spraying paint onto the object to be painted. Therefore, the cleaning system 1 also belongs to the category of painting systems that perform painting on objects to be painted.

[0011] Additionally, in the following description, as needed, the X direction is defined as the long side direction of the nozzle forming surface 32 (coating head 31), and the X1 side is defined as... Figure 3 On the right side of the middle, the X2 side is set as Figure 3 On the left side of the nozzle forming surface 32 (coating head 31). Additionally, the Y direction is set as the short side direction (width direction) of the nozzle forming surface 32 (coating head 31), and the Y1 side is set as... Figure 3 On the upper side of the paper, the Y2 side is set as Figure 3 The bottom side of the paper.

[0012] (1. Overview of the painting robot 10) The cleaning system 1 of this embodiment cleans vehicles FR (refer to) located on the painting production line in an automobile manufacturing plant. Figure 1 as well as Figure 2 The purpose of "coating" is to form a coating film on the surface of the object to be coated, providing protection and aesthetics. Therefore, it is necessary to coat the vehicle FRs moving along the coating production line with the desired coating quality at specified intervals.

[0013] Furthermore, in the cleaning system 1 of this embodiment, not only can the above-mentioned coating be formed, but various designs and images can also be formed on objects to be painted, such as vehicle FRs. It should be noted that the objects to be painted are not limited to vehicle FRs and vehicle components, but can also be various components other than automobiles (for example, exterior components of airplanes and trains), as long as they are objects that need to be painted.

[0014] (1-1. Overall configuration of the cleaning system 1 of the painting robot 10) Figure 1 This is a top view showing the configuration of a painting robot 10 according to one embodiment of the present invention. Figure 2 This is observed from the upstream side of the coating production line. Figure 1 The image shown is of the painting robot 10. Figure 3 Viewed from the side of the vehicle Figure 1 The image shown is of a painting robot. Figure 4 It means Figure 1 A schematic diagram of the cleaning system 1 of the painting robot 10 is shown. Figures 1 to 4 As shown, the cleaning system 1 includes a painting robot 10 and a paint supply and cleaning mechanism 50.

[0015] (1-2. About the painting robot 10) like Figure 1 As shown, the painting robot 10, as an example, includes a robot arm R1, a moving device 15, and a painting head unit 30. The robot arm R1 consists of a base 21 and multiple ( Figure 1 The system consists of two arm components 22 and 23, forming a multi-axis arm. The base 21 has a fixed part 24 fixed to the movable stage 16 (described later) and a rotating part 25 rotatable relative to the fixed part 24. The fixed part 24 has a motor (not shown) inside. The rotating part 25, driven by the motor (not shown), rotates in a direction perpendicular to the ground of the painting production line. Figure 2 or Figure 3 It rotates with the z-direction or -z-direction as the center of rotation.

[0016] Hereinafter, the arm component 22 connected to the rotating part 25 among the multiple arm components 22 and 23 will be referred to as the first rotating arm 22, and the arm component 23 connected to the first rotating arm 22 will be referred to as the second rotating arm 23.

[0017] The first rotating arm 22 is connected at one end in its extending direction to a movable shaft 26 provided in the rotating part 25. A motor (not shown) is provided in the movable shaft 26 of the rotating part 25, causing the connected first rotating arm 22 to rotate in a plane orthogonal to the ground of the coating production line (e.g., when the robot arm R1 is at...). Figure 2 When in the state of rotation, it rotates on the yz plane.

[0018] In the extending direction of the first rotating arm 22, at the opposite end to the movable shaft 26 of the rotating part 25, a second rotating arm 23 is connected via a movable shaft 27. A motor (not shown) is provided in the movable shaft 27, causing the connected second rotating arm 23 to be positioned in a plane orthogonal to the ground of the painting production line (e.g., when the robot arm R1 is at...). Figure 2 When in the state of rotation, it rotates on the yz plane. Furthermore, although the illustration is omitted, the central axis of the movable shaft portion 26 of the rotating part 25 is parallel to the central axis of the movable shaft portion 27 provided on the first rotating arm 22.

[0019] At the other end of the second rotating arm 23, in the extension direction, is a wrist 28. The wrist 28 holds the coating head unit 30. Although a detailed description of the structure is omitted, the wrist 28 has multiple (three in this case) motors (not shown) with different axial directions of the drive shafts. By driving any one of these motors, the held coating head unit 30 is rotated about any one of the multiple shafts of the wrist 28 as the rotation center. Furthermore, the number of shafts is preferably two or more.

[0020] The moving device 15 is, for example, set on the floor of the painting room, so that the robot arm R1 moves along the floor of the painting room in one direction ( Figure 1 or Figure 3The robot arm R1 moves back and forth in the x-direction (or -x-direction). Furthermore, the movement direction of the robot arm R1, implemented by the moving device 15, is the coating direction (main scanning direction) of the coating head 31, described later. The moving device 15 includes a moving stage 16 for fixing the base 21 of the robot arm R1, a track 17 for guiding the movement of the moving stage 16, and a drive mechanism 18 for reciprocating the moving stage 16 along the track 17.

[0021] Track 17 is shown through a frame omitted in the illustration, for example, along the extension direction of track 17. Figure 1 It is fixed to the floor of the painting room in the x-direction or -x-direction.

[0022] The drive mechanism 18 is fixed to the floor of the painting booth via a frame (not shown). As an example, the drive mechanism 18 consists of a drive motor (not shown), a drive-side sprocket 18a, a driven-side sprocket 18b, and a drive belt 18c wound around these sprockets 18a and 18b. However, the drive mechanism 18 is not limited to this type of mechanism; it can be any configuration that enables the base 21 to move along the track 17.

[0023] (1-3. Regarding the painting head unit 30) Next, the painting head unit 30 of the painting robot 10 will be described. Figure 5 This diagram shows the state of the nozzles forming the surface 32 in the coating head 31 of the coating head unit 30 when viewed from the front. (See diagram below.) Figure 5 As shown, the coating head unit 30 has a head cover (not shown), within which various components, including the coating head 31, are built. Furthermore, the coating head 31 is provided with multiple nozzles 33 for spraying paint.

[0024] like Figure 5 As shown, on the side of the coating head 31 where the paint is sprayed (nozzle forming surface 32), there are exposed openings of multiple nozzles 33. Furthermore, in the following description, the openings of the nozzles 33 are also referred to as nozzles 33.

[0025] Furthermore, a plurality of nozzle rows 34 are provided in the nozzle forming surface 32, and in the nozzle rows 34, the nozzles 33 are connected in a direction inclined relative to the long side direction of the coating head unit 30. In this embodiment, the nozzle rows 34 include a first nozzle row 34A located on one side (Y2 side) of the main scanning direction (Y direction) and a second nozzle row 34B located on the other side (Y1 side) of the main scanning direction.

[0026] Furthermore, when spraying paint, the driving timing of each nozzle 33 is controlled so that droplets sprayed from the nozzle 33 in the second nozzle row 34B fall between droplets sprayed from adjacent nozzles 33 in the first nozzle row 34A. This increases the dot density during coating.

[0027] Furthermore, the cap 93, described later, can be configured to close the nozzle forming surface 32 from the outside by abutting against it. In this state, the vacuum jet 91, described later, is operated, thereby enabling the cleaning operation described later.

[0028] In addition, Figure 5 In the configuration shown, the arrangement of nozzles 33 in the first nozzle row 34A and the second nozzle row 34B is inclined relative to the short side direction (Y direction; main scanning direction) of the coating head 31. However, this arrangement of nozzles 33 may not be used. For example, the nozzle row 34 may also be arranged along the short side direction (Y direction) of the coating head 31. In addition, the nozzle row 34 may not be divided into the first nozzle row 34A and the second nozzle row 34B in the short side direction (Y direction; main scanning direction) of the coating head 31, but may be a single nozzle row 34, or it may be divided into three or more nozzle rows.

[0029] Inside the aforementioned coating head 31, there is an internal flow path 36 for supplying paint flow (see reference). Figure 7 Additionally, a nozzle pressurization chamber 37 is provided inside the coating head 31 (see reference). Figure 7 On one wall surface of the nozzle pressurization chamber 37, a piezoelectric substrate 35 is disposed for causing a change in the volume of the nozzle pressurization chamber 37 to eject coating material from the nozzle 33 (see reference). Figure 7 Therefore, by applying a voltage to the piezoelectric substrate 35 from the outside, the piezoelectric substrate 35 expands and contracts, causing a change in the volume of the nozzle pressure chamber 37, thereby enabling the coating to be ejected from the nozzle 33.

[0030] It should be noted that the painting head 31 is not limited to Figure 5 The structure shown. For example, as Figure 6 As shown, a nozzle array 34 can also be formed by arranging multiple nozzles 33 along the short side direction (width direction; Y direction) of the coating head 31. Additionally, in use... Figure 6 When the paint head 31 shown is used to paint the vehicle FR, the painting can be performed with the long side of the paint head 31 slightly tilted relative to the main scanning direction of the paint head 31.

[0031] For example, if in Figure 5 In the structure of the coating head 31 shown, the nozzle array 34 is tilted at an angle α relative to the main scanning direction. Therefore, as long as... Figure 6 The long side of the coating head 31 can be tilted at an angle α relative to the main scanning direction of the coating head 31. With this tilt, by simply adjusting the timing of paint ejection from each nozzle 33, it is possible to achieve [the desired effect]. Figure 5 The coating head 31 shown is coated in the same way.

[0032] Figure 7 This is a diagram showing a schematic configuration for supplying paint to each nozzle 33 of the coating head 31. As shown... Figure 7 As shown, the coating head 31 has an internal flow path 36. The internal flow path 36 is a flow path that supplies paint to the nozzle pressurization chamber 37 via the paint supply path 52, described later. Furthermore, in Figure 7 The diagram shows an internal flow path 36. However, multiple nozzles 33 are formed in the coating head 31, thus providing multiple internal flow paths 36 in the coating head 31.

[0033] Furthermore, the number of nozzle pressurization chambers 37 corresponds to the number of nozzles 33, and the paint inside can be ejected from the nozzles 33 by driving the piezoelectric substrate 35. Additionally, the nozzle pressurization chambers 37 are connected to the return flow path 53 (described later) within the coating head 31 via an internal flow path 36 (not shown) such as a nozzle discharge flow path. Therefore, paint not ejected from the nozzles 33 returns to the return flow path 53.

[0034] With this configuration, the paint supply and cleaning mechanism 50 (described later) is used (see reference). Figure 8 The supplied paint is sprayed from the nozzle 33 through the internal flow path 36 and the nozzle pressurization chamber 37. In addition, the paint that is not sprayed from the nozzle 33 returns from the nozzle pressurization chamber 37 through the internal flow path 36 to the return flow path 53 described later.

[0035] In the painting robot 10 and cleaning system 1 configured as described above, the portion (robot body) from the moving table 16, through the robot arm R1, to the painting head unit 30 can move along the track 17. On the other hand, the cleaning tank 63 and drain tank 65 constituting the cleaning system 1 are not mounted on the robot arm R1, but are instead located at a specific point on the painting robot 10 (such as a mounting surface). Therefore, as... Figure 1 As shown, in most cases, the length of the return flow path 53 becomes longer, and the paint supply path 52 also becomes longer.

[0036] In a configuration where both the length of the return flow path 53 and the length of the paint supply path 52 are increased, the discharge capacity (suction capacity) of the cleaning fluid (described later) is insufficient in most cases during cleaning of various parts of the paint supply and cleaning mechanism 50, leading to reduced cleaning performance and increased cleaning time. However, the configuration described later can solve the problems of reduced cleaning performance and increased cleaning time.

[0037] (1-4. Regarding paint supply and cleaning facilities 50) Next, the paint supply and cleaning mechanism 50 will be described. (For example...) Figure 4As shown, the paint supply and 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, three-way valves 71-74 (1st to 4th), switching valves 81-86 (1st to 6th), a first vacuum ejector 91, a second vacuum ejector 92, a cap 93, and a cap moving mechanism 94 (see reference). Figure 8 Other pipelines, etc.

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

[0039] Here, each component of the paint supply and cleaning mechanism 50, including the paint circulation path 51 described above, can also be supplied with cleaning fluid (cleaning fluid) in addition to paint. However, it will be described below only as a structure for supplying "paint".

[0040] The return flow path 53 is connected to the internal flow path 36 within the coating head 31 and is used to return paint that is not sprayed from the coating head 31 to the paint tank 57.

[0041] In addition, the bypass flow path 54 is a flow path that connects the paint supply path 52 and the return flow path 53. That is, the bypass flow path 54 is set up in parallel with the coating head 31, and when no paint is sprayed from the coating head 31, the paint is made to flow into the bypass flow path 54 by switching the operation of the second three-way valve 72 and the third three-way valve 73, which will be described later.

[0042] External supply line 55 is a pipeline used to supply paint from the paint storage area, such as a circulation tank, to 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, forming a circulation path including the paint tank 57, and is a flow path used for cleaning within the circulation path.

[0044] Paint tank 57 is a portion used for temporary storage of paint supplied from external supply path 55. Furthermore, paint tank 57 may also have a function for removing air bubbles contained in the paint. This paint tank 57 is, for example, located at a stable position outside the robot arm R1 where its posture does not change. Additionally, paint tank 57 is connected to paint supply path 52 for supplying paint, and is connected to return flow path 53 such that paint is supplied from the return flow path 53.

[0045] The removal filter 58 removes foreign matter contained in the paint flowing within the paint supply path 52. For example, the removal filter 58 reliably removes large foreign matter and pigment agglomerates from paint containing pigments, thereby ensuring the continuous normal operation of the coating head 31. Furthermore, the removal filter 58 is positioned between the second switching valve 82 and the third switching valve 83 in the paint supply path 52.

[0046] The degassing module 59, compared to the aforementioned removal filter 58, is located downstream of the paint supply path 52 and is a component used to remove (degas) dissolved gases in the paint. Furthermore, the degassing module 59 is positioned between the third switching valve 83 and the fourth switching valve 84 in the paint supply path 52.

[0047] The supply pump 61 is a mechanism for applying positive pressure to the paint flowing in the paint supply path 52 toward a position downstream of the supply pump 61.

[0048] Furthermore, a gear pump, capable of controlling the amount of paint supplied by controlling the rotational speed, is preferably used as the supply pump 61. In this case, by reversing the rotation of the supply pump 61, which is a gear pump, the paint and cleaning fluid can be reversed. However, a pump other than a gear pump can also be used as the supply pump 61.

[0049] The suction pump 62 is a mechanism that applies negative pressure to the paint flowing in the return flow path 53 towards a position upstream of the suction pump 62. Furthermore, the suction pump 62 corresponds to a suction mechanism.

[0050] As the suction pump 62, similar to the supply pump 61 described above, a gear pump that can control the amount of paint supplied by controlling the rotational speed is preferably used. In this case, by reversing the rotation of the suction pump 62, which is a gear pump, the paint and cleaning fluid can be reversed. However, a pump other than a gear pump can also be used as the suction pump 62.

[0051] The cleaning tank 63 is a section for storing cleaning fluid, and it supplies the cleaning fluid used when cleaning the various parts of the paint supply and cleaning mechanism 50 and the painting head 31. The delivery pump 64 is a section that introduces the cleaning fluid stored in the cleaning tank 63 and delivers the introduced cleaning fluid to the cleaning switching valve 67. In addition, the delivery pump 64 corresponds to the pressurization mechanism.

[0052] In addition, the drain tank 65 is a part used to store the cleaning fluid (drain) discharged after cleaning of various parts of the paint supply and cleaning mechanism 50 and the painting head 31.

[0053] The compressor 66 is the part that supplies cleaning air to the cleaning switching valve 67. Furthermore, the cleaning switching valve 67 has multiple valve sections, including, for example, a valve section 67a connected to a flow path extending from the cleaning tank 63, a valve section 67b connected to a flow path extending from the compressor 66, and a valve section 67c connected to flow paths extending to the first to sixth switching valves 81 to 86 (described later). These multiple valve sections are independently opened and closed by the cleaning control unit 150 (described later). Through the above opening and closing control, cleaning fluid from the cleaning tank 63 and air from the compressor 66 are alternately fed into the paint supply path 52 or return flow path 53 in the paint circulation path 51.

[0054] Additionally, a first three-way valve 71 is positioned 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 numerals omitted) leading to the drain trough 65. This first three-way valve 71 can cut off the flow of paint or cleaning fluid between the first three-way valve 71 and any one of the following: (a) the paint tank 57 side, (b) the first switching valve 81 side, or (c) the drain trough 65 side. Therefore, paint or cleaning fluid can flow in the remaining two uninterrupted 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 coating head 31, and is also connected to one end of the bypass flow path 54. The second three-way valve 72 is capable of cutting off the flow of paint or cleaning fluid between the second three-way valve 72 and any one of (a) the fourth switching valve 84 side, (b) the coating head 31 side, or (c) the bypass flow path 54 side.

[0056] Additionally, a third three-way valve 73 is disposed between the coating head 31 and the fifth switching valve 85, and is also connected to the other end of the bypass flow path 54. This third three-way valve 73 is capable of cutting off the flow of paint or cleaning fluid between the third three-way valve 73 and any one of (a) the coating head 31 side, (b) the fifth switching valve 85 side, or (c) the bypass flow path 54 side.

[0057] Additionally, a fourth three-way valve 74 is positioned between the sixth switching valve 86 and the paint tank 57, and is also connected to a branch path (reference numerals omitted) leading to the drain trough 65. This fourth three-way valve 74 is capable of cutting off the flow of paint or cleaning fluid between the fourth three-way valve 74 and any one of the following sides: (a) the side of the sixth switching valve 86, (b) the side of the paint tank 57, or (c) the side of the drain trough 65.

[0058] Additionally, a first switching valve 81 is positioned between the first three-way valve 71 and the second switching valve 82 in the paint supply path 52. This first switching valve 81 has four valve sections 81a to 81d, which can switch the flow paths of liquid (paint, cleaning fluid) and air (air used during cleaning) depending on the opening and closing states of these valve sections 81a to 81d. Specifically, valve section 81a is connected to the upstream side of the paint supply path 52, and valve section 81b is connected to the downstream side of the paint supply path 52. Furthermore, valve section 81c is connected to a cleaning switching valve 67 that can be switched relative to the cleaning tank 63 or the compressor 66. Additionally, valve section 81d is connected to the second bypass flow path 56.

[0059] Therefore, when paint is supplied from paint tank 57 to coating head 31, or during paint circulation, valves 81a and 81b are opened, and paint from paint tank 57 flows downstream of paint supply path 52. Furthermore, during cleaning, if one of valves 81a and 81b, and valve 81c, are opened, cleaning fluid supplied from cleaning tank 63, or air supplied from compressor 66, flows through the opened valve into the flow path connected to that valve. In the following description, a fluid including at least one of the cleaning fluid and air used during cleaning will be used as the cleaning fluid.

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

[0061] Furthermore, the second switching valve 82 is connected to a position in the paint supply path 52 that is downstream of the first switching valve 81 and upstream of the removal filter 58. Like the first switching valve 81, the second switching valve 82 has four valve sections 82a to 82d, which can switch the flow paths of liquid (paint, cleaning fluid) and gas (air used during cleaning) depending on the opening and closing states of these valve sections 82a to 82d. Specifically, valve section 82a is connected to the upstream side of the paint supply path 52, and valve section 82b is connected to the downstream side of the paint supply path 52. Additionally, valve section 82c is connected to a cleaning switching valve 67 that can be switched relative to the cleaning tank 63 or the compressor 66. Furthermore, valve section 82d is connected to the drain tank 65 via a vacuum ejector 91.

[0062] Therefore, when paint is supplied from paint tank 57 to coating head 31, or during paint circulation, valves 82a and 82b are opened, and paint from paint tank 57 flows downstream of paint supply path 52. Furthermore, during cleaning, if one of valves 82a and 82b, and valve 82c, are opened, cleaning fluid flows through the opened valve into the flow path connected to that valve.

[0063] Furthermore, the third switching valve 83 is connected to the paint supply path 52 at a position 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 described above, the third switching valve 83 has four valve sections 83a to 83d, which can switch the flow paths of liquid (paint, cleaning fluid) and gas (air used during cleaning) depending on the opening and closing states of these valve sections 83a to 83d. Specifically, valve section 83a is connected to the upstream side of the paint supply path 52, and valve section 83b is connected to the downstream side of the paint supply path 52. Additionally, valve section 83c is connected to a cleaning switching valve 67 that can be switched relative to the cleaning tank 63 or the compressor 66. Furthermore, valve section 83d is connected to the drain tank 65 side.

[0064] Therefore, when paint is supplied from paint tank 57 to coating head 31, or during paint circulation, valves 83a and 83b are opened, and paint from paint tank 57 flows downstream of paint supply path 52. Furthermore, during cleaning, if one of valves 83a and 83b, and valve 83c, are opened, cleaning fluid flows through the opened valve into the flow path connected to that valve.

[0065] Furthermore, the fourth switching valve 84 is connected to the paint supply line 52 at a position downstream of the third switching valve 83 and the degassing module 59 and upstream of the second three-way valve 72. This fourth switching valve 84 differs from the first switching valve 81 described above, and has six valve sections 84a to 84f, which can switch the flow paths of liquid (paint, cleaning fluid) and gas (air used during cleaning) according to the opening and closing states of these valve sections 84a to 84f.

[0066] Specifically, valve 84a is connected to the upstream side of paint supply passage 52, and valve 84b is connected to the downstream side of paint supply passage 52. Therefore, if valves 84a and 84b are opened, paint from the upstream side of paint supply passage 52 flows to the second three-way valve 72 on the downstream side of paint supply passage 52. Furthermore, valve 84a is connected to valve 84f independently of valves 84b, 84c, and 84e. Therefore, when valves 84c or 84e and valve 84b are opened, and cleaning fluid or air, or paint, flows to these valves, valve 84a can be connected to valve 84f independently of this flow.

[0067] In addition, valve 84c is connected to a cleaning switching valve 67 that can be switched relative to the cleaning tank 63 or the compressor 66. Therefore, when cleaning, if valve 84a or valve 84b and valve 84c are opened, the cleaning fluid flows through the opened valve to the flow path connected to that valve.

[0068] Furthermore, valve section 84d is connected to the cleaning switching valve 67 independently of valve section 84c. The flow path of valve section 84d is not connected to valve sections 84b, 84c, or 84e, but only to valve sections 84a and 84f. For example, if valve sections 84d and 84f are opened, the cleaning fluid flows to the drain tank 65 via the opened valve section 84f.

[0069] Furthermore, valve 84e is connected to drain tank 65 via the first vacuum ejector 91, which will be described later. Therefore, if the first vacuum ejector 91 is operated while one of the valves 84a or 84b is open and valve 84e is open, the cleaning fluid that has been cleaned is discharged into drain tank 65 via valve 84e and vacuum ejector 91.

[0070] Additionally, valve 84f is also connected to the drain trough 65. The flow path of valve 84f is not connected to valves 84b, 84c, or 84e, but is connected to valves 84a and 84d. If valves 84a and 84f are opened, the paint drain from the upstream side of the paint supply path 52 flows through valves 84a and 84f into the drain trough 65.

[0071] Furthermore, the fifth switching valve 85 is connected to the return flow path 53 at a position downstream of the third three-way valve 73 and upstream of the suction pump 62. Like the fourth switching valve 84 described above, the fifth switching valve 85 has six valve sections 85a to 85f, which allow switching of the flow paths for liquids (coatings, cleaning fluids) and air based on the opening and closing states of these valve sections 85a to 85f.

[0072] Specifically, valve 85a is connected to the upstream side of the return flow path 53, and valve 85b is connected to the downstream side of the return flow path 53. Therefore, if valves 85a and 85b are opened, the paint from the upstream side of the return flow path 53 flows towards the suction pump 62 on the downstream side of the return flow path 53. Furthermore, valve 85b is connected to valve 85f independently of valves 85a, 85c, and 85e. Therefore, when valves 85c or 85e and valve 85b are opened, and cleaning fluid or paint flows into these valves, valve 85b can be connected to valve 85f independently of this flow.

[0073] In addition, valve 85c is connected to cleaning switching valve 67. Therefore, during cleaning, if one of valves 85a or 85b and valve 85c is opened, the cleaning fluid flows through the opened valve into the flow path connected to that valve.

[0074] Furthermore, valve section 85d is connected to the cleaning switching valve 67 independently of valve section 85c described above. The flow path of valve section 85d is not connected to valve sections 85a, 85c, or 85e, but only to valve sections 85b and 85f. For example, if valve sections 85d and 85f are opened, the cleaning fluid flows to the drain tank 65 via the opened valve section 85f.

[0075] Furthermore, valve 85e is connected to drain tank 65 via the second vacuum ejector 92, which will be described later. Therefore, if the second vacuum ejector 92 is operated while one of the valves 85a or 85b is open and valve 85e is open, the cleaning fluid that has been cleaned is discharged into drain tank 65 via valve 85e and the second vacuum ejector 92.

[0076] Additionally, valve 85f is connected to valves 85b and 85d, as well as the drain trough 65. The flow path of valve 85f is not connected to valves 85a, 85c, or 85e, but is connected to valves 85b and 85d. If valves 85b and 85f are opened, the paint drain fluid returning to the downstream side of flow path 53 flows through valves 85b and 85f to the drain trough 65.

[0077] Additionally, a sixth switching valve 86 is positioned between the suction pump 62 and the fourth three-way valve 74 in the return flow path 53. This sixth switching valve 86 has four valve sections 86a to 86d, which can switch the flow paths of liquids (coatings, cleaning fluids) and air depending on the opening and closing states of these valve sections 86a to 86d. Specifically, valve section 86a is connected to the upstream side of the return flow path 53, and valve section 86b is connected to the downstream side of the return flow path 53. Furthermore, valve section 86c is connected to a cleaning switching valve 67 that can be switched relative to the cleaning tank 63 or the compressor 66. Additionally, valve section 86d is connected to the second bypass flow path 56.

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

[0079] Furthermore, as described above, valve section 86d is connected to valve section 81d of the first switching valve 81 via the second bypass flow path 56. Therefore, if valve sections 81a and 81d of the first switching valve 81 are opened, and valve sections 86d and 86b of the sixth switching valve 86 are opened, the second bypass flow path 56 connecting valve sections 81d and 86d is opened. This forms a circulation path in which the paint circulates within these sections in the order of paint tank 57, first switching valve 81, second bypass flow path 56, and sixth switching valve 86.

[0080] Furthermore, the first vacuum ejector 91 is disposed midway in the pipeline connecting the valve section 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 in operation, paint or cleaning fluid can be discharged from the coating head 31 side at a specified pressure when the valve section 84b and valve section 84e are open.

[0081] Furthermore, the second vacuum ejector 92 is positioned midway in the pipeline connecting the valve section 85e and the drain tank 65. Like the first vacuum ejector 91, the second vacuum ejector 92 is a device that discharges fluid by generating a vacuum. When the second vacuum ejector 92 is in operation, it allows paint or cleaning fluid to be discharged from the coating head 31 side at a predetermined pressure when the valve sections 85a and 85e are open.

[0082] Furthermore, the first vacuum ejector 91 and the second vacuum ejector 92 are configured to have a sufficiently high suction force compared to the suction pump 62. In detail, 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 generated by the suction of the first vacuum ejector 91 and the second vacuum ejector 92 is greater than the negative pressure generated by the suction of the suction pump 62. However, it is also possible that the negative pressure generated by the suction of the first vacuum ejector 91 and the second vacuum ejector 92 is less than or equal to the negative pressure generated by the suction of the suction pump 62.

[0083] Furthermore, at least one of the first vacuum ejector 91 and the second vacuum ejector 92 corresponds to the cleaning suction mechanism. Additionally, either the first vacuum ejector 91 or the second vacuum ejector 92 corresponds to the first cleaning suction mechanism, and the other of the first vacuum ejector 91 and the second vacuum ejector 92 corresponds to the second cleaning suction mechanism.

[0084] The cap 93 is a component that abuts against and seals the nozzle forming surface 32 in close contact with it, wherein the nozzle 33 is exposed on the nozzle forming surface 32. The cap 93 is preferably formed of a flexible and deformable component, such as rubber. Alternatively, the cap 93 may be configured to form a small space (internal space) between the nozzle forming surfaces 32, allowing paint droplets to drain into this internal space. In this case, it is preferable that the peripheral wall forming the internal space of the cap 93 does not directly abut against the portion of the nozzle forming surface 32 where the nozzle 33 is formed. Furthermore, it is preferable that a drain pipe for draining paint droplets is connected to the cap 93.

[0085] Additionally, the cap moving mechanism 94 is a mechanism for moving the cap 93 to close or release the nozzle forming surface 32. This cap moving mechanism 94 can be a separate mechanism having a drive source such as a motor and actuator, and a transmission mechanism such as a cam and gear for transmitting the driving force from the drive source. However, the cap moving mechanism 94 can also be a robot arm R1 capable of moving the coating head 31 (coating head unit 30) relative to the cap 93.

[0086] (1-5. Regarding the control unit 100) Next, the general configuration of the control unit 100 used to control the operation of the cleaning system 1 of the painting robot 10 will be described. Figure 8 This is a diagram showing a schematic configuration related to control, centered on the control unit 100 of the cleaning system 1 of the painting robot 10. Figure 8 As shown, the control unit 100 includes 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. Furthermore, at least one of the control unit 100, the main control unit 110, and the cleaning control unit 150 corresponds to a control mechanism.

[0087] During the coating process, the main control unit 110 in the aforementioned control-related configuration sends prescribed control signals to the robot arm control unit 120, head control unit 130, and paint supply control unit 140 as needed, so that each motor of the robot arm R1, each working part of the paint supply and cleaning mechanism 50, and the piezoelectric substrate 35 cooperate to perform coating on the object to be coated.

[0088] When cleaning is performed, the main control unit 110 sends specified control signals to the robot arm control unit 120, head control unit 130, paint supply control unit 140, and cleaning control unit 150 as needed, so that each motor of the robot arm R1, each working part of the paint supply and cleaning mechanism 50, and the piezoelectric substrate 35 cooperate to perform cleaning on the object to be coated.

[0089] The robot arm control unit 120 is the part that controls the drive of each motor of the robot arm R1.

[0090] The head control unit 130 is a unit that controls the operation of the piezoelectric substrate 35 within the coating head unit 30 based on image processing within an image processing apparatus (not shown). Alternatively, the head control unit 130 may also control the operation of the piezoelectric substrate 35 as needed when cleaning is performed within the coating head 31.

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

[0092] The cleaning control unit 150 controls the operation of relevant working parts when cleaning is performed on the internal flow path 36 within the coating head 31 and the various components within the paint circulation path 51 using cleaning fluids (cleaning liquid and air). Specifically, the cleaning control unit 150 controls the operation of each working part of the paint supply and cleaning mechanism 50, including 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. Control during cleaning) Next, we will explain the detailed control of cleaning the internal flow path 36 within the coating head 31. (2-1. About forward cleaning) First, let's explain the forward cleaning process. Figure 9 This diagram illustrates the cleaning process in the internal flow path 36 within the coating head 31. In this forward cleaning, similar to normal coating, cleaning fluids such as cleaning solution and air are supplied from the paint supply path 52 towards the coating 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, opening valve section 67b and closing valve section 67a. Furthermore, the cleaning control unit 150 activates the second three-way valve 72 to cut off the flow of cleaning fluid to the bypass flow path 54, and activates the third three-way valve 73 to cut off the supply of cleaning fluid from the bypass flow path 54.

[0094] Additionally, the cleaning control unit 150 operates the compressor 66, preparing it to supply cleaning air to the valve unit 67c. Furthermore, separately as described above, the cleaning control unit 150 operates the cap moving mechanism 94, bringing the cap 93 into close contact with the nozzle forming surface 32. This results in the nozzle forming surface 32 (nozzle 33) being closed from the outside.

[0095] Then, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84b and 84c and close the other valve sections 84a, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the fifth switching valve 85 to open valve sections 85a and 85e and close the other valve sections 85b, 85c, 85d, and 85f.

[0096] Furthermore, the cleaning air flows through valves 67b, 67c and 84b, 84c for a predetermined time (e.g., 0.5 seconds). Figure 9 (a) Start-up of the air supply). Then, one of valves 84b and 84c is cut off to cut off the air supply. Figure 9 (a) The air supply is stopped. Then, preferably, the valve 84e is opened to release the air and adjust the pressure. Figure 9 (a) Release start). At this time, the air pressure is preferably 0.3 to 0.4 bar. However, it can also be a pressure outside this range. In particular, when using the coating head 31 which seeks high pressure resistance, it is preferable to set it to a pressure range higher than that described above.

[0097] Next, the cleaning control unit 150 operates the delivery pump 64, setting it to a ready state to supply cleaning fluid. Then, the cleaning control unit 150 sets the valves 84b and 84c to be open and the other valves 84a, 84d, 84e, and 84f to be closed, and switches the cleaning switching valve 67 so that valve 67a is open and valve 67b is closed.

[0098] Furthermore, the cleaning fluid flows through valve sections 67a, 67c and 84b, 84c for a predetermined time (e.g., 15 seconds). Figure 9 (a) Start-up of the cleaning fluid supply). Then, one of valves 84b and 84c is cut off to cut off the supply of the cleaning fluid. Figure 9 (a) The supply of cleaning fluid is stopped. Thus, cleaning fluid 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 fluid is preferably set to 0.3 to 0.4 bar. However, a pressure outside this range is also possible. In particular, when using a coating head 31 that requires high pressure resistance, a pressure range higher than described above is preferred.

[0099] Furthermore, the air or cleaning fluid that has cleaned the internal flow path 36 is discharged into the drain tank 65 via the return flow path 53 and valve sections 85a and 85e. During this discharge, the cleaning control unit 150 activates the second vacuum ejector 92, using negative pressure to discharge the cleaned cleaning fluid or air into the drain tank 65. This increases the amount of cleaning fluid or air introduced into the internal flow path 36.

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

[0101] Furthermore, by operating the second vacuum ejector 92, even if the return flow path 53 and the paint supply path 52 are long, the discharge performance of the cleaning fluid after cleaning can be improved compared to the case where the cleaning fluid is discharged solely by operating the delivery pump 64.

[0102] In particular, when the cleaning fluid is discharged through the valve section 85e of the fifth switching valve 85, the suction pump 62 is not used. Therefore, in the configuration that does not use the second vacuum ejector 92 as a comparative example, the drive unit for discharging the cleaning fluid is only the delivery pump 64, and the discharge performance after cleaning is easily reduced.

[0103] However, by providing a second vacuum ejector 92 as described above, the cleaning fluid is discharged after cleaning, in addition to the operation of the delivery pump 64. This improves the discharge performance of the cleaning fluid after cleaning compared to the case where only the delivery pump 64 is operated. In other words, even if the return flow path 53 and the paint supply path 52 are long during forward cleaning, the reduction in cleaning performance of the paint circulation path 51 and the increase in cleaning time can be suppressed.

[0104] Furthermore, if the forward cleaning of the internal flow path 36 based on air and cleaning fluid as described above is considered as a cycle, it is preferable to repeat the cleaning cycle more than twice.

[0105] (2-2. About reverse cleaning) Next, reverse cleaning will be described. In this reverse cleaning, cleaning fluids such as cleaning liquid and air are supplied to the coating head 31 in the opposite direction to the forward cleaning described above. In this case, based on the command of the main control unit 110, the cleaning control unit 150 switches the cleaning switching valve 67, opening valve section 67b and closing valve section 67a. In addition, the cleaning control unit 150 operates the second three-way valve 72 to cut off the flow of cleaning fluid to the bypass flow path 54, and operates the third three-way valve 73 to cut off the supply of cleaning fluid from the bypass flow path 54.

[0106] Additionally, the cleaning control unit 150 operates the compressor 66, preparing it to supply cleaning air to the valve unit 67c. Furthermore, separately as described above, the cleaning control unit 150 operates the cap moving mechanism 94, bringing the cap 93 into close contact with the nozzle forming surface 32. This results in the nozzle forming surface 32 (nozzle 33) being closed from the outside.

[0107] Then, the cleaning control unit 150 switches the fifth switching valve 85 to open valve sections 85a and 85c and close the other valve sections 85b, 85d, 85e, and 85f. Furthermore, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84b and 84e and close the other valve sections 84a, 84c, 84d, and 84f.

[0108] Furthermore, the cleaning air flows through valves 67b, 67c and valves 85a, 85c for a predetermined time (e.g., 0.5 seconds). Figure 9 (b) Start-up of the air supply). Then, one of valves 85a and 85c is cut off to cut off the air supply. Figure 9 (b) The air supply is stopped. Then, preferably, the valve 85e is opened to release air and pressure is adjusted. Figure 9 (b) release of the initiation).

[0109] Next, the cleaning control unit 150 operates the delivery pump 64, setting it to a ready state to supply cleaning fluid. Then, with valves 85a and 85c open and other valves 85b, 85d, 85e, and 85f closed, the cleaning control unit 150 switches the cleaning switching valve 67 to open valve 67a and close valve 67b.

[0110] Furthermore, the cleaning fluid flows through valve sections 67a, 67c and 85a, 85c for a predetermined time (e.g., 15 seconds). Figure 9 (b) Start-up of the cleaning fluid supply). Then, one of valves 85a and 85c is cut off to cut off the supply of the cleaning fluid. Figure 9(b) The cleaning fluid supply is stopped. Thus, cleaning fluid is supplied to the internal flow path 36 of the coating head 31 via the paint supply path 52.

[0111] Furthermore, the air or cleaning fluid that has cleaned the internal flow path 36 is discharged into the drain tank 65 via the paint supply path 52 and valve sections 84b and 84e. During this discharge, the cleaning control unit 150 activates the first vacuum ejector 91, using negative pressure to discharge the cleaned cleaning fluid or air into the drain tank 65. This increases the amount of cleaning fluid or air introduced into the internal flow path 36.

[0112] If this is done, air and cleaning fluid at a specified pressure are alternately supplied to the internal flow path 36 via the return flow path 53 at a specified pressure. This performs reverse cleaning of the internal flow path 36. At this time, the nozzle forming surface 32 (nozzle 33) is closed by the cap 93, so the internal flow path 36 can be pressurized and cleaning can be performed in this pressurized state.

[0113] Furthermore, as described above, in addition to the operation of the delivery pump 64, the cleaning fluid after cleaning is also discharged through the operation of the first vacuum ejector 91. This improves the discharge performance of the cleaning fluid after cleaning compared to the case where only the delivery pump 64 is operated. In other words, even if the return flow path 53 and the paint supply path 52 are long in reverse cleaning, the reduction in cleaning performance of the paint circulation path 51 and the increase in cleaning time can be suppressed.

[0114] Furthermore, if the reverse cleaning of the internal flow path 36 based on air and cleaning fluid as described above is considered as a cycle, it is preferable to repeat the cleaning cycle more than twice.

[0115] (3. Variations) (3-1. Cleaning when there is only one vacuum ejector) In the above embodiment, two vacuum ejectors, a first vacuum ejector 91 and a second vacuum ejector 92, are used as vacuum ejectors. However, it is also possible to use a single vacuum ejector for both forward and reverse cleaning. In this case, cleaning can be performed on each area designated as a cleaning target. The following is based on... Figure 10 Please explain this situation. Furthermore, Figure 10 In this description, vacuum ejector 95 is explained as a vacuum ejector. Here, vacuum ejector 95 corresponds to the cleaning suction mechanism, and also to either the first or second cleaning suction mechanism. However, it is also possible that the first to sixth switching valves 81 to 86 are included in the cleaning suction mechanism, or either the first or second cleaning suction mechanism.

[0116] (3-1a. On forward cleaning) First, let's explain forward cleaning. In this case, we'll describe the cleaning target as the first zone, which includes the internal flow path 36 of the coating head 31, the paint supply path 52 leading to the internal flow path 36, and the return flow path 53 for the cleaning fluid discharged from the internal flow path 36. 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 in the same manner as in the embodiment described above. Then, it switches the fourth switching valve 84 to open valve sections 84b and 84c and close the other valve sections 84a, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the second switching valve 85 to open valve sections 85a and 85e and close the other valve sections 85b, 85c, 85d, and 85f.

[0117] Furthermore, the details of the subsequent cleaning are the same as those in "2-1. Regarding forward cleaning" above, so their detailed description is omitted.

[0118] Furthermore, the air or cleaning fluid that has cleaned the internal flow path 36 is discharged into the drain tank 65 via the return flow path 53 and valve sections 85a and 85e. During this discharge, the cleaning control unit 150 activates the vacuum ejector 95, using negative pressure to discharge the cleaned cleaning fluid or air into the drain tank 65. Therefore, compared to the case where the suction pump 62 is activated, the amount of cleaning fluid or air introduced into the internal flow path 36 can be increased.

[0119] Here, the cleaning control unit 150 may, for example, operate the cap moving mechanism 94 to adjust the tight contact state of the cap 93 with the nozzle forming surface 32, and control the operation of the vacuum ejector 95 to change the negative pressure generated by the operation of the vacuum ejector 95, thereby making the ratio between the amount of cleaning fluid flowing in the internal flow path 36 ejected from the nozzle 33 and the amount that does not eject from the nozzle 33 but passes through the internal flow path 36 variable.

[0120] In other words, when the cap 93 is not in complete and tight contact with the nozzle forming surface 32, cleaning fluid will leak from the nozzle 33 to a predetermined extent. If, during this leakage, the negative pressure change generated by the operation of the vacuum ejector 95 allows for adjustment of the amount of cleaning fluid leaking from the nozzle 33 to an appropriate proportion. Therefore, even if foreign matter can be directly discharged from the nozzle 33 using the cleaning fluid, this situation can be addressed by adjusting the amount of cleaning fluid ejected from the nozzle 33.

[0121] If done as described above, air and cleaning fluid at a specified pressure are alternately supplied to the internal flow path 36 via the paint supply path 52 at a specified pressure. This performs forward cleaning of the internal flow path 36. At this time, the nozzle forming surface 32 (nozzle 33) is closed by the cap 93, thus enabling the internal flow path 36 to be pressurized and cleaning to be performed under this pressurized state.

[0122] Furthermore, by operating the vacuum ejector 95, even if the return flow path 53 and the paint supply path 52 are long, the discharge performance of the cleaning fluid after cleaning can be improved compared to the case where the cleaning fluid is discharged solely by operating the delivery pump 64.

[0123] In particular, when the cleaning fluid is discharged via the valve section 85e of the fifth switching valve 85, since there is no suction pump 62, in the configuration that does not use the vacuum ejector 95 as a comparative example, the drive unit for discharging the cleaning fluid is only the delivery pump 64, and the discharge performance after cleaning is easily reduced.

[0124] However, by providing a vacuum ejector 95 as described above, the cleaning fluid after cleaning is discharged in addition to the operation of the delivery pump 64. This improves the discharge performance of the cleaning fluid after cleaning compared to the case where only the delivery pump 64 is operated. In other words, even if the return flow path 53 and the paint supply path 52 are long during forward cleaning, the reduction in cleaning performance of the paint circulation path 51 and the increase in cleaning time can be suppressed.

[0125] Furthermore, if the forward cleaning of the internal flow path 36, which is carried out by air and cleaning fluid as described above, is set as a cycle, it is preferable to repeat the cleaning cycle more than twice.

[0126] Furthermore, when the cleaning target is a second section that includes the degassing module 59 within the first section of the internal flow path 36, as described above, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83b and 83c and close other valve sections 83a and 83d. Additionally, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close other valve sections 84c, 84d, 84e, and 84f. Moreover, the cleaning control unit 150 switches the second switching valve 85 to open valve sections 85a and 85e and close other valve sections 85b, 85c, 85d, and 85f.

[0127] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[0128] Furthermore, when the cleaning target is a third section that includes the removal of filter 58 within the second section, which is described above and whose main cleaning target is the internal flow path 36 and the degassing module 59, the second switching valve 82 is switched to open valve sections 82b and 82c and close other valve sections 82a and 82d. Additionally, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83a and 83b and close other valve sections 83c and 83d. Furthermore, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close other valve sections 84c, 84d, 84e, and 84f. Moreover, the cleaning control unit 150 switches the second switching valve 85 to open valve sections 85a and 85e and close other valve sections 85b, 85c, 85d, and 85f.

[0129] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[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, within the third section as described above, where the main cleaning target is the internal flow path 36, the degassing module 59, and the removal filter 58, the first switching valve 81 is switched to open valve sections 81b and 81c and close the other valve sections 81a and 81d. Additionally, the cleaning control unit 150 switches the second switching valve 82 to open valve sections 82a and 82b and close the other valve sections 82c and 82d. Furthermore, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83a and 83b and close the other valve sections 83c and 83d. Finally, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close the other valve sections 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the second switching valve 85 to open valve sections 85a and 85e and close other valve sections 85b, 85c, 85d, and 85f.

[0131] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[0132] (3-1b. On reverse cleaning) Next, reverse cleaning will be described. In this reverse cleaning, cleaning fluids such as cleaning liquid and air are supplied to the coating head 31 in the opposite direction to the forward cleaning described above. In this case, the cleaning target is described as the first zone, which includes the internal flow path 36 of the coating head 31, the paint supply path 52 leading to the internal flow path 36, and the return flow path 53 for the cleaning fluid discharged from the internal flow path 36. 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 in the same manner as in the embodiment described above. Then, the cleaning control unit 150 switches the fifth switching valve 85 to open valve sections 85a and 85c and close the other valve sections 85b, 85d, 85e, and 85f. Furthermore, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84b and 84e and close other valve sections 84a, 84c, 84d, and 84f.

[0133] Furthermore, the details of the subsequent cleaning process are the same as those in "2-2. Regarding reverse cleaning" above, so their detailed explanation is omitted.

[0134] Furthermore, the air or cleaning fluid that has cleaned the internal flow path 36 is discharged into the drain tank 65 via the paint supply path 52 and valve sections 84b and 84e. During this discharge, the cleaning control unit 150 activates the vacuum ejector 95, using negative pressure to discharge the cleaned cleaning fluid or air into the drain tank 65. This increases the amount of cleaning fluid or air introduced into the internal flow path 36.

[0135] If this is done, air and cleaning fluid at a specified pressure are alternately supplied to the internal flow path 36 via the return flow path 53 at a specified pressure. This performs reverse cleaning of the internal flow path 36. At this time, the nozzle forming surface 32 (nozzle 33) is closed by the cap 93, so the internal flow path 36 can be pressurized and cleaning can be performed in this pressurized state.

[0136] Furthermore, as described above, by installing a vacuum ejector 95, the cleaning fluid after cleaning is discharged in addition to the operation of the delivery pump 64. This improves the discharge performance of the cleaning fluid compared to operating only the delivery pump 64. In other words, even with long return flow path 53 and paint supply path 52 in reverse cleaning, the reduction in cleaning effectiveness and the increase in cleaning time in the paint circulation path 51 can be suppressed.

[0137] Furthermore, if the reverse cleaning of the internal flow path 36, which is carried out by air and cleaning fluid as described above, is considered as a cycle, it is preferable to repeat the cleaning cycle more than twice.

[0138] Furthermore, when the cleaning target is reverse cleaning in the second section, which includes the degassing module 59 within the first section of the internal flow path 36 as described above, the cleaning control unit 150, as described above, switches the fifth switching valve 85 to open valve sections 85a and 85c and close other valve sections 85b, 85d, 85e, and 85f. Additionally, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close other valve sections 84c, 84d, 84e, and 84f. Moreover, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83b and 83d and close other valve sections 83a and 83c.

[0139] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[0140] Furthermore, when the cleaning target is reverse cleaning in the third section, which includes the removal filter 58 within the second section of the internal flow path 36 and the degassing module 59, as described above, the cleaning control unit 150, as described above, switches the fifth switching valve 85 to open valve sections 85a and 85c and close other valve sections 85b, 85d, 85e, and 85f. Additionally, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close other valve sections 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83a and 83b and close other valve sections 83c and 83d. Finally, the cleaning control unit 150 switches the second switching valve 82 to open valve sections 82b and 82d and close other valve sections 82a and 82c.

[0141] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[0142] Furthermore, when reverse cleaning is performed in the third section, which includes the paint supply path 52 between the first switching valve 81 and the second switching valve 82, and the main cleaning target is the internal flow path 36, the degassing module 59, and the removal filter 58, as described above, the cleaning control unit 150 switches the fifth switching valve 85 to open valve sections 85a and 85c and close other valve sections 85b, 85d, 85e, and 85f, as described above. Additionally, the cleaning control unit 150 switches the fourth switching valve 84 to open valve sections 84a and 84b and close other valve sections 84c, 84d, 84e, and 84f. Furthermore, the cleaning control unit 150 switches the third switching valve 83 to open valve sections 83a and 83b and close other valve sections 83c and 83d. Finally, the cleaning control unit 150 switches the second switching valve 82 to open valve sections 82a and 82b and close other valve sections 82c and 82d. Additionally, the cleaning control unit 150 switches the first switching valve 81 to open valve sections 81a and 81b and close other valve sections 81c and 81d. Furthermore, the cleaning control unit 150 switches the first three-way valve 71 to prevent the cleaning fluid from flowing towards the paint tank 57 side and instead direct the cleaning fluid towards the drain tank 65 side.

[0143] Furthermore, the details of the subsequent cleaning are the same as those in the first interval mentioned above, so their detailed description is omitted.

[0144] (3-2. The cleaning fluid after cleaning is discharged from outside the 5th switching valve 85) In the aforementioned forward cleaning process, the cleaning fluid after cleaning is discharged from the valve portion 85e of the fifth switching valve 85 toward the drain tank 65. However, it is also possible that the cleaning fluid after cleaning is 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, for example, switches the fifth switching valve 85 to open valve sections 85a and 85b and close other valve sections 85c, 85d, and 85f. Additionally, the cleaning control unit 150 switches the sixth switching valve 86 to open valve sections 86a and 86b and close other valve sections 86c and 86d. Furthermore, the cleaning control unit 150 switches the fourth three-way valve 74 to direct the cleaning fluid away from the paint tank 57 side and towards the drain trough 65 side.

[0146] In this case, cleaning fluid can also flow in the return flow path 53 between the 5th switching valve 85 and the 6th switching valve 86 for cleaning. In addition, the cleaning fluid passes through the suction pump 62. Therefore, by operating the suction pump 62 on the basis of the delivery pump 64 (or vacuum ejector 95), the cleaning fluid after cleaning can be discharged more effectively toward the drain tank 65, which can further suppress the decrease in the cleanability of the paint circulation path 51 and the increase in cleaning time.

[0147] Additionally, as another example of fluid passing through at least the 6th switching valve 86, the cleaning control unit 150 switches the 5th switching valve 85 to open valve sections 85a and 85b and close other valve sections 85c, 85d, 85e, and 85f. Furthermore, the cleaning control unit 150 switches the 6th switching valve 86 to open valve sections 86a and 86d and close other valve sections 86b and 86c. Additionally, the cleaning control unit 150 switches the 1st switching valve 81 to open valve sections 81a and 81d and close other valve sections 81b and 81c. Moreover, the cleaning control unit 150 switches the 1st three-way valve 71 to prevent the cleaning fluid from flowing towards the paint tank 57 side and instead direct the cleaning fluid towards the drain tank 65 side.

[0148] In this case, cleaning fluid can also flow in the return flow path 53 between the 5th switching valve 85 and the 6th switching valve 86 for cleaning. Furthermore, cleaning fluid can also flow in the 2nd bypass flow path 56 for cleaning.

[0149] (3-3. The cleaning fluid is supplied from sources other than the 5th switching valve 85) In addition, in the reverse cleaning described above, cleaning fluid is supplied from the valve section 85c of the fifth switching valve 85. However, cleaning fluid may also be supplied from the valve section 85c of the sixth switching valve 86.

[0150] In this case, the cleaning control unit 150, for example, switches the sixth switching valve 86 to open valve sections 86a and 86c and close other valve sections 86b and 86d. Additionally, the cleaning control unit 150 switches the fifth switching valve 85 to open valve sections 85a and 85b and close other valve sections 85c, 85d, 85e, and 85f.

[0151] In this case, the cleaning fluid can also flow in the return flow path 53 between the 5th switching valve 85 and the 6th switching valve 86 for 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) Alternatively, the cleaning control unit 150 may supply cleaning fluid, such as cleaning liquid or air, from the first switching valve 81 during reverse cleaning, and supply cleaning fluid 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.

[0153] At this time, the first switching valve 81 is switched to open valve sections 81c and 81d and close the other valve sections 81a and 81b. Additionally, the sixth switching valve 86 is switched to open valve sections 86a and 86d and close the other valve sections 86b and 86c. Furthermore, the fifth switching valve 85 is switched to open valve sections 85a and 85b and close the other valve sections 85c, 85d, 85e, and 85f. Thus, cleaning fluid is supplied from the return flow path 53 to the internal flow path 36 via the first switching valve 81, the second bypass flow path 56, the sixth switching valve 86, and the fifth switching valve 85.

[0154] Furthermore, during the discharge of the cleaning fluid on the paint supply path 52 side, the second to fourth switching valves 82 to 84 are switched to discharge the cleaning fluid from at least one of the second to fourth switching valves 82 to 84. Specifically, when switching the second switching valve 82, the control operation opens valve sections 82b and 82d and closes the other valve sections 82a and 82c. Similarly, when switching the third switching valve 83, the control operation opens valve sections 83b and 83d and closes the other valve sections 83a and 83c. Furthermore, when switching the fourth switching valve 84, the control operation opens valve sections 84b and 84e and closes the other valve sections 84a, 84c, 84d, and 84f.

[0155] Thus, in reverse cleaning, when a cleaning fluid such as cleaning liquid or air is supplied from the first switching valve 81, and the cleaning fluid is supplied from the return flow path 53 side to the inner flow path 36 via the second bypass flow path 56 and the sixth switching valve 86, the return flow path 53 can be cleaned together with the coating head 31.

[0156] (3-5. Supply of cleaning fluid via the first switching valve 81, paint tank 57 and the sixth switching valve 86) Alternatively, the cleaning control unit 150 may supply cleaning fluid, such as cleaning liquid or air, from the first switching valve 81 during reverse cleaning, and supply cleaning fluid from the return flow path 53 side 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 to open valve sections 81a and 81c and close the other valve sections 81b and 81d. Additionally, a switch is made in the first three-way valve 71 to direct the cleaning fluid away from the drain tank 65 and towards the paint tank 57. Furthermore, a switch is made in the fourth three-way valve 74 to direct the cleaning fluid away from the drain tank 65 and towards the sixth switching valve 86.

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

[0159] Furthermore, 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 flow path 56, and the sixth switching valve 86, as described above, and therefore its description is omitted.

[0160] In this reverse cleaning process, the return flow path 53 can be cleaned together with the coating head 31. Additionally, the paint tank 57 can also be cleaned.

[0161] (3-6. Pressure variation caused by cap 93) In the above-described embodiments or variations, the cap moving mechanism 94 may be activated under the control of the cleaning control unit 150 during the execution of at least one of the cleaning actions, either forward or reverse cleaning, thereby causing fluctuations in the sealing pressure of the nozzle forming surface 32 and the internal flow path 36 generated by the cap 93. Alternatively, the pressure of the nozzle forming surface 32 may fluctuate after it has been opened from its closed state and then closed again.

[0162] By generating this pressure variation, the discharge of foreign matter in the internal flow path 36 can be improved.

[0163] (3-7. Other variations) In addition, in the above embodiment, the delivery pump 64 corresponds to the pressurization mechanism, but other components may be used instead of the delivery pump 64 as the pressurization mechanism. For example, if the cleaning fluid or air is supplied from a position upstream of the supply pump 61, the supply pump 61 may be corresponding to the pressurization mechanism.

[0164] Furthermore, in the above-described embodiments, the first vacuum ejector 91 and the second vacuum ejector 92 correspond to the cleaning suction mechanism, but other components may be used instead. For example, if the cleaning fluid or air is supplied from a position upstream of the return flow path 53 than the suction pump 62, the suction pump 62 may be used as a pressurizing mechanism. Alternatively, instead of at least one of the first vacuum ejector 91 and the second vacuum ejector 92, a pump identical to the suction pump may be connected to the valve section 84e or the valve section 85e.

[0165] (4. Postscript) The content described in the above embodiments is understood as follows. [1] That is to say, A cleaning system 1 for a painting robot 10, wherein the painting robot 10 paints the areas to be painted on a vehicle, and the cleaning system 1 includes: A coating head unit 30 having an inkjet coating head 33, wherein the coating head 33 is arranged with a plurality of nozzles 33 that eject paint droplets; Robotic arm R1, which has a painting head unit 30 mounted at its front end, and moves the painting head unit 30 to the desired position; A cap 93 that closes at least a portion of the nozzle forming surface 32, wherein the nozzle 33 is exposed on the nozzle forming surface 32; The cap moving mechanism 94 moves the cap 93 relative to the nozzle forming surface 32 to achieve a closed state of the nozzle forming surface 32. Return flow path 53, which is connected to the paint discharge side of the coating head 31, recovers the paint or cleaning fluid at least towards the paint tank 57, which is separate from the robot arm R1; A suction mechanism (suction pump 62) is provided in the middle of the return flow path 53 to at least suction the paint that was not sprayed out from the nozzle 33 when the paint was sprayed out. A pressurizing mechanism (outlet pump 64) pressurizes the cleaning fluid supplied toward the coating head 31 in one of the paint supply path 52 and the return flow path 53. A cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) suctions the cleaning fluid discharged from the coating head 31 in another of the paint supply path 52 and return flow path 53; and The control mechanism (main control unit 10, cleaning control unit 150) controls the operation of the pressurization mechanism (export pump 64) and the cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95). When cleaning with cleaning fluid, after the control mechanism (main control unit 10, cleaning control unit 150) operates the cap moving mechanism 94 and the nozzle forming surface 32 is closed by the cap 93, the cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) and the pressurizing mechanism (discharge pump 64) work together. This increases the discharge speed of the cleaning fluid compared to the case where only the pressurizing mechanism (discharge pump 64) is operated.

[0166] In this way, in the inkjet coating head 31 using the coating robot 10, by operating the cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, and vacuum ejector 95) in addition to the pressurizing mechanism (feed pump 64), the discharge performance of the cleaning fluid can be improved compared to the case where only the pressurizing mechanism (feed pump 64) is operated. Therefore, even if the return flow path 53 and the paint supply path 52 become longer, the decrease in the cleanability of the paint circulation path 51 and the increase in cleaning time can be suppressed.

[0167] In particular, when cleaning fluid is supplied via valve sections 84b and 84c of the fourth switching valve 84 and discharged via valve sections 85a and 85e of the fifth switching valve 85, the fluid does not pass through the suction pump 62 in the return flow path 53. Therefore, the suction force of the suction pump 62 cannot be utilized. Consequently, the discharge of cleaning fluid into the drain tank 65 becomes dependent on the delivery pressure of the cleaning fluid from the delivery pump 64, resulting in reduced cleaning performance and increased cleaning time, especially in cases where the return flow path 53 is relatively long.

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

[0169] Furthermore, by sealing the nozzle forming surface 32 with the cap 93, leakage of cleaning fluid from the nozzle 33 to the outside can be prevented, thus enabling cleaning to be performed under a specified pressure within the internal flow path 36. This allows for an increase in the supply pressure of the cleaning fluid within the internal flow path 36, enabling effective cleaning of both the internal flow path 36 and the nozzle 33, and relieving any blockages in these areas.

[0170] [2] Furthermore, in the above embodiments, based on the content described in [1] above, it is preferable that... The coating head 31 has multiple internal flow paths 36 for supplying paint or cleaning fluid to the nozzles 33. The control mechanism (main control unit 110, cleaning control unit 150) activates the cap moving mechanism 94 to adjust the tight contact state of the cap 93 relative to the nozzle forming surface 32. The operation of the cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) is controlled so that the negative pressure change caused by the operation of the cleaning suction mechanism (first vacuum ejector 91, second vacuum ejector 92, vacuum ejector 95) makes the ratio between the amount of cleaning fluid flowing in the internal flow path 36 ejected from the nozzle 33 and the amount that does not eject from the nozzle 33 but passes through the internal flow path 36 variable.

[0171] By activating the cap moving mechanism 94, the cap 93 is adjusted to maintain a tight contact with the nozzle forming surface 32, thereby enabling the cleaning fluid to leak from the nozzle 33 at a predetermined level. In this state of leakage, if negative pressure changes occur due to the operation of the cleaning suction mechanisms (first vacuum ejector 91, second vacuum ejector 92, and vacuum ejector 95), the amount of cleaning fluid leaking from the nozzle 33 can be adjusted to an appropriate proportion. Therefore, even if foreign matter can be directly discharged from the nozzle 33 using the cleaning fluid, this situation can be addressed by adjusting the amount of cleaning fluid ejected from the nozzle 33.

[0172] [3] Furthermore, in the above embodiments, based on the contents described in [1] and [2], or combinations thereof, it is preferable that... The first cleaning suction mechanism (first vacuum ejector 91), corresponding to the cleaning suction mechanism, is connected to the paint supply path 52. The second cleaning suction mechanism (second vacuum ejector 92), corresponding to the cleaning suction mechanism, is connected to the return flow path 53. The control mechanism (main control unit 110, cleaning control unit 150) is configured as follows: During forward cleaning, in which the cleaning fluid flows from the paint supply path 52 to the return flow path 53, the second cleaning suction mechanism (the second vacuum ejector 92) is activated to draw the cleaning fluid back into the return flow path 53. During reverse cleaning, in which the cleaning fluid flows from the return flow path 53 to the paint supply path 52, the first cleaning suction mechanism (first vacuum ejector 91) is activated to draw the cleaning fluid from the paint supply path 52.

[0173] In this way, the control mechanism (main control unit 110, cleaning control unit 150) can effectively achieve forward cleaning by activating the first cleaning suction mechanism (first vacuum ejector 91). Furthermore, the control mechanism (main control unit 110, cleaning control unit 150) can effectively achieve reverse cleaning by activating the second cleaning suction mechanism (second vacuum ejector 92). Thus, by performing both forward and reverse cleaning, the removal of foreign matter from the paint supply path 52, return flow path 53, components located in these flow paths (removal filter 58 and degassing module 59), the internal flow path 36 of the coating head 31, and the nozzle 33, etc., can be improved. Therefore, the cleaning performance at these various locations can be enhanced.

[0174] [4] Furthermore, in the above embodiments, based on the content described in [3] above, it is preferable that... When the control mechanism (main control unit 110, cleaning control unit 150) performs at least one cleaning action in forward cleaning and reverse cleaning, it causes the cap moving mechanism 94 to work, causing the closing pressure of the nozzle forming surface 32 generated by the cap 93 to change, or causing the closed state of the nozzle forming surface 32 generated by the cap 93 to close again after opening.

[0175] By activating the cap moving mechanism 94, the closing pressure of the nozzle forming surface 32 caused by the cap 93 changes. This allows, for example, cleaning fluid to leak out from the nozzle 33, improving the removal of foreign matter present in the internal flow path 36 and the nozzle 33, and thus improving cleaning performance. Furthermore, by opening the closed state of the nozzle forming surface 32 caused by the cap 93, the direction of the cleaning fluid and air flow in the internal flow path 36 and the nozzle 33 within the coating head 31 can be significantly altered, thereby improving the removal of foreign matter present in the internal flow path 36 and the nozzle 33, and further improving cleaning performance.

[0176] [5] Furthermore, in the above embodiments, based on the content described in [3] above, it is preferable that... The first and second cleaning suction mechanisms use the same vacuum ejector 95.

[0177] With this configuration, there is no need to install two vacuum jets, thus simplifying the configuration and reducing the cost of manufacturing the cleaning system 1.

Claims

1. A cleaning system for a painting robot, wherein the painting robot paints the painting areas of a vehicle, the cleaning system being characterized by comprising: A coating head unit having an inkjet coating head, wherein the coating head is arranged with multiple nozzles that spray paint. A robotic arm, which has the coating head unit mounted at its front end, and moves the coating head unit to a desired position; A cap that closes at least a portion of the nozzle forming surface, wherein the nozzle is exposed on the nozzle forming surface; A cap moving mechanism that moves the nozzle forming surface relative to the cap to achieve a closed state of the nozzle forming surface; A paint supply path that supplies the paint or cleaning fluid toward the coating head; The return flow path is connected to the paint discharge side of the coating head, and the paint or the cleaning fluid is recovered at least towards a paint tank that is separate from the robotic arm; A pressurizing mechanism that pressurizes the cleaning fluid supplied toward the coating head in one of the paint supply path and the return flow path; A cleaning suction mechanism that draws the cleaning fluid discharged from the coating head in another of the paint supply path and the return flow path; and The control mechanism controls the operation of the pressurization mechanism and the cleaning suction mechanism. When cleaning with the cleaning fluid, after the control mechanism operates the cap moving mechanism and the cap closes the nozzle forming surface, it also operates the cleaning suction mechanism and the pressurizing mechanism together, thereby increasing the discharge speed of the cleaning fluid compared to the case where only the pressurizing mechanism operates.

2. The cleaning system for the painting robot according to claim 1, characterized in that, The coating head has multiple internal flow paths for supplying the coating material or the cleaning fluid to the nozzle. The control mechanism activates the cap moving mechanism to adjust the tight contact state of the cap relative to the nozzle forming surface. The control mechanism controls the operation of the cleaning suction mechanism, causing a change in negative pressure due to the operation of the cleaning suction mechanism, thereby making the ratio between the amount of cleaning fluid flowing in the internal flow path that is ejected from the nozzle and the amount that does not eject from the nozzle but passes through the internal flow path variable.

3. The cleaning system for the painting robot according to claim 1, characterized in that, A first cleaning suction mechanism, corresponding to the cleaning suction mechanism, is connected to the paint supply line. A second cleaning suction mechanism, corresponding to the cleaning suction mechanism, is connected to the return flow path. During forward cleaning, in which the cleaning fluid flows from the paint supply path to the return flow path, the control mechanism activates the second cleaning suction mechanism to attract the cleaning fluid from the return flow path. During reverse cleaning, in which the cleaning fluid flows from the return flow path to the paint supply path, the control mechanism activates the first cleaning suction mechanism to attract the cleaning fluid from the paint supply path.

4. The cleaning system for the painting robot according to claim 3, characterized in that, When performing at least one of the forward cleaning and reverse cleaning actions, the control mechanism causes the cap moving mechanism to operate, causing the closing pressure of the nozzle forming surface generated by the cap to change, or to close again after opening the closed state of the nozzle forming surface achieved by the cap.

5. The cleaning system for the painting robot according to claim 3, characterized in that, The first cleaning suction mechanism and the second cleaning suction mechanism use the same vacuum jet.

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