Robot for painting car bodies

Abstract

A robot for body painting is provided, which keeps the pressure of paint flowing in a circulation passage of a paint supply device and the pressure of paint present inside a painting head within a proper pressure range by suppressing the posture change of a multi-axis arm as much as possible. The robot for body painting includes a painting head, a storage portion that stores paint, a supply device that can control the pressure of paint flowing in a circulation passage provided between the painting head and the storage portion, and an arm having the painting head and the supply device, the arm being a multi-axis arm that includes a plurality of arm members and movable shaft portions that link the arm members to each other. The robot has a posture control unit that controls the postures of the plurality of arm members to keep the relative position of the painting head and the supply device fixed or suppress the change in the relative position within a prescribed allowable range when the painting head is painting a body, and a moving mechanism that moves the multi-axis arm in a painting direction when the painting head is painting the body.

Description

Technical Field

[0001] This invention relates to a robot for painting car bodies equipped with a painting head having multiple nozzles for spraying paint. Background Technology

[0002] The technology of painting car bodies using painting robots equipped with painting heads having multiple nozzles for discharging paint is becoming increasingly common. Such painting robots typically have a multi-axis arm with multiple arm components and movable shafts connecting these components. A painting head and a paint supply device for supplying paint to the painting head are mounted on the leading arm component (see, for example, Patent Document 1). The paint supply device includes, for example, a container for storing paint, a supply passage for supplying paint to the painting head, and a return passage for returning paint not used by the painting head to the container, with the paint circulating between the container and the painting head. This paint supply device includes a supply pump that delivers paint to the supply passage and a suction pump that draws paint into the return passage. The supply pump and suction pump are controlled based on detection results from detection units such as pressure sensors located in the supply passage and return passage. This control allows not only the pressure of the paint flowing in the supply passage and return passage to be maintained within an appropriate pressure range, but also the pressure of the paint present in the painting head to be maintained within an appropriate pressure range.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2021 / 040005 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the painting of a car body using the aforementioned painting robot, the posture of the multi-axis arm—that is, the posture of each of the multiple arm components constituting the multi-axis arm—changes as the painting head's position relative to the car body changes. When the paint supply device is located on one of the multiple arm components constituting the multi-axis arm, the posture (tilt) of the paint supply device relative to the painting head also changes when the posture of the multi-axis arm changes. Therefore, even if the pressure of the paint flowing in the supply and return paths is controlled within the paint supply device, it is difficult to maintain the pressure of the paint present inside the painting head within an appropriate range. Although it is possible, for example, to detect the paint pressure inside the painting head and control the supply pump and suction pump of the paint supply device based on the detection results, complex control is required to maintain these pressures at an appropriate level.

[0008] The present invention was made to solve the problems described above, and aims to provide a technology that, by suppressing the attitude changes of the multi-axis arm, can maintain the pressure of the paint flowing in the supply passage and return passage of the paint supply device within an appropriate pressure range, and can also maintain the pressure of the paint inside the coating head within an appropriate pressure range.

[0009] Methods for solving problems

[0010] To address the aforementioned issues, the present invention provides a car body painting robot comprising: a painting head capable of spraying paint toward a car body; a supply device having a circulation path for circulating the paint between a storage section storing the paint and the painting head, and capable of controlling the pressure of the paint flowing in the circulation path; and an arm having the painting head and the supply device, wherein the arm is a multi-axis arm having multiple arm components and movable shafts connecting the arm components to each other. The car body painting robot further comprises: a posture control unit that, when painting the car body based on the painting head, controls the posture of the multiple arm components constituting the multi-axis arm, maintaining the relative position between the painting head and the supply device as fixed, or suppressing changes in the relative position within a predetermined permissible range; and a movement mechanism that, when painting the car body based on the painting head, moves the multi-axis arm along the painting direction of the car body in the painting head.

[0011] Furthermore, the aforementioned circulation path includes: a supply path that supplies the paint stored in the storage section to the coating head; and a return path that returns the paint not used by the coating head to the storage section. The supply device includes: a delivery unit that delivers the paint stored in the container to the supply path; a suction unit that suctions the paint from the coating head into the return path; a first detection unit that detects the pressure of the paint delivered to the supply path; a second detection unit that detects the pressure of the paint suctioned into the return path; and a pressure control unit that controls the amount of paint delivered by the delivery unit based on the detection result of the first detection unit, and controls the amount of paint suctioned by the suction unit based on the detection result of the second detection unit.

[0012] In this case, it is preferable that the attitude control unit controls the attitude of the plurality of arm components constituting the multi-axis arm based on the detection results from the first detection unit and the second detection unit.

[0013] In addition, the arm has a base that supports a plurality of arm components connected via the movable shaft in a manner that allows them to rotate freely in two axial directions. The moving mechanism has a guide member that extends along the painting direction of the painting head and a drive unit that moves the base along the guide member. The guide member is located on the floor of the painting chamber where the vehicle body is painted.

[0014] In addition, the arm has a base that supports a plurality of arm components connected via the movable shaft in a manner that allows them to rotate freely in two axial directions. The moving mechanism has a guide member that extends along the painting direction of the painting head and a drive unit that moves the base along the guide member. The guide member is located on the side of the painting chamber where the vehicle body is painted or above the vehicle body being painted.

[0015] Invention Effects

[0016] According to the present invention, by suppressing the attitude change of the multi-axis arm, it is possible not only to maintain the pressure of the paint flowing in the supply passage and return passage of the paint supply device within an appropriate pressure range, but also to maintain the pressure of the paint present inside the coating head within an appropriate pressure range. Attached Figure Description

[0017] Figure 1 This is a top view showing the structure of the robot for painting a car body, which implements the present invention.

[0018] Figure 2 yes Figure 1 The image shown is an observation of a robot used for car body painting from the upstream side of the painting production line.

[0019] Figure 3 yes Figure 1 The image shown is a view of the robot used for car body painting, viewed from the side of the car body.

[0020] Figure 4 This is a diagram illustrating an example of the structure of a paint circulation device.

[0021] Figure 5 This is a diagram illustrating an example of the structure of a control system.

[0022] Figure 6 This is a diagram illustrating an example of the movement trajectory of the painting head on a painting robot.

[0023] Figure 7 In the diagram, (a) shows the pressure change of the paint on the input side of the coating head 56 when the second rotating arm 23 of the robotic arm 15 is set to a horizontal state and coating is performed, and (b) shows the pressure change of the paint on the output side of the coating head 56.

[0024] Figure 8 In the diagram, (a) shows the pressure change of the paint on the input side of the coating head 56 when the posture of the second rotating arm 23 of the robotic arm 15 is changed to perform coating, and (b) shows the pressure change of the paint on the output side of the coating head 56.

[0025] Figure 9 This diagram illustrates an example where the painting robot is not placed on the floor of the painting booth, but rather on the side wall or ceiling of the painting booth, above the vehicle body.

[0026] Explanation of reference numerals in the attached figures

[0027] 10…Painting Robot (Automotive Body Painting Robot)

[0028] 15…robotic arm

[0029] 16…mobile devices

[0030] 21…base (base)

[0031] 22…First rotating arm

[0032] 23…Second Rotating Arm

[0033] 33…Drive mechanism (drive unit)

[0034] 55… Coating Containers (Storage Section)

[0035] 56…Painting Head

[0036] 57…supply channels

[0037] 58…Return Flow Path (Return Flow Path)

[0038] 62… Gear pump (discharge unit)

[0039] 69… Pressure gauge (Detection Unit 1)

[0040] 79… Pressure gauge (Second detection unit)

[0041] 80… Gear pump (suction unit)

[0042] 102…Arm Control Unit (Attitude Control Unit)

[0043] 103… Coating Supply Control Department (Pressure Control Unit) Detailed Implementation

[0044] Hereinafter, a car body painting robot 10 according to the present invention will be described based on the accompanying drawings. Hereinafter, the car body painting robot 10 will be referred to as the painting robot 10. The painting robot 10 of this embodiment is, for example, disposed to the side of a painting production line in an automobile manufacturing plant, and paints car bodies FR transported along the painting production line.

[0045] It should be noted that in this embodiment, the object to be painted by the painting robot 10 (hereinafter referred to as the painting object) is the car body FR, which is described as an example. However, the painting object can also be, for example, a car part other than the car body (for example, car doors, engine hoods, various panels, etc. can be listed, but it is not limited to these). In addition, it can also be various parts other than cars (for example, the exterior parts of airplanes or railways). As long as it is a part that needs to be painted, it is not limited to the car body.

[0046] Painting is the process of forming a coating film on the surface of an object to protect and beautify it. Therefore, painting, in addition to using paint of a specific color or paint with a specific function, also includes painting an object with multiple colors of paint in sequence. Furthermore, painting includes, for example, the painting of patterns, illustrations, or images.

[0047] like Figures 1 to 3 As shown, the painting robot 10, as an example, includes a robotic arm 15, a moving device 16, and a painting head unit 17. Here, the moving device 16 corresponds to the moving mechanism described in the claims. The robotic arm 15 consists of a base 21 and multiple (in...) Figure 1 The structure consists of two arm components 22 and 23, forming a multi-axis arm. The base 21 has a fixed portion 24 fixed to the movable stage 31 (described later) and a rotating portion 25 capable of rotating relative to the fixed portion 24. Here, the base 21 corresponds to the base described in the claims. The fixed portion 24 internally houses a motor M1 (see...). Figure 5 The rotating part 25 is driven by the motor M1 in a direction perpendicular to the ground of the painting production line. Figure 2 or Figure 3 Rotate with the center of rotation in the z-direction or -z-direction.

[0048] Hereinafter, among the multiple arm components 22 and 23, the arm component 22 connected to the rotating part 25 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.

[0049] One end of the first rotating arm 22 in its extending direction is connected to a movable shaft portion 26 provided on the rotating part 25. A motor M2 (see reference 26) is provided on the movable shaft portion 26 of the rotating part 25. Figure 5), so that the connected first rotating arm 22 is in a plane orthogonal to the ground of the painting production line (e.g., when the robotic arm 15 is in position). Figure 2 When in the state of rotation, it rotates on the yz plane.

[0050] In the extending direction of the first rotating arm 22, at the other end opposite to one end connected to the movable shaft 26 of the rotating part 25, a second rotating arm 23 is connected via a movable shaft 27. A motor M3 (described later) is provided on the movable shaft 27. Figure 5 This ensures that the connected second rotating arm 23 is positioned in a plane orthogonal to the ground of the painting production line (e.g., when the robotic arm 15 is in a certain position). Figure 2 When in the state of rotation, it rotates on the yz plane. It should be noted that, although the diagram is omitted, the central axis of the movable shaft 26 of the rotating part 25 is parallel to the central axis of the movable shaft 27 of the first rotating arm 22. It should also be noted that the paint circulation device 51, described later, is provided inside the second rotating arm 23.

[0051] A wrist 28 is provided at the other end of the second rotating arm 23 in the extension direction. The wrist 28 holds the painting head unit 17. Although details about the structure are omitted, the wrist 28 has multiple (three in this case) motors M4, M5, and M6 (see reference) with different axial directions of the drive shafts. Figure 5 By driving one of these motors, the coating head unit 17 is rotated around one of the multiple shafts of the wrist 28 as the rotation center. It should be noted that the number of shafts only needs to be two or more.

[0052] The moving device 16 is positioned on the floor of, for example, a painting room, so that the robotic arm 15 moves along the floor of the painting room in one direction (in... Figure 1 or Figure 3 The robot arm 15 moves back and forth in the x-direction (or -x-direction). It should be noted that the direction of movement of the robot arm 15, implemented based on the moving device 16, becomes the coating direction (main scanning direction) of the coating head 56, described later. The moving device 16 has a moving stage 31 for fixing the base 21 of the robot arm 15, a guide rail 32 for guiding the movement of the moving stage 31, and a drive mechanism 33 for reciprocating the moving stage 31 along the guide rail 32. The guide rail 32 is defined by a frame (omitted in the figure), for example, along the extension direction of the guide rail 32. Figure 1 It is fixed to the floor of the painting chamber in either the x-direction or the -x-direction. Here, the guide rail 32 corresponds to the guide component described in the claims.

[0053] The drive mechanism 33 is fixed to the floor of, for example, a painting room by means of a frame omitted from the illustration. As an example, the drive mechanism 33 is driven by a drive motor 110 (see reference). Figure 5The drive mechanism 33 consists of a drive sprocket 41, a driven sprocket 42, and a drive belt 43 wound around these sprockets 41 and 42. Here, the drive mechanism 33 corresponds to the drive unit described in the claims. Although figures are omitted, the drive sprocket 41 and the driven sprocket 42 are each composed of, for example, two circular plates with multiple teeth formed on their outer circumferential surfaces and a drive shaft that coaxially holds these circular plates. It should be noted that the drive sprocket 41 and the driven sprocket 42 run along the floor of the painting chamber (in... Figure 1 In this configuration, the rotation centers of these sprockets are arranged along the y-direction and the -y-direction. As an example, the drive belt 43 has: two chain belts wound around the two circular plates of the drive-side sprocket 41 and the driven-side sprocket 42 respectively; and multiple connecting rods arranged transversely at multiple positions relative to the two chain belts wound around the drive-side sprocket 41 and the driven-side sprocket 42 respectively. It should be noted that a rubber ring belt may also be used instead of chain belts.

[0054] Therefore, the drive belt 43, which is wound on the drive side sprocket 41 and the driven side sprocket 42, moves towards... Figure 3 It travels in the x-direction or -x-direction. As described above, a moving stage 31 is fixed on the drive belt 43; therefore, if the drive belt 43 travels in the x-direction... Figure 3 If the moving platform 31 travels in the x-direction or -x-direction, it will move along the extension direction of the guide rail 32. Figure 3 Move in the x-direction or -x-direction.

[0055] The painting head unit 17 includes a painting head 56 (described later) and a head control unit for controlling the operation of the painting head 56 (see reference). Figure 5 )wait.

[0056] Next, the paint circulation device 51 will be described. For example... Figure 4 As shown, the paint circulation device 51 has, for example, a supply passage 57 for supplying paint stored in the paint container 55 to the coating head 56, and a return flow path (return flow path) 58 for returning paint not used by the coating head 56 from the coating head 56 back to the paint container 55. In addition, it has a bypass flow path 59 for not supplying paint to the coating head 56, allowing it to flow from the supply passage 57 to the return flow path 58. Furthermore, the paint circulation device 51 places the paint container 55, gear pumps 62 and 80 on the floor of the coating chamber. Additionally, components such as a removal filter 63, a degassing module 64, a switching valve, a proportional valve, and a pressure gauge are housed, for example, inside the second rotating arm 23. Here, the paint circulation device 51 corresponds to the supply device described in the claims. The paint container 55 corresponds to the storage unit described in the claims. It should be noted that a structure in which the gear pumps 62 and 80 are housed, for example, inside the second rotating arm 23 is also possible. Alternatively, a structure can be adopted in which at least one of the components such as the filter 63, degassing module 64, switching valve, proportional valve, and pressure gauge is placed on the ground.

[0057] During the painting of the vehicle body FR, the paint circulation device 51 supplies paint stored in the paint container 55 to the painting head 56, and returns paint not used by the painting head 56 back to the paint container 55, thereby circulating the paint between the paint container 55 and the painting head 56. Furthermore, when the vehicle body FR is not being painted, the paint circulation device 51 causes the paint stored in the paint container 55 to flow back to the paint container 55 in the order of supply passage 57, bypass flow path 59, and return flow path 58.

[0058] Furthermore, the paint used in painting the FR body is, for example, a water-based paint or a solvent-based paint that uses pigments. Therefore, by using the paint circulation device 51 to circulate the paint, the separation and aggregation of pigments contained in the paint are prevented.

[0059] In describing the structure of the supply passage 57 of the paint circulation device 51, the paint container 55 side is designated as the upstream side and the coating head 56 side as the downstream side in the paint supply direction. Similarly, in describing the structure of the return flow path 58 of the paint circulation device 51, the coating head 56 side is designated as the upstream side and the paint container 55 side as the downstream side.

[0060] Paint container 55 stores paint used during the painting of the vehicle body FR by paint head 56. Paint container 55 is located, for example, outside the painting robot 10 (e.g., on the floor of the painting room). Furthermore, during the painting of the vehicle body FR using paint head 56, paint is supplied to paint container 55 from the outside as needed. Additionally, when paint returns to paint container 55 from return flow path 58, air bubbles flowing in with the paint may rise to the surface of the liquid inside paint container 55; paint container 55 may also have the function of removing these air bubbles.

[0061] The painting head 56 has a nozzle forming surface 56a with a plurality of nozzles 61 arranged in a two-dimensional pattern. By spraying paint supplied via the supply passage 57 from each of the plurality of nozzles 61, a coating film is formed on the surface of the vehicle body FR. Further details of the painting head 56 are omitted.

[0062] The supply passage 57 is the path through which paint stored in the paint container 55 is supplied toward the coating head 56. The supply passage 57 has flow paths 57a, 57b, ..., 57h, 57i, which will be described later. In addition, a gear pump 62, a degassing filter 63, and a degassing module 64 are arranged sequentially from the upstream side of the supply passage 57.

[0063] Gear pump 62 draws in paint stored in paint container 55 and delivers the drawn-in paint toward coating head 56. Therefore, when gear pump 62 is driven, the internal pressure of the flow paths 57a and 57b upstream of gear pump 62, i.e., between paint container 55 and gear pump 62, becomes negative, and the paint stored in paint container 55 is drawn into flow paths 57a and 57b. Then, the paint is delivered from gear pump 62 to flow path 57c connected to the downstream side of gear pump 62. Here, gear pump 62 corresponds to the delivery unit described in the claims.

[0064] The flow paths 57a and 57b constituting the supply passage 57 are connected by a three-way valve 66. The three-way valve 66 can be switched between two states: one where flow path 57a is connected to flow path 57b, and the other where flow path 57b is connected to the drainage passage connected to the drainage tank 83. For example, when painting the FR body, the three-way valve 66 remains in the state where flow path 57a and flow path 57b are connected. In addition, when cleaning the supply passage 57, the three-way valve 66 becomes the state where flow path 57b is connected to the drainage tank 83 (specifically, a flow path connected to the drainage tank 83, not shown).

[0065] In the supply passage 57, the gear pump 62 is connected to the flow path 57c on the output side. A switching valve 67 is provided at the downstream end of the flow path 57c. The switching valve 67 has four valve sections 67a, 67b, 67c, and 67d. For example, valve section 67a is connected to the flow path 57c, and valve section 67b is connected to the flow path 57d leading to the removal filter 63. In addition, valve section 67c is connected to the cleaning container 82 (specifically, a flow path not shown connected to the cleaning container 82). Moreover, valve section 67d is connected to the drain tank 83 (specifically, a flow path not shown connected to the drain tank 83). Valve sections 67a and 67b are normally kept in the open state. On the other hand, valve sections 67c and 67d are normally kept in the closed state, and are switched from the closed state to the open state during the cleaning of the paint circulation device 51.

[0066] Downstream of the flow path 57d, which is connected to the valve section 67b of the switching valve 67, a removal filter 63 is provided. The removal filter 63 removes not only coarse foreign matter and pigment agglomerates contained in the paint, but also air bubbles exceeding a specified size contained in the paint. The removal filter 63 is, for example, a mesh-like or porous material such as a metal mesh or resin mesh, or a metal plate with tiny through-holes. Examples of mesh-like materials include metal mesh filters, structures in which metal fibers such as SUS are formed into a felt-like structure, sintered metal filters obtained by compression sintering, electroformed metal filters, electron beam processed metal filters, and laser beam processed metal filters.

[0067] A switching valve 68 is provided downstream of the flow path 57e, which is connected to the output side of the filter 63. Like the switching valve 67, the switching valve 68 has four valve sections 68a, 68b, 68c, and 68d. For example, valve section 68a is connected to the flow path 57e, and valve section 68b is connected to the flow path 57f leading to the degassing module 64. Valve section 68c is connected to the cleaning container 82 (specifically, a flow path not shown connected to the cleaning container 82). Valve section 68d is connected to the drain trough 83 (specifically, a flow path not shown connected to the drain trough 83). Valve sections 68a and 68b are normally kept open. On the other hand, valve sections 68c and 68d are normally kept closed, switching from closed to open during cleaning of the paint circulation device 51.

[0068] A degassing module 64 is provided downstream of the flow path 57f, which is connected to the valve section 68b of the switching valve. The degassing module 64 removes dissolved gases and bubbles dissolved in the coating (degassing). Examples of degassing modules 64 include hollow fiber membrane bundles obtained by bundling multiple hollow fiber membranes together.

[0069] A pressure gauge 69 is provided on the flow path 57g connected to the output side of the degassing module 64. The pressure gauge 69 measures the pressure of the coating material delivered from the degassing module 64. The measurement result of the pressure gauge 69 is output to the coating supply control unit 103 (see reference). Figure 5 The gear pump 62 is driven and controlled by the paint supply control unit 103 so that the pressure value detected by the pressure gauge 69 becomes a fixed value. It should be noted that the pressure gauge 69 corresponds to the first detection unit described in the claims. Additionally, the supply passage 57 may also include one or more pressure gauges other than the pressure gauge 69.

[0070] A switching valve 70 is provided at the downstream end of the aforementioned flow path 57g. Like switching valves 67 and 68, switching valve 70 has four valve sections 70a, 70b, 70c, and 70d. For example, valve section 70a is connected to flow path 57g, and valve section 70b is connected to flow path 57h. Valve section 70c is connected to the cleaning container 82 (specifically, a flow path not shown connected to the cleaning container 82). Valve section 70d is connected to the drain trough 83 (specifically, a flow path not shown connected to the drain trough 83). Valve sections 70a and 70b are normally kept in the open state. On the other hand, valve sections 70c and 70d are normally kept in the closed state, switching from the closed state to the open state during cleaning by the paint circulation device 51.

[0071] A proportional valve 71 is connected to the downstream end of the flow path 57h, which is connected to the valve section 70b of the switching valve. The proportional valve 71 is opened and closed by the paint supply control unit 103 so that the pressure value of the paint flowing downstream of the proportional valve 71 is fixed.

[0072] A flow path 57i is provided downstream of the proportional valve 71. A pressure gauge 72 and a check valve 73 are provided on the flow path 57i. The pressure gauge 72 measures the pressure of the paint flowing from the proportional valve 71 toward the coating head 56. The check valve 73 directs the paint flow in one direction (in this case, from the proportional valve 71 toward the coating head 56) and prevents flow in the opposite direction. Furthermore, the upstream end of a bypass flow path 59 is connected between the pressure gauge 72 and the check valve 73 on the flow path 57i.

[0073] Return flow path 58 is a flow path that allows paint not used by the paint head 56 during the painting of the vehicle body FR, or paint circulated via the bypass flow path 59, to return to the paint container 55. Return flow path 58 has flow paths 58a, 58b, 58c, 58d, and 58e.

[0074] A coating head 56 is connected to the upstream end of flow path 58a. A one-way valve 75 and a pressure gauge 76 are provided on flow path 58a. The one-way valve 75 directs the paint flow in one direction (in this case, from the coating head 56 towards the pressure gauge 76) and prevents flow in the opposite direction. Furthermore, the downstream end of bypass flow path 59 is connected between the one-way valve 75 and the pressure gauge 76 on flow path 58a. The pressure gauge 76 measures the pressure of the paint upstream of proportional valve 77 (i.e., flowing from the coating head 56 towards proportional valve 77).

[0075] A proportional valve 77 is provided on the downstream side of flow path 58a. The proportional valve 77 is opened and closed by the paint supply control unit 103, and the pressure value of the paint flowing from the coating head 56 toward the proportional valve 77 is kept constant.

[0076] A switching valve 78 is provided downstream of flow path 58b, which is connected to the output side of proportional valve 77. Similar to the switching valves 67, 68, and 70 provided in supply passage 57, switching valve 78 has four valve sections 78a, 78b, 78c, and 78d. For example, valve section 78a is connected to flow path 58b, and valve section 78b is connected to flow path 58c leading to gear pump 80. Valve section 78c is connected to cleaning container 82 (specifically, a flow path not shown connected to cleaning container 82). Valve section 78d is connected to drain tank 83 (specifically, a flow path not shown connected to drain tank 83). Valve sections 78a and 78b are normally kept open. On the other hand, valve sections 78c and 78d are normally kept closed, switching from closed to open during cleaning of paint circulation device 51.

[0077] A pressure gauge 79 is provided on the flow path 58c. The pressure gauge 79 measures the pressure of the paint flowing into the flow path 58c. The measurement result of the pressure gauge 79 is output to the paint supply control unit 103. It should be noted that the pressure gauge 79 is equivalent to the second detection unit described in the claims.

[0078] A gear pump 80 is provided at the downstream end of flow path 58c. The gear pump 80 draws paint into flow path 58c and delivers the drawn-in paint towards paint container 55. Therefore, by driving the gear pump 80, the internal pressure of flow path 58c upstream of the gear pump 80 becomes negative, and paint is drawn into flow path 58c. Furthermore, the paint is delivered from the gear pump 80 to flow path 58d, which is connected to the downstream side of the gear pump 80. At this time, the gear pump 80 is driven and controlled by the paint supply control unit 103 so that the pressure value detected by pressure gauge 79 becomes a fixed value. Here, the gear pump 80 corresponds to the suction unit described in the claims.

[0079] A three-way valve 81 is connected downstream of flow path 58d, which is connected to the output side of gear pump 80. The three-way valve 81 can switch between two states: one connecting flow path 58d to flow path 58e connected to paint container 55, and the other connecting flow path 58d to drain tank 83. When the paint head 56 is painting the vehicle body FR or during paint circulation, the three-way valve 81 remains in the state connecting flow path 58d to flow path 58e. However, during cleaning, the three-way valve 81 switches from the state connecting flow path 58d to flow path 58e to the state connecting flow path 58d to drain tank 83. Thus, cleaning fluid and air flowing in flow path 58d are discharged to drain tank 83 via the three-way valve 81.

[0080] The bypass flow path 59 is connected to flow paths 57i and 58a, and when paint application based on the paint head 56 is not performed, a portion of the paint flowing in the supply passage 57 flows to the return flow path 58 instead of the paint head 56. A control valve 84 is provided on the bypass flow path 59. The control valve 84 remains closed when the paint head 56 is applying paint to the vehicle body FR, and switches to the open state when the paint head 56 is not applying paint to the vehicle body FR.

[0081] Next, the structure (hereinafter referred to as the control system) controlling the painting robot 10 described above will be explained. Figure 5 It is a diagram showing the structure of a control system. For example... Figure 5As shown, the control system 100 includes a main control unit 101, an arm control unit 102, a paint supply control unit 103, a head control unit 104, and a moving stage control unit 105. Although not shown in the figure, the main control unit 101, arm control unit 102, paint supply control unit 103, head control unit 104, and moving stage control unit 105 are composed of a CPU (Central Processing Unit), storage units (ROM (Read Only Memory), RAM (Random Access Memory), non-volatile memory, etc.), and other elements.

[0082] The main control unit 101 sends predetermined control signals to the arm control unit 102, the paint supply control unit 103, the head control unit 104, and the moving table control unit 105, so that the robotic arm 15, the moving device 16, the paint circulation device 51, and the painting head 56 cooperate to perform painting on the object to be painted.

[0083] The arm control unit 102 performs drive control on the motors M1, M2, M3, M4, M5, and M6 mounted on the robotic arm 15 based on various data stored in its own arm memory 106. Here, the various data stored in the arm memory 106 are data required by the painting robot 10 when painting the car body FR, such as data on the shape of the car body FR being painted, trajectory data indicating the movement trajectory of the painting head unit 17 during painting, and attitude data indicating the attitude of the robotic arm 15 and the painting head unit 17. Here, the arm control unit 102 corresponds to the attitude control unit described in the claims.

[0084] Here, regarding the painting of the vehicle body FR using the painting robot 10 shown in this embodiment, the painting is performed while maintaining the extension direction of the second rotating arm 23 within the horizontal plane, that is, maintaining the second rotating arm 23 in a horizontal state. Therefore, the above-mentioned posture data includes not only, for example, the posture data of the first rotating arm 22 (rotation amount of motor M1 and motor M2) when the second rotating arm 23 is maintained in a horizontal state, but also the posture data of the second rotating arm 23 relative to the first rotating arm 22 (rotation amount of motor M3).

[0085] Furthermore, when painting multiple car bodies FR with different shapes using the painting robot 10, the aforementioned data and the multiple car bodies FR with different shapes are respectively stored in the arm memory 106.

[0086] Based on the measurement results of pressure gauges 69, 72, 76, and 79 installed in the aforementioned paint circulation device 51, the paint supply control unit 103 performs drive control of gear pumps 62 and 80 and opening / closing control of proportional valves 71 and 77, so that the paint stored in the paint container 55 of the paint circulation device 51 circulates between the paint container 55 and the coating head 56. Here, the paint supply control unit 103 is equivalent to the pressure control unit described in the claims.

[0087] The head control unit 104 operates the piezoelectric substrate 108 based on the position information of the coating head 56 detected by the position sensor 107. Here, the head control unit 104 not only controls the operation of the piezoelectric substrate 108, but also controls the operating frequency of the piezoelectric substrate 108, controls the voltage applied to the piezoelectric substrate 108, and can also control the amount of paint droplets ejected from each of the plurality of nozzles 61 provided on the nozzle forming surface 56a of the coating head 56.

[0088] The position sensor 107 detects the position of the painting head 56, which moves under the control of the arm control unit 102, and outputs its detection signal to the main control unit 101.

[0089] The mobile station control unit 105 controls the operation of the drive motor 110 of the aforementioned mobile device 16, causing the drive-side sprocket 41 to rotate, thereby causing the drive belts 43 wound around the drive-side sprocket 41 and the driven-side sprocket 42 to travel at a desired speed. Through the travel of the drive belts 43, the mobile station 31 fixed to the drive belts 43 moves... Figure 1 It can move in the x-direction or -x-direction. In addition, when the tilting device 111 is provided, the moving stage control unit 105 controls the operation of the tilting device 111 in addition to the moving device 16.

[0090] Position sensor 112 detects the position of the mobile station 31, which moves under the control of the mobile station control unit 105, and outputs its detection signal to the main control unit 101 via the mobile station control unit 105.

[0091] The tilting device 111 is a device that tilts the moving device 16. Although not shown in the figure, the tilting device 111 can be, for example, a cylinder that extends and retracts the cylinder rod relative to the cylinder body by means of air supply, or a device using multiple gears and cams. It should be noted that the tilting device 111 may not be configured to be driven and controlled by the moving stage control unit 105, but may be operated manually or by an external drive unit when the moving device 16 is installed, by adjusting, for example, the feed screw mechanism.

[0092] Next, the control during the painting of the vehicle body FR using painting robot 10 will be explained. It should be noted that... Figure 6This illustrates an example of the movement trajectory of the paint head 56 during the painting of a vehicle body TR. For example... Figure 6 As shown, when the painting robot 10 is not painting the FR of the car body, the painting head 56 remains in, for example, a standby position. Figure 6 (Position P1 is shown in the middle). If painting begins based on the painting robot 10, the moving table control unit 105 drives the drive motor 110. Driven by the drive motor 110, the drive belt 43 wound on the drive-side sprocket 41 and the driven-side sprocket 42 moves, and the moving table 31 moves towards... Figure 6 The mobile station 31 moves in the x-direction. Figure 6 The robotic arm 15, fixed on the moving platform 31, moves in the x-direction. Figure 6 The robot arm 15, i.e., the painting head 56, moves from position P1 to position P2 at a speed of 300 mm / s, for example.

[0093] At this time, as an example of control, there is a situation where the arm control unit 102 prevents any of the motors M1, M2, M3, M4, M5, and M6 from being driven. In this case, the moving stage 31 moves towards... Figure 6 When moving in the x-direction, the postures of the first rotating arm 22 and the second rotating arm 23 of the robotic arm 15 remain fixed.

[0094] If via mobile station 31 to Figure 6 When the painting head 56 moves to position P2 in the x-direction, the moving stage control unit 105 stops driving the drive motor 110.

[0095] If the drive motor 110 is stopped, the arm control unit 102 drives motors M2 and M3 to move the coating head 56 from position P2 to position P3. At this time, the arm control unit 102 drives motors M2 and M3 to keep the second rotating arm 23 in a horizontal state. Furthermore, if the coating head 56 moves to position P3, the arm control unit 102 stops the drive of motors M2 and M3. Here, the moving speed of the robotic arm 15, i.e., the coating head 56, from position P2 to position P3 is, for example, 300 mm / s.

[0096] If the coating head 56 moves to position P3, the moving table control unit 105 drives the drive motor 110, causing the moving table 31 and the robotic arm 15 fixed on the moving table 31 to move towards... Figure 6 The painting head 56 moves from position P3 to position P4. Here, the moving speed of the robotic arm 15, i.e., the painting head 56, from position P3 to position P4 is, for example, 300 mm / s.

[0097] Here, during the painting of the vehicle body FR by the paint head 56, between position P4 and position P5... Figure 6The paint head 56 moves back and forth in the -x direction or x direction. During the movement from position P4 to position P5 and from position P5 to position P4, painting is performed using multiple nozzles 61 provided on the nozzle forming surface 56a of the paint head 56 (hereinafter, the painting of all nozzles using multiple nozzles provided on the nozzle forming surface 56a is referred to as one line of painting). After one line of painting is completed, the paint head 56 is moved one line in the -y direction. Therefore, the area between position P4 and position P5 becomes the painting area painted by the paint head 56. Furthermore, in the painting of the vehicle body FR based on the paint head 56, the moving speed of the paint head 56 is set to, for example, in the range of 30 mm / s to 200 mm / s.

[0098] After the painting head 56 reaches position P4, the arm control unit 102 drives the motors M4, M5, and M6 with reference to the body shape data stored in the arm memory 106. At the same time, the moving table control unit 105 drives the tilting device 111.

[0099] Therefore, the wrist 28 and the painting head 56 are aligned. Figure 6 The painting head 56 rotates together with the movement in the x-direction. Additionally, driven by the tilting device 111, the painting head 56 rotates in the vertical direction ( Figure 1 The paint head 56 moves in the z-direction (or -z-direction). Therefore, the nozzle forming surface 56a of the paint head 56 is maintained at a fixed interval relative to the painting area of ​​the vehicle body FR. At this time, the second rotating arm 23 remains horizontal. Therefore, when the wrist 28 is not rotating, the relative position of the paint circulation device 51 and the paint head 56 remains unchanged. Furthermore, when the paint head 56 moves due to the rotation of the wrist 28, the relative position of the paint circulation device 51 and the paint head 56 changes within a predetermined range based on the rotation of the wrist 28. In this state, the head control unit 104 activates the piezoelectric substrate 108.

[0100] If the coating head 56 moves to position P5, the coating of one row based on the coating head 56 is completed. Therefore, the moving table control unit 105 stops driving the drive motor 110. At the same time, the arm control unit 102 drives motors M2 and M3 (and motor M1 if necessary) to change the posture of the robotic arm 15. As a result, the coating head 56 moves towards... Figure 6 Move one row in the -y direction.

[0101] The mobile stage control unit 105 drives the drive motor 110, causing the mobile stage 31 and the robotic arm 15 fixed to the mobile stage 31 to move towards... Figure 6The painting head 56 moves in the x-direction. As a result, the painting head 56 moves from position P5 to position P4. At this time, the head control unit 104 activates the piezoelectric substrate 108. Thus, painting of the vehicle body FR is performed based on the painting head 56. In this case, the arm control unit 102 drives the motors M4, M5, and M6 of the wrist 28 fixed to the second rotating arm 23, changing the posture of the painting head 56, maintaining a fixed distance between the nozzle forming surface 56a of the painting head 56 and the painting area of ​​the vehicle body FR. Furthermore, when the painting head 56 reaches position P4, the moving stage control unit 105 stops driving the motor 110. Thus, the next row of paint is applied to the vehicle body FR.

[0102] During the painting of the FR body, the action of moving the painting head 56 from position P4 to position P5 (or vice versa) and then moving it one row in the -y direction is performed multiple times. Furthermore, if the entire FR body has been painted and the head has moved to position P5, the arm control unit 102 drives motors M2, M3, M4, M5, and M6 to move the painting head from position P5 to position P1.

[0103] It should be noted that when the coating head 56 moves, the pressure of the coating flowing in the supply passage 57 and the return flow path 58 is controlled based on the detection results of the pressure gauge 69 on the supply passage 57 of the coating circulation device 51 and the detection results of the pressure gauge 79 on the return flow path 58. In addition, the opening and closing control of the proportional valve 71 based on the pressure gauge 72 and the opening and closing control of the proportional valve 77 based on the pressure gauge 76 are also performed.

[0104] Furthermore, in this embodiment, the moving speed of the coating head 56 is reduced when the coating head 56 reaches position P4. However, the position at which the moving speed of the coating head 56 is reduced is not limited to position P4; it can also be reduced when, for example, it reaches position P2.

[0105] Next, consider the changes (variations) in the internal pressure of the paint circulation device 51 based on the state of the second rotating arm 23 when painting the vehicle body FR using the painting robot 10 described above.

[0106] Figure 7 (a) is a graph showing the pressure change of the paint on the input side of the coating head 56 when coating is performed with the second rotating arm 23 of the robotic arm 15 in a horizontal position. Additionally, Figure 7 (b) is a graph showing the pressure change of the paint on the output side of the coating head 56 when the second rotating arm 23 of the robotic arm 15 is in a horizontal position and coating is performed. Additionally, Figure 8(a) is a diagram showing the pressure change of the paint on the input side of the paint head 56 during painting when the posture of the second rotating arm 23 of the robotic arm 15 is changed. Additionally, Figure 8 (b) is a graph showing the pressure change of the paint on the output side of the coating head 56 during coating when the posture of the second rotating arm 23 of the robotic arm 15 is changed. These graphs show the measurement results when the coating head moves from position P4 to position P5. It should be noted that the target value for the paint pressure on the input side of the coating head 56 is set to, for example, 0.1 bar, and the target value for the paint pressure on the output side of the coating head 56 is set to, for example, -0.1 bar.

[0107] like Figure 7 of (a), Figure 7 As shown in (b), when coating is performed with the second rotating arm 23 in a horizontal position, the pressure of the paint flowing toward the coating head 56 on the input side varies within the range of 0.09 bar to 0.1075 bar. That is, it can be seen that the pressure of the paint flowing toward the coating head 56 varies around the target value, ensuring a stable supply of paint toward the coating head 56. Furthermore, the pressure of the paint discharged from the coating head 56 on the output side varies within the range of -0.0925 bar to -0.1075 bar. That is, it can be seen that the pressure of the paint discharged from the coating head 56 varies around the target value, ensuring a stable discharge of paint from the coating head 56.

[0108] On the other hand, such as Figure 8 (a) and Figure 8 As shown in (b), when coating is performed by tilting the second rotating arm 23 so that the coating head 56 is positioned downwards, the pressure of the paint flowing toward the coating head 56 on the input side varies from 0.093 bar to 0.106 bar. That is, it is known that the pressure of the paint flowing toward the coating head 56 varies around the target value, ensuring a stable flow of paint toward the coating head 56. However, the pressure of the paint discharged from the coating head 56 on the output side varies from -0.078 bar to -0.0975 bar. That is, it is known that the pressure of the paint discharged from the coating head 56 varies by a value deviating from the target value, failing to ensure a stable discharge of paint from the coating head 56.

[0109] Based on these results, it can be seen that when painting is performed with the second rotating arm 23 in a horizontal position, the influence of the head difference between the painting head 56 and the paint circulation device 51 is smaller compared to the case where painting is performed with the second rotating arm 23 tilted, thus enabling stable paint circulation. That is, in the painting robot 10, when painting the vehicle body FR based on the painting head 56, it is desirable to keep the second rotating arm 23 in a horizontal position. Only when it is difficult to keep the second rotating arm 23 in a horizontal position is the second rotating arm 23 tilted at a predetermined angle. Therefore, by suppressing the influence of the head difference between the painting head 56 and the paint circulation device 51, the pressure of the paint flowing in the supply passage 57 and return flow path 58 of the paint circulation device 51 can be stabilized, that is, the paint can be stably circulated between the paint container 55 and the painting head 56.

[0110] In this embodiment, the case where the moving device 16 is placed on the floor of the painting room is described, but it is not limited to this and can be used in various ways. Figure 9 As shown, for example, the moving device 16 is installed on the side wall or ceiling of the painting chamber, above the vehicle body FR, which is the object to be painted. Therefore, since it is no longer necessary to arrange the elements required for painting on the ground, a painting chamber with a reduced floor area can be provided for painting the vehicle body FR.

[0111] In this embodiment, by performing coating based on the coating head 56 while keeping the second rotating arm 23 of the robotic arm 15 in a horizontal state, the generation and variation of the head difference between the paint circulation device 51 and the coating head 56 are suppressed. For example, in the case of coating objects such as engine hoods and roofs on the vehicle body FR, which have coating surfaces with height differences, it is necessary to rotate the first rotating arm 22 and the second rotating arm 23 of the robotic arm 15 in order to move the coating head 56 up and down. There are also cases where it is difficult to keep the second rotating arm 23 in a horizontal state through these rotations. To deal with such a situation, for example, a lifting device for raising and lowering the rotating part 25 can be provided on the base 21 of the robotic arm 15, and the second rotating arm 23 can be kept in a horizontal state by raising and lowering the rotating part 25 relative to the fixed part 24.

[0112] Furthermore, in cases where there are painting objects with varying heights, such as engine hoods and roofs located on the front wing of a vehicle body, painting can be performed using different painting robots depending on the painting area by setting up painting robots for painting engine hoods and painting robots for painting roofs. This allows painting to be performed while keeping the second rotating arm in a horizontal position during the painting action performed by each painting robot.

[0113] Furthermore, when the painting head 56 moves along the shape of the vehicle roof or engine hood, there is also a possibility that the first rotating arm 22 and the second rotating arm 23 of the painting robot 10 will rotate. In such cases, although the painting head 56 moves towards... Figure 1 The coating head 56 can be moved slightly in the z-direction or -z-direction, but this will not cause pressure fluctuations. Furthermore, when the coating head 56 is moved rapidly or moved up and down over a large range, the pressure of the coating material will fluctuate due to the abrupt changes in the posture of the first rotating arm 22 and the second rotating arm 23 of the coating robot 10. However, in this embodiment, since the posture of the first rotating arm 22 and the second rotating arm 23 of the coating robot 10 remains fixed, pressure fluctuations accompanying changes in the posture of these arms can be prevented.

[0114] In this embodiment, the arm control unit 102 controls the posture of the second rotating arm 23 in the robotic arm 15 based on the shape data of the vehicle body FR stored in the arm memory 106. However, the arm control unit 102 can also use pressure values ​​measured by pressure gauges 69 and 79 provided in the paint circulation device 51 in addition to the shape data of the vehicle body FR to maintain the posture of the second rotating arm 23 in a horizontal state. In this case, the arm control unit 102 drives motors M2 and M3 to maintain the second rotating arm 23 in a horizontal state, so that the pressure values ​​measured by pressure gauges 69 and 79 are fixed or the pressure value fluctuations are within a specified range.

[0115] (Regarding the results)

[0116] The painting robot 10 of the present invention includes: a painting head 56 capable of spraying paint toward a vehicle body FR; a paint circulation device 51 having a supply passage 57 and a return flow path 58 for circulating paint between a paint container 55 storing paint and the painting head 56, and capable of controlling the pressure of the paint flowing in the supply passage 57 and the return flow path 58; and a robotic arm 15 having the painting head 56 and gear pumps 62 and 80. In the painting robot 10, the robotic arm 15 includes a first rotating arm 22 and a second rotating arm 23 and these arms are interconnected. The multi-axis arm with movable shafts 26 and 27 of the joint, the painting robot 10 has: an arm control unit 102, which controls the posture of the first rotating arm 22 and the second rotating arm 23 constituting the multi-axis arm when painting the car body FR based on the painting head 56, and keeps the relative position of the painting head 56 and the paint circulation device 51 fixed or suppresses the change of the relative position within a specified allowable range; and a moving device 16, which moves the multi-axis arm along the painting direction of the car body FR in the painting head 56 when painting the car body FR based on the painting head 56.

[0117] In the absence of a moving device, for example, the base of the multi-axis arm is fixed in a predetermined position. At this time, when the coating position of the coating head is close to the base of the multi-axis arm, the arm components constituting the multi-axis arm are in an upright state; conversely, when the coating position of the coating head is far from the base of the multi-axis arm, the arm components are in a horizontal state. That is, when the base of the multi-axis arm is fixed, the pressure control of the paint flowing in the circulation path requires consideration not only of the movement of the multi-axis arm but also of the head difference between the supply device and the coating head, making the pressure control of the paint flowing in the circulation path complex.

[0118] On the other hand, in this invention, the relative position of the coating head 56 and the paint circulation device 51 is kept fixed, or any variation in the relative position is suppressed within a specified allowable range. Therefore, in the pressure control of the paint flowing in the supply passage 57 and the return flow path 58, the influence of the head difference between the paint circulation device 51 and the coating head 56 can be significantly reduced, thus facilitating pressure control of the paint in the supply passage 57 and the return flow path 58.

[0119] Additionally, the supply passage 57 supplies paint stored in the paint container 55 to the coating head 56, and the return flow path 58 returns paint not used by the coating head 56 back to the paint container 55. It includes: a gear pump 62 that delivers paint stored in the paint container 55 to the supply passage 57; a gear pump 80 that draws paint from the coating head 56 into the return flow path 58; a pressure gauge 69 that detects the pressure of the paint delivered to the supply passage 57; a pressure gauge 79 that detects the pressure of the paint drawn into the return flow path 58; and a paint supply control unit 103 that controls the amount of paint delivered by the gear pump 62 based on the detection result of the pressure gauge 69, and controls the amount of paint drawn into the gear pump 80 based on the detection result of the pressure gauge 79.

[0120] According to this structure, when painting the vehicle body FR based on the painting head 56, the gear pumps 62 and 80 can be controlled based on the pressure of the paint fed into the supply passage 57 of the paint circulation device 51 and the pressure of the paint sucked into the return flow path 58, so that the pressure of the paint in each flow path can be maintained at an appropriate pressure.

[0121] In addition, the arm control unit 102 controls the posture of the first rotating arm 22 and the second rotating arm 23 of the robotic arm 15 based on the detection results from the pressure gauges 69 and 79.

[0122] For example, in the paint circulation device 51, the pressure of the paint supplied to the painting head 56 and the pressure of the paint returning to the paint container 55 are controlled based on the detection results of pressure gauges 69 and 79. For example, the pressure values ​​detected by pressure gauges 69 and 79 change based on the posture changes of the robotic arm 15. Therefore, even if sensors such as height detection sensors are not installed in the paint circulation device 51 and the painting head 56, the arm control unit 102 can maintain the paint circulation device 51 and the painting head 56 at the same height in the height direction of the vehicle body FR, or suppress the variation within a specified allowable height range, by utilizing the detection results of these detection units.

[0123] Additionally, the robotic arm 15 has a base 21, which supports the first rotating arm 22 and the second rotating arm 23 connected via movable shafts 26 and 27 in a manner that allows them to rotate freely in two axial directions. The moving device 16 has a guide rail 32 extending along the painting direction of the painting head 56 on the vehicle body FR; and a drive-side sprocket 41, a driven-side sprocket 42, a drive belt 43, and a drive motor 110 that move the base 21 along the guide rail 32. The guide rail 32 is located on the floor of the painting chamber where the vehicle body FR is painted.

[0124] Thus, with the painting head 56 and the paint circulation device 51 always at the same height, the robotic arm 15 can move in coordination with the painting head 56 to the painting position of the vehicle body FR.

[0125] Additionally, the robotic arm 15 has a base 21, which supports the first rotating arm 22 and the second rotating arm 23 connected via movable shafts 26 and 27 in a manner that allows them to rotate freely in two axial directions. The moving device 16 has a guide rail 32 extending along the painting direction of the painting head 56 on the vehicle body FR; and a drive-side sprocket 41, a driven-side sprocket 42, a drive belt 43, and a drive motor 110 for moving the base 21 along the guide rail 32. The guide rail 32 is located on the side of the painting chamber where the vehicle body FR is painted or above the vehicle body being painted.

[0126] Therefore, the robotic arm 15 can move in coordination with the painting head 56 to paint the vehicle body FR while the painting head 56 and the paint circulation device 51 are always kept at the same height. In addition, by providing the guide rail 32 on the side of the painting chamber or above the vehicle body FR to be painted, it is not necessary to arrange the elements required for painting on the floor of the painting chamber. Therefore, a painting chamber with a reduced floor area can be provided when painting the vehicle body FR.

Claims

1. A robot for vehicle body painting, characterized by comprising: have: The paint sprayer head is capable of spraying paint onto the vehicle body; A supply device having a circulation path for circulating the paint between a storage section for storing the paint and a coating head, and capable of controlling the pressure of the paint flowing in the circulation path; and An arm having the coating head and the supply device, The arm is a multi-axis arm having multiple arm components and a movable shaft connecting the arm components to each other. The plurality of arm components include a rotating arm that is part of the supply device, and a wrist portion that holds the coating head at one end of the rotating arm. The wrist portion rotates the coating head about one of a plurality of shaft portions. The robot for car body painting has the following features: A moving mechanism that, when painting the vehicle body based on the painting head, moves the multi-axis arm along the painting direction of the vehicle body in the painting head; and The attitude control unit drives and controls the multi-axis arm, the wrist, and the movement mechanism. When painting the vehicle body using the painting head, the attitude control unit controls the attitude of the multi-axis arm and drives the moving mechanism. By maintaining the rotating arm in a horizontal position and moving the multi-axis arm along the painting direction of the vehicle body, the relative position between the painting head and a portion of the supply device located on the rotating arm is kept fixed. Alternatively, by driving the wrist to rotate the painting head while maintaining the rotating arm in a horizontal position and moving the multi-axis arm along the painting direction of the vehicle body, the variation in the relative position is suppressed within a specified allowable range. The circulation path includes: a supply path that supplies the paint stored in the storage section to the coating head; and a return path that returns the paint not used by the coating head to the storage section. The supply device has: The delivery unit delivers the paint stored in the storage section to the supply passage; A suction unit that draws the coating material from the coating head into the return flow path; The first detection unit detects the pressure of the coating material fed into the supply passage; The second detection unit detects the pressure of the coating material drawn into the return flow path; and The pressure control unit controls the amount of coating delivered by the delivery unit based on the detection result of the first detection unit, and controls the amount of coating drawn in by the suction unit based on the detection result of the second detection unit. The attitude control unit controls the attitude of the plurality of arm components constituting the multi-axis arm based on the detection results from the first detection unit and the second detection unit.

2. The robot for car body painting according to claim 1, characterized in that, The arm has a base that supports the plurality of arm components connected via the movable shaft in a manner that allows them to rotate freely in two axial directions. The moving mechanism has: A guide component extending along the coating direction of the coating head; and A drive unit that moves the base along the guide member. The guide component is located on the floor of the paint booth where the vehicle body is painted.

3. The robot for painting a vehicle body according to claim 1, characterized in that, the arm has a base portion that rotatably supports the plurality of arm portions connected via the movable shaft portion, the moving mechanism has: a guide member that extends in a painting direction of the painting head; and a drive unit that moves the base portion along the guide member, the guide member is provided at a position on a side of a painting chamber in which the vehicle body is painted or above the vehicle body being painted.

Images