Robot for painting vehicle bodies

Abstract

A robot for painting a vehicle body that suppresses deterioration of painting quality of a painting head by suppressing pressure variation and vibration of a multi-axis arm that occurs when the multi-axis arm is operated. A painting device of the invention has: a painting head that sprays paint toward a vehicle body; a supply device that has a circulation path that circulates paint between a storage portion that stores the paint and the painting head, and that is capable of controlling the pressure of the paint that flows in the circulation path; an arm portion that has the painting head and the supply device, and that moves the painting head in a main scanning direction by operation of the arm portion while painting the vehicle body, the robot for painting the vehicle body having a control mechanism that controls the operation of the arm portion, the painting head being moved toward a painting start position at which painting of the vehicle body is started by the operation of the arm portion at a first speed, and being moved at a second speed that is different from the first speed when a specific position that is provided in a movement path up to the painting start position is reached.

Description

Technical Field

[0001] This invention relates to a robot for painting car bodies equipped with a painting head, wherein the painting head has a plurality of nozzles for spraying paint. Background Technology

[0002] The technology of painting automobile bodies using painting robots equipped with painting heads having multiple nozzles for spraying paint is now widespread. Such painting robots are configured as multi-axis arms comprising, for example, multiple arm components and movable shafts connecting the arm components to each other. A painting head and a 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 unused paint from the painting head to the container, with the paint circulating between the container and the painting head. Furthermore, the 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; these pumps are controlled based on detection results from detection mechanisms installed in the supply passage and the return passage. As a result, when the painting robot operates, the pressure of the paint flowing in the supply passage and the return passage can be maintained at an appropriate level.

[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] The painting head moves back and forth multiple times in the main scanning direction via the multi-axis arm of the painting robot. Additionally, each time movement occurs in the main scanning direction, a predetermined amount is moved in the secondary scanning direction. During this multi-axis arm movement, the pressure of the paint flowing in the paint supply device is prone to variation due to acceleration at the start of the movement, deceleration upon stopping, and the vibration of the multi-axis arm itself. This pressure variation causes instability in the paint supply to the painting head, resulting in deviations in the amount of paint sprayed from the multiple nozzles within the painting head. Furthermore, the vibration of the multi-axis arm itself causes irregularities in the landing position of the paint sprayed from the multiple nozzles within the painting head. For these reasons, the painting quality deteriorates during vehicle body painting using this painting head.

[0008] This invention was developed to solve the aforementioned problems, and its purpose is to provide a car body painting robot that can suppress the deterioration of the painting quality of the painting head by suppressing pressure changes and vibrations of the multi-axis arm generated during the movement of the multi-axis arm of the painting robot.

[0009] Methods for solving problems

[0010] To address the aforementioned issues, the present invention provides a robot for painting a car body, comprising: a painting head that sprays paint toward a car body; a supply device having a circulation path that circulates 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. The robot paints the car body while moving the painting head in a main scanning direction via the movement of the arm. The robot has a control mechanism that controls the movement of the arm. The painting head moves toward a painting start position at a first speed based on the movement of the arm according to the control mechanism, and upon reaching a specific position within the movement path up to the painting start position, moves at a second speed different from the first speed.

[0011] In addition, the second speed is set to be lower than the first speed, or the first speed is set to be lower than the second speed.

[0012] In addition, when the painting head reaches the painting start position, it begins painting the vehicle body while maintaining the second speed.

[0013] In addition, the coating head reciprocates multiple times in the main scanning direction, and when switching to reciprocate in the main scanning direction, it moves a predetermined amount in the secondary scanning direction orthogonal to the main scanning direction. The coating start position is respectively set in the path and loop of the reciprocate movement in the main scanning direction.

[0014] In addition, the coating head moves at a third speed, which is lower than the second speed, when it moves a predetermined amount in the sub-scanning direction.

[0015] Furthermore, the vehicle body painting robot of the present invention includes: a painting head that sprays paint toward a vehicle body; a supply device having a circulation path for circulating the paint between a storage section for 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. The vehicle body painting robot performs painting of the vehicle body while moving the painting head in a main scanning direction by the movement of the arm. The vehicle body painting robot has a control mechanism for controlling the movement of the arm. The painting head moves to a painting start position where painting of the vehicle body begins and temporarily stops, and after temporarily stopping at the painting start position and a predetermined time has elapsed, it resumes moving from the painting start position toward the main scanning direction to paint the vehicle body. The moving speed of the painting head during painting of the vehicle body is set to a different moving speed than the moving speed of the painting head up to the painting start position.

[0016] In addition, the coating head reciprocates multiple times in the main scanning direction, and when switching to reciprocate in the main scanning direction, it moves a predetermined amount in the sub-scanning direction orthogonal to the main scanning direction. The coating start position is respectively set in the path and loop of the reciprocate movement in the main scanning direction, and the coating head temporarily stops at the coating start position respectively set in the path and the loop.

[0017] In addition, when the painting head is not painting the vehicle body, it remains in the initial position. The control mechanism controls the movement of the arm based on the start of painting the vehicle body, so that the painting head moves from the initial position to the painting start position.

[0018] Additionally, the circulation path includes: a supply passage that supplies the paint stored in the storage section to the coating head; and a return passage that allows unused paint from the coating head to flow back to the storage section. The supply device includes: a delivery mechanism that delivers the paint stored in the storage section to the supply passage; a suction mechanism that draws the paint from the coating head into the return passage; a first detection mechanism that detects the pressure of the paint delivered into the supply passage; a second detection mechanism that detects the pressure of the paint drawn into the return passage; and a pressure control mechanism that controls the amount of paint delivered by the delivery mechanism based on the detection result of the first detection mechanism, and controls the amount of paint drawn by the suction mechanism based on the detection result of the second detection mechanism.

[0019] Invention Effects

[0020] According to the present invention, a robot for car body painting can be provided that can suppress the deterioration of the painting quality of the painting head by suppressing pressure changes and vibrations of the multi-axis arm generated during the movement of the multi-axis arm. Attached Figure Description

[0021] Figure 1 (a) is a top view showing the configuration of the robot for painting a car body according to the present invention, and (b) is a side view of the robot for painting a car body shown in (a).

[0022] Figure 2 This is a diagram illustrating an example of the configuration of a paint circulation device.

[0023] Figure 3 This is a diagram illustrating an example of the configuration of a control system.

[0024] Figure 4 (a) is a diagram showing an example of the movement trajectory of the coating head on the xy plane, and (b) is a diagram showing an example of the movement trajectory of the coating head on the xz plane.

[0025] Figure 5 This is a diagram illustrating an example of the change in the moving speed of the painting head.

[0026] Figure 6 (a) is a graph showing the displacement of the pressure value on the input side of the paint head when the paint head decelerates at position P2 and performs body painting, and (b) is a graph showing the displacement of the pressure value on the output side of the paint head when the paint head decelerates at position P2 and performs body painting.

[0027] Figure 7 (a) is a graph showing the displacement of the pressure value on the input side of the paint head when the paint head decelerates at position P4 and performs body painting, and (b) is a graph showing the displacement of the pressure value on the output side of the paint head when the paint head decelerates at position P4 and performs body painting.

[0028] Figure 8 This is a diagram showing an example of the moving speed of the painting head between position P4 and position P5.

[0029] Figure 9 (a) is a graph showing the displacement of the pressure value on the input side of the paint head when the paint head is stopped at the paint start position for a specified time before painting the vehicle body, and (b) is a graph showing the displacement of the pressure value on the output side of the paint head when the paint head is stopped at the paint start position for a specified time before painting the vehicle body.

[0030] Explanation of reference numerals in the attached figures

[0031] 10…Painting Robot (Automotive Body Painting Robot)

[0032] 15… Robotic Arm

[0033] 21…base (base)

[0034] 22…First rotating arm

[0035] 23…Second Rotating Arm

[0036] 51…Paint circulation device (supply device)

[0037] 55… Coating Containers (Storage Section)

[0038] 56…Painting Head

[0039] 57…supply channels

[0040] 58…Return Flow Path (Return Flow Path)

[0041] 62… Gear pump (feeding mechanism)

[0042] 69… Pressure gauge (First Testing Agency)

[0043] 79… Pressure gauge (Second Testing Agency)

[0044] 80… Gear pump (suction mechanism)

[0045] 102… Arm Control Unit (Control Mechanism)

[0046] 103… Coating Supply Control Department (Pressure Control Mechanism) Detailed Implementation

[0047] 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, arranged in the lateral direction of a painting line in an automobile manufacturing plant, and paints a car body FR transported along the painting line.

[0048] 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 used as an example. However, the painting object can also be a car part other than the car body (for example, car doors, engine hoods, various panels, etc. can be given, but it is not limited to this). It can be any other part other than a car (for example, the exterior parts of an airplane or railway) that needs to be painted, and it is not necessary to limit it to the car body.

[0049] Painting is the process of forming a coating film on the surface of an object to provide it with protection and aesthetic appeal. Therefore, painting, in addition to using paint of a specific color or paint with a specific function, also includes painting an object using multiple colors of paint sequentially. Furthermore, painting includes, for example, painting patterns, illustrations, or images.

[0050] like Figure 1 (a) and Figure 1 As shown in (b), as an example, the painting robot 10 has a robotic arm 15 and a painting head unit 17. The robotic arm 15 consists of a base 21 and multiple (in) Figure 1 The multi-axis arm consists of two arm components 22 and 23. The base 21 has a fixed part 24 and a rotating part 25 capable of rotating relative to the fixed part 24. Here, the base 21 corresponds to the base described in the technical solution. The fixed part 24 internally houses a motor M1 (see...). Figure 3 The rotating part 25 is driven by the motor M1 and rotates around the center of rotation in a direction perpendicular to the ground of the painting line (hereinafter referred to as the vertical direction).

[0051] 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.

[0052] One end of the first rotating arm 22 in its extending direction is connected to a movable shaft 26 provided in the rotating part 25. A motor M2 (see [reference needed]) is provided in the movable shaft 26 of the rotating part 25. Figure 3 ), so that the connected first rotating arm 22 is in a plane orthogonal to the ground of the painting line (e.g., when the robot arm 15 is located at Figure 1 (b) is a rotation on the yz plane.

[0053] In the extending direction of the first rotating arm 22, the second rotating arm 23 is connected to the other end of the rotating part 25, opposite to the end connected to the movable shaft part 26, via the movable shaft part 27. The movable shaft part 27 is equipped with the electric motor M3 described later (see [link to motor description]). Figure 3 ), so that the connected second rotating arm 23 is in a plane orthogonal to the ground of the painting line (e.g., when the robot arm 15 is located at Figure 1 In state (b), 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 provided on the first rotating arm 22. It should also be noted that, as detailed later, the second rotating arm 23 is internally equipped with a paint circulation device 51, which will be described later.

[0054] A wrist 28 is provided at the other end of the second rotating arm 23 in the extension direction. The wrist 28 holds the coating head unit 17. The wrist 28 has multiple (three in this case) electric motors M4, M5, and M6 with different axial directions of the drive shaft (see... Figure 3 By driving any one of these motors, the held painting head unit 17 can rotate around any one of the multiple shafts of the wrist 28 as a rotation center. It should be noted that the number of shafts can be two or more.

[0055] The painting head unit 17 includes a painting head 56 (described later) and a head control unit for controlling the movement of the painting head 56 (see [link]). Figure 3 )wait.

[0056] As described above, a paint circulation device 51 is provided inside the second rotating arm 23. Figure 2 As shown, the paint circulation device 51, in addition to having 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 unused paint from the coating head 56 to the paint container 55, also has a bypass flow path 59 that does not supply paint to the coating head 56 but flows from the supply passage 57 to the return flow path 58. Here, the paint container 55 corresponds to the storage unit described in the technical solution. Furthermore, the paint circulation device 51 places the paint container 55 and the gear pump 62 on the floor of the coating chamber, and houses components such as the removal filter 63, degassing assembly 64, switching valves 67, 68, 70, 78, proportional valves 71, 77, and pressure gauges 69, 72, 76, 79 inside the second rotating arm 23. Here, the paint circulation device 51 corresponds to the supply device described in the technical solution. It should be noted that the gear pump 62 can also be configured, for example, to be housed inside the second rotating arm 23. Alternatively, it can be configured to have at least one of the following components, such as the removal filter 63, the degassing assembly 64, the switching valve, the proportional valve, and the pressure gauge, placed on the ground.

[0057] The paint circulation device 51 supplies paint stored in the paint container 55 to the painting head 56 during the painting of the vehicle body FR, and returns unused paint from the painting head 56 to the paint container 55, thereby circulating the paint between the paint container 55 and the painting head 56. Additionally, 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 sequentially through the supply passage 57, the bypass flow path 59, and the return flow path 58 before returning to the paint container 55.

[0058] However, the paints used in FR body painting are, for example, water-based paints or solvent-based paints that use 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 the following description of the configuration 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 the description of the configuration 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 when painting the FR body using paint head 56. Paint container 55 is located, for example, outside the painting robot 10 (e.g., on the floor of the painting booth). It should be noted that during the FR painting of the body using paint head 56, paint is supplied to paint container 55 from the outside as needed. Furthermore, when paint returns to paint container 55 from return flow path 58, air bubbles flowing in with the paint may float on the surface of the liquid in 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 the plurality of nozzles 61, a coating film is formed on the surface of the vehicle body FR. It should be noted that the detailed structure of the painting head 56 is omitted.

[0062] The supply passage 57 is the path through which the 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 assembly 64 are sequentially arranged in the middle of the supply passage 57, starting 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 pressure inside 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. It is then delivered from gear pump 62 to flow path 57c, which is connected to the downstream side of gear pump 62. Here, gear pump 62 corresponds to the delivery mechanism described in the technical solution.

[0064] 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 connecting flow path 57a and flow path 57b, and the other connecting flow path 57b to the drainage passage connected to the drainage tank 83. During, for example, FR painting of the vehicle body, the three-way valve 66 remains in the state connecting flow path 57a and flow path 57b. Furthermore, when cleaning the supply passage 57, the three-way valve 66 becomes the state connecting flow path 57b to the drainage tank 83 (specifically, the 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). Furthermore, valve section 67d is connected to the drain trough 83 (specifically, a flow path not shown connected to the drain trough 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, switching from the closed state to the open state during the cleaning of the paint circulation device 51.

[0066] A removal filter 63 is provided downstream of the flow path 57d, which is connected to the valve section 67b of the switching valve 67. The removal filter 63 removes coarse foreign matter, pigment agglomerates, and other foreign matter contained in the paint, as well as air bubbles exceeding a specified size contained in the paint. The removal filter 63 is, for example, a mesh-like material such as a metal mesh or resin mesh, a porous material, or a metal plate with tiny through holes. Examples of mesh-like materials include metal mesh filters, metal fibers such as SUS formed into a felt-like structure, metal sintered filters formed 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 assembly 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 assembly 64 is provided downstream of the flow path 57f, which is connected to the valve section 68b of the switching valve. The degassing assembly 64 removes dissolved gases and bubbles from the coating (degassing). Examples of degassing assemblies 64 include hollow fiber membrane bundles consisting of multiple hollow fiber membranes bundled together.

[0069] A pressure gauge 69 is provided in the flow path 57g connected to the output side of the degassing assembly 64. The pressure gauge 69 measures the pressure of the coating material delivered from the degassing assembly 64. The measurement result of the pressure gauge 69 is output to the coating supply control unit 103 (see...). Figure 3 The gear pump 62 is driven and controlled by the paint supply control unit 103, ensuring that the pressure value detected by the pressure gauge 69 remains constant. It should be noted that the pressure gauge 69 is equivalent to the first detection mechanism described in the technical solution. Additionally, one or more pressure gauges other than the pressure gauge 69 may be provided in the supply passage 57.

[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 open. On the other hand, valve sections 70c and 70d are normally kept closed, switching from closed to open 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 controlled by the paint supply control unit 103 to keep the pressure of the paint flowing downstream of the proportional valve 71 constant.

[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. It should be noted that 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 returns unused paint from paint head 56 during body FR painting or paint circulated via bypass flow path 59 to paint container 55. Return flow path 58 has flow paths 58a, 58b, 58c, 58d, and 58e.

[0074] In flow path 58a, a coating head 56 is connected at the upstream end. A one-way valve 75 and a pressure gauge 76 are provided in 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. It should be noted that a bypass flow path 59 is connected downstream of the one-way valve 75 and the pressure gauge 76 in flow path 58a. The pressure gauge 76 measures the pressure of the paint flowing upstream of the proportional valve 77, i.e., from the coating head 56 towards the 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 to keep the pressure of the paint flowing from the coating head 56 toward the proportional valve 77 constant.

[0076] A switching valve 78 is provided downstream of flow path 58b, which is connected to the output side of proportional valve 77. Switching valve 78, like switching valves 67, 68, and 70 provided in supply passage 57, 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, which leads 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 trough 83 (specifically, a flow path not shown connected to drain trough 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 mechanism described in the technical solution.

[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 pressure upstream of the gear pump 80, i.e., inside flow path 58c, 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 constant value. Here, the gear pump 80 is equivalent to the suction mechanism described in the technical solution.

[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. During FR painting of the vehicle body by painting head 56 or during paint circulation, the three-way valve 81 remains in the state where flow path 58d is connected 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. When paint coating based on the paint head 56 is not being performed, a portion of the paint flowing in the supply passage 57 flows into the return flow path 58 instead of flowing into the paint head 56. A control valve 84 is provided in the bypass flow path 59. The control valve 84 remains closed during body FR painting based on the paint head 56 and switches to the open state when body FR painting based on the paint head 56 is not being performed.

[0081] Next, the configuration of the painting robot 10 described above (hereinafter referred to as the control system) will be explained. Figure 3 This is a diagram showing the configuration of the control system. (For example...) Figure 3As shown, the control system 100 includes a main control unit 101, an arm control unit 102, a paint supply control unit 103, and a head control unit 104. Although not shown in the figure, the main control unit 101, arm control unit 102, paint supply control unit 103, and head control unit 104 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 specified control signals to the arm control unit 102, the paint supply control unit 103 and the head control unit 104 respectively, so that the robot arm 15, the paint circulation device 51 and the painting head 56 work together to perform painting on the object to be painted.

[0083] The arm control unit 102 performs drive control on each of the motors M1, M2, M3, M4, M5, and M6 installed on the robot arm 15 based on various data stored in its own arm memory 106. Here, the various data stored in the arm memory 106 are required for the FR (front-facing) painting of the car body performed by the painting robot 10, and include, for example, data on the shape of the FR car body being painted, trajectory data indicating the movement trajectory of the painting head unit 17 during the FR painting process, and attitude data indicating the attitude of the robot arm 15 and the painting head unit 17. Here, the arm control unit 102 is equivalent to the control mechanism described in the technical solution.

[0084] Here, the painting robot 10 shown in this embodiment is used to perform body FR painting while maintaining the extension direction of the second rotating arm 23 in a horizontal state, that is, while 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 when the second rotating arm 23 is maintained in a horizontal state (rotation amount of motor M1, motor M2), but also the posture data of the second rotating arm 23 relative to the first rotating arm 22 (rotation amount of motor M3).

[0085] It should be noted that when multiple car bodies FR with different shapes are painted by the painting robot 10, the above-mentioned data and the multiple car bodies FR with different shapes are respectively stored in the arm memory 106.

[0086] The paint supply control unit 103 controls the drive of gear pumps 62 and 80 and the opening and closing of proportional valves 71 and 77 based on the measurement results of pressure gauges 69, 72, 76, and 79 installed in the paint circulation device 51, 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 mechanism described in the technical solution.

[0087] The head control unit 104 operates the piezoelectric substrate 109 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 109, but also controls the operating frequency of the piezoelectric substrate 109 and the voltage applied to the piezoelectric substrate 109, and controls 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] Position sensor 107 detects the position of the painting head 56, which moves under the control of arm control unit 102, and outputs its detection signal to main control unit 101. Tilt sensor 108 uses, for example, a gyroscope sensor. Tilt sensor 108 detects the tilt of robot arm 15 and painting head 56, and outputs its detection signal to main control unit 101.

[0089] Next, we will explain an example of control procedures used in FR painting of a car body using painting robot 10. It should be noted that... Figure 4 (a) is a diagram showing an example of the movement trajectory of the paint head 56 on the xy plane during FR painting of the vehicle body. Figure 4 Figure (b) is an example of the movement trajectory of the paint head 56 on the xz plane during FR painting of the vehicle body. Additionally, Figure 5 This is a diagram illustrating an example of the change in the moving speed of the paint head 56 during FR painting of a vehicle body.

[0090] like Figure 4 (a) and Figure 4 As shown in (b), when the painting robot 10 is not performing FR painting on the car body, the painting head 56 remains in, for example, a standby position (in...). Figure 4 (a) shows position P1). When the painting robot 10 starts painting, the arm control unit 102 drives motors M1, M2, M3, M4, M5, and M6. As a result, the first rotating arm 22, the second rotating arm 23, and the wrist 28 of the robot arm 15 move, and the painting head 56 moves from position P1 to position P2. Here, if the movement speed of the painting head 56 from position P1 to position P2 is set as V1, then the movement speed V1 is, for example, V1 = 300 mm / s.

[0091] Then, after the coating head 56 reaches position P2, the arm control unit 102 decelerates the moving speed of the coating head 56, which is driven by motors M1, M2, M3, M4, M5, and M6, and moves the coating head 56 from position P2 to position P3. It should be noted that, as... Figure 4 (a) and Figure 4 As shown in (b), since position P3 is lower than position P2, the coating head 56 moves in the yz plane driven by the robot arm 15. At this time, the coating head 56... Figure 4 Move in the y direction in (a), and then... Figure 4 In (b), move in the -z direction (or vice versa), or, simultaneously, in Figure 4 The movement in the y direction in (a) and in Figure 4 In (b), the movement is in the -z direction. Here, the moving speed V2 of the painting head 56, which moves from position P2 to position P3, is set to, for example, a range of 30 mm / s to 100 mm / s.

[0092] If the coating head 56 reaches position P3, the arm control unit 102 does not change the moving speed of the coating head 56 driven by the motors M1, M2, M3, M4, M5, and M6, and moves the coating head 56 from position P3 to position P4.

[0093] For example, in the FR painting of the car body performed by paint head 56, between position P4 and position P5, Figure 4 The coating head 56 reciprocates in either the -x or x direction. During either the movement from position P4 to position P5 or the movement from position P5 to position P4, coating is performed using the plurality of nozzles 61 provided on the nozzle forming surface 56a of the coating head 56 (hereinafter, the entire coating using the plurality of nozzles 61 provided on the nozzle forming surface 56a is referred to as one line of coating). Once one line of coating is completed, the coating head 56 is moved one line in the -y direction. In other words, the movement of the coating head 56 from position P4 to position P5 corresponds to the movement of the path in the reciprocating movement in the main scanning direction. Furthermore, the movement of the coating head 56 from position P5 to position P4 corresponds to the movement of the loop in the reciprocating movement in the main scanning direction.

[0094] It should be noted that the moving speed of the painting head 56 when it moves from position P4 to position P5 and the moving speed when it moves from position P5 to position P4 are the moving speed V2. In addition, the moving speed of the painting head 56 when it moves one row in the -y direction can be the same as the moving speed V2 from position P2 to position P3, or it can be less than the moving speed V2 mentioned above.

[0095] When the painting head 56 moves between positions P4 and P5, that is, when the painting head 56 moves along its path in the reciprocating movement in the main scanning direction, the arm control unit 102 drives M1, M2, M3, M4, M5, and M6 with reference to the data of the body FR's external shape stored in the arm memory 106. Therefore, the painting head 56 moves along the external shape of the body FR at predetermined intervals relative to the body FR.

[0096] As the painting head 56 moves from position P4 to position P5, it begins pre-painting processing upon passing position P4. When the painting head 56 reaches one end of the vehicle body FR (position P6), paint is sprayed from multiple nozzles 61 provided on the nozzle forming surface 56a of the painting head 56. When the painting head 56 moves and reaches the other end of the vehicle body FR in the main scanning direction (position P7), the spraying of paint from the multiple nozzles 61 provided on the nozzle forming surface 56a of the painting head 56 stops, and processing accompanying the end of painting begins. Upon reaching position P5, the movement of the painting head 56 is completely finished.

[0097] If the coating head 56 moves to position P5, the coating of one row by the coating head 56 is completed. Then, the arm control unit 102 continues to drive the motors M1, M2, M3, M4, M5, and M6, so that the coating head 56... Figure 4 Move one row in the -y direction from the center.

[0098] Then, the arm control unit 102 drives motors M1, M2, M3, M4, M5, and M6 to change the posture of the robot arm 15, causing the coating head 56 to move from position P5 to position P4. It should be noted that the moving speed of the coating head 56 at this time is V2.

[0099] As the painting head 56 moves from position P5 to position P4, pre-painting processing begins. When the painting head 56 reaches the other end of the vehicle body FR (position P7), paint is sprayed from a plurality of nozzles 61 provided on the nozzle forming surface 56a of the painting head 56. Furthermore, when it reaches one end of the vehicle body FR in the main scanning direction (position P6), the spraying of paint from the plurality of nozzles 61 provided on the nozzle forming surface 56a of the painting head 56 stops, and processing accompanying the end of painting begins. When it reaches position P4, the operation of the painting head 56 is completely finished.

[0100] In other words, when the coating head 56 moves along its reciprocating path in the main scanning direction, position P4 becomes the coating start position, and position P5 becomes the coating end position. At this time, paint is ejected from the multiple nozzles 61 of the coating head 56 between positions P6 and P7. Furthermore, when the coating head 56 moves along its reciprocating loop in the main scanning direction, position P5 becomes the coating start position, and position P4 becomes the coating end position. At this time, paint is ejected from the multiple nozzles 61 of the coating head 56 between positions P7 and P6.

[0101] In the FR painting of the vehicle body, after the painting head 56 is moved from position P4 to position P5 (or vice versa), it moves one row in the -y direction multiple times. Then, when the entire FR of the vehicle body is painted and the head moves to position P5, the arm control unit 102 drives the motors M1, M2, M3, M4, M5, and M6 to move the painting head 56 from position P5 to position P1.

[0102] 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 installed in the supply passage 57 of the coating circulation device 51 and the pressure gauge 79 installed in 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 performed.

[0103] Hereinafter, we will consider the pressure supplied to the coating head 56 and the pressure delivered from the coating head 56 when using the coating robot 10 described above.

[0104] Figure 6 (a) is a graph showing the displacement of the pressure on the input side of the paint head 56 when the paint head 56 is decelerated at position P2 and FR painting of the vehicle body is performed. Figure 6 (b) is a diagram showing the displacement of the pressure on the output side of the paint head 56 during body FR painting after the paint head 56 is decelerated at position P2. Additionally, Figure 7 (a) is a graph showing the displacement of the pressure on the input side of the paint head 56 during body FR painting after the paint head 56 is decelerated at position P4. Figure 7 (b) is a graph showing the displacement of the pressure on the output side of the paint head 56 when the paint head 56 is decelerated at position P4 and the body FR is being painted.

[0105] Here, in the vehicle body FR, the pressure of the paint flowing toward the paint head 56 is set to a target value of, for example, 0.1 bar, and the pressure of the paint delivered from the paint head 56 is set to a target value of, for example, -0.1 bar.

[0106] like Figure 6(a) and Figure 6 As shown in (b), when the paint head 56 decelerates at position P2 and performs FR painting on the vehicle body, the pressure of the paint on the input side of the paint head 56 varies from 0.09 bar to 0.11 bar. Additionally, the pressure of the paint on the output side of the paint head 56 varies from -0.1050 bar to -0.0915 bar. It should be noted that these pressure variations are believed to be caused by, for example, changes in the posture of the first rotating arm 22 and / or the second rotating arm 23 of the robot arm 15, or the inertia of the paint caused by the deceleration of the paint head 56.

[0107] On the other hand, such as Figure 7 (a) and Figure 7 As shown in (b), when the paint head 56 performs FR painting on the vehicle body after deceleration at position P4, the pressure of the paint on the input side of the paint head 56 varies between 0.0875 bar and 0.1125 bar. Additionally, the pressure of the paint on the output side of the paint head 56 varies within the range of -0.10875 bar to -0.0875 bar. At this time, for example, after 3 seconds of starting painting, a larger pressure change is observed. Furthermore, in this case, the pressure change is large. The reason for this is believed to be that painting begins in a non-convergent state, such as the inertia of the paint during the rapid deceleration at position P4.

[0108] In other words, it is known that when the coating head 56 decelerates at position P2, the pressure changes of the coating material on both the input and output sides of the coating head 56 during coating are suppressed compared to when it decelerates at position P4. That is, as... Figure 5 As shown, at a position P2 closer to the front of the position P4 where the painting head 56 begins painting preparation, the moving speed of the painting head 56 is reduced, and the moving speed of the painting head 56 is set to the moving speed V2 during FR painting of the vehicle body. For example, when the moving painting head 56 decelerates, the pressure of the paint supplied to the painting head 56 and the pressure of the paint delivered from the painting head 56 change due to the inertia of the paint and the vibration of the robot arm 15. However, by performing such speed control of the painting head 56, the pressure change of the paint accompanying the deceleration of the painting head 56 can be made to converge until the FR painting of the vehicle body begins. As a result, the degradation of the FR painting performance of the vehicle body by the painting head 56 can be avoided, and stable FR painting of the vehicle body can be implemented.

[0109] It should be noted that, in this embodiment, the position at which the coating head 56 decelerates at position P2 is not limited to position P2. It can be, for example, a position where the pressure change associated with the deceleration of the coating head 56 converges during the period until the coating head 56 begins coating.

[0110] Furthermore, in this embodiment, the painting head 56 decelerates at position P2 and maintains its decelerated travel speed while performing FR painting of the vehicle body. For example, the travel speed of the painting head 56 during FR painting is a fixed speed determined by the painting performance of the painting head 56. Therefore, when the painting head 56 passes through position P2, after temporarily decelerating to a speed slower than that of the painting head 56 during FR painting, the travel speed of the painting head 56 can be accelerated to the travel speed of the painting head 56 during FR painting when it reaches, for example, position P3 or position P4. As a result, although the pressure change of the paint during deceleration is large, the pressure change of the paint before and after acceleration and the vibration of the robot arm 15 can be suppressed as much as possible, thereby improving the painting performance.

[0111] Alternatively, the painting head 56 can be accelerated at position P2 (or position P3) instead of decelerating, to achieve the FR painting speed required for the vehicle body. In this case, by accelerating the painting head 56 in stages, the pressure changes of the paint and the vibration of the robot arm 15 during each acceleration can be suppressed.

[0112] In this embodiment, the coating head 56 decelerates at position P2, but may also stop for a predetermined time, for example, at position P4. It should be noted that the predetermined time is the time until the pressure change accompanying the stopping of the coating head 56 converges, and is set to, for example, 5 seconds. It should also be noted that the predetermined time can be set either corresponding to the moving speed of the coating head 56 when it moves from position P1 to position P4, or based on the measurement results of at least one of the pressure gauges 69, 72, 76, and 79 of the paint circulation device 51.

[0113] At this time, as Figure 8 As shown, when the coating head 56 moves along its path in the reciprocating motion of the main scanning direction, the coating head 56 moves from... Figure 4 As shown in (b), when position P4 moves toward position P6, it accelerates at position P6 to the target moving speed (e.g., moving speed V2). Additionally, the painting head 56, upon reaching... Figure 4 The coating head 56 decelerates after position P7 as shown in (b) to stop at position P5. It should be noted that, similarly, when the coating head 56 moves in the loop of reciprocating movement in the main scanning direction, it accelerates as it moves from position P5 toward position P7 to reach the target moving speed at position P7, and decelerates after reaching position P6 to stop at position P5.

[0114] In this case, as the coating head 56 moves along its reciprocating path in the main scanning direction, position P4 becomes the coating start position and position P5 becomes the coating end position. Furthermore, between position P6 and position P7, paint is sprayed from the multiple nozzles 61 of the coating head 56. Additionally, as the coating head 56 moves along its reciprocating loop in the main scanning direction, position P5 becomes the coating start position and position P4 becomes the coating end position. Furthermore, between position P7 and position P6, paint is sprayed from the multiple nozzles 61 of the coating head 56.

[0115] Figure 9 (a) is a graph showing the pressure change on the input side of the paint head 56 when the paint head 56 is stopped at position P4 for 5 seconds before performing FR painting on the vehicle body. Additionally, Figure 9 (b) is a graph showing the pressure change on the output side of the paint head 56 when the paint head 56 is stopped at position P4 for 5 seconds and then FR paint is applied to the vehicle body. It should be noted that, in this case, the target value of the pressure on the input side of the paint head 56 is also set to 0.1 bar, and the target value of the pressure on the output side of the paint head 56 is set to -0.1 bar.

[0116] like Figure 9 As shown in (a), the pressure of the paint on the input side of the coating head 56 varies within the range of 0.0875 bar to 0.1125 bar. Additionally, as... Figure 9 As shown in (b), the pressure of the coating material on the output side of the coating head 56 varies within the range of -0.11 bar to -0.0875 bar. Figure 7 (a) and Figure 7 As shown in (b), when the paint head 56 decelerates and performs FR painting on the vehicle body as it moves from position P1 to position P4, the pressure of the paint on the input side of the paint head 56 varies between 0.0875 bar and 0.1125 bar. Additionally, the pressure of the paint on the output side of the paint head 56 varies within the range of -0.10875 bar to -0.0875 bar.

[0117] When the painting head 56 stops at position P4 for 5 seconds before performing FR painting on the vehicle body, the change in posture of the robot arm 15 due to the movement of the painting head 56 causes a change in paint pressure associated with the change in posture of the robot arm 15 at the start of painting. It is known that, compared to the case where the vehicle body FR painting is performed while decelerating at position P4, the pressure changes of the paint on both the input and output sides of the painting head 56 are suppressed. Therefore, it can be seen that performing FR painting on the vehicle body while moving the painting head 56 at a speed lower than the speed at which it moved to position P4 after it has moved to position P4 is also effective in suppressing the pressure changes within the paint circulation device 51 associated with the movement of the painting head 56.

[0118] It should be noted that the description focused on the case where the painting head 56 moves along the path in the main scanning direction after stopping at position P4 for a predetermined time. However, the same applies to the case where it moves along the loop in the main scanning direction, allowing the painting head 56 to stop at position P5 for a predetermined time. In this case, when switching from movement along the path in the main scanning direction to movement along the loop in the main scanning direction, the painting head 56 moves a predetermined distance in the sub-scanning direction. However, the speed at which the painting head 56 moves in the sub-scanning direction can be either lower or higher than the speed used for painting the FR body of the vehicle. Furthermore, when multiple painting robots 10 are used to paint multiple FR bodies simultaneously, or when multiple painting robots 10 are used to paint a single FR body, the painting heads 56 installed in each robot arm 15 may collide during the driving of each robot arm 15. For example, in order to prevent the painting heads 56 provided in each robot arm 15 from colliding, if there is a collision avoidance position in the movement trajectory of the painting head 56 from the end of the movement of the path in the main scanning direction to the start of the movement of the loop in the main scanning direction (or vice versa), the movement speed of the painting head 56 can be changed before and after the avoidance position.

[0119] In this embodiment, the moving speed of the painting head 56 is reduced before reaching position P4 or temporarily stopped at position P4 to prevent pressure changes associated with the movement of the painting head 56 caused by the robotic arm 15 from affecting the FR painting of the car body performed by the painting head 56. However, in the FR painting of the car body using the painting robot 10, there is also a situation where the first rotating arm 22 and the second rotating arm 23 rotate due to the drive of the robotic arm 15, causing the painting head 56 to vibrate and the landing position of the paint sprayed from the plurality of nozzles 61 provided on the nozzle forming surface 56a of the painting head 56 to deviate. To prevent this phenomenon, a vibration detection mechanism and a vibration application mechanism can be provided in the second rotating arm to eliminate the vibration detected by the mechanism or to apply a vibration with a phase opposite to the phase of the detected vibration to the second rotating arm.

[0120] (Regarding the results)

[0121] The vehicle body painting robot 10 of the present invention includes: a painting head 56 that sprays paint toward the 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 circulation path formed by the supply passage 57 and the return flow path 58; and a robot arm 15 having the painting head 56 and the paint circulation device 51. The vehicle body painting robot 10 performs vehicle body FR painting by moving the painting head 56 in the main scanning direction through the movement of the robot arm 15, and has an arm control unit 102 for controlling the movement of the robot arm 15. The painting head 56 moves toward the painting start position (position P4) where the vehicle body FR painting begins, based on the movement of the robot arm 15 of the arm control unit, at a first speed, and moves at a second speed different from the first speed when it reaches a specific position (position P2) set within the movement path up to the painting start position.

[0122] For example, when no FR painting is being performed on the vehicle body, the painting head 56 remains at a preset initial position (position P1). When a new FR painting is being performed, it moves from the initial position towards the painting start position through the movement of the robotic arm 15. It should be noted that when the robotic arm 15 begins to move, the paint circulation device 51 and the painting head 56, both located within the robotic arm 15, are affected by the acceleration at the start of the robotic arm 15's movement, causing pressure changes in the paint flowing in the supply passage 57 and return flow path 58 of the paint circulation device 51. Additionally, the robotic arm 15 itself also vibrates simultaneously. As a result, the paint supply to the painting head 56 becomes unstable, causing deviations in the amount of paint sprayed from the multiple nozzles 61 provided in the painting head 56. Furthermore, this leads to a disordered landing position of the paint sprayed from the multiple nozzles 61 provided in the painting head 56.

[0123] In this invention, if the coating head 56 moves to a specific position (position P2) within its movement path from the initial position to the coating start position, the moving speed of the coating head 56 is changed to a different speed and it moves to the coating start position. Through this control, the pressure changes of the paint flowing in the paint circulation device 51 and the vibration of the robot arm 15 itself can be reduced during the period until the coating head 56 moves to the coating start position. This stabilizes the paint supply to the coating head 56 and suppresses not only deviations in the amount of paint sprayed from the multiple nozzles 61 provided in the coating head 56, but also irregularities in the landing position of the paint sprayed from the multiple nozzles 61 provided in the coating head 56. As a result, in the FR painting of the vehicle body performed by the coating head 56, the degradation of the painting quality can be prevented.

[0124] It should be noted that by setting the second speed to be lower than the first speed, or setting the first speed to be lower than the second speed, it is possible to prevent the pressure changes of the paint associated with the change in moving speed from affecting the coating process in the coating head 56.

[0125] In addition, when the paint head 56 reaches the paint start position, it begins FR paint application on the vehicle body while maintaining the second speed.

[0126] According to this configuration, the moving speed of the paint head 56 remains constant after passing a specific position. That is, the effect of pressure changes caused by deceleration at the specific position is suppressed at the beginning of the painting process, and the FR painting of the vehicle body can be maintained in this state. As a result, the degradation of the painting quality can be prevented during the FR painting of the vehicle body performed by the paint head 56.

[0127] In addition, the coating head 56 reciprocates multiple times in the main scanning direction, and when switching to reciprocate in the main scanning direction, it moves a predetermined amount in the secondary scanning direction orthogonal to the main scanning direction. The coating start position is set in the path and loop of the reciprocate movement in the main scanning direction.

[0128] Therefore, when switching back and forth in the main scanning direction, it is possible to prevent the vibration caused by pressure changes and posture changes of the robot arm 15 when moving a specified amount in the sub-scanning direction orthogonal to the main scanning direction from affecting the coating process using the coating head 56.

[0129] At this time, the coating head 56 moves at a third speed, which is lower than the second speed, when it moves a predetermined amount in the sub-scanning direction.

[0130] This reduces pressure changes when moving a specified amount in the sub-scanning direction orthogonal to the main scanning direction, thus enabling stable coating using the coating head 56.

[0131] Additionally, the vehicle body painting robot 10 of the present invention includes: a painting head 56 that sprays paint toward the 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 for 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 robot arm 15 having the painting head 56 and the paint circulation device 51. The vehicle body painting robot 10 performs vehicle body FR painting by moving the painting head 56 in the main scanning direction through the movement of the robot arm 15. The device includes an arm control unit 102 that controls the movement of the robotic arm 15. The painting head 56 moves to the painting start position (position P6) where the FR painting of the car body begins, and stops temporarily, based on the control of the robotic arm 15 by the arm control unit 102. After the painting start position is temporarily stopped and a predetermined time has elapsed, it starts moving again from the painting start position towards the main scanning direction to perform FR painting of the car body. The moving speed of the painting head 56 when performing FR painting of the car body is set to a different moving speed than the moving speed of the painting head 56 when it moves to the painting start position.

[0132] For example, when the robot arm 15 begins to move, the paint circulation device 51 and the coating head 56, which are installed on the robot arm 15, are affected by the acceleration at the start of the robot arm 15's movement, causing changes in the pressure of the paint flowing in the supply passage 57 and return flow path 58 of the paint circulation device 51. Additionally, the robot arm 15 itself also vibrates simultaneously. As a result, the paint supply to the coating head 56 becomes unstable, causing deviations in the amount of paint sprayed from the multiple nozzles 61 installed in the coating head 56. Furthermore, the landing positions of the paint sprayed from the multiple nozzles 61 installed in the coating head 56 become disordered.

[0133] In this invention, by temporarily stopping the coating head 56, which has moved from the initial position to the coating start position, at the coating start position, the pressure changes of the paint flowing in the paint circulation device 51 and the vibration of the robot arm 15 itself are reduced. The coating head 56, which has been temporarily stopped at the coating start position, begins coating after a certain period of time. At this time, the coating head 56 moves from the coating start position along the main scanning direction, and its moving speed is set lower than the moving speed of the coating head 56 from the initial position to the coating start position. Therefore, the pressure changes of the paint flowing in the paint circulation device 51 are smaller than the pressure changes when the coating head 56 moves from the initial position towards the coating start position. This stabilizes the paint supply to the coating head 56 and suppresses not only deviations in the amount of paint sprayed from the multiple nozzles 61 provided in the coating head 56, but also irregularities in the landing position of the paint sprayed from the multiple nozzles 61 provided in the coating head 56. As a result, the degradation of paint quality can be suppressed during the FR painting of the vehicle body performed by the paint head 56.

[0134] In addition, the coating head 56 reciprocates multiple times in the main scanning direction, and when switching to reciprocate movement in the main scanning direction, it moves a predetermined amount in the sub-scanning direction orthogonal to the main scanning direction. The coating start position is set in the path and loop of the reciprocate movement in the main scanning direction, and the coating head temporarily stops at the coating start position set in the path and loop, respectively.

[0135] This ensures a stable supply of paint to the paint head 56. Furthermore, it suppresses not only deviations in the amount of paint sprayed from the multiple nozzles 61 in the paint head 56, but also irregularities in the landing position of the paint sprayed from the multiple nozzles 61 in the paint head 56. As a result, in FR painting of the vehicle body performed by the paint head 56, the deterioration of the paint quality can be suppressed.

[0136] In addition, when the painting head 56 is not performing FR painting on the car body, it remains in the initial position. The arm control unit 102 controls the movement of the robot arm 15 based on the start of FR painting on the car body, so that the painting head 56 moves from the initial position to the painting start position.

[0137] According to this configuration, when the body FR is not being painted, the painting head 56 is kept in an initial position away from the body FR, thus preventing the painting head 56 from coming into contact with the painted body or the unpainted body FR.

[0138] Additionally, the paint circulation device 51 includes a supply passage 57 for supplying paint stored in the paint container 55 to the coating head 56 and a return flow path 58 for returning unused paint from the coating head 56 to the paint container 55. The device further 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 into 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 by the gear pump 80 based on the detection result of the pressure gauge 79.

[0139] Therefore, when the robotic arm 15 moves, the gear pumps 62 and 80 can be controlled based on the pressure of the paint in the supply passage 57 of the paint circulation device 51 and the pressure of the paint in the return flow path 58, thus maintaining the pressure of the paint in each flow path at an appropriate level. That is, the paint circulation device 51 can stably supply paint to the coating head 56.

Claims

1. A robot for vehicle body painting, characterized by comprising: include: The paint sprayer head sprays 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; as well as The arm portion has the painting head and the supply device. The robot for painting the car body moves the painting head in the main scanning direction by the movement of its arm while painting the car body. The robot for painting car bodies has a control mechanism for controlling the movement of the arm. The painting head moves at a first speed toward the painting start position where painting of the vehicle body begins, based on the movement of the arm of the control mechanism. Upon reaching a specific position within the movement path set up up to the starting position of the coating, the device moves at a second speed different from the first speed. The first speed and the second speed are constant.

2. The robot for car body painting according to claim 1, characterized in that, The second speed is set to be lower than the first speed.

3. The robot for car body painting according to claim 1, characterized in that, The first speed is set to be lower than the second speed.

4. The robot for car body painting according to claim 1, characterized in that, When the painting head reaches the painting start position, it begins painting the vehicle body while maintaining the second speed.

5. The robot for car body painting according to claim 1, characterized in that, The coating head reciprocates multiple times in the main scanning direction, and when switching to reciprocating movement in the main scanning direction, it moves a predetermined amount in the secondary scanning direction orthogonal to the main scanning direction. The coating start positions are respectively set in the path and loop of the reciprocating movement in the main scanning direction.

6. The robot for car body painting according to claim 5, characterized in that, The coating head moves at a third speed, which is lower than the second speed, when it moves a predetermined amount in the sub-scanning direction.

7. The robot for car body painting according to claim 1, characterized in that, The painting head remains in its initial position when the vehicle body is not being painted. The control mechanism controls the movement of the arm based on the start of painting on the vehicle body, causing the painting head to move from the initial position to the painting start position.

8. The robot for car body painting according to claim 1, characterized in that, 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 allows unused paint from the coating head to flow back to the storage section. The supply device has: The delivery mechanism delivers the coating stored in the storage section to the supply passage; A suction mechanism that draws the coating material from the coating head into the return path; The first testing agency tests the pressure of the coating fed into the supply passage; The second testing unit measures the pressure of the coating material drawn into the return flow path; as well as A pressure control mechanism controls the amount of paint dispensed by the delivery mechanism based on the detection results of the first detection mechanism, and controls the amount of paint inhaled by the suction mechanism based on the detection results of the second detection mechanism.

9. A robot for car body painting, characterized in that, include: The paint sprayer head sprays 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; as well as The arm portion has the painting head and the supply device. The robot for painting the car body moves the painting head in the main scanning direction by the movement of its arm while painting the car body. The robot for painting car bodies has a control mechanism for controlling the movement of the arm. The painting head, controlled by the control mechanism, moves to the painting start position where painting of the vehicle body begins and temporarily stops. After a predetermined time has elapsed since the temporary stop at the painting start position, it resumes movement from the painting start position toward the main scanning direction to paint the vehicle body. The moving speed of the paint head during the painting of the vehicle body is set to a different moving speed than the moving speed of the paint head when it moves to the starting position of the painting.

10. The robot for car body painting according to claim 9, characterized in that, The coating head reciprocates multiple times in the main scanning direction, and when switching to reciprocating movement in the main scanning direction, it moves a predetermined amount in the secondary scanning direction orthogonal to the main scanning direction. The coating start positions are respectively set in the path and loop of the reciprocating movement in the main scanning direction. The coating head temporarily stops at the coating start position respectively set on the outgoing path and the returning path.

11. The robot for car body painting according to claim 9, characterized in that, The painting head remains in its initial position when the vehicle body is not being painted. The control mechanism controls the movement of the arm based on the start of painting on the vehicle body, causing the painting head to move from the initial position to the painting start position.

12. The robot for car body painting according to claim 9, characterized in that, 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 allows unused paint from the coating head to flow back to the storage section. The supply device has: The delivery mechanism delivers the coating stored in the storage section to the supply passage; A suction mechanism that draws the coating material from the coating head into the return path; The first testing agency tests the pressure of the coating fed into the supply passage; The second testing unit measures the pressure of the coating material drawn into the return flow path; as well as A pressure control mechanism controls the amount of paint dispensed by the delivery mechanism based on the detection results of the first detection mechanism, and controls the amount of paint inhaled by the suction mechanism based on the detection results of the second detection mechanism.

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