Painting robot

Abstract

To provide a painting robot capable of improving painting productivity while improving painting quality. [Solution] The painting robot 1 paints the painting area of ​​the vehicle body FR and is equipped with a painting head 30 having a plurality of nozzles 32 that eject droplets of paint supplied from an external supply passage through an internal flow path 35, a robot arm 10 to which the painting head 30 is attached at its tip and which moves the painting head 30 to a desired position, and an arm control unit 42 that controls the operation of the robot arm 10, and the arm control unit 42 controls the operation of the robot arm 10 so as to impart a supply vibration to the painting head 30 to supply paint to the internal flow path 35 before painting the painting area.

Description

[Technical field]

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

[0002] If a paint head is not sufficiently filled with paint, there will be a shortage of paint inside the paint head, and the amount of paint ejected from the nozzle will be insufficient, which may result in poor paint quality such as missing paint or smearing. Therefore, Patent Document 1 discloses that in order to suppress vibrations of a paint head such as a print head that can lead to poor paint quality, the movement speed of the paint head is slowed down before painting begins, and the pressure of the paint flowing through the supply path and return path of the paint supply device and the pressure of the paint inside the paint head are kept within an appropriate pressure range. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7153816 Summary of the Invention [Problem to be solved by the invention]

[0004] The configuration disclosed in Patent Document 1 can suppress pressure fluctuations in the paint flowing through the supply and return paths of the paint supply device and inside the paint head, and may be able to suppress deterioration of paint quality. However, the above configuration has a problem in that it takes time to suppress pressure fluctuations in the paint, which reduces the painting speed.

[0005] The present invention has been made in consideration of the above circumstances, and has an object to provide a painting robot that is capable of improving painting productivity while improving painting quality. [Means for solving the problem]

[0006] A painting robot according to one aspect of the present invention comprises a painting head which paints a part to be painted on a vehicle body and has a plurality of nozzles which eject droplets of paint supplied from an external supply passage through an internal flow path, a robot arm which has the painting head attached to its tip and which moves the painting head to a desired position, and an arm control unit which controls the operation of the robot arm, and the arm control unit controls the operation of the robot arm so as to apply a supply vibration to the painting head to supply paint to the internal flow path before painting the part to be painted. Effect of the Invention

[0007] According to the present invention, it is possible to provide a painting robot that is capable of improving painting productivity while improving painting quality. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the schematic configuration of a painting robot according to this embodiment. [Figure 2A] FIG. 2A is an enlarged view showing a painting head of the painting robot according to the present embodiment. [Figure 2B] FIG. 2B is a front view showing a nozzle forming surface for ejecting paint in the painting head shown in FIG. 2A. [Figure 2C] FIG. 2C is a schematic diagram showing the internal flow passages in the paint head shown in FIG. 2A. [Diagram 3] FIG. 3 is a flowchart showing a flow of control performed in the main control unit of the painting robot according to this embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the state in which the painting head of the painting robot according to this embodiment moves to the painting position. [Diagram 5] FIG. 5 is a schematic diagram showing the arrangement of a plurality of passes to be performed by the painting head of the painting robot according to this embodiment. [Figure 6A] FIG. 6A is a schematic diagram showing a state after the painting head of the painting robot in the comparative example has performed painting passes. [Figure 6B] FIG. 6B is a schematic diagram showing a state after the painting head of the painting robot according to this embodiment has performed multiple passes of painting. [Figure 7] FIG. 7 is an enlarged view showing a painting head of a painting robot according to a modified example of this embodiment. [Figure 8] FIG. 8 is a schematic diagram showing the state in which the painting head of the modified painting robot according to the present embodiment moves to the painting position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the painting robot according to the present embodiment will be described with reference to the drawings. In order to clarify the directions in each drawing, XYZ coordinates are described except for FIG. 2C and the flow chart of FIG.

[0010] [Painting robot] 1 is a schematic diagram showing the schematic configuration of a painting robot 1 according to this embodiment. The painting robot 1 includes a robot arm 10, a painting head 30, and a control unit 40.

[0011] The painting robot 1 is disposed near a painting line in an automobile manufacturing plant, and paints a vehicle body FR transported along the painting line. In this embodiment, an automobile body FR is exemplified as an object to be painted, but the object may be something other than the automobile body FR.

[0012] The painting robot 1 paints the vehicle body FR that is transported from the upstream side of the painting line. In the painting process, the vehicle body FR may be painted while moving along the painting line, or the flow of the painting line may be stopped at a predetermined position and painting may be performed. The vehicle body FR that has been painted by the painting robot 1 is transported toward the downstream side of the painting line.

[0013] The painting robot 1 is exemplified as one in which the tip 24 can rotate in directions centered on three axes, the X-axis, the Y-axis, and the Z-axis, but the tip 24 may rotate about any one of the X-axis, the Y-axis, and the Z-axis, or may rotate about two axes.

[0014] Painting is carried out for the purpose of forming a coating film on the surface of an object to be painted in order to protect the surface and provide a beautiful appearance. The painting process includes cases where a paint of a specific color or a paint with a specific function is simply applied, and cases where paints of multiple colors or paints with specific functions are applied in sequence.

[0015] (Robot Arm) Although an articulated robot is illustrated as the robot arm 10, a SCARA robot may be used as long as it is capable of painting. As shown in FIG 1, the robot arm 10 includes a base 20, a leg 21, a rotary drive unit 22, an arm 23, and a tip 24.

[0016] The base 20 is a fixed member that fixes the robot arm 10 to the floor surface of a coating line and supports the robot arm 10. The base 20 may be movable on the floor surface of the coating line.

[0017] The leg 21 has a lower portion fixed to the base 20 and an upper portion connected to a rotation drive unit 22, and is extended to a vertical height suitable for painting by the robot arm 10.

[0018] The rotary drive unit 22 is connected to the upper end of the leg 21, and has a rotary shaft unit 25 and a rotary arm 26. The rotary shaft unit 25 rotates the rotary arm 26 around a direction parallel to the floor surface (the X-axis direction shown in FIG. 1) by a motor (not shown). The rotary arm 26 rotates the arm 23 connected to the rotary arm 26 around a straight line (the Z-axis direction shown in FIG. 1) that is perpendicular to the rotation center of the rotary shaft unit 25.

[0019] The arm 23 has a first rotating arm 27 and a second rotating arm 28. One end of the first rotating arm 27 is connected to the rotating arm 26, and the other end is connected to the second rotating arm 28. The first rotating arm 27 rotates around the Z-axis direction shown in FIG. 1 as a rotation center by a motor (not shown) mounted on the rotating arm 26. The second rotating arm 28 has one end connected to the first rotating arm 27, and has a wrist portion 29 (described later) at the other end. The second rotating arm 28 rotates around the Z-axis direction shown in FIG. 1 as a rotation center by a motor (not shown).

[0020] The tip portion 24 is disposed at the tip side of the robot arm 10 and sprays paint onto the vehicle body FR. A wrist portion 29 is held between the tip portion 24 and a second rotating arm 28. The wrist portion 29 rotates the tip portion 24 about at least one of the three axes (X-axis, Y-axis, and Z-axis) shown in Fig. 1. The tip portion 24 has a paint head 30 at its tip.

[0021] (Painting head) The painting head 30 will be described with reference to Figures 2A, 2B, and 2C. Figure 2A is an enlarged view of the painting head 30 of the painting robot 1 according to this embodiment. Figure 2B is a front view of the nozzle forming surface 31 that ejects paint in the painting head 30 shown in Figure 2A. Figure 2C is a schematic diagram showing the internal flow path in the painting head shown in Figure 2A.

[0022] An external supply path is laid inside or along the robot arm 10, and paint is supplied to the painting head 30 from the external supply path through an internal flow path 35 of the painting head 30. The painting head 30 has a plurality of nozzles 32 for ejecting droplets of the paint supplied from the internal flow path 35. The painting head 30 sprays paint at appropriate timing onto the vehicle body FR traveling on the painting line.

[0023] On the nozzle forming surface 31, multiple nozzle rows 33 each consisting of a large number of nozzles 32 are arranged side by side in a certain order. The painting head 30 sprays paint from each nozzle 32 at appropriate timing to form a coating film on the vehicle body FR, which is the object to be painted.

[0024] Here, the internal flow passage 35 disposed within the paint head 30 will be described.

[0025] 2C, the coating head 30 includes a large supply flow passage 77, a column-directional supply flow passage 78, a nozzle pressurizing chamber 79, a column-directional discharge flow passage 80, and a large discharge flow passage 81. The large supply flow passage 77 is a flow passage to which paint is supplied from the above-mentioned supply passage 61. The column-directional supply flow passage 78 is a flow passage to which the paint in the large supply flow passage 77 is diverted.

[0026] Furthermore, the nozzle pressurizing chamber 79 is connected to the column-directional supply flow passage 78 via a nozzle supply flow passage 79a. As a result, paint is supplied to the nozzle pressurizing chamber 79 from the column-directional supply flow passage 78. The nozzle pressurizing chambers 79 are provided in a number corresponding to the number of nozzles 32, and the paint inside can be ejected from the nozzles 32 using a piezoelectric substrate (not shown).

[0027] The nozzle pressurizing chamber 79 is also connected to a column-directional discharge flow path 80 via a nozzle discharge flow path 79b. Therefore, paint not ejected from the nozzle 32 is discharged from the nozzle pressurizing chamber 79 to the column-directional discharge flow path 80 via the nozzle discharge flow path 79b. The column-directional discharge flow path 80 is also connected to a discharge-side large flow path 81. The discharge-side large flow path 81 is a flow path where the paint discharged from each column-directional discharge flow path 80 joins together. This discharge-side large flow path 81 is connected to the return flow path 62.

[0028] With this configuration, paint supplied from the supply passage 61 passes through the supply large flow passage 77, the column-direction supply flow passage 78, the nozzle supply flow passage 79a, and the nozzle pressurizing chamber 79, before being discharged from the nozzle 32. Furthermore, paint that has not been discharged from the nozzle 32 passes from the nozzle pressurizing chamber 79 through the nozzle discharge flow passage 79b, the column-direction discharge flow passage 80, and the discharge large flow passage 81, and is returned to the return flow passage 62.

[0029] In this embodiment, the following control is performed to prevent a paint shortage in the internal flow passages 35 provided in such a coating head 30, which would result in non-ejection from the nozzles 32.

[0030] (Control unit) Returning to FIG. 1, the control unit 40 has a main control unit 41, an arm control unit 42, a paint supply control unit 43, a storage unit 44, and a head control unit 45.

[0031] Based on the information in the memory unit 44, the main control unit 41 transmits signals to the arm control unit 42, the paint supply control unit 43 and the head control unit 45 to control the movement of the painting robot 1 and the supply of paint.

[0032] The arm control unit 42 controls the movement from the rotation drive unit 22 to the painting head 30 based on a signal from the main control unit 41. The arm control unit 42 moves the painting robot 1 to a desired painting position, and moves the painting head 30 in the main scanning direction during painting. In an area where painting locations are arranged adjacent to each other as band-shaped painting passes P, the arm control unit 42 controls the main scanning direction of the painting head 30 to coincide with the extension direction of the painting passes P so that each painting pass P can be painted by reciprocating in order from the end side.

[0033] The paint supply control unit 43 controls the operation of pumps, flow path conversion valves, and the like that are interposed in the paint circulation path of the painting head 30 based on signals from the main control unit 41 .

[0034] Based on a signal from the main control unit 41, the head control unit 45 controls the driving of the piezoelectric substrate so that the paint head 30 ejects paint from the nozzle 32. The piezoelectric substrate changes the amount of paint ejected from the nozzle 32 by changing the driving frequency.

[0035] The memory unit 44 stores the shape of the vehicle body FR traveling on the painting line, and supplies the main control unit 41 with the data currently required from the previously stored data so that the painting head 30 does not interfere with the vehicle body FR. In addition, when painting multiple painting passes P consecutively, the memory unit 44 stores the painting passes P that have already been painted, and supplies the main control unit 41 with information regarding the painting passes P that have not yet been painted.

[0036] [Control Flow] Next, the control flow of the painting robot 1 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the control performed by the main control unit 41 of the painting robot 1 according to this embodiment. Note that the "horizontal direction" in the following description is merely a convenient expression of a direction parallel to the part to be painted, and does not mean a direction excluding a vertical component. This includes cases where the direction is completely horizontal and cases where it is not.

[0037] In step S1, the main control unit 41 determines whether the paint head 30 has started moving to the paint start position. If it is determined that the paint head 30 has started moving to the paint start position, the process proceeds to step S2, and if it is not determined that movement is occurring, the process of this step is repeated. The movement of the paint head 30 is performed by the arm control unit 42 based on a command from the main control unit 41. The movement to the paint start position refers to the movement of the paint head 30 from the initial position to a position where painting on the workpiece is to start.

[0038] In step S2, the main control unit 41 determines whether or not the paint head 30 is moving horizontally. If it is determined that the paint head 30 is moving horizontally, the process proceeds to step S3, and if it is not determined that the paint head 30 is moving horizontally, the process of this step is repeated.

[0039] In step S3, the main control unit 41 instantly switches the paint head 30 to a falling direction (second instantaneous direction switching control). When this step is processed, the paint head 30 is moving horizontally, so the paint head 30 instantly switches from horizontal movement to a falling direction. At this time, the instantaneous change in the moving direction of the paint head 30 causes paint to fill the paint head 30 due to inertial force, preventing a shortage of paint and an insufficient amount of paint discharged from the nozzle 32. When the moving direction of the paint head 30 changes instantaneously, the acceleration acting on the paint head 30 is 1.0 to 3.0 m / s 2 That's about it.

[0040] In step S4, the main control unit 41 judges whether the paint head 30 has fallen in the falling direction to a predetermined switching height. If it is judged that the paint head 30 has fallen to the predetermined switching height, the process proceeds to step S5, and if it is not judged that the paint head 30 has fallen to the predetermined switching height, the process of this step is repeated. The predetermined switching height is set to at least the height at which the object to be painted is to be painted.

[0041] In step S5, the main control unit 41 instantly switches the painting head 30 to the horizontal direction (first instantaneous direction switching control). When this step is processed, the painting head 30 is moving in the falling direction, so the painting head 30 instantly switches from moving in the falling direction to moving in the horizontal direction. At this time, just like when processing step S3, paint is filled into the painting head 30 by inertial force, preventing a shortage of paint and an insufficient amount of paint discharged from the nozzle 32. When the moving direction of the painting head 30 is instantly changed, the acceleration acting on the painting head 30 is 1.0 to 3.0 m / s 2 That's about it.

[0042] In step S6, the main control unit 41 moves the painting head 30 to a painting start position. The movement of the painting head 30 is performed by the arm control unit 42 based on a command from the main control unit 41.

[0043] In step S7, the main control unit 41 executes painting. Painting is performed while maintaining the painting head 30 at an appropriate angle relative to the workpiece by controlling the movement of the painting head 30 by the arm control unit 42 and the amount of paint discharged by the head control unit 45 based on commands from the main control unit 41. Also, based on commands from the main control unit 41, the painting head 30 and the paint supply control unit 43 control the amount of paint discharged from the nozzle 32 so that the painting pass P can be painted evenly from the painting start position.

[0044] In step S8, the main control unit 41 determines whether or not there is a next painting pass P. If it is determined that there is a next painting pass P, the process proceeds to step S1, and the arm control unit 42 moves the painting head 30 to the painting start position of the next painting pass P. If it is not determined that there is a next painting pass P, the process ends. The painting pass P will be described later.

[0045] [Effect] The operation of the painting robot 1 according to this embodiment will be described. Fig. 4 is a schematic diagram showing the transition of the painting head 30 of the painting robot 1 according to this embodiment to a painting position. Fig. 5 is a schematic diagram showing the arrangement of a plurality of painting passes P to be painted by the painting head 30 of the painting robot 1 according to this embodiment. The painting passes P are paths along which the painting head 30 ejects paint as it moves.

[0046] Fig. 4 shows the vehicle body FR, which is the object to be coated, as viewed from the side. Note that in Fig. 4, the height direction position of the paint head 30 is emphasized for easy understanding, and therefore differs from the actual height of the paint head 30. First, in order to paint the object to be coated, the arm control unit 42 starts to move the paint head 30 to the paint start position (point A in Fig. 4, YES in step S1).

[0047] Next, when it is determined that the movement of the paint head 30 is horizontal, the arm control unit 42 instantly changes the movement direction of the paint head 30 to the falling direction, i.e., changes the movement direction by approximately 90° (point B in FIG. 4, step S3). However, as long as the movement of the paint head 30 includes a component in the falling direction, the movement direction of the paint head 30 may be changed to a direction along a parabola, for example, in which the movement of the paint head 30 includes a horizontal component.

[0048] Next, when the height of the paint head 30 reaches the predetermined switching height, the moving direction of the paint head 30 is instantly changed to the horizontal direction, that is, the moving direction is changed by approximately 90° (point C in FIG. 4, step S5).

[0049] Next, when the painting head 30 reaches the painting start position (point D in FIG. 4, step S7), painting is performed.

[0050] After painting is completed (point E in FIG. 4), if there is a next painting pass P to be painted, the arm control unit 42 moves the painting head 30 to the next painting pass P. During such movement, the arm control unit 42 similarly performs the first instantaneous direction switching control and the second instantaneous direction switching control as described above.

[0051] Fig. 5 shows the vehicle body FR, which is the object to be coated, as viewed from above in the vertical direction. The painting start position shown in Fig. 4 is the rear of the vehicle body, which is at the bottom of the paper in Fig. 5, and painting is performed in the main scanning direction toward the front of the vehicle body, which is at the top of the paper. Fig. 5 shows seven painting passes P as an example, but the number of painting passes P varies depending on the width of the surface to be painted of the vehicle body FR, the width of the painting head 30, the overlap width of the paint, etc.

[0052] First, a series of first instantaneous direction switching control and second instantaneous direction switching control shown in the control flow of Fig. 3 are performed in painting pass P1. When it is determined in step S8 of Fig. 3 that there is a next painting pass P, the arm control unit 42 moves the painting head 30 to the rear end of the vehicle body in painting pass P2 to perform the next painting.

[0053] At this time, the arm control unit 42 may perform the first instantaneous direction switching control and the second instantaneous direction switching control while moving the painting head 30. Also, if there is a possibility that paint dripping from the nozzle 32 and adhering to other painting passes P due to the first instantaneous direction switching control and the second instantaneous direction switching control while the painting head 30 is moving to the rear end of the vehicle body of the painting pass P2, the first instantaneous direction switching control and the second instantaneous direction switching control may be performed during the preparation stage of moving the painting head 30 to the rear end of the vehicle body and from there to the painting start position of the painting pass P2, without performing the first instantaneous direction switching control and the second instantaneous direction switching control.

[0054] The method of performing the first instantaneous direction switching control and the second instantaneous direction switching control between the painting passes P is selected by the main control unit 41 depending on the positional relationship between the painting head 30 and the painting pass P at that time.

[0055] Similarly, when the painting head 30 finishes painting the painting pass P2 and the arm control unit 42 moves the painting head 30 to the rear end of the vehicle body for the painting pass P3, the first instantaneous direction switching control and the second instantaneous direction switching control may be repeatedly performed.

[0056] This allows the first instantaneous direction switching control and the second instantaneous direction switching control to be performed every time the painting head 30 moves to the first painting pass P1 in the painting process, as well as every time the painting head 30 moves to the next painting pass P after painting of each painting pass P is completed, so that a large inertial force acts on the paint in the nozzle 32, allowing the paint to be filled more reliably in the internal flow path 35 of the painting head 30.

[0057] It is not necessary to execute both the first instantaneous direction switching control and the second instantaneous direction switching control, and only one of them may be executed depending on the moving direction of the painting head 30.

[0058] Here, we will explain the painting result after the painting head 30 has painted multiple painting passes P. Fig. 6A is a schematic diagram showing the state after the painting head 30 of the painting robot 1 in the comparative example has painted multiple painting passes P. Fig. 6B is a schematic diagram showing the state after the painting head 30 of the painting robot 1 according to the present embodiment has painted multiple painting passes P.

[0059] 6A, in the comparative example, paint gaps and smudges occurred in some painting passes P, and the paint could not be applied uniformly in all painting passes P. It is believed that the paint in the internal flow passage 35 of the painting head 30 was insufficient, and the paint ran out before one painting pass P was completed from the painting start position, making it impossible to maintain the paint discharge pressure.

[0060] 6B, in this embodiment, painting can be performed uniformly and without unevenness in all painting passes P. By applying a large inertial force to the painting head 30, a sufficient amount of paint can be drawn into the internal flow passage 35 of the painting head 30 before painting, which prevents the paint from running out while scanning one painting pass P, as in the comparative example.

[0061] [Variations] Fig. 7 is an enlarged view showing the painting head 30 of the painting robot 1 according to a modified example of this embodiment. Fig. 8 is a schematic diagram showing the transition of the painting head to a painting position in the painting robot according to the modified example of this embodiment.

[0062] (Vibration generation and suppression) In the above embodiment, an example has been described in which a large inertial force is applied by suddenly changing the direction of movement of the paint head 30, thereby preventing the internal flow path 35 in the paint head 30 from being filled with paint by the inertial force, thereby preventing a shortage of paint and an insufficient amount of paint being ejected from the nozzle 32.In addition to this, vibration may be imparted to the paint head 30 by other configurations.

[0063] For example, in the above embodiment, as shown in FIG. 4 , the first instantaneous direction switching control suddenly changes the moving direction of the paint head 30 in the Y-axis direction, and the second instantaneous direction switching control suddenly changes the moving direction of the paint head 30 in the Z-axis direction, thereby applying an inertial force to the paint head 30. In addition to this, instantaneous direction switching control along the X-axis direction may be executed in which the moving direction of the paint head 30 is suddenly changed in the X-axis direction to apply an inertial force to the paint head 30.

[0064] Furthermore, instead of or in addition to suddenly changing the movement direction of the painting head 30 in the X-axis, Y-axis, and Z-axis directions as described above, the arm control unit 42 may apply an inertial force by performing rotation control to rotate the painting head 30 about at least one of the X-axis, Y-axis, and Z-axis relative to the robot arm 10 while the painting head 30 is moving from the movement start position to the painting start position of the part to be painted. The action of the painting head 30 when rotation control is performed will be described with reference to FIG.

[0065] Fig. 8 shows the vehicle body FR, which is the object to be coated, as viewed from the side. Note that in Fig. 8, the height direction position of the paint head 30 is emphasized for easy understanding, and therefore differs from the actual height of the paint head 30. First, in order to paint the object to be coated, the arm control unit 42 starts to move the paint head 30 to the paint start position (point F in Fig. 8).

[0066] Next, the arm control unit 42 rotates the paint head 30 about the Z axis while moving the paint head 30 in a predetermined movement direction (the Y-axis direction in FIG. 8). The state after rotation of approximately 90° is point G. The rotation direction of the paint head 30 is set based on the structure of the internal flow passage 35 inside the paint head 30, and the rotation speed of the paint head 30 is set based on the type, viscosity, temperature, etc. of the paint so that the internal flow passage 35 is sufficiently filled with paint, but the paint does not spurt out of the nozzle 32 due to centrifugal force and adhere to the vehicle body FR or other surrounding objects.

[0067] Next, when the rotation angle of the paint head 30 about the Z axis reaches the angle at which painting begins, the arm control unit 42 stops the rotation of the paint head 30 (point H in FIG. 8). After this, the arm control unit 42 fixes the rotation angle of the paint head 30 until painting is completed. After that, the arm control unit 42 continues to move the paint head 30, and when the paint head 30 reaches the painting start position (point I in FIG. 8), painting begins.

[0068] After painting is completed (point J in FIG. 8), if there is a painting pass P to be painted next, the arm control unit 42 moves the painting head 30 to the next painting pass P. During such movement, the arm control unit 42 may similarly perform rotation control as described above.

[0069] In the above modification, the painting head 30 is rotated about the Z axis, but it may be rotated about the X axis or the Y axis. The first instantaneous direction switching control and the second instantaneous direction switching control of the present embodiment and the instantaneous direction switching control and rotation control along the X axis direction of the above modification can be performed in combination according to the space from the movement start position to the painting start position.

[0070] In all of the above explanations, the X-axis, Y-axis, and Z-axis directions have been exemplified as oriented as shown in Fig. 4, but they do not necessarily have to be oriented as shown in Fig. 4, as long as the X-axis, Y-axis, and Z-axis are three axes perpendicular to one another. Furthermore, the movement and rotation of the painting head 30 do not have to be strictly in the directions along the X-axis, Y-axis, and Z-axis, or rotation around each axis, but a direction at a predetermined angle with each axis may be used as the movement direction, or a direction at a predetermined angle with each axis may be used as the rotation axis.

[0071] Furthermore, the head control unit 45 may have a vibration generating unit 51 that applies vibration to the paint head 30 and a vibration suppressing unit 52 that suppresses vibration of the paint head 30, as shown in FIG.

[0072] The vibration generating unit 51 is, for example, an eccentric motor or a linear vibrator, and vibrates the paint head 30 while the arm control unit 42 is transporting the paint head 30 to the paint start position. Since the paint quality deteriorates if the paint head 30 vibrates during painting, the paint head 30 is only vibrated while the paint head 30 is being transported and not being painted. In addition, taking into account the pressure fluctuation of the paint in the flow path from when vibration is stopped to when painting starts, the frequency of the vibration is set to a value within a range in which the pressure fluctuation quickly subsides.

[0073] This allows paint to fill the internal flow path 35 of the paint head 30, and old paint remaining in the nozzle 32 inside the paint head 30 is expelled from the nozzle 32, allowing new paint to flow into the nozzle 32.

[0074] The vibration suppression unit 52 is, for example, a gyroscope, and suppresses vibrations constantly generated by a drive motor (not shown) of the arm control unit 42 while the arm control unit 42 is transporting the paint head 30 to the paint start position. When the vibration suppression unit 52 is operating, the paint head 30 hardly vibrates, and when the vibration suppression unit 52 is not operating, the paint head 30 is vibrated by a drive motor or the like. By utilizing this effect, the paint head 30 can be vibrated by switching between a vibration suppression state and a suppression stop state at an appropriate timing. In this case, too, since the paint quality deteriorates if the paint head 30 vibrates during painting, the paint head 30 is vibrated only when the paint head 30 is not being painted and is being transported. In addition, taking into consideration the pressure fluctuation of the paint in the flow path from the stop of vibration to the start of painting, the frequency of vibration is set to a value within a range in which the pressure fluctuation quickly subsides.

[0075] This allows paint to fill the internal flow path 35 of the paint head 30, and old paint remaining in the nozzle 32 inside the paint head 30 is expelled from the nozzle 32, allowing new paint to flow into the nozzle 32.

[0076] [Supplementary explanation of the embodiment] The above-mentioned embodiments each show a preferred specific example of the present invention. The numerical values, components, arrangement positions of the components, and order of connection forms shown in the above-mentioned embodiments are merely examples and are not intended to limit the present invention. Also, each drawing is not necessarily a strict illustration.

[0077] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

[0078] [Note] The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0079] (1) Vibration for paint supply The painting robot 1 is equipped with a painting head 30 having a plurality of nozzles 32 that sprays droplets of paint supplied from an external supply passage through an internal flow path 35 and that paints the area to be painted on the vehicle body FR, a robot arm 10 that has the painting head 30 attached to its tip and moves the painting head 30 to a desired position, and an arm control unit 42 that controls the operation of the robot arm 10, and the arm control unit 42 controls the operation of the robot arm 10 to apply a supply vibration to the painting head 30 to supply paint to the internal flow path 35 before painting the area to be painted.

[0080] As a result, by applying supply vibrations to the painting head 30 under control of the arm control unit 42, paint can be filled into the internal flow path 35 of the painting head 30, thereby preventing a deterioration in painting quality, such as paint missing or smearing, due to an insufficient supply of paint to the internal flow path 35.

[0081] Furthermore, since no time is required to suppress pressure fluctuations within the flow passage, the productivity of coating can be improved.

[0082] (2) First instantaneous direction switching In addition, the arm control unit 42 may provide supply vibrations by performing a first instantaneous direction switching control in which the movement direction of the painting head 30 is changed to a falling direction while the painting head 30 is moving from the movement start position to the painting start position of the painting area, and then the movement direction is instantly switched to a parallel direction parallel to the painting area.

[0083] As a result, the arm control unit 42 performs first instantaneous direction switching control to instantly switch the moving direction of the paint head 30 from the falling direction to a direction parallel to the vehicle body FR, thereby applying supply vibration that exerts a large inertial force on the paint head 30 when the moving direction is switched. Therefore, paint can be supplied to areas in the internal flow passages 35 of the paint head 30 where paint is not sufficiently filled.

[0084] (3)Second instantaneous direction switching In addition, the arm control unit 42 may provide supply vibrations by performing a second instantaneous direction switching control in which the movement direction of the painting head 30 is instantaneously switched to a falling direction after an initial movement direction toward above the painting area while the painting head 30 is moving from the movement start position to the painting start position of the painting area.

[0085] As a result, the arm control unit 42 performs second instantaneous direction switching control to instantaneously switch the movement direction of the paint head 30 to the falling direction after setting it to the initial movement direction, and thus the paint head 30 is subjected to supply vibration with a large inertial force acting thereon by switching the movement direction twice. Therefore, paint can be supplied to areas in the internal flow passage 35 of the paint head 30 where paint is not sufficiently filled.

[0086] (4) For each painting pass In addition, the arm control unit 42 may apply the supply vibration for each painting pass P, which is a path along which the painting head 30 moves to eject paint relative to the painting site.

[0087] As a result, the arm control unit 42 applies the supply vibration to the painting head 30 for each painting pass P. Therefore, paint can be filled into the internal flow passage 35 in advance regardless of which painting pass P is to be performed. Therefore, in any painting pass P, deterioration of painting quality such as paint missing or smearing due to insufficient paint supply to the internal flow passage 35 can be prevented.

[0088] (5) Vibration generating means In addition, the painting robot 1 may be equipped with a vibration generating unit 51 that applies supply vibrations to the painting head 30, and the arm control unit 42 may control the operation of the vibration generating unit 51 so as to apply supply vibrations to the painting head 30 while the painting head 30 is moving from the movement start position to the painting start position of the painting area.

[0089] With this configuration, the paint can be filled into the internal flow passage 35 of the paint head 30 by providing the vibration generating unit 51 with a supply vibration to the paint head 30. This makes it possible to prevent deterioration of paint quality, such as paint missing or smearing, caused by an insufficient supply of paint to the internal flow passage 35.

[0090] Furthermore, since no time is required to suppress pressure fluctuations, it is possible to improve productivity in coating.

[0091] In addition to the instantaneous direction switching control of the painting head 30, by directly applying vibration to the painting head 30 using the vibration generating unit 51, paint can be filled not only into the internal flow path 35 but also into the nozzle 32, further preventing a deterioration in painting quality.

[0092] (6) Vibration suppression means In addition, the painting robot 1 is equipped with a vibration suppression unit 52 for suppressing vibration when vibration is applied to the painting head 30 by operation of the robot arm 10, and the arm control unit 42 may control the operation or stop of the vibration suppression unit 52 so as to apply supply vibration to the painting head 30 while the painting head 30 is moving from the movement start position to the painting start position of the painting area.

[0093] With this, by providing the vibration suppression unit 52 and controlling the operation or non-operation of the vibration suppression unit 52, it is possible to apply supply vibration to the paint head 30 and fill the internal flow passage 35 of the paint head 30 with paint. Therefore, deterioration of the paint quality, such as missing paint or smearing, due to an insufficient supply of paint to the internal flow passage 35 can be prevented.

[0094] Furthermore, since no time is required to suppress pressure fluctuations, coating productivity can be improved.

[0095] In addition to controlling the direction of the paint head 30, the vibration suppression of the paint head 30 can be switched on or off, resulting in vibration, which can fill the nozzle 32 as well as the internal flow path 35 with paint, thereby further preventing a deterioration in paint quality.

[0096] (7) Rotation control In addition, the arm control unit may apply the supply vibration by performing rotation control to rotate the painting head 30 relative to the robot arm 10 while the painting head is moving from the movement start position to the painting start position of the painting part.

[0097] As a result, the arm control unit 42 can apply centrifugal force to the paint head 30 by performing rotation control to rotate the paint head 30 relative to the robot arm 10. Therefore, a sufficient amount of paint can be supplied to the area in the internal flow passage 35 of the paint head 30 where paint is not sufficiently filled. [Explanation of symbols]

[0098] 1. Painting robot 10 Robot Arm 30 Painting Head 35 Internal flow path 32 Nozzles 42 Arm control section 51 Vibration generating unit 52 Vibration suppressor FR body P Paint pass

Claims

1. A painting robot that paints a painting portion of a vehicle body, a coating head having a plurality of nozzles for ejecting droplets of paint supplied from an external supply passage through an internal flow passage; a robot arm having a tip end to which the paint head is attached and which moves the paint head to a desired position; an arm control unit that controls the operation of the robot arm; Equipped with the arm control unit controls the operation of the robot arm to apply a supply vibration to the paint head, which generates an inertial force for supplying the paint to the internal flow path before painting the part to be painted, While the painting head is moving from a movement start position to a painting start position of the painting part, The supply vibration is applied by performing a first instantaneous direction switching control in which the moving direction of the painting head is changed to the falling direction and then is instantly switched to a parallel direction parallel to the painting part. A painting robot characterized by the above.

2. The painting robot according to claim 1, The arm control unit, while the painting head is moving from the movement start position to the painting start position of the painting part, the supply vibration is applied by performing a second instantaneous direction switching control in which the moving direction of the painting head is instantaneously switched to the falling direction after the moving direction of the painting head is set to an initial moving direction toward the upper part of the painting area. A painting robot characterized by the above.

3. 3. The painting robot according to claim 1, the arm control unit applies the supply vibration for each painting pass, which is a path along which the painting head moves relative to the painting site to discharge the paint, A painting robot characterized by the above.

4. The painting robot according to claim 1, a vibration generating unit that applies the supply vibration to the coating head, the arm control unit controls the operation of the vibration generating unit so as to apply the supply vibration to the painting head during movement of the painting head from a movement start position to a painting start position of the painting part. A painting robot characterized by the above.

5. The painting robot according to claim 1, a vibration suppression unit for suppressing vibration when vibration is applied to the painting head due to operation of the robot arm; the arm control unit controls activation or stop of the vibration suppression unit so as to apply the supply vibration to the painting head during movement of the painting head from a movement start position to a painting start position of the painting part. A painting robot characterized by the above.

6. The painting robot according to claim 1, The arm control unit, while the painting head is moving from a movement start position to a painting start position of the painting part, and applying the supply vibration by performing rotation control to rotate the painting head relative to the robot arm. A painting robot characterized by the above.

Images