JPH04371252A - Coating machine system - Google Patents

Abstract

PURPOSE:To provide a coating machine system capable of recoating the uncoated part while monitoring the coating condition of a work. CONSTITUTION:A first coating stage 3, an inspection stage 4 and a second coating stage 5 are provided on the way of a conveyor 1 for conveying a body 2, and coating robots 6 and 7 to conduct coating while being transferred by transfer devices 8 and 9 are set in the first coating stage 3. Sensors 42a-42d for monitoring the uncoated part of the body 2 coated in the first coating stage 3 are furnished in the inspection stage 4. When the uncoated part is detected by the sensors 42a-42dw and the point position is designated by a sensor controller 43, the control data on the point position are corrected by a host computer 47, the correction data are outputted to the coating robots 51 and 52 in the second coating stage 5, and the uncoated part is recoated by the robots 51 and 52.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a coating machine system.
In particular, the present invention relates to a coating machine system that monitors the coating state of a workpiece and controls a subsequent coating machine so as to recoat unfinished areas.

0002

2. Description of the Related Art For example, in a painting line for painting the bodies of automobiles, a coating machine system is employed in which coating robots serving as coating machines are disposed on both sides of a conveyor device for conveying the bodies. As this type of painting robot, an articulated playback robot with a painting gun attached to the end of its arm is often used. The painting robot is installed on a trolley of a moving device that can move parallel to the conveyor device, and performs painting work while following the conveyance of the workpiece.

[0003] Furthermore, control data that is taught so that the coating gun passes through coating points according to the shape of the workpiece is input to a robot control device that controls the coating robot. Then, when the start switch detects that the body as a workpiece has arrived at the start position, the robot control device causes the painting gun to pass through the taught point based on the control data input in advance and reach a predetermined position. Control a painting robot to perform painting work.

[0004] As a teaching method, for example, PTP (
A teaching method (POINT TO POINT) is adopted, so that the paint gun sprays paint while passing through each taught point. Therefore,
When inputting teaching data, the painting gun was taught to pass through each point, and linear interpolation was performed between each point using calculations by the control circuit. In addition, teaching the painting section from the start of painting to the stop of painting,
During robot teaching operations, each point was memorized with painting data indicating "paint on."

However, after teaching the painting points as described above, when the painting operation is actually performed, the operating speed of the painting robot, the distance between the painting gun and the workpiece, and the paint tube connected to the painting gun change. Also, due to factors such as internal resistance of the atomizing air tube or malfunction of the coating gun, the coating point may shift, resulting in unpainted areas or thinly coated areas.

[0006] For this reason, in conventional painting machine systems, when the painting robot finishes painting, an optical sensor is used to check whether there are any unfinished areas on the painted surface of the body, and the entire body is coated uniformly. If there are areas that have been painted, it is determined that the painting is complete, but if there are any unfinished areas, the painting line is stopped and a buzzer sounds to notify the operator. Then, the operator corrects the control data of the robot control device by changing the movement of the coating gun in the unfinished areas and eliminates the unfinished areas.

[0007]

[Problem to be Solved by the Invention] However, in the conventional coating machine system, if an unpainted area is discovered after the painting robot finishes painting, the operator must correct the control data himself. However, there were problems in that the correction work was time-consuming and it took time for the painting line to restart.

[0008] Furthermore, in order to manually correct the control data,
Due to a correction error, it may not be possible to completely eliminate the unpainted area, and some unfinished areas may remain. In this case, the correction work must be redone, resulting in twice the effort.

[0009] Accordingly, an object of the present invention is to provide a coating machine system that solves the above problems.

0010

[Means for Solving the Problems] The present invention provides a monitoring means for monitoring the coating state of a workpiece after the painting process has been completed by a coating machine in the preceding stage, and detecting an unfinished portion of the painted surface of the workpiece by the monitoring means. an unfinished part specifying means for specifying the position of the unfinished part, and a subsequent coating machine so as to paint the unfinished part at the position specified by the unfinished part specifying means. and data correction means for correcting data.

[0011]

[Operation] When an unpainted portion is discovered on the painted surface of the workpiece by the monitoring means, its position is designated by the unfinished painting portion specifying means. The data correction means automatically corrects the control data of the subsequent coating machine so as to paint that position, and paints the unpainted portion.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 show an embodiment of a coating machine system according to the present invention. Note that FIG. 1 is a plan view showing the entire system in a simplified manner. Further, in this embodiment, a painting robot system will be explained.

[0013] In each figure, the painting robot system performs a first (previous stage) series of painting operations while an automobile body 2 as a workpiece conveyed by a conveyor 1 passes through a painting position La. A painting process 3, an inspection process 4 in which the paint condition is checked while the body 2 passes the inspection position Lb after the first painting process 3, and an inspection process 4 while the body 2 passes the coating position Lc after the inspection process 4. and a second painting step 5 in which a second (latter stage) painting is performed.

[0014] Normally, in the painting process of the automobile body 2, the body 2 is painted multiple times, and in this embodiment, the first painting process and the second painting process are illustrated. Further, in FIG. 1, a hatched workpiece 2 indicates that it has been painted. Conveyor 1 for painting process 3
Painting robots 6, 7 as paint machines are provided on both sides of the conveyor 1, and each painting robot 6, 7 is provided on a moving device 8, 9 extending parallel to the conveyor 1. Therefore, when the body 2 arrives at the painting process 3 and the start switch 10, which is a limit switch or optical sensor, is turned on, the painting robots 6 and 7 perform the painting work while moving in the transport direction (X direction).

As shown in FIG. 4, the painting robot 6 is an articulated playback robot, which is controlled by control signals from a robot control device 11 and executes painting work taught in advance.

In FIG. 4, a swing drive section 15 is provided on the base 14. As shown in FIG. A swing base 16 that rotates around an axis A fixed to the base 14 is provided above the swing drive unit 15 . A bracket 16a on the swing base 16 is provided with a support 17 that rotates around an axis B. As shown in FIG. Furthermore, a support column drive section 18 is provided on the bracket 16a on the swing base 16.

An arm 19 that rotates about an axis C is rotatably provided at the upper end of the support column 17. An arm drive section 20 is provided at the connection between the arm 19 and the support column 17. Furthermore, a wrist drive section 21 is provided at the rear of the arm 19.

Furthermore, a wrist mechanism 22 is provided at the tip of the arm 19. The wrist mechanism 22 includes a case 23.
, 24 and a mounting shaft 25 are provided. The case 23 is configured to rotate around an axis D. The case 24 is configured to rotate around an axis E. The mounting shaft 25 is a mounting portion for the coating gun 26, and is configured to rotate around the axis F.

The robot control device 11 stores teaching data and controls the operation of the painting robot 6 in conjunction with the conveyance of the body 2. Therefore, in the painting robot 6, each drive section is driven by a command from the control device 11, and each movable section such as the turning base 16, the support column 17, the arm 19, the wrist mechanism 22, etc. is operated. The painting gun 26 provided at the tip of the arm 19 moves to each point a, b, c, . . . as shown in FIGS.
Move and paint body 2.

In FIG. 5, when each movable part operates as described above, a rotational position detection signal from a potentiometer (not shown) provided in each movable part is sent to the input circuit 2 of the control device 11.
8 is input.

The A/D conversion circuit 29 converts the analog signal (rotational position detection signal) from the input circuit 28 into a digital signal.

Reference numeral 30 denotes a control circuit, which has a storage section 30A for storing teaching data and robot position data from the A/D conversion circuit 29. Further, a teaching data input device 31 for inputting teaching data is connected to the control circuit 30.

The control circuit 30 controls robot operation control data and the coating gun 2 according to a coating program inputted in advance.
6 on/off data is calculated. 33 is a D/A conversion circuit that converts the position command data output from the control circuit 30 into an analog signal. 34 is a servo amplifier, D
The deviation between the command signal from the /A conversion circuit 33 and the position feedback signal from the input circuit 28 is determined, amplified, and outputted to each driving section of the painting robot 6.

The paint gun 26 also includes a paint tube 35,
One end of the air tube 36 is connected. The other end of the paint tube 35 is connected to a paint supply device 37, and the other end of the air tube 36 is connected to an air source 38. Further, a paint valve 39 is disposed in the middle of the paint tube 35, and an air valve 40 is disposed in the middle of the air tube 36. Therefore, the paint gun 26 is supplied with paint and atomizing air by opening the paint valve 39 and the air valve 40, and sprays the paint onto the body 2 as a workpiece.

Reference numeral 41 denotes an I/O unit which inputs on/off data of the painting gun 26 from the position data of the painting robot 6 into the control circuit 30, and at the same time is calculated by the control circuit 30 and outputs a painting on/off signal. is output to the paint valve 39 and air valve 40 to control the painting operation of the paint gun 26.

The coating operation and teaching operation of the coating gun 26 will now be explained.

As shown in FIG. 6, the coating gun 26 moves in the Z direction and swings vertically via the arm 19 and wrist mechanism 22, so that the paint spraying direction is perpendicular to the surface to be coated. The orientation relative to the surface is adjusted.

It should be noted that the direction (rotation angle α) of the coating gun 26 is the largest in the counterclockwise direction when it is in the raised position G, and becomes downward. The coating gun 26 paints the upper side of the body 2 while gradually rotating clockwise as the arm 19 descends. When the arm 19 descends to approximately the center of the body 2, the coating gun 26 is oriented in the horizontal direction. As the arm 19 further descends, the coating gun 26 gradually rotates clockwise from the horizontal direction and points upward. The coating gun 26 thus rotates at the rotation angle α (α1
~α7) is changed and the side surface of the body 2 is painted while changing its direction with respect to the body 2.

In the process of the arm 19 rising from the lowered position H to the raised position G, an operation opposite to that during the lowering described above is performed, and the paint spraying direction of the coating gun 26 is adjusted.

Further, the rotation angle of the painting gun 26 in the C direction shown in FIG.
By inputting operation programs for bodies 2 having different shapes in advance, it is possible to correspond to a plurality of types of vehicles. In the above embodiment, the moving locus of the coating gun 26 in the Z and Y directions is determined using a circular arc I that approximates the side surface shape of the body 2 as a virtual shape. Therefore, the paint gun 26
The locus of movement is also an arc. However, by changing the program of the robot control device 11, the paint gun 26 can also be operated to faithfully trace the side shape of the body 2 in accordance with the side shape of the body 2.

Furthermore, the painting gun 26 is connected to the arm 19 and the support 1.
Due to the movement of 7, the distance L is approximately constant relative to the painted surface of body 2.
Move horizontally so as to maintain 1. Furthermore, as shown in FIG. 7, when the body 2 is viewed from above, the vehicle widths L2 and L3 at the bonnet 2a and trunk 2b sides located at the front and rear of the body 2 are smaller than the vehicle width L4 at the center (L
4 >L3 >L2).

Therefore, when painting the bonnet 2a side or the trunk 2b side, the paint gun 26
Move to point J on the side. That is, as the body 2 is transported in the X1 direction, the painting gun 26 gradually moves away from the body 2 and moves from point J to point K so as to maintain the distance L1 from the body 2. When the central part passes, it moves toward the body 2 side again, returning from point K to point J.

Therefore, even if the side surface shape of the body 2 is curved when viewed from above, the paint gun 26 has a distance L1 from the painted surface.
Trace the side shape while keeping the . Further, by inputting operation programs for vehicle types with different side shapes into the robot control device 11 in advance, it is possible to handle different vehicle types.

Further, as shown in FIG. 8, the front and rear bonnet 2a and trunk 2b sides of the body 2 are lower than the center portion. Therefore, the amplitude of the paint gun 26 in the Z direction is L0 at the center, but on the bonnet 2a side and the trunk 2a side.
On the b side, L5 and L6 become smaller (L0 > L5 >
L6). Therefore, since the body 2 is conveyed at a constant speed by the conveyor 1, the Z-direction movement trajectory of the coating gun 26 relatively takes a zigzag shape as shown in FIG.

In this way, in the painting robot 6, the painting gun 26 can move L0 in the Z direction (between G and H) and Ls in the Y direction (between J and K) with respect to the painting surface, and can also move up and down. Since the paint gun 26 can be rotated in the direction, the distance L1 between the paint surface and the paint gun 26 can be kept substantially constant regardless of the shape of the paint surface, and the paint gun 26 can be oriented to spray paint from a direction perpendicular to the paint surface. Can be done. Therefore, the paint gun 26
The paint sprayed from the paint is uniformly applied to the painted surface, which not only further improves the quality of the paint, but also enables efficient painting in accordance with the side shape of the body 2.

Teaching data for a painting operation for the shape of the body 2 as a workpiece is inputted via the input device 31 and stored in the storage section 30A of the control circuit 30. That is, as shown in FIGS. 6 to 8, the mobile robot 6 is taught so that the coating gun 26 moves to each point a, b, . . . , and the side shape of the body 2 is The painting section is set so that the painting point facing the area is the painting section.

The painting robot 7 disposed on the opposite side of the conveyor 1 to face the painting robot 6 has the same configuration as the painting robot 6 and performs the same painting operation. A detailed explanation of the painting robot 7 will be omitted.

However, as mentioned above, the paint tube 35
After the paint valve 39 and the air valve 40 are opened due to internal resistance in the air tube 36, the paint gun 26 is opened.
There may be a time delay until more paint is sprayed. Even in this case, since the paint gun 26 moves to a, b, c, . . . as taught, the paint may not be sprayed even though it has passed the painting point.

Furthermore, if the paint gun 26 or the paint supply device 17 or the like breaks down during the painting operation, a portion of the body 2 will have unfinished painting (an unpainted portion, a thinly painted portion).

[0040] Therefore, an inspection process 4 is provided downstream of the first coating process 3. In this inspection step 4, first and second sensors 42a and 42b are provided as monitoring means on both sides of the conveyor 1 and move in the Z direction (vertical direction),
3rd and 4th moving in the Y direction across conveyor 1
sensors 42c and 42d are provided. Each of the sensors 42a to 42d is composed of a light reflection type optical sensor, detects the coating rate of the painted surface, and outputs a signal corresponding to the coating rate to the sensor control device (unfinished area specifying means) 43. .

As shown in FIG. 9, the sensor control device 43
a sensor output determination unit 44 that receives signals from each of the sensors 42a to 42d and determines whether there is an unpainted portion;
While the body 2 passes through the inspection process 4, the first and second sensors 42a and 42b on both sides are moved in the vertical direction (Z direction), and the front and rear third and fourth sensors 42c and 42d are moved in the Y direction. It has a sensor movement control section 45 for moving the sensor, and a point position specifying section 46 for specifying the point position of an unfinished painted section when that section is discovered.

Sensor output determination 44 and sensor movement control section 4
5, when the body 2 is detected by the sensing switch 48 provided at the entrance of the inspection process 4, inspection of unpainted parts is started.

When the point position specifying unit 46 receives a signal from the sensor output determining unit 44 that detects an unfinished painted area, it reads the point position from the sensor movement control unit 45 and outputs the data to the host computer 47. .

The host computer 47 instructs the subsequent painting robot 51 to paint the unpainted portion at the position designated by the point position designation section 46, as will be described later.
, 52 is provided.

The host computer 47 is connected to the robot control device 11 of each robot, and, as will be described later, discovers unfinished areas of painting and executes control data correction processing. The body whose unpainted parts were inspected in the inspection process 4 configured as above is conveyed to the conveyor 1 and sent to the second coating process 5.
transported to. In this second painting step 5, painting robots 51 and 52 are provided on a pair of moving devices 49 and 50 arranged on both sides of the conveyor 1. Note that the second painting process 5 has the same configuration as the first painting process 3 described above, so a detailed explanation thereof will be omitted. Therefore, when the body 2 that has been inspected in the inspection step 4 is detected by the start switch 53, the painting robots 51 and 52 execute the painting work while being moved in the X direction by the moving devices 49 and 50. Here, the operation of inspecting and correcting unfinished areas of painting in the coating machine system configured as described above will be explained with reference to FIGS. 10 and 11.

In FIG. 10, the host computer 47 performs the first
Check whether the painting work in painting process 3 has been completed. Therefore, when the painting work on the body 2 is completed in the first painting process 3, a "painting completion signal" is sent from the robot control device 11 of the painting robots 6 and 7 to the host computer 4.
7 is output. Therefore, when the body 2 painted in the first painting process 3 is conveyed to the inspection process 4 by the conveyor 1, the sensing switch 48 is turned on, and this changes the traveling speed of the conveyor 1, that is, the conveyance position of the body 2. The corresponding pulses are counted (S2, S3).

In the next step S4, the first and second sensors 42a
, 42b in the vertical direction, and the third and fourth sensors 42c, 42d in the Y direction to inspect the painted surface of the body 2. In the next step S5, it is checked whether all inspections of the body 2 have been completed, and the process of S4 is executed until the inspection of the body 2 from the hood 2a side to the trunk 2b side is completed.

Each of the sensors 42a to 42d is a light reflection type optical sensor, so if there is an unfinished part of the body 2, the intensity of the light reflected from that part will change. 44, it is determined that there is an unfinished portion of painting.

[0049] In S6, the inspection results of the painted surface painted in the first painting process 3 are confirmed, and if the sensor control device 43 does not output a signal specifying the position of the unfinished part, it is determined that the painting is OK. I judge that. In that case, the control data normally performed in the second painting process 5 is output to each robot control device 11 of the second painting process 5 to be performed next (S7),
The painting robots 51 and 52 are caused to perform normal painting work (S8).

However, each sensor 42a to 4 in the inspection process 4
When the unpainted portion is detected by step 2d and a signal specifying the point position is output from the point position specifying section 46, the process moves from S6 to S9, and the position of the point position of the unpainted portion is read.

[0051] Then, in S10, the data of the painting point of the unpainted part and several points before and after it are corrected so that the next painting robots 51, 52 will paint the unpainted part.

As shown in FIG. 11, the control data of the painting robot is for each painting point A1 to A in the painting section described above.
m is input so that the painting operation is performed at the painting speed V1. However, if an unpainted part is found, the painting speed in the section from 2 points before to 2 points after that part is set to V1-v=V2.

That is, if an unfinished part of painting is found at painting point An, painting points An-2 to An+
The painting speed in the range of 2 is corrected to V2, which is slower than V1.

In the next step S11, normal control data and correction data in which the painting speed is corrected to V2 as shown in FIG. 11 are output to each robot control device 11 for the next painting process 5. Then, the process moves to S8, and the painting robots 51 and 52 of the second painting process 5 are caused to perform normal painting work and painting work on unpainted parts based on the correction data.

The painting robots 51 and 52 are equipped with painting guns 26.
When the painting point reaches the corrected painting point, the speed of the painting gun 26 is reduced from V1 to V2, and the unpainted part and the area before and after it are repainted. Therefore, even if the passing position of the painting gun 26 is slightly shifted, the unpainted portion that occurred in the first painting process 3 is reliably painted.

In addition, maintenance such as investigation of the cause of unfinished areas, correction of painting delays, and repair of the painting gun 26 in the first painting process 3 is performed during breaks or after the end of the day. Therefore, even if unpainted parts are discovered during painting work, the unpainted parts can be automatically repainted without stopping the line.

Although an articulated playback robot has been described as an example of the painting robot, other painting machines, such as a painting machine that uses a reciprocator to operate the painting gun 26, may also be used. can also be applied.

Further, in the above embodiment, a pair of painting robots are provided for one painting process (one station), but one painting robot or a plurality of painting robots other than two may be provided. In addition, when multiple paint machines are installed along the conveyor in one painting process, a sensor is installed between each paint machine to remove unfinished areas caused by painting by the paint machine in the previous stage. The coating may be applied using a coating machine.

Furthermore, the sensor of the monitoring means is not limited to a reflective optical sensor, but may also be an image sensor using a CCD (charge coupled device) to inspect the painted surface. It goes without saying that the present invention can also be applied to systems for painting workpieces other than automobile bodies.

[0060]

[Effects of the Invention] As described above, in the coating machine system according to the present invention, when an unpainted part is discovered on the painted surface of a workpiece by the monitoring means, the point specified by the unfinished part specifying means is painted. Since the data correction means automatically corrects the control data for the next coating machine, unpainted areas can be accurately repainted by the subsequent coating machine without stopping the coating line. In addition, since the control data is corrected fully automatically, labor saving and unmanned operation can be achieved, and there is no need to stop the painting line, eliminating unfinished areas without reducing the work efficiency of the painting line. It has the following features:

[Brief explanation of drawings]

FIG. 1 is a plan view showing the overall configuration of an embodiment of a coating machine system according to the present invention.

FIG. 2 is a plan view of a first painting process.

FIG. 3 is a front view of the first coating process viewed from the workpiece conveyance direction.

FIG. 4 is a perspective view of the painting robot.

FIG. 5 is a block diagram showing a schematic configuration of a robot control device.

FIG. 6 is a front view for explaining the painting operation of an automobile body.

FIG. 7 is a plan view for explaining the painting operation of an automobile body.

FIG. 8 is a side view for explaining the painting operation of an automobile body.

FIG. 9 is a block diagram for explaining the configuration of an inspection process.

FIG. 10 is a flowchart for explaining processing executed by a host computer.

FIG. 11 is a diagram for explaining control data and correction data of a painting robot.

[Explanation of symbols]

1 Conveyor 2 Body 3 First painting process 4 Inspection process 5 Second painting process 6, 7, 51, 52 Painting robot 8, 9, 49,
50 Movement device 11 Robot control device 26 Painting guns 42a to 42d Sensor 43 Sensor control device 44 Sensor output determination section 45 Sensor movement control section 46 Point position specification section 47 Host computer

Claims (1)

[Claims] 1. Monitoring means for monitoring the coating state of a workpiece that has been finished with a coating process by a coating machine in the previous stage; Unfinished painting part specifying means for specifying the position of the part; and data correction means for correcting control data of a subsequent coating machine so as to paint the unfinished part at the position specified by the unfinished painting part specifying means. A coating machine system comprising: