JPS6117551B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of applying a plurality of paints of different types and colors using a painting robot.

There are various kinds of paints, and for example, as is well known, there are solid paints and metallic paints for car painting. It is known that the surface finish of solid paints improves when the gun distance, that is, the distance between the object to be painted and the painting gun, is slightly closer, while for metallic paints, on the other hand, the gun distance is slightly closer. It is known that defects such as metal bleeding are reduced when painted separately.
Note that gun distance properly refers to the distance between the surface to be painted and the tip of the painting gun, and will be used in this sense hereinafter.

In the past, attempts have been made to use painting robots to perform automatic painting instead of humans, but it is difficult to apply coating that takes full advantage of the above-mentioned properties of the paint, making it difficult to obtain high-quality paint. I couldn't do it. As a countermeasure to this problem, methods could be considered such as teaching the robot multiple types of painting operations depending on the paint and replaying them, or adjusting the gun distance by changing the gun mounting position depending on the object to be painted. . However, the former method has the drawback that the teaching work is complicated because it teaches one object to be painted for each type of paint, and in addition, the capacity of the storage device for storing the operation details becomes large, making it difficult to control equipment. This method was found to be expensive and difficult to implement in practice. In addition, in the latter method, the gun distance can be changed relatively easily, so it is effective in lot production where many parts are painted in a single color. However, in production lines where color changes are relatively frequent, The gun mounting position had to be changed manually each time the color was changed, and the disadvantage was that the number of man-hours involved was so great that automation using painting robots was rendered meaningless.

The present invention is intended to solve the above drawbacks,
When performing multiple types of painting using a painting robot, the objective is to provide a method that automatically maintains the desired gun distance for each paint and performs high-quality painting. To provide a method for reducing teaching work time and efficiently operating a painting robot to paint.

In the present invention, the distance between the object to be painted and the painting gun that should be maintained according to the type of paint such as metallic paint or solid paint is stored in advance in a painting robot control device, and the distance between the object to be painted and the painting gun is stored in advance in accordance with the type of paint, such as metallic paint or solid paint. By detecting the shape with a detection device, etc., and instructing the control device with this detection signal, the painting robot selects a predetermined paint and spray paints the object while maintaining a predetermined distance from the gun. It is characterized by

More specifically, the present invention uses a plurality of painting robots or a single painting robot and a painting specification command device that gives a painting specification signal to the painting robot according to the object to be painted, so that the object to be painted can be painted before the object is painted by the painting robot. Then, the command device outputs a specification signal to the coating robot, and according to this specification signal, the coating robot reproduces the operation while converting the coordinates of the teaching contents so as to maintain the preset gun distance, and This is a method of painting.

Furthermore, in the present invention, one gun distance is input to the painting robot control device, the painting operation for a certain object to be painted is taught based on that gun distance, and when reproducing, the gun distance corresponding to that signal is taught using an external signal. This is a painting method that uses a painting robot that can perform painting work on the object to be painted.

Hereinafter, the coating method of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram showing an example in which the method of the present invention is applied to automobile body painting. In the figure,
1, 2, 3 are car bodies, 4, 5 are phototubes,
6, 7, 8, and 9 are painting robots, 10 is a painting booth, and 11 is a conveyor.

The car body to be painted is transported to the conveyor 11.
The car type and required paint color type are first detected by phototubes 4 and 5 at the position of body 1 in the figure, and then this car body is conveyed to the position of body 2 or 3 in the figure, where it is painted. The required paint is applied by the robots 6, 7, 8, and 9 at a gun distance appropriate for the paint.

Next, the operation of the painting robot will be explained using FIG. In FIG. 2, numeral 31 indicates a phototube emitter, and 32 a phototube receiver. Usually, a plurality of these emitters 31 and receivers 32 are installed as shown in the figure, and the phototubes 4 and 3 shown in FIG. Let them play the role of This phototube detects a car type and paint color setting dog (not shown) attached to the automobile body, and a detection signal from this phototube is input to the paint specification command device 33 via the wiring 40. This coating specification command device 33 decodes the detection signal,
For example, as shown in FIG. 3, signals are divided into colors _C1 to _C15 . In this case, the signals for colors C ₁ to C ₁₅ are made to correspond one-to-one to the type of paint color to be painted. Further, the coating specification command device 33 is configured to be able to preset gun distances corresponding to the type of coating color using a diode matrix or the like. Gun distance signals corresponding to the paint color types are output from gun distances _L1 to _L5 shown in FIG.

These signals for colors C ₁ to C ₁₅ and gun distances L ₁ to L ₅ for setting the paint color type are inputted to the control device 34 of the painting robot via the wiring 41. The painting robot receives the above signal, selects a predetermined paint, and performs painting work at a predetermined gun distance.

In addition, in FIG. 2, 35 is a hydraulic unit;
36 indicates the painting robot body, and the hydraulic unit 3
The hydraulic pressure generated at 5 is transmitted to the painting robot body 36 via the hydraulic pipe 45, and drives an actuator (not shown) within the robot body 36. 43
44 indicates a signal line to a servo valve (not shown) that controls the actuator, and 44 transmits a signal from a position detector (not shown) for each axis built into the painting robot body 36 to the control device 34. The signal lines for Reference numeral 37 denotes a valve control box for opening and closing valves for each paint, and is connected to the control device 34 through a signal line 45. A paint hose 46 is connected to the paint gun 38.

Next, referring to FIG. 4, the painting robot main body 36 will be explained. As shown in FIG. 4, the painting robot main body 36 has a left and right rotation axis 21, a front and rear rotation axis 22,
It consists of a vertical rotation axis 23, a bending axis 24, a swinging axis 25, and a torsion axis 26, and has degrees of freedom in the X, Y, and Z directions.

The rotation angle of each axis is Θ ₁ to Θ ₆ , the distance between the longitudinal rotation axis 22 and the vertical rotation axis 23 is l ₁ , the distance between the vertical rotation axis 23 and the bending axis 24 is l ₂ , and from the bending axis 24 to the swing axis 25 is represented by l ₃ , and the distance from the swing axis 25 to the surface to be coated 26 is represented by l ₄ .

The teaching points of this painting robot expressed above are calculated using the following formula in a rectangular coordinate system in which the angles of each axis are exchanged, and are stored in X, Y, and Z.

When the movement taught to the painting robot is to be reproduced, the equation is inversely transformed while correcting the angle between the surface to be painted 26 and the swing axis 25, and the equation is changed from Θ ₁ to Θ ₅ .
Calculate and operate each axis. Therefore, by resetting the constant _l4 representing the distance from the swing axis 25 to the surface to be painted 26 using the gun distance signal, the gun distance can be changed during operation reproduction even during the same teaching. For example, if the distance from the tip of the gun to the swing axis 25 is 200 mm, the gun distances are 200, 250,
Each l ₄ corresponding to 300, 350, 400mm is 400, 450,
Set to 500, 550, 600mm.

The painting robot of the present invention is thus capable of reproducing operations at any gun distance, regardless of the gun distance set during teaching. By storing the distance _l4 corresponding to the gun distance signal inputted from the painting specification command device in advance in the control device of the painting robot, the necessary gun distance can be automatically selected.

In the present invention, by using a painting robot configured as described above, when an automobile body as an object to be painted is conveyed by a conveyor 11 to the position of the body 1 shown in FIG. a coating specification command device 33 that issues a signal and receives this signal;
The control device 34 issues a command, selects the necessary paint and gun distance, and performs painting. The coating is performed by the coating robots 6, 7, 8, and 9 as described above.

In the example explained above, a phototube is used to input signals related to the car model and required paint color to the control device, but instead of the phototube, a person inputs using a numeric keypad or snap switch, etc. It is also possible to have a painting robot do the painting work in the same way as above. In this case, a worker is required in front of the painting booth, but this worker can also perform other tasks.

Furthermore, it goes without saying that even if the function of the painting specification command device is incorporated into the control device of the painting robot, the robot can be operated in the same way.

To describe the effects of the present invention more specifically,
In the case of painting using conventional painting robots, the gun distance was fixed at 250 mm even when painting solid paints such as baked enamel paints and metallic paints such as acrylic enamel paints, so the solid paints had a slightly poor texture. Metallic paints caused some metal unevenness.

In contrast to the above, in the painting method of the present invention, the painting robot can arbitrarily select the gun distance, so the gun distance is 230 mm for solid paint and 280 mm for metallic paint.
When painting with the gun distance set to , good quality paint was obtained for each.

Furthermore, according to the painting robot used in the present invention, there is no need for work to adjust the gun distance, and the taught painting operation is performed in the same way even if the gun distance is changed. No work is required to create a program. Furthermore, since a large number of operation programs are not required even for different paints, there is also the advantage that the capacity of the storage device in the control device of the painting robot can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a plan view for explaining the coating method of the present invention, Fig. 2 is a block diagram showing an example of a coating robot, Fig. 3 is a partial circuit diagram inside the coating specification command device,
FIG. 4 is a schematic diagram showing the degree of freedom of the painting robot. In the figure, 1, 2, 3...car body, 4, 5...
...Phototube, 6,7,8,9...Painting robot, 3
1...Phototube emitter, 32...Phototube receiver, 33...Painting specification command device, 34...Control device, 35...Hydraulic unit, 36...Painting robot body, 38...Painting gun.

Claims (1)

[Claims] 1 The distance between the object to be painted and the painting gun that should be maintained depending on the type of paint, such as metallic paint or solid paint, is stored in advance in the control device, and the object being transported is painted by the painting robot. By detecting the type, shape, etc. of the object to be painted and instructing the control device with the detection signal, the painting robot can select a predetermined paint and set a predetermined gun distance to the object. The painting method is characterized in that the object to be painted is spray-painted by reproducing the taught action while maintaining the selected gun distance.