JP2007260531A - Coating discharge control system in robot coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that effective utilization of a coating and highly precise coating are not satisfactory due to low adaptability of the coating discharge rate in adjustment of atomization corresponding to coating sites of a workpiece although a robot coating is highly versatile. <P>SOLUTION: In the coating robot provided with a manipulator with a spray gun mounted on operated based on given data and a controller controlling the operation of the manipulator, the mounted spray gun and the like, a coating supplying device operated and controlled by the controller is constituted of a pressure sensor and a gear pump driven by a servomotor of which the number of revolution is controlled by the output signal from the controller, is explosion-proof, and is installed in the vicinity of the manipulator arranged at the coating place to make the length of a coating hose connected to the spray gun shortest. The gear pump is controlled linked with the given data and operated in synchronism with a spray signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a paint control system that enables the setting of a discharge amount related to painting finish by a painting robot to be applied according to a painting part of an object to be painted, and enables effective use of the paint and improvement of the accuracy of the painting finish.

In robot painting, a coating locus for an object to be coated is taught in advance, and a stable painting is automatically performed by repeatedly regenerating it. At present, high-precision operation control is possible, and high-quality coating can be automatically obtained by programming appropriate data according to teachings, so that it is increasingly used for a wide variety of objects to be coated.

In normal spray painting, the spray pattern is adjusted according to the object to be painted, and it is effective and appropriate for the part to be painted. In the simplest case, a large area is painted with a large pattern and narrow. It is desirable that the painted portion of the range is painted so that the pattern is made small so that the paint is not wasted.

These adjustments can also be made in the painting robot by controlling the supply pressure of the pattern adjustment air to the spray gun. When teaching the painting robot, the pattern adjustment is performed together with the operation of the spray gun and the spray gun spraying operation. It has already been done to memorize spray control including air supply and pressure adjustment so as to perform appropriate coating in accordance with the coating condition of the object to be coated.

In addition, when the pattern is small, reducing the paint discharge amount accordingly can save paint and effectively use it, but it is difficult to install a discharge amount adjustment valve on the spray gun, and it is generally supplied to the spray gun. Since the amount of paint ejected from the paint nozzle changes by adjusting the paint supply pressure to be applied, the spray gun only opens and closes the paint valve, and sets the supply pressure from the paint supply device or the pressure adjustment valve. The discharge amount is adjusted.

Up to now, a technique for adjusting the discharge amount by adjusting the supply pressure of paint is disclosed in Japanese Patent Application Laid-Open No. 11-76887. However, in the case of setting the paint pressure, the pressure ejected from the paint nozzle of the spray gun is adjusted. It fluctuates due to changes in pressure, etc. depending on the length and installation state of the paint hose and the height position of the spray gun, and it is difficult to eject the paint hose at a set constant pressure.

In addition, the length from the supply device to the spray gun, including the pressure adjustment of the paint, affects the responsiveness, and it takes time until the pressure actually ejected from the paint nozzle of the spray gun reaches the supply pressure controlled and controlled. Therefore, it is very difficult to immediately change the discharge amount according to the spray pattern.

For this reason, the coating is usually performed with the discharge amount kept constant, or the distance from the supply control device or the pump to the spray gun must be reduced as seen in the above document. However, in these methods, a complicated paint supply path must be attached to the arm of the painting robot, resulting in an increase in maintenance load of related equipment and a problem that impairs the operability of the painting robot.

On the other hand, a gear pump is known as a device that can obtain a stable and accurate discharge amount in terms of the quantitative property of paint supply. In the case of this pump, an excluded volume proportional to the number of revolutions is obtained, and control is easy by controlling the number of revolutions of the servo motor, which is particularly effective when performing precise coating with a small discharge amount.

These paint supply methods are also disclosed in Japanese Patent Application Laid-Open No. 2003-10742, which also discloses a technique for reliably managing the discharge amount by monitoring the discharge amount. On the other hand, since the discharge amount of the gear pump is determined by the rotation, when the clogging occurs on the spray gun side, the pressure in the supply hose increases, resulting in a problem of bursting. That is, since the spray gun that is freely moved toward the paint surface is connected to the paint supply device by a flexible paint hose, the pressure-resistant danger described above remains. In addition, since it is not as rigid as metal, there is a tendency for fluctuations to occur during discharge from the paint nozzle due to pressure accumulation due to pressure fluctuations in the supply hose, which increases as the supply hose becomes longer.
JP-A-11-76887 JP 2003-10742 A

The versatility of robot painting is high, but there is still room for improvement in the effective use of paint and high-precision painting due to insufficient spray adaptability in the spray adjustment according to the part to be painted. ing. The present invention is capable of setting and teaching the discharge amount of the paint suitable for the spray pattern corresponding to each painting part for each painting step for the diversified objects to be coated, in conjunction with the operation of the manipulator. An object of the present invention is to provide a system capable of expanding the use of robot painting by enabling painting with a coating (discharge amount). In implementing this system, it is intended to improve the above-mentioned conventional problems and provide a simple and safe device.

An operation of a painting robot including a manipulator mounted with a spray gun and operated based on the taught data and a control device for controlling the operation of the manipulator and the mounted spray gun is controlled by the control device. The paint supply device is composed of a gear pump driven by a servo motor whose rotation speed is controlled by an output signal from the control device and a pressure sensor, and the gear pump drive signal is stored for each step of the teaching data of the painting robot. The gear pump is operated in synchronization with the sprayed data in synchronization with the spray signal.

The detection value of the pressure sensor is sent to the control device, and when the abnormality is detected, the gear pump is stopped and a warning display accompanying it is output.

The paint supply device has explosion-proof specifications and is installed in the vicinity of the manipulator disposed at the painting position, and the length of the paint hose connected to the spray gun is set to a short distance.

With the above configuration, by applying the present invention, painting using a painting robot can be performed at an appropriate paint discharge amount in each painting step, and high application efficiency and precision can be achieved under high-precision paint discharge amount management. Can be painted. In particular, when it is desired to adjust the discharge rate conditions according to the part to be coated and perform coating with an appropriate discharge rate, based on the data taught at each coating step, Coating can be performed with the required amount of discharge, and the accuracy can be performed with high accuracy, so that there is no waste of paint, which can lead to reduction in coating cost and environmental improvement.

Even if the spray gun side has some trouble, for example, even if the paint nozzle is clogged, by providing a pressure sensor, immediately detect the abnormal pressure and stop the gear pump operation so as not to cause problems such as rupture of the paint hose. Can be used safely.

In addition, the paint supply device can be installed at the painting position by adopting an explosion-proof specification, and it can be adjusted by making the distance from the spray gun operated by the painting robot closer and minimizing the length of the paint supply hose connecting them. Responsivity can be improved to a level where there is no practical problem with respect to a change in the amount of paint discharged.

According to the present invention, the use of a gear pump makes it possible to perform spray painting without waste by the amount of paint discharged in accordance with the coating site, and not only can the paint consumption be reduced, but also the problems caused by the use of the gear pump. It will be possible to improve the system and make it a system that can be used safely.

Embodiments of the present invention will be described below. FIG. 1 is a diagram for explaining an outline of a paint control system in painting according to the present invention. The individual equipment and its configuration have already been clarified by some implementation examples and technical information, and details are omitted here.

As shown in FIG. 1, the control system of the present invention comprises a painting robot main body having an arm 1 driven with several degrees of freedom (number of axes that can be controlled) as a memory reproduction type manipulator, A robot coating device having a control device 2 for driving control is used.

The painting is sequentially performed on an object (not shown) by a spray gun 3 mounted on the arm 1 while moving according to the painting surface. Normally, the movement and spray control of the spray gun 3 are taught as the trajectory and operating conditions of the spray operation based on the skilled painting technique, and the stored data at that time is sent from the control device 2 to the main body of the painting robot, spray gun or It is output to the gun controller, paint supply device, etc., and regeneration is repeated in the same state as the taught coating conditions.

The gun controller 4 specifies the operating conditions of the spray gun 3 and controls the operations necessary to perform proper painting. The gun controller 4 controls spray ON-OFF, spray pattern, and the like. In general, in such robot painting, an automatic spray gun is used in which the spray gun 3 is operated by the supply of spraying air pressure and spraying is performed. Is provided and controlled.

Also, if necessary, for the spray gun with a separate pattern adjustment air control means, the spray pattern size can be changed by arbitrarily controlling the supply pressure of this pattern adjustment air, so that the part to be coated can be applied. It is also possible to adjust the pattern width to a necessary value, and a pattern adjustment pressure control valve may be provided as the control means.

In most cases, the paint valve for controlling the discharge of the paint is interlocked by the spraying air pressure supplied at the time of spraying, and is not individually controlled.

The supply device 5 uses a gear pump 6 as a pump for supplying the paint in the paint container 15 to the spray gun 3. The gear pump 6 is a unit that sends out a fixed amount of paint sucked into the space volume by the rotation of the teeth, and is not limited to the shape of the teeth. Some so-called gear pumps are used.

These gear pumps 6 are driven by a drive motor 7 such as a servo motor for the fixed amount supply, and the number of revolutions is controlled by a signal output from the control device 2 of the painting robot. These rotational speed controls are output and controlled to the drive motor 7 from the control device 2 in which the rotational speed corresponding to the required discharge amount is stored based on the specification of the gear pump 6 specified in advance. In the present invention, the drive motor 7 rotates on the basis of the data stored for each step according to the coating part of the object to be coated, and spraying is performed with a discharge amount corresponding to the coating part.

In the gear pump 6 that discharges the paint corresponding to the rotation, the paint corresponding to the rotation of the drive motor 7 is discharged by the output from the output control device 2 and supplied to the spray gun 3 through the paint hose 8 and discharged as it is. The amount is discharged from the spray gun 3. However, as described above, when the paint nozzle of the spray gun is clogged for some reason, the pressure on the discharge side increases and there is a risk that the supply paint hose 8 is damaged.

For this reason, in the present invention, the pressure sensor 9 is provided on the discharge side of the gear pump 6, and when the abnormal pressure rises in the discharge side passage, this pressure is detected and the drive of the gear pump 6 is immediately stopped by the control device 2. It has a configuration to inform

Further, the supply device 5 has an explosion-proof specification, and can be installed in the vicinity of a manipulator installed at a coating position by being configured to be used in an explosive atmosphere. A paint hose 8 for supplying paint to the spray gun 3 is provided. Can be shortened. The longer the paint hose, the larger the volume accumulated in the interior due to the paint supply pressure, and the responsiveness of the paint ejected from the paint nozzle decreases. Therefore, when precise coating is required depending on the object to be coated, the paint discharge amount can be immediately changed to an appropriate value in accordance with the change in the painted part by adopting the above configuration.

As described above, the control device 2 includes a storage device and an arithmetic processing device as control devices for the painting robot, and performs control output of related equipment. In the figure, a manipulator control 21 and a paint supply device control 22 which operate as a painting robot body directly related to the present invention are shown. A display 23 for the input, output, calculation result, warning for the abnormal pressure rise or the like for these controls is provided as necessary to facilitate the operation.

A switching valve 10 provided between the paint and the gear pump 6 is provided for switching the path with the cleaning liquid 11 when the paint is changed, and is configured to operate in response to a command from the control device 2. . A drain valve 12 provided in the supply path to the spray gun 3 is a switching valve for recovering waste liquid from the cleaning.

With a system that can adjust and manage the paint discharge rate for each painting site according to the painting specifications by the painting robot, it can be expanded to high-precision coating fields that use expensive paint with a small discharge amount, which was unsuitable until now. The robot can be used in a wider range than ever, such as a significant improvement in work efficiency, which is the effect of robots, and a reduction in painting costs.

It is a figure for demonstrating the outline | summary of the coating control system of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Robot arm 2 Control apparatus 3 Spray gun 4 Gun controller 5 Supply apparatus 6 Gear pump 7 Drive motor 8 Paint hose 9 Pressure sensor 10 Switching valve 11 Cleaning liquid 12 Drain valve 15 Paint container 16 Waste liquid 21 Manipulator control 22 Supply apparatus control 23 Display

Claims (3)

An operation of a painting robot including a manipulator mounted with a spray gun and operated based on the taught data and a control device for controlling the operation of the manipulator and the mounted spray gun is controlled by the control device. The paint supply device is composed of a gear pump driven by a servo motor whose rotation speed is controlled by an output signal from the control device and a pressure sensor, and the gear pump drive signal is stored for each step of the teaching data of the painting robot. Discharge paint control system in robot painting that operates the gear pump in synchronization with the sprayed data in synchronization with the sprayed data. 2. The discharged paint control system according to claim 1, wherein a detected value of the pressure sensor is sent to a control device, and a stoppage of the gear pump and / or a warning display associated therewith is output by detecting an abnormality. The discharge paint control system according to claim 1, wherein the paint supply device has explosion-proof specifications and is installed in the vicinity of a manipulator disposed at a painting position so that the length of the paint hose connected to the spray gun is a short distance.

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