JPH11290734A - Coating robot controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating robot controlling device capable of keeping the amt. of the paint depositing on a material to be coated constant with a simple structure. SOLUTION: A temp. sensor 6 is provided to detect the temp. of the paint supplied to a coating gun 2, and the amt. of the paint depositing on a material 10 to be coated is kept constant by a robot controller 3 based on the change of temp. detected by the sensor 6 by correcting the distance between the coating gun 2 and the material 10 and/or the traveling speed of the gun 2 or both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a coating robot for automatically coating an object to be coated by moving a coating gun at a predetermined speed while maintaining a predetermined distance from the object to be coated.

[0002]

2. Description of the Related Art Conventionally, there has been provided a painting robot for automatically spray painting an object to be painted.

[0003] In this coating robot, a coating gun is mounted on the wrist of the robot to perform automatic coating in order to uniformly finish the thickness of the coating film adhered to the surface of the object to be coated. At that time, in order to secure a uniform thickness of the coating film, the amount of paint discharged from the coating gun, the mist spread shape formed by the paint discharged from the coating gun (that is, a perfect circular shape,
The discharge shape pattern such as an elliptical shape), the moving speed of the coating gun, and the distance between the coating gun and the workpiece (that is,
It is required that all of these four conditions, such as the distance between works, be constant. Strictly speaking, the amount of the paint discharged from the paint gun and the mist spread shape formed by the paint discharged from the paint gun (that is, the discharge shape pattern such as a perfect circle and an ellipse) are strictly related to the paint. Varies with temperature.

Therefore, conventionally, a heating means is provided in a paint supply pipe to control the paint temperature to a predetermined value (Japanese Patent Application Laid-Open Nos. 4-48953 and 4-66151). Japanese Patent Application Laid-Open No. 61-78 discloses a method in which a set pressure value of a pressure control valve provided in a pipe is changed in accordance with a paint temperature.
No. 457), the flow rate of the paint supplied to the coating gun was kept constant.

[0005]

However, in the above-mentioned conventional apparatus provided with a heating means in the paint supply pipe,
Since many auxiliary devices such as a heating device and a temperature control device are required and their control is also required, there has been a problem that the production cost increases. In addition, since a bypass or a circulation path is required in the paint supply pipe, the pipe itself becomes complicated, energy for heating increases, and there are problems that the number of maintenance steps increases.

Further, in the above-described conventional apparatus having a pressure control valve in the paint supply pipe, an auxiliary machine for controlling the flow rate by pressure is required, and the control is also required, so that the production cost is increased. There was a problem of doing. In addition, there is a problem that it is not possible to cope with a change in the discharge pattern only by controlling the flow rate with respect to the pressure.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has as its object to provide a painting robot capable of maintaining a constant amount of paint adhered to a workpiece with a simple structure. To provide a control device.

[0008]

According to a first aspect of the present invention, there is provided a control apparatus for a coating robot, wherein a coating gun is maintained at a predetermined distance from an object to be coated. By moving at a speed, in a coating robot for automatically coating the object to be coated, based on a temperature detecting means for detecting the temperature of the paint supplied to the coating gun, and a change in the temperature detected by the temperature detecting means. ,
To keep the amount of paint adhered to the object to be coated constant,
Correction means for correcting one or both of the distance between the coating gun and the object and the moving speed of the coating gun is provided.

According to a second aspect of the present invention, there is provided a control apparatus for a painting robot according to the first aspect, wherein the correction means is configured to control a flow rate of the paint based on a temperature change of the paint supplied to the painting gun. Is changed, the moving speed of the coating gun is corrected based on the change in the temperature detected by the temperature detecting means. This allows
Since the moving speed of the coating gun changes according to the change in the flow rate of the paint, the amount of the paint adhering to the object to be coated can be kept constant.

According to a third aspect of the present invention, there is provided a control apparatus for a painting robot according to the first aspect, wherein the correction means is configured to change the temperature of the coating gun supplied to the coating gun. When the discharge pattern from the object changes, the distance between the coating gun and the object to be coated is corrected based on the change in the temperature detected by the temperature detecting means. As a result, the distance between the coating gun and the object to be coated changes according to the change in the discharge pattern of the coating gun.
When rotating, the width (pattern width) of the paint that adheres to the object to be coated in a strip shape can be kept constant.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of a painting robot of the present invention. The coating robot 1 has a coating gun 2 mounted on its wrist 1a, and has a predetermined gun-work distance D1 (see FIG. 2) and a gun speed V1 based on a command from a robot controller (control device) 3. To be painted 10
The painting gun 2 is programmed to operate along the painted surface 8 of the above. FIG. 1 shows a state where the camera is operated at the speed V1 in the downward direction. A constant amount of paint is supplied to the paint gun 2 by a paint supply pipe (paint hose) 4 and a paint pump device 5. A temperature sensor (temperature detecting means) 6 for detecting the temperature of the paint flowing in the paint supply pipe 4 is attached to the paint supply pipe 4 near the coating gun 2. The signal is transmitted to the robot controller 3 via a signal line 7.

As shown in FIG. 2, the coating material 20 discharged from the coating gun 2 spreads in a fan shape around the nozzle 21 of the coating gun 2 and, on the coating surface 8 of the object 10 to be coated, for example, a horizontally long elliptical shape. Reach with the paint pattern. At this time, the discharge amount of the paint 20 from the paint gun 2 (that is, the flow rate of the paint in the paint supply pipe 4) changes depending on the temperature of the paint and also on the type of the paint to be used. Draw a temperature-flow curve as shown in FIG.

The spread angle A1, which indicates the ratio of fan-shaped spread, changes depending on the temperature of the paint to be discharged and also on the type of paint to be used. For example, the spread angle A1 shown in FIG. Draw.

As described above, since the discharge amount of the paint from the paint gun 2 changes depending on the temperature of the paint, if the operation speed V1 of the paint gun 2 is always constant, the spraying on the paint surface 8 by one spraying is performed. T1 of the coating film 8a formed on the substrate
Changes in proportion to the discharge amount. Therefore,
In the present invention, the operating speed V1 of the coating gun 2 is corrected in accordance with the temperature of the coating material in order to keep the thickness T1 of the coating film 8a constant regardless of the temperature of the coating material. For example, if the temperature of the paint rises, the speed V1 is increased.

The coating material 20 discharged from the coating gun 2
Since the spread angle A1 changes depending on the temperature of the paint, if the gun-work distance D1 is always constant, 1
Coating 8a formed on painted surface 8 by multiple sprays
Changes in proportion to the spread angle A1. Therefore, in the present invention, the gun-work distance D1 is corrected according to the paint temperature in order to keep the width W1 of the coating film 8a constant regardless of the paint temperature. For example, if the temperature of the paint rises, the distance D1 is reduced.

In order to implement these corrections, of the contents of the program for operating the robot stored in the robot controller 3, the value V1 of the operating speed of the painting gun 2 for each teaching point is as follows: V1 = v It is described by the product of a constant part v (c) and a variable part v (v), as in (c) · v (v). The value D1 of the gun-work distance for each teaching point is described by the product of a constant part v (c) and a variable part d (v), such as D1 = d (c) · d (v). ing.

Therefore, a data conversion table for converting the input value of the paint temperature input from the temperature sensor 6 into the two variable parts v (v) and d (v) is stored in the robot controller 3. This data conversion table is obtained by replacing the temperature-flow rate curve shown in FIG. 3 and the temperature-spread angle curve shown in FIG. 4 with numerical data that can be read by the robot controller 3. That is, claims 1 to 3
Is implemented by the robot controller 3.

Next, the operation of the coating robot having the above configuration will be described with reference to the flowchart shown in FIG. 5 and the operation path diagram of the coating gun 2 shown in FIG.

As for the operation path of the coating gun 2, various paths can be set. Here, as shown in FIG. 6, coating is performed while reciprocating up and down from upper right to lower left. And Therefore, as shown in FIG. 6, each teaching point on the coating surface 8 of the workpiece 10 is assigned a serial number from 1. That is, the upper right teaching point is No. 1, the teaching point immediately below it is No. 2, the teaching point moved to the left by a predetermined width from the second and second teaching points is No. 3, and the teaching point just above the third teaching point is The teaching points moved to the left by a predetermined width from the teaching points No. 4 and No. 4 are designated as No. 5 and so on, and numbers are sequentially assigned to the lower left teaching point (No. n) on the painted surface 8. I have.

The temperature sensor 6 constantly transmits the value of the paint temperature in the paint supply pipe 4 to the robot controller 3. During the operation, the robot controller 3 reads the value of the paint temperature from the temperature sensor 6 when trying to operate from a certain teaching point (for example, No. 5) to the next teaching point (for example, No. 6) ( In step S1), variable parts v (v) and d (v) of the operation speed of the coating gun 2 and the distance between the gun and the work are calculated with reference to the data conversion table (step S2), and the operation is performed based on them. Then, the corrected values V1 and D1 of the operation speed and the distance between the gun and the work are calculated (step S3).

The robot controller 3 performs the same correction calculation as above at any time during the operation between all the teaching points during the operation, and operates the painting robot based on the calculated corrected values V1 and D1. That is, the operation of the coating gun 2 is executed (step S4). Thus, even if the temperature of the paint changes during the operation of the coating robot 1, the thickness T1 and the width W of the coating film are not affected by the change in the temperature.
1 can be kept constant in thickness and width.

The robot controller 3 repeats this operation up to the last teaching point (No. n) on the painted surface 8 (from step S5 to step S1), and paints up to the last teaching point (n). Then, the painting operation of the painted surface 8 ends.

[0024]

According to the present invention, there is provided a control apparatus for a coating robot, which controls a coating gun and an object to be coated so as to maintain a constant amount of coating on the object based on a change in temperature detected by temperature detecting means. And / or the moving speed of the paint gun, the temperature change of the paint can be achieved without using auxiliary equipment such as heating equipment, temperature control equipment, or pressure flow control equipment. The thickness and width of the coating film can be maintained at a constant thickness and width without being affected by the thickness. Further, since no auxiliary machine is used, the manufacturing cost can be reduced accordingly. In addition, since the painting supply line can have a simple configuration, maintenance man-hours can be reduced,
Excess paint stagnation in the paint supply line can be reduced.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a painting state by a painting robot of the present invention.

FIG. 2 is an explanatory view showing a state of spraying on a painted surface by a painting gun.

FIG. 3 is a temperature-flow rate curve diagram of a paint.

FIG. 4 is a graph showing a temperature-spreading angle curve of a paint.

FIG. 5 is a flowchart for explaining the operation of the painting robot of the present invention.

FIG. 6 is a diagram illustrating an example of an operation path of a coating gun.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 painting robot 2 painting gun 3 robot controller (control device) 4 paint supply pipeline 5 paint pump device 6 temperature sensor (temperature detection means) 8 painting surface 10 object to be painted

Claims (3)

[Claims] 1. A coating robot for automatically coating an object to be coated by moving the coating gun at a predetermined speed while maintaining the coating gun at a predetermined distance from the object to be coated. Temperature detection means for detecting the temperature of the coating gun, and based on a change in the temperature detected by the temperature detection means, the coating gun and the object to be coated, so as to maintain a constant amount of paint adhered to the object to be coated And a correction means for correcting one or both of the distance and the moving speed of the coating gun. 2. When the flow rate of the paint changes due to a change in the temperature of the paint supplied to the coating gun, the correction means detects the change in the temperature of the coating gun based on the temperature change detected by the temperature detecting means. The control device for a painting robot according to claim 1, wherein the control device corrects a moving speed. 3. When the discharge pattern from the coating gun changes due to a change in the temperature of the paint supplied to the coating gun, the correction unit is configured to perform the correction based on a change in the temperature detected by the temperature detection unit. The control device for a coating robot according to claim 1, wherein the control device corrects a distance between the coating gun and the object to be coated.