WO2022201325A1 - Painting robot - Google Patents

Abstract

According to the present invention, a painting robot, in which a plurality of arms have painting heads, reduces the adhesion of paint to other arms. This painting robot 1 has: one base part 2; a plurality of arms 3 extending from the base part 2; and a control device, wherein at least one of the plurality of arms 3 has a painting head 31 with a high deposition rate.

Description

painting robot

The present invention relates to a painting robot.

　Painting robots are widely used to automate the painting of automobile bodies. As one aspect of a general coating robot, a robot in which one coating nozzle is attached to the tip of a 6-axis vertical articulated industrial robot is widely used.

A painting line that uses a large number of painting robots has a long total length and requires a large installation area. Therefore, a coating robot having a plurality of arms is being studied in order to increase the integration of coating robots. For example, Patent Document 1 discloses that a robot having a plurality of arms can be provided with a coating device such as a rotary bell at the tip of each arm. Further, Patent Document 2 discloses that an industrial robot having a plurality of arms can be applied to painting work.

Japanese Patent Application Laid-Open No. 2005-501745 (or International Publication No. 2003/021519) Japanese Utility Model Laid-Open No. 1-156887

However, when operating a painting robot that has painting heads at the tips of multiple arms, interference between the arms can become a problem. In painting robots, in addition to the physical interference between the arms, the paint discharged from the painting head attached to a specific arm interferes with the painting work of the other arms. It is also necessary to consider the form of interference, such as paint adhering to the work target site of another arm, and there are greater restrictions when providing a plurality of arms compared to robots used in other industrial fields. However, the robots of Patent Documents 1 and 2 do not consider such problems.

Therefore, in a painting robot in which multiple arms have painting heads, it is required to reduce the interference of paint with other arms.

A coating robot according to the present invention comprises a base, a plurality of arms extending from the base, and a control device, wherein at least one of the plurality of arms is a coating head with a high coating rate. characterized by having

According to this configuration, since a coating head with a high coating rate is provided, most of the coating material discharged from the coating head attached to each arm adheres to the object to be coated and preferably interferes with the other arms. can be avoided. The painting head used in this configuration has a high coating rate, but on the other hand, the area that can be painted per unit time is relatively small. Therefore, the productivity of the painting work can be effectively improved without excessively increasing the installation area of the painting robot.

Preferred embodiments of the present invention will be described below. However, the scope of the present invention is not limited by the preferred embodiments described below.

As one aspect of the coating robot according to the present invention, the coating head preferably has a coating rate such that 90% or more of the coating discharged from the coating head adheres to the object to be coated.

According to this configuration, it is possible to more effectively prevent the paint discharged from the coating head from adhering to other arms.

As one aspect of the coating robot according to the present invention, the control device controls a range where the overmist of the paint discharged from the coating head reaches and a range in which the distance from the range is equal to or less than a predetermined distance. It is preferable that the movement of each of the plurality of arms can be controlled so as to prevent the arms from entering.

According to this configuration, it is possible to more effectively prevent the paint discharged from the coating head from adhering to other arms.

In one aspect of the coating robot according to the present invention, the control device controls each of the plurality of arms such that the distance between the coating head and the object to be coated is within a range in which the coating head does not overspray. It is preferable that the operation of is configured to be controllable.

According to this configuration, the amount of paint that does not adhere to the object to be coated can be further reduced, so that the adhesion of paint to other arms can be more suitably avoided.

As one aspect of the painting robot according to the present invention, it is preferable that the control device is configured to be able to control the motion of each of the plurality of arms within a range in which each of the arms does not interfere with another object. .

With this configuration, it is possible to avoid physical interference between the arms and physical interference between the arms and the object to be coated.

As one aspect of the painting robot according to the present invention, each of the plurality of arms has an encoder, and the control device can control the operation of each of the plurality of arms based on an electrical signal emitted by the encoder. is preferably configured to

According to this configuration, physical interference between the arms and physical interference between the arms and the object to be coated can be more precisely avoided.

As one aspect of the painting robot according to the present invention, it is preferable that the control device is configured to be able to control the motion of each of the plurality of arms based on image data obtained by photographing the plurality of arms.

According to this configuration, physical interference between the arms and physical interference between the arms and the object to be coated can be more precisely avoided.

In one aspect of the painting robot according to the present invention, the control device is configured to be able to correct teaching data relating to control of the plurality of arms based on image data obtained by photographing the plurality of arms. preferable.

With this configuration, the teaching data can be corrected precisely, and the coating quality can be improved.

In one aspect of the painting robot according to the present invention, the base has a load sensor capable of detecting a load applied to the base, and the control device detects when the load exceeds a predetermined threshold, and the base is It is preferable that it is configured to be able to determine that it is overloaded.

According to this configuration, for example, it is easy to prevent problems in the painting robot caused by uneven load.

In one aspect of the painting robot according to the present invention, at least two of the plurality of arms have the painting heads, and the control device controls the painting heads when cleaning the painting heads. It is preferable to control a plurality of said arms so as to sequentially guide each to the cleaning device.

According to this configuration, even if the number of installed cleaning devices is less than the number of coating heads, it is possible to suppress the waiting time for cleaning. This can reduce the number of installed cleaning devices.

Further features and advantages of the present invention will become clearer from the following description of exemplary and non-limiting embodiments described with reference to the drawings.

It is a figure which shows the use condition of the coating robot which concerns on embodiment. 1 is a block diagram of a coating robot according to an embodiment; FIG.

An embodiment of a painting robot according to the present invention will be described with reference to the drawings. An example in which the coating robot according to the present invention is applied to a coating robot 1 capable of coating an automobile body V (an example of an object to be coated) will be described below.

[Configuration of coating robot]
A coating robot 1 according to this embodiment includes one base 2, a plurality of arms 3 extending from the base 2, and a control device 4 (FIGS. 1 and 2). A general painting robot conventionally used in the field of painting generally has a structure in which one arm extends from one base. procrastinating.

The base 2 is configured to be rotatable around an axis perpendicular to the installation surface. Rotational movement of the base 2 allows adjustment of the general orientation of the entire painting robot 1, such as pointing the three arms 3 toward the vehicle body V. FIG. Rotational movement of the base 2 is controlled by the controller 4 .

Also, the base 2 is provided with a load sensor 21 capable of detecting the load received by the base 2 . The load sensor 21 detects, for example, the load applied to the base 2 by the motion of the arm 3 .

In this embodiment, three arms 3 are provided. The motion of each arm 3 including the base 2 is the same as that of a conventional 6-axis vertical articulated industrial robot. Therefore, the movement of each arm 3 is realized by operating respective motors controlling six axes in the base 2 and each arm 3 . The teaching point of each arm 3 can be designated by a known method such as an axis pulse format, a world coordinate system space coordinate format, or the like. The operation of the arm 3 (the operation of the motors controlling each axis) is controlled by the control device 4 .

A first painting head 31A (painting head 31) is provided at the tip of the first arm 3A, and a second painting head 31B (painting head 31) is provided at the tip of the second arm 3B. The coating head 31 is a high coating rate type coating head, and preferably has a coating rate such that 90% or more (based on mass) of the paint discharged from the coating head 31 adheres to the object to be coated. Specifically, the coating head 31 in this embodiment may be, for example, a coating head of an electrostatic atomization method or a jet nozzle method. machine. As is clear from these examples, the coating rate of the coating head 31 is at a high level that can be achieved only by a limited number of the various coating head systems.

On the other hand, a door opener 32 is provided at the tip of the third arm 3C. The door opener 32 is a jig for opening and closing the door D of the vehicle body V, and is configured as a hook-shaped member in this embodiment. When the third arm 3C is operated while the door opener 32 is engaged with the door D, the door D follows the movement of the third arm 3C, whereby the door D can be opened and closed. Since the painting robot 1 can open and close the door D using the door opener 32, both the outside and the inside of the door D can be painted. Further, by interlocking opening and closing of the door D by the door opener 32 and coating of the door D by the coating head 31, the inside and outside of the door D can be continuously coated. According to this work procedure, the time required for painting the door D can be shortened compared to the conventional art.

Also, each arm 3 is provided with an encoder 33 . An electrical signal emitted by the encoder 33 is input to the control device 4 . The control device 4 can recognize the current position of each arm 3 based on the electrical signal emitted by the encoder 33 .

The control device 4 is configured to be able to control the operations of the base 2, each arm 3, and the painting head 31 and door opener 32. The control device 4 is configured as a known computer, and includes a computing device such as a CPU, a storage device such as a hard disk, an output device such as a display, an input device such as a keyboard, and a communication device such as a LAN module. components.

[Control of painting robot]
Next, control of each part of the coating robot 1 will be described. (1) overmist adhesion avoidance control, (2) interference avoidance control, (3) overspray avoidance control, (4) teaching data correction, (5) overload detection, and (6) cleaning control, which will be described below, Both are executed by the controller 4 . Note that each of the controls (1) to (6) can be executed simultaneously as long as they are not contradictory.

(1) Overmist adhesion avoidance control The movement of each of the three arms 3 can be controlled so as not to allow the other arm 3 to enter. In other words, the control device 4 sets an entry prohibition area corresponding to each coating head 31 and controls the other arms 3 so as not to enter the entry prohibition area. Here, the no-entry area corresponding to a certain painting head 31 is, for example, a straight line connecting the ejection port of the painting head 31 and the target point where the paint ejected from the painting head 31 is to land. It can be in the range of 50 mm on each side.

(2) Interference Avoidance Control The control device 4 can control the motion of each of the three arms 3 within a range in which each arm 3 does not interfere with other objects. Here, examples of other objects include other arms 3, vehicle body V, other painting robots, structures in the painting booth, and the like.

As a first example, control for avoiding interference can be executed based on a signal input from the encoder 33. The control device 4 can recognize the current positions of the respective arms 3 based on the electrical signals emitted by the three encoders 33, and thereby can perform control considering the current positions of the respective arms 3. FIG. For example, when recognizing that another arm 3 exists in a predetermined range around a certain arm 3, the control device 4 performs control to stop the entire operation of the painting robot 1. FIG. This indicates that the positional relationship of the arms 3 recognized based on the signal input from the encoder 33 may cause interference between one arm 3 and another arm 3 if the operation of the arm 3 continues. It is from. Similarly, interference between the arm 3 and other objects such as the vehicle body V can also be avoided. By recognizing the current position of the arm 3 by the encoder 33 in this manner, interference between the arm 3 and other objects can be prevented.

As a second example, control for avoiding interference can be performed based on image data of the three arms 3 captured. In this example, image data captured by a camera (not shown) including the three arms 3 and the vehicle body V in the capturing range is input to the control device 4, and the control device 4 controls the three arms 3 based on the image data. Control each action. For example, when the distance between the arms 3 or the distance between the arms 3 and the vehicle body V in the image data is smaller than a predetermined threshold value, it is determined that there is a risk of interference, and the arms 3 are moved in the direction to increase the distance. Control to operate.

As a third example, the control for avoiding interference is based on the dimensional information of the vehicle body V, the dimensional information of each part of the painting robot 1, and the information of the movable range of each part of the painting robot 1, which are input in the control device 4 in advance. , the current value of the control amount of each part of the painting robot 1, and other information. For example, based on the dimensional information of each part and the current value of the control amount of each part of the painting robot 1, the distance between the arms 3 and the distance between the arm 3 and the vehicle body V can be calculated. may perform control to avoid interference based on.

Also, in any of the first to third examples, in addition to controlling the operation of the arm 3, recording, displaying, and transmitting information related to the executed control may be performed. In this case, the controller 4 may be provided with devices corresponding to the operations to be performed (such as recording, displaying and transmitting information). Information related to control may include, but is not limited to, the posture of the coating robot 1, the position, distance, and direction of each arm 3, the position of the object to be coated, various operating parameters, time, and image data.

(3) Overspray Avoidance Control The control device 4 can control the operation of each of the three arms 3 so that the distance between the painting head 31 and the vehicle body V is within a range where the painting head 31 does not overspray. Specifically, the range of the separation distance from the object to be coated in which overspray does not occur (hereinafter referred to as the appropriate range) is determined by the specifications (model, model number, etc.) of the coating head 31. Each operation of the three arms 3 is controlled so that the distance from the vehicle body V is within an appropriate range. Here, the current value of the distance between the painting head 31 and the vehicle body V can be obtained from the second example (method using image data) and the third example (method of calculating based on the control amount, etc.) of (2) above. can be determined by the method of The specifications and appropriate ranges of the first coating head 31A and the second coating head 31B currently attached to the first arm 3A and the second arm 3B are stored in the storage device of the controller 4 in advance.

(4) Correction of Teaching Data The control device 4 can correct the teaching data related to the control of the three arms 3 based on the image data of the three arms 3 captured.

Each part of the painting robot 1 is controlled by a control device 4 that executes a teaching program. A teaching program contains one or more teaching data. Each teaching data represents a unit operation to be taken by the coating robot 1, and includes, for example, information specifying coordinates of a point to be moved by the arm 3 in the unit operation, information specifying the speed of the movement, and information specifying the speed of the movement. Information specifying the operation of the coating head 31 is included.

Although the teaching data is set so that the desired painting is applied to the vehicle body V, the operation of the painting robot according to the teaching data may differ from the originally intended operation due to various factors. Therefore, in this embodiment, the teaching data related to the control of the three arms 3 can be corrected based on the image data obtained by photographing the three arms 3 . Specifically, for example, on the image data, the trajectory of the painting head 31 in the originally intended operation is compared with the trajectory of the painting head 31 that is actually photographed, and the teaching data is corrected so that the difference is eliminated. do. The correction of the teaching data may be performed autonomously by the control device 4, or may be manually performed based on the input operation by the operator.

(5) Overload Detection The control device 4 can determine that the base 2 is overloaded when the load detected by the load sensor 21 exceeds a predetermined threshold. For example, when all three arms 3 are biased toward the front of the vehicle body V (right side in FIG. 1) with respect to the base 2, the load sensor 21 rotates the base 2 forward of the vehicle body V. Detects the load that acts to make it fall down.

The load with which the control device 4 determines whether or not there is an overload may be the absolute value of the load detected by the load sensor 21, or may be based on consideration of the direction of the load. For example, if the presence or absence of an overload is determined based on the horizontal component of the load detected by the load sensor 21, it is easy to detect a defect (overload) in which the arm 3 is unevenly distributed as illustrated above. .

It should be noted that when the control device 4 determines that the base 2 is overloaded, information related to the overload may be recorded, displayed, transmitted, and the like. In this case, the controller 4 may be provided with devices corresponding to the operations to be performed (such as recording, displaying and transmitting information). The overload information may include, but is not limited to, the value and direction of the detected load, the attitude of the painting robot 1, various operating parameters, time, and image data.

(6) Cleaning control The control device 4 guides the two coating heads 31 (the first coating head 31A and the second coating head 31B) one by one to the cleaning device when cleaning the coating heads 31. It controls two arms 3 (first arm 3A, second arm 3B).

For example, in the painting robot 1 shown in FIG. 1, the first arm 3A (first painting head 31A) is mainly in charge of painting the front half of the vehicle body V, and the second arm 3B (second painting head 31B) is in charge of painting the vehicle body. Assume that you are mainly in charge of painting the rear half of the V. Here, if the painting of the front half of the vehicle body V is completed prior to the painting of the rear half of the vehicle body V, the painting that the first painting head 31A is in charge of is completed, but the second painting head 31B is in charge of it. A situation arises in which the paint still remains. At this time, the control device 4 controls the second arm 3B so that the second coating head 31B continues coating, and guides the first arm 3A to a cleaning device (not shown) for the first coating head 31A. to control. As a result, the cleaning of the first coating head 31A can be carried out while continuing the coating by the second coating head 31B. After that, the second arm 3B is controlled to be guided to the cleaning device of the second coating head 31B after the coating of which the second coating head 31B is in charge is completed. With this configuration, the number of cleaning devices required to clean the two coating heads 31 can be minimized without waiting for cleaning.

[Action and effect of the painting robot]
According to the painting robot 1 according to this embodiment, the number of painting robots to be installed can be reduced compared to the case of using a conventional painting robot having only a single arm. Also, when installing a plurality of painting robots, it is necessary to provide an appropriate separation distance so that different individual painting robots do not interfere with each other. Since the number itself can be reduced, the number of locations where separation distances need to be provided is reduced. As a result, the total extension of the painting line can be shortened compared to the conventional one.

Furthermore, it is also possible to integrate the painting process, which was previously designed as a separate process. For example, the separate steps of coating the outer plate and the inner plate can be combined into a step of painting the outer plate and the inner plate in parallel.

[Other embodiments]
Finally, another embodiment of the coating robot according to the present invention will be described. It should be noted that the configurations disclosed in the respective embodiments below can also be applied in combination with configurations disclosed in other embodiments unless there is a contradiction.

The place where the painting robot according to the present invention is installed is not limited, and can be a floor surface, a wall surface, a ceiling surface, or the like. Moreover, the painting robot according to the present invention may be configured to be movable. For example, it may be configured so as to be able to run on rails provided in the painting booth.

The number of arms is not limited in the painting robot according to the present invention. The number of arms can be, for example, 2-4. Also, the number of axes of each arm is not particularly limited. The number of axes of a plurality of arms may be the same or different from each other.

In the above embodiment, the configuration in which the three arms 3 are respectively provided with the first painting head 31A, the second painting head 31B, and the door opener 32 has been described as an example. However, the work devices provided on the plurality of arms in the coating robot according to the present invention are not limited as long as at least one arm has a coating head. Working devices that can be provided on the arm include a coating head, a door opener, a camera, a surface thermometer, a non-contact paint solids (NV) meter, a non-contact film thickness meter (wet paint film thickness meter), and the like. Examples include, but are not limited to.

In the above embodiment, each arm 3 is provided with an encoder 33, and an example in which interference avoidance control is performed based on the electrical signal output from the encoder 33 has been described. However, in the present invention, the method for controlling each arm so as not to interfere with another object is not limited to the above. For example, a configuration may be employed in which each arm is provided with a proximity sensor, and based on the reaction of the proximity sensor, the existence of another object that may interfere with the surroundings of the arm is recognized.

Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects, and that the scope of the present invention is not limited by them. Those skilled in the art will easily understand that modifications can be made as appropriate without departing from the scope of the present invention. Therefore, other embodiments modified without departing from the gist of the present invention are naturally included in the scope of the present invention.

The present invention can be used, for example, for painting car bodies.

REFERENCE SIGNS LIST 1: painting robot 2: base 21: load sensor 3: arm 3A: first arm 3B: second arm 3C: third arm 31: painting head 31A: first painting head 31B: second painting head 32: door opener 33 : Encoder 4: Control device V: Vehicle body D: Door

Claims (10)

a base, a plurality of arms extending from the base, and a controller;
At least one of the plurality of arms has a coating head with a high coating rate. The coating robot according to claim 1, wherein the coating head has a coating rate such that 90% or more of the coating discharged from the coating head adheres to the object to be coated. The controller controls the plurality of arms so as not to allow other arms to enter a range where the overmist of the paint discharged from the coating head reaches and a range separated from the range by a predetermined distance or less. 3. The painting robot according to claim 1 or 2, which is constructed so as to be able to control each operation of the. The control device is configured to be able to control the motion of each of the plurality of arms so that the distance between the coating head and the object to be coated is within a range in which the coating head does not overspray. 4. The coating robot according to any one of 1 to 3. The painting robot according to any one of claims 1 to 4, wherein the control device is configured to be able to control the motion of each of the plurality of arms within a range in which each of the arms does not interfere with other objects. . each of the plurality of arms has an encoder;
6. The coating robot according to claim 5, wherein said control device is configured to be able to control the motion of each of said plurality of arms based on the electrical signal emitted by said encoder. The painting robot according to claim 5 or 6, wherein the control device is configured to be able to control the motion of each of the plurality of arms based on image data obtained by photographing the plurality of arms. The coating according to any one of claims 1 to 7, wherein the control device is configured to be able to correct teaching data relating to control of the plurality of arms based on image data obtained by photographing the plurality of arms. robot. The base has a load sensor capable of detecting a load received by the base,
The painting robot according to any one of claims 1 to 8, wherein the control device can determine that the base is overloaded when the load exceeds a predetermined threshold. at least two of the plurality of arms have the painting head;
10. The control device according to any one of claims 1 to 9, wherein the control device controls the plurality of arms so as to sequentially guide the plurality of coating heads one by one to the cleaning device when cleaning the coating heads. painting robot.

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