JP3285694B2 - Automatic welding apparatus and welding method using the automatic welding apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic welding apparatus for performing welding on the basis of position data detected by a sensor using a welding torch attached to a distal end of a movable body such as a robot arm.

[0002]

2. Description of the Related Art Conventional automatic welding devices of this type include:
For example, those shown in FIGS. 8 and 9 are known.
In such an automatic welding device 1, a sensor device 4 and a welding torch 5 are attached to the tip of a movable arm 3 disposed on a base 2.
Are arranged.

In the automatic welding apparatus 1, a welding reference position at which welding is performed and a sensor measurement position at which scanning and measurement are performed by the sensor device 4 are previously learned and stored in an internal central control device.

[0004] Based on the welding reference position and the sensor measurement position, the sensor device 4 detects a position difference between the structure 7 as a workpiece to be welded positioned on the feed line 6 and the welding reference position. Based on the position correction data, the central control device corrects the position difference between the stored welding reference position and the detected welding position based on the position correction data, and corrects the position difference between the column 7a and the beam 7b of the structure 7. On the other hand, the welding torch 5 is configured to perform welding.

[0005] As a welding robot provided with this type of sensor, there is known a welding robot described in "Mechatronics System Encyclopedia", pp. 595-601, etc., published by the Industrial Research Institute Publishing Division. I have.

[0006]

However, in such a conventional apparatus, as shown in FIG. 9, in order to determine a place for performing measurement by scanning with the sensor device 4, a reference point is determined in advance. Relative position from 1 (ORG) to point 2 (XX) indicating depth, and point 1 (ORG)
An operator traces the relative position from to the point 3 indicating the lateral width to the scanning position of the structure using the structure 7 on the feed line 6 and stores the relative position in the central controller of the welding robot 1. Will be

The work of storing the welding reference position is also performed by the operator using the structure 7 on the feed line 6 to trace the welding position of the structure.

For this reason, while storing such information,
The work must be performed with the feed line 6 stopped. For example, when a structure having a different shape from the structure 7 flows on the feed line subsequent to the structure 7, when a structure having a different shape at the head once comes before the welding robot 1, In each case, the feed line 6 must be stopped and welding position information and the like must be stored, and work on other feed lines 6 is stagnated. In particular, it is inconvenient when one feed line 6 is used for small-volume production of other products. There is a similar problem when replacing the welding equipment.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic welding apparatus having good working efficiency without stopping a feed line while storing welding position information and the like.

[0010]

According to the first aspect of the present invention, a welding torch and a position of a portion to be welded are detected by a three-dimensionally driven moving arm. An automatic welding apparatus for performing a teaching operation on the object to be taught and then welding a portion to be welded on the object to be welded, wherein a feed line for setting the object to be welded is provided, and a feed line outside the feed line is provided. In addition to providing an arrangement portion for setting the object to be taught, the object to be taught has a simulated welding scheduled portion having the same shape as the welding scheduled portion of the workpiece, and the moving arm portion includes the welding torch and the sensor. It is characterized by an automatic welding device that is capable of reciprocating between an object to be welded and the object to be taught.

According to the second aspect of the present invention, the moving arm portion includes a base portion that enables the welding torch and the sensor to reciprocate between the workpiece and the teaching target; 2. The automatic welding apparatus according to claim 1, further comprising: a movable arm on which a torch and a sensor are provided, wherein only the coordinate value of the movable arm is used when calculating the coordinate value of the moving arm. And

[0012] According to the third aspect,
While the workpiece is provided on the feed line, an arrangement portion for setting the workpiece is provided outside the feed line, and the tip of the welding torch is applied to a portion to be simulated to be welded on the workpiece, and the coordinates of the moving arm are provided. A welding torch initial setting teaching step of detecting a welding torch teaching data by detecting a value, a welding reference point calculating step of calculating a welding reference point of a simulated welding scheduled part of the object to be taught from the welding torch teaching data, and the sensor Is directed to a simulated welding scheduled portion of the object to be taught, the outer shape of the simulated welding scheduled portion of the taught object is measured by the sensor, and first sensor teaching data is obtained from the coordinate value of the moving arm and the measured value of the sensor. A first teaching step to a sensor for obtaining the following, a simulated welding point calculating step of calculating a coordinate value of a simulated welding point of a simulated welding scheduled part of the object to be taught based on the first sensor teaching data, Head of department Moving the tip of the moving arm from the object to be welded to the object to be welded, and measuring the outer shape of the portion to be welded of the object to be welded with the sensor, and using the coordinate values of the moving arm and the measurement data of the sensor. A second teaching step to the sensor for obtaining the second sensor teaching data, a welding point calculating step of calculating a coordinate value of a welding scheduled point of the workpiece based on the second sensor teaching data, Comparing the coordinate value and the coordinate value of the simulated welding point, and a correction data calculating step of calculating the difference between the coordinate value of the simulated welding point and the coordinate value of the welding point as correction data, based on the correction data,
A welding torch operation data calculating step of calculating a coordinate value of a moving arm corresponding to a state in which the welding torch is applied to a portion to be welded of the work to be welded; and A welding method using the automatic welding apparatus according to claim 1 or 2, which has an actual welding step of performing an operation corresponding to (1) and performing welding.

[0013]

According to the first aspect of the present invention, the object to be taught is provided on the arrangement portion outside the feed line. Since the object to be taught is provided with a simulated welding scheduled part having the same shape as the part to be welded of the object to be welded, the teaching is performed with the moving arm portion directed toward the object to be taught. By welding the parts of the workpiece to be welded,
You can work without stopping the line while teaching.

According to the second aspect of the present invention, of the coordinate values for performing the teaching with the moving arm toward the object to be taught, only the coordinate value of the movable arm is used. Since the coordinate value of the arm is calculated, the coordinate value of the base portion used for reciprocating movement between the workpiece and the taught portion is excluded, and the coordinate value of the workpiece on the line is left as it is. It is possible to weld the parts to be welded.

According to the third aspect of the present invention, in the initial setting teaching step of the welding torch, the tip of the welding torch is applied to the simulated welding scheduled portion of the object to be taught, and By detecting the coordinate values, welding torch teaching data is obtained.

In the welding reference point calculating step, a welding reference point of a simulated welding scheduled portion of the object to be taught is calculated from the welding torch teaching data.

In a first teaching step to the sensor, the sensor is pointed at a portion to be simulated to be welded on the object to be taught, and the outer shape of the portion to be simulated to be welded to the object to be taught is measured by the sensor. The first sensor teaching data is obtained from the value and the measured value of the sensor.

In the simulated welding point calculation step, coordinate values of the simulated welding point of the simulated welding scheduled portion of the object to be taught are calculated based on the first sensor teaching data.

In the moving arm tip moving step, the tip of the moving arm is directed from the object to be taught to the object to be welded.

In the second teaching step to the sensor, the outer shape of the portion to be welded of the workpiece is measured by the sensor, and the second sensor teaching is performed based on the coordinate value of the moving arm and the measurement data of the sensor. Data is obtained.

In the welding point calculation step, coordinate values of a welding scheduled point of the workpiece are calculated based on the second sensor teaching data.

In the correction data calculating step, the coordinate value of the welding location and the coordinate value of the simulation welding location are compared, and the difference between the coordinate value of the welding location and the coordinate value of the simulation welding location is calculated as correction data.

In the welding torch operation data calculating step, a coordinate value of a moving arm corresponding to a state where the welding torch is applied to a portion to be welded on the workpiece is calculated based on the correction data.

In the actual welding process, an operation of applying a welding torch to a welding location is performed based on the welding torch operation data, and welding is performed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 to 7 show an embodiment of the present invention. The same or equivalent parts as those in the conventional example are denoted by the same reference numerals.

First, the structure will be described.
1 shows a welding robot as an automatic welding apparatus according to this embodiment. The welding robot 11 is provided with a three-dimensionally driven moving arm 11a. The moving arm portion 11a mainly includes a movable arm 3 that can be driven in a predetermined direction, and a base movement that enables the movable arm 3 to reciprocate between the structure 7 to be welded and the object 17 to be taught. And a part 12. The welding torch 5 for welding a portion of the workpiece to be welded and a sensor device 4 as a sensor are disposed at the tip of the movable arm 3. In addition, the base unit 12 includes:
The movable arm 3 is rotatably supported on the pedestal 2 and has a built-in drive mechanism including a drive motor for rotating the movable arm 3 to a predetermined angle.

The sensor device 4 mainly includes an irradiation unit and a light receiving unit. Then, the laser beam 10 emitted from the irradiating section is reflected around the portion to be welded 14b of the structure 7 as an object to be measured, and the reflected laser beam is detected by the light receiving section and It is configured to detect the position to be welded. The sensor controller 4 is connected to a sensor controller 13. Then, the shape data of the structure 7 detected by the sensor device 4 is transmitted to the sensor controller 13.

The sensor controller 13 receives the shape data and receives the pillars 7a and the beams 7b constituting the structure 7.
G between the joint pipe 7c and the step D,
A coordinate calculating means for calculating coordinate values such as an edge E; an optimum condition selecting means for selecting an optimum welding condition from the shape data from an optimum welding condition database stored in advance by the welding robot 11; And a signal transmitting means for transmitting the coordinates of the portion to be welded and the optimal welding condition signal. And this sensor controller 1
3 is connected to the central control device of the welding robot 11.

The optimal welding condition database in the central control unit of the welding robot 11 contains information such as current, voltage, speed, torch angle, and target angle for determining welding conditions based on the knowledge and experience of skilled workers. It is remembered. When calculating the coordinate value of the moving arm 11a, the coordinate value is calculated using only the coordinate value of the movable arm 3.

The feed line 6 is constituted by conveying means such as a belt conveyer, so that the conveying speed can be adjusted according to the operation.

Outside the feed line 6, an arrangement portion 18 is provided as a position where the structure 7 on the feed line 6 does not interfere when the structure 7 is sent. An initial setting structure 17 as an object to be taught is set and prepared in the arrangement portion 18. The structure 17 for initial setting is placed in a state where the structure 7 on the feed line is rotated 90 ° in the horizontal direction so that the surface facing the welding robot 11 is the same surface. The structure 17 for initial setting includes the structure 7
And a column 7a to be welded, and this column 7a
And a joint pipe 7c used for joining the beam and the beam 7b.

The column 7a and the joint pipe 7
A portion to be simulated to be welded 14a is provided around the joint surface with c. The simulated welding scheduled portion 14a is set substantially along a welding reference line 14, which is a welding reference point.

After teaching is performed with the initial setting structure 17, a portion 1 to be welded of the structure 7 is to be welded.
4b is welded.

The operation of the present invention thus configured will be described. First, according to the work process flowchart shown in FIG. 7, after starting each function of the welding robot 11, the base arm 12 rotates the movable arm 3 of the welding robot 11 by about 90 °, The moving arm portion 11a is rotated and moved to a position (position indicated by a two-dot chain line in FIG. 1) of the arrangement portion 18 outside the feed line 6 and separated from the feed line 6.

At the position of the disposing portion 18, an initial setting structure 17 having substantially the same shape as the structure 7 is previously arranged.
It is installed in. This initialization structure 17 is shown in FIG.
In order to determine the place where measurement is performed by scanning with the sensor device 4 as shown in FIG.
And the relative position from the point 1 (ORG) to the point 3 indicating the width is the same as the relative position of the structure 7 on the feed line 6. It is formed so that it becomes.

By measuring the points 1 to 3 at the position of the arrangement portion 18 outside the feed line 6, the measurement positions of the sensors and the reference positions of the welding are stored.

That is, in the initial setting teaching process of the welding torch 5 in step 1, the tip 5a of the welding torch 5 is applied to the simulated welding scheduled portion 14a of the initial setting structure 17, and is along the welding line. When the tip 5a is manually moved, the coordinate value of the moving arm 11a is detected to obtain welding torch teaching data.

In the step 2 for calculating the welding reference point,
From the welding torch teaching data, the central processing unit calculates the welding reference point of the simulated welding scheduled portion 14a of the initial setting structure 17.

In the first teaching step for the sensor in step 3, the sensor device 4 is directed toward the simulated welding scheduled portion 14 a of the initial setting structure 17, and the sensor device 4 simulates the initial setting structure 17. The shape of the portion to be welded 14a is measured, and first sensor teaching data is obtained from the coordinate value of the moving arm 11a and the measurement value of the sensor device 4.

In the step 4 for calculating the simulated welding position,
Based on the first sensor teaching data, the coordinate value of the simulated welding location of the simulated welding scheduled portion 14a of the initial setting structure 17 is calculated.

During this time, the structure 7 on the feed line 6
Is flowing, so that a certain interval is provided between the structures 7, 7 so as not to stop the flow, or
If the interval is short, other welding robots or workers
The welding work may be performed only for the structure 7 flowing during this time.

Next, the base arm 12 rotates the movable arm 3 back to the welding position indicated by the solid line in FIG. 1 and performs position detection and welding on the structure 7 on the feed line 6. Do.

In the moving arm tip movement step of step 5, the tip of the moving arm 11a is directed from the initial setting structure 17 as the object to be taught to the structure 7 as the object to be welded.

In the second teaching step for the sensor in step 6, the outer shape of the portion to be welded of the structure 7 is measured by the sensor device 4, and the coordinate value of the moving arm 11a and the measurement data of this sensor device are obtained. , The second sensor teaching data is obtained.

First, as shown in FIG. 3, the movable arm 3 is operated to move the sensor device 4 to the sensor measurement positions S1 to S7.
Scanning is performed while moving sequentially to At this time, a point 2 (XX) indicating a depth from a point 1 (ORG) serving as a reference measured by the initial setting structure 17.
These sensor measurement positions S1 to S7 are determined on the basis of the relative position up to and the relative position from point 1 (ORG) to point 3 indicating the width.

At this time, of the coordinate values for teaching the moving arm 11a toward the initial setting structure 17, only the coordinate of the movable arm 3 is used to calculate the coordinate of the moving arm 11a. Is calculated, the coordinate value of the base unit 12 used for reciprocation between the structure 7 and the initialization structure 17 is removed, and the structure on the feed line 6 is left as it is. 7 is scanned.

Next, once the movable arm 3 returns to the standby position, the sensor controller 13 determines that the welding target portion 14b
And a position difference between the reference position and the welding reference position stored in advance, position correction data is created, coordinate values of the welding position are determined, and optimum welding condition signals are determined. Send to control device.

That is, in the welding location calculation step of step 7, the structure 7 is determined based on the second sensor teaching data.
Are calculated for the welding scheduled portion 14b.

In the correction data calculating step of step 8, the coordinate value of the welding location is compared with the coordinate value of the simulated welding location.
The difference between the coordinate value of the welding location and the coordinate value of the simulated welding location is calculated as correction data. At this time, of the coordinate values of the simulated welding scheduled portion 14a when teaching the moving arm 11a toward the initial setting structure 17, only the coordinate value of the movable arm 3 is used. 11
Since the coordinate value of “a” is calculated, the coordinate value of the base unit 12 used for reciprocating motion between the structure 7 and the structure 17 for initial setting is excluded, and the movable arm 3 is left as it is. Is applied to the portion to be welded 14b of the structure 7 and corrected using the same coordinate values of the moving arm 11a as when the tip 5a was manually moved along the welding reference line 14 to be welded. A day is created.

In the central control unit of the welding robot 11, based on these signals, the welding torch 5 disposed at the tip of the movable arm 3 is moved to a welding reference line 14 of a portion 14b to be welded as shown in FIG. Are sequentially moved while correcting the positional deviation along the line, and the space between the column 7a and the beam 7b of the structure 7 is welded.

That is, in the welding torch operation data calculation step of step 9, based on the correction data, the coordinates of the moving arm portion 11a corresponding to the state where the welding torch 5 is applied to the scheduled welding portion 14b of the structure 7 A value is calculated.
These coordinate values become welding torch operation data.

In the actual welding process in step 10, an operation of applying the welding torch 5 to the welding location is performed based on the welding torch operation data, and welding is performed. At this time, the optimum conditions for the welding are selected by the optimum condition selecting means of the sensor controller 13, the gap and the like are corrected, and accurate welding is performed.

Then, returning to step 6 again, in the second teaching step for the sensor, the outer shape of the portion to be welded of the structure 7 to be sent next is measured by the sensor device 4.

For this reason, the initial setting of the welding robot 11 is performed while moving the structures 7 without stopping the feed line 6 while storing the welding position information such as the sensor measurement position and the welding reference position. Can be done. For example,
Even if another structure having a shape different from that of the structure 7 flows on the same feed line 6 following the structure 7, the feed line 6 is stopped as in the conventional case each time, and the step of FIG. It is not necessary to perform the initial setting teaching process of the welding torch 5 shown in FIG. Therefore, an efficient line operation can be performed even in the case of high-mix low-volume production, and an automatic welding apparatus with good operation efficiency can be provided.

Further, in the welding robot 11 of this embodiment, the tip 5a of the movable arm 3 is applied to the simulated welding scheduled portion 14a of the initial setting structure 17 as it is.
Since the correction data is created using the coordinate values of the moving arm 11a when the tip 5a is manually moved along the line to be welded, an automatic welding device with a simpler configuration and good working efficiency is provided. Can be provided.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention is applicable even if there is a design change within the scope of the present invention. include. For example, in the above-described embodiment, using the base unit 12 including a driving mechanism such as a driving motor,
Arrangement part 1 outside the feed line 6 from the welding position to the movable arm 3
Although the rotation is automatically performed up to 8, the rotation is not particularly limited thereto. For example, only the rotation axis may be provided between the movable arm 3 and the pedestal 2 and the rotation may be performed manually.

Further, the position of the disposition portion 18 is set to a position obtained by rotating the movable arm 3 by 90 ° from the welding position on the feed line 6;
It goes without saying that any other angle or position, such as a position rotated to another angle, or a position above the welding robot 11, may be a position outside the feed line 6. .

In the above embodiment, the movable arm 3 can be driven in a predetermined direction. However, the present invention is not limited to this. For example, the movable arm 3 can be driven by a combination of linear actuator movements in the XY directions and the like. The movable arm 3 may be moved in any manner, for example, the movable arm 3 may be driven.

In the above embodiment, the initial setting structure 17 as the object to be taught is a column 7a to be welded, which is a part of the structure 7, and a connection between the column 7a and the beam 7b. However, the present invention is not particularly limited to this. For example, when the entire structure 7 is used or other parts are welded, a partial cut model of the other parts is used. Of course, it may be.

In the correction data calculation step of the step 8, when calculating the coordinate value of the moving arm portion 11a, only the coordinate value of the movable arm 3 is used. The coordinate value of the simulated welding point is compared with the coordinate value of the simulated welding point, and if any difference between the coordinate value of the simulated welding point and the coordinate value of the simulated welding point is calculated as correction data, Is also good.

[0062]

As described above, according to the first aspect of the present invention, after the moving arm is taught toward the object to be taught, the welding on the line is performed. By welding the parts to be welded, it is possible to work without stopping the line even during teaching. For this reason, it is possible to provide an automatic welding apparatus with good work efficiency without stopping the feed line while storing welding position information and the like.

According to the second aspect of the present invention, only the coordinate value of the movable arm is used by using only the coordinate value of the movable arm among the coordinate values when teaching the moving arm portion toward the object to be taught. Since the coordinate value of the arm is calculated, the coordinate value of the base portion used for reciprocation between the workpiece and the taught portion is excluded, and the teaching is performed with the workpiece as it is. Can be used to weld the portion to be welded of the workpiece on the line using exactly the same coordinate values. For this reason, it is possible to provide an automatic welding apparatus having a good working efficiency with a simple configuration and without stopping the feed line even while storing welding position information and the like.

According to the third aspect of the present invention, the initial setting teaching step of the welding torch and the first instruction to the sensor are performed.
Is performed at the portion of the object to be simulated to be simulated.

Since the object to be taught is set on the arrangement portion outside the feed line, other operations can be performed without stopping the feed line even during each of the above-mentioned steps, and the work efficiency is good. Automatic welding equipment can be provided,
It has a practically useful effect.

[Brief description of the drawings]

FIG. 1 is a top view showing a welding robot according to an embodiment of the present invention and showing an arrangement of an entire system.

FIG. 2 is a top view of an initialization structure as an object to be taught arranged in the arrangement section of the same embodiment.

FIG. 3 is a perspective view of a system showing a welding robot of the same embodiment and showing a state where scanning is performed by a sensor device.

FIG. 4 is a perspective view of a system showing the welding robot of the same embodiment and showing a state where welding is performed with a welding torch.

FIG. 5 is a side view of a main part of the structure of the same embodiment.

FIG. 6 is a perspective view of a main part of the structure of the same embodiment.

FIG. 7 is a flowchart showing the working steps of the same embodiment.

FIG. 8 is a top view of the entire system, showing a conventional welding robot.

FIG. 9 is a top view of a main part of a structure on a feed line in a conventional example.

[Explanation of symbols]

 4 Sensor device (sensor) 5 Welding torch 6 Feed line 7 Structure (workpiece) 11 Welding robot (automatic welding equipment) 11a Moving arm 12 Base unit 17 Initial setting structure (workpiece) 14a Simulated welding Planned part 14b Planned part to be welded

Claims (3)

(57) [Claims] A welding arm and a sensor for detecting a position of a portion to be welded are provided on a moving arm portion driven three-dimensionally. An automatic welding apparatus for welding the object to be welded, wherein a feed line for setting the object to be welded is provided, and an arrangement portion for setting the object to be taught is provided outside the feed line. It has a simulated welding scheduled part having the same shape as the welding scheduled part, and the moving arm is capable of reciprocating the welding torch and the sensor between the workpiece and the taught object. Automatic welding equipment. And a movable arm provided with the welding torch and the sensor so that the welding torch and the sensor can reciprocate between the workpiece and the teaching object. 2. The automatic welding apparatus according to claim 1, wherein when calculating the coordinate value of the moving arm, only the coordinate value of the movable arm is used. 3. An object to be welded is provided on a feed line, and an arrangement portion for setting an object to be taught is provided outside the feed line. The tip of the welding torch is applied to a simulated welding scheduled portion of the object to be taught, and A welding torch initial setting teaching step of detecting coordinate values of the moving arm to obtain welding torch teaching data; and a welding reference point calculation for calculating a welding reference point of a simulated welding scheduled portion of the workpiece from the welding torch teaching data. A step of directing the sensor toward a simulated welding scheduled portion of the object to be taught, and measuring an outer shape of the simulated welding scheduled portion of the taught object by the sensor. 1
A first teaching step to a sensor that obtains the sensor teaching data of: a simulated welding point calculating step of calculating a coordinate value of a simulated welding point of a simulated welding scheduled part of the object to be taught based on the first sensor teaching data; A moving arm tip moving step of directing the tip of the moving arm from the object to be welded to the work to be welded; measuring the outer shape of a portion to be welded of the work to be welded by the sensor; A second teaching step to a sensor for obtaining second sensor teaching data from the measurement data of the sensor, and a welding point for calculating a coordinate value of a welding scheduled point of the workpiece based on the second sensor teaching data The calculation process compares the coordinate value of the welding location with the coordinate value of the simulated welding location,
A correction data calculating step of calculating, as correction data, a difference between the coordinate value of the simulated welding point and the coordinate value of the welding point, and a state in which the welding torch is applied to a portion of the workpiece to be welded based on the correction data A welding torch operation data calculating step of calculating a coordinate value of a moving arm portion corresponding to the following, and an actual welding step of performing an operation of applying a welding torch to a welding location based on the welding torch operation data to perform welding. A welding method using the automatic welding apparatus according to claim 1.