JP3022183B2 - Corrugated Welding Method for Corrugated Laminated Plate Welding Robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method for a welding robot for connecting corrugated lap joints for welding membranes each having a corrugated shape, and more particularly to a method for welding a corrugated portion.

[0002]

2. Description of the Related Art Conventionally, a contact type sensor for shape recognition is used for welding between corrugated membranes, and a torch angle control of a welding torch employs a copying control method. When a plasma arc welding method or the like, which is a high-speed welding method compared to the conventionally used TIG welding method, is applied to the welding between the membranes, when a welding torch or the like is operated by the copying control method in the corrugated portion,
The change of the torch angle could not follow the sensing of the contact type sensor, and it was easy to cause welding defects. Therefore, a delay control system has been proposed in which a sensor is provided ahead of the welding torch so that the welding torch can easily follow the welding torch.

[0003] Next, a description will be given of a welding robot using a delay control system in which this sensor is advanced so as to be applicable to a high-speed plasma arc welding method. FIG. 4 is a schematic perspective view, and FIG. 5 is a schematic plan view.

In FIGS. 4 and 5, reference numerals 1 and 2 denote corrugation-shaped membranes. Corrugation-shaped portions 1B and 2B are formed at predetermined pitches on plane portions 1A and 2A. The membranes 1 and 2 are formed by fitting the corrugation-shaped portions 1B and 2B in the up-down direction and overlapping the edges so that the corrugated laminated plate joints are long in the direction orthogonal to the direction of the corrugation-shaped portions 1B and 2B. The part 3 is formed. The edge position of the upper membrane 2 in the corrugated lap joint 3 forms a welding line 4. A guide rail 10 adjusted in a direction along the welding line 4 is disposed above the welding line 4, and the welding machine is supported and guided by the guide rail 10 and moves in the L direction along the welding line 4. A main body 11 is provided.

[0005] A welding torch 12 is attached to the welding machine body 11.
Is a horizontal direction W and a vertical direction H orthogonal to the welding line 4.
And is swingable in an arc direction と し た centered on a horizontal axis 16 parallel to the left-right direction W at the tip of the arc at the tip of the torch. Here welding torch 1
No. 2 employs a plasma arc welding method. Further, the welding machine body 11 is provided with a control device 13 for controlling the movement of the welding torch 12 in the horizontal direction W, the vertical direction H, and the swing in the arc direction Θ, and the control device 13 includes a delay circuit. It has a configuration. The welding machine body 11 also includes a visual sensor 14 for seam tracking measurement of a welding line at a position ahead of the welding torch 12 in the torch moving direction, and a laser displacement sensor for corrugation shape measurement at a side position of the visual sensor 14. 15 are provided.

[0006] A description will be given of the welding operation of the corrugated lap joint in the welding robot having the above configuration. The guide rail 10 is adjusted, and as shown in FIG.
1 is set so that the welding torch 12 and the visual sensor 14 are located above the welding line 4. At this time, the laser displacement sensor 15 is not located on the welding line 4, but there is no problem in recognizing the corrugation shape. However, the laser displacement sensor 15 needs to be provided at a position preceding the welding torch 12. By moving the welding machine main body 11 while being guided by the guide rail 10, the sensor 1
Plasma arc welding of the welding line 4 by the welding torch 12 is performed at a predetermined welding speed while performing the measurements by 4 and 15. At this time, the laser displacement sensor 15 senses the surface of the membrane 2 and the visual sensor 14 performs seam tracking of the welding line 14. The sensors 14 and 15 move ahead, and the welding torch 12 moves backward, but the delay is compensated for by the delay circuit incorporated in the control device 13 by the movement of the welding torch 12 in the horizontal direction W and the vertical direction H, The swing in the arc direction を around the center 16 is controlled with a time delay.

As shown in FIG. 6, the laser displacement sensor 15 performs normal sensing on the front plane area A of the plane section 2A, and when facing the rising slope area B of the corrugation shape section 2B, the laser displacement sensor 15 tilts. Due to the presence of the angle, the laser displacement sensor 15 cannot prompt the reflected light, so that the measurement becomes impossible. When the laser displacement sensor 15 faces the top area C, the state returns to a state in which reflected light is encouraged by the planar shape of the top, and measurement becomes possible. In the same manner, the measurement becomes impossible again when facing the falling slope range D, and the measurement becomes possible when facing the rear plane range a of the flat plate 2A. In such a state of measurement by the laser displacement sensor 15, the point at the highest position measured in the top range C is a point indicating the center position of the corrugation shape portion 2B. Here, the shape of the corrugation shape portion 2B is given to the control device 13 in advance, and the robot control software is set on the basis of the shape of the corrugation shape portion 2B with the position of the input highest point as a reference point. The NC data of the welding line 4 of the corrugated portion created when starting up is operated, and after a predetermined delay time, the welding torch 12 is operated with the NC data, thereby controlling the speed in the corrugation shape portion 2B and the vertical direction. H, and the swing control in the arc direction と し た about the horizontal axis 16, that is, the torch angle θ
Change can be controlled.

As shown in FIG. 7, the visual sensor 14 performs normal seam tracking on the front welding line range E of the welding line 4 with respect to the plane portions 1A and 2A, and performs a corrugation-shaped welding line range F. , The detection level is increased and the visual sensor 14 is out of the field of view, and the measurement becomes impossible. This non-measurable state is the entire region facing the corrugation-shaped portion welding line range F, and can be measured again when the visual sensor 14 faces the rear welding line range e. As described above, it is impossible to measure over the entire corrugation shape portion welding line range F. However, between the corrugation shape portion welding line range F and the two welding line ranges E and e in the vicinity thereof, the edge of the membrane 2 is almost equal. Since it is located in the vertical plane, the corrugation-shaped weld line range is located above a line connecting, for example, the coordinates of the starting point measured in the rising slope area B and the coordinates of the end point measured in the falling slope area D, for example. By taking the welding line 4 at F, the movement control of the welding torch 12 in the left-right direction W can be performed.

As described above, in the welding robot having the above-described configuration, the delay control method in which the sensor is advanced and the method of calculating the corrugation shape as NC data in advance are used. Also, the welding torch can sufficiently follow the welding line. Next, the operation of the welding torch 12 in the corrugated portion will be described in more detail.

As shown in FIG. 8, the corrugation shape includes an R1 portion forming a top portion, an R2 portion forming a slope portion,
R forming the rising and falling skirts
3 parts, the distance L from the center of the top to the starting point of the rising foot and the end of the falling foot, the height h of the top, and the thickness g of the membrane are provided, respectively, and the center points of three consecutive R parts and It is obtained by calculating those connection points. The plurality of types of corrugation shapes thus obtained are respectively recorded in the memory of the control device. One of the corrugation shapes is selected from the highest point of the corrugation shape detected by the sensing of the laser displacement sensor, and based on this shape, the corrugation portion created when the software for controlling the robot is started is created. N
C data is created.

Next, a description will be given of a method of calculating the NC data based on the shape of the selected corrugated portion. First, as shown in FIG. 9A, the Y-axis data for the X-axis data is calculated for each X-axis unit width as an arc on the plane coordinates. Then, the calculated values of the X-axis and the Y-axis are corrected according to a specific speed (movement amount per unit time) as shown in FIG. I do. Here, ○ indicates the data obtained in the first calculation, Δ
Marks indicate data obtained by correcting at a specific constant speed, and are equally spaced on a plane. Next, as shown in FIG. 9C, the respective torch angles θ are calculated based on the corrected data. The corrected data (x ₁ y ₁ ) to (x ₃ y
₃ ) Based on the torch angles θ ₁ and θ ₂ , the N of the corrugated part created when the robot control angle software is started
C data is created. The welding torch height is controlled so as to follow this, and the welding speed and the torch angle with respect to the welding line are controlled to be constant.

[0012]

As described above, in the case where the welding speed and the torch angle with respect to the welding line are controlled to be constant by the NC data of the corrugated portion created from the corrugated portion shape given in advance. However, welding defects occurred in the following places. (1) A place where the angle of the weld changes suddenly (2) A place where it is considered that heat remains due to welding and adversely affects the weld bead (3) By changing the installation direction of the membrane, Locations where welding conditions are different For example, as shown in FIG. 10, the locations where the angle of the welded portion rapidly changes include, as shown in FIG. There is an R portion of the portion 21, where the torch angle rapidly changes because the torch angle changes abruptly, causing a welding defect. As shown in FIG. 10, the location where the residual heat of (2) is likely to be concentrated has a small radius of curvature and radiates less heat with respect to the welding length than the flat portion. There is an R portion of the foot portion 20 and the falling foot portion 21,
In addition, since the welding torch moves while facing the same point, there is an R portion of the corrugated top 22 where heat is considered to be concentrated, and an arrowhead welding defect is likely to occur.

Further, as for the orientation of the membrane, as shown in FIG. 11, there are a bottom membrane 23, a ceiling membrane 24, and a side membrane 25. , The torch moves upward and downward 27 relative to the ceiling membrane 24, and the torch moves horizontally and vertically and horizontally relative to the side membrane 25, or the cubic moves vertically and vertically in the vertical direction. There is a direction 29, for example, in the vertical direction 29, the molten metal hangs down by its own weight at the top of the corrugation shape, thereby causing welding defects.

The present invention solves the above-mentioned problem. In welding between corrugated membranes, when welding a corrugated portion, a welding speed and a welding torch angle are appropriately controlled to obtain a good welding bead. It is an object of the present invention to provide a method for welding a corrugated portion in a welding robot for connecting a corrugated lap joint.

[0015]

In order to solve the above-mentioned problems, a method of welding a corrugated portion in a welding robot for splicing corrugated lap joints according to the present invention employs a delay control system in which a sensor precedes a welding robot and employs a corrugation shape. Is a corrugated portion welding method for a corrugated lap joint welding robot that calculates and welds in advance NC data as NC data, and the welding speed and welding are added to the NC data of the corrugated portion created when the robot control software is started. A parameter for arbitrarily changing the torch angle is added.
Gradually changes the torch angle shortly before reaching the point.
To change the torch angle smoothly, and the residual heat
In places where concentration occurs, increase the welding speed to
Welding speed and welding toe
The bead angle is controlled to obtain a good bead.
You. Also, by changing the mounting direction of the membrane
In places where welding conditions are different, the molten metal may
Adjust the welding speed and welding torch angle to prevent dripping.
To control welding speed and welding torch angle
It was done.

[0016]

According to the above configuration, for example, in the R portion of the corrugation-shaped foot portion where the angle of the welded portion changes rapidly,
Before the welding torch reaches the R portion, the torch angle is gradually changed within the range of the determined maximum angular velocity, so that the torch angle changes smoothly at the R portion, or the radius of curvature is small, The R portion of the corrugation-shaped foot portion that dissipates heat to the welding length less than the flat portion and the R portion of the corrugation-shaped top portion where the concentration of heat is likely to occur because the welding torch moves while facing the same point. In areas where the weight applied to the molten metal on the corrugated weld line differs by increasing the welding speed to reduce the heat input to the welding line, or by changing the membrane mounting direction, the molten metal is By adjusting the welding speed and welding torch angle to prevent dripping downward, To be able to properly control the welding speed and the welding torch angle that, it is possible to obtain a good weld bead.

[0017]

An embodiment of the present invention will be described below. FIG. 1 is a flow chart for explaining a method of welding a corrugated portion in a welding robot for splicing a corrugated lap joint according to an embodiment of the present invention. The main part of the method is a corrugated portion created when software for controlling a robot is started. Is to change the welding speed and the welding torch angle by adding parameters for the following items. (1) A place where the angle of the weld changes suddenly. (2) A place where it is considered that heat remains due to welding and adversely affects the weld bead. (3) A change in the mounting direction of the membrane causes a change in the other direction. Here, the parameters are a coefficient and a constant for arbitrarily changing a welding speed and a welding torch angle when welding an R portion of a corrugated portion where defects easily occur.

FIG. 2 is a diagram for explaining the control at a place where the angle of the welded portion changes suddenly or at a place where heat remains due to welding. In FIG. 2, at the R portion of the corrugation-shaped rising foot portion 20, the torch angle is gradually changed from before the welding torch reaches the R portion, whereby the torch angle at the R portion of the rising foot portion 20 is sharply increased. It avoids unusual changes and makes smooth changes. The angle change at this time is set to be performed within the range of the determined maximum angle. In addition, the radius of curvature of the R portion of the rising foot portion 20 is small, and the place where heat is dissipated with respect to the welding length is smaller than the flat portion. Therefore, the welding speed at this location is increased, and Heat input is reduced. This is the same in the R portion of the corrugated falling tail portion 21. Furthermore, at the R portion of the corrugated top 22,
Since the welding torch moves while pointing to the same point, heat is concentrated at this point, so that at this point at least the welding speed is increased to reduce the heat input to the welding line.
These operations are performed by adding parameters to the NC data of the corrugated section created when the robot control software is started. The parameters to be adjusted at this time are the welding speed, the torch angle, and the torch angular speed. The maximum value is set for the torch angular speed. This makes it possible to appropriately control the welding speed and the welding torch angle at the time of welding, and to prevent welding defects caused by the movement of the conventional welding torch.

FIG. 3 is a view for explaining control of welding in a location where welding conditions are different from other directions due to a change in the mounting direction of the membrane, particularly control in vertical welding.
In FIG. 3, the molten metal tends to hang downward due to its own weight at the corrugation-shaped top 22. Therefore, as shown in the figure, the welding torch angle is controlled to be slightly inclined and to move diagonally upward to arc the molten metal. To prevent the weld bead from sagging downward.
In addition, as shown in FIG. 11, the mounting direction of the membrane includes upward, downward, and sideways directions, and movement parameters such as the torch angle of the welding torch are selected for each direction of the membrane, including the upright position. For example, the direction is not automatically detected, but a number is selected by a rotary switch or the like provided in the robot control device, so that the robot is manually instructed to set a motion parameter for each direction.

[0020]

As described above, according to the present invention, a delay control system in which a sensor precedes a welding robot is employed, and when the corrugation shape is calculated as NC data in advance and the welding is performed, the angle of the welding portion is sharply increased. Welding speed and welding torch angle at locations that change, or that are considered to have an adverse effect on the weld bead due to residual heat due to welding, or where the orientation of the membrane changes and welding conditions differ from other directions. By changing the welding speed and welding torch angle in the corrugated part at the time of welding in addition to the NC data of the corrugated part created when the software for robot control is started. Good welding bead can be obtained, and the welding caused by the movement of the conventional welding torch Recessed can prevent.

[Brief description of the drawings]

FIG. 1 is a main part flow chart of a method for welding a corrugated portion in a welding robot for splicing a corrugated lap according to an embodiment of the present invention.

FIG. 2 is a view for explaining control in a place where the angle of the welded portion changes rapidly and a place where heat remains due to welding in the corrugated part welding method.

FIG. 3 is a view for explaining control in welding in a location where welding conditions are different from other directions by changing a mounting direction of a membrane in the corrugated portion welding method, particularly in vertical welding.

FIG. 4 is a schematic perspective view of a welding robot for splicing corrugated lap joints.

FIG. 5 is a schematic plan view of the welding robot for splicing corrugated lap boards.

FIG. 6 is a diagram illustrating a measurement state by a laser displacement sensor.

FIG. 7 is a diagram illustrating a measurement state by a visual sensor.

FIG. 8 is a view showing a shape of a corrugation-shaped portion and dimensions of a main portion thereof.

FIG. 9 is a diagram illustrating a method of calculating NC data of a corrugation shape portion.

FIG. 10 is a diagram illustrating a location where the angle of a weld changes rapidly and a location where heat remains due to welding.

FIG. 11 is a diagram illustrating a mounting direction of the membrane.

[Explanation of symbols]

 1, 2 membrane 3 corrugated overlap plate 4 welding line 11 welding line main body 12 welding torch 13 control unit 14 visual sensor 15 laser displacement sensor 20 rising foot 21 falling foot 22 top

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tateo Miyazaki 5-3-28 Nishikujo, Konohana-ku, Osaka-shi, Japan Inside Hitachi Zosen Corporation (56) References JP-A-59-183981 (JP, A) JP-A-3-114671 (JP, A) JP-A-55-81085 (JP, A) JP-A-6-238447 (JP, A) JP-A-62-38766 (JP, A) JP-A-59-229286 (JP, A) JP, A) JP-A-60-130473 (JP, A) JP-A-60-261675 (JP, A) JP-A-56-45275 (JP, A) JP-A-56-74376 (JP, A) 62-137176 (JP, A) Japanese Utility Model Application Hei 4-75672 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/127 B23K 9/095 B23K 9/12 B23K 10 / 00

Claims (2)

(57) [Claims] 1. A delay control system in which a sensor is placed ahead of a welding robot, and a corrugation shape is previously set to NC.
Corrugated part welding method in a corrugated lap joint welding robot that calculates and welds as data,
A parameter for arbitrarily changing the welding speed and the welding torch angle is added to the NC data of the corrugated part created when the software for controlling the robot is started , and
Where the angle changes, the welding torch reaches that point
Gradually change the torch angle from just before
The heat, and in places where residual heat is concentrated
Reduces the heat input to the welding line by increasing the welding speed.
Control welding speed and welding torch angle
A method for welding a corrugated portion in a welding robot for splicing corrugated lap boards. 2. The method according to claim 1, wherein the mounting direction of the membrane is changed.
In places where welding conditions are different, the molten metal
Welding speed and welding torch angle to prevent dripping
Adjusting and controlling welding speed and welding torch angle
The corrugated lap joint according to claim 1, characterized in that:
Corrugation welding method for welding robot.