JPH0839251A - Corrugated part welding method in welding robot for corrugated lap plate joining - Google Patents

Abstract

PURPOSE:To obtain good weld beads by adding parameters to arbitrarily change a welding speed and welding torch angle to the corrugation shape to be previously inputted as an NC parameter and controlling both at the time of welding by a delayed control system to precede a sensor to a welding robot. CONSTITUTION:The torch angle is gradually changed within a range of the determined Mx. angle from just before the welding torch arrives at the round parts in the skirt parts 20, 21 of corrugations where the angle of the weld zone changes sharply, by which the change in the torch angle in the round parts is smoothed. The welding speed is increased to lower the heat input to a weld line in the round parts of the skirt parts 20, 21 of the corrugations where the radius of curvature is small and the diffusion of heat with respect to the weld length is smaller than in the plane parts and the round parts of the peak parts 22 of the corrugation shape where the concentration of the heat is liable to arise as the welding torch moves while facing the same point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method in a welding robot for joining corrugated lap plates, which welds corrugated membranes together, and more particularly to a method for welding corrugated portions.

[0002]

2. Description of the Related Art Conventionally, a contact type sensor for shape recognition has been used for welding corrugated membranes, and a torch angle control of a welding torch has adopted a copy control method. When a plasma arc welding method, which is a welding method that is faster than the conventionally used TIG welding method, is applied to the welding of the membranes, when a welding torch or the like is operated by the copy control method in the corrugated portion,
The change of the torch angle could not follow the sensing of the contact type sensor, and the welding defect was likely to occur. Therefore, a delay control method has been previously proposed in which a sensor precedes the welding torch so that the welding torch can easily follow the welding torch.

Next, a welding robot adapted to a high-speed plasma arc welding method by using a delay control system preceded by this sensor will be described. 4 is a schematic perspective view thereof, and FIG. 5 is a schematic plan view thereof.

In FIGS. 4 and 5, reference numerals 1 and 2 denote membranes having a corrugation shape, and corrugation shape portions 1B and 2B are formed on the flat portions 1A and 2A at predetermined intervals. The membranes 1 and 2 are fitted with the corrugation-shaped portions 1B and 2B in the vertical direction and the edges are overlapped with each other, so that the corrugated lap joint is long in the direction orthogonal to the direction of the corrugation-shaped portions 1B and 2B. The part 3 is formed. The weld edge 4 is formed at the edge position of the upper membrane 2 in the corrugated laminated plate joint portion 3. A guide rail 10 adjusted in the direction along the welding line 4 is arranged above the welding line 4, and is supported and guided by the guide rail 10 to move in the L direction along the welding line 4. A body 11 is provided.

This welding machine main body 11 has a welding torch 12
However, the horizontal direction W and the vertical direction H orthogonal to the welding line 4
It is provided so as to be freely movable and to be swingable in an arc direction Θ about a horizontal shaft 16 parallel to the left-right direction W at the arc tip of the torch tip. Welding torch 1 here
2 uses a plasma arc welding method. Further, the welding machine main body 11 is provided with a control device 13 for controlling the movement of the welding torch 12 in the left-right direction W, the up-down direction H, and the swing in the arc direction Θ, and the control device 13 includes a delay circuit. It is configured. Further, the welding machine main body 11 has a visual sensor 14 for measuring seam tracking of the welding line at a position ahead of the welding torch 12 in the torch movement direction, and a laser displacement sensor for measuring corrugation shape at a lateral position of the visual sensor 14. 15 are provided.

The welding operation of the corrugated laminated plate joint in the welding robot having the above structure will be described. Adjust the guide rails 10 and, as shown in FIG. 5, welder body 1
The welding torch 12 and the visual sensor 14 provided in No. 1 are set to be 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. Then, by moving the welding machine body 11 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 measurement by 4, 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 lead and the welding torch 12 follows, but the delay amount is delayed by the delay circuit incorporated in the control device 13 so that the welding torch 12 moves in the left-right direction W and the vertical direction H and the horizontal axis. The swing in the arc direction Θ around 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 portion 2A, and when facing the rising slope surface area B of the corrugation-shaped portion 2B, the inclination is tilted. Due to the existence of the angle, the laser displacement sensor 15 cannot promote the reflected light, and the measurement becomes impossible. Then, when the laser displacement sensor 15 faces the top range C, the planar shape of the top returns to a state in which reflected light can be promoted and measurement becomes possible. Similarly, when it faces the falling slope surface range D, the measurement becomes impossible again, and when it faces the rear plane area a of the flat plate 2A, measurement becomes possible. In such a measurement state by the laser displacement sensor 15, the highest point measured in the top range C is the point indicating the center position of the corrugated shape portion 2B. Here, the shape of the corrugation shape portion 2B is given to the control device 13 in advance, and the software for robot control is based on the shape of the corrugation shape portion 2B with the position of the input highest point as a reference point. By creating NC data of the welding line 4 of the corrugated part created when activating, and operating the welding torch 12 with the NC data after a predetermined delay time, speed control and vertical direction in the corrugation shape part 2B. It is possible to control the movement to H and to control the swing in the arc direction Θ about the horizontal axis 16, that is, the torch angle θ.
You can control the changes.

Further, as shown in FIG. 7, the visual sensor 14 performs normal seam tracking for the front welding line range E of the welding line 4 with respect to the flat surface portions 1A and 2A, and the corrugation shape portion welding line range F. When it faces, the detection level rises and it goes out of the visual field of the visual sensor 14, and the measurement becomes impossible. This non-measurable state is the entire area facing the corrugation-shaped portion welding line range F, and the measurement can be performed again when the visual sensor 14 faces the rear welding line range e. As described above, measurement cannot be performed over the entire corrugation-shaped portion welding line range F, but between the corrugation-shaped portion welding line range F and the welding line ranges E and e in the vicinity thereof, the edge portion of the membrane 2 is almost the same. Since it is located in the vertical plane, the corrugation shape portion welding line range is located above the line connecting the coordinates of the starting point measured in the rising slope surface range B and the coordinates of the ending point measured in the falling slope surface range 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 structure, the delay control method in which the sensor precedes is used, and the method of calculating the corrugation shape as NC data in advance is used. Also allows the welding torch to sufficiently follow the welding line. Next, the operation of the corrugated portion of the welding torch 12 will be described in more detail.

As shown in FIG. 8, the corrugated shape has an R1 portion forming a top portion, an R2 portion forming a slope portion,
R that forms the rising and falling skirts
Three parts, a distance L from the center of the apex to the start point of the rising skirt and the end point of the falling skirt, the height h of the apex, and the membrane thickness g are prepared respectively, and the center point of three consecutive R parts and It is obtained by calculating those connecting points. The plurality of types of corrugation shapes obtained in this way are recorded in the memory of the control device. Select one of the corrugation shapes from the highest point of the corrugation shape detected by the sensing of the laser displacement sensor, and based on this shape, select the corrugation shape of the corrugation part that is created when the software for robot control is started. N
C data is created.

Next, a method of calculating NC data performed from the shape of the selected corrugated portion will be described. First, as shown in FIG. 9A, Y-axis data for X-axis data is calculated for each X-axis unit width as an arc on a plane coordinate. Then, the calculated values of the X-axis and the Y-axis are corrected according to a specific speed (movement amount per unit time) to create equidistant data on a plane, as shown in FIG. 9B. To do. Where ○ is the data obtained in the first calculation, △
The marks indicate data obtained by correcting at a specific constant speed, and are evenly spaced on the plane. Next, in the corrected data, each torch angle θ is calculated as shown in FIG. This corrected data (x ₁ y ₁ ) to (x ₃ y
₃ ) and the torch angles θ ₁ and θ ₂ based on N of the corrugated part created when the software of the robot control angle is started.
C data is created. Then, the welding torch height is controlled to follow this, and the welding speed and 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 shape of the corrugated portion given in advance as described above. , Weld defects were found in the following places. (1) A place where the angle of the welded part suddenly changes (2) A place where heat remains due to welding and is thought to adversely affect the weld bead (3) When the installation direction of the membrane changes, Part where welding conditions are different For example, as the part (1) where the angle of the welded part suddenly changes, as shown in FIG. 10, a corrugation-shaped rising skirt 20 and a falling skirt where the angle of the welded part rapidly changes. There is an R portion of the portion 21, and since the torch angle is rapidly changed at this portion, the torch angular velocity is increased and a welding defect is generated. As shown in FIG. 10, as the place where the residual heat of (2) is likely to be concentrated, as shown in FIG. 10, the radius of curvature is small and the place where heat is dissipated with respect to the welding length is smaller than the flat portion. There are R portions of the skirt portion 20 and the falling skirt portion 21,
Further, since the welding torch moves while facing the same point, there is an R portion of the cork-shaped top portion 22 in which heat is considered to be concentrated, and an arrow welding defect is likely to occur.

Regarding the orientation of the membrane, as shown in FIG. 11, there is a bottom membrane 23, a ceiling membrane 24, and a side membrane 25, and the torch is different from the bottom membrane 23 in the portion (3) where welding conditions are different. Downward 26, the torch is upward 27 with respect to the ceiling membrane 24, and the torch is lateral 28 in which the torch moves vertically and horizontally in the horizontal direction, or a cube that vertically and vertically moves in the vertical direction. There is a direction 29, for example, in the vertical direction 29, at the top of the corrugation shape, the molten metal hangs down due to its own weight, causing a welding defect.

The present invention solves the above-mentioned problems. In welding corrugated membranes, when welding corrugated portions, the welding speed and welding torch angle are appropriately controlled to obtain good welding beads. An object of the present invention is to provide a corrugated portion welding method in a welding robot for joining corrugated laminated plates.

[0015]

In order to solve the above-mentioned problems, the welding method for corrugated parts in the welding robot for corrugated lap plate joining of the present invention adopts a delay control system in which a sensor precedes the welding robot, and the corrugation shape is adopted. When calculating and welding as NC data in advance, the parameters for changing the welding speed and welding torch angle are added to the NC data of the corrugated part created when the software for robot control is started. The welding speed and welding torch angle of the portion are controlled to obtain a good welding bead.

[0016]

With the above structure, for example, in the R portion of the corrugation-shaped skirt where the angle of the welded portion changes rapidly,
Before the welding torch reaches the R part, the torch angle is gradually changed within the range of the specified maximum angular velocity so that the torch angle in the R part can be smoothly changed, and the radius of curvature is small. In the R portion of the corrugation-shaped skirt, which radiates less heat than the welding length compared to the flat portion, and in the R portion of the corrugation-shaped top, where the welding torch moves while facing the same point, heat concentration tends to occur. , The welding speed is increased to reduce the heat input to the welding line, and the molten metal on the corrugated welding line has different weights due to the change in the mounting direction of the membrane. By adjusting the welding speed and welding torch angle in order to prevent downward dripping, the corrugated part during welding can be adjusted. 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]

EXAMPLE An example of the present invention will be described below. FIG. 1 is a flow chart for explaining a corrugated portion welding method in a welding robot for corrugated lap plate splicing according to an embodiment of the present invention, the main part of which is a corrugated portion created when the robot control software is activated. In the NC data of No. 2, the parameters for the following items are added to change the welding speed and the welding torch angle. (1) A place where the angle of the welded part changes abruptly (2) A place where heat remains due to welding, which may adversely affect the weld bead (3) By changing the mounting direction of the membrane, Where welding conditions are different Here, the parameters are coefficients and constants for arbitrarily changing the welding speed and the welding torch angle when welding the R portion of the corrugated portion where defects easily occur.

FIG. 2 is a diagram for explaining the control at a location where the angle of the welded portion changes abruptly or where heat remains due to welding. In FIG. 2, in the R portion of the corrugation-shaped rising skirt portion 20, the torch angle is gradually changed from before the welding torch reaches the R portion, whereby the torch angle in the R portion of the rising skirt portion 20 rapidly increases. We try to avoid such changes and make smooth changes. The angle change at this time is set so as to be performed within the range of the determined maximum angle. Further, since the radius R of the rising skirt 20 has a small radius of curvature and the portion where heat is dissipated with respect to the welding length is smaller than the flat portion, the welding speed at this portion is made faster to the welding line. The heat input is reduced. This also applies to the R portion of the corrugation-shaped falling skirt portion 21. Furthermore, in the R portion of the corrugated top portion 22,
Since the welding torch moves toward the same point and is a portion where heat is concentrated, at this portion, at least the welding speed is increased to reduce the heat input to the welding line.
These are performed by adding parameters to the NC data of the corrugated part 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 velocity, and the maximum value is set for the torch angular velocity, but the welding speed and the torch angle are set, for example, by repeating experiments and experience. This makes it possible to appropriately control the welding speed and the welding torch angle during welding, and it is possible to prevent the welding defects caused by the movement of the conventional welding torch.

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

[0020]

As described above, according to the present invention, the delay control system in which the welding robot is preceded by the sensor is adopted, and when the corrugation shape is calculated in advance as NC data and the welding is performed, the angle of the welded portion is sharply increased. Welding speed and welding torch angle at changing locations, locations where welding heat may remain and adversely affect the weld bead, or locations where welding conditions differ due to changes in the orientation of the membrane. By adding the parameter for changing the value arbitrarily to the NC data of the corrugated part created when the robot control software is started, and by appropriately controlling the welding speed and welding torch angle in the corrugated part during welding. , Good welding bead can be obtained, the welding caused by the movement of conventional welding torch Recessed can prevent.

[Brief description of drawings]

FIG. 1 is a flow chart of a main part of a corrugated part welding method in a welding robot for joining corrugated laminated plates according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining control in a portion where the angle of the welded portion changes abruptly or where heat remains due to welding in the corrugated portion welding method.

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

FIG. 4 is a schematic perspective view of a welding robot for joining corrugated laminated boards.

FIG. 5 is a schematic plan view of the welding robot for joining corrugated laminated plates.

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 diagram showing a shape of a corrugated shape portion and dimensions of a main portion thereof.

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

FIG. 10 is a diagram illustrating a portion where the angle of the welded portion changes abruptly and a portion where heat remains due to welding.

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

[Explanation of symbols]

 1, 2 Membrane 3 Corrugated lap plate part 4 Welding line 11 Welding line body 12 Welding torch 13 Control part 14 Visual sensor 15 Laser displacement sensor 20 Rising skirt part 21 Falling skirt part 22 Top part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Miyazaki 5-3-2 Nishikujo 5-chome, Konohana-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Co., Ltd.

Claims (1)

[Claims] 1. A delay control system in which a welding robot is preceded by a sensor is adopted, and a corrugation shape is set to N in advance.
A welding method for a corrugated part in a welding robot for corrugated lap joints, which calculates and welds as C data, in which the welding speed and welding torch angle are included in the NC data of the corrugated part created when the software for controlling the robot is started. A method for welding a corrugated part in a welding robot for joining corrugated lap plates, characterized in that a welding speed and a torch angle of the corrugated part are controlled by adding a parameter for arbitrarily changing the value.