JP2000233278A - Welding device and welding method following schedule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically weld a groove line uniformly with uniform bead thickness by deciding a welding condition corresponding to the deviation of a groove shape detected or calculated with an interpolation method from a reference groove shape at a welding condition selection point and the point detecting a groove shape with learning. SOLUTION: By driving a welding mechanisms with an electrical device of a relay box 30, a personal computer 41 gives a welding condition to the electrical device of the relay device 30 in accordance with a welding schedule. The personal computer 41, based on the welding condition table of this time and the teaching data table of this time, corrects the respective welding condition at a welding condition selection point (the position decided by distance data of the welding condition table) in accordance with the deviation quantity of the groove shape by the detected groove shape of the corresponding position on the teaching table for a reference groove shape (a plate thickness, a route width, a groove angle) or the groove shape calculated with an interpolation method, and the corrected welding condition is written on the welding schedule table corresponding to the position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automatic welding in which a groove of a material to be welded is welded in accordance with a welding schedule set in a computer, and in particular, though not intended to be limited to this, an end face. The present invention relates to an apparatus and a welding method for performing multi-layer welding on a groove between two steel pipes that have been butted and continuous by turning a welding torch around the steel pipes by an automatic welding robot.

[0002]

2. Description of the Related Art For a series of welding trajectories in which welding conditions need to be changed during welding, a welding schedule in which welding conditions are determined in advance for each welding condition switching point is created and registered in a memory. At the time of welding, it is preferable to perform automatic welding according to a schedule in the memory, in which welding conditions are sequentially read out from a memory in accordance with the progress of welding and the welding conditions are switched.

When the groove attitude (horizontal, vertical, 45 degrees, xx degrees), which is the direction of the groove with respect to the horizontal plane (or vertical plane), changes on the welding expected locus, the welding conditions are changed accordingly. Must. For example, in the most typical example, in a ring-shaped groove (groove extending in a circumferential direction) between two horizontal steel pipes whose end faces are continuous with each other, a full-width welding, a horizontal welding, and a downward welding are used. Is performed continuously, and a small change in welding conditions is required during girth welding.

Japanese Patent Application Laid-Open No. 62-259,673 discloses that in order to weld a ring-shaped groove between two horizontal steel pipes, the entire circumference is divided into eight equal sections, and each section is opened. Given the preceding dimension data and the bead thickness to be formed in the current pass, the bead width of the current pass and the required amount of weld metal per unit length are calculated based on these, and the calculated value is calculated. Further, the weaving width and the welding speed are calculated based on the specified welding current and the welding current, the welding speed and the weaving width are set as welding conditions for the corresponding section in the welding schedule, and An automatic welding method has been proposed in which welding is performed according to a schedule.

[0005]

In the above-described eight divisions of the entire circumference of the horizontal steel pipe, the posture of the welding torch changes greatly during one section. Control is too coarse. Further, the groove shape is a parameter for the welding conditions, but giving one groove shape in one section is presumed to have a large dissociation from the actual groove shape. Therefore, the fixed large section is removed, the number of sections and section length can be set arbitrarily, and the groove shape is given at a high density (multiple points) in the circumferential direction, and the welding conditions along the groove line can be adjusted. Preferably, the control is fine.

[0006] By the way, on the welding scheduled locus (bevel line),
If the switching point of the welding condition, which mainly corresponds to the change of the groove attitude, and the point where the groove shape is given (the groove shape giving point; for example, the groove shape detection point) are the same, the groove becomes The reliability of the welding conditions adjusted or corrected based on the shape is high. However, there are cases where the welding conditions are different, and in such a case, it is preferable to set welding conditions that properly correspond to the groove shape.

SUMMARY OF THE INVENTION It is a first object of the present invention to automatically weld a groove with uniform quality in a direction in which the groove extends, and to automatically form a groove with a continuously changing posture and reduce a bead thickness. A second object is to perform uniform welding.

[0008]

[Means for Solving the Problems] (1) The reference shape of the groove (the plate thickness, the route width, the groove angle in Table 1) at each of a plurality of locations on the planned welding locus (ring-shaped groove) ) Reference condition setting means (40; FIG. 5) for determining the corresponding welding conditions (Table 1); means (8 to 12, 30) for inputting the groove shape (detection shape) at each of a plurality of points on the welding scheduled trajectory ); When the groove shape (detection shape) of the switching point is input for the switching point between the plurality of points, the reference shape of the switching point (the plate thickness,
The welding conditions (Table 1) are corrected in accordance with the deviation of the groove shape (detection shape) with respect to the groove width and groove angle), the welding schedule is determined corresponding to the position on the planned welding locus, and the switching is performed. If the groove shape of the point is not input, the groove shape of the switching point is calculated by interpolation based on the groove shapes before and after the point, and the calculated groove shape is shifted from the reference shape of the switching point. In response to the above, the welding conditions are corrected and the welding schedule is determined according to the position on the welding expected locus in the welding schedule.
0; FIGS. 6 and 7); and means (8 to 12, 16 to 18, 30) for welding the planned welding locus in accordance with the welding schedule.

To facilitate understanding, reference numerals or corresponding items of the corresponding elements of the embodiment shown in the drawings and described later are added in parentheses for reference. The same applies to the following.

According to this, even when the groove shape is not given to the switching point of the welding condition, the groove shape between the preceding and following groove shapes is given by the interpolation method, and the reliability of this groove shape is improved. And therefore the reliability of the welding schedule is high. Automatic welding of uniform quality is realized. Further, it is possible to increase the number of switching points of welding conditions without increasing the number of groove shape providing points (for example, groove shape detection points).
Even if the switching point of the welding condition and the groove shape providing point are not at the same position, a groove shape that matches the groove shape of the switching point of the welding condition is given, and a highly reliable welding schedule is obtained. be able to. (2) Reference condition setting means (40; FIG. 5) for determining welding conditions corresponding to the reference shape of the groove at each of a plurality of locations on the planned welding locus; Means for inputting (8-12, 30); for each of the plurality of points, the welding conditions at the location corresponding to the point corresponding to the deviation of the groove shape of the point from the reference shape are corrected and the planned welding locus The welding schedule calculating means (40; FIGS. 6 and 7) for determining the welding schedule corresponding to the above point; and means for welding the planned welding locus in accordance with the welding schedule; U welding equipment.

According to this, welding conditions are determined for points where the groove shape is extracted or given, and the welding schedule is
A series of welding conditions for a series of points at which a groove shape is extracted or given is provided, and points at which a groove shape is extracted or given can be set arbitrarily. Even if the number of welding condition switching points is not particularly large, the number of groove shape imparting points (for example, groove shape detection points) can be increased to obtain a fine welding schedule. (3) Reference condition setting means (40; FIG. 5) for determining welding conditions corresponding to the reference shape of the groove at each of a plurality of positions on the planned welding locus; Means for inputting (8 to 12, 30); for each of the plurality of points, the welding condition is corrected by correcting the welding condition of the point corresponding to the deviation of the groove shape of the point from the reference shape. The welding schedule is determined corresponding to the point on the trajectory, and the switching is performed by interpolation based on the groove shape before and after the switching point where the groove shape among the switching points between the plurality of points is not input. Calculating the groove shape of the point, corresponding to the deviation of the calculated groove shape from the reference shape of the switching point,
Welding condition calculating means (40; FIG. 6,
7); and a means (8-12, 16-18, 30) for welding a scheduled welding locus according to the welding schedule.

According to this, the functions and effects (1) and (2) can be simultaneously obtained. (4) The welding conditions corresponding to the standard shape of the groove at each of the plurality of locations on the planned welding locus are determined in the memory (2 in FIG. 5,
11 to 19); A groove shape is detected at each of a plurality of points on the planned welding trajectory, and written into the memory corresponding to the position (5 in FIG. 6);
For each of the plurality of points, the welding conditions at the location corresponding to the point are corrected in accordance with the deviation of the groove shape of the point from the reference shape, and written to the schedule memory corresponding to the point on the welding expected locus. And calculating the groove shape of the switching point by an interpolation method based on the groove shape before and after the switching point where the groove shape among the switching points between the plurality of points is not input, and performing the switching. The welding conditions are corrected in accordance with the calculated deviation of the groove shape from the reference shape of the point, and written in the schedule memory in correspondence with the position on the welding expected locus (FIG. 6,
(FIG. 7): Welding the planned welding locus according to the welding conditions on the schedule memory (9 to 10 in FIG. 4); a welding method according to the schedule on the memory.

According to this, the functions and effects (1) and (2) can be obtained at the same time. (5) The welding mechanism is a ring-shaped laser circling the steel pipe (14).
A rail (10), a welding truck (11) mounted on the rail (10) and moving around the steel pipe (14) along the rail (10), and a welding truck mounted on the welding truck (11). (12), the traveling drive mechanism (2L, RL, ML) mounted on the welding trolley (11), and the traveling drive mechanism
Driving means (4, 3, 1L) for reverse driving.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0015]

FIG. 1 shows the appearance of a mechanism according to an embodiment of the present invention. The right steel pipe 13 and the left steel pipe 14, which are horizontally arranged with their end faces together, are formed with a groove (FIG. 10). The left steel pipe 14 has a ring-shaped laser coaxially with it.
A rail 10 is fixed.
1 is attached. The welding carriage 11 includes a guide roller and a wheel that meshes with the rail, which holds the rail 10 so as to be movable in the circumferential direction and immovable in the horizontal direction x and the radial direction r. The motor is driven forward and backward by a circular drive electric motor My via a speed reducer (not shown). When the base is driven forward and clockwise, the base of the welding carriage 11 is driven clockwise and reversely. Rotates counterclockwise. That is, a circular motion is made along the rail 10. A rotary encoder Ry is coupled to the electric motor My, which generates one electric pulse per movement of the carriage 11 over a predetermined short distance.

An x-movement mechanism is connected to a base for supporting the wheels of the welding cart 11, and an electric motor for x-movement drive is provided.
The mechanism is driven by the motor Mx, and the forward movement of the electric motor Mx causes the x carriage 19 to move leftward with respect to the base of the welding carriage 11 and the right movement by reverse rotation. A rotary encoder Rx is coupled to the electric motor Mx, which generates one pulse of electric pulse for a predetermined short distance movement of the x-movement table 19.

An advancing / retracting mechanism is connected to the x-moving table 19, and the mechanism is driven by an electric motor Mr for driving advancing and retreating. Move in the direction approaching the center and move away from the center by reverse rotation. A rotary encoder Rr is coupled to the electric motor Mr. The rotary encoder Rr generates one electric pulse for a predetermined short distance of movement of the platform 20.

A tilting mechanism is connected to the reciprocating table 20. The tilting mechanism is driven by an electric motor Mθ for tilting, and the torch holder 21 is tilted with respect to a horizontal plane by the forward rotation of the electric motor Mθ. θ decreases and increases due to reverse rotation. A rotary encoder R.theta. Is coupled to the electric motor M.theta., Which generates one electric pulse per rotation of the torch holder 21 at a predetermined small angle.

The welding torch 12 is supported by a torch holder 21 and forms an angle θ with respect to a horizontal plane. The welding torch 12 is supplied with a welding wire from a wire feeding device 18 (FIG. 2).

The welding mechanism shown in FIG. 1 is a part of the welding system shown in FIG. 2, and is driven by an electric device of the junction box 30. A personal computer 41 as a host is connected to the electric device of the junction box 30, and the personal computer 41 gives welding conditions to the electric device of the junction box 30 according to a welding schedule.

FIG. 3 shows an outline of the electric elements of the junction box 30. The above-mentioned x moving mechanism, advance / retreat mechanism and tilt mechanism include:
Start limit switch Lx that determines the range of motion for each
o, Lro, Lθo and terminal limit switch Lx
e, Lre, and Lθe, when the torch 12 is at the position corresponding to the start end of each mechanism, the start limit switch is open, the end limit switch is closed, and the torch 12 is at the position corresponding to the start end and the end end. When the torch 12 is at the position corresponding to the end of each mechanism, the start limit switch is closed and the end limit switch is open when the torch 12 is at the position corresponding to the end of each mechanism.

Rotary encoders Rx, Rr, and Rθ are coupled to the rotation axes of the electric motors Mx, Mr, and Mθ of the x moving mechanism, the forward / backward mechanism, and the tilting mechanism, respectively. One electric pulse is generated for a predetermined small angle rotation of the electric motor. When the torch 12 is driven, a rotary encoder is generated when the controllers 1x, 1r and 1θ including the microprocessor are energizing the electric motors Mx, Mr and Mθ in the forward direction. The electric pulses generated by the rotary encoder are counted up when the reverse rotation is energized, and the electric pulses generated by the rotary encoder are counted down.
When ro and Lθo are open, the count value is cleared (count data indicates 0).

For example, when the controller 1x is powered on, the controller 1x checks whether the start limit switch Lxo is open (the rotational position of the torch 12 is the start position) and closes it ( (Not at the start end position), the motor driver 2x is instructed to energize the motor in the reverse direction, and the motor driver 2x closes the reverse rotation energizing circuit. Since the reverse rotation energizing circuit includes a start limit switch Lxo and is closed, a reverse current flows through the electric motor Mx and the electric motor Mx
Rotates in reverse. By this reverse rotation, the starting end limit switch Lx
When o is opened, the reverse rotation energizing circuit is opened, the reverse current to the electric motor Mx is cut off, and the electric motor Mx stops. On the other hand, the controller 1x is provided with a start limit switch L
When zo is switched from closed to open, the reverse rotation instruction to the motor driver 2x is released, and the x movement position register (one area of the internal RAM of the microprocessor) is cleared. Here, the x-movement position of the torch 12 is at the beginning of the x-movement range, and the data of the x-movement position register indicates 0 (base point).

The operation of the controllers 1r and 1θ is also 1x
The operation of the motor drivers 2r and 2θ is the same as that of the 2x.

In response to an instruction from the CPU 4, the controller 1w supplies a welding power source 16 to which the torch 12 is connected with a signal for designating a welding current / voltage and ON (energization) / OFF (energization stop), and a fluid supply device. A signal for instructing ON (gas supply) / OFF (supply stop) is given to 17, and a signal for instructing supply speed and ON (supply) / OFF (supply stop) is given to the wire feeding device 18. In CPU4,
The controller 1y, via the input / output (I / O) port 3
1x, 1r, 1θ and 1w, and the operation / display board 8 are selectively connected. This connection is specified by the CPU 4 via the system controller 5. The ROM 6 and the RAM 7 are connected to an address bus and a data bus of the CPU 4. The system controller 5 includes a CPU 4
Control signals specified by the ROM 6 and the RAM 7
It is given to the display board 8.

Referring again to FIG. 2 for PC 41
A three-dimensional display 42, a keyboard and a mouse 43 are connected, and the entire computer system is configured as a control panel. The personal computer 41 generates a welding schedule corresponding to an operator input. And a program for driving the welding mechanism in accordance with the welding schedule to perform welding.

FIG. 4 shows the functions realized by the program according to the operation flow of the operator. Control panel 4
When the power is turned on to 0 and the personal computer 41 completes the initialization of the power-on response, the program is started and the welding operation menu is displayed on the display. The main items on this menu are: Welding condition creation / editing (welding condition creation, welding condition editing) Teaching Welding schedule creation (schedule generation, schedule creation)
Edit) welding work. The operator selects "Welding condition creation and editing" in the display menu of the personal computer 41, and generates or edits welding conditions in the submenu "Welding condition creation" or "Welding condition editing". And then select "Teach" and operate the input key of the operation pendant 8 to sequentially determine the welding torch position for the groove and detect the groove shape at each point. And register it for the current welding operation. Then, the user selects "Create welding schedule" to confirm and register the welding schedule, and then selects "Welding work" to cause the personal computer 41 to execute the welding schedule.

FIG. 5 shows an outline of “welding condition creation / editing” 2. When this is selected, the personal computer 41 displays a submenu of "edit and edit welding conditions". The main items of this submenu are "Create welding condition" and "Edit welding condition". When the operator designates "Edit welding condition", the personal computer 41 displays the welding condition table registered so far. Display a list of cables on the display 42 (steps 11, 16, 17). When the operator specifies one welding condition table in the list, it is displayed on the display 42 (step 18). An example is shown in Table 1. In this specification, the term "table" means a storage area in the memory, a group of information therein, or a data table read out from the storage area and displayed on the display 42.

[0029]

[Table 1]

The "plate thickness (32)", "route width (6)" and "groove angle (35)" in Table 1 are reference groove shape data, and the plate thickness is shown in FIG. The value of T (mm), the root width is the value of the width G of the groove bottom (mm) in FIG. 10, and the groove angle is the inclination angle α (°) of the groove oblique side in FIG. Date
No. "15" means that there are 15 data sets (columns of data). In Table 1, No. 1-9
Only the data set of the data No. is shown. By scrolling to the left, the remaining data No. 10 to 15 data appear on the screen sequentially.

0.0 in the column of “distance” in Table 1
Means the starting point of the circumferential position on the steel pipes 3, 14 and is the first point of the steel pipes 13, 14 after the end of the editing 6 of the teaching data described later.
The position of the welding torch 12 with respect to
(Base position of welding torch). Data No. "100" in the column of "distance" of 2 means a position where the welding torch 12 is rotated from the base point 0.0 by a circular arc length of 100 mm in the circumferential direction. Data No. 1 to 15 are steel pipes 13,
No. 14 means that 15 points in the circumferential direction of the whole or a part of the ring-shaped groove are set as the welding condition switching points. The data of 1 indicates that the welding torch has a distance of 0.0 (base point).
Are the welding conditions to be set when Data No.
The data of No. 2 indicates that the welding torch 12 is at the preceding point (Data N).
o. This is a welding condition that is switched at a position that is 100 mm away from 1) (arc length).

The operator is an unnecessary data No. Is deleted and the missing data No. is deleted. Is added, and data No. Is continuously changed, and each welding condition value is changed to a necessary value this time. When the setting (editing) of the desired welding condition is completed, the welding condition is registered in the personal computer 41 as the current welding condition (steps 18, 19, 15).

When the operator specifies "Create welding condition" instead of "Edit welding condition", the personal computer 4
No. 1 is the same as the welding condition table in Table 1, but
When the data value is blank, "Welding condition input screen" is displayed instead of "Welding condition editing screen" in Table 1, and "* Welding condition is input" instead of "* Edit editing condition." Is displayed. "Is displayed on the display 42. The operator first inputs the reference groove shape (plate thickness, route width & groove angle) on the table (step 12). That is, the plate thickness T, route width G and groove angle α (see FIG. 10) of the basic groove shape of the current welding are input.

Then, welding conditions for each set (data No.) are input. The processing of the operator and the personal computer 41 after inputting the required data is the same as in the case of "welding condition editing" described above. After inputting and editing data,
The created table is registered in the personal computer 41 for the current welding (step 15).

When the registration is completed, the personal computer 41 displays an initial menu screen on the display 42. Next, the operator designates "Teach" and operates the welding mechanism operation key and the control input key of the operation pendant 8 to position the welding torch 12 in the circumferential direction sequentially from the base point 0.0. And teaching is performed at a plurality of points. The base point 0,0 here is
It means the starting point of the circumferential position on the steel pipes 13 and 14, and the welding torch 12 for the steel pipes 13 and 14 when the operating voltage of the entire system shown in FIG. 2 is applied and each part is in a normal standby state. Is the base point 0,0 (the base point position of the welding torch). In addition, teaching is the detection and
Registration. That is, the operator operates the welding mechanism operation key of the operation pendant 8 to drive the welding torch 12 to each of a plurality of points, and presses the groove shape measurement instruction key.

Then, the CPU 4 of the junction box 30 sets the welding torque
In a predetermined sequence, the welding torch is driven to detect the groove shape, and the surface position r1, the rear surface position () r2 of the steel pipe 13 and the positions of four points to (FIG. 10) of the groove wall surface. Is measured. Referring to FIG. 10, the welding torch drive for detecting the groove shape is as follows. First, the welding torch 12 is positioned at a position where the tip of the welding wire faces the outer surface of the steel pipe 13 and the center of the steel pipe 13 is positioned. When the welding wire hits the surface of the steel pipe 13, the welding torch 12 is moved in the r direction, the r position r1 of the welding torch 12 at that time is saved, and the welding torch 12 is moved. Driving in the direction y across the groove, the tip of the welding wire separates from the steel pipe 13 and stops at a position substantially at the center of the groove bottom width (G). Is driven, that is, the welding torch 12 is driven until the position shown in FIG. When contacted, it stops there and saves the r-position r2 of the welding torch. Then, T = r1 = r2 is calculated.

Next, a · T (a is a constant, for example, 1/4)
The welding torch 12 is driven in the r direction until the welding wire comes into contact with the steel pipe 13 until the tip of the welding wire hits the groove wall of the steel pipe 13 (FIG. 10). Save x1. Then, this time, it is driven back in the x direction and the x position x2 when the welding wire comes into contact with the steel pipe 14.
(FIG. 10).

Next, the welding torch 12 is driven in the r direction until b · T (b is a constant, for example, 3/4), and the tip of the welding wire hits the groove wall surface of the steel pipe 13 (FIG. 10). The x position x3 when the welding wire comes into contact with the steel pipe 13 is saved until x is reached. Then, this time, it is driven back in the x direction and the x position x4 when the welding wire comes into contact with the steel pipe 14.
(FIG. 10).

Then, the CPU 4 ends the groove shape detection, and when the operator inputs a registration instruction, T and x
1 to x4 are transferred to the personal computer 41 together with the circumferential position data (the y position data of the groove shape detection point). The personal computer 41 has two straight lines defined by x1 to x4 + / +
Calculates the distance G (route width) between points intersecting with the backing plate 15 and the angle α (groove angle) formed by the two straight lines,
G and α are groove shapes (detected groove shapes), and groove shapes (T, G, α) correspond to teaching points (circumferential position y), and are used for teaching data for welding this time. -Write to Bull.

When the operator inputs the end of teaching, the personal computer 41 executes editing 6 of the teaching data. The contents are shown in FIG. Here, the personal computer 41 sorts the data of the teaching data table so that the first point is the last point and the last point is the first point (the order in which the data is read out as welding progresses). Is replaced (step 21). This process is shown in FIGS. 8A and 8B. As a result, the y-position data of the teaching point is rewritten so that the first point becomes the base point 0.0 (step 22). This process is shown in FIG.

Next, each data No. of the welding condition table (Table 1) for the current welding is shown. Is compared with the teaching point y position of the teaching data table in the circumferential direction y position (data in the distance column) to assign each data No. of the welding condition table. At the same position as the y position,
Data on the ching data table (detected groove shape)
Assign If there is no data at the same position on the teaching data table, the data No. The groove shape at the y position is calculated by an interpolation method based on the data (detected groove shape) on the teaching data table before and after the y position, and the data No. . (Steps 25 and 26). Then, the calculated groove shape is written in the corresponding y position of the teaching data table (2).
7, 28). This process is shown in FIG.

As described above, the groove shape of each point actually detected and the groove shape calculated by the interpolation method based on the groove shape are arranged on the teaching data table, and the welding condition table is obtained.
Data (Table 1). The groove shape (detected value, calculated value) addressed to all of the positions indicated by the teaching data
Will be on the bull.

When the editing 6 of the teaching data is completed, the personal computer 41 displays a main menu. The operator operates the sub-menu “Schedule” for creating a welding schedule.
When “generate welding” is specified, the personal computer 41
Condition creation ”7. The contents are shown in FIG. Here, the personal computer 41 uses the welding condition table for the current welding (Table 1) and the teaching data table for the current welding to switch the welding condition (the welding condition table (Table 1)). 1)
Of each data No. The welding conditions for the "distance" data determined by the "distance" data described above are compared with the reference groove shape (plate thickness, route width, groove angle in Table 1) on the teaching data table. And the corrected welding conditions are written in the welding schedule table corresponding to the y position in accordance with the deviation amount of the detected groove shape (or the groove shape calculated by the interpolation method) at the corresponding position.

Further, there is no corresponding position in the welding condition table (Table 1), and the y position belongs to the y position corresponding to each detected groove shape on the teaching data table. Sections on the table (Table 1) (for example, data No.
The welding conditions (for data No. 1 in Table 1) of the section with a distance of 100 mm between No. 1 and No. 2 were changed to the reference groove shape (Table 1).
A correction is made in accordance with the deviation amount of the detected groove shape from the above (1), and the corrected welding conditions are written in a welding schedule table corresponding to the y position of the detected groove shape.

When the above is completed, the welding schedule
Each data N on the welding condition table (Table 1)
o. The welding conditions (detection points) for each y position (welding condition switching point) determined by the distance data and for each y position having a different position from the y position for which the groove shape was detected in the above “Teaching” 5 are detected. The value corrected according to the groove shape) is written corresponding to the y position.

When the operator designates "schedule editing" which is a sub-menu for creating a welding schedule, the personal computer 41 displays a list of welding schedule tables registered in the personal computer 41. Display 4
2 is displayed. When the operator designates one of them, the contents of the table are displayed on the display 42. The operator can change the data and register it in the personal computer 41 as an update registration or a new registration as another schedule.

When the end of the welding schedule creation is input, the personal computer 41 displays the main menu on the display 42.
To be displayed. When the operator specifies "welding work",
The personal computer 41 displays an input screen for “welding work”. The operator can designate the welding schedule table on this screen to instruct the start of welding, and can perform other instructions and data input. When the start of welding is instructed, the personal computer 41 determines the welding condition at the first position on the welding schedule (corresponding to the position of data No. 1 on the welding condition table (Table 1)). The welding is started, and the welding conditions associated with the y position of the welding torch are sequentially read from the welding schedule table as the welding progresses, and welding is performed in accordance therewith.

In the embodiment described above, the welding conditions
All data Nos. On the table (Table 1) For all of the positions (welding condition switching points) and points where the groove shape was detected by teaching, the reference groove shapes (plate thickness, route width,
The welding conditions corrected in accordance with the detected groove shape or the deviation amount of the groove shape calculated by an interpolation method based on the detected groove shape with respect to the groove angle) are determined, and welding is performed based on this. Therefore, even when the groove shape at the switching point of the welding condition (the y position assigned to each data No. in Table 1) is not detected, the groove shape between the groove shapes before and after that is not detected. Given by the interpolation method, the reliability of this groove shape is high and therefore the reliability of the welding schedule is high. Automatic welding of uniform quality is realized. Further, it is possible to increase the number of switching points of welding conditions without particularly increasing the number of groove shape detection points (teaching points), and to ensure that the switching points of welding conditions and the groove shape detection points are at the same position. If not, a groove shape that matches the groove shape at the switching point of the welding conditions is provided, and a highly reliable welding schedule can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external appearance of a mechanism according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a system configuration according to an embodiment of the present invention.

FIG. 3 is a block diagram showing an electric circuit configuration in the junction box 30 shown in FIG.

FIG. 4 is a flowchart showing an outline of generation of a welding schedule realized by the personal computer 41 shown in FIG. 2 in response to an operator's instruction and a welding operation based on the schedule.

FIG. 5 is a flowchart showing the contents of “welding condition creation / editing” 2 shown in FIG. 4;

FIG. 6 is a flowchart showing the contents of “edit teaching data” 6 shown in FIG. 4;

FIG. 7 is a flowchart showing the contents of "creation of welding locus / condition" 7 shown in FIG.

FIG. 8 is a table showing a process of changing the arrangement of teaching data in “editing teaching data” 6 shown in FIG. 7;

9 is a chart showing a process of interpolating a groove shape to a position where a detected groove shape is missing in “edit teaching data” 6 shown in FIG. 7;

10 is an enlarged vertical section of a part of the steel pipes 13 and 14 to be welded shown in FIG. 1, showing a cross section of a groove and a teaching position of a wire tip.

[Explanation of symbols]

10: Rail 11: Welding trolley 12: Welding torch 13, 14: Steel pipe 19: Elevating base 20: Advance / retreat base 21: Tail holder My, Mx, Mr, Mθ: Electric motor Ry, Rx , Rr, Rθ: Rotary encoder

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshitaka Kawakami 7-6-1, Higashi Narashino, Narashino City, Chiba Prefecture F-term in the Equipment Division, Nippon Steel Welding Industry Co., Ltd. 4E081 AA12 BA19 BA27 CA07 DA01 DA23 DA26 DA48 DA56 DA64 DA79 EA56

Claims (4)

[Claims] 1. A reference condition setting means for determining welding conditions corresponding to a reference shape of a groove at each of a plurality of points on a planned welding locus; means for inputting a groove shape at each of a plurality of points on a planned welding locus; When the groove shape of the switching point is input for the switching point between the plurality of points, the welding condition is corrected according to the deviation of the groove shape from the reference shape of the switching point with respect to the reference shape. If the welding schedule is determined according to the position on the trajectory and the groove shape of the switching point is not input, the groove shape of the switching point is calculated by interpolation based on the groove shapes before and after the switching point. Welding condition calculation means for correcting the welding conditions in accordance with the calculated deviation of the groove shape from the reference shape of the switching point to determine a welding schedule corresponding to a position on a planned welding locus; Welding schedule Means for welding a scheduled welding locus according to the following schedule: a welding apparatus according to the schedule. 2. A reference condition setting means for determining welding conditions corresponding to a reference shape of a groove at each of a plurality of locations on a planned welding locus; means for inputting a groove shape at each of a plurality of points on a planned welding locus; For each of the plurality of points, the welding conditions at the point corresponding to the point corresponding to the deviation of the groove shape of the point from the reference shape are corrected to form a welding schedule corresponding to the point on the planned welding locus. A welding apparatus according to a schedule, comprising: means for calculating welding conditions to be determined; and means for welding a planned welding locus according to the welding schedule. 3. A reference condition setting means for determining welding conditions corresponding to a reference shape of a groove at each of a plurality of locations on a planned welding locus; means for inputting a groove shape at each of a plurality of points on a planned welding locus; For each of the plurality of points, the welding conditions at the point corresponding to the point corresponding to the deviation of the groove shape of the point from the reference shape are corrected, and the welding schedule corresponding to the point on the welding expected locus is corrected. The groove shape of the switching point is calculated by an interpolation method based on the groove shape before and after the switching point where the groove shape among the switching points between the plurality of points is not input. Welding condition calculation means for correcting the welding condition in accordance with the calculated deviation of the groove shape from the reference shape of the point and determining the welding schedule in accordance with the position on the welding expected locus; and the welding schedule -Follow the rules Means for welding a planned welding locus. 4. A welding condition corresponding to a reference shape of a groove at each of a plurality of positions on a welding expected locus is determined in a memory.
A groove shape is detected at each of a plurality of points on the planned welding locus and written in a memory in a position correspondence manner; for each of the plurality of points, the point corresponds to a deviation of the groove shape from the reference shape of the point. The welding conditions of the spots are corrected and written in the schedule memory corresponding to the points on the planned welding locus, and before and after the switching point where the groove shape among the switching points between the plurality of points is not input. The groove shape of the switching point is calculated by interpolation based on the groove shape of the above, and the welding condition is corrected in accordance with the deviation of the calculated groove shape with respect to the reference shape of the switching point to correct the welding target locus. Writing to the schedule memory in accordance with the position of the above; welding the planned welding locus according to the welding conditions on the schedule memory; a welding method according to the schedule on the memory.