JPS6326274A - Automatic fillet welding method - Google Patents

Abstract

PURPOSE:To considerably save manpower by detecting the deviation of the moving route of a torch in accordance with an actual weld line and correcting the torch position in addition to the teaching route control of a main axis system. CONSTITUTION:An X-axis servo unit drives an X-axis driving motor by the command from a main computer 100 and a welding robot starts traveling forward in a welding direction when the welding with a No.1 torch 41A ends. A weaving device 37A starts operating simultaneously and the No.1 torch 41A starts oscillating. The action to correct the torch position by an arc sensing method is then started. Welding current values are taken in by arc sensing units 104A, 104B and the welding currents at the oscillating angles of the torches 41A, 41B are calculated. Subcomputers 100A, 100B command the torch positions to the U-axis servo unit and V-axis servo unit in accordance with the results of such calculations. The torch 41A, 41B are, therefore, subjected to the correction of the positions based on the actual weld line detected in real time with respect to the teaching route.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic welding method suitable for fillet welding of large structures such as road bridges, railway bridges, and pedestrian bridges.

[Conventional technology]

In bridge structures, the main member (■-shaped steel material) is reinforced by attaching horizontal reinforcing members in the longitudinal direction of the main member and vertical reinforcing members perpendicular to the main member in a fixed arrangement pattern. These reinforcing materials are usually fixed to the main material by performing fillet welding on both sides of the edges that contact the main material and by performing square wrap welding on the ends.

By the way, for welding such structures, a dedicated welding robot, for example, a self-propelled portal type welding robot device as described in Japanese Patent Application Laid-Open No. 59-73185, is generally used. Structurally, this device includes a torch,
Cartesian coordinate axis drive system that can be driven in the X-, Y-, and Z-axis directions and a rotation axis (θ-axis) for controlling the torch attitude (orientation)
It has a drive system, and for coordinate control (torch position control),
Detect the deviation width of the torch position from the reference position with respect to the workpiece welding line using a start/end detection device or other detection means, and control the above-mentioned orthogonal coordinate axis drive system and rotation axis drive system so that the deviation width becomes zero. A so-called automatic tracing control system is adopted.

In this automatic tracing control method, it is important to accurately detect the position of the weld line, but it may be practically impossible to directly detect the position of the weld line depending on the shape of the workpiece.
Most of the current methods of detecting weld lines are indirect or relative detection, so there may be errors in cutting the workpiece, and installation (
If there is an error (temporary fixing), collapse, or thermal distortion due to welding, misalignment will occur in the weld, and this will be a significant problem, especially at the beginning and end.

In the above-mentioned bridge structure, it is necessary to apply square wrap welding to the starting and ending parts in order to compensate for its strength, so the current situation is that a great deal of labor and time is required for the modification work.

As another method of controlling the position of the torch, the coordinate information of the torch movement path with respect to the welding line is created in advance as numerical data (NC data), and a numerical control device is used to control the position of the torch.
There is an NC control method for controlling the torch along the torch movement path given by the C data. According to this control method, the above-mentioned problem of welding line detection is eliminated, and the detection means is also unnecessary. However, in this method, the coordinate information of the welding line is fixed information that is input in advance based on the drawing. So,
If the position of the workpiece deviates from the reference coordinates given to the workpiece table (surface plate) of the welding equipment, or if there is a cutting error, installation (temporary fixing) error, or thermal distortion due to tipping or welding, the NC It is not possible to absorb the deviation in the torch movement path caused by the deviation between the teaching welding line given by the data and the actual welding line, and as in the case of the above-mentioned tracing control method,
A large amount of rework is required, and inputting NC data is very troublesome.

This invention was made to solve the above-mentioned conventional problems, and it is possible to accurately perform automatic square wrap welding at the beginning and end, and it is possible to achieve significant labor savings compared to the conventional method. An object of the present invention is to provide an automatic fillet welding method that can reduce welding costs.In order to achieve the above object, the present invention provides the movement path and attitude of the twin torches by a spindle system controlled by a numerical control method. An auxiliary shaft system supported by the main shaft system and independent of the numerical control system is configured to correct the movement paths of one and the other of the twin torches.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

Before explaining the automatic welding method of the present invention, a welding robot device to which the present invention is applied will be explained.

In FIG. 1, reference numeral 1 and IA are guide rails, which are laid on a back-and-forth direction rail laying frame B on a workpiece mounting surface plate A, and extend in parallel at a predetermined interval. , a welding robot runs on the IA. This traveling direction becomes the X-axis direction of the welding robot. The welding robot is oriented perpendicular to guide rail 1 and IA (left and right)
A garter 2 extending horizontally to the garter 2, a garter support 3.3A hanging down while supporting both ends of the garter 2, and a garter support 3.3A extending horizontally to the garter 2.
The robot support mechanism has a gate-shaped robot support mechanism consisting of rectangular saddles 4.4A each of which is erected and whose longitudinal direction is in the same direction as the guide rail 1.
Rail running wheels 5 (fifth
It is mounted on the guide rails 1 and IA via the guide rails 1 and IA so as to be freely movable. In FIG. 5, 6.6A is a wheel support frame attached to the lower surface of the saddle 4, 7 is a drive motor (X-axis drive motor) attached to the outer support frame 6, and 8 is an axis of the X-axis drive motor 7. A rack 9, which is a binion connected to the end and engages with the binion 8, is provided on the pedestal B and extends parallel to the direction of the guide rail 1, and 7 to 9 constitute a welding robot X-axis direction drive mechanism. are doing.

As shown in FIG. 4, the gutter 2 of the robot support mechanism has a guide 10 extending over almost the entire length on its upper and lower surfaces, and an I/O
A, and supports a transverse truck 11 that is guided by the guide 10 and IOA and travels in a direction (Y-axis) perpendicular to the X-axis. As shown in FIG. The transverse truck 11 is provided at the lower end of the leg portion 11b that is close to and parallel to the vertical plane.
A pinion 14 connected to the shaft end of the drive motor 13 is attached to a vertical surface of the garter 2 opposite to the vertical surface and extends in the longitudinal direction of the garter 2. It is engaged with the rack 15. 13 to 15 constitute a welding robot Y-axis drive mechanism. Reference numeral 16 indicates a pair of Y-axis traveling guide rollers.

A holding cylinder member 17 that also serves as a guide for the vertical axis (vertical axis) is attached to the front surface of the leg portion 11b of the transverse truck 11,
The hollow vertical shaft 18 is oriented perpendicularly to the holding cylinder member 17 (X
Axial direction) is slidably inserted. A rail 19 extending vertically is attached to the surface of the vertical shaft 18.
A pair of guide rolls 20 that engage with and are guided by both side surfaces of the rail 19 are provided on the upper and lower sides of the holding cylinder member 17 on a surface that is close to and parallel to the above-mentioned surface. A rack 21 extending vertically is attached to the other surface of the vertical shaft 18, and a rack 21 is connected to the shaft of a drive motor 22 (Z-axis drive motor) supported by the holding cylinder member 17. A pinion 23 is engaged, and 21 to 23 constitute a welding robot Z-axis drive mechanism. An auxiliary shaft system support seat (rotating seat 24) coaxial with the vertical shaft 18 is rotatably connected to the lower part of the vertical shaft 18.
A drive motor 25 is housed and held at the lower end of the vertical shaft 18.
It is driven horizontally by a θ-axis drive mechanism (swing mechanism) consisting of a θ-axis drive motor (θ-axis drive motor) and a speed reducer (not shown). This θ axis is used to control the attitude of the twin torches so that they are perpendicular to the welding direction when the twin torches are moved, which will be described later. The above-mentioned X-axis, Y-axis, Z-axis, and θ-axis are collectively referred to as the main axis system hereinafter.

The rotating seat portion 24 is shown in FIGS. 2, 3 (a) and (b).
As shown in FIG.
Electric horizontal copying slider device 27A for A1 torch
is fixed. The slider (T-axis slider) 28A of this copying slider device 27A moves in the left-right direction (the gutter 2
It is horizontally movable in the same direction as the upper guide IO (the moving direction of this slider axis is hereinafter referred to as the T-axis), and is driven by a drive motor 29A (T-axis drive motor) supported by the device fixing part. At the tip of the T-axis slider 28A, there is a 1-inch mark so as to form a horizontal block shape with the T-axis slider 28A.
An electric vertical copying slider device 1130A for the torch is fixed. A slider (U-axis slider) 31A of this copying slider device 30A is oriented vertically (in the direction of the vertical axis 18) and is driven by a drive motor (U-axis drive motor) 32A attached to the top surface of the device. Hereinafter, the moving direction of the slider 31A will be referred to as the U-axis direction. Slider 31
An electric horizontal copying slider device 33A for the first torch is attached to the lower end of A. This slider device 33
The slider A (■-axis slider) 34A faces in the front-rear direction (the direction of the guide rail 1) and is driven by a drive motor (■-axis drive motor) 35A. The slider 34
The moving direction axis of A is hereinafter referred to as the ■ axis. The T-axis, U-axis, and V-axis mentioned above are hereinafter collectively referred to as the first auxiliary axis system.

A vertical shaft 36A hangs down from the above-mentioned axis slider 34A, and a torch support mechanism 3 is attached to the lower end of the vertical shaft 36A.
7A is provided. This torch support mechanism 37A is a weaving device, and as shown in FIG. It has a drive motor 40a for adjusting the rotation, and a motor 40b for adjusting during rocking.

This swinging shaft member 39A has its lower end supported by a pin 42A at the lower part of the support frame 38A, and a roller 39a provided at the upper part is removably engaged with a horizontal elongated hole 38a formed in the support frame 38A. It is swingably held by the support frame 38A. The lower part of the support frame 38A and the swing shaft member 39
Attached to the upper part of A are gripping frames 43A and 43A that grip the torch 41A, respectively. The torch is held by the swing shaft member 39A in a direction parallel to the extension line of the Z-axis, and is supported with the extension line of the Z-axis being bent toward the corner inner member.

A starting end detection device 44 is provided at the lower end of the swing shaft member 39A.
A is provided. As shown in FIG. 6, this starting end detection device has a cylinder 46a with a photoelectric starting end detector 45a attached to the rod end. A block 47 provided at the lower end of the block 47 and protruding toward the side 1 torch 41A
It is pivotally supported by an underframe 48A fixed to the side of the torch A, so that it can swing back and forth, and is normally urged forward by an elastic device 49a, so that the starting end detector 45A is connected to the floor 1 torch 41A.
It is in a retracted tilted position located a predetermined height above the height,
When the rod is extended, the starting end detector 45a descends to a position almost close to the height of the tip of the floor 1 torch 41A,
It precedes by a predetermined distance Lx.

In addition, since the welding robot of this embodiment is a twin torch type, the above-mentioned electric longitudinal copying slider device, electric vertical copying slider device, electric horizontal copying slider device,
The weaving device is 11kL2) - Another one for Chi 41B.
One for the second floor torch 41B is shown with a suffix B appended to the numerical code, and these constitute a first auxiliary shaft system. N121--The torch 41B is connected to the N111 torch 4 across the extension line of the Z-axis within a plane including the Z-axis.
It faces 1A.

Further, at the lower end of the swing shaft member 39B on the side of the second torch 41B, a terminal end detection device 44b having the same configuration as the start end detection device 44a is provided. The cylinder 44b of this end detector 44b is biased rearward by an elastic device, and when the rod is extended, the end detector 45b moves behind the Nl12 torch 41B by a predetermined distance Lx.

The wires guided to the No. 1 torch 41A and No. 2 torch 41B are the pack wires 51A placed on one saddle 4.
, 51B to bushing side wire feeding devices 52A, 52
B, conduit cables 50A, 50B, pull side wire feeding device 53A, 53B1 conduit cable 50A,
Guided through 50B. On the other saddle 4A, 1
lhl) - welding power source for chi 60A, 1li121-- welding power source for chi 60B, numerical control device (NC control device) 61,
An automatic copy control device 62 is provided. 63 is a guide device for control cables, hoses, etc.

FIG. 7 schematically shows the operations of the above-mentioned main shaft system and auxiliary shaft system.

Next, the control system of the welding robot will be explained with reference to the control block shown in FIG. In the figure, 100 is the main computer of the NC control device, and the NC data D
Read the NC data D from the bubble cassette C that stores the X! An X-axis servo unit that controls the th drive motor 7, a Y-axis servo unit that converts Y-axis related data into a command signal and controls the Y-axis drive motor 13, and a Y-axis servo unit that converts Z-axis related data into a command signal and drives the Z-axis. The Z-axis servo unit that controls the motor 22 converts the θ-axis related data into a command signal and sends it to the θ-axis servo unit that controls the θ-axis drive motor 25, respectively. In addition, the main computer 1
00 is connected to a CRT display 101, an operation panel 102 having a keyboard of the CRT display and other function keys, and a remote pendant 103.

100A and 100B are computers (hereinafter referred to as subcomputers) of automatic copying control devices 62A and 62B for the 1lhl torch and the 2nd torch, respectively. The main control operations by the subcomputer 100A are as follows, and these control operations are executed according to a predetermined sequence.

fl) A U-axis servo unit that commands the wire sensing operation and controls the U-axis drive motors 32A and 32B; ■ A U-axis servo unit that controls the axis drive motors 35A and 35B; and ■ Gives a position correction amount to the axis servo unit, and The positions of the 1st torch and 11h2 torch are controlled to ensure the optimum vertical distance and optimum horizontal distance to the welding line.

(2) Give a detection operation command to the start edge detector 44a, receive the detection signal from the start edge detector 45a, give a reverse command to the T-axis servo unit that controls the T-axis drive motors 29A and 29B, and start square wrap welding at the start edge. To position 1 torch 41A
, 41B.

(3) Command the arc sensing operation, take in the detected value (welding current) sent out by the arc sensing operation parts l-104A and 104B, process this, and drive the U-axis drive motor 3.
2A, 32B and the V-axis servo unit that controls the V-axis drive motors 35A, 35B. Give a position command signal to the U-axis servo unit that controls the V-axis drive motors 35A and 35B. 1A1 2
Control the torch so that it points toward the actual welding line.

(4) Give an operation start command to the end detection device 44b, receive the detection signal from the end detector 45b, give a forward command to the T-axis servo unit that controls the T-axis drive motors 29A and 29B, and start end square wrap welding. To position 1 torch 41A
, 41B.

(51N The main computer 10 sets the welding conditions (welding current, voltage, etc.) based on the leg length data stored in the C data D.
0, the welding power supply rR60 is installed based on the welding conditions.
Controls the output of A and 60B.

Based on the leg length data stored in the f6JNG data D, the weaving conditions (during weaving, number of weavings) are received through the main computer 100, and the drive motors 40a, 40a of the weaving devices 37A, 37B are
A weaving command (start, stop, during weaving, number of times of weaving) is given to the servo unit that controls the weaving width adjustment motors 40b, 40b. Note that LS in FIG. 8 indicates a limit switch for detecting the origin and preventing overrun.

Next, the operation of this device will be explained. As shown in FIG. 9, the case where the first horizontal reinforcement member 211, the second horizontal reinforcement member 212, and the vertical reinforcement member 212 are welded to the main member (I-shaped girder) 200 is explained. explain. For convenience of explanation, the main material 200 is in a standard position on the surface plate A, that is, the horizontal and vertical welding lines WLa, WL
In a posture where b is parallel to the X-axis and Y-axis, respectively, the loading is carried out,
It is assumed that it is installed. Figure 10 shows another shape of the reinforcing material (.

■Preparation step Welding operator sets bubble force) C to NC control device 61
Set to . Once the bubble cassette C is set, welding preparation work is carried out in an interactive manner between the main computer 100 and the welding operator.

The welding operator specifies the workpiece width using the keyboard of the CRT display 101, reads out the shape data of the workpiece width stored in the bubble force set +-C, and presses the CR.
Display the plan view of the workpiece on the T screen. The welding operator turns on the welding start switch on the operation panel 102 after confirming that the workpiece on the surface plate A matches the workpiece imaged on the screen of the CRT display 101 and the actual workpiece. When the welding start switch is turned on,
The main computer 100 reads the NC data D regarding the workpiece and proceeds with the following steps according to the flow shown in FIG. The welding is performed from the left end (coordinate Psa) to the right end (coordinate Pea) in the diagram of the first lateral reinforcement 211 shown in FIG. 9, and then from the left end (coordinate Psb) to the right end in the diagram of the second lateral reinforcement 212. to (coordinates Feb),
Next, in the diagram of the vertical reinforcement 213, the upper @ (coordinates PsC
Welding is performed in the following order from the welding point to the bottom end (Pec). This welding order is specified by writing each of the above coordinates in the bubble cassette C as a user teaching. Further, as user teaching, in addition to the distance between these coordinates (teaching coordinates), the leg length is written.

■Positioning to the welding start end (spindle control) The main computer 100 calculates the starting point coordinates psa (xs, ys, zs) of the teaching welding lines WLa and WLb of the workpiece.
, and read the NC data of the torch direction (angle) θf,
Coordinate X5fd-X-axis servo unit, coordinate) r3 to Y
The torch angle θf is commanded to each of the θ-axis servo units. As a result, the robot support mechanism is driven by the X-axis drive mechanism and runs on the kite rail, the traversing cart 11 runs on the gutter 2 by the Y-axis drive mechanism, and the torch moves to the origin coordinate Po (xo, yo, zo)
Move from to the coordinates (xs, ys, zo). Incidentally, the torch angle θf is the angle when the 11il11 torch 41A and the 1Vh2 torch 41B are lined up in the gutter 2 direction (
Assume that θf=O). Next, the main computer 100
commands the coordinate zO to the X-axis servo unit. As a result, the vertical axis 18 descends and the torch moves to the coordinate Psa (xs
, ys, zs).

■Positioning of the welding start end (auxiliary axis control) (8) Torch position correction by wire sensing When the position control by the main axis to the starting point coordinate Psa by offline teaching is completed, the torch position correction operation by the wire sensing method is started. This wire sensing is
For example, the technique described in Japanese Unexamined Patent Publication No. 54-124850 is applied. That is, in the No. 1 torch 41A, the U-axis slider 31A is lowered to a position where the wire tip contacts the I-shaped girder 200, and then the specified vertical distance Lz
Then, the (1) axis slider 34A moves toward the first horizontal reinforcing member 211, and the tip of the wire moves up toward the first horizontal reinforcing member 211.
After moving to a position where it contacts the reinforcing member 211, it performs an operation of retreating by a prescribed distance Ly. These specified distances Lz and L
y is the optimum vertical distance and optimum horizontal distance that the wire tip should maintain from the welding line. Similar correction control is also executed for the second torch 41B.

(Torch welding start position correction by start edge detection When the position correction by wire sensing is completed, a command to advance the T-axis sliders 28A, 28B is given to the T-axis servo unit, and an operation start command is given to the start end detection device 44a, The shaft sliders 28A and 28B are driven forward by the T-axis drive mechanism, and the rod of the cylinder 44a of the start end detection device 44a is lowered, and the start end detector 45a moves to the front end side of the first lateral reinforcing member 211. The lower edge portion of the reinforcing member 211 is scanned. When the starting edge detector 45a detects the front end of the first horizontal reinforcing member 211, the starting edge detection device 44a receives a retreat command and returns the starting edge detector 45a to the retreating position.T-axis After the front end detection, the slider 28B further detects the start end detector 45a.
The first torch 41A is driven backward by a leading distance Lx+ΔLx. As a result, the fish 1 torch 41A is positioned at a position that is backward from the front end of the horizontal reinforcing member 211 by ΔLx in the X-axis direction. The second torch 41B is similarly controlled.

■Welding work - Square wrap welding at the beginning When the position correction using the auxiliary shaft system described above is completed, the welding power sources 60A and 60B start supplying power to the wire, and square wrap welding is performed on the tip of the first horizontal reinforcing member 211. administered. During this time, the X-axis drive motor 7 is driven, and the N[Lll-- torch 41A and the second torch 41B move backward by a certain distance (ΔLx).

■Welding work - When the fillet welding neck 1 torch 41A moves by the above-mentioned fixed distance and the square wrap welding of the above-mentioned starting end is completed, the X-axis servo unit drives the X-axis drive motor 7 according to a command from the main computer 100, The welding robot starts traveling forward in the welding direction (toward the rear end side of the first reinforcing member 211) on the guide rail. At the same time, the weaving device 37A starts operating, the Kan 1 torch 41A starts swinging, and the torch position correction operation using the arc sensing method starts. For this arc sensing, for example, the technique described in Japanese Patent Application Laid-Open No. 58-53375 is applied. The arc sensing units 104A and 1.04B take in the welding current detection value, calculate the welding current at the left and right swing angle when the first torches 41A and 41B point at the corresponding actual welding line, and calculate the calculation result. Based on this, the sub-computers 100A and 100B instruct the U-axis servo unit and ■-axis servo unit to correct the torch position.

Therefore, the first torch 41A1 and the second torch 41B move at a prescribed speed in the The robot runs while performing fillet welding on both sides of the first horizontal reinforcement member 211 by copy welding.

■Welding work - When the rear end square winding welding torches 41A, 41B move to the vicinity of the rear end of the first horizontal reinforcement member 211, that is, the teaching end point coordinate Pea
When (xe, yes ze) is reached, the terminal detection device 4
4a receives an operation command and extends the rod of cylinder 44b. When the end detector 45b detects the rear end of the first lateral reinforcement 211, the weaving devices 37A and 37B stop operating, and the arc sensing operation is stopped. at the same time,
A deceleration/stop command is given to the X-axis servo unit, a start-up acceleration command is given to the T-axis servo unit, and the X-axis drive motor 7 and T! III! After the U-shift motors 29A and 29B operate together for a certain period of time, the former stops and the latter two move to constant speed drive, and the main body responsible for driving the torches 41A and 41B shifts from the X-axis of the main shaft system to the auxiliary shaft system. Switches to the T-axis. During this driving-main switching section, the above-mentioned joint control is performed to maintain the torches 41A, 41B at a constant speed. After the termination is detected, when the torches 41A and 41B move by a predetermined distance (distance between the torch and the termination detector Lx+ΔLx), the T-axis slider 28A
, 28B are driven backward by a certain distance (ΔLx), and during this time, the square wrap welding of the rear end is completed.

When the above sequence is completed, the first torch 41A and the second torch 41B are controlled to return to the origin coordinates PO, and the above sequences ① to ② are executed for the second horizontal reinforcing member 212. When this sequence for the second reinforcing member 212 is completed, the first torch 41ASN12)-41B moves to the teaching start point Psc of the vertical reinforcing member 213.
At this time, the θ-axis is controlled to rotate by 90 degrees. , In this way, in this embodiment, the spindle system connects the torch to the NC
The torch is controlled to move along the movement path (teaching path) based on the welding line taught by data, and the auxiliary axis system corrects the torch position while detecting deviations in the torch movement path in real time based on the actual welding line. .

Therefore, in this embodiment, the user teaching to write to the bubble cassette can be made extremely simple, and even if the target is a large structure, the burden on the operator is small, and labor savings can be achieved. can.

In this example, the main shaft system controls the teaching start point coordinates, detects the start end using this coordinate P as a base point, specifies the square wrap welding start position, and controls the torch to the teaching end point coordinates at the rear end. Since the end point is detected using these coordinates as a base point and the starting position of square wrap welding is specified, square wrap welding can be performed automatically and accurately.

〔Effect of the invention〕

As explained above, the present invention can automatically and accurately perform square wrap welding at the start and end of the workpiece, which eliminates the need for manual welding work at the start and end of the workpiece. is an off-line teaching method using NC, and the user only needs to input position-related data and welding condition-related data for user teaching, which eliminates the need for troublesome teaching work, making it suitable for large-scale applications. Even for structures, the necessary welding can be performed by a welding operator, and the welding cost can be significantly reduced compared to conventional methods due to the labor-saving effect.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted perspective view showing an embodiment of the present invention, and FIG. 2 is a partially omitted front view showing an auxiliary shaft system in the above embodiment.
FIG. 3(a) is a side view of FIG. 2, FIG. 3(a) is a side view showing the torch support mechanism in the above embodiment, and FIG. 4 is the main shaft (X axis, Y axis) portion in the above embodiment. FIG. 5 is a front view showing the main parts of the main shaft system (X-axis) in the above embodiment, FIG. 6 is a front view of the start end detection device in the above embodiment, and FIG. 7 is a main shaft A diagram showing the operation of the system and the auxiliary shaft system, FIG. 8 is a diagram showing the control block, FIG. 9 is a diagram showing a part of the structure to which the above embodiment is applied, and FIG. 10 is a diagram to which the above embodiment is applied. FIG. 11 is a perspective view showing an example of a reinforcing member, and FIG. 11 is a diagram showing a control flowchart of the above embodiment. 1, IA-guide rail, 11--transverse truck, 18-vertical axis, 24-swivel seat, 28A, 28B...-T-axis slider, 30A, 30 B-=U-axis slider 35 A,
35 BV axis slider, 37A, 37B - Weaving device, 41A, 41B - Torch, 44a -
-Starting end detection device, 44b-Ending end detection device, 60A, 60
B-Welding power source, 61-NC control device, 62--Automatic tracing control device.

Claims (4)

[Claims] (1) A main shaft system controlled by a numerical control system gives the movement path and attitude of the twin torches, and an auxiliary shaft system supported by the main shaft system and independent from the numerical control system controls one and the other of the twin torches. An automatic fillet welding method characterized by correcting the movement path of the fillet. (2) The fillet welding method according to claim 1, wherein in the torch movement path given by the main shaft system, the auxiliary shaft system corrects the torch position by tracing control using an arc sensing method. (3) One side of the longitudinal drive system of the auxiliary shaft system has a retractable starting edge detection device that precedes the torch, and the starting edge detection device detects the starting edge of the workpiece based on the starting point of the movement path given by the main shaft system. 3. The automatic fillet welding method according to claim 1 or 2, wherein the start position of square wrap welding at the starting end is specified, and the auxiliary shaft system controls the torch to the specified position. (4) One side of the longitudinal drive system of the auxiliary shaft system has a retractable end detection device that follows the torch, and the end detection device detects the end of the workpiece using the end point of the movement path provided by the main shaft system as a base point. 3. The automatic fillet welding method according to claim 1, wherein the end square turn welding start position is specified by the auxiliary shaft system, and the torch is controlled to the specified position by the auxiliary shaft system.