JPS5817706B2 - Long-tailed grass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for vertically welding or circumferentially welding large and heavy objects according to contents stored in a storage device or preset at a set position prior to welding.

Generally, even if the joining line of the workpiece to be welded is straight, if the workpiece is long and a beveling process is being performed, the center line of the beveling process should be finished in a straight line. That is difficult.

In addition, when the welding equipment moves on a fixed rail and the object to be welded is large and heavy, the center line under the groove υn must be aligned exactly with or parallel to the direction of movement of the welding equipment. It is also difficult to place large and heavy objects in the area.

Furthermore, when welding the circumference of the object to be welded, weld the groove υn or position the object so that the center line of the groove and the locus of the tip of the welding torch are always aligned or parallel. It is also difficult to do so.

Therefore, conventional methods have been adopted in which a detection mechanism is installed at the tip of the welding torch so that it follows the groove of the workpiece during welding, but the detection mechanism often malfunctions.

Furthermore, since multi-layer welding is often used in the case of large and heavy objects, it is difficult to cause the welding torch to accurately follow the groove after the weld bead has been placed, especially near the final layer.

Furthermore, when welding large and heavy objects vertically or circumferentially,
Normally, multi-layer welding is performed, and after completing welding of the first layer, the position of the welding torch for the second layer is visually detected and manually set. Since the workpiece to be welded is at a high temperature, it is difficult for the operator to visually detect and manually set the position of the welding torch, which has the drawback of requiring a long setting time.

Further, even when preheating is performed before welding starts, the operator must approach the hot workpiece and set the welding torch position in a short time before the temperature drops below the appropriate preheating temperature.

Furthermore, when welding the second and subsequent layers, in order to reduce welding distortion, it is necessary to start welding the next layer before the humidity of the object to be welded falls below a certain level. It was difficult to set the position of the welding torch in a short time while approaching an object.

The present invention can be applied to vertical joints or circles of workpieces made of large and heavy objects that are difficult to set so that the locus of the tip of the welding torch and the center line of the beveling process are accurately aligned or parallel. In the method of circumferential welding, the center line of the beveling process is divided into a plurality of parts prior to the start of welding of the workpiece, and the position of the tip of the welding torch and the center line of the beveling process are approximately constant at each dividing point. After correcting the position of the welding torch for each division point so that the positional relationship is as shown in FIG. Welding is performed without correcting the position of the welding torch between the dividing points, and at each dividing point, the position of the welding torch is automatically corrected to the memorized or set position. We have proposed a method in which welding is restarted toward the point, and welding is performed between each dividing point without adjusting the position of the welding torch.

Furthermore, when performing multi-layer welding, the present invention presets each position of the welding torch at the welding start position of each layer to a set position before starting welding of the first layer of the workpiece, and groove processing. Divide the center line into multiple parts, and correct the position of the welding torch at each dividing point so that the locus of the tip of the welding torch and the center line of the beveling have a substantially constant positional relationship at each dividing point. After storing the position in the memory device or presetting and saving the set position, welding of the first layer is started, and the welding torch position is not corrected between the welding start position and the next dividing point. Welding is performed, and at each split point, the welding torch position is automatically corrected to the memorized or preset position.Welding is restarted toward the new split point, and the welding torch is moved between each split point. Finish welding the first layer by welding without correcting the position, and then weld the first layer after the second layer.
Welding starts after the welding torch is automatically moved to the preset welding start position before starting welding of the first layer, and similarly to the first layer, the welding torch is moved to the memorized or preset position at each dividing point. We have proposed a method in which welding is continued toward the splitting point after the position of the welding torch has been corrected, and each layer is welded between each splitting point without correcting the position of the welding torch.

The present invention will be explained below with reference to the drawings.

Fig. 1 is an explanatory diagram when the parts to be welded 1, 1 are elongated, such as a cylindrical pressure vessel, and vertical joint welding is performed with a groove 7J []. The plan view is a sectional view seen from the side, and the direction of the joining line is the Y axis, the tangential direction of the circumference of the container is the Z axis, and the radial direction of the container is the Z axis.

As shown in Figure a, if the joining line is a straight line a, but the center line of the beveling is a curved line slightly deviated from the straight line, the center line of the beveling should be adjusted before welding. length l
Divide the welding start position (X1o, Zlo) into a storage device or preset it in a setting device with the welding start position (X1o, Zlo) as the origin,
After that, move the welding torch or detection mechanism C (hereinafter referred to as welding torch) in the Y-axis direction by a length l along the joining line and stop, and move the welding torch to a position suitable for the beveling line up to the next dividing point. Move the welding torch in the X-axis direction so that
=X4. - Store X1o in the storage device or preset it in the setting device.

In this case, when the workpiece to be welded is curved as shown in the cross-sectional views of FIGS. 1 and 1C, the welding torch 2 is also corrected in the radial direction of the cylindrical pressure vessel, that is, in the Z-axis direction.

In the figure, 2 is a welding torch, 2a is the tip of the welding torch, and 3 is a welding wire.

As mentioned above, the tip 2a of the welding torch has moved by l in the Y-axis direction and stopped, so it is also moved in the Z-axis direction to obtain the position of this welding torch Z11=Z1o+z1 or the corrected value Zl"Zll zio to store or preset.

After that, the welding torch is further moved in the Y-axis direction by a length l, then stopped, and moved in the X-axis direction so that it is at a position suitable for the welding torch and the beveling line up to the next dividing point, as described above. , and the position of this welding torch is X1□=X1
゜+x2 or the modified value x2=X1□-X1o is stored or preset.

If there is no need to move the welding torch in two axes at this position, use Zl.

2 Z1□=z1o+Z1 or z2-21=Z1. −Z
lo is memorized or preset, and the positions in the X-axis direction and Z-axis direction (X3, Z3) (X4.
Z4)...--or (X3 y z3) (X4
y z4)... memorize or preset.

After the welding torch is moved to the expected welding end position by repeating the movement and stopping of the welding torch and the storage or presetting of the corrected values in this way, the welding torch is again stored in the welding start position, that is, stored in the storage device or preset at the set position. Return to the origin position (X1o, Zlo).

Next, when welding is started, the welding torch moves by a length l along the Y-axis direction while generating an arc, and the welding torch moves to the position previously stored or preset at this position.
1:X10+x1, Z11=Z10+21,
In this state, welding is continued for a length l along the Y axis.

And at this position, X 12 ” Xl 0 + x
2, the position is corrected to Zl2-Zl=ZIO+z1.

The position of the welding torch is not corrected between each dividing point.

Therefore, the trajectory of the welding torch at the dividing position is a trajectory along the rail on which the welding device is mounted.

Thereafter, in the same manner, welding is completed while the position of the welding torch is corrected step by step so that the position of the welding torch is stored in the storage device or preset in the setting device for each dividing point until the welding end position.

In the above embodiment, the positions to be corrected of the welding torch were set at predetermined equal intervals, and the welding torch was stopped at each position to memorize or preset the position. While moving, if the welding torch deviates from the joining line beyond the allowable range, correct the position of the welding torch and adjust the position in the X-axis direction and Y-axis direction (X
ll-Y,)(Xl.

, ¥2) (X13.¥3)..., and then welding can be performed while correcting the position of the welding torch according to the stored values.

Figure 3 shows a case where the welding equipment moves on a fixed rail, the part to be welded is a large and heavy object, and it is difficult to set the joining line a parallel to the traveling direction γ of the welding equipment. An example is shown.

Even in such a case, for every length l in the Y-axis direction,
Axial positions X1o, X11. X1□, X, 3...
After storing the values, welding can be performed while correcting the position of the welding torch according to the memorized or preset values.

In Figures 1 to 3, for example, by moving the welding torch in the Y-axis direction and generating pulses proportional to the rotation speed of the electric motor, and counting the number of pulses, the position of each dividing point in the Y-axis direction can be determined. If this is determined, the moving speed of the welding torch in the step of memorizing or presetting before the start of welding and the speed during welding can be arbitrarily selected.

In addition, in FIGS. 1 to 3, a vertical seam welding method was explained in which the workpiece is fixed and the welding torch is moved parallel to the center line of the substantially straight groove. The welding method according to the present invention can also be applied to circumferential welding in which the workpiece is rotated by a turning roller and the welding torch is fixed for welding by dividing the center line 1 of the circumferential beveling process.

Also, when you want to change conditions such as welding current, arc voltage, welding speed, etc. at the welding start position, the wide root gap position of the groove, the welding end position, etc. at each dividing point,
By storing or presetting the welding torch position and simultaneously storing or presetting the welding conditions, it is possible to change the welding conditions in the same way as changing the position.

Next, a case where the present invention is applied to multilayer welding will be explained.

The present invention presets each position of the welding torch at the welding start position of each layer to a set position prior to welding,
And as mentioned above, divide the center line of the beveling into multiple parts,
Correcting the position of the welding torch at each dividing point so that the position of the tip of the welding torch and the center line of the beveling have a substantially constant positional relationship at each dividing point, and storing the position in a storage device; Or, after presetting in the setting device, start welding the first layer, and perform welding without correcting the position of the welding torch between the welding start position and the next dividing point,
At each dividing point, the position of the welding torch is automatically corrected to the previously saved position, and welding continues toward the subsequent dividing point, and between each dividing point, welding is performed without adjusting the position of the welding torch. to finish welding the first layer, and then for welding the second and subsequent layers, first preset it in the setting device, move the welding torch so that it is at the welding start position of each layer, and then start welding the second layer. This is a multilayer arc welding method in which each subsequent layer is welded in the same manner as the first layer.

In FIG. 4, 1 and 1 are the objects to be welded, points A to 2 are the positions of the tip 2a of the welding torch when welding each layer, and curves a to l are curves showing the surfaces of the weld beads of each layer.

Prior to welding, the coordinates (X1o, Zlo) of position A of the tip 2a of the welding torch for the first layer are preset in the setting device, and then the coordinates of position @B of the tip 2a of the welding torch for the second layer are preset. Preset (X201 Z20) and do the same below (X3o, Z3o), (X4o.

Z4o),...(X,.

, Z9o). Next, start welding with the tip 2a of the welding torch from the point A (X10 + Zoo) mentioned above, and as mentioned above, adjust the position of the welding torch at each dividing point and weld the first layer. Finish welding.

When the welding of the first layer is completed, the welding torch is moved in the Y-axis direction and returned to the welding start position of the first layer, and then the tip of the welding torch is moved to point B (X
2°Z20) automatically.

In this case, after finishing welding the first layer and before returning the welding torch to the welding start position, move the tip of the welding torch in the X-axis direction and Z-axis direction to set it at point B, and then turn the welding torch back on. It may be moved in the Y-axis direction and returned to the welding start position.

In this way, at the start of welding the second layer, the tip of the welding torch is moved to the position (X20 + Z20) preset in the setting device, and then welding of the second layer is started.

Thereafter, each layer is welded in the same way, with the positions of the welding torch tip set on the setting device (X3o, Z3o), (X40,
Z40),...(X9o.

Zll! Start from O) and complete multilayer welding.

In the welding method of the present invention, the copying mechanism disposed at the tip of the welding torch only needs to be used before welding starts, so the copying mechanism is used less frequently and there are fewer failuresG).

It is also possible to visually detect the position of the tip of the welding torch and preset it in the setting device without using the copying mechanism.

Furthermore, with the conventional tracing mechanism, it becomes difficult to trace the layer near the final layer in multi-layer welding, but with the method of the present invention, the welding toe automatically traces the position that is memorized or preset before welding. be able to.

In addition, detectors are installed at the welding start and end positions, and the welding torch tip position for each layer is memorized, and welding conditions such as welding current, arc voltage, and welding speed for each layer are simultaneously preset. Multilayer arc welding can also be performed fully automatically according to the method.

According to the longitudinal welding or circumferential welding method for large and heavy objects according to the present invention, welding distortion can be reduced, the burden on the operator can be reduced, and multilayer arc welding can be performed efficiently.

In particular, in the method of the present invention, it is only necessary to correct the welding torch at each dividing point, and there is no need to correct the orientation, so the structure of the device is simplified and workability is improved, which is preferable.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams for performing longitudinal seam welding according to the present invention when the center line of the bevel processing of the workpiece, such as a cylindrical pressure vessel, and the advancing direction of the welding torch are not parallel. Figure A is a plan view, Figure C is an enlarged cross-sectional view of the groove, Figure 2 is an explanatory diagram showing another embodiment, and Figure 3 is a cross-sectional view as seen from the side. An embodiment of the welding method according to the present invention is shown in a case where the welding device moves on a fixed rail and it is difficult to set the center line of beveling a large heavy object parallel to the direction of movement of the welding device. FIG. 4 is an explanatory diagram showing the position of the tip of the welding torch and the bead surface of each layer when performing multilayer welding. a...Joining line (approximately straight line), b...Beveled end, γ...Progressing direction of the welding device,
1... Work to be welded, 2... Welding torch,
3...Welding wire, A~1...Position of the welding toner tip at the welding start position of each layer, a~B...
・・・・Surface of weld bead of each layer.

Claims (1)

[Claims] 1. Vertical joints or circumferences of objects to be welded, which are large and heavy objects that are difficult to set so that the locus of the tip of the welding torch and the center line of the beveling match or are parallel to each other. In the welding method, the center line of the beveling process is divided into a plurality of parts in advance before welding of the workpiece is started, and the position of the tip of the welding torch and the center line of the beveling process are approximately equal to each other at each dividing point. The position of the welding torch is determined for each division point so that there is a constant positional relationship, and the position is stored in a storage device or preset in a setting device and saved. During welding, the welding start position and the next division point are stored. Welding is performed without correcting the position of the welding torch between the welding points, and at each dividing point, welding is continued toward the subsequent dividing point after the position of the welding torch is corrected to the saved position, A longitudinal or circumferential welding method for large and heavy objects, characterized in that welding is performed without adjusting the position of a welding torch between each dividing point. 2. In a method of vertically welding or circumferentially welding a workpiece consisting of a large and heavy object in which it is difficult to set the locus of the tip of the welding torch and the center line under the groove QD to be coincident or parallel. , Prior to the start of welding the object to be welded, each position of the welding torch at the welding start position of each layer is preset in a setting device, and the center line of the groove processing is divided into a plurality of parts, and at each dividing point. The position of the welding torch is determined for each dividing point so that the position of the tip of the welding torch and the center line under the groove 7JD has a substantially constant positional relationship, and the position is stored or set in a storage device. When welding the first layer, welding is performed without correcting the position of the welding torch between the welding start position and the next dividing point, and at each dividing point, the saved position is The position of the welding torch is automatically corrected so that Then, for the second and subsequent layers, the welding torch is automatically moved to the welding start position that was preset before starting welding of the first layer, and then welding is started. Correcting the position of the welding torch at each division point so that the welding torch is at the memorized or preset position in the same way as for the layers, and performing welding of each layer without correcting the position of the welding torch between each division point. A longitudinal or circumferential welding method for large and heavy objects.