JPH06142929A - Method and equipment for automatic welding - Google Patents

Abstract

PURPOSE:To continuously perform automatic welding along a joint line from a corner part of a structural body. CONSTITUTION:In the automatic welding equipment A having an elevating and lowering guide 1 to travel along the joint line L, an oscillator 6 to oscillate in the orthogonal direction to this elevating and lowering guide 1 and a welding torch 8 to oscillate by this oscillator 6, a welding torch rotation mechanism 12 which rotates up to a specified angle along the joint line L and stops rotation of the welding torch 8 when the specified angle is attained is provided between the oscillator 6 and the welding torch 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method and a welding apparatus for continuously and automatically welding a structure having a corner where an end of a joint line interferes with the welding apparatus. It is a thing.

[0002]

2. Description of the Related Art Conventionally, a flat-bottomed cylindrical tank, for example, L
When automatically welding the side plates of the NG ground type storage tank, automatic TIG welding (tungsten-inert-gas arcweldin) as shown in Fig. 8 is used.
g) There is a method of performing automatic welding using the device. In this method, in the welding of the vertical joint portion 52 of the side plate 51, the automatic welding device 53 provided in the vertical direction automatically welds from the lower side to the upper side along the elevating guide 54, but at the lower end portion, Since the annular plate 55 interferes with the welding device 53, automatic welding cannot be performed on the lower end portion of about 500 mm, and it is necessary to provide the unwelded portion 56. Further, since the joint portion 52 of the general side plate 51 has a wide groove, it is necessary to repeat welding a plurality of times. Therefore, the welding residual portion 56 becomes a large welding residual portion. Then, the unwelded portion 56 at the lower end was inevitably subjected to manual welding by the covered arc welding method (hereinafter, referred to as Conventional Example 1).

In order to automatically weld all the vertical joints 52, a bracket 57 is provided on the side plate 51 as shown in FIG. 9, and a jack 58 is interposed between the bracket 57 and the annular plate 55 at the bottom. Then, by jacking up the entire side plate 51 with this jack 58,
There is also a method in which a gap is provided between the annular plate 55 and the annular plate 55, the side plate vertical joint portion 52 is automatically welded in this state, and then the side plate 51 is jacked down (hereinafter referred to as Conventional Example 2).

As a conventional technique of this kind, Japanese Patent Laid-Open No.
Although there is an invention described in JP-A-101240, the invention described in this publication is an invention for continuously and efficiently performing horizontal fillet welding which intersects with each other, and a horizontal direction in which a bottom plate and a torch intersect at a predetermined angle. The present invention does not make it possible to perform continuous automatic welding along a joint line which is a butt joint in the vertical direction from a corner unlike the present invention.

[0005]

In the above-mentioned conventional example 1, it is necessary to provide a welding residue at the lower end portion, and when the joint portion 52 provided with this welding residue portion 56 is manually welded by covered arc welding or the like, A joint between the automatic welded portion and the manual welded portion is generated, and the joint quality is deteriorated at this joint portion. Especially, in the case of the LNG ground type storage tank, the welding material for automatic welding and the welding material for manual welding are Since the system is different, it is necessary to adjust the imaging conditions in the radiation transmission test after welding. In addition, the efficiency of construction is deteriorated by switching between automatic welding and manual welding.

Further, in the above-mentioned conventional example 2, in order to form the joint portion 52 which the welding device does not interfere with the side plate 51 which is the structure before welding, the side plate 51 is provided with the bracket 57 and the bracket 57 is provided with the jack 58. It is necessary to insert and jack up, and in this case, the cylindrical side plate 51
Many jacks 58 because it is necessary to raise the
And needed to work while controlling them. Further, in this case, after the jack 52 is once jacked up and the joint portion 52 is automatically welded, the structure is required to be changed before and after welding in order to jack it down and return it to the original structure. Therefore, the construction period becomes long and This raises the problem of increasing costs. Further, in this case, there is a safety problem when changing the shape of the large structure.

Further, in the case of a large-sized structure, there are ten or more joint portions 52 on the circumference, so all of these joint portions 5
It is necessary to perform the automatic welding work on the No. 2 according to the above-mentioned conventional example 1 or the conventional example 2, which requires a lot of working time and a great cost.

In view of the above problems, it is an object of the present invention to provide a method and a welding apparatus for automatically welding a corner of a structure and continuously performing automatic welding along the joint line from the corner. And

[0009]

In order to achieve the above object, an automatic welding method according to the present invention holds a welding torch at an angle facing a corner and uses the welding torch to weld the corner while welding the torch. Rotate and rotate to a predetermined angle while keeping the distance between the welding torch and the member to be welded constant, and when the predetermined angle is reached, stop the rotation of the welding torch and perform welding while running the welding torch along the joint line. It is characterized by.

Further, the automatic welding apparatus of the present invention comprises a traveling means for traveling along the joint line, an oscillating means for oscillating in a direction perpendicular to the traveling means, and a welding torch for oscillating by the oscillating means. In the automatic welding apparatus having, between the oscillating means and the welding torch, rotate up to a predetermined angle along the joint line,
It is characterized in that a welding torch rotating mechanism for stopping the rotation of the welding torch when a predetermined angle is reached is provided.

[0011]

According to the automatic welding method having the above-mentioned structure, the corner is welded while being rotated by the welding torch that holds the corner at an angle, and at the same time, the distance between the welding torch and the member to be welded is kept constant. While rotating to a predetermined angle. When the predetermined angle is reached, the welding torch stops rotating and runs along the joint line to automatically weld the joint line.

Further, according to the automatic welding apparatus having the above-mentioned structure, the welding torch rotating mechanism provided between the oscillating means and the welding torch performs welding while rotating the welding torch, and when the welding torch reaches a predetermined angle, welding is performed. While stopping the rotation of the torch, the joint line is welded while traveling along the joint line by the traveling means. When welding this joint line, welding is performed while oscillating by an oscillating means for oscillating in a direction perpendicular to the traveling means.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view showing the entire automatic welding apparatus of the present invention, and FIG. 2 is a plan view showing the automatic welding apparatus. In addition,
In the following description, automatic welding of a butt joint having a vertical joint line (groove) L will be described as an example.

As shown in the figure, a vertical guide 1 which is a traveling means of the automatic welding apparatus A is provided in the vertical direction of the side plate B which is a structure.
Are provided, and the elevating guide 1 is fixed above and below the side plate B. An elevating member 3 that elevates and lowers by a guide shaft 2 provided in a central portion is provided inside the elevating guide 1.
The guide member 4 is fitted into the guide member 4 provided therein.
It is configured to move up and down while sliding along. Further, the elevating member 3 is provided with an oscillator 6 which is an Oscillate mechanism via a transverse guide 5 for adjusting the lateral position in the direction perpendicular to the joint line L direction. It is configured to vibrate the shaft 7 with a predetermined amplitude in a direction orthogonal to the axial direction of the elevating guide 1.

On the other hand, the welding torch 8 has a control unit C.
A welding cable 9 from a welding machine provided inside is connected, and a wire cable 10 from a wire feeding device (not shown) is supplied. The welding torch 8 is made of A. V. C. 11 (Auto Voltage Controller;
The controller 11 is connected, and is controlled by the controller 11 so as to always maintain a constant distance from the voltage change due to the distance between the tip of the welding torch 8 and the side plate B (base metal). Incidentally, D is a control box for controlling the ascending / descending position and the like.

A welding torch rotating mechanism 12, which is a means for rotating the welding torch 8 together with the controller 11, is provided between the oscillator 6 and the controller 11 of the automatic welding apparatus A having such a configuration. The welding torch rotating mechanism 12 is fixed to the end of the shaft 7 of the oscillator 6, and the controller 11 is fixed to a mounting plate 13 protruding from the welding torch rotating mechanism 12.

By providing the welding torch rotating mechanism 12 between the oscillator 11 and the controller 11 for adjusting the distance between the welding torch 8 and the side plate B in this way, the welding torch 8 and the side plate B are changed by rotating them. The distance can be easily adjusted by the controller 11.

The welding torch rotating mechanism 12 will be described below with reference to the side view shown in FIG. 3 and the front view shown in FIG. As shown in the figure, a drive motor 15 is fixed to the casing 14 of the welding torch rotation mechanism 12, an output shaft 15a of the drive motor 15 is provided so as to project into the casing 14, and a gear 16 is attached to the output shaft 15a. It is fixed. An intermediate shaft 19 that supports a gear 17 that meshes with the gear 16 and a worm gear 18 that is provided in parallel with the gear 17 is supported by the casing 14. On the other hand, a rotary shaft 21 that supports a worm wheel 20 that meshes with the worm gear 18 is provided in a direction orthogonal to the intermediate shaft 19, and the controller 11 is fixed to one end of the rotary shaft 21. Is provided with a mounting plate 13 of
A lever 22 for actuating a limit switch 23 (FIG. 2) is provided at the other end.

The power of the drive motor 15 is transmitted from the gear 16 to the gear 17, the worm gear 18, the worm wheel 20, and the rotary shaft 21. As shown in FIG. 13 is rotated,
The controller 11 and the welding torch 8 rotate about the rotation center E. The rotation of the rotary shaft 21 rotates a lever 22 provided at the end of the rotary shaft 21, and when the lever 22 reaches a predetermined angle, a limit switch 23 operates and is driven by a signal from the limit switch 23. The motor 15 is configured to stop.

Further, the automatic welding apparatus A constructed as described above, as shown in the overall view of FIG. 5, has an apparatus control unit, a wire feeding control unit, a welding power source, a cooling water provided in the control unit C. It is connected to a pump or the like, and is configured to perform automatic welding by controlling the welding torch 8 via the control box D or directly by a signal from the device control unit.

An automatic welding procedure by the automatic welding apparatus configured as described above is shown in a partially enlarged view of FIG. 6 and the above-mentioned FIG.
The following description is based on the side view of FIG.

First, at the start of welding, as shown in the figure, the welding torch 8 is set so that the tip thereof faces the corner, and the oscillator 6 is used to set a predetermined oscillator corresponding to the joint line (groove) which is the butt joint portion of the side plate. At the same time when the welding torch 8 is rotated, the welding torch rotating mechanism 12 rotates the welding torch 8 about the rotation center E as the axis to perform welding. That is, the rotation angle θ of the normal welding torch 8 is an angle at which the tip of the welding torch 8 facing the corner rotates to an angle substantially orthogonal to the joint line L. At this time, since the distance between the tip of the welding torch 8 and the side plate B changes with the rotation of the welding torch 8, the controller 1 rotates with the rotation of the welding torch 8.
The welding torch 8 is retracted by 1. Then, when the welding torch 8 rotates to the position of, the limit switch 11 operates to stop the rotation, and thereafter, the automatic welding proceeds while rising along the joint line L while maintaining the position of the welding torch 8 thereafter. These operations are performed sequentially, and are automatically controlled by signals output from the control unit C.

The above is the basic automatic welding method according to the present invention. As an application example using the automatic welding apparatus of the present invention, a new welding bead from a welded bead as shown in a partially enlarged view of FIG. The bead splicing construction will be described below.

That is, the weld bead 24 that has already been welded is diagonally shaped, and the welding torch 8 is formed as shown in FIG.
The new welding 25 is performed along the inclination of the front welding bead 24 while changing the angle of the welding end portion (crater) 2
6 is treated as a swell on the surface of the side plate B, and this swell is removed after welding. By welding in this manner, it is possible to perform work without leaving the crater 26 that is apt to cause welding defects such as weld cracks in the weld bead joint portion.

As described above, according to the present invention, since the seam between the automatic welding portion and the manual welding portion as in the conventional case is eliminated, the deterioration of the joint quality at the seam portion is eliminated and the automatic welding process is performed. There will be no deterioration in construction efficiency due to switching of manual welding construction. Further, since it is not necessary to change the shape of the structure before and after welding, the construction period or cost is reduced, and the safety problem is eliminated.

The above-described embodiment shows an embodiment in which TIG welding is performed, and the welding torch 8 and the side plate B are shown.
Controller 11 that keeps a constant distance from the member to be welded
Is provided so that the distance between the tungsten electrode and the side plate B which is the member to be welded can always be kept constant.

In the above embodiment, the vertical joint line C is welded from the lower side to the upper side. However, the joint line C may be welded in the right and left directions, and the same applies to welding of a welded member having a corner. Automatic welding is possible.

Further, the elevating guide 1, the transverse guide 5, the oscillator 6, and the controller 11 described above may be already used.

[0029]

According to the present invention, automatic welding can be continuously performed from the corners of a structure, and as a result, no welding residue is left at the corners of the structure. No joints with the parts are generated, the joint quality is improved and the construction efficiency is also improved.

Since the shape of the structure is not changed before and after welding as in the conventional case, it is possible to shorten the construction period required for welding and reduce the cost.

[Brief description of drawings]

FIG. 1 is a side view showing the entire automatic welding apparatus of the present invention.

FIG. 2 is a plan view showing an automatic welding device of the present invention.

FIG. 3 is a side view showing a welding torch rotating mechanism of the automatic welding apparatus according to the present invention.

FIG. 4 is a front view showing a welding torch rotating mechanism of the automatic welding apparatus according to the present invention.

FIG. 5 is a schematic view of the entire welding apparatus when the automatic welding apparatus of the present invention is used.

FIG. 6 is a partially enlarged view showing a mode of use of the automatic welding apparatus of the present invention.

FIG. 7 is a partially enlarged view showing another usage mode of the automatic welding device of the present invention.

FIG. 8 is an overall perspective view showing a construction example by a conventional automatic welding device.

FIG. 9 is an overall perspective view showing another example of construction by a conventional automatic welding device.

[Explanation of symbols]

 1 ... Lifting guide 2 ... Guide shaft 3 ... Lifting member 5 ... Traverse guide 6 ... Oscillator 7 ... Shaft 8 ... Welding torch 11 ... Controller 12 ... Welding torch rotating mechanism 15 ... Drive motor 18 ... Worm gear 20 ... Worm wheel A ... Automatic Welding device B ... Side plate E ... Rotation center L ... Joint line

Claims (2)

[Claims] 1. A welding torch is held at an angle facing a corner,
The welding torch is rotated while welding the corner portion, and further, the welding torch is rotated to a predetermined angle while keeping the distance between the welding torch and the member to be welded constant, and when the predetermined angle is reached, the rotation of the welding torch is stopped and welding is performed. An automatic welding method characterized in that welding is performed while a torch is running along a joint line. 2. An automatic welding apparatus comprising: a traveling means for traveling along a joint line; an oscillating means for oscillating in a direction perpendicular to the traveling means; and a welding torch oscillating by the oscillating means. An automatic welding apparatus comprising: a welding torch rotating mechanism which is provided between an oscillating means and a welding torch and which rotates along a joint line to a predetermined angle and stops rotation of the welding torch when the predetermined angle is reached.