JPS5910869B2 - Non-consumable electrode all-position automatic welding equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an all-position automatic welding device for welding the entire circumference of a fixed pipe by the TIG arc welding method, which uses a non-consumable electrode and covers the welded part with an inert gas. be.

Figure 1 shows an automatic welding device that welds the entire circumference of a fixed pipe.
In the figure, 1 is a welding torch, 2 is a welding torch 1 on the welding line.
3 is a conduit tube that guides the filler wire, 4 is a filler wire feeding motor,
5 is a reel for winding the filler wire; 6 is a ring gear for rotating these welding torch parts around the fixed tube 8; T is a welding head housing for mounting each of the devices 1 to 6 above on the fixed tube 8; 1 -T are collectively called the welding head.

By the way, since fixed pipes are welded 15 times after the pipes are assembled, there are often obstacles around the pipes.
It is desirable that the welding head be as small as possible.
Therefore, welding torches, wire feeding devices, etc. are also becoming smaller.

On the other hand, high quality and high work efficiency are required in terms of welding work, and although satisfactory results have been obtained in terms of quality,
The current situation is that it cannot be said to be sufficient in terms of work efficiency. Work efficiency is determined by the welding speed per unit time, and the welding speed is proportional to the amount of filler metal (filler wire) welded. In order to increase the amount of welding, it is necessary to increase the thickness of the filler wire or increase the wire feeding speed. Generally, the appropriate thickness of the filler wire is about 0.8 to 1.2n, and if it becomes thicker than this, the rigidity of the wire will increase, and the capacity of the wire feeding motor will need to be increased.
This has the disadvantage that the wire feeding device becomes larger. FIG. 2 is an explanatory diagram of the welding situation, and in the figure, 9 is an electrode, 10 is a nozzle, 11 is a filler wire, 12 is an arc, and 13 is a molten pool, and shows the case where they are in an upward orientation. Generally, in the case of all-position welding,
In order to prevent the wire from melting 35, it is necessary to insert one end of the wire 11 into the molten pool 13 as shown in FIG. 2b, rather than directly under the arc as shown in FIG. 2a. As a result, the wire 11 receives heat from the molten pool 13 and melts. As the wire is melted by the heat of the molten pool, when the wire feeding speed exceeds a certain speed, the wire 11 melts before it melts in the molten pool. As shown in FIG. 3, the wire remains unmelted in the molten pool, resulting in a welding defect. In the figure, 14 indicates the unmelted wire. Such a tendency is noticeable when a pulsed current is used for the welding current or when welding is performed by vibrating the arc from side to side, since the size of the molten pool changes. As described above, there is a risk that welding defects will occur if the wire feeding speed is too high, so there is a limit to increasing the wire feeding speed in order to increase the welding speed. The purpose of this invention is to improve the above-mentioned drawbacks, and by feeding a plurality of filler wires, it is possible to avoid increasing the rigidity of the filler wire and without increasing the wire feeding speed.
The present invention provides a non-consumable electrode type all-position automatic welding device with high quality and high work efficiency.

4, 5, and 6 show an embodiment of the present invention. Reference numeral 15 denotes a reel for winding two filler wires 11 in sections. Denoted at 16 and 17, which are taken out as a set, are feeding rollers that transfer the two filler wires 18 while pressing them, and form two guide grooves 10 for guiding the filler wires 11 on the outer peripheral surface.

20 is a conduit tube that guides the filler wire 18 fed by feeding rollers 16 and 17 to the welding part.

With the above configuration, twice the amount of welding can be obtained at the same feeding speed, and since the thickness of the filler wire is not increased, the rigidity cannot be increased and the feeding rollers 16 and 17 are driven. There is little need for an increase in the capacity of the wire feeding motor.

Furthermore, since the guide grooves 19 for guiding the respective filler wires 11 are provided on the outer circumferential surfaces of the feed rollers 16 and 17, the contact area between the filler wires 11 and the feed rollers 16 and 17 can be increased, making it possible to increase the feeding speed. It can be done smoothly.
In addition, in the case of a welding method in which the arc is vibrated in a direction perpendicular to the welding direction, two filler wires are arranged in parallel rather than one filler wire having the same cross-sectional area as shown in Figure 7b. The method shown in Figure 7a allows the molten metal to spread to the left and right more effectively. It is especially difficult to cause drooping of the molten metal and extremely convex beads that tend to occur during upward welding, and welds in all positions. For this purpose, higher quality is obtained than a single filler wire with the same cross-sectional area.

In the above embodiment, two filler wires are used, but it is also possible to use two or more filler wires.

As described above, the device of this invention can feed the wire without making the wire feeding device larger than the current size in the welding head for pipe welding, which has many obstacles around the pipe and requires miniaturization. Welding efficiency can be greatly improved compared to conventional welding without sacrificing performance, and high-quality welded products can be obtained that spread the arc and prevent welding defects.

[Brief explanation of the drawing]

Figure 1 is a perspective view of an all-position automatic welding device for fixed pipes, Figure 2 is an illustration of arc welding in an upward welding position, Figure 3 is an illustration of occurrence of welding defects, and Figures 4 to 7 are of this invention. 4 is a perspective view of the filler wire wound on a reel, FIG. 5 is a perspective view of the filler wire feeding device, FIG. 6 is a front view of the feeding roller, and FIG. 7 is the same. FIG. 3 is a comparison diagram of a filler wire having a cross-sectional area and a wire according to the present invention during welding; In the figure, the same reference numerals indicate the same or corresponding parts, 8 is a fixed tube, 9 is an electrode, 16 and 17 are feeding rollers, 18 is a filler wire, 19 is a guide groove of the feeding roller, and 20 is a conduit tube. .

Claims (1)

[Claims] 1. In an all-position automatic welding device that welds the entire circumference of a fixed tube using a non-consumable electrode and enveloping the welded part with an inert gas, a single wire reel in which multiple filler wires are wound separately; It is equipped with one feed roller provided with the same number of guide grooves as the number of filler wires, and one conduit tube that simultaneously guides the plurality of filler wires to the welding part, and is wound on the wire reel. A non-consumable electrode type automatic all-position welding device, characterized in that a plurality of wires are simultaneously fed to the welding part.