JPS5844956Y2 - Belt type backing device for welding - Google Patents

Description

[Detailed description of the invention] The present invention relates to a belt-type backing device for welding, and more specifically, in double-sided welding, it reliably prevents the so-called burn-through phenomenon in which molten metal flows toward the back side of the groove, and This invention relates to a belt-type backing device devised to form a good backing bead.

For example, when performing circumferential welding of steel pipes, there are three methods, as shown in Figure 1, in which the butt weld line is first welded from the inner surface to form an inward bead A, and then welded from the outer surface to form an outer bead B. will be adopted.

In this case, special care is required when forming the inner bead A. If the welding conditions at this time are inappropriate, the base metal 1 will melt at the outer circumferential side 1 of the groove, and the molten metal will not melt. Falling or burn-through phenomenon may occur.

Once the melt-through phenomenon occurs, a hole is created at that location, which requires an enormous amount of time to repair, and in some cases, the steel pipe itself may become unusable.

Therefore, when performing internal welding, there are three methods to apply backing flux to the outer surface of the groove as shown in Figures 3 and 4 to prevent the molten metal from flowing away even if the welding arc melts the base metal 1 too much. It is taken.

That is, FIG. 3 is a schematic explanatory diagram showing an example of inner surface butt welding of a steel pipe (base metal) 1, and FIG. 4 is an enlarged cross-sectional view showing the welded part shown in FIG. The flux holding belt 2 is stretched and arranged.

This belt 2 is pressed against the outer surface of the groove by a pressing roller 3 and rotates as the base material 1 rotates.

Therefore, when welding the inner surface, the flux 5 supplied from the flux hopper 4 can be supported on the holding belt 2, and the outer surface of the groove is supported by the flux 5, so that no welding phenomenon occurs. Nothing will happen.

Incidentally, the flux 5 that has passed through the welding portion falls from the rear end of the holding bell (2) and is collected in the collection hopper 6 to be reused.

However, if the backing method shown in Figures 3 and 4 is adopted, the weld metal burn-through phenomenon can be prevented as much as possible, and at least holes will not form in the groove weld during internal welding, but this The inventors recognized that there was a risk that some joint defects could occur.

That is, when welding an X groove or an inverted Y groove using the backing welding method as described above, if the flux 5 is pressed flat against the back side of the groove, the flux 5 will not be applied to the back side as shown in Fig. 5, for example. The groove is not sufficiently filled, resulting in a space C.

If the molten metal hangs down into the space C, it will form a protrusion in this area, and if welding is performed from the outside at this time, joint defects will likely occur, so it is necessary to cut off the hanging part A', reducing work efficiency. There was the problem of inviting

However, when performing this type of back welding, if the back groove is filled with flux 5, the formation of drooping parts can be prevented as much as possible, and the joint obtained by welding this from the outside can be avoided. It turns out that it can be extremely healthy and strong.

The present invention was made based on the above-mentioned knowledge, and the purpose is to develop a backing device that can reliably fill the back groove with flux during the backing welding process. The aim is to ensure that a healthy and strong joint can be stably obtained.

The configuration of the backing device of the present invention that achieves this purpose is as follows:
This is an improvement of the belt-type backing device as described above, and includes a flux support belt that deforms so that its approximately central portion protrudes toward the back surface of the groove due to pressing pressure toward the back surface of the groove, and both sides of the support belt. The gist lies in the fact that it is combined with an auxiliary belt that prevents flux from spilling.

In other words, in the backing device of the present invention, the substantially central part of the flux support belt is configured to protrude toward the back side of the groove due to the pressing force, so that the flux on this support belt is absorbed into the groove on the back side during the welding process. This prevents joint defects such as overlamp as shown in FIG. 5 from occurring.

In addition, if the central part of the support belt protrudes, the pressing force of the side force part will be weakened, and there is a risk that flux will spill from the side force part of the support belt and scatter into the work environment. Since the auxiliary belt is placed on the side, there is no risk of contaminating the work environment due to flux scattering.

The configuration and working effects of the present invention will be explained below based on the drawings which are examples. However, the embodiments described in the following examples and claims for utility model registration are merely representative examples, and the embodiments described in the preceding and following explanations are merely representative examples. Words that are implemented with appropriate changes in accordance with the purpose also belong to the technical scope of the present invention.

Figures 6 to 8 are cross-sectional explanatory views illustrating the backing device according to the present invention.The overall structure is almost the same as the example shown in Figure 3, and is configured in the shape of an endless belt. Pressed against the back of the groove.

The configuration of the endless bell Y section is the flux support bell) 7
and auxiliary bells f8 on both sides of the support belt 7 to prevent flux from spilling, and backing flux is deposited on the support belt 7.

Further, the support belt γ is configured to be pushed up toward the back surface of the groove independently of the auxiliary belt 8 when receiving a push-up force toward the blade shown in the drawing by a pressing roller as described later.

Therefore, as shown in FIG.
a, or as shown in FIG. 8, a pressing roller 3 that contacts only the support belt γ and urges its approximately central portion upward.
If you press the support bell ■1 against the blade shown in the drawing using
The flux 5 is filled in the back groove as shown in Fig. 8.

It goes without saying that the pressing roller 3 and the large diameter roller 3a may be formed separately.

That is, since no space C is left in the back groove as shown in FIG. 5, there is no possibility that molten metal will flow down into the back groove and cause joint defects when forming the inner bead A.

Moreover, since the auxiliary bells 8 are arranged on both sides of the support belt 70, there is no risk of the flux 5 leaking from the sides even if the support belt 1 is deformed during pressing.

9 and 10 are cross-sectional explanatory views showing an embodiment of the pond of the present invention. In this example, a protrusion 1a is formed on the substantially central lower edge of the support belt 7.

In this way, even if a simple cylindrical pressing roller 3 is used, the protrusion γa comes into contact with the roller 3 as shown in FIG. , the same effect as the example in FIG. 8 can be obtained.

The backing device of the present invention is configured, for example, as described above, but the gist is that when the backing flux is supported by the belt and pressed against the back surface of the groove, the support belt is attached to the groove at approximately the center of the backing flux. It is characterized by the fact that it protrudes in the direction of the force on the back side, and that auxiliary belts are placed on both ends of the support belt to prevent leakage of flux, increasing the packing density of flux on the back side of the groove to prevent gaps from forming. There is.

Therefore, as long as these features can be effectively exhibited, the shapes of the Franks support belt f, the auxiliary belt, the pressing roller, etc. are not limited to those shown in the drawings, and can be freely modified by those who implement the present invention.

In the example shown above, the explanation was given using the case of butt welding steel pipes, but it can of course be applied to butt welding of flat plates, and the welding position can also be applied to horizontal welding in addition to downward welding. .

As is clear from the above diagram, the backing device of the present invention is advantageous when welding one side of a joint with a groove on the back side, that is, double-sided groove butt welding (X groove, ■ groove, etc.). However, considering the effect of increasing the packing density of the backing flux and eliminating the gap on the back side of the groove, the supporting capacity of the flux is also increased when welding one side of a V-groove palm groove, etc. Therefore, it is advantageous.

The present invention is constructed as described above, and can enjoy various benefits as shown below, and its practical value is extremely great.

(1) Since the back groove can be reliably filled with backing flux, there is no fear that molten metal will enter the back groove, and joint defects such as overlap will not occur.

(2) There are auxiliary bells Y on both sides of the flux support bell I.
Because of this arrangement, flux does not leak to the sides during the pressing process, which prevents contamination of the working environment and eliminates waste of other flux.

(3) If the present invention is applied to single-sided groove butt welding, the back bead can be formed beautifully and soundly.

[Brief explanation of the drawing]

Figures 1 and 2 are partial cross-sectional views illustrating a double-sided groove butt welded joint, Figure 3 is a schematic side view illustrating a butt inner surface welding method for steel pipes, and Figures 4 and 5 are conventional methods using backing flux. Figures 6 to 10 are cross-sectional views illustrating the backing device according to the present invention, and Figures 6 and 9 are in the previous state of pressing, and Figures 1.8.10 are The figure shows the state in which flux is pressed against the back surface of the groove. 1... Base material (steel pipe), 2... Support bell Y, 3...
Pressing roller, 5...Flux, γ...Flux support belt, 8...Auxiliary belt.

Claims (7)

[Scope of utility model registration request] (1) A belt-type backing device that is placed on the back side of the base material to be welded and presses welding flux against the back side of the groove, and the approximately central part is directed toward the back side of the groove by applying pressure toward the back side of the groove. A belt type backing device for welding, which consists of a flux support belt that deforms so as to protrude, and auxiliary belts located on both sides of the support belt to prevent flux from spilling out. (2) The apparatus according to claim 1, which is a device in which a flux retaining wall is provided at both ends of a flux support belt. (3) The device according to claim 2, wherein the retaining wall of the flux support belt has a cross-sectional height lower than that of the auxiliary belt. (4) The device according to claim 1.2 or 3, wherein the flux support belt is an endless belt that rotates according to the movement of the welded material. (5) The device according to any of claims 1 to 3 or 4, wherein the welded portion is a butt welded portion of steel pipes, and is arranged on the outer peripheral side of the welded portion. (6) The apparatus according to any of claims 1 to 4 or 5, wherein the flux support bell f is pressed by a roller disposed on the back surface of the belt. (7) The device according to claims 1 to 5 or 6 of the utility model registration, which is a backing device for double-sided welding used when the material to be welded has a groove on the backing side.