Description :: Our patents

The guessed invention falls into field of laser welding and can be used for running of long distance pipelines of different assignment in field requirements, specially in northern regions.

The installation for laser welding of long distance pipelines is known [1]. The installation is the overlapping tube construction, which comprises drive unit and mechanism of transposition along a tube, technological laser with a focusing lens and with rotation drive unit around a tube. Power supply and management of installation is carried out with an independent complex, moving on a soil together with the installation near a tube. The connection between installation and complex is ensured with communications lead unit.

The installation operates as follows. The tube, intended for a welding, is joined in place of its end with pipeline end. Further installation, using natural drive unit and mechanism of transposition, moves along pipeline end up to a junction place. The focusing lens is erected precisely opposite of junction. The laser is switched on and simultaneously with it is switched on laser rotation drive together with a focusing lens. The circular seam welding is carried out. After welding process holding the laser is switched off, and installation together with independent complex moves up to the following junction. After that the work cycle is iterated.

The installation for laser welding of pipelines is known [2]. The installation includes mobile device, platform with technological laser, disposed on it, control equipment, power station, added equipment. Its composition includes a box of beam guides with arranged on them tubes, intended for a welding, and device of tube contraction to the pipeline.

The installation operates as follows. The box with beam guides and intended for welding tubes brings an end of one tube to pipeline end, anchored in clamps.

With the help of contraction device is carried out a tube contraction to pipeline end. After that the laser is switch on and the radiation through a beam guide moves on a rotary mirror. Further it moves on a focusing lens and then - on welded junction. After circular seam welding the installation drives forwards on distance, equal tube length. The box of beam guides gives to a welding zone a new tube with a beam guide and work cycle is iterated.

Common fault of above described installations is unilateral technique of circular seam welding: in the first case - outside, in the second case - internal. The result is - non-quality welded joint, due to presence major stress concentrations, strains, flaws, and also flaws in the form of inserts in a seam root.

All this can bring to welded joint damage and, therefore, to breakage of the pipeline with major material losses.

Besides, the unilateral technique of welding allows providing welding of tubes of particular, restricted width. And now there is a stable tendency to application of pipelines with increasing operating pressures and, therefore, to usage of major thickness tubes.

A bilateral technique of laser welding is known [3]. The given technique allows providing seams forming of necessary configuration, that essentially reduces all above mentioned flaws.

Problems, solved by offered invention, are: an improvement in quality of welded seams and an improvement of welding complex efficiency.

The above-stated problems are solved by, that in a laser complex for pipelines running in a place of tube end junction with pipeline end on an exterior side there is an added laser, having rotation drive around of the junction. Between arranged on a beam guide lens (inside a tube) and an exterior lens concerning a tube axis there is an angle, which defines by technological requirements.

The power of the added laser can be equal or substantially greater, than laser power, providing welding of an interior root seam. It is known, what exactly flaws in a seam root define strength of all welded joint, therefore inside weld should be fulfilled whenever possible flawless. It is known, that quantity of seam flaws, and also stretching stresses in near seam zone of thermal influence are diminished with magnification of welding speed. Therefore it is important to provide the greatest possible welding speed of an inside weld, even at the expense of penetration depth. Stayed major part of tube wall thickness can be welded on smaller velocity with the exterior added laser. To increase productivity of process, it is possible to weld outside seam at once with several beams. For this purpose the added laser is necessary to fulfill multi- beamed, supplied with relevant quantity of focusing lenses, oriented on radiuses, concerning an axis of the pipeline and equidistant from each other on an angle.

The complex looks like this (fig.1). To the mobile device 1 the platform 2 is attached, on which are disposed independent power station 3, control equipment 4, added equipment 5 (gas system), the laser 6. From the technological laser the radiation is taken away with the help of an exterior beam guide 7. On a platform is disposed the box 8 of beam guides 9 with the intended for welding tubes 10. The box has transposition drive unit 11 and tube contraction device to the pipeline 12. On the end of each beam guide 13 are disposed the mechanism and drive unit of transposition along tube axis 13 (figs. 2 and 3), rotary mirror 14, focusing lens 15 and lens rotation drive around of tube axis 16. In a place of tube junction with the pipeline on an outer side disposes the exterior lens 17, hardly joint with the laser 19, having rotation drive around a tube 18. The laser 19 gives radiation to a lens 17.

On a platform are disposed legs 20, which hold and simultaneously center the pipeline end 21.

The complex operates as follows. On before made route of the future pipeline is moved the mobile device 1 together with the platform 2, coupled with it. On a platform, in its forward part are disposed the independent power station 3, control equipment 4, added equipment 5. Generated by technological laser 6 radiation are guided on an exterior beam guide 7, having a rotary mirror. Further radiation falls in a beam guide 9 and transports through it on a rotary mirror 14, being reflected from which one is guided to a focalizing lens 15. In it radiation is focused and guided immediately on the junction. The rotating of a focusing lens together with a rotary mirror around of an axis of welded tube is ensured with a drive unit 16. Thus the rooted seam is welded. Welding with an exterior focusing lens 17 is carried out on some distance from welding spot of a lens 15 (figs. 4) (angle a ). Also is possible the simultaneous welding of interior and outside welds, in this case a = 0. The focusing lens 17 takes radiation from technological laser 19, which has rotation drive 18 around of a tube. Forming of an outside weld happens on hot interior. After realization of circular seam double welding transposition drive unit 13, focusing lens and rotary mirror move to the right, thereby diminishing length of a beam guide.

The complex moves forwards on length of one tube. Further box of beam guides 8 with the help of a drive unit 11 brings a new tube10, intended for a welding, to the pipeline end 20. The pipeline end is supported and centered with the help of legs 21 concerning a welded tube. The device of tube contraction to the pipeline 12 contracts a tube to the pipeline end. The transposition drive unit 13 of a focusing lens moves it to the left up to a junction place. After that the operation work cycle is iterated.

Usage of bilateral laser welding of unwieldy constructions allows precisely centering them to one another and, therefore, creating requirements of weld forming.

What is claimed is:

A laser complex for long distance pipeline running, comprising mobile device, platform with disposed on it independent power station, control equipment, technological laser, added equipment, exterior beam guide, box of beam guides with disposed on them, intended for a welding tubes, and natural drive unit, and also anchored on the end of each guide focusing lenses and rotary mirrors, device of tube contraction to the pipeline, legs with the pipeline end, anchored in them, characterized in that between box of beam guides and legs, anchoring pipeline end, is arranged an added laser, overlapping pipeline end and welded tube, an output radiation from which is guided in exterior, in relation to a tube, focalizing lens, and this added laser together with a lens is fulfilled with an opportunity of rotating around of pipeline and tube junction and welding of an exterior weld.
The laser complex according to claim 1, wherein between focalizing lens, disposed on the beam guide end and focalizing lens, disposed on junction exterior side is present an angle.
The laser complex according to each of claims 1 and 2, wherein the added laser has power substantially major, than laser, providing interior rooted seam.
The laser complex according to claim 3, wherein the added laser has number of output beams, greater than 1, and relevant to them focusing lenses, equidistant from each other on a corner.