Description :: Our patents

The guessed invention falls into field of laser welding and can be used for pipelines running in field requirements.

Laser welding complex for manufacture continuous pipeline is known [1]. Distinctive feature of a complex is that all its equipment disposes inside welded pipeline. The complex comprises technological laser, optic-focusing system with a drive unit of its rotating, control system, fuel stock, drive, generator, which is working out electrical energy, necessary for independent operation of given welding complex. From all systems of laser pipe welding complex the greatest power consumption has technological laser. Technological laser for welding tubes by width 10¸ 25 mm should has an output power of radiation not less 20 kW and consumed power about 400 kW. For manufacture such high-power in an independent laser complex should be used dimensional drive, generator, cisterns with fuel, laser. The complex management at its motion on the pipeline, and also during welding, is carried out independently.

Disadvantages of given complex are construction complexity, major dimensions. As a result a welding of only major diameter tubes is possible, and complex reliability is rather low.

It is known the installation for laser welding of pipelines [2], which we have taken as prototype. The installation includes moving device, platform with technological laser, disposed on it, control equipment, power station, added equipment. Its composition also comprises a box with tubes, intended for a welding, beam guides, arranged inside tubes, with rotary mirrors and focusing lenses, disposed on their ends, and device of tube contraction to a pipeline.

The installation operates as follows. The box with beam guides and tubes, intended for a welding, with the help of self drive unit delivers an end of one tube to pipeline end, anchored in clamps. With the help of contraction device is carried out tube contraction to pipeline end. After that the laser is switched on and the radiation through beam guide moves on rotary mirror. Further it moves on focusing lens and then on welded junction. After circular seam welding the installation drives forwards along pipeline track on distance, equal length of a tube. The box of beam guides gives to a welding zone a new tube with the beam guide and the work cycle is iterated.

Disadvantages of the prototype are:

Major length of an optical channel, that in aggregate with lengthy, console anchored beam guide carries on to distortion of wave front and complexity of precise radiation directing on welding junction because of beam guide vibrations and mechanically bound with it welding head.
Composite and expensive construction of box, having in each seat a separate beam guide, on the end of which focusing lens and rotary mirror is anchored.

The problem, solved by offered invention, is reliability increasing at the expense of simplification of its construction, and quality improvement of welded seam at the expense of vibration diminution of complex optical devices.

The above-stated problem is solved by that in installation for laser welding of pipelines welding head is inside the pipeline and moves independently simultaneously with a platform, carrying technological laser and tubes, intended for a welding. While the installation comprises moving drive, platform with high-power laser, control equipment, power station, added equipment, tubes box and mechanism of tube contraction to the pipeline. Welding head comprises focusing lens, rotary mirror, a device for seam gas protection and cylinder with protective gas.

The technological laser is on another side of a platform from welded tube or box of tubes, than welding head.

The welding head has wheels, which are in contact with pipeline interior surface. The welding head has storage cell, drive and executive elements of transposition inside the pipeline, independent system of focusing beam induction on the junction. It includes data unit of junction position determination, system of a superposition of laser beam optic axis and optic axis of welding head, and also device for gas protection of welded seam and cylinder with protective gas.

The information transfer between laser control system and welding head is carried out with the help of an auxiliary laser radiation on a wave length distinguished from a wave length of power laser beam. For example, if for welding will be used high-power CO₂- laser on wave length10,6 microns, for communication it is convenient to use radiation of visual or short-range IR interval, generated, for example, with laser diodes.

The installation looks like this (fig. 1). Moving device 1 transits a platform 2 along before readied route. On a platform are arranged control system 3, independent power station 4, power supply and added systems 2 of technological laser 5. The box 6 with tubes 7, disposed in its seats, has a drive unit (is not shown) and also the mechanism of tube contraction to the pipeline (is not shown).

The box of tubes can have a various quantity of seats, for example, 2 for tubes of major diameter or 6 (and more) for tubes of smaller diameter. The replacement of tubes can be with the help of seat rotating concerning box axis, but the variant with parallel transposition in vertical or horizontal plane is possible also.

The composition of welding head 19 comprises focusing lens 15, rotary mirror 16, drive unit 17 of their rotating around of an axis of the pipeline 18.

For transposition on pipeline interior surface welding head has storage cell, drive with executive elements and wheels 20. The focusing lens has data unit of junction position determination 21, included in independent system of junction tracking and induction of power laser beam on the junction (is not shown), and drive unit of longitudinal travel 22. The pipeline end is disposed on clamps, set on a platform 8.

The installation operates as follows. The box 6 moves one of tubes 7, intended for a welding, to the pipeline 18 and centers them. The pipeline end is anchored in clamps 8. With the help of contraction mechanism (is not shown) is carried out the joining of tube and pipeline ends.

With the help of data unit of junction position determination 21 and drive unit of longitudinal travel 22 focusing lens 15 of welding heads 19 is erected precisely opposite of junction. Further at command of control system 3 technological laser 5 is switched, and power beams of high-power laser 10 is moved on rotary mirror 16, from which through focusing lens 15 is guided on welded junction. The rotation drive 17 ensures welding of circular weld. Also is possible a variant, when all welding head is rotated concerning tube axis. The connection between local control system of welding head and control system of laser complex is carried out on auxiliary laser (lasers) beam 24 with the help of data units 25. The complex energy delivery is ensured with power station 4.

After circular seam welding, at control system command the welding head 19 is moves independently on wheels 20 along pipeline track on tube length up to new junction place. The box 7 gives a new tube and centers it with pipeline end. The fine setting of focusing lens concerning the junction is realized with the help of data unit 21 and drive unit 22.

As contrasted with the prototype, power supply of basic elements is endured from a tube on a platform, that allows making it reliable and substantially simplify. Inside a tube there is only welding head with transposition device, which consume electrical power in many times smaller, than laser. It is possible to provide necessary storage of energy in storage cells, set together with a welding head. The installation dimensions is essentially diminished, its construction is simplified, box vibrations influence on seam quality is removed.

The application of such construction will allow making it maximum simple, improving reliability of its operations and increasing of weld quality in the pipeline.

What is claimed is:

A laser complex for welding pipelines, comprising a moving device with a platform, arranged on a platform high-power technological laser, power station, control system, box of tubes with mechanism of tube contraction to a pipeline and welding head, including a rotary mirror and a focusing lens, characterized in that the welding head is fulfilled independent, with an opportunity of arrangement and transposition inside the pipeline and with an opportunity of management with the help of commands transmission through a laser beam from laser complex control system, and is supplied with wheels, storage cell and drive unit of transposition along a tube and around of tube axis.
The laser complex according to claim 1, wherein it is supplied with the auxiliary laser for management of independent welding head, fulfilled with an opportunity of laser beam modulation with controlling wave length, distinct from wave length of high-power technological laser.
The laser complex according to claim 1, wherein it is supplied with the auxiliary laser, and the independent welding head is supplied with local control system, bound with laser complex control system through auxiliary laser beam.
The laser complex according to each of claims 1 – 3, wherein the independent welding head is supplied with the device for weld gas protection and cylinder with protective gas.
The laser complex according to each of claims 1 – 4, wherein the independent welding head is supplied with the data unit of junction position determination.
The laser complex according to each of claims 1 – 5, wherein the independent welding head is supplied with system of coordinate position determination of power laser beam concerning tube axis and adjusting system of axis attitude of this beam and of standing of independent welding head concerning the tube.
The laser complex according to each of claims 1 – 6, wherein the box of tubes is fulfilled with delivery opportunity of welded tubes to the pipeline end and is supplied with tubes delivery mechanism and with centering device of given tubes with the pipeline.