B 23 K 26/00

The guessed invention falls into fields of materials treating with the help of beam techniques and can be used for laser welding of pipelines in different assignments in field conditions: steppe, tundra, etc.

Known installation for laser welding of tubes with ring welds [1], includes optical system for laser radiation delivery from a laser to a welding zone. The optical system has 4 water-cooled mirrors: three- reflecting and one- focusing.

The installation operates as follows. A laser beam from a stimulus source is guided on the first mirror, being reflected from which is guided on the second mirror. The second mirror is movable and is arranged on a carrier, which in turn has an opportunity during welding to move around of a tube on half of its perimeter (180⁰). Being reflected from the second mirror, the beam falls on the third mirror, arranged on annular-shaped chariot, such as a cramp, orbital displaced around a tube on 360⁰. Being reflected from it, the beam is guided on the last focusing mirror, then falls immediately in a welding zone.

The given system has following disadvantages:

1. The beam channel has on the extent some water-cooled mirrors, that carries on to wave front distortion, to transformation of polarization during welding process, and therefore, to quality variability of welded joint on its extent. Besides, on each of mirrors a particular quantity of radiated power is absorbed and consequently for embodying process of welding it is required to brought more electric power. Besides, such architecture of laser beam circular transposition is implemented with the help of several unwieldy mechanisms – a carrier, an annular-shaped chariot such as a cramp, etc., that carries on to a bulk of all installation as a whole.
2. For embodying process of tubes welding there is necessary a transposition of installation, power supply station, technological laser, equipment of its operation security along a line of pipeline running. For the solution of this problem it is necessary to use some added all-purpose drive vehicles, truck tractors, etc., since an interleaf is carried on in requirements of impassable roads.
3. The transposition of laser processing equipment, optical systems in field requirements is combined inevitably with different kind of shaking, vibrations, etc. that carries on to a misalignment of such systems, as laser cavity, devices of an exterior optical channel, focusing optics. The added alignment of all above named systems is laborious operation, requiring major expenditures of time.
4. The operation of installation, comprising precise mechanical units of transposition, optical devices in conditions of atmosphere direct action (rain, snow, etc.), carries on to aggravation of complex operating performances and reduces its operation reliability.
5. The welding of tubes with major diameters can made with the help of high-power CO₂- lasers. In them for oscillation of necessary radiated power is carried out a pumping of working mixture with velocities about 100 m/sec. Mixture cooling in such lasers in steady-state conditions is made with the help of direct water flux from a main line with its subsequent pouring. The architecture of water rotation system in field requirements carries on to extraordinary bulk of all installation, and also to usage of added equipment -cisterns, added main lines, pumps, etc.

There is a welding complex for continuous pipeline manufacture [2].

The complex incorporates intratube welding tube with self drive unit of transposition and ladder–type rod, self-moving car with power station, control equipment, inductor, roller conveyer, container for intratube welding machine, platform with clamps, disposed on it. The tube, intended for welding, is erected in clamps, arranged on a uniform platform with clamps of pipeline end. An added centering of their ends is not required. After that, using self drive unit, intratube welding machine goes in a bore of welded tube, moves inside it up to a junction place, carries out circular seam welding. After welding ending intratube welding machine moves back to an output. Going out from a tube, it moves in the container. The welding complex moves forwards on tube length. Further is yielded a new tube charging, a centering concerning a pipeline and work cycle is iterated.

In complex composition is not entered a composite system of water-cooled mirrors, and therefore, all problems, combined with it, are excepted (see above). Besides, all processing equipment both for a centering of welded tubes and for holding immediately of welding process is disposed on a uniform platform.

The complex has following disadvantages:

1. For embodying process of pipelines welding in field requirements without composite optical system it is necessary to use an arc technique of welding instead of laser, that in practice carries on to sharp aggravation of weld operating performances and accordingly to lowering pipeline operation reliability.
2. There is a major part of an added time. For realization of a complete work cycle, intratube welding machine should doubly pass inside a tube on all its length, that demands expenditures of time. Thus the welding complex stands, as a holding of following operation – charging and centering of a tube is impossible.
3. The arrangement of a welding complex has major dimensions.

Problems, solved by the invention, are a gain of complex operation reliability, a diminution of optical channel length. Also are achieved a lowering up to one quantity of rotary mirrors, a protection of welding zone and optical channel from an atmosphere direct action, a lowering of added time and a magnification of complex equipment compactness, a diminution of auxiliary vehicles quantity.

An offered complex has technological laser, optical system, control system. All its equipment allocates inside a pipeline, and technological laser has taking out heat exchanger, in which a pumping of working mixture realizes a pumping mean, arranged on jet engine arbor. And its exterior cooling is carried out with the help of air incident flow. The air flow is organized by drive compressor vanes. Complex power supplying is carried out a generator, which has brushes, interacting with rotated arbor. On laser output window an optic-focusing system with rotating mirror and its rotary drive around of pipeline axis is anchored. The laser and the drive have drive units and complex transposition units along the pipeline, and the drive has brake shoes. An air tightness of laser heat exchanger in arbor input place of the drive is ensured with a unit, which comprises a bearing assembly and vacuum seals.

The complex transposition on tube flat interior surface will provide absence of different kind of optical devices vibrations and will save from periodically spent operation of their alignment.

The given arrangement allows excepting practically all exterior vehicles.

Using of jet engine in complex composition allows solving at once 3 problems:

1. The security of mixed gas pumping in technological laser contour.
2. The security of generator operation, which gives a power supply for all complex.
3. The realization of fast air passage, and by that the cooling of technological laser heat exchanger.

The complex looks like this (fig. 1,2).

On the technological laser 1 optic-focusing system 2 with both rotary mirror 3 and drive unit and rotating mechanism of optic-focusing system around of pipeline axis 4 is anchored. On a nozzle of optical system a data unit of junction detection and control 5 is anchored. The laser heat exchanger 6 is exceeded outside of its bounds. The mixed gas pumping is ensured the pumping mean 7, arranged on the arbor 8 of the drive 9. The air tightness of heat exchanger in arbor input place is ensured with a unit 10, including a bearing assembly and vacuum seals. Behind laser heat exchanger is electric power generator 11 with brushes 12, providing with power supply of the laser and all other complex systems. The power supply moves to the laser through a cable 13. Behind the generator is arranged the air engine 14 of the drive 9. The fuel for engine run is disposed in special cisterns 15. The complex transposition is ensured with drive unit and transposition units 16. They also ensure complex orientation, concerning pipeline axis (figs 2). The complex pull-off during welding ensure brake shoes 17, going out from its housing and resting on tubes interior surface. On a figure 2 brake shoes are shown in stop standing. The control of complex parts is ensured with the control system 18. During welding the optic-focusing system is erected on the junction of the pipeline 19 and welded on it tube 20. The power supply of units 16 at complex transposition along the tube and other systems, for example control system, is ensured with the storage device 21.

The complex operates as follows. With the help of transposition units 16 complex moves on the pipeline19 to tube welding place 20. The junction location is defined with the help of data unit 5, giving conforming signal on complex control system 18. After that the complex stops, the nozzle of optic-focusing system 2 is erected precisely opposite of the junction. By control system command brake shoes are moved out the housing and are erected directly at the pipeline. Further is switched on the drive 9. The drive supply is ensured with fuel, which is taking place in cisterns 15. The running engine ensures the arbor rotating 8. At the arbor rotating with the help of pumping mean 7, arranged on its end, the pumping of working mixture in laser heat exchanger 6 starts. The air tightness of rotated arbor input place in the heat exchanger is ensured by the unit 10, comprising the bearing assembly and vacuum seals. Simultaneously starts electric power output by the generator 11, interaction of the rotated arbor with brushes of the generator 12. The selection of drive operation conditions and electric power distribution between complex systems is ensured with complex control system. The rotated compressor vanes 14 (are hardly bound with drive arbor) ensure high-power air stream, cooling heat exchanger at its operation. The complex control system simultaneously includes the laser and rotation drive 4 of optic-focusing system 2. Thus laser electrical supply is ensured through cable 13. The beam, generated in the laser, is guided on a rotary mirror 3, and being reflected from it, is guided through optic-focusing system to welding place. Simultaneously with process of welding the charging of storage devices 21 is made. After welding process with a circular weld will be completed, on control system commands are switched off the laser, the drive, the brake shoes mount in complex housing and the complex moves to the following junction. The readiness or lack of readiness of the exterior operation - joining of a new tube to the pipeline is ensured with a position sensor behind the junction. After holding the conforming operation, the position sensor applies the signal on the control system and the work cycle is iterated.

 

What is claimed is:

1. A moving complex for continuous welding of pipelines, comprising a technological laser, an optic-focusing system, a control system, characterized in that all complex equipment allocates inside a welded pipeline, and technological laser has taken out heat exchanger with pumping mean, arranged on jet engine arbor, and also optic-focusing system with a rotary mirror, focusing element, data unit of junction definition and a drive of optic-focusing system rotation around of pipeline axis, and jet engine has vanes on an arbor.
2. The complex according to claim 1, wherein the jet engine arbor is the generator rotated arbor.
3. The complex according to claims 1,2, wherein both technological laser and jet engine have drive units and mechanisms of transposition along the pipeline, and jet engine has also brake shoes.
4. A complex according to claims 1,2,3, wherein heat exchanger of technological laser has the unit with vacuum seals and bearing assembly.

 

 

1. Application № 2143649, priority 29.06.83, Great Britain, applicant Fairey Engineering Ltd.
2. Inventor’s certificate № 1158321, B 23 K 11/04, USSR (in russian).