Description :: Our patents

The guessed invention falls into fields of materials treating with the help of beam techniques and can be used for laser welding of different assignment pipelines in field requirements (desert, tundra, steppe etc.), for example, oil pipelines, gas conduits and etc. The invention can be used also for pipelines constructing of other assignments, for example, heat lines.

Known installation for laser welding of tubes circular welds [1] includes moving optical system for laser radiation delivery from a source (technological laser) in a welding zone. The moving optical system includes four water-cooled mirrors: three reflecting and one focusing, jointing among themselves with a beam guide.

The installation operates as follows. The laser beam from technological laser is guided on the first mirror, being reflected from which is guided through the beam guide on the second mirror. The second mirror -moving, is arranged on a carrier, which one in turn has an opportunity during process of welding to move around of a welded tube on half of its perimeter (180⁰). Being reflected from the second mirror, the beam falls on the third mirror, arranged on an annular-shaped chariot, such as a cramp, displaced orbital around of a tube on 360⁰. Being reflected from the third mirror, the beam is guided on a last focusing mirror, being focused, is guided immediately to a welding zone.

The above-stated installation has following disadvantages:

1. A beam channel has on the extent some water-cooled mirrors. This carries on to wave front distortion, to state transition of radiation polarization during welding process, and, therefore, to a variability of radiation properties on a trajectory of its motion, that in turn carries on to a variability of welded joint quality on its extent.

2. On each of four mirrors the particular quantity of a radiated power is absorbed and consequently for embodying of laser welding process needs electric power added lead and also composite system of their water cooling.

3. During passing around of a tube (360⁰) mirrors should have changed angular standings rather one another, permitting to provide precise transporting of radiation from a source to a junction place. It demands availability in system of radiation transporting mechanisms and drive units, providing angular travel of mirrors, and also monitoring system of their angular standings.

4. The precise joining of tube ends is necessary for embodying process of tubes welding with a circular weld in practice. The given operation is laborious and is specially complicated at welding tubes of major diameters in field requirements. In viewed installation this problem is solved at the expense of usage of other mechanisms, irrelevant with the installation. Thus for realization of qualitative holding of welding process (a maintaining of constant distance from focusing device up to welded surfaces on all perimeter, a control of focussed radiation axis leaving from the junction) is necessary to solve an added problem. There are precise relative position of mechanisms, which joint ends of welded tubes, and system of radiation transporting from a source to welding place.

Welding complex for manufacture of continuous pipeline loses above-stated disadvantages [2]. The complex incorporates intratube welding machine 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 welding complex operates as follows. The tubes, intended for welding, are erected in clamps, arranged on an uniform platform with clamps of pipeline end. An added installation of their ends it is not required. This most eliminates the fourth disadvantage of the previous analog. After that, using self drive unit, intratube welding machine goes in welded tube bore, moves inside it on all length up to a place of the junction with the pipeline. The welding of a circular weld is further yielded, after an ending of which intratube welding machine moves back inside welded to the pipeline tube to an exit. Exiting from a tube, it moves in the container. Further welding complex moves forwards on length of a tube. After that on a platform following tube charging, its joining and centering concerning the pipeline is yielded. Intratube welding machine is inlet into a bore of an again welded tube and a work cycle is iterated.

In complex composition is not entered the composite system of radiation transporting, including beam guides, some water-cooled mirrors, mechanisms and drive units of their transposition and space orientation, monitoring system of mirrors orientation rather one another during execution of a trajectory, providing execution of circular welding. Therefore, the first three disadvantages of the previous analog are excepted.

However given complex has following disadvantages:

For embodying of pipeline welding process in field requirements without composite optical system it is necessary to use an arc technique of welding instead of laser. This in practice carries on to sharp aggravation of operating performances of a weld and, accordingly, to lowering reliability of pipeline operation, being important parameter, since the emergencies of pipelines carry on to the extremely important expenditures on elimination of their consequences.
Low efficiency, connecting with a major part of added time. For realization of one complete work cycle, intratube welding machine should doubly pass inside a welded tube on all its length, that demands expenditures of time. Thus all welding complex stands, as following operations holding - charging and centering of a new tube at complex given construction is impossible. Besides process of welding machine transposition inside a tube on all its length, its input and output in a tube hole, its transposition in the container and return extraction from it is always bound to foregone vibrations, possible shocks etc. That has an effect for operation reliability of a complex as a whole.

The installation for laser welding of pipelines is known [3]. There is our prototype. The installation includes a moving mean, platform, on which technological laser, clamps for centering a pipeline and welded tube, box of beam guides, which look like tubes are disposed. On ends of beam guides are anchored focusing devices with a drive of rotation around of an incident radiation axis and with wheels, anchored on their exterior. Besides the box has a device of a tube contraction to a pipeline, drive unit of transposition or rotating of the box, mechanism of a focusing system transposition along beam guide axis.

The laser beam, generated by technological laser, through a beam guide is guided to a junction place, where by a rotary mirror is guided to a focusing device, then falls on welded junction. With the help of focusing device rotation drive the welding of a circular weld is ensured. A new tube charging on free after the previous process of welding beam guide at this time is carried out.

The given installation allows realizing a laser technique of welding, that rises sharply use reliability of the pipeline. At considerable simplification of radiation transporting system - the quantity of mirrors is reduced from four up to one, mechanisms and drive units of their transposition in space and mutual angular orientation are absent, the system of mirrors water cooling is simplified.

The application of the given installation allows reducing an added time of a work cycle. Since is excepted the traveling time of intratube welding machine from the container from a tube beginning up to the welded junction and back. And also the time of welding process with a loading time of a new tube is combined. All this essentially rises operation productivity of given installation in comparison with analog.

The installation has following disadvantages:

Necessity of radiation transporting on major distances (it is from above 10 meters) from a stimulus source up to welding spot, that aggravates quality of radiation - distortion of a wave front, divergence of radiation, and also carries on to a leaving of radiation axis from indispensable. That can be caused by vibrations of operating mechanisms, and also inexactness of operating mechanisms of radiation transporting system. The above-stated disadvantage carries on to dynamic variations of focussed beam location on tubes handled places, to its leaving from an axis of welded junction trajectory and, therefore, to flaws of a weld, that in turn carries on to lowering use reliability of the pipeline.
Bulk of installation.

It is known, that for welding thickness from several mm up to several cm, used for long distance pipelines [4], are demanded radiated powers ten and more kilowatts. The radiation of such power is usually received with the help of fast flow lasers with longitudinal and cross pumping, or multichannel wave guide lasers with diffusion refrigeration, or solid lasers.

It is known also, that functionally a laser is possible to divide into radiation oscillation block, power supply, a system of a pumping and cooling (fast flow lasers) and added systems [5].

Problems, solved by the invention, are an improvement of a weld quality and, therefore, pinch of use reliability of pipelines, and also pinch of complex compactness.

The above-stated problems are solved by that in offered complex, incorporating a moving mean, a platform, with clamps and added equipment, disposed on it, technological laser, both power supply and other added systems, which are taking place on a moving mean. The laser is fulfilled as pluralities of disposed in a box oscillation blocks with overall dimensions on length less welded tube, and on breadth and height less its diameter, with focusing systems, anchored on their ends. And technological process is carried out at the expense of a team working of laser power supply in aggregate with a package of added equipment and oscillation block, built-in in a given moment in a technological chain. The box of oscillation blocks can be replaceable and has constant connection with power supply and added equipment in the form of cables or to have a quick-release unit. This unit permits promptly to dock and to disjoin indispensable for operation of oscillation blocks communications (service lines): electric power, process gases, water or oil cooling, signals of control system and etc. In the case of constant connection the box of oscillation blocks in avoidance of cables tangling, if it is fulfilled as a drum, operates in a reversible mode, and, if it is fulfilled with a linear arrangement of oscillation blocks, - in a reciprocation mode. The blocks of oscillation have mechanisms of rotating concerning an axis of generated radiation. The complex added equipment includes a tracking system of focussed radiation axis at welded junction, including fastened on interior surface of welded tube easily detachable fixing ring and also being exposed to it, hardly fastened with a focusing system roller. The arrangement of oscillation blocks inside welded tubes allows maximum to approximate generated by them radiation immediately to welding zone, i.e. to reduce maximum a distance of its transporting. Thereby are eliminated disadvantages of the prototype, bound with a quality of radiation, going to a focusing system, a location precision of focussed radiation and, therefore, are reaches the greatest possible quality of a welded joint.

The realization of oscillation blocks rotating inside a welded tube around of generated radiation axis allows to support a vector of radiation polarization in relation to welded surfaces stationary during all welding process, that ensures persistence of service properties of a weld on all perimeter.

Arrangement of one of technological laser devices - oscillation block, having major dimensions, immediately in a box (dimensions of the box do not vary as contrasted with the prototype), and power supply with added systems and power station on a moving mean allows essentially to reduce dimensions of all complex. The availability of the tracking system of focussed radiation axis at the welded junction allows simply and trusty to check an optimum standing of a focusing system.

Embodying of an offered complex is maximum effective at using of technological lasers, having drawn radiation oscillation blocks – fast flow lasers with a longitudinal pumping, multichannel waveguide lasers with diffusion refrigeration, solid lasers. That allows using their radiation excellence, for example, as contrasted to fast flow lasers with a cross pumping, simultaneously with diminution of dimensions of all complex. Fast flow lasers with a longitudinal pumping allow to implement an offered complex construction, but have essential restrictions by opportunities, and, therefore, on a radiated power. Because apart from blocks of oscillation for their operation are necessary composite systems of pumping and refrigeration, structurally bound with them, and also availability in immediate proximity pumping means, that increments dimensions of oscillation blocks and by that reduces technological opportunities of all complex.

The solid lasers also can be used in an offered complex, however they have limitations of radiation power and, accordingly, of complex technological opportunities. Besides the block of refrigeration of these lasers should be also in immediate proximity with an active element.

Most preferable in an offered complex is usage of multichannel waveguide lasers with diffusion refrigeration, for example [6], having a high level of energy and angular stability, design simplicity, absence of interior vibrations (see page 115 [5]). It allows achieving high quality of welded joint. Besides, design features of multichannel waveguide lasers with diffusion refrigeration are distinguished with availability of active medium of major extent and minor cross sectional dimensions, that matchs to the shape of tube interior space. As the complex construction defines discrete operation of each of oscillation blocks, i.e when used one of them other does not operate, the cooling system of each of them can be simplified and have small dimensions.

The availability of easily detachable coupling allows to disconnect operatively communications (service lines) of oscillation block, which is taking place in already welded tube, from the power supply and other systems. And after leading up with a box to a new tube with a new oscillation block in welding standing (building in a technological chain) to joint communications (service lines) from the power supply and other systems to this oscillation block.

As the operational mode of oscillation blocks is sequential, for security of all complex operation one power supply, and also one set of added equipment is sufficient. Each oscillation block has the mechanism of rotating around of generated radiation axis inside a welded tube. This mechanism realizes also precise centering of oscillation blocks concerning a tube.

The installation looks like this (figs. 1, 2, 3). On a platform 1 in clamps 2 the end of welded pipeline 3 is erected. In a central part of a platform a box 4 of oscillation blocks 5 is arranged. Power supply and laser added systems 6, and also power station 7 are on a moving mean 8. To oscillation blocks ends (figs. 2) with an output window 9 are mounted focusing devices 10 with rotary mirrors 11 and hardly fastened with them rollers 12, mechanisms of focusing system transposition along axis of generated radiation 13. On an exterior of oscillation blocks the mechanism of rotating 14 is disposed. On oscillation blocks intended for welding tubes 15 are disposed. The oscillation blocks security with necessary process gases, cooling liquids, electric power, and also the delivery of command signals are carried out with the help of stationary cables, or with the help of quick disconnect coupling 16, joined by means of a cable 17 with power supply and other systems of technological laser (fig. 3). The complex has common control system 18. Besides the complex is supplied with a unit of welded tube contraction to the pipeline, and also with box transposition (rotation) drive (on figs. are not shown). The tracking system of focussed radiation axis at welded junction includes apart from rollers 12 also fastened on an interior surface of the welded tube quick detachable fixing ring 19.

The complex operates as follows. The box 4 of oscillation blocks 5 and intended for a welding tubes 15, arranged on them, leads up one tube end to pipeline end 3, anchored in clamps 2. The centering of oscillation block is carried out with the help of arranged on an exterior wheels with mechanisms of rotating of oscillation block 14, which are in touch with an interior surface of welded tube and mutual centered with clamps 2. The tube contraction unit (is not shown) contracts a tube to a pipeline end. A mutual centering of a pipeline and welded tube realizes with the help of quick disconnect coupling 16. The connection with power supply and other systems of technological laser 6 is carried out with a cable 17. Further with a command of control system 18 the laser radiation oscillation is ensured. The laser beam through an input window 9 falls on a reflecting mirror 11, being reflected from which it is focused in a focusing device 10 and is further guided immediately to a welding zone. The rotating of oscillation block with a focusing device together with a rotary mirror ensure a technological process of a circular weld. Thus a roller 12, hardly fastened with a focusing device, rolls around a quick-detachable fixing ring 19, which one is previously erected so, that its lateral area is hardly verified in relation to a welded tube end (distance X on fig. 2). Simultaneously with welding process is yielded a charging of a following tube on oscillation block, free after previous welding process. Thus on an interior surface of this tube erects a quick-detachable ring 19 with verified and hardly fixed distance X from its lateral area up to a welded tube end. The welding process of a single circular weld is essentially time limited. So using of multichannel waveguide lasers with diffusion refrigeration it is possible to use simplified coolant system of the oscillation block or generally to do without it, that carries on to simplification of complex construction, and also to further diminution of its dimensions. At the same time major length of welded tubes allows rather easily during some passes of discharge tubes to accumulate for execution of technological process necessary welding power. Thus enough overall oscillation blocks will be wholly arranged inside tubes, intended for a welding, i.e. to allocate inside a box and by that to make a complex more compact (first of all in length), that is actual in field requirements.

All processing equipment, except power supply with added systems 6, power station 7, providing complex electrical power supply, and also control system 18, allocates on a uniform platform 1.

After a tube welding to a pipeline, and also a new tube charging in a box, the complex with the help of a moving mean 8 moves forwards on a tube length. The mechanism of focusing system transposition along axis of generated radiation 13 with a rotary mirror moves a focusing system closer to an output window of oscillation block of on distance, providing unobstructed operation of a box. After that the box gives to a welding zone following oscillation block with a new tube. Thus automatically or with control system command there is a separation of communications (service lines) with oscillation block, just now realized a tube welding, and a connection them to oscillation block, which one will realize following tube welding. Taking place in contact to it by means of wheels 14 the tube at this moment is docked to the pipeline (is built into a technological chain). The mechanism 13 returns a focusing system in a home position and the work cycle is iterated.

The construction of a box with oscillation blocks, arranged in it, and tubes, intended for welding, taking place in contact with blocks, can be structurally variously executed - with a linear arrangement of oscillation blocks, with a rotor type with a horizontal rotating axis (see fig. 1). And on problems, solved with the invention, does not influence.

If the connection of blocks is carried out not with the help of a quick disconnect coupling, but with stationary cables, the mechanism of oscillation blocks box operation will be following: at first are an operation of all oscillation blocks from the first up to the latter. Further, in a reversible mode, - after operation of the last oscillation block starts to operate last but one etc. up to first, then operation cycle is iterated.

For more comfortable installation of new tubes in a box of oscillation blocks, and also installation of easily detachable fixing rings in them the application of replaceable boxes is possible. Thus the complex operation will be carried out sequentially with replacement of boxes, worked out on a complex, by new, "charged" with tubes, intended for a welding in stationary conditions.

Thus in offered complex construction a distance of radiation transporting from an output window of oscillation block up to welding spot is done minimum possible, that minimizes negative influences of variations of radiation properties, and also allows to guide the focussed radiation on the welded junction more precisely. By this are excepted weld flaws, is improved welding quality and jointing reliability.

The arrangement of one functional systems of technological laser, namely block of oscillation, inside a box construction, not changing its dimensions, and power supply with added systems, power station, control system on a moving mean allows to increase essentially all complex compactness. That essentially will have an effect on its maneuverability.

What is claimed is:

A laser complex for pipeline constructing, comprising a moving mean, a platform, a technological laser, a control system, a box with tubes, added equipment, characterized in that the technological laser has arranged inside each box tube blocks of oscillation with length overall dimensions less than welded tube and with diameter less than welded tube diameter, with focusing systems and reflecting mirrors, disposed on their ends, and with focussed radiation rotating mechanism around of tube axis.
The laser complex for pipeline constructing according to claim 1, wherein oscillation blocks with rotary mirrors, anchored on them, and focusing devices have self rotation drive around of a tube axis.
The laser complex for pipeline constructing according to claim 1, wherein each focusing device has self - rotation mechanism around a tube axis, and oscillation blocks are immobile during welding.
The laser complex for pipeline constructing according to claims 1,2, wherein the added equipment have the tracking system of focused radiation axis at welded junction, including fastened on interior surface of welded tube easily detachable ring, and also the roller, taking place in contact with it and hardly fastened with a focusing system.
The laser complex for pipeline constructing according to claims 1, 2, 3, 4, wherein the box of oscillation blocks is fulfilled replaceable.