RU2136468C1 - Laser welding set for pipelines - Google Patents

Abstract

FIELD: pipeline laying in steppe, desert, tundra. SUBSTANCE: self-contained power plant, control system, pipes to be laid and welded and welding laser are mounted on platform. End of pipeline is arranged on platform in clamp. Welding head and laser are placed inside pipeline which provides minimum length of optical waveguide and vibratory oscillations of beam relative to welded joint. Welding is carried out from inside of pipe. Supply of power and, when required, cooling water, gases, etc is provided by communication boom. Each socket of magazine is furnished with boom for communications. Mechanism for connection and disconnection of communications with laser and welding head inside pipe is mounted on end of boom. EFFECT: simplified design, enhanced reliability in operation. 3 cl, 3 dwg

Description

 The present invention relates to the field of laser welding and can be used for laying main pipelines for various purposes in the field, especially in the northern regions.

 It is known that laying pipelines in the northern regions requires a high pace, because the construction period is sharply limited, heavy equipment can go through the swampy sections of the tundra route only in winter [1].

 Known welding complex for the manufacture of a continuous pipeline [3]. A distinctive feature of the complex is that all its equipment is located inside the pipeline being welded. The complex includes a technological laser, an optical focusing system with a drive for its rotation, a control system, a fuel supply, an engine, a generator that generates electrical energy necessary for the autonomous operation of this welding complex. A technological laser for welding pipes with a thickness of 10 - 25 mm must have an output radiation power of at least 20 kW and a power consumption of at least 400 kW. Such a welding complex is technically very difficult to implement in the cramped volumes of the pipeline. The complex is controlled autonomously during its movement along the pipeline, as well as during welding.

 The disadvantages of this complex are the design complexity, large dimensions of the complex, as a result of which welding of only large diameter pipes is possible, and the relatively low reliability of the complex as a whole.

 A known installation for laser welding of pipelines [2]. The installation includes a mobile device, a platform with a technological laser placed on it, control equipment, a power plant, and auxiliary equipment. It also includes a beam line store with pipes designed for welding located on them and a device for clamping the pipe to the pipeline.

 Installation works as follows. A store with beam lines and pipes intended for welding using its own drive brings the end of one pipe to the end of the pipeline fixed in the clamps. Using the preload device, the pipe is pressed to the end of the pipeline. After that, the laser is turned on and the radiation through the beam line is fed to the rotary mirror. Then it is fed to the focusing lens and then to the welded joint. After welding the annular seam, the installation moves forward along the pipeline route at a distance equal to the length of the pipe. The beam path store supplies a new pipe with its beam path to the weld zone and the process cycle repeats.

The disadvantages of the design of the above installation are:
a large length of the optical path, which leads to distortion of the wavefront and the difficulty of accurately directing radiation to the welding joint due to vibrations of the beam path and the welding head mechanically associated with it;
the complex and expensive design of the store, which has a separate beam path in each socket, at the end of which a focusing lens and a swivel mirror are fixed.

 The problem solved by the invention is to increase the reliability of the installation design by simplifying its design and improving the quality of the weld by reducing vibration of the optical elements of the complex.

 The above problem is solved in that in the installation for laser welding of pipelines, which includes a mobile device, a platform with a technological laser placed on it, control equipment, a power station, auxiliary equipment, a shop with pipes for welding, a device for pressing the pipe to the pipe (welding head and technological the laser is inside the pipeline). The installation has communication supply rods, and each rod has a mechanism for connecting and disconnecting from the welding head.

 The technological laser is in a single design with a welding head.

 The welding head has wheels in contact with the inner surface of the pipeline.

 The welding head has a battery, an engine, and displacement actuators inside the pipeline.

 The communications supply bar has electrical, pneumatic and hydraulic communications.

 The installation is as follows (Fig. 1). The mobile device 1 moves the platform 2 along a previously prepared track. On the platform are the control system for installation 3, an autonomous power station 4, a power source and auxiliary systems for the technological laser 5. The store 6 with tubes 7 located in its sockets has its own rotation drive 8 (Fig. 2). The store also has a mechanism for pressing the pipe to the pipeline 9 and a supply bar 10. Each socket of the store has a communication connection unit 11. In the case where not the entire technological laser is in the same design with the welding head, but only its emitter, the pumping unit for the working mixture 12 and a laser 5 power supply are located on the platform. The platform also has auxiliary processing equipment 13 (shielding gas cylinders, gas treatment devices, etc.).

 Each rod for supplying communications has a mechanism for connecting and disconnecting with the welding head 14 (Fig. 3). The welding head includes a focusing lens 15, a rotary mirror 16, a drive for their rotation 17 around the axis of the pipe 18. The welding head may also include a technological laser 19 without a power source and a working mixture unit. To move along the inner surface of the pipeline, the welding head has a battery, an engine with actuators 20 or wheels 20. The focusing lens has a sensor for determining the position of the joint 21 and a drive for longitudinal movement 22. The end of the pipeline is placed on the clamps 23 mounted on the platform.

 Installation works as follows. Shop 6 with rods for supplying communications 10 brings one of the pipes 7 to be welded to the pipeline 18 and centers them. The end of the pipeline is fixed in the clamps 23. Using the device (mechanism) clamp 9 is the joining of the ends of the pipe and pipeline.

 Using the sensor for determining the position of the joint 21 and the drive of the longitudinal movement 22, the focusing lens 15 of the welding head is mounted exactly opposite the joint. Then, at the command of the control system 3, the technological laser 19 is switched on (Fig. 2) and the radiation is supplied to the rotary mirror 16, from which it is directed through the focusing lens to the welded joint. The rotation drive 17 provides welding of the annular seam. All the necessary signals from the control system, cooling to the lens nozzle, shielding gas from auxiliary technological equipment 13 are carried out by the rod 10. As an option, the pumping unit for the working mixture of gas and the power source 12 of the laser can be removed, i.e., split the laser into two parts . One part, in fact, the emitter, is always inside the pipe, and the other, more dimensional, power source, auxiliary gas and water treatment systems are on the platform. The connection between them is carried out by a supply bar. The power supply of the complex is provided by the power station 4. If the welding head has a battery with a drive and actuators 20, then after welding of the annular seam, by the command of the control system, the mechanism 14 is disconnected, and the installation, using the mobile device 1, moves along the pipeline route by the length of the pipe. Store using drive 8 feeds a new pipe and centers it with the end of the pipeline. The welding head using the actuator 20 moves along the inner surface of the pipeline to the junction. The exact installation of the focusing lens relative to the joint is carried out by the sensor 21 and the drive 22. The mechanism 14 connects the rod 10 with the welding head. During the operation of the store, switching the supplied communications from one socket to another is carried out using the node 11.

 If the welding head does not have its own drive, but only the wheels, while moving the installation to the length of one pipe, the mechanism 14 does not disconnect the rod 10 and the welding head. Disconnection is made only before the operation of the store, carrying out the operation of feeding a new pipe, i.e. each time, the rod pulls the welding head to a new welding location.

 Compared to the analogue, the power supply of the main elements is carried out, which makes it reliable. The dimensions of the installation are significantly reduced, its design is simplified. Compared with the prototype, the installation has only one welding head with a swivel mirror, a focusing lens, a sensor for determining the position of the joint, rotation and longitudinal drives, and not a lot - by the number of sockets in the store, the optical path length of the beam is significantly reduced, since it is formed in laser head in the immediate vicinity of the joint being welded.

 The use of such a design of the installation will make it as simple as possible, increase the reliability of its operation and increase the quality of welds in the pipeline.

List of references
1. O.M. Serafin, A.P. Ladyzhansky, M.V. Blekherov "How to cook a short rotation?", "Potential", N 1, 1998 "p. 42.

 2. "Installation for laser welding of pipelines", Russian patent N 2074798 B 23 K 26/06. Priority dated 08.16.94, published on 03.10.97, Bulletin No. 7.

 3. "Welding complex for the manufacture of a continuous pipeline", Russian patent N 2074799, B 23 K 26/06. Priority dated August 29, 94, published March 10, 1997 Bulletin No. 7.

Claims (3)

 1. Installation for laser welding of pipelines, comprising a mobile device, a platform with a power station, a control system, a store with pipes placed in its sockets and intended for welding, with its drive and a device for pressing the pipe to the pipeline, a welding head and a powerful laser, including an emitter, a power source and auxiliary systems, characterized in that the welding head, laser, or at least the laser emitter are mechanically connected to each other and are arranged to be placed inside the pipe oestrus, and each slot is provided with the rod magazine communication with inlet disposed at its end of the connection and separation mechanism communications with a laser and a welding head inside the welded tube.  2. Installation according to claim 1, characterized in that the welding head is equipped with wheels for contacting with the inner surface of the pipeline.  3. Installation according to claim 1 or 2, characterized in that the welding head is equipped with a battery, drive and actuators for movement inside the pipeline.

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