SU1574310A1 - Method and apparatus for producing helical welded tubes - Google Patents

Abstract

The invention relates to the production of spiral seam pipes by the method of high-frequency welding, in particular, to a method for producing spiral-seam pipes and a device for its implementation. The purpose of the invention is to improve the quality and productivity of pipes. When used as a blank strip with unstable geometric and strength parameters, the formed blank 17 in the welding zone is held by adjustable rollers 5, 6, 12 and 13. The rollers 5 and 13 set the required outer diameter of the pipe, and the rollers 6 and 12 moved by the drive 9 are burst pipe in internal diameter force F _rasp. , F _rasp. ≥K ^. [Σ] _izg. ^{. B.} H ² / 1.81 ^. R _p , where K = (1.2 ... 1.5) is the proportionality coefficient, taking into account the oscillation of the parameters of the original band

[σ] _izg. - admissible bending stress of the strip, kg / mm ² , B - width of the strip, mm

H - strip thickness, mm

R _p = R _tr - H / 2 - the estimated radius of the pipe, mm

R _Tr - outer radius of the pipe, mm. Stabilization of the molding and welding processes by optimizing the geometry of the workpiece in the welding zone improves the quality of pipes produced from the strip with deviations of geometric and strength properties. 2 sec. and 3 z. p. f-ly, 3 ill.

Description

The invention relates to the production of pipes and can most effectively be used in high-frequency welding of spiral-seam pipes.

The aim of the invention is to improve the quality and productivity of pipes.

In the process of manufacturing pipes to maintain the conditions of molding and welding when the deviation of the geometric dimensions and elastic properties of the original strip to the inner surface of the pipe along the diametral line passing through the welding point, constantly create a force arching the pipe, which ensures a stable position of the molded tubular billet reducing the diameter of the pipe, increasing the edges in the weld, and also maintains the degree of filling of the cavity of the molding sleeve by the strip, thereby stabilizing resistance strips forming process billets and eventually by reducing the forced stopping process improved quality of the pipe and seen to rise process performance.

The proposed device allows a more rigid connection of the forming device with both the strip and the finished pipe during high-frequency welding of pipes and thereby reduce fluctuations in the molding parameters when the deviation of the geometric dimensions and elastic properties of the strip. This is possible because the expansion roller, kinematically connected through an elastic element to the inner edge-reducing roller, prevents the pipe from shrinking, and the adjustable support roller, which rotates around the corner of the molding, accepts an arching force, allows you to adjust the degree of filling with the cavity band of the molding sleeve and practically allows you to eliminate the harmful effect on the formation of the arching force. In addition, the proposed design of the device allows the console to be unloaded, on which the internal edge-clamping roller and rammer are mounted.

Such a constructive embodiment of the device allows improving the quality of the pipes when they are manufactured from a strip with non-constant geometrical dimensions and elastic properties.

Fig, 1 shows a diagram of the device for implementing the method; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a section BB in FIG. A device for manufacturing spiral-seam pipes contains a setting machine 1 and a molding sleeve 2, between which wiring 32 is installed. To heat the edges of the strip to the welding temperature, use a VFS 4.1 welding device. Edge rollers 5 and 6 are located in the welding zone. 5 is provided with a screw mechanism 7 of radial movement, and the inner edge-clamping roller b is rigidly connected to the plunger 8 of the hydraulic cylinder 9 fixed on the console 10. The hydraulic cylinder 9 is equipped with a second plunger 11, at the end of which is fixed A spacer roller 12 is located. A support roller 13 is mounted under the spacer roller 12 on the molding sleeve 2 with the possibility of radial movement of the wedge 14 from the screw mechanism 15. The rollers 5, 6, 12 and 13 are placed on the diameter line Oi-0i passing through the welding point C and unfold the corner molding a.

The drawings also show strip 16, pipe billet 17, pipe 18, and rammer 19.

The method is carried out as follows.

The strip 16 of the master machine 1 through the wiring 3 is fed into the molding sleeve 2, where the tubular billet 17 is molded from it. The adjacent edges of the strip 16 are heated

welding device A and weld together, holding them in the desired position by the edge-clamping rollers 5 and 6,

Regulation of outdoor position

the hemming roller 5, in height, largely defining the diameter of the pipe 18 to be manufactured, is produced by a screw mechanism 7.

In the process of manufacturing pipes along the diametrically Oi-Oi line passing through the welding point C, an arching force Fpacn. Is applied to the pipe 18 and the pipe billet 17 created by the hydraulic cylinder 9 when the internal edge-clamping

the roller 6 and the spacer roller 12. This method prevents the diameter of the pipe being manufactured from decreasing, and the outer edge-pressing roller 5 and the supporting roller1, 12 with the molding sleeve 2 limit the increase in the pipe diameter,

8to avoid possible overshoot in the weld seam and decrease the pipe diameter when changing the parameters of the original strip (its thickness, elastic properties

and others), arching force Fpacn. create, taking into account the rigidity of the formed billet, providing guaranteed compression of the welded edges to the outer edge-pressing rollers 5 s

on one side and pressing the spacer roller 12 with the strip 16 formed into the tube blank 17 against the support roller 13 on the other side.

Required amount of arching

effort Fpacn. determined by the following formula:

split

TO

Nizh.-b-h2 1,81 -Rp

0

five

where K (1.2-1.5) is the proportionality coefficient taking into account the variations in the parameters of the original band;

about izg. permissible bending stress of the strip, kg / mm;

B is the strip width, mm;

l - strip thickness, mm;

RT RTP - h / 2 - the estimated radius of the pipe, mm;

RTp - outer radius of the pipe, mm.

Example. In the manufacture of spiral-seam pipes with a diameter of 325 mm from a strip width of 500 mm and a thickness of 4.0 mm and with

the allowable voltage of the pipe is 15 kg / mm2

Rrasch. 1,5-fs

15-500-42

1.81-160.5

 622 kg

In such a process, in the case of a change in the elastic properties of the strip formed into the pipe billet or when the strip thickness increases, the diameter of the pipe to be manufactured is obstructed by the force that tears the pipe along the internal diameter applied along the diametral lines passing through the welding point C, due to which the pipe retained by internal edge-clamping rollers in the upper position and did not move away from the working cavity of the molding sleeve, which allowed maintaining its filling degree and stabilizing the diameter pipes and the position of the edges in the weld zone.

The use of the invention allows to improve the quality of the pipes and to increase the productivity of the process of manufacturing the pipes from a strip with non-constant geometric and strength parameters due to the stabilization of the processes of molding and welding. In addition, when using the device, the implementation of the method allows to unload the console, on which the internal edge-clamping roller and reamer are mounted, which is very important for reducing the elastic deformation of the console and for qualitative removal of internal burrs. This is made possible by the fact that the force that bends the pipe locks directly on the pipe, the supporting and outer edge-clamping rollers.

Claims (5)

1. A method for manufacturing spiral seam tubes in which a strip is molded 0 g pipe billet, adjacent edges are heated by high-frequency currents; m are welded together by applying a force that bristles the pipe at an internal diameter, characterized in that, in order to improve the quality of the pipes and increase the productivity of the process, the force that cuts the pipe is applied along the diametral line passing through the welding point. 2. Method pop. . This means that the force extending the tube sets at least the force required to maintain the required pipe diameter, and the deformation on the outside of the pipe is limited to a given size. 3. A device for the manufacture of spiral-seam pipes, containing a setting machine / (well, a molding sleeve, a welding device, s, also external and internal crimping rollers for the heated edges of the workpiece, which are what. In order to improve the quality of the pipes and increase the productivity of the process, the device is equipped with an elastic element and a spacer roller installed diametrically opposite to the inner edge-clamping, the axes of rotation of which are connected by an elastic element. 4. The device according to any one of claims 3, 3, and that with the fact that under the spreading roller in the forming sleeve an adjustable support roller is installed. 5. The device according to claim 3, that is, with the fact that the elastic element is made in as plunger hydraulic cylinders with a common working cavity. four FIG. A- A ///// ///// f //////// /// // // // // / / f / -I0 5 Fig1 6 ten / ШШШШЩЩ ЩШШШШ Ш% 0 / I g 13 iii 15 Fig.Z -I0 5 Fig1 6 eight eleven