DE1072578B - Device for the continuous production of longitudinally welded tubes from metal strip - Google Patents

Description

GERMAN

The invention relates to a device for the continuous production of tubes from metal strip, which is heated in a continuous furnace and then shaped into a tube, the longitudinal edges of the Tape are welded together.

It is known to manufacture a tube by passing the heated strip through a forming mill by rounding it to a tubular shape. According to known proposals, the edges of the Flat strip is heated in a continuous furnace before it goes into the forming mill and the welding device get, electroinductively heated to welding temperature. With such an electroinductive If the edges of the belt are heated, good belt guidance is of great importance. The invention The aim is good guidance of the strip in the area of the electroinductive heating of the strip edges.

According to the invention, the guide of the tape in the area of the Auffaeizeinrichtung consists of parallel Rollers mounted on the belt width, of which at least those of the heating device are arranged upstream give the band a flat bulge. To achieve the lateral guidance and curvature is preferred the length of the one convexly curved roller of this roller pair is smaller than the belt width, while the concave counter roll is provided with side flanges, the distance between which is slightly smaller than that Width of the flat belt.

Preferably, three guides are provided behind one another with substantially the same curvature, which is an electric work coil between the two first guides are brought by the edges to a temperature which is about 100 to 200 ⁰ C under Schweißtemperatuir, while the last between the two Guides an electrical heating inductor is through which the strip edges are heated to a temperature that is above the temperature of the liquid scale. The. The arrangement is advantageously made so that top rollers can be lifted up, for example folded down, together with the heating inductors located in front of and behind them. The lower rollers of the guides can advantageously be lowered downwards. Of course, the entire guide device including the heating inductors can also be jointly adjustable in height.

The advantages of the invention can be seen from the following explanation of its details.

The drawing illustrates an embodiment of the invention. It shows

1 schematically shows a side view of the entire device,

2 shows a pair of guide rollers,

3 shows a pair of welding rollers,

Device for continuous

Manufacture of longitudinally welded pipes

made of metal tape

Applicant:

Phoenix-Rheinrohr Aktiengesellschaft
United iron and pipe works,

Dusseldorf

Dr.-Ing, Heinrich Hofmeier, Breitscheid about Ratingen,

Wilhelm Schmidt, Dinslaken (Ndrh.),

and Dr.-Ing. Dr. Erich Hörmann, Düsseldorf-Eller,

have been named as inventors

4 shows the device at the level of the guide rollers.

A steel strip 1, which is unwound from a reel 2, runs in the direction of arrow A through a continuous furnace 3 and, after leaving a door 4 of the thermosetting furnace, enters the working gap of guide rollers 5 and 6. The continuing strip then runs through a further pair of guide rollers 7, 8 via a guide roller 9 into the actual welding mill, which consists of a pair of forming rollers K), 11 and a pair of welding rollers J ^ jJLS. The strip, which is formed and welded into a tube by this welding roller mill, then runs in a known manner through an inductor coil 14 for reheating and from there in a known manner into a reducing roller mill 15.

The shape of the guide rollers 5, 6 is shown in FIG. The band 1 lies between the curved ones Surfaces of the rollers 5, 6 in such a way that it is easily bent and through the flanges 5 α of the roller 5 is held at the side. By bending the tape 1 is stiffened so that it is between the individual successive rollers of the device does not sag. It also prevents this type of leadership the otherwise unavoidable and annoying lateral running of the tape, especially the periodic one Swarming the band in a sideways direction. Therefore, with such a tape guide, the inducing Head of electrical inductors in much larger

so arrange them close to the strip edges and thereby increase both the efficiency of the inductive heating as well as the inductively heated zone. The reduction in size by induction heated zone not only has the advantage of being larger

909 708/102

Claims (4)

Economics of the Äufheizverf ahrens, but in particular the advantage that the band parts outside the narrow Kainrenzon-en remain at such a low temperature that they have a considerable strength and therefore not move in an undesirable manner when welding; the pressure of the welding rollers is therefore mainly used only to press the edges to be welded together. Between the upper rollers 5 'and 7 there is an electric electric induction motor; This inductor consists essentially of two inductive conductors arranged parallel to the strip edges and a transformer through which. the applied voltage is decreased; Capacitors arranged directly behind it are used to compensate for the reactive current. '',. The current supplied has a frequency which is above the usual mains frequency and preferably in the order of magnitude of a few 1000 Hz. As a rule, a range is selected whose electrical penetration depth is greater than or at least equal to the thickness of the strip This ensures a favorable electrical efficiency. Immediately behind the guide roller 7 is a similar heating inductor 17. The rollers 5 and 7 are fastened together with the heating inductors 16 and 17 to a carrier 18 which can be opened up about an axis parallel to the transport direction of the tape. If the part 18 is opened up, the tape is The rollers 6 and 8 are also attached to a common carrier 19. The strip 1 is heated in the furnace 3 to a temperature which is suitable for reducing the stretching of pipes increased by the inductor 16 to a temperature which is about 100> to 200? which is above that of the liquid scale; that is a temperature of about 1380 ° G for steel. ■: ■■ '-:. · ..-.' -.:.;.; .. 'The carrier 19 can be lowered down, so that after 'unfolding the carrier 18 and Lowering of the carrier 19, the belt runs completely free. The supports 18 and 19 can also be jointly adjustable in terms of their height. The guide roller 9 is attached to a lever 20 which can be pivoted about a pivot point 21 so that the roller 9 can be folded down in the direction of arrow B during operation. ... Fig. 4 shows a cross-section through the device at the level of the guide rollers 5 and 6. The carrier IS can be opened in the direction of arrow C about an axis 18a, which is parallel to the belt axis. It is also height-adjustable in the direction of arrow D. ' The carrier 19 is adjustable in height in the direction of the arrow E. The following does not belong to the invention: Behind the roller 9, the band is bent into a tube by the forming rollers 10 and 11 (FIG. 3), the two edges la and Ib of the band i, heated by the inductors, being at the bottom. The longitudinal edges 1 α and Xh are pressed against one another by the welding rollers 12 and 13 arranged directly behind them in such a way that they weld to one another. The roller 13 has in her. In the middle a groove 13a into which the weld bead can enter. The welding bead is removed by a cutting tool 22 in a known manner. The inductor coil 14 heats the tube, which despite the inductive heating of its edges, has assumed a temperature which is generally lower than the temperature of the furnace 3, to the temperature which is suitable for the stretch reduction. In doing so, the temperature of the pipe is also equalized over its entire circumference. To achieve such a balance, it is advisable not to arrange the inductor coil concentrically. The guide rollers can, for example, also be arranged in such a way that the pipe is provided with a weld seam lying above. The door 4 at the exit of the oven 3 or a side guide can serve to align the incoming strip. The Aohsen of the welding rollers can, instead of as shown, also lie parallel to the axes of the forming rollers, or three rollers can be arranged, one of which engages the back of the pipe, i.e. corresponds to roller 12, while instead of roller 13, two Rollers press the edges la and Ib against each other from both sides. PATENT AGREEMENT: 1. Device for the continuous production of longitudinally welded pipes in a continuous furnace heated metal strip, in which between the furnace and the rollers for the Rahrformgebung a device for electroinductive heating of the strip edges with a strip guide is provided, characterized in that the tape guide in the area of the Auf'heizeinrichtung (16j 17) consists of rollers (5 to 8) mounted parallel to the belt width, of which at least those upstream of the heating direction (16., 17) give the band a flat bulge. 2. Apparatus according to claim 1, characterized by a first inductor (16), which the strip edges heated to 100 to 200 ° C below the welding temperature, and a second inductor (17), which heats them to a temperature above the temperature of the liquid scale, wherein between the inductors (16, 17) an identical to the first pair of rollers (5, 6) is formed another pair of rollers (7, 8) and a lower guide roller behind the second inductor (17) (9) is arranged. 3. Apparatus according to claim 1 or 2, characterized in that the upper rollers (5, 7) of the Tape guide together with the inductors (16, 17) can be lifted off the tape surface, e.g. B. to a pivot point (18a) can be folded down. 4. Device according to one of claims 1 to 3, characterized in that the widths Rollers (6,8 ^) of the tape guide can be lowered, including the rear guide roller (9) by a Pivoting movement about a stationary pivot point (21). . . . Considered publications:
U.S. Patents No. 2,673,274. 2,589,541. 464583; . ,,. . French Patent No. 360 683;
Journal "Stahl und Eisen", 1941, p. 1065. 1 sheet of drawings © 908 708/102 12:59