EP0461231A1

EP0461231A1 - Sheet steel strip, process and device for manufacturing lock seam tubing with helical seams

Info

Publication number: EP0461231A1
Application number: EP19910901529
Authority: EP
Inventors: Walter Schwarz
Original assignee: SPIRO MASCHINEN AG
Current assignee: SPIRO MASCHINEN AG
Priority date: 1990-01-02
Filing date: 1990-12-04
Publication date: 1991-12-18
Also published as: WO1991009693A1; AT394815B; CA2047747A1; JPH04505889A; ATA190A

Abstract

Une bande en tôle servant à enrouler des tubes sertis à jonctions hélicoïdales présente, sur l'un de ses grandes côtés, une arête de bord (2) en saillie vers le bas et sur le second grand côté une arête en U (11) susceptible de s'engager, et laquelle vient se glisser, lors de l'enroulement, sur l'arête de bord (2) de la dernière spire. Dans l'arête de bord (2) et dans l'aile (12) libre de l'arête en U (11), il est prévu des zones déformables (4, 17) susceptibles d'être refoulées pour réduire la hauteur (h) de l'arête de bord (2) lors de l'engagement.A sheet metal strip used to wind crimped tubes with helical junctions has, on one of its long sides, an edge edge (2) projecting downward and on the second long side a U-shaped edge (11) capable to engage, and which comes to slide, during winding, on the edge edge (2) of the last turn. In the edge edge (2) and in the free wing (12) of the U-shaped edge (11), provision is made for deformable zones (4, 17) capable of being driven back to reduce the height (h ) of the edge edge (2) during engagement.

Description

Sheet metal strip, method and device for producing folded super-dovetail seams

The invention relates to a sheet metal strip, a method and a device for the thornless winding of folded screw seam tubes, the sheet metal strip being provided with an edge web protruding from a bending edge, which enters a closable U-web on the second edge during winding until a contact edge is in contact.

When core-free winding of a strip, the longitudinal edges of which are continuously folded together, for example in accordance with AT-B-316 283, 346 158 or 382 802, there are problems with regard to the dimensional accuracy of the tube cross section. These problems can already occur with the first turn, which is manually bent into a loop. Considerable difficulties arise, however, especially when winding due to the closing of the fold, which leads to a radial offset between 0.7 and 1.3 mm per turn with conventional sheet thicknesses. The reasons for this are likely to be changes in the length of both webs in terms of their shape and the extension of the protruding edge web in the bending turn, the expansion when closing and bending the fold can only be partially compensated for by compression. Usually, the circumference of the tube increases with each turn.

According to WO-A-89/05201 an attempt is made to compensate for the cross-sectional changes by means of an adjustable offset of the outer area of the sheet metal strip bearing the protruding edge web, the offset representing a step that jumps inwards in the tube, so that the circumferential length of the Edge strip bearing edge strip is smaller by the magnification error. This method is for both cylindrical as well as square tubes (with rounded edges) can be used.

In a method known from DE-A-3 324 463 for the production of cylindrical tubes, supporting rollers are provided in the interior of the winding that is formed, which contain pressure measuring cells. A reduction in the circumference increases the pressure on the rollers and an increase in the circumference reduces the pressure. By means of an electronic control unit, the measured pressure values are compared with a desired value corresponding to the desired circumferential length and a middle bending roller is changed.

Other known corrective measures in the coreless production of, in particular, welded cylindrical very-dovetail tubes relate, for example, to changes in the band edge bending (DE-A-3 137 858) or changes in the feed angle (DE-A-3 500 615).

The invention has now set itself the task of enabling the manufacture of folded tubes with a constant circumferential length without changes to the sheet metal strip itself. According to the invention, a sheet metal strip is used for this purpose, in which the protruding edge web has a crumple zone, the deformation of which allows the height of the edge web to be reduced.

A method according to the invention, in which the sheet metal strip is wound in such a way that the U-web of the incoming sheet metal strip slides onto the edge web of the last turn during winding and then the fold is closed, and the circumferential constancy of the winding that is produced is checked and in the event of an increase compared to the target value, a reducing corrective measure is initiated, provides that as a reducing corrective measure during the closing of the fold between the last turn and the incoming sheet metal strip is compressed at least the crumple zone of the edge web perpendicular to the sheet metal strip.

By forming a height-adjustable edge web, no attempt is made to achieve a change in circumference by cranking or otherwise deforming the main part of the sheet metal strip forming the tube wall, but rather to compensate for changes in circumferential length in the case of the L zschli eßung achieved by reducing the height of the edge web entering the U-web, This leads instead of steps in the edge region of each turn to steps between the deformation-free turns. Even in extreme cases, the height of the steps is no more than one and a half to two meters, and is therefore in the low celebrity values of the crude range.

The crumple zone can be in each at an edge web

Sheet metal tape feasible way. It is thus conceivable, for example, to form a strict zone in the edge web by means of longitudinal slits or punchings and to extend it to a large initial height of the edge web. In the subsequent upsetting, the height of the edge web can then be reduced to a maximum of the original height.

A preferred embodiment provides that the crumple zone comprises at least one laterally bent area between the support edge and the bending edge of the edge web.

As a result of the formation of a laterally bent-out area, the bending is increased when the height is reduced, the bent-out area creating cavities into which areas of the compressed edge web can escape or can be folded in. Furthermore, this results in the advantage that the bent edge web from the free Leg of the U-web can be gripped so that when the fold is formed, the closing of the U-web is sufficient for the firm connection. The usual folding of the closed fold is no longer necessary.

Another preferred embodiment provides that the free leg of the U-web also has a crumple zone which can be deformed together with the crumple zone of the rim web. The crumple zone in the free leg of the U-web can also be formed in any way. If, for example, an expanded metal-like zone is also provided here, the regions of the edge web and the free leg that have burrs and edges hang when the U-web is closed. A fold formed in this way can also be folded over in a conventional manner. However, the crumple zone of the free leg of the U-web is preferably also formed by a bent region, the two bent regions lying one inside the other when the fold closes.

When the eye tube is wound, the crumple zone is compressed to the desired or required extent in order to reduce the height of the edge web. This is preferably achieved by at least pressing the edge region of the last turn close to the fold relative to the incoming sheet metal strip.

A device according to the invention for carrying out this method with an outside closing roller and a counter pressure body extending into the inside of the tube provides that the counter pressure body has an element pressing against the edge area of the last turn, - the pressure surface of which is adjustable in relation to the closing roller, and that the opposite of the printing surface, the ring closing groove delimiting annular shoulder one around maximum adjustment dimension of the printing surface has reduced diameter. The ring shoulder of the closing roller lying in the edge region of the last turn is, as has been shown, only necessary for closing the fold, but not for the installation of the last turn of the tube, which presses against the counter pressure body, so that it presses against it Adjustment dimension can have the appropriate distance. The adjustment of the pressure surface therefore presses the last indication towards the closing roller, while the position of the incoming sheet metal strip remains unchanged and the height of the edge web lying with its contact edge in the U-web is reduced. The fold that closes in the process prevents springback when leaving the fold-closing device, so that the formed step is retained.

In a preferred embodiment it is provided that the element of the counterpressure body pressing against the edge region of the last turn has a rotatable sleeve and a plurality of rolling rollers mounted in the sleeve, the spacings of which differ from the axis of the sleeve. The sleeve can thus be rotated from the outside without any problems, and the maximum eccentricity of the pressure surface can be achieved, for example, after a rotation of approximately 90 °. The rolling rollers reduce the friction.

In another embodiment it is provided that the element pressing against the edge region of the last turn has a rotatable ring with an eccentric outer surface and a pressure body which is guided against the eccentric outer surface and is radially displaceably guided. The pressure body could also be formed by a roller in this embodiment and the angular range of the eccentric pressure surface is limited to a few degrees.

The sleeve or the ring can be rotated, for example, by means of a servomotor. The invention will now be described in more detail with reference to the figures of the accompanying drawings, without being limited thereto.

It shows: F g. 1 an oblique view of a flat sheet metal strip, ig. 2 to 5 the folding of a first embodiment of the longitudinal edges of the sheet metal strip, FIG. 2 the two webs immediately before their union, FIG. 3 the open fold, FIG. 4 the closed fold without upsetting the crease zone and FIG. 5 the closed one Fold represents at maximum compression. 6 to 8 the interlocking of a second embodiment in the positions according to FIGS. 2, 4 and 5,

9 to 11 show the interlocking of a third embodiment in the positions according to FIGS. 2, 4 and 5, FIG. 12 shows a schematic axial section through a few tube windings with a thread closing device, FIG. 13 is relevant to the invention Part of a first embodiment of the fold closing device in an enlarged view, FIG. 14 shows a section along the line XIV-XIV of FIG. 13, FIG. 15 shows a section along the line XV-XV of FIG. 14, FIG. 16 14 in a position rotated by approximately 90, FIG. 17 shows a section similar to FIG. 15 through a second

18, and a section along the line XVIII-XVIII of FIG. 17th

A sheet metal strip 1 according to FIG. 1 is provided on one longitudinal edge with an edge web 2 and on the other longitudinal edge with a U-web 11, which, as can be seen from FIG. 12, interlock when winding a tube and form a union 20 represent. The edge web 2 is provided on the free edge of the winding 1 ′ that is being formed, onto which the U-web 11 of the incoming sheet metal strip 1 slides. The fold 20 is closed in the winding device, which consists of the fold-closing roller 24, the body 28 and a bending tool, not shown, during winding. The bending tool is involved in the manufacture of round tubes

21 constantly, on the other hand effective in the production of angular tubes 21 only in the corresponding length lengths. Fig. 12 also shows in a greatly exaggerated representation that ge ickelte tubes 21 expand. This can be counteracted by forming steps between the turns 1 ', the height a of which can be varied. Suitable fold web designs are shown enlarged in FIGS. 2 to 11.

In the first embodiment according to FIGS. 2 to 5, each edge web 2 has a first section 8, which extends essentially perpendicularly from the bending edge 3 and to which an approximately fourth curved section 6 extends up to lower edge 5 connects. A further section 9 extends from the lower edge 5 essentially parallel to section 8 and merges into a second curved area 7, which leads obliquely upwards to the first section 8. The height of the edge web 2 to the lower edge 5 is denoted by h. The individual sections and regions of the edge web 2 thus enclose an inner cavity 10. The U-web 11 has a first leg 14, which extends essentially vertically from the bending edge 18 and is adjoined by a transverse central region 13. from which the second, free leg 12 extends upwards again, which has an outwardly bent region 15 and ends in a section 16 which projects obliquely upwards and inwards. The distances indicated with the numbers 4 and 17 correspond Crumple zones of the two webs, which are deformable during the fold closure. After the entry of the edge web 2 into the U-web 11, the edge 5 of the edge web 2 lies on the middle Iberei ch 13, as can be seen from FIG. 3. The position of the two webs 2, 11 shown in FIG. 3 is only achieved in the manufacture of angular tubes, since after each corner has been bent, the edge web 2 lies in the U-web over the entire following side length, and the closing of the fold 20 takes place during the feed. In the case of round tubes, a position according to FIG. 3 is not achieved, since the fold 20 closes at the same time as it enters. If a flush position of the inner surfaces of the last turn 1 'and the incoming sheet metal strip 1 is desired, that is to say no correction is necessary, the fold 20 is closed in the position shown in FIG. 4 with the aid of the two locking rings 26 and 27 of the locking roller 24, a groove 30 is limited. The radius of the locking ring 26 acting on the incoming sheet metal strip 1 is larger by a dimension than the radius of the second locking ring 27, so that in this position a gap corresponding to dimension a remains between the locking ring 27 and the last winding 1 '. The support of the last turn 1 'by the locking ring 27 is not necessary, since the U-web 11 rests in the groove 30 and the lower edge 5 of the edge web 2 is supported on the center Iberei ch 13 of the U-web 11. The locking ring 27 serves to push the end section 16 of the free leg 12 inwards, so that it engages behind the section 9 and the obliquely curved region 7 of the edge web 2. Since the height h of the edge web 2 remains unchanged, there is no deformation of the crumple zones 4 and 17.

In the illustration according to FIG. 5, the last turn 1 'is pressed downwards by the dimension a, that is, with respect to the tube axis 22, so that it is on the smaller one Lock ring 27 rests. On the Ro ri nnense i te, the step corresponding to dimension a is formed, by which the incoming sheet metal strip 1 is displaced inwards with respect to the pipe axis 22 (FIG. 12), so that smaller turns are formed. Here, the crumple zones 4 and 17 are now deformed, that is to say the first section 8 of the edge web 2 is pressed down until it rests on the middle 13, the first curved region 6 is bent more strongly and into the cavity 10 Folded in partially, the second curved area 7 is bent down parallel to the turn 1 'and the end section 16 of the U-web 11, which is also bent down parallel, is clamped between the area 7 and the turn 1'. The bending area 15 of the free leg 12 is more curved and pressed against the locking ring 27.

6 to 8, simplified folding webs are shown. The edge web 2 has a bent region 6 following the bending edge 3, which is enclosed by the crumple zone 4. This is followed by a section 8, which ends in the lower edge 5 lying in the U-web 11 and is not deformed. The U-web 11 in turn has a first leg 14 which extends substantially perpendicular to the sheet metal strip 1 and merges obliquely downwards into an upwardly angled center Ibere i ch 13, in the bending region of which the edge 5 of the edge web 2 - lies. The second, free leg 12 has a bent-out area 15, from which the end section 16 extends obliquely upwards. The bent region 15 and the end section 16 together form the crumple zone 17 of the free leg 12. The fold formation by the locking rings 26, 27 with flush inner surfaces is shown in FIG. 7, the free leg 12 being approximated to the first leg 14. This reinforces the angling in the middle area 13, so that the end section 16 fits the curved region 6 of the edge web 2 in the rear. 8, the last turn 1 ' Pressed downwards or outwards, the crumple zones 4 and 17 deform until the winding 1 ′ abuts the locking ring 27, as a result of which the region 6 of the edge web 2 and the end section 16 of the U-web 11 are pressed approximately parallel to the sheet metal strip. The height h of the edge web 2 is thus reduced by a maximum of the dimension a. 9 to 11. The difference from the embodiment according to FIGS. 6 to 8 consists essentially in the fact that the edge web 2 has a section 9 which is bent back obliquely upwards from the edge 5, so that the two approximately V-shaped sections 8 and 9 form an enlarged contact or support surface in the U-web 11 (FIGS. 10, 11), and an improved hold of the edge web 2 in the U-web 11, especially in FIG not reduced height h (Fig. 10) is achieved. The bent-back section 9 has approximately the same height as the section 8, so that, according to FIG. 11, the region 6 rests on the free end of the section 9 in the approach to the bending edge 3 in the case of maximally crushed crumple zones 4, 17.

The fold web shapes described are based on the mostly present requirement that a flush winding in any case leads to an enlargement of the tube, so that only reductions are necessary. In circumstances that cannot be determined exactly, a flush winding can also lead to a pipe downsizing, which can be corrected by a reverse step training. In this case, too, the sheet metal strip described can be used if it is consciously assumed that the circumferential length is too large, which is reduced to the desired circumferential length in the case of a machine-related reduction, and in the event of changes which do not achieve this dimension corresponding compression of the edge web 2 is carried out. Alternatively, the use of a sheet metal strip 1 is also possible possible, on which the first leg 14 of the U-web 11 is shortened, so that with a not reduced height h a flush starting position according to FIG. 4, 7 or 10 cannot be achieved, but an opposite step is formed between the two metal strips , in which the winding 1 'is offset upwards or closer to the tube axis 22. The crumple zones 4, 17 are then already slightly deformed for the flush winding.

Of course, in all of the fold web shapes described, the compression of the crumple zone 4, 7 and thus the change in the height h can be set to any intermediate value that results from the changes in the circumferential length checked at least once per turn 1 ′. In order to be able to press the last turn 1 'downwards or outwards - since this is a maximum of a few millimeters, it is not necessary to change the entire piece of pipe already wound - as can be seen from FIGS. 13 to 16 , the inner counter pressure body 28 has a pressure surface which can be changed at a distance from the smaller locking ring 27 of the locking roller 24. In particular, the counterpressure body 28 comprises a fixed bearing axis 29, which extends approximately over the last two turns 1 ', and a sleeve 23 rotatable on the bearing axis 29, in which rolling bodies forming the pressure surface form over a circumferential area of approximately 90 25 are mounted, the distance to the axis 29 increases. By rotating the sleeve 23 by means of an actuator (not shown), which is controlled as a function of changes in the circumferential length, that rolling element 25 is rotated into the working position which projects beyond the sleeve 23 by the required dimension a. FIG. 14 shows a roundest shape without the roll body 25 projecting, in which position the fold 20 is closed according to the representations according to FIGS. 4, 7 and 10 with flush inner winding surfaces. The maximum rotation of the sleeve 23 by 90 ° is shown in FIG. 16. In this position The steps corresponding to the maximum dimension a arise on the inside of the tube, the closure of the fold 20 following the representations according to FIGS. 5, 5, 8 and 11. For the mounting of the rolling elements 25, the sleeve 23 has bores on the end face into which the rolling elements 25 are loosely inserted. On the section of the counterpressure body 28 projecting into the tube 21, a securing sleeve 33, which axially fixes the rolling elements 25, is pushed onto the bearing axis 29 and is preferably freely rotatable on the bearing axis 29.

17 and 18 show a modified embodiment. According to this embodiment, the counter-pressure body 28 in turn comprises a bearing axis 29 on which a sleeve 23 is rotatably mounted. The sleeve 23 is connected to a ring 35 of smaller diameter, the outer surface 31 of which is eccentric with respect to the bearing axis 29, as can be seen above all from FIG. 18. The ring 35, which is smaller in diameter, extends within the securing sleeve 33, which in this embodiment is fixedly connected to the bearing axis 29 and has a radial guide slot 34. In the guide slot 34, a pressure body 32, in particular a roller, is mounted so as to be radially displaceable, which cooperates with the eccentric outer surface 31 of the ring 35. The falling out of the freely movable pressure body 32 is prevented by an external taper of the guide slot 34. 17 and 18 show that position in which the pressure surface of the pressure body 32 lies flush in the outer surface of the sleeve 23, so that in this position a fold closure according to FIGS. 4.7 and 10 can take place. If the sleeve 23 and thus the ring 35 are rotated in the direction of the arrow 36, the eccentricity of the outer surface 31 causes the pressure body 32 in the guide slot 34 to move outward, the pressure body 32 projecting by a maximum dimension a after a 90 degree rotation.

Claims

Patent claims:

1. Sheet metal strip for the thornless winding of folded screw seam tubes (21), with an edge web (2) protruding from a bending edge (3), which when winding up to the contact of a support edge (5) in a closable U-web (11 ) occurs at the second edge, characterized in that the edge web (2) has a crumple zone (4) between the support edge (5) and the bending edge (3), by means of whose deformation the height (h) of the edge web (2 ) can be reduced.

2. Sheet metal strip according to claim 1, characterized in that the crumple zone (4) comprises at least one laterally bent region (6, 7) of the edge web (2).

3. Sheet metal strip according to claim 2, characterized in that the support edge (5) is formed by a bending edge of a bent-back end region (9).

4. Sheet metal strip according to one of claims 1 to 3, characterized in that the free leg (12) of the U-web (11) has a crumple zone (17) which together with the crumple zone (4) of the edge web (2) deformable is.

5. Sheet metal strip according to claim 4, characterized in that the crumple zone (17) comprises a laterally bent area (15) of the free leg (12).

6. A method for the mandrel-less winding of a screw seam tube (21) from a sheet metal strip according to one of claims 1 to 5, the sheet metal strip (1) being so wound that the U-web (11) of the incoming sheet metal strip (1) when wrapping on the edge web (2) the last turn (1 ') and then the fold (20) is closed, and the circumferential constancy of the winding (l ¹ ) which arises is checked and a reduction in corrective action is initiated in the event of an increase compared to the desired value, characterized that as a reducing corrective measure during the closing of the fold (20) between the last turn (1 ') and the incoming sheet metal strip (1), at least the crumple zone (4) of the edge web (2) is compressed perpendicular to the sheet metal strip (1).

7. The method according to claim 6, characterized in that at least the edge region of the last turn (l ¹ ) near the fold for the compression of the crumple zone (4) is pressed outwards relative to the incoming sheet metal strip (1).

8. Device for carrying out the method according to claim 7, with a fold closing device which has an outer closing roller (24) with a fold closing groove (30) delimited by two ring shoulders (26, 27) and an inner counter pressure body (28), characterized in that the counter pressure body (28) against the edge area of the last turn

(l ¹ ) has pressing element, the pressure surface of which can be adjusted at a distance from the closing roller (24), and that the annular shoulder (27) opposite the pressure surface and delimiting the groove closing groove (30) reduced the maximum adjustment dimension (a) of the pressure surface Has diameter.

9. The device according to claim 8, characterized in that against the edge region of the last turn - (l ¹ ) pressing element of the counter-pressure body (28) has a rotatable sleeve (23) and several in the sleeve (23) bearing rollers (25) whose ab- The positions of the axis (29) of the sleeve (23) are different.

10.The device according to claim 9, characterized in that the roller rollers (25) are arranged in a circumferential region of approximately 90 ° with increasing distance from the axis (29) of the sleeve (23).

11.The device according to claim 8, characterized in that against the edge region of the last turn (l ¹ ) pressing element a rotatable ring (35) with ei¬ ner eccentric outer surface (31) and one on the eccentric outer surface (31), radially has displaceably guided pressure body (32).

12. From a sheet metal strip (1) according to one of claims 1 to 5 wound screw tube (21), characterized in that steps are provided at least between part of the turns (l ¹ ).