DE69926406T2 - METHOD AND DEVICE FOR ROLLING STEEL TUBES - Google Patents

Description

technical area

The The present invention relates to a rolling deformation method for welded steel pipes, this method being the conventional ones Use of roles independently of dimensional changes in the width of the material to be deformed allows. The present invention especially relates directly to a new roll forming process for welded steel pipes by setting the pinch edge or the pinch point (the or a special place to hold the material to be deformed with upper and lower rollers) to the boundary between the Target deformation zone and the deformed or undeformed zone in Direction of the width or width or in the transverse direction of the material and by bringing this target deformation zone in contact with the predetermined shape of the upper roller, which at the bending inside is positioned, but not the bending outside of the target deformation zone brought into contact with the lower roll to the bending deformation process perform, so that the Biegeverformbarkeit can be considerably improved rolling or rolling or rolling or rolling scratches are avoided can and according to the conventional Use of rollers or rollers in Vorverformungsbereich or Coarse deformation area for the edge bending process can be realized.

State of technology

At the Rolling of welded Steel pipes will be needed Cross-section profile by bending the steel strip gradually towards the width of the material through the use of deformation rollers produced.

At a rough deformation area, which is the first state of the roll forming process indicates the material to be deformed (which is a steel strip plate is) deformed in advance in a semi-circular shape. The thus Preformed material is then transformed by the cluster roll and the fin run or Fin-pass area where the material in an open circular cross-sectional profile is deformed, proceed.

In the aforementioned Grobverformungsbereich are usually two types of deformation methods such. B. the rolling or rolling flowers in 1 are shown applied. With the edge bending method, the material to be deformed is divided into different areas along the width and is deformed from area to area to approach the final circular shape. In the following, the bending inside refers to the position above the steel plate, while the bending outside refers to the position below the steel plate. On the other hand, in the circular bending process, the arc shape is gradually increased over the entire width of the material.

In both of the methods just described above, a pair of upper and lower contour rollers are normally used in the conventional roughing stand, as in FIG 2a is seen. For example, the pair of rollers consists of a lower roller 2 with a concave roller surface (shape) and an upper roller 3 with a convex shape. The target deformation zone of the material to be deformed 1 (in other words, both the bending inside and the bending outside of the material 1 ) is pressed into a superior roller nip.

at such conventional Deformation process, it is necessary to use the uniform roller nip, the the wall thickness the band steel plate corresponds to preset to the predetermined Radius of the arc of the material, which is the band steel plate is to create. However, this deformation process has the following practical disadvantages.

There it's an inevitable change in the plate thickness or thickness and further the material during deformation also a change is exposed to the thickness, the roller surface and the band steel plate surface is not be perfectly in place, even if the unified roll nips are selected according to the plate thickness. They are rather discontinuous to be in plant. Furthermore, things are changing the contact zone as well as the touch forces and it is impossible, these changes predict.

As a result of the aforementioned technical problems associated with the conventional type of bending methods, it is difficult to change the reference diameter of the rollers, which has a diameter corresponding to the roller surface area with an equivalent rotational speed to the Bewegungsge speed of the material in the longitudinal direction is set. Consequently, it is very difficult to synchronize the rotational speeds of the rollers along each stall and there could be a greater loss of driving forces as well as their energies. Likewise, the surface of the final rolled product will suffer from surface scratches and defects. Furthermore, since the deformation load and the drive force are asymmetrical in the width direction of the material, the band steel plate tends to rotate in the deformation process.

There both the lower and the upper roll to form a desired Rolling nip is used, there is no flexibility, this to adapt to the steel pipe, which deforms with different sizes shall be. For example, must in the edge bending process all deformation rolls are exchanged, if either the outside diameter or the wall thickness of the product changes. On the other hand, in the circular bending process, if the outer diameter the product maintains the same value, rolls traditionally applied be to pipes by adjusting the roll gap with different wall thickness when they are within a certain limit.

When The result is that the circular bending process becomes more practical considered as the edge bending method. However, the role column then become uneven and the load on the material is not sufficient be when the material is to be deformed with a relatively thin wall thickness, so that the expected deformability can not be achieved. In other Words can the conventional Use of the rollers worsen the resulting deformability.

however are to the technical problems of operational performance and Productivity, which is associated with the alternating operation of roles, technologies developed in relation to the conventional use of the rollers. One of the typical examples of the further procedures is this so-called Käfigverformungsgerüst.

With such scaffolding became the conventional one Use of the rollers by arranging a variety of small Rollers (cage rollers) instead of the conventional power rollers proposed. At the coarse deformation area is, as in the case of conventional scaffolding, the conventional one Use of roles not realized. To the number of rolls, which are to be replaced, not only the deformation load in the Vielwalzenverformungsbereich, but also a part the deformation load originally in the gross deformation range accomplished to the cage deformation area shifted so that reduces the number of coarse deformation levels can be.

however the deformation function of the cage rollers is extremely limited. And that is, each cross-sectional area of the material with a not uniform bending moment deformed, since the contact area between the cage rollers and the material to be deformed is very small. The deformability Such a free-floating method depends strongly on the size and the Material properties of the product. Accordingly, it is very difficult, the desired Sheet shape distribution as it has been designed to receive.

Especially there are many ways if the overbending phenomenon on the central area of the steel plate occurs on which the largest bending moment usually acts. Even if the inner roll (which is the convex roll) is used, it is impossible to make the bending moment uniform.

There the excessive deformation work the cage deformation area zugewießen negative effects also affect the deformation function and stability of the entire scaffolding system. Accordingly, many problems with these types of scaffolding or mill system known in which the roles conventional be used.

Around to eliminate the aforementioned disadvantages associated with the cage-like scaffolding system United States Patent No. 4,770,019 issued a Rolling respectively.

Walzverformungsverfahren proposed, which is hereinafter referred to as FF-flexible deformation method. The document US Pat. No. 4,770,019 is a roll forming method for deforming a tube from a strip having a bending inside and a bending outside. The strip is positioned between at least a pair of an upper roll and a lower roll. The upper and lower rollers are applied to the strip in a deformation area in which the strip is roll-deformed by the upper and lower rollers so that the strip winds around the roller surface of the upper and lower rollers. Therefore, the strip is loaded by both the lower roll on the outside of the bend and the upper roll on the inside of the bend. Furthermore, the this document no pinch edge or no pinch point.

in the In general, in the FF deformation process, the conventional Use of the rolls not only in the multi-roll forming area, but also in the gross deformation range by using a special role can be realized, the shape of an involute, which changes its arc shape radius either continuously or stepwise), corresponds and by applying a position control mechanism for transmission and rotation of such rollers.

In order to bend the edge portion of the material which is the most difficult to deform portion, the in 2 B shown roller assembly used in the so-called No. 1 rough or rough stand. According to the roller arrangement for the FF deformation method, the upper roller is 3 (convex roller) or the lower roller 2 (concave roller) provided with suitable involute curves according to the limits of the inner and outer diameter of all relevant products.

Although the roll nips deformed with these rolls are usually not uniform, the upper and lower roll positions are determined to be the preferred roll nips at the edge region of the material 1 according to the size of the product to be deformed. By using this deformation method, it is possible to perform an edge bending without a roll change, so that the deformability is improved over the entire framework.

however Even with the FF deformation method, the circular bending deformation method is basically included Reference to the stalls except used the No. 1 coarse. As a result, the most the deformation work still in the Vielwalzenverformungsbereich carried out.

US 4,770,019 discloses a method and apparatus for applying this method for (1) deforming a tube from a strip having a bend inside and a bend outside and a target deformation zone, wherein the roll deformation between at least a pair of upper roll and a lower roll, the method Steps involves applying an upper roller to the inside bending side of the strip and applying the lower roller to the bending outside of the strip; (2) winding the target zone of the strip around the roller surface of the upper roller on the bending inner side loaded from the bending outside by the lower roller is. The disclosed method and apparatus are directed to the deformation of large or small diameter pipes by using a single set of forming rolls. Therefore, a part or the entire sectional curve of the roller surface of the upper and lower deformation rollers of the deformation roller for bending the edge of a strip is designed to mate with the lower arcuate surface of the lower deformation roller in the edge bend of the strip when it is wide and with the upper curve surface the lower deformation roll in the edge bend of the strip when it is narrow to match the curve of the edge portion of the strip. This document further discloses a roll forming apparatus having a piece of a split lower roll and a pair of upper rolls, wherein the axial direction of the rotary axes of the upper roll can be changed to assist the material to be deformed.

epiphany the invention

consequently It is therefore an object of the present invention to the aforementioned Disadvantages that are shown in the above articles to eliminate a new roll forming process and apparatus for the same reason, with those, basically without a deterioration of any advantage of the conventional ones Use of the rollers in the FF deformation process, the the circular bending method uses the fact that the Deformation work of the FF deformation process mainly in the Hot roller deformation area is positioned, which shows the weakest deformability, can be modified, the deformability at the coarse deformation range be enlarged and the overall deformability can be considerably improved can.

The The present invention has proposed a novel deformation method (Japanese Patent Publication No. 2000-084619, PCT / JP98 / 04962, published on 29.02.2000 and EP-A-0988905, published on 29.03.2000), in which the edge bending process in the FF deformation process is introduced and a plurality of edge bending levels in the coarse deformation area is used to improve the deformation function, and about half Zone of the width of the plate area by area of its edge sides is deformed ago.

By the aforementioned method, which is now referred to as FF / X deformation method, are improves the overall deformability and stability of the scaffold system. However, the bending process as in 2 B Usually, the FF deformation method is used only for deforming the edge portions of the material, and it is difficult to set the proper roll pitch for the case where the target deformation zone is relatively wide.

Even with these continuing Procedure of FF or FF / X method is not the basic system concept of a conventional one Type different, in which the inner and outer surfaces of the material are sandwiched disposed between a pair of concave and convex rollers are and pressed into the roller gap become. Furthermore, this deformation process has a technical Concept, such that, although not expected, the target deformation zone in contact with both the concave and the convex roll Because the involute of the circumference is used, it is the appropriate one Role surface areas the convex and concave roll are chosen to hold the material in to bend the roller gap into a shape similar to that of the roller gap as similar as possible.

The current Inventors have conducted experiments and analyzes to examine the relationships between the roller assembly / orientation and the deformation functions too investigate the deformation function in the gross deformation range to improve while Effectively uses all the advantages of FF, FF / X deformation processes be it possible make the rolls in the pipe scaffold system conventional Way to use. As a result of extensive investigations are the present inventors come to the conclusion that to the material in a desired shape it is essentially not necessary to bend a pair of one concave and convex contour roll apply.

And though the present ones have Inventors found that by winding a portion of the Cross section of the material to be deformed, the predominant herein is called a target deformation zone to either one entire or an area of the surface of the convex roll, the has a roll shape with a certain arc shape distribution, the almost entire arc shape distribution to the target deformation zone of the Material can be applied without the opposite surface through Use of the concave roll as practiced conventionally is to burden or urge or restrict. Here, this new bending process is referred to as "embrace bending".

For example, the same deformability can be achieved by using the roller assembly as in 3 instead of providing a pair of convex and concave rollers as shown in FIG 2A be achieved shown. In the foregoing case, the control of sheet shape distribution becomes mainly by the upper convex roll 12 carried out. Although a pair of left and right lower rollers are used, the principal function of these rollers is to provide a support force around the target deformation zone about the convex roller surface 12 to wind so that the embrace bend can be performed. In other words, the target deformation zone of the material can be controlled and supported in such a way that it is in contact with the convex roll peripheral region whose arc shape distribution is expected to be applied.

It There are several important points in connection with the above Embrace-bending process. First, the pinch point, the one creates minimal distance between the convex and the concave rollers, set to a specific location to the position of the material to control in the direction of the width. Second, the target deformation zone of the material around the peripheral portion of the convex roll on the inside of the bend wound around the expected bending strain distribution to the target deformation zone without a load on the material from the outside of the bend apply.

If the driving force has to be generated, the minimum distance should be between the convex and concave rollers at the pinch edge equal to the wall thickness be sufficient amount of pressure or frictional force to obtain. Both surfaces of the material are loaded simultaneously only at the pinch point.

A Such pinch edge is designed and in the border area between set the target deformation zone and other areas of the material. This is the other way round the area that has been previously deformed is inclusive the bend-insensitive zone of the edge area of the material or the undeformed area of the material.

On the other hand, it is not essential to load the inner and outer surfaces of the material simultaneously at the crimping edge when the driving force is not needed. Instead, it is simply necessary to set the position for the concave roller to the target deformation zone around the convex rollers area to wind.

According to claim 1, the first aspect of the invention is a roll forming process for deforming a tube from a strip with a bending inside and a bending outside and a target deformation zone, wherein the roll deformation between at least a pair of upper roll and lower roll takes place the method comprising the steps of: forming a pinch edge by applying an upper roller to the inner bending side of the strip and applying the lower roller to the bending outside of the strip, seating the squish edge to a boundary between the target deformation zone and an adjacent region of the strip and winding the target zone of the strip around a roll surface the upper roll at the bend inside without through the lower roll from the bend outside limited here or to be burdened.

Therefore In the present invention (1), the zone is in the direction the width or in the transverse direction of the material to be deformed in set at a certain level as the target deformation zone, (2) the squeezing edge or pinch point becomes the boundary between set the target deformation zone and other areas of the material, to the desired Arc deformation distribution by winding the target deformation zone around the area the convex roll mounted on the inside of the bend, and (3) the lower roller circumference is offset such that it Do not roll in contact with the target deformation zone from the bend outside It will be like the conventional one Procedure makes. As a result, it is not necessary to conventional To provide a type of roller circumference, since the concave roller is not directly is affected by the arc shape distribution of the target deformation zone to control.

Of Further find according to the present new rolling deformation process hardly takes place, since the target deformation zone of the material basically only by the convex Role is charged. Still further, the occurrence of the excessive deformation stress to the utmost controls what This results in steel tubes with an excellent second Deformability can be generated. This is the first advantage of the present new roll forming process.

Further nor can the roller diameter at the pinch edge be understood as the reference roller diameter when the rollers are driven. Because the position of the pinch edge is very accurately identified and does not vary, it is easy to synchronize the drive speeds between each booth. This is the second advantage of the present new roll forming process.

Further more, even if the surface pressure at the crimping edge within a certain limit due to the Fluctuation of the wall thickness varies, the symmetry can be maintained with respect to the left and right sides and no rotation of the material is caused because the condition of contact between the material and the roles does not change. This can be another Advantage of the present new Rollverformungsverfahrens viewed become.

When a result will make it possible the deformability and stability of the scaffolding system through introduction of the embrace bending concept of the present invention in conventional Strongly improve pre- and coarse deformation ranges. Further still it according to the present Invention simple, since it is not necessary that both the concave and the convex roll the exclusive sizes according to size of too deforming product, the conventional use of roles perform. This should be the further advantage of the present new roll forming process be.

Other advantageous features of the method invention are described in the dependent claims 2 to 9 set forth.

According to claim 10, a second aspect of the invention resides in a roll forming apparatus for performing a roll forming method of forming a tube from a strip having a bend inside and a bend outside and a target deformation zone, the roll forming apparatus having: (a) a one-piece or split lower roll, (b ) at least a pair of upper rollers in the width direction of the material, and (c) a pair of side rollers provided horizontally at the edge portion of the material, wherein the axial direction of the axes of rotation of the upper and lower rollers can be changed independently of each other to support the deformed material, wherein, when using the device, the roll deformation takes place between at least a pair of upper rollers and lower rollers, the side rollers in abutment with the previously deformed zones of the material from the outside of the bending ago to the bending back ph Noun to avoid, wherein the device is provided in a process comprising the steps to be used: (i) forming a squish pp by applying the (ii) setting the squish edge pp at a boundary between the target deformation zone and an adjacent region of the strip, and (iii) winding the target deformation zone of the strip around a roll surface of the upper roll at the inside of the bend without passing through the bottom roll to be limited from the Biegeaußenseite ago.

The Target deformation zone is the part of the strip that is in the top roll-formed or mentioned process of the present invention. is roll formed, which is a step in the deformation of a pipe. It is not the entire width of the strip in the entire tube forming process deformed.

Short description the drawings

The The above and many other objects, features and advantages of the present The invention will become more fully apparent from the following detailed description the embodiments of the present invention, their description in conjunction should be read with the accompanying drawings.

1 is a drawing to explain the roll flower at the coarse deformation area, where A stands for the edge bending method and B stands for the circular bending method.

2 Fig. 12 is an explanatory figure of the roller assembly of the conventional type of coarse deformation stands, wherein A stands for a pair of upper and lower rollers, and B stands for the rollers of the FF deformation method.

3 Figure 13 is a figure of the roller assembly to explain the "embrace-bending" concept of the present invention.

4A and 4B show the roller assemblies in which the "embrace-bend" concept of the present invention is applied in coarse deformation stages.

5 shows a coarse deformation state in which the "embrace-bending" concept of the present invention is applied to a welded steel pipe which is deformed under conventional use of the rolls, where A stands for the case that pipes having a large diameter are deformed B stands for the case that pipes with a small diameter are deformed.

6A . 6B and 6C show the roll forming method and the roller assemblies of the roll stands for the coarse deformation area according to an embodiment of the present invention.

7A shows a perspective view of the roller assembly of the pipe frame when the Rollverformungsverfahren and its device of the present invention are applied, wherein 7B a figure is to explain the roller assembly of the reverse bending deformation region, and 7C a figure is to explain the roller assembly of the Vielwalzenverformungsbereiches.

8A . 8B and 8C show the roller assembly of the roller stand for the coarse deformation region according to another embodiment, when the roll forming method and apparatus of the present invention are applied.

9A is a perspective view of the roller assembly of the other roll stand, when the Rollverformungsverfahren and the apparatus of the present invention are applied, wherein 9B a figure is to explain the roller assembly of the reverse bending deformation region, and 9C a figure is to explain the roller assembly of the Vielwalzenverformungsbereiches.

10 shows the case when the auxiliary rollers are mounted on the coarse deformation stand, where A is a front view and B is a side view.

11 Figure 12 shows geometric locations of the edge region of the material in the coarse deformation region, where A and B are a side view and a top view when the pass line is set to form the bottom of the roll flowers as a straight line.

Preferred embodiment to carry out the invention

This is according to the invention Embrace bending process basically for all types of deformation stands and deformation processes applicable and it is possible to streamline the existing deformation processes. However, when considered as one area of conventional usage technology the roles is applied, the excellent function can be observed that are not traditional Deformation process can be realized.

It It should be noted in particular that the present new bending process is indispensable to the continuing conventional To establish use technology of rollers or rollers, the based on the edge bending deformation method with a strong Deformation function as the aforementioned FF / X deformation method. In the following you can the roller assemblies and the roll forming method by which the "Embrace Bend" concept as of the current one Defined inventors can be practiced, and the conventional Use of roles can be realized.

As in 4 shown, the roller assemblies are in the roughing state of 2 B modified to perform the "embrace-bending" method of the present invention. First, as in 4A shown, the pinch pp positioned at a location a certain distance away from the plate edge. The area of the squish edge pp to the plate edge is considered to be the bend insensitive area 1a referred to as the sufficient bending moment is not normally achieved.

Although the area of the bend-insensitive area 1a Depending on the product dimensions and the type of material, it can be defined as having usually the same thickness as the plate. The bend-insensitive area 1a , which is positioned at the bottom of the squeezing edge pp, passes through the lower roller 20 supported and the target deformation zone 1b , which is arranged on its inside, becomes the upper roller surface 21 twisted to be bent.

Therefore, the pinch point pp is between the bend-insensitive area 1a and the target deformation zone 1b set. The touching surface of the lower roller 20 has a flat surface to avoid stressing the target deformation zone from the bending outside.

In order to meet different diameters, it is necessary to adjust the positions of the lower and upper rollers. In addition, it is necessary to select an area of the upper roller surface with a proper sheet shape distribution to contact the target deformation zone, because the degree of deformation is mainly due to the roller circumference of the upper roller 21 is controlled.

When the range of conventional use of the outer diameter rollers of the product is relatively wide, it is preferable, similar to the FF deformation method, to have an involute shape on the upper roller 21 and to use the support mechanism with which the supporting axial direction of the roller is freely changeable to not only move the roller in parallel, but also to rotate, so that an appropriate range of the circumference can be selected to contact the target deformation zone.

It is not necessary to use the involute form on the lower roller 20 to provide, as previously described. If the role flower is properly designed, it is possible to perform deformation operations of different pipe sizes even with the linear shape, as in 4A is seen to suit.

If the occurrence of roll marks or roll defects is expected due to the type of material or the ratio of wall thickness diameter, t / D, the involute shape may also be on the lower roll 20 be provided so that the material edge region can be supported by the roller surface area, which has an arc shape similar to that of the product.

On the other hand, although the embrace bend essentially does not require it, the central role 22 and to form the W-like cross section of the material, it has a favorable effect to extend the area of the target deformation zone. The figure of the central role 22 and their position can be set in such a way that to deform products of all different sizes, the expected target deformation zone safely around the upper roll 21 should be wrapped.

In the 4A Roller arrangement seen is very effective to bend the edge region, and it is also applicable to bend other areas of the material. However, it is also necessary that support previously deformed zone to prevent the Zurückbiegephänomen when the range of conventional use of the rollers is large, while the Zielverformungszone is provided with the predetermined arc shape distribution.

Therefore, the in 5A shown roller assembly extremely effective to form Zielverformungszonen except the deformed edge portion. This roller arrangement will, though the central role 30 similar to the case in 4A not only applied to improve the embrace flexing efficiency but also around the pinch point pp by combination with a pair of the upper rollers 31 . 32 to generate the driving force.

Furthermore, with the roller assemblies in the 5A and 4B unlike 4A , Side rolls 33 . 34 intended. These page rolls 33 . 34 are in contact with the aforementioned previously deformed zone to prevent the bending-back phenomenon. At the same time is the target deformation zone 1c , which is arranged on the first side of the pinch edge pp, by using the bending moment caused by the deformation force of the side rollers 33 . 34 caused to the upper rollers 31 . 32 effectively wrapped.

On the other hand, the bending moment, as in 4B shown at the previously deformed zone 1d small; That is, the lever of the bending moment is short, since the working position of the side rollers is within the pre-deformed zone, so that this zone is not subject to much deformation.

Even the small size rolls can be used instead of the side rolls 33 . 34 be applied to prevent the previously deformed zone from bending back, so that it is possible to arrange a plurality of small rollers along the longitudinal direction of the material in the above roller assembly.

Since the control of the arc shape distribution of the target deformation zone by the upper rollers 31 . 32 Even with the above-mentioned roller arrangements, it is preferable to use the involute form in these rollers 31 . 32 to use and these roles 31 . 32 to rotate and / or move in parallel in the direction of the width of the material to select the peripheral region to contact the target deformation zone of the material.

The side rolls 33 . 34 be the same as the bottom rollers 10 . 11 in 3 needed to make at least the parallel motion to match the deformations of the different product sizes. Furthermore, it is preferable to provide suitable types of involute to prevent the occurrence of rolling defects or rolling marks as much as possible. 5A shows the roller assembly for the case when the tubes are deformed with a relatively large diameter, while 5B the roller arrangement for the case shows when the tubes are deformed with a relatively small diameter.

The similar Description can for the central roles are made. It is preferred to be separate To use rolls such as two-way or three-way rolls, which is better than a one-piece role, as seen in the figures becomes. It will be easier to set the target deformation zone of the material to bring a certain area of the circumference of the upper roll through a suitable selection of the position of the central role in To touch direction of width or vertical.

On on the other hand, the deformation rollers in the roughing stands suffer, in particular in the deformation state in which the edge bend is performed, at the wear damage because of the big one Deformation load. Furthermore, it is known that an edge stretch, which is the main reason for the edge wave is inclined to take place at these stands.

Of the Roller wear and the edge wave mentioned above will appear even then when the embrace bending process of the present invention is used. However, the present inventors have found out that auxiliary rolls of small size, which are in abutment with the edge of the material are nearby the upper and / or lower flow of the coarse deformation stands mounted can be so that part of the deformation load is assigned to the auxiliary rollers what results is that the deformation load and the Surface pressure which act on the lower roll can be reduced.

As in the 10A and 10B can be seen, the edge area of the material 1 Gradually rise while he is the center of the upper roll 40 or lower roll 41 approaching in the rough deformation state. In an earlier state of the bonding process, only the sharp outer edge corner of the material will engage the lower roll surface 40 be.

In this state, since the contact is mostly the edge or point contact, the roller load can be easily due to the abnormal high surface pressure. To avoid this abnormal roll wear, as in 11A shown a pair of small non-driven second auxiliary rollers 53 . 54 near the upper and lower river near the lower rolls 50 . 51 mounted to the outer edge corner of the material 1 to touch, leaving the edge area of the material 1 can be supported.

If the auxiliary roles 53 . 54 are provided in the upper flow as described above, the outer edge corner of the material in abutment with the auxiliary rollers 53 . 54 come before they the deformation rolls 50 . 51 touched. In such a case, when the material moves in the direction of the deformation rollers 50 . 51 moved, the edge region of the material is already raised by a certain amount or increased. After it's the bottom rollers 50 . 51 has touched, the contact area increases quickly, so that the abnormally high surface pressure can be prevented.

Still further, the contact of the auxiliary rollers dulls 53 . 54 the outer edge corner of the material and reduces the possibility of the occurrence of abnormally high surface pressure. Furthermore, a part of the deformation load by mounting the second auxiliary rollers 53 . 54 the auxiliary rollers 53 . 54 assigned and the deformation load and the surface pressure acting on the lower rollers 50 . 51 works, can be reduced.

If the auxiliary role 53 is provided only in the upper stream, it is preferable, the material fixed along the longitudinal direction by mounting the auxiliary roller 55 to load on a lower river side of the deformation state, since the steel strip along the longitudinal direction around the upper roller 52 will turn, as the supporting point and the effect of the auxiliary role 53 is reduced if there is no auxiliary roller, which is mounted on the lower river side of the deformation state.

at of the present invention The wear problems of the auxiliary role can not be prevented. however can the role itself and its support mechanism very easy to be compared with the deformation rolls, since the Auxiliary role according to the present invention, a non-driven Type is of small size, so that the equipment and maintenance costs are low and replacement work for polishing these roller surfaces are also simplified.

Further nor are deformability and product quality adversely affected, even if they are worn out, since the essential task of the second auxiliary role is to support the edge of the material and she just touches the edge corner of the material. For such a case is it is not necessary to replace and polish these auxiliary rollers.

The The auxiliary roller described above not only controls the wear phenomenon of the Deformation role, but also it has a great effect to prevent the so-called edge wave of the material, due to the excessive edge stretch during the deformation process is caused. The appearance of this edge stretch is the most remarkable in the coarse deformation area.

It is usually believed to be the indication that the spatial transmission distance in the width of the edge portion of the material due to the jump back between the stalls longer is one of the main reason in other areas, the edge stretch to cause. However, according to what the present ones Inventors observed in the context of their extensive experiments and analyzes have found out that the effect of springing back not at the differences in the regional geometric places is great rather, the edge wave finds mainly due to the fact instead, the edge area is stretched locally as it moves along the roller surface increases.

As in 10B is seen, the edge area wraps itself 1 around the surface of the lower roll or roller 40 and increases when the material 1 enters the roller gap. Because during this short period of time the S-shaped regional geometric place 42 which is formed by the edge portion is much longer than the nearly linear geometrical positions formed by other portions, a large edge stretch occurs. Still further, a downward tendency will be due to such edge stretching in the longitudinal direction of the material after the material has passed the roller nip, causing the same increasing problem in the following situation.

To solve this problem, the height of the edge portion before entering the roll nip may be set to the same level as or slightly higher than the edge portion in the roll nip make the geometric location of the edge area narrow to be linear as much as possible.

However, even if the transit line 44 As set out above, the edge area becomes the height of the other areas of the material due to the load from the rollers 40 . 41 goes down, the superior passage line 44 leave and continuously go down to the position where they are with the geometric location 46 the other areas is balanced. Then the geometric place 45 the edge area along the lower roller surface 40 increase. As a result, the effect of reducing the growth of the edge area is by setting the passage line 44 very low.

As will be clearly understood from the foregoing analyzes, it has been found that, before the roll nip is entered, the strength of the edge portion of the material itself can not maintain the preselected passage line. However, the assembly of the second auxiliary roller as in 11 seen solve this problem.

It is according to the invention not necessary, since the auxiliary role does not directly contribute to the deformation products, the roll size in relation to the dimensions to shape the products as it is done for the deformation rolls has been. The flat rollers can used when the edge corner of the material to the desired Position not supported can be. Furthermore needed the auxiliary role is just a simple support device, the front and rear of the deformation state is mounted, so the exclusive stand just for the auxiliary roller not required becomes.

In the present invention, the shorter distance (clearance) can be obtained when the auxiliary roller is positioned at the same level as the lower roller because the shorter the distance (distance) from the base of the edge corner of the material to the center of the lower roller is the shorter greater different effects are achieved by the auxiliary rollers. Furthermore, it is to get the short distance as in 7B shown extremely effective to tilt the axis of the auxiliary roller in the direction of the center of the lower roller in the longitudinal direction.

If the size of the product changes and the same auxiliary role does not correspond to these changes, it is obviously necessary to exchange the roles. however can the conventional Use of auxiliary rollers can be achieved when the roller flowers designed in such a way that the positions the edge corners lie on a certain curve.

embodiments

Embodiment 1

Related to the 8th and 9 For example, the embodiment of applying the roll forming method and apparatus of the present invention will be described to the roll assemblies Nos. 1 to 3 in the rough deformation area in the pipe stand system of the FF / X deformation method previously proposed by the present inventors. In such a pipe skeleton system, as clearly in 9A is seen, roller stands BD1, BD2, BD3, which are arranged on the coarse deformation region, followed by the roll stand RB at the reverse bending region, the cluster roll C1 to C6 in the Vielwalzenverformungsbereich and of the roll stands FP1, FP2 in the Flossendurchlaufverformungsbereich.

In the roll stand BD1 of the coarse deformation area, as in 8A is seen, a rotation-type pair of left and right upper rollers mounted, which can change the contact direction against the material, and a pair of left and right lower rollers together with the central roller, which is built narrow. Between the upper and lower rollers, the pinch point is set in the boundary region between the target deformation zone in the width direction of the material and in the transverse direction, which is ready to be deformed at the BD1 level, and the bending-insensitive edge portion of the material , Such a pinch edge has the same mechanism and function as in FIG 4A described to perform a certain edge bending operation.

The roll stand BD2 consists, as in 8B is seen to consist of a rotational type pair of left and right upper rollers, a wide lower central roller and a pair of horizontal rollers to support the edge portion of the material previously deformed in the BD1 roller stand has been. Between the upper roller and the shoulder portion of the central roller, the crimping edge in the boundary between the target deformation zone, which is intended to be deformed in the state BD2, and the undeformed zone of the central portion of the material is arranged to have the same mechanism and function as in 4B described to perform the bending operation.

Of the Roller stand BD3 has the same mechanism and function as the previous roller stand BD2 and is used to the target deformation zone to bend, the closer at the materials center. The area of the material on the outside the Zielverformungszone, already in the previous role levels BD1 and BD2 is deformed by the horizontal roller with a Involute shape supported, so that the back bend the deformed area on the outside of the target deformation zone is prevented.

In the next step, the central portion of the material pushed up from the central rollers at BD1, BD2 and BD3 becomes the roller stand RB as shown in FIG 9B is seen, vice versa. Therefore, the introduction of the material into the multi-roll forming area becomes much easier. Further, the cross section of the material is deformed into a profile similar to an open circle by the following fin passage deformation regions FP1, FP2.

When using the pipe system, as in 9A According to the present invention, the edge bending deformation process is carried out without changing the rollers at the rough deformation range, so that the deformability is extremely improved and the conventional use of the rollers in a range of about three folds in diameter ratio is achieved.

Embodiment 2

In a conventional type of FF deformation method, referring to FIGS 6 and 7 another embodiment of the application of the Rollverformungsverfahrens and the apparatus of the present invention to the roller assemblies Nos. 1 to 3 of the coarse deformation range described. The tubing has, as in 7A is seen, roll stands BD1, BD2, BD3 at the rough deformation area, roll stand RB of the reverse deformation range, multi-roll stands C1, C2, C3 and roll stands FP1, FP2 in the fin pass-through deformation area.

In the roll stand BD1 in the rough deformation area, as in FIG 6A is seen, a rotation-like pair of left and right upper rollers, which are changeable in the contact direction with the material, a narrow central roller and a pair of left and right lower rollers mounted with a involute circumference. Between the upper and lower roller pairs, the pinch edge is provided in the boundary between the target deformation zone prepared to be deformed in the roller stand BD1 and the bending insensitive zone of the edge portion of the material. Such a pinch edge has the same mechanism and function as in the 4A described to perform the edge bending operation. The target deformation zone is not in contact with the roller circumference of the lower roller other than its limit at the squish edge (not shown in the figure).

In the roll stand BD2 are, as in 6B a rotation-type left and right pair of upper rollers and a pair of left and right lower rollers are provided. Between the upper rollers and lower rollers having the involute shapes, the squish edge is provided in a boundary between the target deformation zone ready to be deformed in the reel stand BD2 and the previously deformed zone deformed in the reel stand BD1. Such a squish edge provides the same mechanism and function as in FIG 4B Again, the target deformation zone is not in contact with the roller circumference of the lower roller except its limit at the squish edge. On the contrary, the material edge portion, previously deformed in the roll stand BD1, is in abutment with and supported by the involute shape of the lower roll to maintain the expected ductility.

The roller stand BD3 has, as in 6C is seen, the same mechanism and function as the previous role status BD2. In this state, a target deformation zone is bent, which is closer to the center of the material. The material edge portion, which has already been deformed at the previous roller stands BD1 and BD2, is supported along the involute shape of the lower roller, so that the bending back of the deformed portion is prevented.

In the next step, the central area which has been pushed up by the central rollers at BD1, BD2 and BD3 becomes the reel stand RB as shown in FIG 7B is seen, vice versa. Therefore The introduction of the material into the multi-roll forming area becomes much easier, as clearly in 7C is seen. Further, the cross section of the material is deformed into a profile of approximately an open circle by the following fin passage deformation regions FP1, FP2.

By using the pipe system, as it is in 7A In the present invention, the edge bending method can be performed without replacing the rollers in the coarse deformation area, so that the deformability is extremely improved and the conventional use of the rollers can be achieved in a range of about two and a half folds in diameter ratio.

Embodiment 3

at Use of the pipe scaffold system for welded steel pipes, which three units of deformation levels to the gross deformation range according to the FF / X deformation method applies, the auxiliary rollers are in an add-on manner before and arranged after the coarse deformation range. The edge stretch the steel plate was at each stand at the gross deformation area measured. Table 1 shows the results for three cases; and that includes them (1) no auxiliary roller, (2) auxiliary rollers before and after the roller stand BD1 and (3) auxiliary rollers before and after roller stands BD1 and BD2.

In In the case where no auxiliary roller was mounted, a large edge stretch became at the roll stands BD1 and BD2 observed. On the other hand, though was the edge stretch could not be completely eliminated, in the case when the auxiliary rollers before and after the roll stand BD1 were mounted, the recorded Value of edge stretch less than half for BD1 and about a quarter at BD2.

Further was still, if the auxiliary roles also before and after the role stand BD2 were mounted to support the edge area of the steel plate, the Edge extension at the BD2 stand reduced even further for another half. From this result, it is clearly understood that the auxiliary role has a very effective function to the edge stretch to prevent.

Of Further, Table 2 shows the results of the actions of the auxiliary role on the thrust and the deformation load on the roller stand BD2. Based on the presented in Table 2 Results show that the boost to the BD2 role status and the deformation load acting on the lower roller is very high are different from the case when the auxiliary role before and after the role status BD1 is not provided, and the case when the Auxiliary role before and after the role stand BD1 is provided.

The introduction Namely, the material in the roll nip can be greatly improved due to the fact that the edge enhancement is considerably reduced is due to the effects of the auxiliary role. Furthermore, the Effect of thrust and deformation load very significant.

Table 1

Table 2

Industrial Applicability

According to the invention Crimping edge formed by the upper and lower rollers is at the boundary between the target deformation zone in the width direction of the material and the previously deformed zone or undeformed Zone set. The target deformation zone will be around a certain extent the upper roll, which is positioned on the bending inside, wound and bending deformed in such a way that the lower Roller is almost not in contact with the target deformation zone. When As a result, the bend formability can be much improved and roll errors and roll marks can be prevented.

Corresponding the roll forming method of the present invention the concave roll does not directly contribute to the control of the arc shape distribution the target deformation zone. On the other side becomes the target deformation zone in principle just pushed by the convex role, leaving an excess of deformation hardly takes place and the occurrence of superfluous strain can be prevented.

Of Further is the maximum surface pressure generated at the pinch edge when the roller is driven. There the roll diameter corresponding to the pinch edge, is used as a roll reference diameter and the position the squeezing edge is clearly identified and can not change The drive power is very easily synchronized along each roller stand become.

Of Further, in the roll forming method of the present invention the contact condition between the material and the rollers independent of changes in the wall thickness the material is stable, so that the rotation phenomenon is not caused.

Corresponding the roll forming method of the present invention is because it is not necessary that both the concave and the convex Roller rollers are equivalent to an exclusive roller circumference the product to be deformed, the conventional use of the rollers easy to realize. Likewise, the deformation function and the operation the work substantially by the introduction of the invention in the Grobverformungsbereich be improved.

Of Further, by supporting the edge of the material at the preselected height the auxiliary role in an area near the upper river and lower Flow of the lower roll of the roughing stand, the deformation load and the surface pressure, which act on the lower roll can be reduced. As a result the local wear of the roll can be reduced. Similarly, deformation defects like the edge wave caused by local stretching of the edge area caused to be eliminated.

Claims (10)

Roll forming method for forming a tube from a strip ( 1 ), a bending inside and a bending outside and a target deformation zone ( 1b . 1c ), wherein the roll deformation occurs between at least one pair of upper roll and lower roll, and wherein the method comprises the steps of has: i) forming a pinch edge (pp) by applying an upper roll ( 12 . 21 . 31 . 32 . 41 . 52 ) to the bending inside of the band ( 1 ) and by applying the lower roller ( 10 . 11 . 20 . 30 . 50 . 51 ) to the bending outside of the band ( 1 ); ii) setting the squish edge (pp) to a boundary between the target deformation zone and an adjacent region (pp) 1a . 1d ) of the band ( 1 ); and iii) winding the target deformation zone ( 1b . 1c ) of the band ( 1 ) around a roller surface of the upper roller ( 12 . 21 . 31 . 32 . 52 ) on the bending inside without through the lower roller ( 10 . 11 . 20 . 30 . 50 . 51 ) to be restricted from the bending outside. Roll forming method according to claim 1, wherein side rolls ( 33 . 34 ) abut the previously deformed material zones from the outside of the bend to prevent the bending-back phenomenon. Roll forming method according to claim 1 or 2, wherein the contact roller from the bending outside the center area of the material in the transverse direction, to form a W-shape of the cross section. Roll forming method according to one of claims 1 to 3, wherein a roll form formed of a plurality of sheets is. Rolling deformation method according to claim 4, wherein the Roll shape of an involute corresponds. Roll forming method for welded steel tubes, wherein the deformation method according to one of the preceding claims is used in the pre-formed deformation range. Roll forming method according to one of claims 1 to 6, wherein an auxiliary roller ( 53 . 54 mounted on the edge of the material and in a vicinity of the upper roller ( 12 . 21 . 31 . 32 . 52 ) and lower roll ( 10 . 11 . 20 . 30 . 50 . 51 ) in deformation racks, and the auxiliary role ( 53 . 54 ) is used to maintain the height of the edge of the material at a level previously reached during roll forming. A roll forming method according to claim 2, wherein a roll forming device is used which has a one-piece or split lower roll ( 30 ), a pair of upper rollers ( 31 . 32 ) in the transverse direction of the material and a pair of side rollers ( 33 . 34 ) provided in the horizontal direction of the edge portion of the material. A roll forming method according to claim 2, wherein a roll forming device is used which has a one-piece or split lower roll ( 30 ), a pair of upper rollers ( 31 . 32 ) in the transverse direction of the material and a plurality of rollers arranged longitudinally to abut the edge region of the material from the outer side. Roll deformation device for carrying out a roll forming process for forming a tube from a strip ( 1 ), a bending inside and a bending outside and a target deformation zone ( 1b . 1c wherein the roll forming apparatus comprises: (a) a one-piece or split lower roll ( 30 ); (b) at least one pair of upper rollers ( 31 . 32 ) in the transverse direction of the material; and (c) a pair of side rolls ( 33 . 34 ), which are provided in the horizontal direction of the edge region of the material, wherein the axial direction of the axes of rotation of the upper ( 31 . 32 ) and lower rollers ( 30 ) is independently changeable to support the deformed material, wherein, when using the device, the roll deformation between the at least one pair of upper rollers ( 31 . 32 ) and the lower roll ( 30 ), with the side rollers ( 33 . 34 ) abut the previously deformed zones of the material from the outside of the bend to prevent the rebound phenomenon, the device preferably being used in a method comprising the steps of: i) forming a pinch edge (pp) by applying the upper roll ( 31 . 32 ) to the bending inside of the band ( 1 ); ii) setting the pinch edge (pp) to a boundary between the target deformation zone (pp) 1b . 1c ) and an adjacent area ( 1a . 1d ) of the band ( 1 ); and iii) winding the target deformation zone ( 1b . 1c ) of the band ( 1 ) around a roller surface of the upper roller ( 31 . 32 ) on the bending inside without through the lower roller ( 30 ) to be restricted from the bending outside.