Cross edge rolling

Abstract

A cross edge rolling process for increasing a thickness of a strip in longitudinal edge strips on both longitudinal sides of the strip. According to the invention, this is achieved in that firstly a step extending in the longitudinal direction of the strip is produced by means of a roll profiling process, wherein the strip is supported during the cross edge rolling process on said step against a compression force acting transversely to the strip, so that the strip is not compressed outside the longitudinal edge strip. After the edging process for increasing the thickness of the longitudinal edge strips, the strip is bent by means of a roll profiling process to form a C-profile rail.

Claims

1. A method for thickening a longitudinal edge strip of a strip made of a plastically deformable material, the method comprising: transversely compression-rolling the strip in a transverse direction so that the strip becomes narrower and at the same time the longitudinal edge strip becomes thicker, wherein the longitudinal edge strip is a section of the strip extending along a longitudinal direction of the strip at a longitudinal edge of the strip; before or simultaneously with the transversely compression-rolling, bending the strip in opposite directions along two parallel bending lines, wherein the bending lines extend in a longitudinal direction of the strip and define the longitudinal edge strip, thereby forming a step extending in the longitudinal direction of the strip; and supporting the strip at the step during the transversely compression-rolling of the longitudinal edge strip.

2. The method according to claim 1, further comprising performing the bending of the strip at the bending lines by roll profiling process.

3. The method according to claim 1, wherein the transversely compression-rolling comprises: compression-rolling the strip in a transverse compression direction by an edging roller, wherein the edging roller is arranged laterally in relation to the strip and presses against a longitudinal edge of the strip; and supporting the strip by a support roller at the step that extends parallel to the longitudinal edge of the strip, wherein the support roller supports the strip in the transverse direction (Q) of the strip against a compression force exerted by the edging roller.

4. The method according to claim 3, wherein the support roller is arranged on an upper side of the strip, and wherein an end face of the support roller supports the strip against the compression force of the edging roller at the step extending in the longitudinal direction of the strip.

5. The method according to claim 1, further comprising: bending the strip at two bending lines parallel to the longitudinal edges on both longitudinal edges of the strip; and, transversely compression-rolling both longitudinal edges of the strip to form a profile symmetrical in relation to a longitudinal center plane, wherein the longitudinal center plane is perpendicular to the transverse direction of the strip.

6. The method according to claim 1, further comprising bending the strip after the transversely compression-rolling to form a C-profile rail.

7. The method according to claim 1, wherein the bending of the strip comprises bending the strip at an inner bending line by an angle between 45 and 90, wherein the inner bending line is remote from the longitudinal edge of the strip.

8. The method according to claim 4, wherein the end face of the support roller is at an angle between 45 and 90, relative to a circumferential surface of the support roller.

9. The method according to claim 3, wherein at a compression point pressing against the longitudinal edge of the strip, a circumferential compression surface of the edging roller is at an angle between 70 and 85 to an axis of rotation of the support roller.

10. The method according to claim 3, wherein the edging roller includes a support surface that rests on the longitudinal edge strip of the strip.

11. The method according to claim 1, wherein the bending of the strip creates of the step with two bending lines and wherein the size of the bending angles at the two bending lines differs at most by 45.

12. The method according to claim 1, wherein the step has a height which corresponds to 0.5 to 1.5 times the thickness of the strip in the region of the step.

13. The method according to claim 1, wherein the transversely compression-rolling causes the longitudinal edge strip to become thicker in a region extending from the longitudinal edge to a second-closest bending line, wherein the second-closest bending line is the second bending line counted from the longitudinal edge.

Description

(1) The invention is explained in more detail below with reference to the drawing. The figures show successive stages of the method according to the invention in a simplified and schematic representation.

(2) In the drawings:

(3) FIG. 1 shows a strip in a longitudinal view at a rolling station in a first stage of producing a step;

(4) FIG. 2 shows the same strip in a second stage of producing the step;

(5) FIG. 3 shows the same strip in a first stage of a cross edge rolling process;

(6) FIG. 4 shows the same strip in a second stage of a cross edge rolling process; and

(7) FIG. 5 shows the same strip bent to form a C-profile rail.

(8) In its passage, in a plurality of stages, the C-profile rail 2 shown in FIG. 5 is produced from a strip 1, said C-profile rail having a rectangular tube cross-section with a continuous longitudinal slot 3 in a transverse center of one side. The figures show successive forming stages, wherein further forming stages (not shown) between the forming stages shown in the figures can take place or a plurality of forming stages may also be combined. The figures show the forming on one longitudinal side of the strip 1; on an opposite longitudinal side, the strip 1 is formed in the same way. The strip 1 is formed symmetrically to a plane of symmetry which is perpendicular to the originally flat cross-section of the strip 1 and extends in a transverse center of the strip 1 in the longitudinal direction thereof and is a longitudinal center plane LM. The strip 1 extends with its transverse extension in a transverse direction Q, to which the longitudinal center plane LM is perpendicular.

(9) The strip 1 basically has any length; it may consist of long pieces of a length of several meters or may even be unwound from a coil. In the exemplary embodiment, it has a flat rectangular cross-section with a thickness between 1.5 millimeters to 2.5 millimeters and is between 30 and 60 times as wide as thick. The strip 1 consists of a plastically deformable material, in particular is made of steel, of an aluminum alloy or generally of metal. An elastic deformability of the strip 1 is rather undesirable because it may impair the plastic deformation, but an elastic deformability of the strip 1 is not excluded and is in any case unavoidable to a small degree in practice.

(10) The strip 1 is guided in each forming stage between an upper roller 4 and a lower roller 5, which roll on two opposite large sides of the strip 1. In the exemplary embodiment, the upper roller 4 and the lower roller 5 are cylindrical rollers with parallel axes, which have a gap of the thickness of the strip 1 or somewhat less in order to clamp the strip 1 between the upper roller 4 and the lower roller 5 and possibly also to reduce the thickness of the strip 1. The upper roller 4 and the lower roller 5 do not have to be arranged horizontally, or one above the other.

(11) In their passage, as shown in FIG. 1, longitudinal edge strips 6 on both longitudinal sides of the strip 1 are bent in the same direction at on each side of a first or inner bending line 8, which extends parallel to longitudinal edges 9 of the strip 1, by means of first bending rollers 7 arranged laterally of the upper roller 4 and of the lower roller 5. The longitudinal edge strips 6 are bent by up to 90. In the exemplary embodiment, the longitudinal edge strips 6 of the strip 1 are bent overall by approximately 70 to 80 in a plurality of steps, of which FIG. 1 shows a final step. The first bending rollers 7 are likewise cylindrical rollers or even frustoconical rollers, the axes of which are in one plane with the axes of the upper roller 4 and of the lower roller 5. Rollers other than bending rollers 7 are not excluded by the invention.

(12) The longitudinal edge strips 6 on both sides of the strip 1 are then bent at second or outer bending lines 10 in a direction opposite to previously. The bending lines 8, 10 are represented in the figure by dot-dashed lines, which themselves are not parallel to the longitudinal edges 9 but correspond in each case to the bisector of the bending angle. That is to say, the bending lines 8, 10 extend perpendicular to the dot-dashed lines and perpendicular to the plane of representation. The outer bending lines 10 extend parallel to the inner bending lines 8 and parallel to the longitudinal edges 9 of the strip 1 at a distance of approximately the thickness of the strip 1 outside the inner bending lines 8i.e., the outer bending lines 10 are closer to the longitudinal edges 9 than are the inner bending lines 8. The bending process of the longitudinal edge strips 6 at the outer bending lines 10 in the direction opposite to previously preferably likewise takes place in a plurality of stages, of which FIG. 2 shows a last stage, until the longitudinal edge strips 6 between the outer bending lines 10 and the longitudinal edges 9 extend parallel to or at an acute angle of approximately 10 to 20 to the strip 1 in the exemplary embodiment between the inner bending lines 8. In the exemplary embodiment, the longitudinal edge strips 6 at the outer bending lines 10 are bent back less far than they are bent at the inner bending lines 8 so that the longitudinal edge strips 6 extend obliquely in the direction in which they are also bent at the inner bending lines 8.

(13) As a result of the double bending at the two bending lines 8, 10 in opposite directions, a step 11 is formed which is continuously parallel to the longitudinal edges 9 of the strip 1 in the longitudinal direction of the strip 1. As a result of the bending of the strip 1 at the inner bending lines 8 by approximately 70 to 80 in the exemplary embodiment, a portion of the strip 1 between the inner and the outer bending line 8, 10 is at an angle of approximately 100 to 110 to the central portion of the strip 1 between the inner bending lines 8. In other words, the size of the bending angles at the two bending lines 8, 10 differs by approximately 10 to 20. In this way, the step 11 has approximately a parallel offset. A height H of the step 11 corresponds approximately to the thickness D of the strip 1 in the region of the step 11.

(14) For bending at the outer bending lines 10, the longitudinal edge strips 6 in the exemplary embodiment are guided between two second bending rollers 12 which in the longitudinal edge strips 6 rest on the upper and lower sides of the strip 1. The second bending rollers 12 are likewise cylindrical or frustoconical rollers, the axes of which are in one plane perpendicular to the passage plane of the strip 1 with the axes of the upper roller 4 and of the lower roller 5.

(15) The bending of the strip 1 at the bending lines 8, 10 is a roll profiling process, which is also referred to as a roll forming process.

(16) Instead of the separate first and second bending rollers 7, 12, the double bending may also take place by correspondingly shaped upper and lower rollers (not shown) which extend into the region of the longitudinal edge strip 6 and there have a stepped shape corresponding to the step 11. In this way, the two bending lines 8, 10 can in particular also be produced simultaneously, wherein this can in turn be distributed over several forming stages with upper and lower rollers arranged one behind the other. However, the double bending, i.e., the creation of the step 11, preferably takes place in a single stage.

(17) After the bending process of the strip 1 at the inner bending lines 8 in the one direction and at the outer bending lines 10 in the opposite direction, the strip 1 is compression-rolled in a transverse compression direction QS by means of laterally arranged edging rollers 13, which press transversely to the strip 1 against the longitudinal edges 9 thereof. The axes of the edging rollers 13 are perpendicular to the axis of the upper roller 4. Alternatively, the cross edge rolling process can also already take place simultaneously with the bending process of the step 11, in particular if the step 11 is produced by correspondingly shaped upper and lower rollers (not shown). In this case, an edging roller projects between the upper roller and the lower roller. For greater clarity, however, the cross edge rolling process is shown here as a separate, subsequent stage. The edging rollers 13 have a frustoconical or cylindrical compression section 14 which rolls on the longitudinal edges 9 of the strip 1, and a disk-shaped support section 15 which rests on the upper side of the longitudinal edge strips 6 of the strip 1. In this case, the upper side is the side in which the longitudinal edge strips 6 are offset relative to the central portion of the strip 1 between the inner bending lines 8 by the double bending in the opposite directionsIn other words, the side toward which the steps 11 increase. The support sections 15 of the edging rollers 13 prevent the longitudinal edge strips 6 during the edging process of the strip 1 in the transverse direction Q from being bent back in the direction opposite to previously during the bending. Perforated-disk-shaped faces of the support sections 15 resting on the longitudinal edge strips 6 may also be considered as support faces 16. Differing from the exemplary embodiment, support rollers that are separate from the edging rollers 13 or even stationary support faces (not shown) may be provided.

(18) During the cross edge rolling process, the steps 11 of the strip 1 on the upper side thereof between the inner and the outer bending lines 8, 10 rest against end faces 17 of the upper roller 4, which forms a support roller 18, which supports the strip 1 or the longitudinal edge strips 6 of the strip 1 on the step 11, i.e., in the portion extending in the longitudinal direction of the strip 1 between the inner and the outer bending lines 8, 10, in the transverse direction Q of the strip 1 against a compression force exerted by the edging rollers 13 transversely to the strip 1 on the longitudinal edges 9 of the strip 1. As a result of the support at the step 11, only the longitudinal edge strips 6 of the strip 1 are compression-rolled, whereby they become thicker and narrower in the transverse direction Q of the strip 1. The end faces 17 of the upper roller 4 forming the support roller 18 may be flat radial surfaces or conical or frustoconical, i.e., they have an angle between 45 and 90 to a circumferential surface of the support roller 18.

(19) At a compression point, a circumferential surface of the frustoconical compression section 14 of the edging rollers 13 has an angle between approximately 85 and 70 to the axis of the support roller 18 (FIG. 3). The circumferential surface of the compression section 14 of the edging rollers 13 may also be considered as a compression surface 19. The compression point is the point at which the compression surface 19 or the edging rollers 13 rest against the longitudinal edge 9 of the strip 1 during the edging process. The transverse compression direction QS, in which compression takes place in the first stage of the cross edge rolling process, thus does not extend perfectly perpendicularly to the longitudinal center plane LM.

(20) In the last compression stage, shown in FIG. 4, the lower roller 5 is so wide that the strip 1, including the longitudinal edge strips 6 thereof, rests on it. As a result, a flat large side of the strip 1 is achieved, which in the exemplary embodiment has a production-related groove extending in the longitudinal direction of the strip 1, with a rounded cross-section in the region of the bending lines 8, 10. The flat large side of the strip 1 following the cross edge rolling process forms an outer side on the C-profile rail 2 shown in FIG. 5. In the stage of the cross edge rolling process shown in FIG. 4, the transverse compression direction QS is perpendicular to the longitudinal center plane LM since the compression surface 19 is cylindrical here. As can be seen clearly in FIG. 4, the longitudinal edge strip 6 becomes thicker up to the inner bending line 8 and even somewhat beyond it. The cross edge rolling process thus extends up to the region of the step 11.

(21) FIGS. 3 and 4 show a first and a second cross edge rolling stage, wherein the longitudinal edge strips 6 can be transversely compression-rolled in further stages (not shown) so that the forming in the individual stages is smaller. The strip 1 can be cold or hot compression-rolled.

(22) After the cross edge rolling process of the longitudinal edge strips 6 of the strip 1, the strip 1 is bent in a plurality of stages (not shown) to form the C-profile rail 2 shown in FIG. 5. The bending process takes place in a pass by means of a roll profiling process (roll forming) as in the bending process of the step 11.

LIST OF REFERENCE SIGNS

(23) Cross Edge Rolling

(24) 1 Strip 2 C-profile rail 3 Longitudinal slot 4 Upper roller 5 Lower roller 6 Longitudinal edge strip 7 First bending roller 8 Inner bending line 9 Longitudinal edge 10 Outer bending line 11 Step 12 Second bending roller 13 Edging roller 14 Compression section 15 Support section 16 Support face 17 End face 18 Support roller 19 Compression face D Thickness of the strip 1 in the region of the step 11 H Height of the step 11 LM Longitudinal center plane Q Transverse direction QS Transverse compression direction