SCOPE OF INVENTION
The invention relates to a method for forming a plane sheet bar section to a profile with a central, plane bottom part and with a varying width and upright sides with or without associated flanges along the length of the profile and relates to a roll-forming machine comprising two rows of forming stations which can move laterally and rotatably for forming such a profile.
BACKGROUND OF THE INVENTION
Roll-forming machines for such a roll-forming with a variable profile form are known from a plurality of publications.
Examples of such are DE 100 11 755 A1 and EP 1 676 654 B1. The equipment and procedure for obtaining plane products are described in DE 20 2009 007 527 U1 and SE 100 12 28 A1. Other patent publications also describe arrangements for making the bottom part plane with the aid of arrangements which are separate from the forming stations. Equipment is also known with which a plane product is bent in separate stations after the roll-forming process itself. See patent EP 1 439 920 B1 and EP 1 877 205 B1.
THE PURPOSE OF THE INVENTION AND A SHORT DESCRIPTION OF THE INVENTION
It is a purpose of the invention to reduce or entirely avoid that the roll-forming process gives the formed product a central bottom part which is not plane in the longitudinal direction. This is brought about in principle in that, directly after or in conjunction with a complete folding up, the folded-up sides are clamped over the entire height of the sides with a constant force so that the distribution of stretching in the clamped sides is corrected and that a plane product with a variable width is obtained when the roll-forming is finished. The invention is defined by the claims.
SHORT DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the forming steps for a profile with upright sides during the roll-forming from a plane bar section.
FIG. 2 shows forming steps for a profile with upright sides with associated flanges during the roll-forming from a plane bar section.
FIG. 3 shows an example of the finished product with upright sides and associated flanges. The figure shows a straight product with a parallel bottom part.
FIG. 4 shows examples of a roll-forming machine with paired forming stations for forming a profile with two upright sides and associated flanges.
FIG. 5 is a transverse view showing a basic example of a forming station on two sides for forming a profile with two upright sides. They can shift laterally and rotatably so that profiles with a varying width can be formed.
The transverse view is indicated by arrows 5-5 in FIG. 6.
FIG. 6 is a top view which shows a basic example of a forming station on two sides for forming a profile with two upright sides. They can shift laterally and rotatably so that profiles with a varying width can be formed.
The top view is indicated by arrows 6-6 in FIG. 5.
FIG. 7 shows by way of example a plane bar section for a product which has a convex bottom part viewed from above. The width varies along the length and is widest in the middle.
FIG. 8 is a longitudinal view of a finished product with a convex bottom part formed without using the invention. The desired, plane product is bent up viewed from the side.
FIG. 9 shows by way of example a plane bar section for a product which has a concave bottom part viewed from above. The width varies along the length and is narrowest in the middle.
FIG. 10 is a longitudinal view of a finished product with a concave bottom part formed without using the invention. The desired, plane product is bent down viewed from the side.
FIG. 11 shows an example of a roll-forming machine from above where the next to the last forming stations on each side are provided with an arrangement with clamping rollers for the upright sides in the formed profile.
FIG. 12 shows an example of a forming process from a plane bar section to the finished product in a roll-forming machine where the next to the last forming stations on each side are provided with an arrangement with clamping rollers for the upright sides in the formed profile.
FIG. 13 shows a view of a forming station with an example of an arrangement on each side where the clamping rollers create a clamping with a constant pressure on the upright sides with the aid of pressure cylinders and a lever mechanism.
FIG. 14 shows a view of a forming station with an arrangement where the clamping rollers are active on the outside of the profile.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows by way of example the forming steps in the roll-forming of a plane bar section 11 to a profile 12 with a plane bottom and two upright sides 22, 23. Roller forming includes a successive folding up of the upright sides 22, 23. The actual profile in the figures has bent corners 26, 27. In the example the last and the next to the last forming step are similar. This is often the case where experience has shown that the profile then receives a better profile form. For economic reasons this is not done at times, which means that the shape in the last and the next to the last station are then different.
FIG. 2 shows as a second example the forming steps in the roll-forming of a plane bar section 11 to a profile 13 with the plane bottom 21 and two upright sides 22, 23 with associated flanges 24, 25. Roll-forming includes a successive folding up of the upright sides 22, 23. The corners bent in toward the bottom part are marked with 26, 27. In the example the last and the next to the last forming step are similar. This is often the case where experience has shown that the profile then receives a better profile form. For economic reasons this is not done at times, which means that the shape in the last and the next to the last station are then different.
FIG. 3 shows a finished product with profile 13, which has in this case a parallel bottom part 21 where the corners 26, 27 were formed in straight lines.
FIG. 4 shows the forming process in a roll-forming machine. It is constructed by a number of stand parts 81, 82 with forming stations 32, 33 on each side for forming the two sides from the current profile form 13. Forming rollers 41, (43 hidden) and 42, 44 are present in all forming stations.
FIGS. 5 and 6 show the basic forming for both sides in the paired forming station 32, 33. It comprises two pairs of roller forming rollers 41, 43 and 42, 44 which hold the half-formed bar section 11 between them with a uniform sheet slot. The forming station comprises two stand units 81, 82 and the forming rollers 41, 43 and 42, 44 are mounted in them. The stand units have vertical pins 93, 94 which carry the stand units and are mounted in a base, which is not shown, so that the stand units become rotatable around vertical axes I and II. The pins 93, 94 can be shifted sideways in the base, which is indicated by the arrows 61, 62.
The arrows 71, 72 indicate how the forming rollers can be rotated. AN movements are motor-driven and computer-controlled but the drive arrangements are not shown. Therefore, the forming rollers 41, 42 and 43, 44 can be moved sideways 61, 62 during the roller forming process and they can moreover be rotated around the axles I and II as indicated by the arrows 71, 72.
FIG. 7 shows a bar section 11 which has a convex form where the lines from which the corners 26, 27 are to be formed are marked with dotted lines which were given the same designation as the corners. Such a bar section with a convex form provided for forming profile 12 (FIG. 1) tends to impart a curved-up shape to the finished product viewed from the side as shown in FIG. 8. This described phenomenon also applies if the product is based on profile form 13 (FIG. 2) with flanges 24, 25 on the upright sides 22, 23.
FIG. 9 shows a bar section 11 which has instead a concave form. Such a bar section with a concave form provided for forming profile 12 (FIG. 1) tends to impart a curved-down shape to the finished product viewed from the side which is shown in FIG. 10. This described phenomenon also applies if the product is based on profile form 13 (FIG. 2) with flanges 24, 25 on the upright sides 22, 23.
In order to prevent that the finished product is bent in the vertical plane, i.e. that its bottom 21 (FIGS. 1 and 2) is not plane in the longitudinal direction, as is shown in FIGS. 8 and 10, this can be counteracted according to the invention in that in one of the last forming stations an arrangement for clamping the upright sides 22, 23 with a constant force is installed. In the case of a convex or concave shape of the bottom part the plate surface does not agree with the bent-up, upright sides. Clamping the upright sides 22, 23 directly after or in conjunction with a complete bending up over the entire height of the sides with a constant force 55, 56 can bring about a redistribution of the stretching in the forming so that the tendency not to be plane is reduced or entirely eliminated. The clamping force 55, 56 creates a three-axis tensioning state in the material, which imparts a plastic state to the upright sides 22, 23 so that the stretchings can be redistributed.
FIGS. 11 and 12 show an example of a roll-forming machine 30 with 6 units of customary, paired forming stations 32, 33 for the successive bending up of the upright sides 22, 23. The next to the last stations were provided with arrangements 51, 52 for clamping with a constant force the upright sides 22, 23. The arrangement 51, 52 in the example comprises pressure cylinders 57, 58 which bring it about that the clamping rollers 45, 46 clamp the upright edges 22, 23 (FIGS. 1 and 2). The forming rollers 41, 42 constitute holding-up tools. FIG. 12 shows the machine and the entire forming process for example with profile 13 formed from the plane bar section 11 (FIG. 2).
The machine has the same basic appearance even if a product without flanges is formed (FIG. 1). The forming stations with clamping arrangements 51, 52 are suitably placed next to the last in the machine but other placings at the end of the machine can also occur. It is possible to provide one of the three last forming stations with clamping arrangement 51. 52.
FIG. 13 shows a view of an example of clamping arrangement 51, 52. The desired change of the plate's distribution of stretching in the upright sides 22, 23 for profile 13 according to FIG. 2 is brought about by clamping rollers 45, 46 which press 55, 56 against the upright sides 22, 23 with a constant force. The forming rollers 41, 42 constitute holding-up tools. The contact surfaces of forming rollers 41, 42 and clamping rollers 45, 46 are parallel with the upright sides 22, 23. The arrangement in the example consists of pressure cylinders 57, 58 which create pressure forces 59, 60 which create pressure forces 55, 56 on the clamping rollers 45, 46 with lever arms 95, 96 around turning points 53, 54. The pressure cylinders 57, 58 used can be either hydraulic, pneumatic or electrical.
FIG. 14 shows a basic view of an example of a clamping arrangement in which clamping rollers 45, 46 are active from the outside of the profile 13, which imparts constant pressure forces 55, 56 against the outside of the upright sides 22, 23. Forming rollers 41, 42 constitute holding-up tools. The contact surfaces of the forming rollers 41, 42 and clamping rollers 45, 46 are parallel with the upright sides 22, 23.
Patent Application
20190210084
