SHORT DESCRIPTION OF THE INVENTION AND PRIOR ART

The invention relates to a rolling mill machine for longitudinal profile bending of thin plate, e.g. for manu¬ facturing of building plate of trapezoidal section, comprised of a number of shaping stations with individual free-rolling work rolls arranged in such a pattern that they form rows both across the direction of the movement of the strip and along the direction of the movement of the strip.

Such machines belong to the prior art of, for example, DE-OS 2,941,180 and WO 87/04375. The rolls there are arranged in straight rows across the direction of the movement of the strip. Such an embodiment should function satisfactorily if the machine is constructed with a sufficient number of shar¬ ing stations and with a great distance between the shaping stations.

According to the present invention in at least one or more of the shaping stations the work rolls are arranged so that the middle roll or rolls in a transverse row begins to form the strip before the outer rolls. The invention has thus been given the characterization presented in the claims. It appears especially important that a number of the first shaping stations have their rolls arranged in thiε manner.

By means of the invention it is found possible to bct_h reduce the total length of the machine and the number of shaping stations and to make the machine more compact. In addition, the final product produced in a machine according to this invention will be of higher quality with view to its shape and the machine can be used to shape cut strip. Through angling of the work rolls in the manner giver, in the sub-claims and through use of a calibration station as presented in the sub-claims, an even more improved shape accuracy in the final product is obtained.

If in addition support tables are used as defined ir. the claims the total length of the machine and the number c: shaping stations can be further reduced.

SHORT DESCRIPTION OF THE DRAWINGS

Fig. 1 is a side elevation through a roll shaping machin according to the invention, where the section is taken along line 1-1 in Fig. 2. Fig. 2 is a plan elevation of the machine shown in Fie. 1.

Fig. 3 is a fragmentary section taken along the line 3-3 in Figs. 1 and 2.

Fig. 4 is an example of a plan for placement of the work rolls in a machine of the type shown in Figs. 1-3. DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

The rolling machine shown in the figures has a housing, the chief parts of which are made up of an upper 12 and lower 13 longitudinal beam on one side of the machine and a corresponding upper 14 and lower 15 beam on the other side. A number of posts 18 support and hold together the upper and lower beams 12 and 13, 14 and 15, respectively, on the respec tive sides, and the upper beams 12, 14 are held together with a number of cross-tie beams as are the lower ones 13, 15. The cross-tie beams have been shown in Figs. 1 and 2 and indicated by 16 and 17.

Within the housing a number of shaping stations have been constructed, whereof the first three 20-22 and the last two 23, 24 are shown. The midsection of the machine with, for example, 8 shaping stations has been cut away in Figs. 1 and 2. A calibration station 25 with cylindrical full-width rolls 110, 111 is installed following the final shaping station. Between the shaping stations and as first and lasr station there are drive stations 26-31. The drive stations 26-31 are all in principle alike and reference notations have in Figs. 1 and 2 been indicated only on the first drive station 26. The drive stations 26-31 all have a lower cylindrical drive roll 32, which is supplied with a rubber coating to increase the friction. The drive rolls 32 are driven in tandem by a motor not shown via a drive chain 33 which rotates a number of sprocket wheels 34, which share a shaft with smaller sprocket wheels 35, which via short chains 36 rotates the drive wheels 32. The chains

33, 36 shown in Fig. 2 by the broken lines are placed next to the beams 14, 15, but in order not to make Fig. 2 unclear, the drive chains and the sprocket wheels have been left out of Fig. 2. The drive stations all have an upper box beam 37 in which there is a row of free-rolling counter rolls 38 which run against the drive rolls 32.

Between the first six stations there are support tables 41-46 which are secured between the upper longitudinal beams 12, 14. The shaping stations 20-24 are in principle all similar to each other except that the positions of the freely rotat¬ ing rolls vary as shall be described later with reference to Fig. 4.

Parts of the shaping station 20 are shown in more detail in Fig. 3. It is comprised of an upper and a lower horizontal transverse, box beam 50 and 51 respectively with square cross-section.

The box beams 50, 51, have flanges 53, 54 and 55, 56 by which they are secured in vertical strips 59, 60, which in turn are fastened in the beams 14, 15 and 12, 13, respect¬ ively, of the housing.

On the beam 51 seven brackets are mounted with screws, where one bracket 76 is seen whole and two brackets 77, 7C are cut. The remaining brackets are cut away. The brackets have two wings 79, 80 as is indicated on bracket 76 and a shaft 81 extends through holes in the wings 79, 80, A roll 82 is mounted on the shaft 81 with double bearings at a distance from each other so that it is free-rolling but is prevented from turning in the direction of the plane of the paper.

On the beam 50 there is a row with six brackets 84 with rolls 85 attached, of which only one bracket and one roll are seen in Fig. 3.

The rolls 85 are placed laterally between the rolls 81 and the strip 91, which is to be formed by the so-called free-forming, i.e. it is formed without its being squeezed between two opposite rolls as with conventional shaping.

At the very outside of both sides of the rotatable beam 50 there are two edge rolls 86, 87 similarly mounted with double bearings on fixed shafts 88 secured in brackets 89.

A cylindrical part 92 of each edge roll 86, 87 is direct- ly in front of the corresponding exterior of rolls 82 in the row of rolls of the beam 51 and the strip is guided up there¬ between, the outer edges of the strip being formed by the outer cut-off conical sections 93 of the edge roll.

As is evident from Fig. 1 all the rolls of the lower beam (i.e. rolls 85 and beam 50 in Fig. 3) which are in operative position touch a horizontal plane 106, designated by broken lines, and this plane 106 touches also all the drive rolls 32 of the drive stations 26-31 and their counter rolls 38. The plane 106 defines an entry plane for the flat strip and a delivery plane for the finished, profiled strip, i.e. a plane in which the lower profile flanges lie during the whole profile bending. The entry table and the delivery table in this plan can be made separate from the machine in general and are not shown on the figures. The support stands 41-46 also lie in this plane 106.

The drive rolls 32 and the counter rolls 38 of the drive stations 26-31 thus clamps the lower flanges of the strip, and the clamping force is adjustable with springs. The adjustment of the bearing pressure is trivial and is nor shown. One does not need to have counter rolls in each lower flange, but can have, by way of example, four counter rolls, but six work rolls which give six lower flanges.

Fig. 4 is a simplified example of a plan for placing the work rolls in a machine of the type shown in Figs. 1-3. The work rolls shown in Fig. 4 are indicated as crosses which give the plane of symmetry of the roll transverse to its rotational shaft and the rotating shaft of the work roll. As is evident from Fig. 4 the work rolls in each shaping station are placed in transverse rows. Only the final shaping station 24 has the work rolls placed in a straight line. The remainder of the shaping stations have their rolls placed in arc-formed of transverse rows and the

different rows of the shaping stations form longitudinal rows of which rows 118, 119, 120 are shown. Each row 118, 119, 120 shapes an upper flange and the strip takes on by means of this configuration of work rolls six upper flanges. Reference number 112 indicates the center line of the machine and the vertical plane of symmetry and placement of the rolls is shown only on one side of this plane, since the rolls is symmetrically positioned. The figure shows in plan elevation the placement of the rolls 82 in Fig. 3 in the different shaping stations. In addition to the shaping sta¬ tions 20-24 shown in Figs. 1 and 2, five shaping stations 113-117, which lie in between, are shown. In Fig. 4 are shown, therefore, ten shaping stations while the machine illustrated in Figs. 1-3 is defined as having thirteen shap- ing stations.

It is best to have the rolls of the first shaping sta¬ tion be parallel to the vertical plane of symmetry 112, i.e. their shafts should be at right angles to this plane of symmetry 112, which at the same time shows the strips direc- tion of feed as upward in Fig. 4. In the longitudinal rows, the rows of work rolls formed by the shaping stations 21, 22, 113, 114 have their rotating shafts in successively decreasing angles to the plane 112. This angle is illust¬ rated as angle α in the outer roll in the shaping station 114. Thereafter the angle o. is constant between the shaping stations 114 and 115 with the angle thereafter successively increasing and becoming almost a right angle in the final shaping station 24. It should be pointed out that Fig. 4 is not to scale but arc and angles have been exaggerated and that the number of shaping stations in which the rotating shafts of the work rolls in the respective longitudinal rows of work rolls are parallel is normally more than the two 114, 115 which are shown. In these shaping stations the rolls lie along straight lines in every longitudinal row. kε shown, three or four shaping stations are optimally needed in the bends in the beginning and end.

As a practical example it can be said that for a strip with 11 upper flanges, an entry band width of 1250 mm, a finished width of 1000 mm, and a section height of 20 mm, the angle α was at its very least 89.2°. In the same example within one and the same shaping station, a roll 82 in an inner row 118 was placed at most 9.5 mm in front of the corresponding roll in an outermost row 120.

The work rolls should be directed so that their symmetr lies along the line which runs through the center of the nearest previous roll. The arc in every shaping station car- best be such that the rotating shaft of a roll runs through or behind the center of the nearest inside roll, as seen in relation to the direction of the movement of the strip. Normally the middle roll or rolls in the shaping statio which has the greatest arc lie 0.5 to 3 cm in front of the outermost rolls.

In order to achieve a simpler assembly, as a compromise one can place the rolls in wedge-shaped transverse rows instead of arcs. Even in such a case the middle rolls will begin to form the strip before the outer rolls.

One can presumably obtain a satisfactory result if one uses only a few axial positions and a few angle positions, e.g. three or four axial positions and three or four angle positions, and chooses from among these standardized posi¬ tions those positions which best agree with the desired position. One can then use a few forms , which should make easier the mounting of the rolls. The chief point is that the middle roll or rolls begin to shape the strip first. It is also possible that one does not need to have the wedge cr arc form on more than a number of the first shaping stations e.g. the first three, four or five, in order to obtain a satisfactory result. When the strip reaches a section heigh of over 0.5 or 1 cm, exact position and angle are no longer as critical.

If the counter roll 38 used in the drive station is several millimeters narrower than the corresponding work rolls, then the assembly of the work rolls is made easier,

since the placement of the counter rolls is then not criti¬ cal. It is also an advantage if the counter rolls 38 can be turned individually in the same manner as the work rolls, since one can then possibly urge the strip sideways by turn- ing the counter rolls, should the strip tend to deviate from its correct path due to minor errors in the positional angles of the work rolls. One can then mount all work rolls before delivery of the machine and later, following set-up of the machine, only do a final adjustment of several of the counter rolls 38 of the drive stations.

The conventional manner is to cut the strip into desired lengths after shaping in order not to get wedge-shaped strips The rolling mill machine described allows instead for the strip to be cut into desired lengths before shaping without a problem with wedge shape.