EP0274722B1 - Straightening machine for plate and strips - Google Patents

Abstract

A leveling machine for steel sheet and strip includes changing cartridges between sets of leveler rolls including support rollers and adjustable crossheads. Each changing cartridge includes three cartridge portions which are connected to each other by means of two intermediate joints. The middle cartridge portion is supported on the corresponding crossheads by means of two spaced-apart rigid supports, so that only the outer cartridge portions can be limited in their pivoting positions by means of adjusting wedges or the like and, for compensating sagging of the crossheads, the leveler rolls must only be subjected to a prebending force in the regions away from the middle cartridge portion.

Description

The invention relates to a straightening machine for sheets and strips, in particular for cold-rolled sheets and strips, according to the preamble of claim 1, and is therefore based on a prior art known from practice, the so-called "tilting yoke adjustment". Straightening machines of this type, as are known from EP-A-0 005 760, have upper and lower transverse yokes or crossheads and exchangeable cassettes which are divided in the central vertical transverse plane of the straightening rollers and are connected to one another by articulated connections such that the cross-head and cassette parts together with the groups of support rollers for the straightening rollers that they support can be easily tilted or turned into a V-shape under no-load conditions. Under the straightening force, the crossheads and interchangeable cassettes should bend so far that the preset V-shape disappears, the groups of support rollers are axially aligned and, accordingly, the straightening rollers are straight. This is to compensate for the deflection of the crossheads. It goes without saying that the crossheads or at least the upper crosshead as a whole can be adjusted obliquely in the feed direction of the straightening goods by means of two pairs of adjusting devices which are supported on stands, in order, as is known, to decrease the immersion depth of the offset straightening rollers for hyperextension distribution from the infeed side of the straightening goods to the outlet side adjust.

The bending behavior of the divided crossheads of known sheet metal straightening machines with the tilting yoke described is determined in that the crossheads are to be understood as supports with two supports on which the bending force acts at least initially in the central plane of symmetry until the straightening rollers are straight due to the deflection of the crossheads. With a given bending stiffness of the crossheads, the deflection is thus optimal. However, the size of the preset V-shape of the divided crossheads also depends on the degree of deflection. Furthermore, since the straightening rollers should now bear against the groups of support rollers, which are likewise V-shaped, under idling conditions, the straightening rollers must also be pre-bent in a V-shape by forces acting on their ends. Since the extent of the straightening roller pre-bending due to the strong kink position and the groups of support rollers to the right and left of the central vertical transverse plane of the crossheads must be considerable, the straightening rollers - until they are bent under the straightening force - are subjected to considerable bending stress.

The invention has for its object to improve the known "Kippjochprinzip" in a straightening machine for sheets and strips in such a way that the straightening rollers have to be less pre-bent before the straightening force occurs, i. H. the straightening rollers are treated more gently.

This object is achieved according to the invention from the characterizing features of claim 1. According to this, the crossheads are made in one piece in a conventional manner, the interchangeable cassettes no longer being made in two parts, but instead being made in three parts by two intermediate joints each with a central part which is divided into two Spaced rigid supports supported on the associated crosshead. First of all, this leads to improved bending behavior of the one-piece crossheads, which can thus be carried out more easily.

To protect the straightening rollers, however, it is more important that the preset buckling of two groups of support rollers is only present in the area of the two articulated and thus swiveling outer side parts of the non-rigid exchangeable cassette, the swivel position of which limits the directional force relative to the associated crosshead by an adjusting device in each case is. The consequence of this is that the straightening rollers are no longer to be subjected to a pre-bend in the central region, but only at their ends, which ensures contact between the ends of the straightening rollers and the outer groups of back-up rollers even when idling.

The actuating devices, which represent limit stops to a certain extent, consist expediently of adjusting wedges which extend transversely to the straightening rollers and which, in any adjustment position, extend over the length of the cassette, as seen in the direction of advance of the straightened material, the cassettes being counter-tensioned by tension members attached to the associated crosshead the rigid supports and the adjustment wedges are pressed on. These prestressed tension members represent a kind of balancing, at least for the upper cassette, in that not only the middle part is pressed against the two rigid supports on the crosshead, but also the outer side parts are pressed against the adjustment wedges in their upward pivoting position before straightening under idle conditions . Although the lower cassette, due to its own weight, would rest with the middle part on the supports on the cross-head side as well as with the side parts that fell away in a downward inclined position on the adjustment wedges, To stabilize the conditions, the prestressed tension members fixed on the associated crosshead are also recommended.

So that the straightening rollers already under idle conditions, i. H. diverging pairs of upper and lower side parts, along with support rollers, also rest on the outer support rollers, thereby avoiding blows when the straightening material enters the roller arrangement. According to claim 3, the "Double Chock Bending" system known from rolling mill construction is used in rolling mill construction applied, d. H. the bearing housings are under bending moments which the upper straightening rollers at their ends upwards and the lower straightening rollers at their ends downwards, i. H. bend against the recessed outer support rollers carried by the diverging side part pairs. The bending moments are generated by internal second preloaded tension members, which are connected to the bearing housings in a tensile manner, and by external preloaded pressure members, so that a pair of forces acts on each bearing housing, which bends the straightening rollers at the ends as described.

Since the bearing housing of the straightening rollers and the straightening rollers themselves are fixed to the side parts of the cassette by the pretensioned second tension members on the cassette side, since these second tension members are connected to the bearing housings in a tensile manner, the cassette together with the support rollers and the associated straightening rollers constitute a coherent structural unit which can be removed axially for changing the straightening rollers. Thus, exchangeable cassettes are created, which can be removed together with the associated straightening rollers, for which purpose, according to claim 4, the tensile connections between the transversely tensioned tension members and the box-shaped cassettes can be released, as described in the drawing description is explained.

Fig. 1

einen senkrechten Querschnitt quer zur Vorschubrichtung des Richtgutes, die Kassette teilweise in Frontansicht,

Fig. 2

einen waagerechten Teilschnitt nach der Linie II-II in Fig. 1 zur Darstellung der Gelenkverbindungen,

Fig. 3

eine Einzelheit im Schnitt nach der Linie III-III in Fig. 1, und

Fig. 4

eine schematische Darstellung der dreiteiligen unstarren Kassette vor und während des Richtens.

In the drawing, an embodiment of a cold plate leveler according to the invention is shown, namely show

Fig. 1

a vertical cross section transverse to the direction of advance of the material to be straightened, the cassette partly in front view,

Fig. 2

2 shows a horizontal partial section along the line II-II in FIG. 1 to show the articulated connections,

Fig. 3

a detail in section along the line III-III in Fig. 1, and

Fig. 4

a schematic representation of the three-part rigid cassette before and during straightening.

The main components of the straightening machine partially shown in FIG. 1 are two pairs of stand-like frames 1, of which only the outlet-side frame can be seen in FIG. 1 when the direction of advance of the straightening good runs in the viewing direction. Extending between the frame parts are an upper and a not shown lower rigid crosshead 2, on which the straightening rollers 3, which are offset in the feed direction and are supported in bearing housings 4, are ultimately supported. The straightening rolls 3 are driven in a manner not shown via the pins 5 on the left, so that the removal side for changing the rolls is on the right in the drawing. The crossheads 2 can be adjusted up and down by four adjusting devices 6 in order to influence the relative position of the upper and lower straightening rollers 3 offset from one another transversely to the direction of advance of the straightening material. To set the overstretching distribution, it is known that the crossheads 2 and thus the straightening rollers 3 are set on the inlet side to a larger overstretching amount than on the outlet side, ie the crossheads 2 are set to be somewhat divergent in the feed direction.

Because of the symmetry of the straightening process, it is advisable to also assign four adjustment devices 6 to the lower crosshead 2, which is not shown, but this is not absolutely necessary.

Further details of the cold plate straightening machine shown in FIG. 1 are only explained in relation to the upper part of the machine, but they also apply in the same way to the identically designed lower part.

What is new is the arrangement of an rigid, box-shaped cassette 7 between the crosshead 2 and the straightening rollers 3, which extends over the entire length and width of the crosshead 2 and consists of a central part 7a and two side parts 7b, 7c, which are provided via intermediate joints 8, 9 are connected to the central part 7a, which is highlighted by a hatching on the edge, so as to be pivotable in the direction of the directional force that occurs. As can be seen from the horizontal partial section according to FIG. 2, the hinge pins 8a and 9a extend horizontally and connect overlapping projecting tabs of the cassette parts 7a, 7b and 7c. The hinge pins 8a, 9a are otherwise fixed by upper and lower bolts 10. The inlet-side joint connections 8, 9 shown in FIGS. 1 and 2 are also provided at the outlet-side end of the rigid cassette 7, since the hinge pins 8a, 9a are made continuously up to the outlet-side end.

The bearing blocks 12 for a group of support rollers 13 are supported by the central part 7a, each supporting a straightening roller 3. The side part 7b carries bearing blocks 14 for two further support rollers 15 for each straightening roller 3, and the side part 7a carries bearing blocks 16 for two further support rollers 17. The straightening machine thus comprises three groups of support rollers 13, 15 and 17, of which the outer groups 15 and 17 can be adjusted independently of the central group of support rollers 13 by the articulated connection of the side parts 7b, 7c to the central part 7a.

In the exemplary embodiment, all support rollers 13, 15, 17 are arranged in the vertical axis plane of the straightening rollers 3. This requires that the chocks 4 of the straightening rollers are fixed in position in the horizontal plane, for example in that adjacent bearing housings 4 abut one another. However, it is also conceivable and state of the art if each straightening roller is supported in a saddle-like manner by means of a V-shaped arrangement of support rollers and is thus fixed in the horizontal plane.

The middle part 7a is supported in the region of its ends symmetrically to the central transverse plane Q of the rigid crosshead 2 and the straightening rollers 3 via two rigid supports 20 which are arranged at a relatively large distance from one another and which distribute the straightening force transmitted by the support rollers 13 in a relatively broad distribution into the crosshead 2 transfer, which has a favorable influence on the deflection of the crosshead. Rigid webs 2a of crosshead 2 are expediently assigned to rigid supports 20 in their vertical planes.

Each outer side part 7b, 7c of the non-rigid cassette 7 is assigned in the region of the outermost support rollers 15, 17 an adjusting device 21 or 22 which limits the pivoting position of the side part with respect to the crosshead 2. In the exemplary embodiment, the adjusting devices consist of adjusting wedges 21a, 22a extending transversely to the leveling rollers 3, which in each adjustment position extend over the length of the cassette 7 - seen in the direction of advance of the leveling material - and are supported on counter wedges 21b, 22b fixed in the crosshead 2.

The cassette 7 is pressed against the rigid supports 20 and the adjusting wedges 21a, 22a by prestressed first tension members 23, 24 and 25 which are fixed to the crosshead 2. This is imperative for the upper cassette 7 for reasons of balancing, but is also provided for the lower cassette for reasons of stabilization, for the following reason as far as the outer elastic tension members 24 and 25 are concerned:
In Fig. 1, namely, the cassette 7 is shown in the straight stretched position, which it is supposed to take under consideration of the deflection of the crosshead 2 under the directional force. Without this deflection, i.e. under no-load conditions, the rigid supports 20 for the middle part 7a are set somewhat lower (and somewhat higher for the lower part of the machine), so that the side parts 7b and 7c are pivoted out on the adjusting wedges 21a , 22a. This is caused by the elastic tension members 24 and 25. FIG. 4 shows, in solid lines, schematically the bending position of the side parts 7b and 7c relative to the middle part 7a under idle conditions. The same representation also applies to the lower part of the machine. It is expedient that the side parts 7b and 7c of the lower cassette are also held pressed by (then directed downwards) tensile forces on the lower adjusting wedges 21a, 22a, so that the pairs of side parts 7b and 7c lying one above the other diverge by the same angle.

It can be seen from the introductory description of the drawing that the outer groups of support rollers 15 and 17 are arranged on the pivotable side parts 7b, 7c and thus also assume the kink position shown in FIG. 4. These idler rollers 15, 17 would not rest against the straightening rollers 3 under idling conditions and would strike them when the straightening load occurred. So that any traces of such impacts are not transferred to the straightening material, the "Double Chock Bending" system is used for the bearing housing 4 of the straightening rollers 3 in order to pre-bend the outer ends of the straightening rollers 3 in the sense that they also run at idle speed Support rollers 15, 17 abut, which are also in a kink position relative to the central support rollers 13. In order to set such a pre-bending of the straightening rollers, the bearing housings 4 are pulled at their inner ends facing the straightening rollers 3 by prestressed second tension members 26 in the direction of the side parts 7b and 7c and pressed at their outer ends by prestressed pressure members 27, the tension members 26 and the pressure members 27 are both supported on the side parts 7b and 7c of the cassette 7. To generate the prestressed tensile and compressive forces, packets of disc springs are used which act on tie rods 26a and push rods 27a. The tie rods 26a are connected to the bearing housings 4 in a tensile manner. Due to the oppositely directed pairs of forces from the tension members 26 and the pressure members 27, 4 torques act on the bearing housings, which pre-bend the straightening rollers at their ends even under no-load conditions until they rest against the outer support rollers 15, 17 fixed to the side parts.

Returning to FIG. 4, it is thus ensured that the straightening rollers defy the diverging position of the outer support rollers 15, 17 against them even under idle conditions. The advantageous function of the non-rigid cassette 7 becomes clear when the fully extended kink position shown by moving the rigid supports 20 (via the adjusting devices 6) and the adjusting position of the adjusting wedges 21a and 22a under the directional force and utilization of the intermediate joints 8 and 9 changes into the dashed lines 1 and shown in FIG. 1, the extended position of the cassette 7, in which all the groups of support rollers 15, 13, 17 are then inevitably aligned horizontally and the straightening rollers 3 are straight. The backbend of the pre-bent straightening rollers is gentle in this case, since it only takes place at the ends of the straightening rollers.

The construction of the straightening rollers 3 to the right for regrinding the straightening rollers is possible in the construction according to FIG. 1 in a conventional manner if the tensile connections between the tension rods 26a of the prestressed tension members 26 are released and the pressure rods 27a of the elastic ones Pressure members 27 are released. The manual work associated with this can, however, be avoided if the entire cassette 7, including support rollers and upper and lower rollers, is designed as an exchangeable cassette. As shown in detail for the prestressed tension member 24, the tension members 23, 24 and 25 are designed as piston-cylinder units, the pistons 30 of which are spring-loaded in the pulling direction by plate springs 31 and can be acted upon by a pressure medium in the opposite direction. The piston rods 32 (FIG. 3) pass through the outer wall of the box-shaped cassette parts in elongated holes 33 and are provided at the free ends with collars 34 which transmit the tensile force. The elongated holes 33 are expanded against the direction of removal A of the cassette to a diameter B which is larger than the diameter of the collar 34. In this extended position, the crosshead 2 is raised or lowered by the adjusting devices 6, so that the upper or lower Cassette 7 together with the parts connected to it can be removed.

Claims (4)

1. Straightening machine for metal plates and strips with upper and lower straightening rolls which are arranged one displaced relative to the other and supported over their length by backing rolls, which are borne in bearing blocks and in their turn supported at crossbeams, of which at least the upper crossbeam is adjustable for the positioning of the straightening rolls, with exchangeable cassettes between the crossbeams and the straightening rolls for the exchanging of a respective set of straightening rolls and backing rolls, wherein the backing rolls are presettable in groups, which are disposed to both sides of the central vertical transverse plane of the crossbeams and the straightening rolls, through articulated construction of the exchangeable cassettes in the manner that, subject to consideration of the bending of the crossbeams under the straightening force, the bending of the straightening rolls is compensated for, i.e. the straightening rolls are straight during the straightening, characterised thereby, that the exchangeable cassettes (7) for a one-piece construction of the crossbeam (2) consist of three parts (7a, 7b, 7c), which are connected together each time by two intermediate joints (8, 9) and carry the bearing blocks (12, 14, 16) of the groups of backing rolls (13, 15, 17), that the middle part (7a) of each cassette is supported in the region of its ends symmetrically to the central transverse plane (Q) of the crossbeams and the straightening rolls at the associated crossbeam by way of two rigid seatings (20), which are arranged at a spacing each from the other, and that each outer side part (7b, 7c), connected by way of an intermediate joint with the middle part, is associated in the region of the outermost backing rolls (15, 17) with a setting device (21, 22) limiting the pivotal position of the side part relative to the associated crossbeam.
2. Straightening machine according to claim 1, characterised thereby, that the setting devices consist of adjusting wedges (21a, 22a), which extend transversely to the straightening rolls (3) and in every adjustment position extend over the length of the cassette (7) as seen in direction of advance of the stock to be straightened, and that the cassettes are urged against the rigid seatings (20) and the adjusting wedges (21a, 22a) by biassed first tension members (23, 24, 25) fixed at the associated crossbeam.
3. Straightening machine according to claim 2, characterised thereby, that the bearing housings (4) of the straightening rolls (3) are drawn at their inner ends facing the straightening rolls in the direction of the side parts by biassed second tension members (26) fixed at the articulatedly movable side parts (7b, 7c) of the cassette (7) and stand at their outer ends under the influence of biassed compression members (27), which bear against the side parts and exert a compression force on the bearing housings so that bending moments, which bend the straightening rolls also under idling conditions at their ends until abutment at the outer backing rolls (15, 17) fixed at the side parts, engage at the bearing housings.
4. Straightening machine according to claim 3, characterised thereby, that the biassed first tension members (23, 24, 25) consist of piston-cylinder units, the pistons (30) of which are spring-loaded (31) in direction of tension and loadable by a pressure medium in the opposite direction, that the piston rods (32) engage in elongate holes (33) through the outer walls of the box-shaped cassette parts (7a, 7b, 7c) and are provided at the free ends with collars (34) transmitting the tension force and that all elongate holes are enlarged opposite to the disassembly direction (A) of the cassette (7) to a diameter (B), which is greater than the diameter of the collars of the piston rods.

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