EP4117834B1 - Roll stand for rolling a metal strip - Google Patents

Description

The present invention relates to a roll stand for rolling metal strip and a rolling train with a plurality of roll stands according to the invention arranged one behind the other in the material flow direction. A generic rolling stand is out JP S60 176801 U known.

The invention relates in particular to rolling stands with an odd number of rolls, more particularly with three, five or seven rolls. In contrast to a conventional duo, quarto or sexto stand with two, four or six rolls, in the roll stand according to the invention the upper or lower conventional work roll is replaced by a small work roll and an additional roll, either on the top or on the underside of the metal strip to be rolled. Such roll stands are basically known in the prior art.

This is what the Japanese patent application reveals JP 2010075985 a roll stand with five rolls, the upper work roll being particularly small, in particular smaller than the lower work roll. Providing the work roll with a smaller diameter offers the advantage that high-strength steels with high forming resistance can be rolled more easily because the required rolling forces can be reduced due to the smaller work roll diameter.

Also the Japanese patent application JP 61245904 A discloses a roll stand with five rolls arranged one above the other, the upper work roll having a smaller diameter than the lower work roll. The Japanese patent application recommends this stand structure specifically for asymmetrical rolling of clad steel plates. The clad steel plates have a different forming resistance on their top and bottom sides and it is therefore recommended to roll such steel plates with different circumferential speeds of the work rolls, as shown by the Work rolls with different diameters are realized at the same drive speed. A second upper work roll has the same diameter as a conventional work roll, that is, the first and second work rolls taken together, when stacked one above the other, have a greater height than a single conventional work roll. The work roll with the smaller diameter is used on the side of the clad material to be rolled which has a larger forming resistance; Conversely, the work roll with the larger diameter attaches to the side of the clad material, which has a lower forming resistance. The smaller diameter work roll is pivotally mounted relative to the conventional larger diameter work roll; In particular, the smaller work roll can be pivoted away from the vertical line of force. This means that, depending on requirements, it can either be provided in the vertical power transmission direction or can be pivoted away; In the latter case, the roll stand can be operated as a normal four-high stand, in which the two opposite work rolls each have the same diameter. In this respect, this is what the Japanese patent application offers JP 61245904 A revealed rolling stand expanded rolling possibilities. However, a change between the two roll constellations described not only requires the work roll with the smaller diameter to be swiveled in or away, but also a vertical movement of the two rolls arranged above the small work roll within the roll stand.

Furthermore, please refer to the European patent application EP 0 114 795 A referred. This application discloses a traditional four-roll stand with a total of four rolls arranged one above the other, ie two internal work rolls, which span a roll gap and with an upper support roll arranged above the upper work roll and with a lower support roll arranged under the lower work roll. For the two work rolls, which appear to have the same diameter here, a horizontal hydraulic support device is provided on both sides, each with a support shell is pressed against the surface of one of the work rolls and a lubricant is pumped into a space between the support shell and the respective work roll using a pump device. The disclosed horizontal support device serves in particular to increase the horizontal rigidity or stability of the stand as a whole, which is particularly advantageous when cold rolling thin strips with high forming resistance.

The invention is based on the object of developing a known roll stand with an odd number of rolls arranged one above the other in such a way that lateral bending of the small work roll is effectively prevented.

This task is solved by the subject matter of patent claim 1.

The roll stand according to the invention has a support device for the small work roll that acts at least on one side in the horizontal direction and an adjusting device for horizontally adjusting the support device against the small work roll.

The support device preferably supports the small work roll not only on one side, but on both sides.

By providing the support device, lateral bending of the small work roll is effectively prevented and thus the overall rigidity of the roll stand with the odd number of rolls is increased. Due to the stability of the additional roll, which is arranged between the small work roll and the second support roll or the second intermediate roll, the required performance of the support device for stabilizing the entire roll stand is lower compared to the work roll stabilization in a conventional roll stand with four or six one above the other arranged rollers, in which the two work rollers each have the same diameter.

For the purposes of the present invention, the term “work roll” means a roll that is in direct contact with the rolling stock and carries out the forming work.

Work rolls of different sizes are provided. The work roll referred to in the present application as a large work roll corresponds to a regular work roll typically used in practical use.

When using a small work roll, it always replaces a large work roll in conjunction with an additional roll, resulting in a roll set with an odd number of rolls.

In the context of the present description, the term “adjusting device” means not only a preferably hydraulically operating device for variably adjusting the support device, in particular its support shells, against the small work roll, but also expressly a static, i.e. H. non-variable holding device for stationary positioning of the support device on the small work roll.

According to the invention, the size ratios mean that the small work roll has a smaller diameter than the additional roll and the additional roll has a smaller diameter than the large work roll.

The roll stand according to the invention can alternatively be designed with or without backup rolls and/or intermediate rolls.

In a first preferred embodiment variant, a first support roll is provided for supporting the large work roll and a second support roll for supporting the additional roll, both support rolls having a larger diameter than the large work roll. Particularly preferred is in In this context, it is provided that the two support rollers have an identical diameter.

In a further embodiment variant, a first intermediate roll arranged between the large work roll and the first support roll and a second intermediate roll arranged between the additional roll and the second support roll are provided, the first intermediate roll having a larger diameter than the large work roll and a smaller diameter than the first support roll and the second intermediate roller has a larger diameter than the additional roller and a smaller diameter than the second backup roller. In this context, it is particularly preferred that the two intermediate rollers have an identical diameter.

For driving the rolls of the roll stand, various drive concepts are possible with the present invention.

In one embodiment variant, the roll stand has only one drive device for rotating the large work roll. Optionally, the drive device can also drive the additional roller. If the large work roll and the additional roll are driven simultaneously, it must be ensured that the drive device drives the two rolls with the same directions of rotation and, if necessary, with an adjusted speed.

In a further embodiment variant, the roll stand has a drive device for rotationally driving the first support roll and/or the second support roll. If the first and second support rollers are driven simultaneously, it must be ensured that the drive device drives the two rollers with the same directions of rotation.

In a further embodiment variant, the roll stand has a drive device for rotationally driving the first intermediate roller and/or the second intermediate roller. If the first and second intermediate rollers are driven simultaneously, it must be ensured that the drive device drives the two rollers with the same directions of rotation.

In general, this has the advantage that with the odd number of rolls in the roll stand according to the invention, it is ensured that the two work rolls, which together span the roll gap, work together and not against each other.

Advantageously, the small work roll and the additional roll are arranged together and rotatably mounted in an exchange insert.

According to a further exemplary embodiment, the support device has at least one support shell for pressing against the small work roll at least on one side, preferably on both sides. A pump device is provided for pumping a fluid into an intermediate space between the at least one support shell and the small work roll. The support device is advantageously located within the said replacement insert. This saves space and, in particular, makes sense because, according to the invention, the support device is only intended for the small work roll.

The fluid pumped into the gap, which is preferably in the form of a cooling lubricant, serves as a hydrostatic cushion and also for effective cooling of the small work roll. The size of the gap, but also the stability of the horizontal support, can be changed by adjusting the pressure value of the fluid and/or its volume flow. The setting and regulation of pressure and/or volume flow is intended to set optimal horizontal support.

Since the claimed replacement insert only concerns the small work roll and the additional roll, flatness actuators of all other rolls, i.e. the support rolls and/or the intermediate rolls, can remain in operation unchanged outside of the replacement insert; this concerns e.g. B. Bending cylinders for bending rolls, Continuously Variable Crown CVC adjustment devices for axial displacement, adjustment devices for horizontal displacement or zone cooling devices.

Advantageously, it is provided that the external geometric dimensions, in particular the total height of the replacement insert with the small work roll and the additional roll, at least partially correspond to the external geometric dimensions, in particular the diameter of the opposite large work roll, or the diameter of a traditional duo, quarto, or sexto framework largely corresponds. This means that the invention can be implemented particularly easily in the context of modernizations. For new systems, deviations of up to 30%, preferably up to 20%, are permitted compared to the large work roll. The conversion of a traditional duo stand with two rolls arranged one above the other, a quarto stand with four rolls arranged one above the other or a sexto stand with six rolls arranged one above the other to the roll stand according to the invention with an odd number of rolls and the small work roll and the additional roll is then possible very easily and quickly with the help of the exchange insert used, because its dimensions fit well into the existing receptacles for the conventional work roll chocks. In this respect, the rolling stand can be expanded very flexibly in terms of its rolling options thanks to the claimed replacement insert. The same applies to the conversion into a conventional duo, quarto or sexto configuration.

The present invention can also be used to expand the rolling options in single stands or tandem lines, in one-way or Reversing operation. When using the roll stand according to the invention in conjunction with only one driven roll, effects on the structure due to the asymmetrical roll gap conditions (small and large work rolls with different diameters) must be taken into account. The effective effects on the structure of the metal strip to be rolled in the so-called drag drive result from the displacement of the flow blade position between the driven and non-driven work roll. By actively adjusting the speeds or torques of the individual drives, the roll gap can be further actively influenced. The adjustment of the horizontal offset of the small work roll via a displacement/movement of the support shells as well as the offset of the entire insert or other rolls is set or regulated using a process model and/or taking into account necessary parameters, in particular measured strip tensions, rolling forces and/or moments.

In addition, the rolling stands according to the invention enable a higher rolling speed than the conventional rolling stands, in particular also known multi-roll stands; For example, rolling speeds of more than 800 m/min are possible. Of course, a normal procedure for products other than thin strips made of high-strength steel is still possible to a limited extent. The rolling stands according to the invention are used in particular for cold rolling high-strength thin metal strips.

The horizontal offsets of the small work roll and the additional roll of the replacement insert are adjusted with the help of the pressing device so that the lateral forces on the support shells are set to a minimum or in a range that makes sense for the load. With single or twin drives, the measured motor currents can be used to calculate the horizontal forces. This is not completely possible with comb roller drives due to unknown torque distortions.

When arranging the replacement insert above the metal strip: Since the rolling friction is usually lower due to the lake of cooling lubricant on the top, the drive power is transmitted via the bottom with a reduced risk of slipping.

If the insert is positioned below the metal belt: The cooling lubricant emerging from the support shell only reaches the belt to a small extent. On the top side, conventional cooling lubricant systems or belt blow-off systems can still be used as is known.

A reduction in roll gap friction can be achieved for the small, non-driven work roll by additional application of cooling lubricant, application of concentrate/additive or cooling lubricant with enriched concentrate/additive content.

The replacement insert can be integrated as a whole into a bending or axial/horizontal displacement system.

Figur 1

eine Ausführungsvariante des erfindungsgemäßen Walzgerüstes;

Figur 2

verschiedene Konstellationen des erfindungsgemäßen Walzgerüstes mit einer Anordnung der kleinen Arbeitswalze und der Zusatzwalze oberhalb des Metallbands; und

Figur 3

verschiedene Konstellationen des erfindungsgemäßen Walzgerüstes mit einer Anordnung der kleinen Arbeitswalze und der Zusatzwalze unterhalb des Metallbands.

The invention and the technical environment are explained in more detail below using the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and/or figures. In particular, it should be noted that the figures and in particular the proportions shown are only schematic. The same reference numbers designate the same objects, so that explanations from other figures can be used in addition if necessary. Show it:

Figure 1

an embodiment variant of the roll stand according to the invention;

Figure 2

different configurations of the rolling stand according to the invention with an arrangement of the small work roll and the additional roll above the metal strip; and

Figure 3

different configurations of the rolling stand according to the invention with an arrangement of the small work roll and the additional roll below the metal strip.

Figure 1 shows in its right half an embodiment variant for the roll stand 100 according to the invention for rolling metal strip 200. The roll stand has a small work roll 110 and an additional roll 111 which is operatively connected to it, as well as a large work roll 120. As per the Figure 1 As can be seen, the small work roll 110 and the large work roll 120 create a rolling gap for rolling the metal strip 200. The additional roll 111 has a larger diameter than the small work roll 110, but a smaller diameter than the large work roll 120 arranged opposite the small roll 110.

Advantageously, the sum of the diameters of the small work roll 110 and the additional roll 111 - when arranged vertically one above the other - largely corresponds to the diameter of the large work roll 120. This makes it easier to replace the small work rolls 110 and the additional roll 111 with a conventional work roll, the diameter of which is the sum of the corresponds to both rollers 110, 111, especially if these two are rotatably arranged in an exchange insert 130. In comparison, in the left half, a conventional work roll 140 is shown with its chock or bearing housing 141. According to the invention, the external geometric dimensions, in particular the overall height of the replacement insert 130 with the two rollers 110, 111, correspond to the external geometric dimensions, in particular the diameter of the opposite one Work roll 120 and the conventional work roll 140 match. This makes a simple replacement very quick and easy.

Ideally, equality is the aim, but deviations can arise due to the grinding area of the rollers used. There may also be deviations from the design. Overall, an upward or downward deviation of up to 20% is tolerable.

In Figure 1 It can also be seen that the small work roll 110 is supported against horizontal or lateral bending, preferably on both sides in the horizontal direction, with the aid of a horizontal support device 150. For this purpose, the support device 150 is positioned against the small work roll 110 with the aid of, for example, a hydraulically operating adjusting device 160. To be more precise, not the entire support device 150, but only its support shell 155 is placed against the small work roll 110. Furthermore, a pump device 170 is provided for pumping fluid or cooling lubricant into the gap 175 between the support shell 155 and the small work roll 110. This is preferably done as in Figure 1 is shown, on both sides of the small work roll 110.

Figure 2 shows in partial images a) to i) various exemplary embodiments of the rolling stand 100 according to the invention, in which the small work roll 110 supported by the additional roll 111 is arranged above the metal strip 200 to be rolled. The exemplary embodiment a) corresponds to that previously referred to Figure 1 described first embodiment. What is characteristic of this exemplary embodiment is that only the large work roll 120 arranged below the metal strip 200 is driven in rotation in accordance with the direction of rotation of the arrow. All other rolls of the roll stand 100 and in particular the small work roll 110 are not rotationally driven. In contrast to exemplary embodiment a), in exemplary embodiment b) both those below the metal strip 200 arranged large work roll 120 as well as the additional roll 111 are rotationally driven in accordance with the direction of rotation of the arrow.

The exemplary embodiments according to Figure 2c) to 2e ) each relate to a roll stand with 5 rolls. In comparison to the previous exemplary embodiments, these additionally include a first support roll 180 and a second support roll 185. The first support roll 180 is in operative connection with the large work roll 120 and has a larger diameter than it. The second support roller 185, on the other hand, is in operative connection with the additional roller 111 and has a larger diameter than it. The drive concept of exemplary embodiments 2c) and 2d) corresponds to that of exemplary embodiments 2a) and 2b). For exemplary embodiment 2e), only the first support roller 180, or only the second support roller 185, or both the first and second support rollers 180, 185 can be rotationally driven simultaneously, according to the direction of rotation of the arrow.

The exemplary embodiments according to Figure 2f) to 2i ) each relate to a roll stand with 7 rolls. In comparison to the previous exemplary embodiments according to 2c) to 2e), these additionally include a first intermediate roll 190 and a second intermediate roll 195. The first intermediate roll 190 is arranged between the first support roll 180 and the large work roll 120 and points one towards the large work roll 120 larger diameter and one smaller than the first support roller 180 diameter. The second intermediate roller 195 is arranged between the second support roller 185 and the additional roller 111 and has a larger diameter than the additional roller 111 and a smaller diameter than the second support roller 185. The drive concept of exemplary embodiments 2f) and 2g) corresponds to that of exemplary embodiments 2a) to 2d). For exemplary embodiments 2h) and 2i), only the first support roller 180 or alternatively only the first intermediate roller 190, or only the second support roller 185 or alternatively only the second intermediate roller 195, or both the first and the second support rollers 180, 185 or alternatively the first and second intermediate rollers 190, 195 are rotationally driven simultaneously, according to the direction of rotation of the arrow.

Figure 3 shows in the partial images a) to i) various exemplary embodiments of the rolling stand 100 according to the invention, in which the small work roll 110 supported by the additional roll 111 is arranged below the metal strip 200 to be rolled. In this respect, those previously referred to apply Figure 2 Statements made about the exemplary embodiments shown there for the exemplary embodiments according to Figure 3 equally or analogously.

Reference symbol list

100

Roll stand

110

small work roll

111

additional roller

120

large work roll

130

Exchange use

140

conventional work roll

141

Chock/bearing housing

150

hydraulic support device

155

Support shell

160

Hiring device

170

Pump device for cooling lubricants

175

space

180

first support rollers

185

second support roller

190

first intermediate roller

195

second intermediate roller

200

metal band

Claims (16)

1. Roll stand (100) for rolling metal strip (200), comprising:

   a small work roll (110) and an oppositely arranged large work roll (120), which together bound a rolling gap for rolling the metal strip (200);

   an additional roll (111) by way of which the small work roll (110) is supported, wherein the small work roll (110) has a diameter which is smaller with respect to the additional roll (111);

   a support device (150), which acts on at least one side in horizontal direction, for the small work roll (110); and

   an adjusting device (160) for horizontal adjustment of the support device (150) relative to the small work roll (110);

   characterised in that

   the additional roll (111) has a diameter which is smaller with respect to the large work roll (120).
2. Roll stand (100) according to claim 1,
   characterised by
   a first backing roll (180) for supporting the large work roll (120) and a second backing roll (185) for supporting the additional roll (111), wherein the two backing rolls (180, 185) have a diameter which is larger with respect to the large work roll (120).
3. Roll stand (100) according to claim 2,
   characterised in that
   the two backing rolls (180, 185) have an identical diameter.
4. Roll stand (100) according to claim 2 or 3,
   characterised by

   a first intermediate roll (190) arranged between the large work roll (120) and the first backing roll (180), wherein the first intermediate roll (190) has a diameter which is larger with respect to the large work roll (120) and a diameter which is smaller with respect to the first backing roll (180); and

   a second intermediate roll (195) arranged between the additional roll (111) and the second backing roll (185), wherein the second intermediate roll (195) has a diameter which is larger with respect to the additional roll (111) and a diameter which is smaller with respect to the second backing roll (185).
5. Roll stand (100) according to claim 4,
   characterised in that
   the two intermediate rolls (190, 195) have an identical diameter.
6. Roll stand (100) according to any one of the preceding claims,
   characterised by

   a drive device for rotational drive of the large work roll (120) and - optionally - additionally the additional roll (111); or

   a drive device for rotational drive of the first backing roll (180) and/or the second backing roll (185); or

   a drive device for rotational drive of the first intermediate roll (190) and/or the second intermediate roll (195).
7. Roll stand (100) according to claim 6,
   characterised in that
   in the case of drive of the large work roll (120) and additionally the additional roll (111) the drive device is constructed to rotationally drive the two rolls (111, 120) respectively in the same rotational directions and optionally with matched rotational speed.
8. Roll stand (100) according to claim 6,
   characterised in that
   in the case of drive of the first backing roll (180) and the second backing roll (185) the drive device is constructed to rotationally drive the two backing rolls (180, 185) respectively in the same rotational directions.
9. Roll stand (100) according to claim 6,
   characterised in that
   in the case of drive of the first intermediate roll (190) and the second intermediate roll (195) the drive device is constructed to rotationally drive the two intermediate rolls (190, 195) respectively in the same rotational directions.
10. Roll stand (100) according to any one of the preceding claims,
    characterised in that

    the support device (150) comprises at least one support shell (155) for pressing on at least one side against the small work roll (110); and

    a pumping device (170) is provided for pumping a fluid into an intermediate space (175) between the at least one support shell (155) and the small work roll (110).
11. Roll stand (100) according to any one of the preceding claims,
    characterised in that
    the small work roll (110) and the additional roll (111) are arranged coherently and to be rotatable relative to one another in an exchange insert (130).
12. Roll stand (100) according to claim 11,
    characterised in that
    the external geometric dimensions, particularly the overall height of the exchange insert (130) with the small work roll (110) and the additional roll (111), correspond at least partly to the external geometric dimensions, particularly the diameter, of the large work roll (120).
13. Roll stand (100) according to claim 11 or 12,
    characterised by
    at least one planarity setting element associated with the exchange insert (130) with the small work roll (110) and the additional roll (111), the backing rolls (180, 185) and/or the intermediate rolls (190, 195).
14. Roll stand (100) according to any one of the preceding claims,
    characterised in that
    the roll stand (100) is an individual stand or a tandem rolling train in single-pass or reversing operation.
15. Roll stand (100) according to any one of the preceding claims,
    characterised in that
    the roll stand (100) is constructed as a cold-rolling stand for cold-rolling of the metal strip (200).
16. Tandem rolling train with a plurality of roll stands (100) arranged in succession in material flow direction,
    characterised in that
    the roll stands (100) are constructed according to any one of the preceding claims.

Images