JP2002066608A - Cold rolling mill and rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of scratches on the surface of a rolling material and a trouble of responsivity in cold rolling, to properly respond to a variation of a thermal crown that momentarily varies while rolling, and to prevent the deterioration of the whole shape of a plate. SOLUTION: In a six-stage rolling mill, a local pit-shaped crown 2a having a club shape towards its tip is formed at one end of each working roll 2 that comprises a shifting unit, the working rolls 2 are so disposed as to be symmetric with respect to a top-and-bottom point. A decrease bender 10b that acts to narrow a gap between the working rolls is mounted as a first shape-controlling means, and the local pit-shaped crown 2a is used together with the roll bender 10b for controlling the thermal crown. In order to compensate a variation of a body crown caused by use of the roll bender, an increase bending unit 11a that controls a deflection of an intermediate roll 3 is mounted as a second shape-controlling means capable of controlling a shape of the center part of the rolling material at least to the pit-shaped crown side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling mill and a rolling method, and more particularly to a four or more-stage cold rolling mill applied to a reversible cold rolling facility, an aluminum and copper rolling facility, and the cold rolling mill. The present invention relates to a rolling method using a mill.

[0002]

2. Description of the Related Art In the rolling of a cold metallic steel strip, a change in the roll diameter in the width direction caused by a difference in the thermal expansion of the roll, that is, a so-called thermal crown, is generated based on a change in the temperature of the roll in the axial direction near the end of the plate. This is because the roll is heated more strongly in the sheet path than other portions due to the heat generated during processing of the rolled material during rolling and the frictional heat generated between the roll and the rolled material. When this thermal crown is large, the so-called edge-up shape in which the plate thickness near the plate edge is increased,
This does not result in a uniform plate thickness, resulting in a decrease in product yield. Further, when the thermal crown is large, the tension applied at the time of rolling strongly acts on the vicinity of the plate edge or the edge portion is strongly pulled by the internal tension distribution, so that the risk of plate breakage sharply increases. In particular, in the case of soft materials such as aluminum and copper, the rolling load is generally small, so the plate thickness sharply decreases due to the Hertz flattening of the roll near the plate edge, the so-called edge drop amount is smaller than that of general steel plate rolling. This effect is very strong, and this danger is extremely large. Further, in the case of aluminum rolling, since flammable rolling oil having a low flash point is usually used, sparks generated at the time of sheet breaking may ignite the rolling oil and cause a fire. Therefore, in such a state, a careful operation such as lowering the rolling speed is usually performed. This not only impairs operability, but also causes a decrease in productivity.

[0003] Further, in a reversible cold rolling equipment that performs rolling while repeating winding and unwinding with a winding machine,
The edge-up shape generated by the thermal crown is harmful. This is because when winding a rolled material having an edge-up shape, the winding machine becomes a so-called drum-shaped build-up shape in which both ends of the plate are swelled. This is because the sex is increased. In particular, it is very difficult to completely remove the rolling oil on the surface of the rolled material with the cold reversible rolling equipment. The danger is increasing. This not only impairs the operability of the cold rolling equipment, but also leaves a serious problem in product quality.

Conventionally, the following coolant control has been generally performed to solve the problems caused by the thermal crown in the cold rolling.
Hereinafter, a technique related to the conventional thermal crown control including hot rolling will be described, and a related technique related to a local roll diameter gradually increasing portion provided to a roll end of a work roll employed in the present invention will be described.

<Coolant control> For example, plasticity and processing,
vol. 23 no. 263 (1982-12) "Effect of Coolant Zone Control on Shape Control of Aluminum Cold Rolling", etc. Is generally performed well.
In addition, as the coolant control, it is conceivable that the temperature of the roll cooling liquid added near the plate edge is made higher than others. In any case, the current situation is that coolant control alone has not achieved sufficient results for thermal crowns. In particular, in aluminum and copper rolling, mineral oil-based coolant oil is generally used, and its viscosity is higher than that of steel plate rolling equipment using water-soluble coolant oil. It can be said that there is.

<Hot Rolling-Work Roll Full Length Initial Concave Crown> Even with hot rolling, there is a problem of a thermal crown. However, in a normal hot rolling facility, the final sheet thickness is about 1.6 mm even if it is thin, and the sheet thickness is thicker than that of cold rolling, which is about 0.2 mm, and the influence of the thermal crown is relatively small. . Further, hot rolling oil or cooling water applied to the strip surface during rolling or the like is burned off before winding, and therefore hardly remains on the strip surface during winding. Even if a small amount remains, the friction between the cold-rolled material and the cold-rolled material is much greater from the surface scale on the take-up strip and the like, and it is unlikely to cause winding deviation. Furthermore, when a hot-rolled material is directly used, it is often used for building materials and the like, and the surface quality such as damage is not as severe as that of a cold-rolled material.
For these reasons, control of the thermal crown is not strictly required in hot rolling as in cold rolling. Therefore, in hot rolling, in order to reduce the thermal crown, including the role of roll wear measures, use a work roll with a concave crown that is tapered from the roll center toward the roll end over the entire length of the roll, It is usually dealt with. Conversely, in cold rolling, the surface quality and the like are directly linked to the quality of the final product, and it is understood that strict control of this is particularly important.

<Japanese Patent Application Laid-Open No. 9-239411> When a high-speed steel roll having excellent wear resistance is used as a work roll even in a hot rolling facility, the thermal crown is controlled because the high-speed steel roll has a large linear expansion coefficient. Is important. Japanese Patent Application Laid-Open No. 9-239411 discloses, as a solution, a four-high rolling mill in which a concave crown (single crown) that gradually becomes thicker is provided from a middle part of a movable work roll to a roll end. . This can be said to be very effective for controlling the thermal crown. However, if this technique is applied to cold rolling as it is, there is a problem that the plate shape of the whole rolled material is deteriorated, and there is a risk that the surface of the rolled material is damaged (described later).

Japanese Patent Application Laid-Open No. 5-76905 discloses that a roll end on one side of a work roll is tapered (local concave crown is provided) for purposes other than thermal crown control. There is the cold tandem rolling technology described. In order to prevent cracking (edge cracking) of the plate edge, which is a problem when rolling a brittle silicon steel plate using a cold tandem rolling mill, a local concave crown is applied to one roll end. The applied work roll is applied to the first stand, and the second and subsequent stands are rolled using a work roll provided with a locally convex crown on one end of the roll. That is, a compressive residual stress is generated by forcibly reducing the edge of the plate with the locally concave crown of the work roll at the first stand, and cracking (edge cracking) of the plate edge which becomes a problem in rolling of a silicon steel plate as a brittle material. ) To prevent. However, if the first stand is strongly pressed down near the plate edge in this way, the edge drop becomes large,
To compensate for this, the second and subsequent stands are rolled by a rolling mill having locally convex crown rolls.

Japanese Patent Application Laid-Open No. 11-123431 discloses another conventional technique in which the end of a work roll is tapered (local concave crown is provided) for purposes other than thermal crown control. Tandem rolling technology described in This is a pair of upper and lower work rolls in which the roll diameter on one side is gradually increased toward the end in order to prevent the occurrence of heat scratches and prevent the occurrence of plate breakage in cold tandem rolling. Are arranged symmetrically with respect to a point so that the work roll can be shifted in the axial direction and a bender force is applied, and cold rolling is performed by applying a tension of 0.3 or more at a tension load ratio. By adjusting the moving amount of the work roll so that the target end elongation is obtained at the end of the plate, and adjusting the work roll bender force so that the center of the plate becomes flat, the plate breaks even when the rolling speed is increased It is said that stable operation can be performed without generating heat scratch.

[0010]

As described above, the thermal crown causes various problems in cold rolling. In order to deal with such a problem, coolant control for controlling the roll cooling amount in the sheet width direction is generally performed, but this alone has not produced sufficient results. In addition, even if the thermal crown is rolling the same rolled material,
It changes from moment to moment. Responsiveness of the coolant control to such a change in the thermal crown during rolling is slow, and it cannot be said that this point is sufficient.

In order to control the thermal crown which changes every moment during rolling, a technique of giving an initial concave crown to the entire length of a work roll by hot rolling is disclosed in JP-A-9-239.
No. 411 describes a concave crown (single crown) that gradually becomes thicker from the middle of the roll to the end of the roll.
It is conceivable to apply a technique using a movable work roll marked with, to a cold rolling mill, and change and control the position of the work roll according to the amount of change in the thermal crown. However, moving the work roll during rolling has a risk of causing scratches on the surface of the rolled material, and is not preferable in cold rolling equipment, particularly in rolling of a soft material such as aluminum. In addition, the response is slow and not sufficient.

JP-A-5-76905 and JP-A-11-76905
In the technique described in JP-A-123431, the roll end on one side of the work roll is tapered (local concave crown is provided) for purposes other than thermal crown control. Further, even if a mobile work roll provided with a local concave crown is used to solve the problem related to the thermal crown, as in the case described above, there is a problem of scratches on the rolled material surface and responsiveness.

The shape is controlled by applying the above-mentioned work roll piece crown or locally concave crown to the thermal crown which changes every moment during rolling, and bending the work roll by applying an external force to the end of the work roll. It is also conceivable to use a so-called roll bending technique together. In this case, if the work roll vendor is controlled instead of the work roll movement in response to the change in the thermal crown during rolling,
The problem of scratches and responsiveness on the rolled material surface can be solved.

However, the difficulty in controlling the thermal crown is that it is caused by local thermal expansion deformation of the roll near the plate edge. Control of the generated thermal crown is generally very difficult with the roll bending technique. This is because the bending of the roll due to roll bending acts over the entire length in the roll axis direction, so that local roll deformation near the plate edge cannot be appropriately controlled.

That is, if the thermal crown, which changes every moment, is controlled only by the work roll bender during rolling, the sheet crown near the center of the rolled material (hereinafter, appropriately referred to as the body crown) also changes greatly. Therefore, initially,
Even if the work roll is set at an appropriate movement position, if the thermal crown, which changes largely at the plate edge mainly with the progress of rolling thereafter, is controlled only by the work roll bender, the body crown also changes because the thermal crown also changes. Of the plate is deteriorated. This is due to poor compatibility between the thermal crown shape generated around the plate edge and the effect of the work roll bender on the plate crown shape (hereinafter, edge crown) mainly near the plate edge.

An object of the present invention is to provide a cold rolling method that does not cause scratches on the surface of a rolled material or a problem of responsiveness, can appropriately cope with a change in the thermal crown that changes from time to time during rolling, and furthermore, can reduce the entire plate. An object of the present invention is to provide a cold rolling mill and a rolling method that do not deteriorate the shape.

[0017]

(1) In order to achieve the above object, a cold rolling mill according to the present invention comprises: a first shift device capable of moving a pair of upper and lower work rolls in directions opposite to each other;
In a cold rolling mill having at least four or more stages provided with a roll bending device for controlling the bending of the pair of upper and lower work rolls, provided at one of the roll ends of the pair of upper and lower work rolls, and symmetrical with respect to the upper and lower points. A local roll diameter gradually increasing portion that gradually becomes thicker and arranged so as to be
First shape control means for controlling a thermal crown formed on each of the pair of upper and lower work rolls in combination with the local roll diameter gradually increasing portion; and controlling a shape of a central portion of the rolled material to at least a concave crown side. It is provided with a second shape control means that can be used.

By providing the local roll diameter gradually increasing portion and the first and second shape control means as described above, the change of the thermal crown during rolling is controlled by the first shape control means,
The change in the overall shape of the rolled material, that is, the change in the body crown, caused by the operation of the first shape control means can be controlled by the second shape control means. Instead, it is possible to appropriately cope with a change in the thermal crown that changes every moment during rolling, and it is possible to perform rolling without deteriorating the overall plate shape.

(2) In the above (1), preferably,
The roll bending device includes a Decrease bending device that acts in a direction to reduce a gap between the pair of upper and lower work rolls, and the first shape control unit is the Decrease bending device.

Thus, the first shape control means can control the
The thermal crown can be controlled without causing any damage on the rolled material surface or the problem of responsiveness.

(3) In the above (1), the rolling mill is a six-high rolling mill having a pair of upper and lower intermediate rolls and a second shift device capable of moving the intermediate rolls in opposite directions. The shape control means may be the second shift device.

With this, the first shape control means can control the thermal crown without causing scratches on the surface of the rolled material or problems of responsiveness during rolling.

(4) To achieve the above object,
The cold rolling mill of the present invention has at least four or more stages including a shift device that enables a pair of upper and lower work rolls to move in opposite directions, and a roll bending device that controls deflection of the pair of upper and lower work rolls. In the cold rolling mill, the pair of upper and lower work rolls has a local roll diameter gradually increasing portion that is tapered at one of the roll ends, and the local roll diameter gradually increasing portion is vertically symmetrical. And the roll bending device has a decrease bending device that acts as a first shape control means in a direction to reduce a gap between the pair of upper and lower work rolls, and further includes a central portion of the rolled material. It is provided with second shape control means for controlling the shape at least to the concave crown side.

By providing the local roll diameter gradually increasing portion and the first and second shape control means as described above, the change of the thermal crown during rolling is controlled by the first shape control means,
The change in the overall shape of the rolled material, that is, the change in the body crown, caused by the operation of the first shape control means can be controlled by the second shape control means. Instead, it is possible to appropriately cope with a change in the thermal crown that changes every moment during rolling, and it is possible to perform rolling without deteriorating the overall plate shape.

(5) In order to achieve the above object,
The cold rolling mill of the present invention includes a shift device that enables the pair of upper and lower work rolls to move in opposite directions, and a roll bending device that controls deflection of the pair of upper and lower work rolls. In the cold rolling mill of at least four stages applied to the above, the pair of upper and lower work rolls has a local roll diameter gradually increasing portion that becomes thicker at one of the roll ends, and the local roll diameter The gradually increasing portion is arranged so as to be vertically symmetrical, and the roll bending device has a decrease bending device that acts as a first shape control unit in a direction to reduce a gap between the pair of upper and lower work rolls, Further, a second shape control means for controlling the shape of the central portion of the rolled material to at least the concave crown side is provided.

By providing the local roll diameter gradually increasing portion and the first and second shape control means as described above, even when applied to a cold reversible rolling facility, the change of the thermal crown during rolling can be controlled by the first shape control means. And the change of the overall shape of the rolled material, that is, the change of the body crown by the operation of the first shape control means can be controlled by the second shape control means.
In cold reversible rolling, it does not cause scratches or responsiveness problems on the rolled material surface, can appropriately respond to the change in thermal crown that changes every moment during rolling, and enables rolling that does not deteriorate the overall plate shape Become.

(6) In order to achieve the above object,
The cold rolling mill according to the present invention includes a shift device that enables a pair of upper and lower work rolls to move in opposite directions, and a roll bending device that controls deflection of the pair of upper and lower work rolls. At least 4 applied to
In a cold rolling mill having more than one step, the pair of upper and lower work rolls has a local roll diameter gradually increasing portion that becomes thicker at one of the roll ends, and the local roll diameter gradually increasing portion is vertically symmetrical. And the roll bending device has, as first shape control means, a decrease bending device that acts in a direction to reduce the gap between the pair of upper and lower work rolls, and furthermore, the roll bending device further includes: It is provided with second shape control means for controlling the shape of the central portion to at least the concave crown side.

By providing the local roll diameter gradually increasing portion and the first and second shape control means as described above, even when applied to a cold aluminum rolling facility, the change in thermal crown during rolling can be controlled by the first shape control means. And the change in the overall shape of the rolled material, that is, the change in the body crown, caused by the operation of the first shape control means can be controlled by the second shape control means. Therefore, it is possible to appropriately cope with a change in the thermal crown that changes every moment during rolling without causing any problem in the rolling, and to perform rolling without deteriorating the overall plate shape.

(7) In the above (1), (4) to (6), preferably, the rolling mill is a six-high rolling mill having a pair of upper and lower intermediate rolls movable in the axial direction, and The control means has an increase bending device for controlling the bending of the pair of upper and lower intermediate rolls.

Thus, the second shape control means can control the shape of the central portion of the rolled material to at least the concave crown side.

(8) In the above (7), preferably,
The pair of upper and lower intermediate rolls is a local roll diameter gradually decreasing portion that gradually tapers on the same side as the local roll diameter gradually increasing portion provided at the roll end of the work roll, which is one of the respective roll ends. The roll diameter change amount of the local roll diameter gradually decreasing portion is substantially equal to or larger than the roll diameter change amount of the local roll diameter gradually increasing portion.

Thus, the increase in the contact surface pressure between the rolls due to the provision of the local roll diameter gradually increasing portion can be suppressed, and the life of the rolls can be extended.

(9) The above (1), (4) to (6)
, Wherein the rolling mill is a six-high rolling mill having a pair of upper and lower intermediate rolls, wherein the pair of upper and lower intermediate rolls has a curved roll crown provided on the entire roll and having both a maximum and a minimum, and the second shape. The control means may include a shift device that enables the pair of upper and lower intermediate rolls to move in opposite directions.

[0034] This also allows the second shape control means to control the shape of the central portion of the rolled material at least to the concave crown side.

(10) Further, the above (1), (4) to
In (6), the rolling mill is a six-high rolling mill provided with a pair of upper and lower intermediate rolls movable in the axial direction, and the second shape control means rotates at least the pair of upper and lower intermediate rolls about a center of the rolling mill. A roll cross device that inclines horizontally as a central axis may be used.

This also allows the second shape control means to control the shape of the central portion of the rolled material to at least the concave crown side.

(11) The above (1), (4)-
In (6), the rolling mill is a four-high rolling mill, and the second shape control means uses one of the pair of work rolls or a pair of upper and lower reinforcing rolls for supporting the pair of work rolls in a horizontal direction with the center of the mill substantially as a rotation center axis. It may have a roll cloth device that tilts to

This also allows the second shape control means to control the shape of the central portion of the rolled material at least to the concave crown side.

(12) Further, (1), (4) to
In (6), the rolling mill is a four-high rolling mill, and the pair of reinforcing rolls that support the work roll have a roll crown that tapers from substantially the center of the roll toward one of the roll ends. The second shape control means may be arranged so as to be vertically symmetrical, and the second shape control means may include a shift device that enables the pair of upper and lower reinforcing rolls to move in opposite directions.

This also allows the second shape control means to control the shape of the central portion of the rolled material at least to the concave crown side.

(13) In the above (1) to (12),
Preferably, the use range of the roll diameter of the pair of upper and lower work rolls is set so as to be 1 / 6Wm + 50 ≦ Dw ≦ 1 / 6Wm + 250 Dw: work roll diameter Wm: maximum usable plate width.

Thus, when the decrease bending device which acts in the direction of decreasing the gap between the pair of upper and lower work rolls is used as the first shape control means, the effect of controlling the thermal crown is ensured.

(14) Further, in order to achieve the above object, the rolling method of the present invention comprises a shift device which enables a pair of upper and lower work rolls to move in opposite directions to each other, and a deflection of the pair of upper and lower work rolls. And a pair of upper and lower work rolls having a local roll diameter gradually increasing portion that becomes thicker at one of the roll ends, and the local roll diameter gradually increasing portion is vertically symmetrical. And the roll bending device is provided with a first
As a shape control means, a decreise bending device acting in a direction to reduce a gap between the pair of upper and lower work rolls, and further, a shape of a central portion of the rolled material can be controlled at least to the concave crown side. Using at least four stages of cold rolling mills provided with two-shape control means and a shape detector for measuring at least the shape of the plate after rolling, a local roll diameter gradually increasing region of the pair of upper and lower work rolls before rolling is used. And the moving position of the pair of upper and lower work rolls by the shift device is set so that the end of the plate wraps. During rolling, the shift position of the pair of upper and lower work rolls is substantially fixed, and according to the output of the shape detector. In this case, the operation amounts of the first and second shape control means are determined so that the effects on the respective shapes act in opposite directions.

Thus, as described in the above (1), the change in the thermal crown during rolling is controlled by the first shape control means, and the change in the overall shape of the rolled material, that is, the change in the body crown by the operation of the first shape control means. Can be controlled by the second shape control means, and in cold rolling, there is no problem of scratches or responsiveness on the surface of the rolled material, and it is possible to appropriately cope with a change in the thermal crown that changes every moment during rolling,
In addition, rolling can be performed without deteriorating the overall plate shape.

(15) In the above (14), preferably, the operation amount of the first shape control means is determined according to the shape output near the plate edge by the shape detector, and the operation amount of the second shape control means is determined. The operation amount is determined according to the shape output near the center of the plate by the shape detector.

As a result, the target values of the operation amounts by the first and second shape control means can be clearly distinguished, and the actual control method can be easily understood and simplified.

(16) In order to achieve the above object, a rolling method according to the present invention comprises a first shift device which enables a pair of upper and lower work rolls to move in opposite directions, and a pair of the upper and lower work rolls. A second shift device that enables the pair of upper and lower intermediate rolls to be supported to be movable in opposite directions, wherein the pair of upper and lower work rolls has a local roll diameter gradually increasing portion that is tapered at one of respective roll ends. And six-stage cold rolling, wherein the local roll diameter gradually increasing portion is arranged so as to be symmetrical with respect to the upper and lower points, and has shape control means capable of controlling the shape of the central portion of the rolled material at least to the concave crown side. Machine, and a shape detector for measuring at least the shape of the plate after rolling, the first shift device so that the local roll diameter gradually increasing region of the pair of upper and lower work rolls and the plate end overlap before rolling. By The moving positions of the pair of upper and lower work rolls are set, and the shift positions of the pair of upper and lower work rolls are substantially fixed during rolling, and the operation amounts of the second shift device and the shape control means according to the output of the shape detector. Are determined such that the effects on the respective shapes act in opposite directions.

Thus, as described in (1) above, the change in the thermal crown during rolling is controlled by the first shape control means, and the change in the overall shape of the rolled material, that is, the change in the body crown, by the operation of the first shape control means. Can be controlled by the second shape control means, and in cold rolling, there is no problem of scratches or responsiveness on the surface of the rolled material, and it is possible to appropriately cope with a change in the thermal crown that changes every moment during rolling,
In addition, rolling can be performed without deteriorating the overall plate shape.

(17) In the above (16), preferably, the operation amount of the second shift device is determined according to the shape output near the plate edge by the shape detector, and the operation amount of the shape control means is preferably The determination is made according to the shape output near the center of the plate by the shape detector.

As a result, the target values of the operation amounts by the first and second shape control means can be clearly distinguished, and the actual control method can be easily understood and simplified.

[0051]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a six-high rolling mill (cold rolling mill) according to an embodiment of the present invention, and FIGS.
1 shows a sectional view taken along the line II-II and III-III in FIG.

In FIG. 1 to FIG. 3, the six-high rolling mill reinforces a work roll 2 which directly contacts and rolls a rolled material 1, an intermediate roll 3 which is in contact therewith, and a reinforcing roll 4 which is in contact with the intermediate roll 3. The structure is such that it is supported by the housing 5 via the bearing box 6 of the roll 4. A hydraulic jack 7 is installed at a lower portion of the housing 5, and thereby a lower reinforcing roll 4 is provided.
The rolling material 1 is lowered by moving the bearing box 6 up and down. Bearing boxes 8 and 9 are attached to the roll ends of the work roll 2 and the intermediate roll 3, and as shown in FIG.
Hydraulic cylinders 10a, 10b and 11a, 1 which flex each roll by applying a force to these bearing boxes
1b is installed. In particular, in the following, a hydraulic cylinder 10a that bends in a direction to enlarge the gap of the work roll 2
And 11a are called an increase bending device (increase bender), and the hydraulic cylinders 10b and 11b that bend in the opposite direction are called a decrease bending device (decrease bender).

The work roll 2 and the intermediate roll 3 are
A roll shift device is provided so as to be movable in the axial direction. An example of the shift device will be described with reference to FIG. 3 taking a work roll as an example. In FIG. 3, a shift support member 12 for supporting the bearing box 8 of the work roll 2 and a shift head 13 connected thereto are provided.
3 is provided with a shift attaching / detaching device including a hook 14 and a connecting cylinder 15 for freely connecting to the work roll bearing box 8 on one side. Further, the shift head 13 has a structure in which a shift cylinder 16 fixed to the housing 9 is connected. By doing this,
The work roll 2 and the shift support member 12 can be moved to any position by operating the shift cylinder 16 with the shift attaching / detaching device attached. The shift support member 12 includes the bending device 10.
a, 10b and 11a, 11b are built in, so that even if the work roll 2 is shifted, the point of action of the bending force does not change, and a large shift stroke can be taken.

The shift device for the intermediate roll 3 can be formed in a similar structure, and is not shown.

The work roll 2 of the six-high rolling mill as described above has a local roll diameter gradually increasing portion which gradually becomes thicker toward one end on one side, that is, a local concave crown 2a.
Are arranged so that they are vertically symmetrical, and a shift device as shown in FIG. 3 is installed, and these are moved upside down. The local concave crown 2a is for controlling the thermal crown generated in the work roll 2, and the applied crown length of the local concave crown 2a is substantially equal to the thermal influence length (described later) of the thermal crown. , And more preferably. Therefore, generally, a crown length of about 100 to 300 mm is provided. Further, the concave crown shape is desirably a shape that cancels out the thermal crown of the roll.
A subcurve shape is sufficient. Although the compatibility with the thermal crown shape is slightly deteriorated, it is also possible to form the taper shape so that roll grinding is easy. Furthermore, the above-mentioned concave crown amount may be appropriately determined based on actual rolling conditions and actual results, and is usually set to a crown amount sufficient to control the maximum thermal crown generated in actual rolling, and a shift device is used according to various rolling conditions. The rolling may be performed by setting an appropriate work roll position.

Further, at the end of the intermediate roll 3, a local roll diameter gradually decreasing portion, that is, a local convex crown 3a having substantially the same curvature as the local concave crown 2a provided to the work roll 2 is provided. . This is to reduce the contact surface pressure between the rolls, that is, the contact surface pressure between the intermediate roll 3 and the work roll 2 and between the intermediate roll 3 and the reinforcing roll 4. Thereby, since spalling and uneven wear of the roll, which are likely to occur at the end of the roll, can be suppressed, it is possible to achieve a longer roll life.

Next, in order to clarify the following description, characteristics of the thermal crown will be clarified. FIG. 4 schematically shows the shape R of the thermal crown generated on the work roll with the center of the rolled material 1 as the origin. As shown in this figure, the thermal crown R generally caused by the change in the thermal expansion of the roll has a profile that gradually changes from the center of the plate indicated by S to a position just before the end E of the plate. It changes sharply before and after the end E, and then gradually changes again in the T portion up to the roll end. Here, the gradual change in the portion S in the figure can be sufficiently controlled by a roll bender or the like conventionally used,
There is no particular problem. Further, since the b and T portions are changes at positions off the rolled material, they also can be ignored since they do not directly affect the shape of the rolled material. Therefore, the essential part in the control of the thermal crown is the remaining part a, and the substantial thermal crown amount affecting the rolled material is Cs shown in FIG. However, when the amount of thermal crown is usually expressed, the roll end is often taken as a reference. Therefore, in the following description, it is expressed by Ch shown in the drawing, and the relationship between Cs and Ch is generally considered as Ch = 2Cs. And In the following, the distance from the edge of the plate to the portion a is referred to as a thermally affected length. The length of this thermal effect is determined by the rolling time,
It depends on rolling conditions, coolant control method, etc.
The above-mentioned document "Plasticity and processing, vol.23 no.263 (1982-1
2)), about 100
It is about 300 mm. It is apparent from this figure that when rolling is performed using a work roll in which such a thermal crown has been generated, a so-called edge-up shape in which the plate thickness rapidly increases near the plate edge.

The present invention controls such a thermal crown. For this purpose, a local concave crown 2a is first provided to the roll end of the work roll 2 as described above.

In the present invention, the local concave crown 2a
In addition to the above, the work roll 2 is used in combination with the local concave crown 2a.
First shape control means for controlling the thermal crown formed on the rolled material, and second shape control means for controlling the shape of the central portion of the strip width of the rolled material 1 to at least the concave crown side,
In this embodiment, a decrees bending device (decrease bender) 1 acting as a first shape control means in a direction to reduce a gap between a pair of upper and lower work rolls 2a.
0b, and an increase bending device (increase bender) 11a for controlling the bending of the pair of upper and lower intermediate rolls 3 is provided as second shape control means.

The outline of the rolling method performed by using the rolling mill according to the present embodiment is as follows.

When the thermal crown is controlled by the work roll 2 having the local concave crown 2a at the roll end, the shift position of the work roll 2 is appropriately set according to the state of the generated thermal crown. However, it is generally very difficult to directly detect the thermal crown of the work roll 2 with high precision during rolling. Therefore, a shape detector is installed on the exit side of the rolling mill (see FIGS. 19 and 20). Indirect detection and control are performed by the output of the detector. Further, shifting the work roll 2 during rolling is not so good especially in aluminum rolling. Therefore, at the time of non-rolling such as when switching the rolling coil,
Alternatively, it is desirable to set an appropriate position at the time of low-speed rolling at the time of switching the rolling pass. Thereby, work roll 2
The effect of the thermal crown generated at the time can be directly reduced by the effect of the local concave crown.

However, the thermal crown of the work roll 2 changes every moment. For this, work roll 2
Using a work roll bender for controlling the bending of the rolls, in particular, a first shape control means of the decreise bender 10b, and a second shape control means for controlling the rolled material 1 in the concave crown direction (increase bender 11a of the intermediate roll 3). Perform rolling. The point of this rolling method is that, for example, the first shape control means is moved in the
Rolling while controlling the shape control means in the increment direction so as to be in the opposite direction to the action on the rolled material. Naturally, if the thermal crown decreases due to the effect of roll coolant control, the first
It goes without saying that the shape control means is controlled in the increase direction and the second shape control means is controlled in the decrese direction. The object of the present invention is to provide a compensation control by applying a change in the shape of the central portion of the plate caused by operating the first shape control means in a direction opposite to the operation of the first shape control means by the operation amount of the second shape control means. Is to do. Thereby, even if the first shape control means is operated, the shape of the rolled material is not largely disturbed, and it is possible to perform rolling while maintaining a good shape. In particular,
The operation amount of the first shape control means is mainly determined according to the shape output near the plate edge, and the operation amount of the second shape control means is determined according to the shape output near the plate center. , First
And the target value of the operation amount by the second shape control means can be clearly separated. This has the effect of making the actual control method very easy to understand and simple. Further, in order to make the above control more effective, it is preferable to use the working roll diameter in the range shown by the following expression (3).

An example of simulating the shape control characteristics of the thermal crown in the above rolling mill using the calculation conditions shown in Table 1 will be described below. However, the board width is 12
00 mm.

[0065]

[Table 1]

FIG. 5 is an explanatory diagram of the dimensions of the local roll crown provided to the intermediate roll and the end of the work roll in this embodiment, and the roll shift positions. In the figure, the distances Lcw, Lci from the roll ends of the work roll 2 and the intermediate roll 3 to the crown start point are respectively equal to 168 m.
m, and the roll crown amounts Cw and Ci are 40
μ was given. In addition, the shift position of each roll uses the distance from the plate end to the roll end with reference to the plate end of the rolled material 1,
They are represented by δw and δi, respectively.

FIG. 6 shows the shape of the thermal crown used in this simulation. Curve A in FIG.
B and C have thermal crown amounts of 60, 50 and 40, respectively.
μ, and the thermal influence length was assumed to be about 175 mm.

FIG. 7 shows the results of a simulation performed on a 6-high rolling mill using a straight roll having no thermal crown and the above-mentioned thermal crown. The horizontal axis in FIG. 7 shows the position coordinates (mm) in the sheet width direction with the center of the sheet as the origin, and the vertical axis shows the exit side sheet thickness distribution (mm) after rolling. However, the calculation condition is δi = 0, and the work roll bender Fw and the intermediate roll bender Fi have a substantially straight (flat) plate crown (body crown) near the center of the plate width.
Fw = −18 ton (negative represents the Decrease vendor) and Fi = 68 ton so that Symbols A, B, and C in the figure represent the thermal crowns of 60 and 5, respectively.
The case where 0,40μ is given is shown.

As is clear from FIG. 7, in each case, a sharp increase in the plate thickness is observed near the plate edge, and it is understood that the plate has an edge-up shape (for example, EA of case A). Furthermore, in the vicinity of the edge-up start (end 2 indicated by ES),
Once the plate thickness has suddenly decreased. In this case, the so-called end No. 2 extension locally extending at end No. 2 near the end of the plate causes an internal tension of tension to act on the edge of the edge-up plate. In addition to this, the tension acting as an external force from the winder or the like acts strongly near the edge of the edge-up portion and is added. As a result, even in cold reversible rolling of general carbon steel sheets, 0.3 m
As described above, in the case of a thin plate having a thickness of about m, and particularly in the case of rolling aluminum or copper as a soft material, the risk of plate breakage increases significantly, causing various problems.

Whether or not the above-described shape can be improved only by adjusting the bending force will be examined. Here, the effect of the intermediate roll bender Fi on the plate is effective over the entire width of the plate and is therefore effective for controlling the body crown. Not valid for Therefore, here, a simulation result when only the work roll bender Fw is changed is shown in FIG. FIG. 8 shows the characteristic B of FIG.
Curve a is F
w is increased by 2 tons to -14 tons, and curve b is decreased by 4 tons to -22 tons. For curve a, F
By increasing w, the edge No. 2 elongation is reduced, but the edge-up shape is increased. Therefore, Fw
It can be seen that even if the value is increased, the shape and the tension distribution cannot be improved. Conversely, when Fw is reduced, the edge-up shape is slightly improved, but the overall shape of the body crown becomes a large convex crown shape, and the shape is greatly deteriorated.

As described above, it can be said that it is very difficult to control a local shape generated near the plate edge by using only a normal roll bender.

Next, FIG. 9 shows an example of a simulation result in the case where a local concave crown and a convex crown are respectively applied to the end of the work roll and the intermediate roll in the above-mentioned specification. In this case, the shift position of each roll is δw = 1
4 mm, δi = 0 mm. The symbols A,
B and C are respectively 60, 50 and 40 μm thermal crowns.
Indicates when given. However, each roll bending force is appropriately adjusted to a value that makes the shape good.

As is apparent from a comparison between FIG. 9 and FIG. 7, it can be seen that the edge-up shape due to the problematic thermal crown is significantly improved. Therefore, by applying such a rolling mill, particularly to a cold reversible rolling mill, or a rolling mill for soft materials such as aluminum and copper,
It is understood that the present invention exerts tremendous effects on the improvement of rolling operability, yield, quality and the like.

Next, the effect of giving a locally convex crown to the end of the intermediate roll 3 will be described with reference to FIG. FIG.
Are the case where a locally convex crown is given to the intermediate roll 3,
This is a comparison of the contact linear pressure distribution between the rolls when no roll is applied, and the thermal crown amount is 50 μm. In addition, the symbol Q in the figure shows the contact linear pressure distribution between the work roll 2 and the intermediate roll 3, and R shows the contact linear pressure distribution between the intermediate roll 3 and the reinforcing roll 4. However, each roll bending force is slightly changed in order to make the exit side plate crown shape substantially the same as the characteristic B in FIG. For reference, the plate crown shape S obtained at this time is also shown.

As is clear from FIG. 10, the peak of the linear pressure distribution at the roll end indicated by the symbol D is greatly reduced when a local convex crown is provided. Thus, it can be seen that by giving a locally convex crown to the end of the intermediate roll 3, it is possible to suppress uneven wear of each roll and to extend the life of the roll. However, the obtained shapes are almost the same in both cases, and it is clear from the shape control characteristics of the thermal crown that the locally convex crown of the intermediate roll 3 is not a necessary absolute condition. For example, in the case where the rolling load is small and the contact surface pressure between the rolls does not matter, the local convex crown of the intermediate roll 3 may not be provided.

It goes without saying that the thermal crown changes every moment even if it is rolled in the same coil. For example, when rolling is performed while keeping conditions such as coolant control constant, the amount of thermal crown changes in a direction that gradually increases. On the other hand, when rolling is performed using the work roll 2 provided with the locally concave crown, it is conceivable that the position of the work roll 2 is changed and controlled every moment according to the amount of generation of the thermal crown. However, moving the work roll 2 during rolling has a risk of causing scratches on the surface of the rolled material, and is not satisfactory in cold rolling equipment, particularly rolling of a soft material such as aluminum. Although it is possible to cope with this with coolant control, the response is slow and it is hard to say that it is ideal.

Therefore, in the present invention, a change in the thermal crown during rolling is handled by roll bender control. In this case, as is clear from FIG. 9, as the thermal crown amount increases, the work roll bender moves to the decrese side, the intermediate roll bender moves to the increase side, and
It is necessary to control each of them to increase in the opposite direction. On the other hand, if the local concave crown amount given to the work roll 2 is increased, the work roll bender can be controlled on the increase side, but at this time, there is a disadvantage that the edge drop amount increases. Therefore, it is desirable that the amount of the local concave crown be as small as possible. In this case, the combined control of the local concave crown and the decreise bender greatly contributes to the improvement of the yield in contrast to the control of the thermal crown.

Further, when the combined control with the roll bender is performed, there is an effect that the position setting accuracy of the work roll 2 can be reduced. In order to show this, the result of simulating the relationship between the set shift position and the shape control characteristic is shown in FIG.
It is shown in FIG. The calculation conditions were the same as those in Table 1, and the thermal crown amount was 50 μm. Curves A, B, and C in FIG.
The exit side plate thickness distributions when δw = 0, 14, and 28 mm, respectively, and the work roll and the intermediate roll bending force were adjusted to obtain favorable shapes are shown.

As is clear from FIG.
Even if the setting position is appropriately changed, the work roll and the intermediate roll bending force are controlled to obtain a good shape in any case. Conversely, if the control is performed in combination with the work roll and the intermediate roll bender, it means that the set position of the work roll can be roughened. Therefore,
The above-mentioned effect on the combined control of both is apparent from this, and it can be said that the shift position setting control of the work roll 2 can be remarkably simplified.

However, when controlling the thermal crown in combination with the bender as described above, the selection of the work roll diameter in particular has an essentially important meaning. That is, when the sheet crown generated by the thermal crown is approximated by a polynomial of a power function, it is generally expressed as a higher-order component of a fourth-order equation or higher. Therefore, it is preferable that the characteristic exerted on the sheet crown of the work roll has a high-order component as large as possible. This means that the smaller the work roll diameter, the better.
However, if the work roll diameter is very small, the effect of the roll bender acts only on a very limited portion near the plate edge that is less than the thermal influence length of the thermal crown. It can be said that there is no effect on the control of. Furthermore, work roll drive is desirable in order to perform rolling stably, but there are drawbacks such as not being possible in the case of a small diameter. This is one of the points to be particularly careful when planning a cold reversible rolling mill for rolling soft materials such as aluminum and copper, which are particularly difficult to operate. In addition, when the diameter of the work roll is small, the plate crown generated by the work roll bender generally shows complicated characteristics, and there is a problem that shape control becomes difficult. Conversely, when the diameter is large, the effect of the work roll bender on the sheet crown is dominated by low-order components. For this reason, when trying to control the thermal crown, it greatly changes to the body crown, and it cannot be said that effective control can be realized.

From the above, it can be seen that when the thermal crown is controlled by using the work roll with the locally concave crown and the work roll bender together, there is an appropriate working roll diameter usage range. This will be described below with reference to FIG.

FIG. 12 shows the work roll diameter on the horizontal axis and the higher-order component ratio r of the sheet crown on the vertical axis in order to examine the characteristics of the work roll decrease bender on the sheet crown. Here, the high-order component ratio r of the sheet crown is defined as x, where x is a coordinate obtained by standardizing the left and right sheet edges at ± 1 with respect to the center of the rolling mill, and δFw changes the work roll bending force. the change amount is DerutaCw, with fourth-order polynomial this, the coefficients a _2, a ₄ in the case of optimal approximation ^{_{δC W = a 4 x 4 +}} a 2 x 2 ... (1), r = a 4 / (A ₂ + a ₄ )... (2) That is, the ratio of the higher-order component (a ₄ ) to the total change amount (a ₄ + a ₂ ) of the sheet crown generated at the sheet edge due to the change in δFW. The effect of the component is large, and it can be said that it is suitable for controlling the thermal crown. Also, curves A, B, and C in FIG.
In the case of 1500 and 1800 mm, the roll surface length at this time was 1420, 1720 and 2020 mm, respectively, and the rolling load was calculated at a linear pressure of 0.5 t / mm.

As is apparent from FIG. 12, even when the roll diameter is larger than the roll diameter indicated by a in the figure, the higher-order component suitable for controlling the thermal crown hardly changes. And the rolling mill becomes large, and the production cost increases. Therefore, in order to effectively control the thermal crown, it can be said that it is particularly preferable that the diameter is equal to or less than the work roll diameter indicated by a in FIG.

Further, when the work roll diameter is small, the higher-order component ratio r of the sheet crown is 1 or more. FIG. 13 shows a calculation example of the change δCw of the plate crown in this case. FIG. 13 shows a work roll diameter of 200 and a maximum slope width of 1
This is a calculation example when the distance is set to 200 mm, and the solid line represents an approximate curve calculated by a recent expression (described in the figure) of δCw. It can be seen from FIG. 13 that when the diameter becomes such a small value, the change δCw of δFw exerted on the plate crown has a complicated characteristic of being concave at the plate center. As a result, the approximate expression of the change amount δCw of the plate crown is approximated so that the signs of the fourth-order and second-order coefficients are different, and as a result, the higher-order component ratio r becomes 1 or more. Therefore, increasing the number of work roll benders in the decreasing direction in a rolling mill having such characteristics has the effect of reducing the plate thickness at the plate edge, but it is as if an increase bender acted on the plate center. Effects are exhibited, and extremely complicated characteristics are exhibited. This means that the actual shape control becomes complicated, which is not good. Accordingly, it is desirable that the work roll diameter is selected such that the higher-order component ratio r is 1 or less.

Further, in practice, the roll diameter on the smaller diameter side is not determined only from the shape control characteristics described above, but it is natural that the roll diameter is set such that the required rolling torque can be transmitted.

As described above, the range of the work roll diameter suitable for controlling the thermal crown by using the local concave crown roll and the roll bender together is shown in FIG. That is, if the above relationship is expressed by an equation, it is understood that the working roll diameter Dw is extremely suitable in the range of 1 / 6Wm + 50 ≦ Dw ≦ 1 / 6Wm + 250 (3) using the maximum usable plate width Wm.

According to the present embodiment, the cold rolling does not cause any damage on the surface of the rolled material or the problem of responsiveness, and can appropriately cope with the change of the thermal crown that changes every moment during rolling. Thus, the thermal crown can be controlled without deteriorating the plate shape, and a high-quality cold-rolled product can be stably manufactured.

Next, an embodiment using another type of rolling mill having the same effect will be described.

FIG. 15 shows an embodiment of the same six-stage mill, in which a work roll 2 having a locally concave crown at one end so as to be movable in the lateral direction is arranged symmetrically in the vertical direction. The intermediate roll 3 which can be moved in the horizontal direction is a straight roll. When the thermal crown is controlled by this rolling mill, the set position of the work roll 2 is controlled such that one end of the rolled material 1 is located at the locally concave crown 2a of the work roll 2. Conversely, the intermediate roll 3 is rolled with its roll end placed near the other end of the rolled material 1. Naturally, upper and lower work rolls 2 and intermediate rolls 3
Are controlled and arranged approximately symmetrically with respect to points.

When such a rolling mill is used, the thermal crown can be suitably controlled at the local concave crown 2a of the work roll 2 and also in combination with a work roll bender, especially a drease bender. It is clear from the above explanation. However, since the intermediate roll 3 is not provided with the relief of the locally concave crown 2a of the work roll 2,
There is a disadvantage that the contact linear pressure between the two becomes large. However, using this type of rolling mill for thermal crown control has another merit.

That is, even if there is no thermal crown, in order to control the plate shape generated mainly due to the deflection of the roll system of the reinforcing roll 4 or the like, a basic bender force (basic intermediate roll bender force) is applied to the intermediate roll. ) Is required.
On the other hand, by using a rolling mill as shown in FIG.
The contact width between the work roll 2 and the intermediate roll 3 can be set substantially equal to the plate width. That is, the load width of the distributed load generated between the work roll 2 and the intermediate roll 3 can be made substantially equal to the plate width, and no extra external force acts on the work roll 2 outside the plate width. This means that the amount of deflection of the work roll 2 is reduced. This reduces the required basic intermediate roll bender force and reduces the intermediate roll 3
It can be understood that there is an effect of reducing the contact linear pressure generated by the intermediate roll bender between the end of the reinforcing roll 4 and the reinforcing roll 4.

In the description of FIG. 9, it has been described that the intermediate roll bender force increases in the increase direction as the thermal crown amount increases. If this intermediate roll bender force is a value obtained by adding the basic intermediate roll bender force, when the thermal crown is controlled by using the local concave crown roll and the roll bending device together, this structure is adopted. The effect of using a rolling mill is obvious. In particular, when the range of the strip width to be rolled is wide, for example, when the minimum used strip width reaches 0.4 to 0.3 of the maximum strip width, it can be said to be effective when rolling the rolled material on the narrow width side. .

In the above embodiment, the intermediate roll 3 which can be moved in the lateral direction and the local concave crown 2 at the roll end are used.
The six-high rolling mill including the work rolls 2 having a has been described. He also stated that combined use control with a roll bender is effective for changing the thermal crown during rolling. The essence of the thermal crown control using the bender control in such a six-high rolling mill is essentially a work roll bender which is first shape control means suitable for controlling a thermal crown generated in the work roll 2, a reinforcing roll 4, and the like. In other words, it has a suitable second shape control means for controlling the plate shape generated mainly based on the bending of the roll system. That is, the first shape control means is used on the decreise side for thermal crown control, and the resulting body crown in the convex crown direction is increased by the second shape control means in the increase direction, so that the overall shape is reduced. That is, control is performed so as to be flat.

There is another method for rolling the thermal crown which changes every moment during rolling. That is, FIG.
In the six-high rolling mill having the movable intermediate roll 3 shown in (1), the work roll bender (first shape control means) is not controlled together with the change of the thermal crown during rolling, but the intermediate roll 3 is moved to the plate edge. Shift away from the outside. This causes the end of the intermediate roll 3 to press the local concave crown at the end of the work roll 2, so that local bending deformation can be applied to the end of the work roll 2, and only the plate end is further reduced. can do. If the intermediate roll 3 is shifted in the reverse direction, it is natural that the reduction of the plate end can be reduced. Even in this case, it is not necessary to shift the work roll 2 during rolling, so that there is little risk of damaging the plate surface, and effective control can be performed on the ever-changing thermal crown.

In the above embodiment, the second shape control means in the six-high rolling mill is an intermediate roll bender. However, for the second shape control means, the following various methods can be applied.

FIG. 16 shows an embodiment in a cross-shift type four-high rolling mill. In this rolling mill, the work roll 2
Is equipped with a shift device capable of moving in the horizontal direction and a cross device capable of rotating in the horizontal direction with respect to the center of the rolling mill.
What is necessary is just to make it the structure as disclosed in -60310 gazette.

[0097] A local concave crown is added to the end of the work roll 2, and at least both a decrease vendor and preferably an increase vendor are provided as first shape control means. Further, by crossing the work rolls 2, the amount of the gap (roll gap) between the upper and lower work rolls 2 can be variably controlled in a substantially quadratic curve in the plate width direction, which is effective for controlling the body crown. It is known. Therefore, in this case, the second shape control means corresponds to the cross device of the work roll 2. FIG. 16 shows an example in which the work rolls 2 are crossed. However, the same applies when only the reinforcing rolls 4 or a cross device that crosses the work rolls 2 and the reinforcement rolls 4 simultaneously is used as the second shape control means. It is obvious that the effect is obtained. Further, JP-A-10-235412
, A six-high rolling mill having an intermediate roll provided with a cross device as disclosed in JP-A-2000-33405, the intermediate roll cloth device may be used as the second shape control means. Becomes

FIG. 17 shows another embodiment of a six-high rolling mill. The work roll 2 is provided with a local concave crown at the end of the roll so that the work roll 2 can be moved, and at least a decrease vendor, preferably an increase vendor. Provide both, this is the first
It is a shape control means. The intermediate roll 3 has, for example, a cubic curve roll profile having both a maximum and a minimum, and has a second shape control means that is movable. It is well known that by shifting the intermediate roll 3 using such second shape control means, the gap between the upper and lower work rolls 1 can be variably controlled substantially in a quadratic curve, which is effective for controlling the body crown. It is. However, the second shape control means has little effect on the control of a locally generated shape of the plate edge such as a thermal crown, and therefore requires the first shape control means.

FIG. 18 shows another embodiment of a four-high rolling mill, in which a work roll 2 is provided with a local concave crown at the roll end so as to be movable, and at least a Decrease vendor, preferably an increase vendor. Provide both, this is the first
It is a shape control means. The reinforcing roll 4 provides a convex crown that gradually tapers from substantially the center of the roll toward one roll end, and is provided with a shift device that can move the convex crown. It is well known that by shifting such a reinforcing roll 4 in the up-down direction, the gap between the upper and lower work rolls 1 can be variably controlled substantially in a quadratic curve, which is effective for controlling the body crown. For example, a work roll provided with the roll crown and shift device is disclosed in Japanese Patent No.
865804. In this case, the second
The shape control means corresponds to a shift device of the reinforcing roll 4. In such a rolling mill, it is desirable to provide the convex crown of the reinforcing roll 4 on the side of the locally concave crown provided to the work roll 2. In this way, the contact surface pressure generated between the work roll 2 and the reinforcing roll 4 can be reduced,
The effect of suppressing the uneven wear of the roll is apparent from the above description of the six-stage mill.

FIG. 19 shows an embodiment in which the above rolling mill is applied to a reversible rolling mill for steel sheets. In this example, a tension reel 19, a pinch roll 20, a shape detector 21, and a drainer 22 are arranged one by one on the left and right of the rolling mill 17. Further, on one side, a payoff reel 1 for inserting and unwinding the first rolled material (coil) 1.
8 and a pinch roll 20 are provided. On both sides of the rolling mill 17, a roll cooling header 23 and a rolling lubrication header 24 are provided. Here, since the rolled material 1 is taken up and rewound between the tension reels 19 on both sides and repeatedly rolled while changing the direction, in the following description, the entry side and the exit side will be referred to It means the side where the rolled material 1 after the rolling is present.

At first, the rolled material 1 is set on a payoff reel 18 and guided by a pinch roll 20 while being pressed.
The sheet is passed through a rolling mill 17. In the rolling mill 17, the fluid is supplied from the coolant header 23 and the rolling lubrication header 24 to the work roll 2 and a contact portion (roll bite) between the work roll 2 and the rolled material 1, and the rolled material 1 is cooled while performing roll cooling and rolling lubrication. It is rolled and wound up on the output side tension reel 19. In the following, since the same oil type is usually used for the roll coolant and the rolling lubricant, they are collectively referred to as a coolant (oil) without distinction between them. The coolant oil is rolled without being supplied from the spray headers 23 and 24 on the outlet side. This is because, if coolant oil remains on the surface of the rolled material 1, slippage easily occurs between the layers of the output side tension reel 19, and the risk of winding collapse and misalignment is significantly increased. That's why. In the present embodiment, a drainer 22 is provided to ensure the removal of the coolant oil. However, even in this case, it is difficult to completely remove the coolant oil, and when the rolled material 1 has an edge-up shape due to the thermal crown, the above-described danger increases as described above. Moreover, in the cold reversible rolling facility, the rolled material 1 is repeatedly rolled a plurality of times while changing the rolling direction on the entrance and exit tension reels 19, so that the number of windings increases.
It can be said that the risk increases. Therefore, the rolled material 1
When a large edge-up shape is detected by the shape detector 21 installed on the exit side of the above, a careful operation such as lowering the rolling speed is usually performed.

As described above, in particular, controlling the thermal crown using the rolling mill according to the present invention in a cold reversible rolling facility has a particularly remarkable effect on the improvement of the product surface quality, yield, and productivity. Was understood.

FIG. 20 shows an embodiment applied to an aluminum rolling facility. In the aluminum rolling equipment, the tension reel 19 is usually installed only on the outgoing side, and the payoff reel 18 is installed on the incoming side. This is because, unlike the reversible rolling of general carbon steel sheets, a rolling method called so-called one-way rolling is employed. In one-way rolling,
This is a rolling method in which about several tens of coils are generally managed as one lot, and rolling is performed repeatedly in lot units. Therefore, each coil in the lot is sequentially set on the payoff reel 18 and rolled only once while being wound on the tension reel 19. This is repeated a plurality of times for each lot, and rolling is performed until the final sheet thickness is reached. As described above, since the rolling in the reverse direction from the tension reel 19 to the payoff reel 18 is not performed, the inlet-side shape detector 21 and the outlet-side coolant headers 23 and 24 are unnecessary.

As described above, in the aluminum rolling equipment, since a one-way rolling method is usually employed, the leading and trailing ends of the rolled material 1 always include a portion to be rolled without tension in each pass of rolling. In the above-mentioned tensionless state, meandering tends to occur at the front and rear ends of the rolled material 1, making the rolling difficult. This tendency is particularly pronounced as the product is closer to the final product and thinner. In such rolling, it is desirable to eliminate as much as possible a factor such as a thermal crown that causes disturbance to the rolling. In this sense, it can be said that in the case of aluminum rolling, it is important to apply the shoring machine according to the present invention, which has remarkably high controllability to the thermal crown.

Also, it has already been described that in the aluminum rolling equipment, a flammable coolant oil having a low flash point is usually used, so that a fire is likely to be caused by a rupture of the plate. It has been repeatedly pointed out that one of the major causes of the plate breakage is an edge-up shape caused by the thermal crown. In particular, when rolling a soft material such as aluminum, it can be said that the influence of the thermal crown appears remarkably on the shape, and that the plate is easily broken. On the other hand, although not shown in FIG. 18, a large-scale digestion facility is installed around the ordinary rolling mill 17. However, once a fire occurs, even if the fire extinguisher is activated immediately, the oil seals, flexible hoses, wiring, etc. installed on each machine part are unavoidable, requiring large repair costs and repair periods. Will be done. In this way, it can be said that controlling the thermal crown particularly effectively in the aluminum rolling equipment greatly reduces the frequency of serious accidents such as fires and contributes to improvement of operability and productivity. .

[0106]

According to the present invention, the cold rolling does not cause any damage on the surface of the rolled material or the problem of responsiveness, and can appropriately cope with the change of the thermal crown which changes every moment during rolling. And a high-quality cold-rolled product can be stably manufactured without deteriorating the plate shape.

[Brief description of the drawings]

FIG. 1 shows a side view of a six-high rolling mill (cold rolling mill) according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a diagram schematically showing a shape of a thermal crown generated on a work roll with the center of a rolled material as an origin.

FIG. 5 is an explanatory view of dimensions of a local roll crown provided to an intermediate roll and a work roll end in the present invention and respective roll shift positions.

FIG. 6 is a diagram showing a shape of a thermal crown used in a simulation.

FIG. 7 is a diagram showing a simulation result of a 6-high rolling mill using a straight roll provided with a thermal crown and having no local roll crown.

FIG. 8 is a diagram illustrating a simulation result when only the work roll bender Fw is changed.

FIG. 9 is a diagram showing a simulation result in a case where a local concave crown and a convex crown are respectively provided to a work roll and an intermediate roll end.

FIG. 10 is a diagram showing an effect of giving a locally convex crown to an end of an intermediate roll.

FIG. 11 shows a case where combined control with a roll vendor is performed.
FIG. 9 is a diagram illustrating a result of simulating a relationship between a set shift position and a shape control characteristic in order to explain an effect that a position setting accuracy of a work roll can be roughened.

FIG. 12 is an explanatory diagram of a higher-order component ratio affecting a sheet crown of a work roll bender.

FIG. 13 is a diagram showing a calculation example of a change δCw of a sheet crown when the work roll diameter is set to be small.

FIG. 14 is a view collectively showing a range of a work roll diameter suitable for controlling a thermal crown by using a locally concave crown roll and a roll bender.

FIG. 15 is a view showing another embodiment of the six-high rolling mill of the present invention.

FIG. 16 is a diagram showing an embodiment in which the present invention is applied to a cross-shift type four-high rolling mill.

FIG. 17 is a view showing still another embodiment of the six-high rolling mill of the present invention.

FIG. 18 is a view showing another embodiment of the four-high rolling mill of the present invention.

FIG. 19 is a view showing an embodiment in which the cold rolling mill of the present invention is applied to a reversible rolling facility for steel sheets.

FIG. 20 is a diagram showing an embodiment in which the cold rolling mill of the present invention is applied to an aluminum rolling facility.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolled material 2 Work roll 3 Intermediate roll 4 Reinforcement roll 5 Mill housing 6 Reinforcement roll bearing box 7 Hydraulic pressure reduction device 8 Work roll bearing box 9 Intermediate roll bearing box 10 Work roll bending device 11 Intermediate roll bending device 12 Shift support member 13 Shift Head 14 Shift hook 15 Coupling cylinder 16 Shift cylinder 17 Rolling machine 18 Payoff reel 19 Tension reel 20 Pinch roll 21 Shape detector 22 Drainer 23 Roll cooling header 24 Rolling lubrication header

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21C 51/00 B21C 51/00 L (72) Inventor Tatsuaki Milui 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Yuji Kikuchi 4-6, Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Yasushi Yoshimura 4-6-Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (72) Inventor Shigeichi Yamada 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo F-term in Hitachi, Ltd. (reference) 4E002 AA08 AD04 AD05 BB01 BB13 CA05 4E016 AA02 CA03 CA09 DA14

Claims (17)

[Claims] 1. A cold shift machine comprising at least four stages of cold rolls, comprising: a first shift device for moving a pair of upper and lower work rolls in directions opposite to each other; and a roll bending device for controlling deflection of the pair of upper and lower work rolls. In a rolling mill, a local roll diameter gradually increasing portion which is provided at one of the roll ends of the pair of upper and lower work rolls and is gradually thickened and arranged so as to be vertically symmetrical, First shape control means for controlling a thermal crown formed on each of the pair of upper and lower work rolls in combination with a gradually increasing portion; and a second shape control means for controlling the shape of the central portion of the rolled material at least to the concave crown side. A cold rolling mill comprising shape control means. 2. The cold rolling mill according to claim 1, wherein the roll bending device has a decrease bending device that acts in a direction to reduce a gap between the pair of upper and lower work rolls, and wherein the first shape is the same. A cold rolling mill, wherein the control means is the decrease bending device. 3. The cold rolling mill according to claim 1, wherein the rolling mill is a six-high rolling mill having a pair of upper and lower intermediate rolls and a second shift device capable of moving the intermediate rolls in opposite directions. The cold rolling mill, wherein the first shape control means is the second shift device. 4. A cold rolling mill having at least four or more stages comprising a shift device capable of moving a pair of upper and lower work rolls in opposite directions, and a roll bending device for controlling bending of the pair of upper and lower work rolls. In the pair of upper and lower work rolls has a local roll diameter gradually increasing portion gradually tapered at one of the roll end,
And the local roll diameter gradually increasing portion is arranged so as to be vertically symmetrical, and the roll bending device, as first shape control means, acts in a direction of reducing a gap between the pair of upper and lower work rolls. A cold rolling mill comprising: a bending device; and a second shape control means for controlling a shape of a central portion of the rolled material to at least a concave crown side. 5. A cold reversing rolling equipment comprising a shift device for moving a pair of upper and lower work rolls in directions opposite to each other, and a roll bending device for controlling deflection of the pair of upper and lower work rolls. In at least four or more cold rolling mills, the pair of upper and lower work rolls have a local roll diameter gradually increasing portion gradually tapered at one of the roll ends,
And the local roll diameter gradually increasing part is arranged so as to be vertically symmetrical, and the roll bending device acts as a first shape control means in a direction of decreasing a gap between the pair of upper and lower work rolls. A cold rolling mill comprising: a bending device; and a second shape control means for controlling a shape of a central portion of the rolled material to at least a concave crown side. 6. A cold aluminum rolling facility comprising a shift device for moving a pair of upper and lower work rolls in opposite directions, and a roll bending device for controlling deflection of the pair of upper and lower work rolls. In at least four or more cold rolling mills, the pair of upper and lower work rolls has a local roll diameter gradually increasing portion that gradually becomes thicker at one of the roll ends,
And the local roll diameter gradually increasing portion is arranged so as to be vertically symmetrical, and the roll bending device, as first shape control means, acts in a direction of reducing a gap between the pair of upper and lower work rolls. A cold rolling mill comprising: a bending device; and a second shape control means for controlling a shape of a central portion of the rolled material to at least a concave crown side. 7. The cold rolling mill according to claim 1, wherein the rolling mill is a six-high rolling mill including a pair of upper and lower intermediate rolls movable in an axial direction. A cold rolling mill, wherein the two-shape control means has an increase bending device for controlling the bending of the pair of upper and lower intermediate rolls. 8. A cold rolling mill according to claim 7, wherein said pair of upper and lower intermediate rolls is a local roll diameter gradually increasing portion provided at one of the roll ends and at the roll end of said work roll. On the same side as, has a gradually decreasing tapered local roll diameter portion, the roll diameter change amount of this local roll diameter gradually decreasing portion is approximately equal to the roll diameter change amount of the local roll diameter gradually increasing portion, or A cold rolling mill characterized by being larger. 9. The cold rolling mill according to claim 1, wherein the rolling mill is a six-high rolling mill including a pair of upper and lower intermediate rolls, and the pair of upper and lower intermediate rolls is It has a curved roll crown provided on the entire roll and having both a maximum and a minimum, and the second shape control means has a shift device that can move the pair of upper and lower intermediate rolls in opposite directions. Cold rolling mill. 10. The cold rolling mill according to claim 1, wherein the rolling mill is a six-high rolling mill including a pair of upper and lower intermediate rolls movable in an axial direction. 2. The cold rolling mill according to claim 1, wherein the two-shape control means includes a roll crossing device that inclines at least the pair of upper and lower intermediate rolls with the center of the rolling mill as a substantially rotation center axis in a horizontal direction. 11. The cold rolling mill according to claim 1, wherein the rolling mill is a four-high rolling mill, and the second shape control means includes a pair of the work rolls or a pair of the work rolls. A cold rolling mill having a roll crossing device that tilts one of a pair of upper and lower reinforcing rolls to be supported in a horizontal direction with a center of the rolling mill as a substantially rotation center axis. 12. The cold rolling mill according to claim 1, wherein the rolling mill is a four-high rolling mill, and the pair of reinforcing rolls supporting the work rolls are substantially one-sided from the center of the rolls. A roll crown that tapers toward the end of the roll, and the roll crown is arranged so as to be vertically symmetrical, and the second shape control means moves the pair of upper and lower reinforcing rolls in opposite directions. A cold rolling mill, comprising: a shift device that enables the cold rolling. 13. The cold rolling mill according to claim 1, wherein the working range of the pair of upper and lower work rolls is 1/6 Wm + 50 ≦ Dw ≦ 1/6 Wm + 250 Dw. A cold rolling mill characterized in that the diameter Wm is determined to be the maximum usable sheet width. 14. A shift device for moving a pair of upper and lower work rolls in directions opposite to each other, and a roll bending device for controlling bending of the pair of upper and lower work rolls,
The pair of upper and lower work rolls has a local roll diameter gradually increasing portion that gradually becomes thicker at one of the roll ends,
And the local roll diameter gradually increasing portion is arranged so as to be symmetrical with respect to the upper and lower points, and the roll bending device acts as a first shape control means in a direction of decreasing a gap between the pair of upper and lower work rolls. At least a four-stage cold rolling mill having a bending device, and further provided with a second shape control means capable of controlling the shape of the central portion of the rolled material at least to the concave crown side; Before and after rolling, the position of the pair of upper and lower work rolls by the shift device is set so that the local roll diameter gradually increasing area of the pair of upper and lower work rolls and the plate edge overlap with each other before rolling. During rolling, the shift position of the pair of upper and lower work rolls is substantially fixed, and the amount of operation of the first and second shape control means is changed according to the output of the shape detector. Rolling method characterized by determining to act in effect a reverse on. 15. The rolling method according to claim 14, wherein an operation amount of said first shape control means is determined according to a shape output near a plate end by said shape detector, and said second shape control means is operated. A rolling method characterized in that the amount is determined according to a shape output near the center of the plate by the shape detector. 16. A first shift device for moving a pair of upper and lower work rolls in opposite directions, and a second shift device for moving a pair of upper and lower intermediate rolls supporting the pair of upper and lower work rolls in opposite directions. Device, the pair of upper and lower work rolls have a gradually increasing tapered local roll diameter portion at one of the roll ends, and the local roll diameter gradually increasing portion is vertically symmetrical. Placed in
Using a six-stage cold rolling mill having shape control means capable of controlling the shape of the central part of the rolled material at least to the concave crown side, and a shape detector for measuring at least the shape of the strip after rolling, before rolling The first and second pair of upper and lower work rolls have a local roll diameter gradually increasing region and the first end is overlapped with the plate edge.
The shift position of the pair of upper and lower work rolls is set by a shift device, and the shift position of the pair of upper and lower work rolls is substantially fixed during rolling, and the second shift device and the shape control means are controlled according to the output of the shape detector. The rolling amount is determined so that the effect on each shape acts in the opposite direction. 17. The rolling method according to claim 16, wherein an operation amount of said second shift device is determined according to a shape output near a plate end by said shape detector, and said operation amount of said shape control means is determined by said operation amount. A rolling method characterized in that it is determined according to a shape output in the vicinity of a central portion of a plate by a shape detector.