JP5491090B2 - Rolling mill and tandem rolling mill equipped with the rolling mill - Google Patents

Description

  The present invention relates to a rolling mill capable of reducing the diameter of a work roll and a tandem rolling mill equipped with the rolling mill.

  In a conventional so-called intermediate roll driven six-stage rolling mill (hereinafter referred to as a six-stage mill), the minimum value of the work roll diameter is that there are no support rolls in both the outer and outer widths of the work roll that can be rolled. In this case, the work roll deflection rigidity value withstands the tangential force of the intermediate roll drive is determined. For example, according to Non-Patent Document 1, it is φ180 to φ380 when driven by a 4-width material (4 feet) and an intermediate roll.

  Further, even when the work roll is driven, the tangential force does not work, but the differential tension on the entry and exit sides of the rolling mill works. Therefore, the minimum value of the work roll diameter within the allowable strength range of the drive system is determined by the work roll deflection rigidity value that can withstand the differential tension, and at least a work roll diameter equivalent to that described above is possible. Further, in the case of work roll driving, even in a four-stage rolling mill (hereinafter referred to as a four-stage mill), at least a work roll diameter equivalent to the above can be achieved from this viewpoint.

  Further, as a six-stage mill, there is a conventional one having a support roll within the roll width of the work roll, and further provided with a support bearing outside the roll width of the work roll. Patent Document 1 discloses that a work roll is subjected to horizontal bending.

JP-A-5-50109 JP 2008-126295 A JP-A-60-238021

"Industrial Machinery" May 1991 (pages 56-60)

  By the way, in order to respond to recent needs, when trying to roll a special steel such as a harder stainless steel by a 6-stage mill or a 4-stage mill that does not have a support roll within the width of the work roll that can be rolled, it is described above. There was a problem that the work roll diameter was too large, the load was high, and a necessary reduction amount could not be obtained, and there were problems such as poor gloss.

  On the other hand, the 6-stage mill having the support roll within the roll width of the work roll has a small space for the support roll, and it is difficult to ensure sufficient strength and rigidity. Since there is a support bearing that supports the support roll, depending on the material, there is a problem that the mark of the support bearing is transferred and generated on the plate through the support roll and the work roll.

  The present invention has been proposed in view of such circumstances, and its purpose is to make it possible to use a work roll having a smaller diameter for hard material rolling, and to obtain a strip having high productivity and high product quality. It is providing a rolling mill and a tandem rolling mill provided with the rolling mill.

The rolling mill according to the present invention for solving the above problems is as follows.
A pair of upper and lower work rolls for rolling the metal strip, a pair of upper and lower intermediate rolls for supporting the work roll, and a pair of upper and lower reinforcing rolls for supporting the pair of upper and lower intermediate rolls. In a six-stage rolling mill that does not have a support roll within the rollable plate width,
Each provided at least two bearings on the operating side and the drive side of the pair of upper and lower work rolls, the restraining means for restraining the bearings entry side or the delivery side of the bearing is provided, horizontal of the bearing each by said restraining means Directional displacement is constrained and the work roll is fixedly supported .

Further, it is composed of a pair of upper and lower work rolls for rolling the metal strip and a pair of upper and lower reinforcing rolls for supporting the work roll, and is a four-stage type having no support roll within the rollable plate width of the work roll. In the rolling mill,
Each provided at least two bearings on the operating side and the drive side of the pair of upper and lower work rolls, the restraining means for restraining the bearings entry side or the delivery side of the bearing is provided, horizontal of the bearing each by said restraining means Directional displacement is constrained and the work roll is fixedly supported .

The minimum roll diameter of the work roll is between a minimum diameter upper limit Dmax1 and a minimum diameter lower limit Dmin1, which are expressed by the following formula.
Minimum diameter upper limit Dmax1 = D4max × B / 5 ^(1/4)
Here, D4max; upper limit of minimum diameter of work roll with conventional plate width of 1,300mm: φ380
B; Plate width (mm) / 1,300mm
Minimum diameter lower limit Dmin1 = D4min × B / 5 ^(1/4)
Here, D4min; Minimum working roll minimum diameter of conventional plate width 1,300mm: φ180

In addition, the work roll is made of a material having a high longitudinal elastic modulus with a ratio of K = 1.2 to 3.0 with a conventional material having a longitudinal elastic modulus of 21,000 kg / mm ² , and the minimum roll diameter of the work roll is , Between the minimum diameter upper limit Dmax2 and the minimum diameter lower limit Dmin2, which are represented by the following equations.
Minimum diameter upper limit Dmax2 = D4max × B / (5 × K) ^(1/4)
Here, D4max; upper limit of minimum diameter of work roll with conventional plate width of 1,300mm: φ380
B; Plate width (mm) / 1,300mm
K: Ratio of high longitudinal elastic material to conventional material
(Longitudinal modulus of high longitudinal elastic material / longitudinal modulus of conventional material (21,000kg / mm ² ))
Minimum diameter lower limit Dmin2 = D4min x B / (5 x K) ^(1/4)
Here, D4min; Minimum working roll minimum diameter of conventional plate width 1,300mm: φ180
In the case where the work roll is a composite roll, it is preferable to use an equivalent longitudinal elastic modulus ratio as the longitudinal elastic modulus.

The tandem rolling mill according to the present invention for solving the above problems is
In the tandem rolling mill in which a plurality of rolling mill stands are arranged, at least one of the rolling mills is provided.

According to the configuration of the present invention, at least two bearings are provided on the operation side and the drive side of the pair of upper and lower work rolls so that the support of both ends of the work roll is equivalent to the fixed support from the simple support. By providing a restraining means for restraining the bearing on the entry side or the exit side, restraining a horizontal displacement of each of the bearings by the restraining means, and fixing and supporting the work roll, a tangential force for driving an intermediate roll or a work roll It is possible to suppress the deflection of the work roll caused by the driving input / output side differential tension, and as a result, it is possible to reduce the diameter of the work roll, thereby reducing edge drop and improving surface gloss. In particular, it is suitable for cold rolling.

  Moreover, the work roll diameter can be further reduced by using a work roll made of a cemented carbide or ceramic material having a high longitudinal elasticity.

It is a front sectional view of a 6-stage mill showing Example 1 of the present invention. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is explanatory drawing of a taper wedge liner. It is explanatory drawing of a composite roll. It is explanatory drawing of the entrance / exit side differential tension | tensile_strength. It is explanatory drawing of the bending of a work roll. It is explanatory drawing of the bending of a work roll. It is a graph which shows the comparison of Example 1, 2 and the conventional work roll minimum diameter upper limit Dmax. It is a graph which similarly shows the comparison of work roll minimum diameter minimum Dmin. It is explanatory drawing of a drive tangential force. It is explanatory drawing of the work roll offset which shows the application example of Example 1,2. It is explanatory drawing of the load similarly applied to a work roll. It is explanatory drawing of the intermediate | middle roll offset which shows another application example of Example 1,2. It is explanatory drawing of the load similarly applied to a work roll. It is explanatory drawing of the work roll shift of the 6-stage mill which shows another application example of Example 1,2. It is a front sectional view of a four-stage mill showing Example 3 of the present invention. It is the XV-XV sectional view taken on the line of FIG. It is explanatory drawing of the work roll shift of the 4-step mill which shows the application example of Example 3. FIG. It is application explanatory drawing to the tandem rolling mill of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a rolling mill according to the present invention and a tandem rolling mill equipped with the rolling mill will be described in detail using embodiments with reference to the drawings.

  1 is a front sectional view of a six-stage mill showing Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. It is explanatory drawing of a liner.

  As shown in the figure, a strip 1 as a material to be rolled is rolled by a pair of upper and lower work rolls 2. The pair of upper and lower work rolls 2 are each contacted and supported by a pair of upper and lower intermediate rolls 3, and the pair of upper and lower intermediate rolls 3 are each supported by a pair of upper and lower reinforcing rolls 4.

  The upper reinforcing roll 4 is supported by bearing housings 17a and 17c via bearings (not shown). These bearing housings 17a and 17c are pass line adjusting devices 5a such as worm jacks or tapered wedges and stepped rocker plates. , 5b through the housings 7a, 7b. Here, a load cell may be built in the pass line adjusting devices 5a and 5b to measure the rolling load.

  The lower reinforcing roll 4 is supported by bearing housings 17b and 17d through bearings (not shown), and the bearing housings 17b and 17d are supported by housings 7a and 7b through hydraulic cylinders 6a and 6b. .

  Here, bearing boxes 13a to 13d and 13e to 13h are attached to the roll neck portions of the pair of upper and lower work rolls 2 via bearings (not shown). These bearing boxes 13a to 13h are pressed against the projecting project blocks 19a and 19c by the backlash removing cylinders 18a to 18d and 18e to 18h provided in the projecting blocks 19b and 19d on the entry side, and the bearings Each horizontal displacement is constrained.

  The project blocks 19a, 19b, 19c and 19d are provided with bending cylinders 14a to 14d and 14e to 14h for applying roll bending. As a result, roll bending of the work roll 2 is applied, and the plate shape can be corrected. In this embodiment, the backlash removing cylinders 18a to 18d and 18e to 18h are provided on the entry side, but may be provided on the exit side or both sides.

  In this embodiment, the backlash removing cylinders 18a to 18d and 18e to 18h are shown. However, a worm jack or a tapered wedge liner that operates a tapered wedge with a hydraulic cylinder or the like may be used. The operation of this tapered wedge liner will be described with reference to FIG. When the taper wedge 21 is pushed to the left in the horizontal direction in the figure by the hydraulic cylinder 20, the taper liner 22 is restrained in the horizontal direction by the stopper 23, so that the wedge part slides and consequently moves in the vertical direction. Thus, the bearing boxes 13a to 13d and 13e to 13h can be restrained.

  Here, the rolling load is applied by the hydraulic cylinders 6a and 6b, and the rolling torque is transmitted to the work roll 2 from a spindle (not shown). The pair of upper and lower intermediate rolls 3 have roll shoulders 3a each having a roll diameter decreasing at a roll barrel end position symmetrical with respect to the upper and lower points with respect to the center of the width of the band plate 1. In the case of intermediate roll driving, the rolling torque is transmitted to the work roll 2 via the intermediate roll 3 from a spindle (not shown).

  The pair of upper and lower intermediate rolls 3 are supported by bearing boxes 15a to 15d via bearings (not shown). The pair of upper and lower intermediate rolls 3 can be moved in the axial direction by a shift device (not shown) via drive-side bearing boxes 15c and 15d. Further, these bearing boxes 15a to 15d are provided with bending cylinders 16a to 16d for applying roll bending. This gives roll bending to the intermediate roll 3.

  Thus, in this embodiment, two bearing boxes 13a to 13d and 13e to 13h are respectively attached to the roll neck portions of the pair of upper and lower work rolls 2, and these bearing boxes 13a to 13h. Is pressed against the project blocks 19a and 19c on the exit side by the input side play cylinders 18a to 18h, the horizontal displacement of each of the bearings is restricted, and the tangential force of the intermediate roll drive or the input / output difference of the work roll drive Deflection of the work roll 2 caused by tension can be suppressed. As a result, the work roll diameter can be reduced.

  As a result, it is possible to use a work roll 2 having a smaller diameter for hard material rolling, to reduce edge drop and improve surface gloss, to obtain a high product quality strip 1 and to achieve high productivity. can get.

  Next, a second embodiment of the present invention will be described.

The feature of this embodiment is that a material having a high longitudinal elastic modulus is used for the pair of upper and lower work rolls 2 in the first embodiment. Examples of the material having a high longitudinal elastic modulus include cemented carbide such as tungsten carbide (longitudinal elastic modulus: 53,000 kg / mm ² ) and ceramics (longitudinal elastic modulus: 31,000 kg / mm ² ). In addition, special forged steel (longitudinal elastic modulus: 21,000 kg / mm ² ) or the like has been used as a conventional material.

  The ratio of the high longitudinal elastic material to the conventional material (longitudinal elastic modulus ratio K) is preferably set to K = 1.2 to 3.0.

Further, as shown in FIG. 5, a roll composite material using a high longitudinal elastic material for the roll surface layer material 2A and a conventional material for the roll inner layer material 2B may be used as a pair of upper and lower work rolls 2. . In this case, the longitudinal elastic modulus is obtained by multiplying the equivalent longitudinal elastic modulus ratio shown below by the longitudinal elastic modulus of the roll inner layer material (for example, conventional material) .

That is, assuming that the outer diameter of the roll surface layer material 2A is d2, the longitudinal elastic modulus is E2, the outer diameter of the roll inner layer material 2B is d1, and the longitudinal elastic modulus is E1, the equivalent longitudinal elastic modulus ratio Ee is the following (1) It is expressed by a formula.

Ee = (d1 ⁴ + (d2 ⁴ −d1 ⁴ ) × E2 / E1) / d2 ⁴ (1)

  Thus, in this embodiment, two bearing boxes 13a to 13h are respectively attached to the roll neck portions of the pair of upper and lower work rolls 2, and these are removed by the backlash cylinders 18a to 18h. Since the work roll 2 made of a cemented carbide or ceramic material having a high longitudinal elastic modulus is used to restrain the horizontal displacement of each of the two bearing housings 13a to 13h, the work roll diameter can be further reduced, and the hard material The strip 1 having high productivity and high product quality can be obtained in rolling.

  Here, first, with respect to Example 1, the deflection of the work roll due to the differential tension at the entrance and exit of the rolling mill will be described with reference to FIGS. 6, 7A, and 7B.

First, as shown in FIG. 6, assuming that the entry side tension of the rolling mill is Tb and the exit side tension is Tf, a differential tension that is a difference between these is applied to the work roll 2. Since the work roll has one bearing on each of the operation side and the drive side, the support condition for simple support shown in FIG. 7A is satisfied. The horizontal deflection δs of the work roll in this case is expressed by the following equation (2). Here, the differential tension per unit length is F, the support interval is L, the diameter of the conventional work roll 2 is Dc, the cross-sectional secondary moment of the conventional work roll diameter is Ic, the material of the conventional work roll (special forged steel ) Is the elastic modulus of elasticity (21,000kg / mm ² ).

^{δs = 5 × F × L 4} / (384 × Ec × Ic) (2) where ^{formula, Ic = π × Dc 4/} 64
F = (Tf−Tb) / L / 2

Similarly, in the case of the first embodiment, two bearing boxes 13a to 13h are respectively attached to the roll neck portions of the pair of upper and lower work rolls, and these two bearing boxes are connected by the backlash cylinders 18a to 18h. Since each horizontal displacement of 13a-13h is restrained, it becomes the support conditions of the fixed support shown to FIG. 7B. In this case, the horizontal deflection δf of the work roll is expressed by the following equation (3). Here, the diameter of the work roll of Example 1 is Df, and the cross-sectional secondary moment of the diameter of the work roll of Example 1 is If.

^{δf = F × L 4 / (} 384 × Ec × If) (3) Equation ^{where, If = π × Df 4/} 64
Here, assuming that δf = δs, Df is expressed by the following equation (4).

Df = Dc / 5 ^(1/4) (4) Formula

  Here, Patent Document 2 describes a method in which only one bearing is pressed with a pressing cylinder on each of the operation side and the driving side. However, in this method, only one bearing is pressed. The conditions for fixing and supporting the roll end shown in 7B cannot be made, and the conditions for supporting the roll end as shown in FIG.

On the other hand, the minimum roll diameter of the work roll is between the minimum diameter upper limit Dmax1 and the minimum diameter lower limit Dmin1, and these are expressed by the following expression from the above expression (4).

Minimum diameter upper limit Dmax1 = D4max x B / 5 ^(1/4) (5) where D4max; Conventional work roll minimum diameter upper limit of 1,300mm: φ380
B; Plate width (mm) / 1,300mm
The minimum diameter upper limit Dmax1 for each plate width of Example 1 is shown in FIG.

Minimum diameter lower limit Dmin1 = D4min x B / 5 ^(1/4) (6) where D4min; Minimum roll diameter lower limit for conventional rolls of 1,300 mm: φ180
The minimum diameter lower limit Dmin1 for each plate width of Example 1 is shown in FIG.

In the case of Example 2, two bearing boxes 13a to 13h are respectively attached to the roll neck portion of the upper and lower work rolls, and these are mounted on the two bearing boxes 13a to 13h by the backlash cylinders 18a to 18h. Since each horizontal displacement is restrained, it becomes the support conditions of the fixed support shown in FIG. 7B. In addition, the pair of upper and lower work rolls 2 uses a material having a high longitudinal elastic modulus. Examples of the material having a high longitudinal elastic modulus include cemented carbide and ceramic. The horizontal deflection δfr of the work roll 2 in this case is expressed by the following equation. The diameter of the work roll 2 of Example 2 is Dfr, the sectional moment of the work roll diameter of Example 2 is Ifr, and the longitudinal elastic modulus of the work roll material of Example 2 is Er.

^{δfr = F × L 4 / (} 384 × Er × Ifr) (7) where ^{equation, Ifr = π × Dfr 4/} 64
Here, assuming that δfr = δs, Dfr is expressed by the following equation (8).

Dfr = Dc / (5 × K) ^(1/4) (8) Formula

On the other hand, the minimum roll diameter of the work roll is between the minimum diameter upper limit Dmax2 and the minimum diameter lower limit Dmin2, and these are expressed by the following equation (9).

Minimum diameter upper limit Dmax2 = D4max x B / (5 x K) ^(1/4) (9) where D4max; Maximum work roll minimum diameter upper limit of conventional plate width 1,300mm: φ380
B; Plate width (mm) / 1,300mm
K: Ratio of high longitudinal elastic material to conventional material
(Longitudinal modulus of high longitudinal elastic material / longitudinal modulus of conventional material (21,000kg / mm ² ))
The minimum diameter upper limit Dmax2 for each plate width of Example 2 is shown in FIG. However, the work roll material was K = 2.5 in the case of cemented carbide.

Minimum diameter lower limit Dmin2 = D4min × B / (5 × K) ^(1/4) (10) where D4min; Minimum work roll minimum diameter of conventional plate width 1300mm: φ180
The minimum diameter lower limit Dmin2 for each plate width of Example 2 is shown in FIG. However, the work roll material was K = 2.5 in the case of cemented carbide.

In the above, the example of the work roll drive has been described. However, in the case of the intermediate roll drive shown in FIG. 10, the drive tangential force Fd is taken into account, and the F is expressed by the following equation.

F = (Tf−Tb) / L / 2−Fd / L (11) However, the result is the same as that in the above-described work roll driving example.

  Further, as shown in FIGS. 11A and 11B, the work roll 2 may be variably offset to the entry side in the horizontal rolling direction according to the magnitude of the entry / exit side differential tension (Tf−Tb) / 2 ( (See offset amount α in FIG. 11A). Thereby, the input / output side differential tension (Tf−Tb) / 2 is reduced by the offset horizontal component Fa of the rolling load Q, and the total horizontal force applied to the work roll 2 is reduced. In FIG. 11B, Fb represents the offset vertical component.

As a result, there is an advantage that the deflection of the work roll 2 can be further reduced.
The total horizontal force applied to the work roll 2; Fw is expressed by the following equation (12).

Fw = (Tf−Tb) / 2−Q × α / ((Dw + DI) / 2) (12) Here, the work roll diameter is Dw, and the intermediate roll diameter is DI.

  Moreover, as shown in FIGS. 12A and 12B, the intermediate roll 3 may be variably offset to the outgoing side in the horizontal rolling direction according to the magnitude of the incoming / outgoing differential tension (Tf−Tb) / 2 ( (See offset amount β in FIG. 12A). As a result, the input / output differential tension (Tf−Tb) / 2 is reduced by the offset horizontal component Fa of the rolling load Q, and the total horizontal force applied to the work roll 2 of the high longitudinal elastic material is reduced. . In FIG. 12B, Fb represents the offset vertical component.

As a result, there is an advantage that the deflection of the work roll 2 can be further reduced.
The total horizontal force applied to the work roll 2; Fw is expressed by the following equation (13).

Fw = (Tf−Tb) / 2−Q × β / ((Dw + DI) / 2) (13) Here, the work roll diameter is Dw, and the intermediate roll diameter is DI.

  In the first and second embodiments, the pair of upper and lower work rolls 2 does not show a structure that shifts in the axial direction, but the work roll 2 may have a structure that can be shifted in the axial direction as described below. In addition, the shift structure of a work roll has a structure shown by patent document 3, for example.

  As shown in FIG. 13, the pair of upper and lower work rolls 2 each have a tapered roll shoulder 2 a at the position of the roll barrel end in the vertical point symmetric direction with respect to the plate width center of the strip 1. In addition, two bearings (not shown) are attached to the operation side and the drive side of the roll neck portion of the pair of upper and lower work rolls 2. The pair of upper and lower work rolls 2 can be moved in the axial direction by a shift cylinder (not shown) via a drive-side bearing (not shown).

  Next, an edge drop reduction method by shifting the work roll 2 having a tapered roll shoulder 2a will be described below. First, the work roll 2 is provided with a tapered roll shoulder 2a in the direction of vertical symmetry. The distances from the roll shoulder position to the plate edge are represented by δw and δd. In addition, a plate thickness meter (not shown) is provided for measuring the plate thickness at one point or a plurality of points in the vicinity of the plate ends on the operation side and the drive side on the rolling mill exit side.

  If the plate thickness at one point or a plurality of points near the plate end measured on the operation side is smaller than the predetermined plate thickness, the upper work roll 2 is shifted in the roll axis narrow direction. That is, the upper work roll 2 is shifted in the direction of increasing δw. Conversely, if the plate thickness near the plate end portion measured is thicker than the predetermined plate thickness, the upper work roll 2 is shifted in the roll axis wide direction. That is, the upper work roll 2 is shifted in the direction of decreasing δw.

  Further, when the plate thickness at one point or a plurality of points in the vicinity of the plate end portion measured on the driving side is different from the predetermined plate thickness, the lower work roll 2 is similarly shifted to the predetermined plate thickness. Since the work roll diameter can be reduced by the application of the work roll 2 that is originally a high longitudinal elastic material, the rolling load can be reduced by that amount, resulting in a sharp edge of the plate edge called an edge drop that causes a decrease in yield. Thickness reduction can be reduced.

  The combined use of this small-diameter work roll and work roll shift makes it possible to minimize the tapered roll shoulder 2a and the shift positions δw, d, and to roll brittle materials such as electrical steel sheets that are susceptible to cracking. Is particularly suitable. In addition, although this figure has described the mill of FIG. 1 as a representative, the work roll variable offset mill of FIG. 11 and the intermediate roll variable offset mill of FIG. 12 may be used.

  In the first and second embodiments, the pair of upper and lower intermediate rolls 3 have roll shoulders 3a each having a roll diameter that is symmetric with respect to the center of the width of the strip 1 at the roll barrel end position. However, the pair of upper and lower intermediate rolls 3 are provided with S-curve roll crowns that are symmetrical with respect to the plate width center of the strip 1 as shown in Non-Patent Document 1, and are axially oriented. It is good also as a structure shifted to. In this case, the shape control ability is inferior to that of the 6-stage mill having the roll shoulder 3a, but the shape control ability is superior to that of the 4-stage mill. Further, the work roll shift shown in FIG. 13 described above may be applied to this mill.

  14 is a front sectional view of a four-stage mill showing Embodiment 3 of the present invention, FIG. 15 is a sectional view taken along line XV-XV of FIG. 14, and FIG. 16 is a work roll shift of a four-stage mill showing an application example of Embodiment 3. It is explanatory drawing of.

  As shown in FIGS. 14 and 15, the rolling mill of the present embodiment is a four-high rolling mill, and a pair of upper and lower intermediate rolls 3 and bearing boxes 15 a to 15- 15d, and a set of bending cylinders 16a to 16d are removed. In this case, the plate shape control ability is greatly reduced, but the structure becomes simpler.

  In the present embodiment, the pair of upper and lower work rolls 2 do not show a structure that shifts in the axial direction. However, as shown in FIG. It is good also as a structure which has the taper-shaped roll shoulder 2a in the point position of a roll trunk | drum of a point symmetry direction, respectively, and can shift to an axial direction. According to this, edge drop can be reduced with a simpler structure.

  In the application example, the pair of upper and lower work rolls 2 each have a tapered roll shoulder 2a at the position of the roll barrel end in the vertical point symmetric direction with respect to the center of the width of the strip 1, and the axial direction An example of a shiftable structure is shown, but the upper and lower pair of work rolls 2 have S-curve roll crowns symmetrical with respect to the upper and lower points with respect to the center of the width of the strip 1 as shown in Non-Patent Document 1. A structure may be provided and shifted in the axial direction. In this case, the shape control capability is superior to the four-stage mill shown in FIG.

  When the small diameter work roll rolling mill of the present invention is applied to a tandem rolling mill, as shown in FIG. When applied to a single stand, strong reduction is possible by a small diameter work roll made of high longitudinal elastic material. The final stand, NO. When applied to 4 stands, a thin plate can be rolled by a small diameter work roll of a high longitudinal elastic material. Of course, you may apply the small diameter work roll rolling mill of this invention about all the stands. Thereby, a thinner and harder material can be rolled. In this figure, as a small diameter work roll mill of the present invention, a 6-stage mill is shown as a representative, but a 4-stage mill can be similarly applied.

DESCRIPTION OF SYMBOLS 1 Strip plate 2 Work roll 3 Intermediate roll 4 Reinforcement roll 5a, 5b Pass line adjusting device 6a, 6b Hydraulic cylinder 7a, 7b Housing 13a-13d and 13e-13h Work roll bearing box 14a-14d Work roll bending cylinder 15a-15d Intermediate Roll bearing box 16a to 16d Intermediate roll bending cylinder 17a to 17d Reinforced roll bearing box 18a to 18d and 18e to 18h Roughing cylinder 19a to 19d Project block

Claims (5)

A pair of upper and lower work rolls for rolling the metal strip, a pair of upper and lower intermediate rolls for supporting the work roll, and a pair of upper and lower reinforcing rolls for supporting the pair of upper and lower intermediate rolls. In a six-stage rolling mill that does not have a support roll within the rollable plate width,
Each provided at least two bearings on the operating side and the drive side of the pair of upper and lower work rolls, the restraining means for restraining the bearings entry side or the delivery side of the bearing is provided, horizontal of the bearing each by said restraining means A rolling mill characterized by restraining directional displacement and fixedly supporting the work roll . A four-stage rolling mill comprising a pair of upper and lower work rolls for rolling a metal strip and a pair of upper and lower reinforcing rolls for supporting the work roll, and having no support roll within the roll width of the work roll. In
Each provided at least two bearings on the operating side and the drive side of the pair of upper and lower work rolls, the restraining means for restraining the bearings entry side or the delivery side of the bearing is provided, horizontal of the bearing each by said restraining means A rolling mill characterized by restraining directional displacement and fixedly supporting the work roll . The rolling mill according to claim 1 or 2, wherein a minimum roll diameter of the work roll is between a minimum diameter upper limit Dmax1 and a minimum diameter lower limit Dmin1, and these are expressed by the following formula.
Minimum diameter upper limit Dmax1 = D4max × B / 5 ^(1/4)
Here, D4max; upper limit of minimum diameter of work roll with conventional plate width of 1,300mm: φ380
B; Plate width (mm) / 1,300mm
Minimum diameter lower limit Dmin1 = D4min × B / 5 ^(1/4)
Here, D4min; Minimum working roll minimum diameter of conventional plate width 1,300mm: φ180 The work roll is made of a material having a high longitudinal elastic modulus with a ratio of K = 1.2 to 3.0 to the conventional material having a longitudinal elastic modulus of 21,000 kg / mm ² , and the minimum roll diameter of the work roll is the maximum. 3. The rolling mill according to claim 1, wherein the rolling mill is between a small diameter upper limit Dmax2 and a minimum diameter lower limit Dmin2, which are expressed by the following formula.
Minimum diameter upper limit Dmax2 = D4max × B / (5 × K) ^(1/4)
Here, D4max; upper limit of minimum diameter of work roll with conventional plate width of 1,300mm: φ380
B; Plate width (mm) / 1,300mm
K: Ratio of high longitudinal elastic material to conventional material
(Longitudinal modulus of high longitudinal elastic material / longitudinal modulus of conventional material (21,000kg / mm ² ))
Minimum diameter lower limit Dmin2 = D4min x B / (5 x K) ^(1/4)
Here, D4min; Minimum working roll minimum diameter of conventional plate width 1,300mm: φ180 A tandem rolling mill in which a plurality of rolling mill stands are arranged, wherein at least one stand is provided as the rolling mill according to any one of claims 1 to 4 .

Images