JPH11314107A - Rolling mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high efficiency rolling by providing mechanisms for reducing the vibration of a rolling mill by increasing the dynamic rigidity in the horizontal direction of the rolling mill and for reducing friction in the vertical direction of a head part for pressing against. SOLUTION: This rolling mill is provided with a pair of upper and lower work rolls 4 in a housing 1 of the rolling mill, roll chocks 6 for supporting the work rolls 4 and screw driving mechanisms or hydraulic cylinders 8, 9 for pressing the roll chocks 6 against in the horizontal direction. In such a case, work roll crossheads 13 or housing liners for always pressing the roll chocks toward the perpendicular direction of the roll chocks in the horizontal direction are provided at the tips of the screw driving mechanisms or the hydraulic cylinders 8, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a rolling mill.
Particularly, in a rolling mill for rolling a strip, a steel bar, or the like, a mechanism for preventing vibration in a traveling direction is added.

[0002]

2. Description of the Related Art FIG. 11 shows a rolling mill according to the prior art.
FIG. 11A shows a conventional general four-high rolling mill.
(B) is a side view showing an example of a general four-stage cross rolling mill. In the four-stage cross rolling mill shown in FIG. 11 (b), a backup roll 3 and a work roll 4 are mounted on a roll chock 5 and a roll chock 6, respectively, and a roll is provided between the inside of the housing 1 and the roll chocks 5 and 6. A pair of crossheads 7b for crossing 3 and 4 are arranged, and these components are provided above and below the bus line of the housing 1.

In the four-high rolling mill shown in FIG. 11A, a housing liner 7a is provided instead of the crosshead 7b. The lowering means 11 has its lower end attached to the roll chock 5 and expands and contracts vertically by a lowering device (not shown). The roll gap between the upper and lower work rolls 4 and 4 is adjusted to an appropriate value via the roll chock 5 and the backup roll 3. Set. Then, the conveyed strip 2 is engaged between the work roll gaps 4, 4, and receives a rolling load from the pressing means 11 while rotating the upper and lower work rolls 4 and the backup roll 3, so that the strip 2 is moved to a predetermined position. Rolled into thin steel plates.

At the time of rolling, a large rolling load F is applied to the housing 1 as shown in FIG.
The reaction force F of the rolling load acts on the upper portion of the housing 1, and the side portion of the housing 1 narrows inward, and a deformation of an amount δ occurs. Also,
The crosshead 7b is displaced by cross screws or hydraulic cylinders 8 and 9, which are in mechanical contact with it, to position the cross points of the rolls 3 and 4.

At this time, in the rolling state in which the rolling load F is applied, the hysteresis of the vertical control of the rolls 3 and 4 of the housing is minimized, and the roll thickness is controlled with high accuracy. In order to facilitate the roll exchange when the roller 3 is worn, FIG.
As shown in (1), the gap G is provided between the roll chocks 5 and 6 and the crosshead 7b by the pullback cylinder 10. In a device which is not a cross rolling mill, even if the side portion of the housing 1 is narrowed in the rolling state where the rolling load F is applied and the amount of deformation δ is caused, the housing liner 7a and the roll chocks 5 and 6 are used for the same reason as the cross rolling mill.
Is provided.

In such a conventional rolling mill, even if the housing 1 is narrowed by the rolling load at the time of rolling and the housing 1 is deformed by the amount δ, the gap G is, for example, about 0.2 mm to 1 mm. Due to the presence of the gap, the horizontal dynamic rigidity of the rolling mill was sometimes reduced. For this reason, when rolling is performed at a high-pressure reduction and a high-pressure reduction in a state where the horizontal dynamic rigidity is low, a large vibration which is considered to be caused by the friction between the rolled material and the rolling roll occurs in the rolling roll, the housing, etc., This hindered high-efficiency rolling.

[0007]

According to the present invention, a crosshead or a housing liner is positively pressed against a roll chock to reduce the gap to zero and to apply a cross screw or hydraulic cylinder with an offset force exceeding the gap to zero. And the housing is slightly deformed to increase the horizontal dynamic stiffness of the rolling mill to reduce the vibration of the rolling mill and to provide a mechanism to reduce the vertical friction of the pressing head. The purpose is to enable efficient rolling.

[0008]

According to a first aspect of the present invention, there is provided a rolling mill, comprising: a pair of upper and lower work rolls in a housing of the rolling mill; A rolling mill provided with a screw drive mechanism or a hydraulic cylinder to press the roll chock in a horizontal direction, wherein the roll chock is constantly pressed in a horizontal direction toward the tip of the screw drive mechanism or the hydraulic cylinder in a direction perpendicular to the roll chock. A work roll crosshead or a housing liner is provided.

According to a second aspect of the present invention, there is provided a rolling mill according to the first aspect, wherein a rotatable rolling element or a grease pad is mounted on a roll chock side of the work roll crosshead or the housing liner. It is characterized by.

According to a third aspect of the present invention, there is provided a rolling mill comprising: a pair of upper and lower work rolls, a roll chock for supporting the work roll, and a horizontal pressing of the roll chock in a housing of the rolling mill. A rolling mill provided with a hydraulic cylinder for performing a work roll crosshead or a housing liner that always presses a roll chock horizontally in a direction perpendicular to the roll chock at the tip of the hydraulic cylinder. A properly set auxiliary piston is installed, and the damping of roll vibration is increased by controlling the oil pressure or oil viscosity.

[0011]

Embodiments of the present invention will be described below in detail with reference to embodiments shown in the drawings. [Embodiment 1] A rolling mill according to a first embodiment of the present invention is shown in FIG.
Shown in FIG. 1 (a) is applied to a four-high rolling mill, and FIG. 1 (b) is applied to a four-high rolling mill that is not a cross type.

In the four-stage cross rolling mill of the present embodiment shown in FIG. 1 (a), rolling elements 15, 15 'or rotatable to the roll chock side of crossheads 12, 13 provided on the housing side of the cross rolling mill. The grease pad 19 is provided to reduce the vertical resistance of the roll chock portion. The crossheads 12, 13 are shown in FIG.
As shown in (a), as an example, it is configured separately.
The crossheads 12 and 13 may be an integral member.

FIG. 1B shows another embodiment of the present invention, in which a housing liner 7 'having an equivalent function is provided in place of the crossheads 12, 13. As shown in FIG.
Hereinafter, the cross head 13 of the work roll 4 will be described in detail, but the backup roll 3 has the same configuration. The same members as those of the prior art described with reference to FIGS. 11 to 13 are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 1A, the housing 1 is
Each is provided with a screw mechanism or a hydraulic cylinder mechanism 8, 9 so that the crosshead 13 can be pressed against the roll chock 6 and an offset force can be applied. When the crossheads 12 and 13 are integral members, the screw drive mechanisms or the hydraulic cylinder mechanisms 8 and 9 may be provided one each for the upper and lower parts.

FIG. 2 shows the displacement δ of the housing due to the rolling load F during rolling, the crosshead 13 or the housing liner 7 ′ pressed against the roll chock 5 by a screw drive mechanism or hydraulic cylinder mechanisms 8, 9, and an offset force F ′. Shows the relationship between the total housing displacement when the displacement of the housing is reduced by δ ′ due to the application of.

3, when the pressing mechanism 9 fixed to the housing 1 is a screw driving mechanism, the screw 18 is inserted into the crosshead 13 through a hole in the housing. Are connected via a connection portion 16. The connecting portion 16 transmits only the movement of the screw 18 in the axial pressing direction, and the screw 1
It has a mechanism that does not transmit the rotation of 8 to the rod 17.

If the pressing mechanism 9 fixedly installed on the housing 1 is a hydraulic cylinder mechanism, the crosshead 13
The connection to is only required by the rod 17. The compression and bending stiffness of the rod is set to be greater than the horizontal stiffness of the housing. The same structure is applied to the cross head 12 of the backup roll 3.

Further, when the surface of the crosshead 13 is to be pressed against the roll-chock surface, it is necessary to keep the surface parallel to the roll-chock surface. The rod 17 and the pin 14 are connected so that they can be rotated together.
As shown in FIG. 4, a rotatable rolling element 15, 15 'or a grease pad 19 is mounted on the crosshead 13.

The rolling elements 15 and 15 'are
The outer peripheral surface is attached so as to slightly protrude therefrom. As shown in FIG. 4A, the shape may be a cylindrical rolling element 15 rotatable about a horizontal direction as a rotation axis.
As shown in (b), a spherical rolling element 15 'may be used. As shown in FIG. 4C, the grease pad 19 is press-fitted from a side opposite to a surface where the grease contacts the roll chock.
The grease spreads thinly from the cone-shaped portion 19 to the contact surface between the crosshead 13 or the housing liner 7 'and the chock, and the resistance can be reduced without reducing the rigidity.

The rolling elements 15 or 15 'mounted on the crosshead 13 are appropriately selected in shape, number, mounting location, etc. according to the structure of the rolling mill, the offset force applied to this portion, and the required static rigidity. is there. The structure of the crosshead 13 of the work roll 4 shown in FIGS. 3 and 4 is similarly applied to the crosshead 12 of the backup roll 3. FIG. 5 is a front view of the main part of the work roll of the rolling mill as viewed from the front (in the direction indicated by arrows V-V in FIG. 3).
Are shown before and after the gap G is eliminated by pressing the gap G with an offset force.

As shown in FIG. 5A, at the time of non-rolling, a gap G between the roll chock 6 and the crosshead 13 is secured between the roll chock 6 and the crosshead 13 so that the roll can be easily replaced. As shown in FIG. 5B, in the rolling state or the preparation state thereof, the work roll crosshead 13 or the housing liner is pressed against the roll chock 6 with an offset force F ′, the gap G is zero, and the housing 1 Is δ 'deformed. The same structure is applied to the cross head 12 of the backup roll 3.

As described above, by the screw drive mechanism or the hydraulic cylinder mechanism provided in the housing 1, the roll chocks 5, 6 are pressed by the offset force F 'to make the gap G zero, and the housing is deformed by the offset force F'. The horizontal dynamic rigidity of the roll is increased, and at the same time, the rolling elements 15 and 15 ′ are attached to the crosshead 13 of the work roll 4.
Alternatively, the grease pad 19 is provided to reduce the frictional resistance of the roll chock 6 in the vertical direction. With these configurations, vibrations can be prevented in comparison with the prior art, and high-accuracy plate thickness control can be ensured.

In the above embodiment, a four-high rolling mill has been described. However, the present invention is not limited to the four-high rolling mill, but can be implemented in other rolling mills. Further, the mechanism for pressing the work roll 4 by the crosshead 13 can be effective even if it is pressed in one direction to the crosshead 13 on the exit side of the band plate 2.

The embodiment shown in FIGS.
The present invention can be applied to a non-cross type rolling mill shown in FIG. 4B, and a housing liner 7 'having the same structure as the cross head shown in FIG.

The pressing mechanisms 8 and 9 are the same as those of the cross type.
Individuals are acceptable. If it is not a cloth, the housing liner 7 ′ may be fixed to the bar 17 and have no rotation pin 14. The same structure is applied when the work roll is a cross type and the backup roll is not a cross type.

According to the rolling mill according to the present embodiment configured as described above, the roll gap between the upper and lower work rolls 4, 4 is established via the roll chock 5, the backup roll 3, the roll chock 6, and the work roll 4. The belt material 2 which is set to a predetermined value and is conveyed is bitten between the upper and lower work rolls 4, 4, and the lower and upper work rolls 4, 4 and the backup rolls 3, 3 are rotated while the lowering from the lowering means 11 is performed. Under the load, the strip 2 is rolled into a thin steel plate having a predetermined thickness.

At the time of rolling, the gap G of the roll chock 6 is changed from the state shown in FIG. 5A to the gap G shown in FIG. 5B by pressing the roll chock by the screw drive mechanism or the hydraulic cylinders 8 and 9 provided in the housing. State and the gap G can be set to zero. Further, the housing is deformed by δ ′ in the horizontal direction by the offset force F ′, whereby the effect of the horizontal rigidity on both sides of the housing is exerted on the roll, so that the horizontal dynamic rigidity of the roll increases, and the horizontal Directional vibration is less likely to occur.

FIGS. 6 and 7 show the relationship between the horizontal displacement of the chocks and the horizontal reaction force from the housing to the chocks. The slope of the graph indicates the horizontal rigidity. FIG. 6A shows that the roll chock is offset from the offset force F ′.
And the case where the deformation amount δ ′ of the housing is positive. When the roll chock displacement exceeds δ ′, the rigidity from the housing post opposite to the displacement direction x does not act, and the inclination (rigidity) decreases. Effective horizontal stiffness, the horizontal amplitude of roll vibrations as x _0, 'determined by, (whether the x ₀ large, [delta] eta is larger the' vibrational amplitude ratio eta = x ₀ / [delta] if small) Effective The horizontal stiffness is reduced.

FIG. 6B shows the case where the roll chock is not pressed by the offset force F 'and the housing deformation δ is 0 or negative. In this case as well, the effective horizontal rigidity is determined by the vibration amplitude ratio η = x ₀ / δ ′. In this case, as η increases (when x ₀ is large or δ ′ is small), the effective horizontal stiffness is increased. Rigidity increases. FIG.
Shows the relationship between the gap amount G or the housing deformation amount δ ′ and the horizontal rigidity when the vibration amplitude is x _{0 to} 0.1 mm.

The high pressure force, but the vibration in the rolling roll and is rolling under high pressure ratio occurs, if the amount of the gap is greater than the vibration amplitude x ₀ (case of the left than in FIG. 7 A point), chocks is Since it comes into contact only with the housing on either the entry side or the exit side in the passing plate direction, the dynamic rigidity in the horizontal direction is small, and it is flat. Further, when the gap amount is smaller than the point A in FIG. 7, the roll chock comes into contact with the housing on the entrance side and the housing on the exit side at the time of vibration, so that the roll chock is restrained and the horizontal rigidity increases.

Further, as the housing deformation δ ′ increases due to the offset force, the roll chock is almost always
It comes into contact with the housing on both the entrance side and the exit side, and the rigidity in the horizontal direction increases. As described above, by pressing the roll chock against the housing, the horizontal deformation amount of the housing can be controlled by the gap G and the offset force F ′, so that the horizontal dynamic stiffness at the time of rolling is significantly larger than that of the conventional rolling mill. In addition, the occurrence of vibration during rolling can be reduced.

However, when the gap G is 0 or the housing deformation amount δ 'is positive, a frictional force is generated in the vertical direction because the roll chock is pressed down, and high-precision plate thickness control is not performed. Moving body 15, 1
5 ′ or grease pad 19, and
5 'is rotated at the time of contact, and the friction coefficient in the vertical direction is reduced by reducing the friction coefficient due to grease from the grease pad. As described above, by reducing the frictional resistance in the vertical direction, the vertical movement resistance of the roll chock portion is reduced, and the accuracy of the thickness control can be ensured.

When the mechanisms 8 and 9 for pressing the roll chocks are hydraulic cylinders, the rigidity of the oil becomes a problem. However, as shown in FIG. 8, the rigidity of the oil tends to increase with the frequency, and the hydraulic pressure is further increased. It is possible to increase the stiffness of the oil at the same frequency by the increase. Thus, rigidity can be ensured by controlling the hydraulic pressure in the hydraulic cylinders 8 and 9. As described above, according to the present embodiment, a predetermined gap amount G is secured during non-rolling, so that the roll can be easily replaced.

Embodiment 2 FIG. 9 shows a rolling mill according to a second embodiment of the present invention. FIG. 9 is a front view of the left half of an enlarged main part of the hydraulic cylinder for pressing roll chocks according to the embodiment. Although the first embodiment is an example using a commercially available normal hydraulic cylinder, the present embodiment aims at a greater vibration damping effect by adding a function of damping vibration to the hydraulic cylinder.

That is, in this embodiment, the crosshead 1 provided on the housing side of the rolling mill similar to the first embodiment is used.
The hydraulic cylinder 27 is used as the roll chock pressing mechanism 9 according to the third embodiment, and the damping of the roll vibration is increased in order to increase the horizontal dynamic rigidity of the roll chock 6 compared to the first embodiment. As shown in FIG. 9, a hydraulic cylinder 27 is
Oil inlets 25 and 26 are provided for controlling the oil amount, and the offset force to the crosshead 13 is controlled by the oil inlet 2.
The control is performed based on the balance between the hydraulic pressure and the oil amount from 5, 26.

Rollers 15, 15 'or grease pads 19 for reducing the vertical frictional resistance of the roll chock are mounted on the roll chock side of the cross head 13, as in the first embodiment. Inside the hydraulic cylinder 27, a seal member 23 is installed around the main piston 22,
Seal the oil pressure and oil amount. Further, in this embodiment, the length on either side main piston L, the auxiliary piston 2 having an outer diameter R ₁
4 are installed and immersed in oil.

The auxiliary piston 24 has a cylinder inner diameter R ₂
And the auxiliary piston outer diameter R ₁ , the total length of 2 L, and the damping determined by the viscosity constant of the oil. In this embodiment, these parameters (cylinder inner diameter R ₂ , auxiliary piston outer diameter R ₁ , length By setting the total of 2L and the viscosity constant of oil) to appropriate values, the increase in attenuation is used. The hydraulic cylinder 27 has been described by taking the rolling mill of Embodiment 1 as an example, but the present invention is not limited to this four-high rolling mill, but can be implemented in other rolling mills.

Further, the pressing mechanism by the work roll crosshead 13 using the hydraulic cylinder 27 exerts the effect even if it is pressed in one direction to the exit crosshead 13 of the strip 2 as shown in FIG. It is. The same structure is applied to the pressing mechanism of the housing liner 7 'of a non-cross type rolling mill as shown in FIG. 1 (b). Further, the same structure is applied to a case where the work roll is a cross type and the backup roll is not a cross type.

In the rolling mill constructed as in Embodiment 1, the hydraulic cylinder 2 constructed as in Embodiment 2 is used.
When using a 7 to pressing of the crosshead 13 or housing liner roll by setting a viscosity constant total 2L and oil of the cylinder inner diameter R ₂ and the auxiliary piston outer diameter R ₁ and the length of the auxiliary piston 24 to the appropriate value Vibration damping can be greater than in the prior art. In FIG.
Dynamic stiffness K (rigidity at the frequency of roll vibration) with respect to the oil pressure in the hydraulic cylinder, damping ratio ζ, dynamic stiffness 2ζ
The relationship of K is roughly shown.

The damping ratio becomes larger when the viscosity of the auxiliary piston and oil is set to an appropriate value than when no auxiliary piston is used. As the hydraulic pressure increases, the dynamic rigidity of the oil increases, but the relative displacement between the roll chocks and the housing decreases, so that the damping ratio slightly decreases. Therefore, dynamic stiffness is the product of the damping ratio and dynamic stiffness has a maximum value at a hydraulic P ₀ in. By setting this value P ₀ or a hydraulic pressure P close to this value P ₀ , the dynamic rigidity can be increased.

As described above, the horizontal dynamic rigidity of the roll can be increased by properly introducing the auxiliary piston into the hydraulic cylinder and adjusting the viscosity and oil pressure of the oil, and horizontal vibration of the rolling mill is less likely to occur. As in the first embodiment, in this embodiment, the rolling elements 15, 15 'or the grease pad 19 are mounted, and the rolling elements 15, 15' rotate upon contact.
Further, the friction resistance in the vertical direction is reduced by reducing the friction coefficient due to grease from the grease pad. As described above, by reducing the frictional resistance in the vertical direction, the vertical movement resistance of the roll chock portion is reduced, and the accuracy of the thickness control can be ensured.

[0042]

As described above in detail, the rolling mill according to the first aspect of the present invention comprises a pair of upper and lower work rolls in a housing of the rolling mill, a roll chock for supporting the work roll, and a roll chock. A rolling machine provided with a screw drive mechanism or a hydraulic cylinder to press the roll chock horizontally in the direction perpendicular to the roll chock always at the screw drive mechanism or the hydraulic cylinder tip. Since the crosshead or the housing liner is provided, the crosshead or the housing liner is positively pressed against the roll chock, and the gap between the roll chock and the crosshead or the housing liner is reduced to zero, and the gap is set to zero or more. Cross screw or force Is applied to the pressure cylinder, that allowed to slightly deform the housing, it is possible to reduce the vibration of the rolling mill by increasing the horizontal dynamic stiffness of the rolling mill.

Further, the rolling mill according to claim 2 of the present invention comprises:
According to claim 1, a rotatable rolling element or grease pad is mounted on the work roll crosshead or the roll chock side of the housing liner, so that the same effects as those of claim 1 can be obtained. High efficiency rolling can be realized by reducing the frictional resistance in the vertical direction.

Furthermore, the rolling mill according to claim 3 of the present invention is characterized in that:
A pair of upper and lower work rolls in a housing of a rolling mill, a roll chock that pivotally supports the work roll, and a rolling mill having a hydraulic cylinder for pressing the roll chock in a horizontal direction. A work roll crosshead or a housing liner that always presses the roll chock in the horizontal direction in a direction perpendicular to the roll chock is provided, and a properly set auxiliary piston is installed on the hydraulic cylinder to control hydraulic pressure or oil viscosity. Since the attenuation of the roll vibration is increased, the gap between the roll chock and the crosshead or the housing liner is reduced to zero, and an offset force greater than or equal to zero is applied to the cross screw or the hydraulic cylinder to remove the housing. Keep it slightly deformed , In addition to reducing the vibrations of the rolling mill by increasing the horizontal dynamic stiffness of the rolling mill, it is possible to damp the vibrations by an auxiliary piston incorporated in the hydraulic cylinder, it exerts a greater vibration damping effect.

[Brief description of the drawings]

FIG. 1 is a side view of a four-high rolling mill according to a first embodiment of the present invention.

FIG. 2 is a side view showing a modification of the rolling mill housing according to the first embodiment of the present invention.

FIG. 3 is an enlarged top view of a main part to which a rolling element or a grease pad according to the first embodiment of the present invention is applied.

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a view taken in the direction of arrows VV in FIG. 3;

FIG. 6 is a graph showing the relationship between the chock displacement and the reaction force from the housing side to the chock and the relationship between the horizontal dynamic rigidity of the rolling mill according to the amount of housing deformation according to the first embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the chock displacement and the reaction force from the housing to the chock, and the relationship between the horizontal dynamic rigidity of the rolling mill and the amount of housing deformation.

FIG. 8 is a graph showing a change in dynamic stiffness of oil with respect to an excitation frequency.

FIG. 9 is a front view of a left half of an enlarged main part of a hydraulic cylinder for pressing roll chocks according to a second embodiment of the present invention.

FIG. 10 is a graph showing a relationship between a horizontal dynamic stiffness, a dynamic stiffness, and a damping ratio of a natural vibration of a roll with respect to a hydraulic pressure in a hydraulic cylinder.

FIG. 11 is a side view showing a rolling mill according to the related art.

FIG. 12 is a side view showing a deformation of a rolling mill housing according to the related art.

FIG. 13 is an explanatory diagram showing a gap between a roll chock and a crosshead.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Strip plate material 3 Backup roll 4 Work roll 5, 6 Roll chock 7, 7 'Housing liner 8, 9 Cross screw or hydraulic cylinder 10 Pull back cylinder 11 Pressure reduction means 12, 13 Cross head 14 Pin 15, 15' Rolling body 16 Connection Part 17 Rod 18 Screw 19 Grease head 22 Main piston 23 Seal material 24 Auxiliary piston 25, 26 Oil inlet 27 Hydraulic cylinder

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Nishizaki 4-2-2 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Inventor Joh Iwatani 4-chome Kannon-Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima No. 6-22 Mitsubishi Heavy Industries, Ltd. Hiroshima Works

Claims (3)

[Claims] 1. A rolling mill having a pair of upper and lower work rolls, a roll chock for supporting the work rolls, and a screw drive mechanism or a hydraulic cylinder for horizontally pressing the roll chocks in a housing of the rolling mill. A rolling mill further comprising a work roll crosshead or a housing liner that always presses the roll chock in a direction perpendicular to the roll chock in a horizontal direction at the tip of the screw drive mechanism or the hydraulic cylinder. 2. The rolling mill according to claim 1, wherein a rotatable rolling element or a grease pad is mounted on a roll choc side of the work roll crosshead or the housing liner. 3. A rolling mill comprising: a pair of upper and lower work rolls in a housing of a rolling mill; a roll chock supporting the work roll; and a hydraulic cylinder for pressing the roll chock in a horizontal direction. At the tip of the hydraulic cylinder, it is equipped with a work roll crosshead or housing liner that always presses the roll chock in a direction perpendicular to the roll chock and in the horizontal direction, and an appropriately set auxiliary piston is installed on the hydraulic cylinder, and the hydraulic or oil viscosity is set. A rolling mill characterized by increasing the damping of the roll vibration by controlling the rolling mill.