JP2001286917A - Plate mill and plate rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate mill and plate rolling method by which the controllability of a rolled shape is improved, a good rolled shape without ripple shapes is stably secured for a long time and the lowering of productivity is not accompanied in the case that a sheet-shaped plate of >=5 mm thick is mainly taken as the object of rolling. SOLUTION: When mainly rolling the sheet-shaped plate of >=5 mm thick, a restraining device for restraining the displacement in the vertical direction of a sheet material is arranged at least on the outlet side of the plate mill and, more preferably, the outlet angle of the sheet material at the outlet of roll bite is controlled with the restraining device. Furthermore preferably, by using the plate mill which has a mechanism for supporting a work roll with a divided back-up roll divided into three or more pieces in the axial direction at least in either upper or lower parts of the rolling mill and is respectively independently provided with a load detector, a screw-down mechanism and a screw-down location detector on each divided back-up roll, light rolling is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a sheet rolling machine for producing a good product free from warpage, warpage, and undulation when rolling the above sheet material, and a rolling method using the sheet rolling machine.

[0002]

2. Description of the Related Art Generally, a sheet material called a thick plate having a thickness of 5 mm or more is rolled without tension. Although this sheet material can be rolled into a plate having a good plate shape or a plate crown by a rolling mill, the plate shape is deteriorated due to uneven cooling in a cooling process after rolling, and a warp, a warp, and a undulation are generated. There is a problem.

Conventionally, this problem has been dealt with by arranging a leveler or a hydraulic press after the cooling process to correct the problem. It is difficult to correct the plate shape. Further, after the cooling step, it is possible to correct the plate shape by performing light reduction rolling with a plate rolling mill, but in this case, it is difficult to correct the plate shape, warpage, and undulation with high accuracy.

As a plate rolling mill for solving such a problem, there is a new type intelligent plate rolling mill as disclosed in, for example, Japanese Patent Application Laid-Open No. 5-69010. This rolling mill controls the bending of the work rolls freely to control the crown or shape during rolling, and estimates the crown and the shape of the strip with high accuracy using only the information obtained from the detector of the rolling mill itself. And it is a rolling mill that can control the shape of the sheet crown and time without delay. In order to further prevent warping and undulation with such a sheet pressure machine, it is effective to apply tension to the sheet material.However, a tension applying device for a thick plate becomes a very large facility, which increases equipment costs. That is, there is a new problem that the manufacturing cost is increased.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and mainly aims at rolling a sheet-like thick plate having a thickness of 5 mm or more, and has a good plate shape and no warp or waviness. An object of the present invention is to provide a sheet rolling machine and a sheet rolling method that can ensure a stable rolling shape and have low equipment costs and low manufacturing costs.

[0006]

Means for Solving the Problems The first invention of the present invention is:
In a plate rolling machine for rolling a sheet material, a restraint device for restraining vertical displacement of the sheet material is provided on an entrance side of the sheet rolling machine, an exit side of the sheet rolling machine, or an entrance side and an exit side of the sheet rolling mill. It is a plate rolling mill characterized by being provided. The second invention is characterized in that, in the first invention, a position control device for detecting a vertical position of the sheet material and controlling the vertical position of the sheet material is disposed on either the outgoing side or the incoming side restraining device of the plate rolling mill. This is a sheet rolling mill. A third invention is characterized in that, in the first invention, a position control device for detecting and controlling the vertical position of the sheet material is provided in both the outgoing side and the incoming side restraining devices of the plate rolling mill. It is a plate rolling mill. The fourth invention is based on the first invention, and detects the vertical position of the sheet material in the restraint device on the output side of the plate rolling mill.
A plate rolling machine, comprising: a position control device for controlling the sheet rolling device; and a load detecting device for measuring a reaction force of the sheet material, provided in a restraining device on an entrance side of the plate rolling machine. . According to a fifth aspect of the present invention, in the first aspect, a position control device for detecting and controlling the vertical position of the sheet material is provided in the restraint device on the entry side of the plate rolling mill, and A sheet rolling machine, wherein a load detecting device for measuring a reaction force of the sheet material is provided in the restraining device on the side. A sixth invention is the plate rolling mill according to any one of the first to fifth inventions, wherein a mechanism for supporting a work roll by a divided backup roll divided into three or more in the axial direction at least one of upper and lower sides. A plate rolling mill comprising: a load detecting device, a rolling mechanism, and a rolling position detecting device independently provided for each divided backup roll. In the seventh invention, the work roll has a Young's modulus of 4
00 kN / mm ² or more, or Young's modulus of a plate rolling mill of claim 6, 400 kN / mm ² and roughness, characterized by using the above work rolls 0.4MyumRa.

In an eighth aspect based on the second aspect, the outflow angle of the sheet material at the roll bite outlet is detected, and the vertical position of the restraint device on the delivery side of the plate rolling mill is adjusted so that the outflow angle becomes constant. Controlling or detecting the inflow angle of the sheet material at the roll bite entrance, and controlling the vertical position of the restraint device on the entry side of the plate rolling mill so that the inflow angle is constant. is there. The ninth invention is
In the third invention, the inflow and outflow angles of the sheet material at the roll bite inlet and outlet are detected, and the vertical positions of the restraining devices on the entrance side and the exit side of the plate rolling mill are set so that the inflow and outflow angles are constant. It is a sheet rolling method characterized by controlling. A tenth invention is directed to the sheet rolling mill according to the fourth invention, wherein an outflow angle of the sheet material at the exit of the roll bite is estimated by a reaction force detected by the load detection device on the entrance side, and the outflow angle is constant. A sheet rolling method characterized by controlling a vertical position of an exit side restraining device. The eleventh invention is
In the fifth invention, the inflow angle of the sheet material at the roll bite entrance is estimated from the reaction force detected by the load detection device on the exit side, and the constraining device on the entrance side of the sheet rolling mill is controlled so that the inflow angle is constant. A sheet rolling method characterized by controlling a vertical position. According to a twelfth invention, in the sheet rolling method according to any one of the eighth to eleventh inventions, the work roll is supported by at least one of upper and lower ones divided into three or more in the axial direction by a divided backup roll. Each split backup roll is provided with a load detecting device, a rolling mechanism and a rolling position control device independently of each other, a total value of loads of the split backup rolls before starting control is obtained, and this is set as a basic load, and during rolling. A sheet rolling method, wherein the rolling position of each divided backup roll is controlled so as to have a target plate shape, and the rolling reduction is controlled so that the total load value of each divided backup roll matches the reference load. It is.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is mainly intended for rolling a sheet material having a thickness of 5 mm or more. Basically, when a sheet material is rolled by a sheet rolling machine, a sheet with no undulation or warpage and a good rolling shape can be manufactured stably and cheaply by adjusting the outflow angle of the sheet material on the exit side of the rolling machine. The conventional problem is solved by adopting the following rolling mill and rolling method.

As the rolling mill, (1) a rolling mill provided with a restraining device for restraining the vertical displacement of the sheet material at least on the exit side of the sheet rolling mill is used. Adjust the outflow angle. (2) A position control device for detecting and controlling the vertical position of the sheet material is provided in a restraining device for restraining the vertical displacement of the sheet material disposed at least on the exit side of the plate rolling mill;
Make the outflow angle of the sheet material at the roll bite outlet constant. (3) A position control device for detecting and controlling the vertical position of the sheet material is provided in a restraining device for restraining the vertical displacement of the sheet material disposed on the entrance side and the exit side of the plate rolling mill,
Make the inflow and outflow angles of the sheet material at the roll bite inlet and outlet constant. (4) A position control device for detecting and controlling the vertical position of the sheet material is provided in a restraint device for restraining the vertical displacement of the sheet material disposed on the exit side of the plate rolling mill. A restraint device for restraining the vertical displacement of the sheet material is arranged on the entry side of the rolling mill, and a load detecting device is arranged on the restraint device on the entry side of the rolling mill, and the outflow angle of the sheet material at the roll bite outlet is determined. Estimate based on the reaction force of the load detection device on the entry side, and keep the outflow angle constant.

[0010] The sheet material restraining device may be a set of guide rolls. Further, it is more preferable that the guide roll is driven. In this guide roll, it is more preferable to sandwich the sheet material with a constant force in a range that does not cause plastic deformation of the sheet material. It is preferable that a large gap between the guide rolls is set at the time of passing the sheet, and control is performed so that the desired gap is obtained immediately after the sheet is passed. Further, in order to further improve the passability of the guide roll, a guide table that operates during the passage of the guide roll may be provided on the guide roll entry side. The position control device may be a hydraulic cylinder. A load cell may be used as the load detecting device.

The rolling method is as follows: (5) The outflow angle of the sheet material at the exit of the roll bite of the plate rolling machine is detected, and the position of the restraining device on the exit side of the rolling mill is controlled so that the outflow angle becomes constant. (6) The inflow and outflow angles of the sheet material at the entrance and exit of the roll bite of the plate rolling machine are detected, and the positions of the restraining devices on the entrance and exit sides of the rolling mill are controlled so that the inflow and outflow angles become constant. . (7) The reaction force is detected by the load detecting device on the entry side of the plate rolling mill, and the outflow angle of the sheet material at the exit of the roll bite of the plate rolling machine is estimated. Control the position of the restraint.

(8) As a plate rolling mill, there is provided a mechanism for supporting a work roll with at least one of upper and lower divided backup rolls divided into three or more in the axial direction. And a load detecting device for each of the divided backup rolls independently,
A plate rolling machine provided with a rolling-down mechanism and a rolling-down position detecting device, and, using this plate rolling mill, independently provided a load detecting device, a rolling-down mechanism and a rolling-down position control device,
The total value of the loads of the divided backup rolls before the start of control is obtained, and this is used as a basic load. The rolling position of each divided backup roll is controlled so that the target plate shape is obtained during rolling, and each divided backup roll is controlled. Is a plate rolling method for controlling the rolling reduction so that the total load value of the above-mentioned load coincides with the reference load.

As described above, the controllability and control precision of the rolling shape are enhanced, and in particular, a flat plate having a flat rolling shape that is flat in the width direction and free from undulation and warpage in the rolling direction is stably manufactured.

Further, there is provided a mechanism for supporting the work roll by divided backup rolls divided into three or more in the axial direction, and each divided backup roll is provided with a load detecting device, a pressing mechanism and a pressing position detecting device independently of each other. In the above-mentioned plate rolling mill provided, the work roll has a Young's modulus of 400 kN / mm ² or more or a Young's modulus of 4 kN / mm ² or more.
By using a work roll with a roughness of at least 00 kN / mm ² and a roughness of at least 0.4 μm Ra, it is possible to stably produce a plate having a good rolled shape without waviness or warpage, and at the same time to obtain roll marks and biting The defect can be eliminated, the rolling load and the rolling torque can be reduced, and the wear of the work roll can be reduced.

In the present invention, the outflow angle of the sheet material is the angle formed by the sheet material on the exit side of the rolling mill in the counterclockwise direction in the vertical direction, and is the angle θ shown in FIG. The inflow angle is an angle formed by the sheet material on the entry side of the rolling mill in the clockwise direction in the vertical direction, and the angle γ shown in the drawing.
That is.

Hereinafter, the present invention will be described specifically. The present inventors consider that it is effective to restrain the vertical displacement of the sheet material during the rolling of the sheet material in order to stably secure a rolled shape that is flat in the plate width direction and free from waviness and warpage. In order to recognize and find the optimal conditions,
In a four-high rolling mill provided with work rolls 1 and 1 'and backup rolls 2 and 2' as shown in FIG. Guide rolls for restraining displacement are arranged on the entrance side and the exit side.

The guide roll, which is a restraining device on the entry side of the four-high rolling mill, is composed of a pair of upper and lower rolls 4 and 4 '.
Is stored within. The guide rolls can measure, adjust and raise and lower the upper and lower guide roll gaps by electric motors 20 and 20 ′ (gap measuring and adjusting devices) installed on the upper and lower sides. , 21 ', and mounted on the upper part of the upper guide roll chock and the lower part of the lower guide roll chock,
An upper load and a lower load during rolling can be detected by a load detecting device 22 '. Although not shown, the upper chock supporting the upper guide roll is supported so as not to come into contact with the lower guide roll by hydraulic pressure so as to facilitate passage of the sheet material.

The guide roll, which is a restraining device on the exit side of the four-high rolling mill, is composed of a pair of upper and lower rolls 5, 5 ', and these guide rolls are housed in an inner guide roll housing 7. . The inner guide roll housing 7 is supported by a guide roll housing 9 and can be moved up and down by upper and lower hydraulic cylinders 10 and 11 (position control devices) provided in the guide roll housing.

Although not shown, the upper chock supporting the upper guide roll is supported by hydraulic pressure so as not to contact the lower guide roll so that the sheet material can be easily passed through. In the upper hydraulic cylinder 10, pressure constant control is performed. In the lower hydraulic cylinder 11, position control is performed. Although not shown, the upper and lower guide roll gaps can be measured and adjusted by hydraulic cylinders installed above and below the inner guide roll housing 7. This hydraulic cylinder can perform position control when tightly controlling the guide roll gap, and pressure control when performing soft control. When the guide roll gap is controlled softly, the control is started at the same time when the sheet material reaches the guide roll.

A laser range finder 12 is disposed near the work rolls on the entry side and the exit side of the rolling mill. By detecting the distance between the laser range finder and the center of the width of the sheet material at the time of rolling. The position of the sheet material is obtained, and the outflow angle θ and the inflow angle γ on the sheet material exit side are calculated from the horizontal work roll center position and the detection position of the laser range finder.

That is, as shown in FIG. 8, the outflow angle θ on the sheet material exit side is calculated as follows. θ = tan ⁻¹ (h ₂ / L ₁ ) where L ₁ is the distance between the center position of the work roll in the horizontal direction and the detection position of the laser rangefinder h ₂ is the position of the sheet material at the detection position, and h ₂ = h _Three
-H ₁ (h ₃ : vertical distance between the laser range finder and the lower surface of the upper work roll, h ₁ : distance between the laser range finder and the center of the width of the sheet material during rolling) rangefinder and h ₂ is determined by detecting the distance h ₁ between the width center portion of the rolling when the sheet 8, as a result the outflow angle θ is obtained. On the other hand, for the inflow angle γ, similarly, γ = tan ⁻¹ (h
Determined by ₂ '/ L _1').

Using this four-high rolling mill, a straightening experiment according to the present invention was performed. For the sheet material, an experiment was conducted by preparing a material having a pitch L and a height h called a small wave as shown in FIG. 2 due to uneven cooling in a rapid cooling step after thick plate rolling. Note that, under the experimental conditions, the pitch L and the height h use the average value of three points, that is, the location of the center of the sheet material, and the locations of the work side and the drive side, which are the plate edges. Further, the parameter α is used to represent the small wave correction effect. This parameter α is called the residual ratio, and the residual ratio is defined as the value obtained by dividing the average height of the sheet material after light reduction straightening rolling by the average height of the sheet material before rolling, and the smaller this value is, the more the correction effect is. Indicates that it is big. Further, a guide roll gap is used as a parameter indicating the degree of restraint of the sheet material. This guide roll gap expresses how freely the sheet material can be displaced between the upper and lower guide roll gaps, and is defined as the value obtained by subtracting the sheet thickness of the sheet material before straightening under light reduction from the upper and lower guide roll gaps. I do.

[Experimental conditions] Work roll size: φ500 mm × 4000 mm Backup roll size: φ1500 mm × 4000 mm Sheet material: SS41 Plate thickness: 30 mm, 50 mm Plate width: 3500 mm Length: 40 m Plate shape: small wave material (average pitch: 3) ~ 8m, average height 6 ~
13 mm) Guide roll gap: 0.1 to 100 mm Elongation: 0.3 to 3% (lubrication: dry) Rolling speed: 30 m / min

(Experimental Example 1) The pass lines of the guide rolls on the entrance and exit sides of the rolling mill were kept constant, and the sheet material was rolled by changing the respective guide roll gaps, and the effect of straightening the small rolling under small waves was investigated. . The result is shown in FIG.

FIG. 3 shows the relationship between the small wave surviving rate α and the elongation rate λ when the sheet material is rolled and the guide roll gaps on the entrance side and the exit side. In FIG. 3, when the guide roll gap was 100 mm, the sheet material never contacted the upper guide rolls on the entrance and exit sides of the rolling mill. That is, the guide roll gap of 100 mm is the same as the absence of the upper guide rolls on the entrance side and the exit side of the rolling mill.

FIG. 3 shows that when the sheet material having a small wave shape is straightened by light rolling, the guide roll gap at the entrance side is 100 mm and the guide roll gap at the exit side is 0.1 mm.
Although the residual ratio is reduced along with the elongation, the residual ratio is 90% when the elongation is 1% or less with the entrance side guide roll gap of 0.1 mm and the exit side guide roll gap of 100 mm.
９５95%. In other words, the guide rolls on the exit side of the rolling mill are indispensable for correcting the small wave shape of the sheet material, but the guide rolls on the entry side of the rolling mill are not as effective as the guide rolls on the exit side of the rolling mill, but are not as effective as the guide rolls on the exit side of the rolling mill. The guide roll alone has a maximum improvement effect of about 10%. And it became clear that the smaller the exit side guide roll gap, the greater the correction effect.

(Experimental Example 2) Using the four-high rolling mill shown in FIG. 1, the guide roll gap on the entry side of the rolling mill was 100 mm, that is, the exit side guide roll gap was 0.1 mm without using the entry side guide roll. And rolled at 1% elongation,
The outflow angle at the exit of the roll bite of the sheet material was detected, and the exit-side guide roll position was controlled so that the value was constant. The resulting profile (measured off-line) in the rolling direction at the center of the sheet width of the sheet material is shown in FIG. FIG. 4 (a) shows the material profile before rolling, and FIG. 4 (b) shows the case where the exit guide roll is not moved. The outflow angle is detected and the exit guide roll is adjusted so that the value becomes constant. FIG. 4C shows the case where the control is performed.

Thus, by detecting the outflow angle at the exit of the roll bite and controlling the position of the exit side guide roll so that the value becomes constant, small waves can be improved by 90% or more and a great effect can be obtained. Was revealed.

(Experimental Example 3) Using the four-high rolling mill shown in FIG. 1, the effect of controlling the inflow angle of the guide roll on the entrance side was examined by reversing the rolling direction in Experimental Example 2. That is, the guide roll gap on the entry side of the rolling mill was set to 0.1 mm, the guide roll gap on the exit side was set to 100 mm, and the roll was rolled at an elongation of 1%. Was detected, and the position of the entry-side guide roll was controlled so that the value became constant. As a result, although not shown, the result was better than the result of rolling with the guide roll gap on the entrance side and the exit side of the rolling mill shown in Experimental Example 1 being 100 mm.

(Experimental Example 4) Using the four-high rolling mill shown in FIG. 1, the guide roll gap on the entry side of the rolling mill was -0.1 m.
m, the exit guide roll gap is set to -0.1 mm, and the roll is rolled at an elongation of 1%. The exit angle of the sheet material at the roll bite exit is estimated, and the exit guide roll is adjusted so that the value is constant. Controlled the position. Here, a method of estimating the outflow angle of the sheet material at the roll bite outlet will be specifically described.

[0031] by the load cell 22, 22 'attached to the bottom of the guides on the guide roll chocks in the housing of the upper and lower guide roll chock entry side shown in FIG. 9, for detecting the load P ₁ and P ₂ during rolling. At that time, the position of the sheet material 8 immediately below the laser range finder is detected by the laser range finder 12 attached to the delivery side of the rolling mill, and the delivery side outflow angle θ is detected. Flat if you rolled without flat sheet warpage and undulation by the sheet material, essentially acting at the bottom of the upper guide roll chocks force P ₁ and the lower guide roll chock acting on the top of the inlet side housing force P ₂ which is equal.

As shown in FIG. 9, when the outflow angle θ of the sheet material is going to bend upward with a positive value, but is constrained by the exit guide roll, the sheet material is pushed and bent downward at the roll bite exit. The desired moment force acts. Due to the moment force on the roll bite exit side, a moment force is applied to the sheet material at the roll bite entrance to push and bend the material upward. The sheet material tends to bend upward at the entry side of the rolling mill due to the moment force applied to the roll bite entrance, but the displacement is restricted because the sheet material is restricted by the entry side guide roll. As a result, the load P1 detected by the upper load cell increases, and a difference occurs between the loads of the upper and lower load cells. When the outflow angle θ on the roll bite exit side is negative, a phenomenon opposite to the above-described phenomenon occurs, and finally the load P2 detected by the lower load cell increases, and the difference between the loads of the upper and lower load cells is different. Will occur. The present invention utilizes this principle. According to this method, the outflow angle of the sheet material on the roll bite exit side can be estimated without a laser range finder on the roll bite exit side.

The load difference obtained above and ΔP = P ₁ −P
₂ shows the relationship between the delivery side outlet angle calculated by detecting the position of the sheet material located immediately below the laser distance meter laser distance meter mounted on the delivery side of the rolling mill θ in Figure 10 (a). However,
FIG. 10A shows a case where the plate thickness, the plate width, and the material are the same. From the figure, it became clear that the load difference between the upper and lower guide rolls and the outflow angle of the sheet material at the exit of the roll bite can be linearly approximated. Therefore, an experiment is performed for each material, plate width, and plate thickness, and a linear relationship as shown in FIG. 10A is held as a table, and based on this, the outflow outflow angle θ ′ is estimated from the difference in load between the upper and lower guide rolls. You may. The position of the exit guide roll may be controlled by the amount of L ₁ tan θ ′ based on the estimated value of θ ′.

If it is difficult to have a table for each material, width and thickness, the thickness (h) and the width (W), the 0.2% proof stress (σy) of the material and the load difference (△ P = P ₁ −P
_{Using 2} ), we have found that it can be better organized by the parameter Ω shown in the following equation. Ω ≒ C · △ P · σy / W / h ^{3 In the} above equation, C is a constant and is determined by multiple regression. When the material, width and thickness are changed, the parameter Ω obtained by the above preliminary experiment method and the position of the sheet material directly below the laser distance meter are detected by the laser distance meter attached to the exit side of the rolling mill. FIG. 10B shows the relationship between the outlet-side outflow angle θ obtained as described above. Although the variation slightly increases as compared with FIG. 10 (a), the detection value of the load difference of the entrance-side guide roll, the sheet thickness, the sheet width, and the material can be obtained without using many tables by using the parameter Ω. Of the sheet material on the roll bite exit side can be estimated using the known amount of proof stress.

Using the four-high rolling mill shown in FIG. 1 in such a manner, the guide roll gap on the entry side of the rolling mill is set to -0.0.
1 mm, the exit guide roll gap was set to -0.1 mm, and the roll was rolled at an elongation of 1%. The exit angle of the sheet material at the roll bite outlet was estimated, and the exit guide roll was adjusted so that the value was constant. FIG. 5 shows the profile (measured off-line) in the rolling direction at the center of the sheet width of the sheet material as a result of the experiment by controlling the position of. The material profile before rolling is shown in FIG. 5 (a), and the case where the exit guide roll is not moved is shown in FIG. 5 (b). The outflow angle is estimated and the exit guide roll is adjusted so that the value becomes constant. FIG. 5C shows the case where the control is performed.

Thus, during light rolling, the load is detected by the entrance guide roll, the outflow angle at the exit of the roll bite is estimated, and the position of the inner guide housing of the exit guide roll is controlled so that the value becomes constant. By doing so, it became clear that the small wave was improved by 80% or more and a great effect was obtained.

In Experimental Examples 1 and 2,
Although the guide rolls on the entry side and the exit side were driven without driving, it is more preferable to drive the guide rolls. Further, although not shown in FIG. It is more preferred to equip an elevating guide table for guiding into the gap of the side guide roll.

Further, a rolling method using a divided backup roll divided into at least one of the upper and lower parts in the axial direction into three or more parts will be described with reference to FIG. This example
This is a case where the present invention is applied to a plate rolling machine for rolling a sheet material having a thickness of 5 to 60 mm and a width of 2000 to 3800 mm. The plate rolling mill of this example has a mechanism for supporting a work roll with divided backup rolls divided into three or more in the axial direction on both the upper and lower sides, and a load detecting device and a pressing-down mechanism are independently provided for each divided backup roll. And a rolling mill provided with a rolling position detecting device.

In this rolling mill, the upper and lower inner housings 15 which are moved up and down by the main pressing device 13 have a mechanism for supporting the upper and lower work rolls 17 by divided backup rolls 18 and 19 divided into three or more in the axial direction. Yes,
Each divided backup roll 18a to 18g, 19a
To 19h are independently provided with a load detecting device, a rolling-down mechanism, and a position detecting mechanism (not shown). Further, a work roll chock 16 is provided in the inner housing.
Is provided.

Further, a restraining device is provided on the exit side of the rolling mill. In this example, a guide roll serving as the restraining device is constituted by a pair of upper and lower rolls 5 and 5 '. It is housed in the roll housing 7. The inner guide roll housing 7 is supported by a guide roll housing 9, and can be moved up and down by upper and lower hydraulic cylinders 10 and 11 provided in the guide roll housing 9. The upper hydraulic cylinder 10 performs constant pressure control, and the lower hydraulic cylinder 11 performs position control. Although not shown, the upper and lower guide roll gaps can be measured and adjusted by electric motors installed above and below the inner guide roll housing 7.

A laser distance meter 12 is disposed near the work roll 17 on the exit side of the rolling mill. As shown in FIG. 8, the distance between the laser distance meter and the center of the width of the sheet 8 during rolling is increased. by detecting the h _1, the position of the sheet material h
₂ calculated to detect the outflow angle θ of the sheet material exit side from the detection position L ₁ of the horizontal work roll center position and the laser rangefinder. The sheet material 8 is carried into and out of the rolling mill by a plurality of transport rolls 14 provided on the entrance and exit sides of the rolling mill.

Next, in the present invention, there is provided a mechanism for supporting a work roll by the above-mentioned divided backup rolls, and each of the divided backup rolls is independently provided with a load detecting device, a pressing-down mechanism and a pressing-down position detecting device. In the provided plate rolling mill, by defining the Young's modulus and / or the roughness of the work roll, torque transmission can be improved, and at the same time, roll marks and defective biting can be eliminated, thereby significantly reducing roll wear. .

That is, in the prior art, the Young's modulus of a work roll is about 210 kN / mm ² and the initial roll roughness is 0.5 μN.
mRa or more.
00 kN / mm ² or more and roll roughness is 0.4 μm Ra or more. When the work roll was rolled with a Young's modulus of 400 kN / mm ² or more, the contact arc length was reduced, the rolling load and rolling torque were reduced, and almost no roll mark was generated. Moreover, it was confirmed that the wear of the work roll itself was significantly reduced as compared with the conventional roll. For this reason, the initial roughness can be reduced and the roll can be used longer than the conventional roll. Further, by reducing the initial roughness, the coefficient of friction is reduced, and the rolling load and the rolling torque are also reduced. On the other hand, when the Young's modulus of the work roll is 400 k
When rolling was performed at a roughness of 0.4 μm Ra or more while maintaining the N / mm ² or more, the slip occurrence rate of the sheet material was 0%, and it was confirmed that a good biting property was exhibited. Of course, not only specifying both the Young's modulus and the roughness of the work roll as described above, but specifying only the Young's modulus within the above range was sufficiently effective.

(Example) In order to evaluate the seventh invention of the present invention, the work roll is supported by divided backup rolls divided into eight and seven parts in both the upper and lower directions shown in FIG. 6B. Using a plate rolling mill provided with a load detecting device, a pressing mechanism and a pressing position detecting device for each of the divided backup rolls independently. so,
The exit guide roll gap is set to 0.1 mm, the outflow angle of the sheet material at the roll bite exit is detected based on the distance detected by the laser distance meter, and the exit guide roll is adjusted so that the value becomes constant. Controlled position.

The plate shape is estimated from the load distribution between the work roll and the backup roll detected by each divided backup roll and the position of the backup roll to estimate the plate shape immediately below the work roll. Dynamic control was performed by adjusting the position of the backup roll.

The dynamic control method was performed by the method disclosed in Japanese Patent Application Laid-Open No. Hei 6-262228 filed by the inventors. That is, the load acting on the i-th divided backup roll is q _i , the load between the rolled material and the work roll corresponding to the position is p _i , the deformation matrix of the work roll axis deflection is K ^W _ij , the deformation of the backup roll system matrix the K ^B _ij, the work roll profile expressed in the type of roll crown C ^W _i, divided backup roll profile of C ^B _i, when the deflection heart upper work roll axis and y ^W _i, divided backup roll and the work roll Equation (1) is obtained from the matching condition. ^{_{y W i = K B ij q}} j + C W i + C B i (1)

In the equations of this specification, when there is a repetition of the same subscript, it is expressed using Einstein's summation rule. Although K ^B _ij is the influence coefficient matrix representing the displacement of the i split backup rolls when the unit load is applied to the j-th divided backup rolls, where the deformation and the work roll - split backup rolls of the housing It shows a deformation matrix including flat deformation of both rolls due to contact. _{^{K B ij, K W ij,}} y W i is all to extract only the relative position from the mill center.

On the other hand, the upper work roll deflection is expressed by the following equation (2) using the deformation matrix K ^W _ij and the rolling load distribution p _i acting between the rolled material and the work roll. y ^W _i = K ^W _ij (p _j −q _j ) (2) By erasing y ^W _i from equations (1) and (2) and rearranging, equation (3) is obtained. ^{_{q i = [K B + K}} W] at _{^{-1 ij (K W jk p k}} -C W j -C B j) (3) above the right-hand side of the ^{equation, [K W + K B]} -1 ij is K ^W _ij + K ^{This is} the inverse matrix of ^B. By the way, the rolling load p _i is generally equal to the entry side thickness H, the exit side thickness h, the deformation resistance k, the friction coefficient μ, the average entry side tension σ _b , the average exit side tension σ _f , and the elongation-strain difference expressing the plate shape. It is a function of Δε and is given by equation (4). p _i = p _i (H, h, k, μ, σ _b , σ _f , Δε) (4) Here, K and μ in the roll bite are almost constant in the sheet width direction, and are determined by calculation and experiment. Can be
The entry side plate thickness H, the exit side plate thickness h, the average entry side tension σ _b, and the average exit side tension σ _f are given by inputting desired rolling conditions.

Therefore, by substituting the target elongation-strain difference Δε from the equation (4), the rolling load p _i for obtaining a desired shape can be obtained. By substituting the rolling load p _i into equation (3), the load q _i of each divided backup roll for obtaining a desired shape is obtained. Therefore, conventionally, the displacement of each divided backup roll is generally adjusted while checking the load of each divided backup roll such that the load of each divided backup roll matches q _i .

[Experimental conditions] Upper and lower work roll size: φ300 mm × 4000 mm Upper and lower seven-part side backup roll size: φ750 mm ×
3500mm Top and bottom 8 side backup roll size: φ750mm ×
4000mm Each divided backup roll width: 500mm Sheet material: SS41 Plate thickness: 30mm Plate width: 3800mm Length: 45m Plate shape: Small wave material (average pitch: 4 to 7m, average height 3 to 3)
10mm) Elongation: 1.0% (Lubrication: Dry) Rolling speed: 40 m / min

FIG. 7 shows the experimental results. FIG. 7A shows the distribution of steepness in the rolling direction measured after the above-described experiment, where a positive value indicates an ear wave and a negative value indicates a tendency toward medium elongation. It can be seen that the plate shape is controlled to be almost flat according to the present invention. FIG. 7 (b) shows the distribution of the degree of survival of the ripples in the rolling direction measured after the above-described experiment, and it is clear that the ripples are drastically improved by the present invention.

Under the above experimental conditions, the work load
Young's modulus 400 kN / mm ^Two, Roughness 0.53μ
After rolling 288 times using mRa rolls,
Mark and the number of occurrences of poor biting and slippage are 0.
And the average rolling torque reduction effect is about 6%
Degree and the effect of reducing the average work roll wear
A total improvement of 96% was observed.

According to the present invention, when a sheet-like thick plate having a thickness of 5 mm or more is to be rolled, a restraining device for restraining the vertical displacement of the sheet material is provided at least on the exit side of the plate rolling mill. And, more preferably, the outflow angle of the sheet material at the roll bite outlet is controlled by the restraining device,
More preferably, at least one of the upper and lower rolling mills has a mechanism for supporting the work rolls by divided backup rolls divided into three or more in the axial direction, and each divided backup roll independently has a load detection device, By using a plate rolling mill equipped with a mechanism and a rolling position detection device, the rolling reduction called the small wave shape inherent to a thick plate is reduced with a small capital investment by using a plate rolling mill provided with a good rolling shape over a long period of time. Stability can be ensured. The results of the present invention are collectively shown in Table 1 on the next page.

[0054]

[Table 1]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a structural example of a plate rolling mill and a sheet material restraining device used in an experimental example.

FIG. 2 is an explanatory diagram showing a relationship between pitch and height of small waves of a sheet material.

FIG. 3 is an explanatory diagram showing a relationship among a small wave surviving rate α and an elongation rate λ obtained in Experimental Example 1, and a roll gap on the entrance and exit sides.

4A and 4B are explanatory diagrams showing profiles in the rolling direction at the center of the sheet width of the sheet material obtained in Experimental Example 2, wherein FIG. 4A is a material profile before rolling, and FIG. Plate profile after rolling when the roll position is not moved,
(C) Drawing is an explanatory view showing a plate profile at the time of controlling the exit side guide roll position at the time of rolling.

FIGS. 5A and 5B are explanatory diagrams showing profiles in the rolling direction at the center of the sheet width of the sheet material obtained in Experimental Example 3, in which FIG. 5A is a material profile before rolling, and FIG. Plate profile after rolling when the roll position is not moved,
(C) Drawing is an explanatory view showing a plate profile at the time of controlling the exit side guide roll position at the time of rolling.

FIG. 6 is an explanatory view showing a structural example of a plate rolling mill and a sheet material restraining device used in an embodiment of the present invention.

FIG. 7 is an explanatory diagram showing the steepness in the rolling direction and the residual ratio at the center of the sheet width of the sheet material obtained in the example of the present invention, and (a).
FIG. 4 is an explanatory diagram showing steepness, and FIG.

FIG. 8 is an explanatory diagram for calculating an outflow angle and an inflow angle of a sheet material.

FIG. 9 is an explanatory view of a rolling mill in which an experiment was conducted on a method of estimating the outflow angle of the sheet material on the exit side of the roll bite from the load difference between the upper and lower load cells attached to the entrance guide roll according to the present invention.

FIG. 10 is an explanatory view showing the relationship between the load difference between the upper and lower load cells attached to the entrance guide roll and the outflow angle of the sheet material on the exit side of the roll bite, wherein (a) shows only sheet materials of the same steel type and size. FIG. 4B is a diagram in the case of rolling, and FIG. 4B is a diagram in the case of rolling a sheet material of different steel types and multiple sizes.

[Explanation of symbols]

 1, 1 'work roll 2, 2' backup roll 3 housing post 4, 4 'restraining device (rolling machine entrance side guide roll) 5, 5' restraining device (rolling mill exit side guide roll) 6 guide roll housing 7 inner guide Roll housing 8 Sheet material 9 Guide roll housing 10, 11 Position control device (hydraulic cylinder) 12 Laser distance meter 13 Main pressure lowering device 14 Transport roll 15 Inner housing 16 Work roll chock 17 Work roll 18, 19 Backup roll 20, 20 'Gap measurement・ Adjustment device 21, 21 'Chock 22, 22' Load detection device (load cell)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21B 37/00 BBJ B21C 51/00 F 37/38 B21B 37/00 BBJ B21C 51/00 117B

Claims (12)

[Claims] 1. A plate rolling machine for rolling a sheet material,
A plate rolling machine characterized in that a restraining device for restraining a vertical displacement of a sheet material is provided on an entrance side of a sheet rolling mill, an exit side of a sheet rolling mill, or an entrance side and an exit side of a sheet rolling mill. 2. The position control device according to claim 1, wherein a position control device for detecting and controlling the vertical position of the sheet material is provided in one of the restraining devices on the outgoing side or the incoming side of the plate rolling mill. Plate press. 3. The plate according to claim 1, wherein a position control device for detecting and controlling the vertical position of the sheet material is provided on both the exit side and the entrance side of the plate rolling mill. Rolling mill. 4. A position control device for detecting and controlling a vertical position of a sheet material is provided in a restraining device on an output side of a plate rolling mill.
The plate rolling machine according to claim 1, wherein a load detecting device for measuring a reaction force of the sheet material is provided in a restraining device on an entrance side of the plate rolling machine. 5. A position control device for detecting and controlling a vertical position of a sheet material is provided in a restraint device on an entrance side of a plate rolling mill,
The plate rolling machine according to claim 1, wherein a load detecting device for measuring a reaction force of the sheet material is provided in a restraint device on an output side of the plate rolling machine. 6. A mechanism for supporting a work roll with divided backup rolls divided into at least one of upper and lower parts in an axial direction into three or more divisions, wherein each of the divided backup rolls independently includes a load detecting device, a pressure reduction mechanism, The plate rolling mill according to any one of claims 1 to 5, further comprising a rolling position detecting device. 7. The work roll has a Young's modulus of 400.
kN / mm ² or more, or a plate rolling mill according to claim 6, Young's modulus, characterized in that the 400 kN / mm ² and roughness uses more work rolls 0.4MyumRa. 8. When a sheet material is rolled by the plate rolling mill according to claim 2, an outflow angle of the sheet material at a roll bite outlet is detected, and the outflow angle of the sheet rolling machine is adjusted so that the outflow angle becomes constant. Controlling the vertical position of the side restraint device or detecting the inflow angle of the sheet material at the roll bite inlet, and controlling the vertical position of the inlet side restraint device of the sheet rolling mill so that the inflow angle becomes constant. A sheet rolling method characterized by the following. 9. When the sheet material is rolled by the sheet rolling machine according to claim 3, the inflow and outflow angles of the sheet material at the inlet and the outlet of the roll bite are detected so that the inflow and outflow angles become constant. And a vertical position of a restraining device on an entrance side and an exit side of a sheet rolling mill. 10. When the sheet material is rolled by the plate rolling mill according to claim 4, the outflow angle of the sheet material at the exit of the roll bite is estimated from the reaction force detected by the load detector on the input side, and the outflow angle is determined. A sheet rolling method, comprising controlling a vertical position of a restraining device on an exit side of the sheet rolling mill so that an angle becomes constant. 11. When the sheet material is rolled by the plate rolling mill according to claim 5, the angle of inflow of the sheet material at the roll bite inlet is estimated from the reaction force detected by the load detection device on the exit side, and the inflow angle is determined. A sheet rolling method comprising controlling a vertical position of a restraining device on the entry side of the sheet rolling machine so that the angle becomes constant. 12. The sheet rolling method according to any one of claims 8 to 11, wherein the work rolls are supported by divided backup rolls divided into three or more in the axial direction at least one of upper and lower sides. Each of the divided backup rolls is provided with a load detecting device, a rolling mechanism and a rolling position control device independently of each other. The rolling position of each divided backup roll is controlled so that the target plate shape is formed therein, and the reduction is controlled such that the total load of each divided backup roll matches the reference load. Method.