JP2002346615A - Plate rolling mill with zero adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate rolling mill with a zero adjustment method which enables a short-time high accuracy zero adjustment and improves an estimation accuracy of a plate shape during rolling. SOLUTION: This is a plate rolling mill featuring that, at least either of upper and lower roll assemblies has a mechanism a backup roll divided into more than three divisions in the axial direction supports a work roll, an independent load detector and a screw down device are arranged on the respective divided backup roll, and a device to add and/or measure a working load and a distance between the inner housings at both work and drive sides is arranged in at least either of upper and lower inner housings of this plate rolling mill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism in which at least one of the upper and lower roll assemblies has a mechanism for supporting a work roll by divided backup rolls divided into three or more in the axial direction. The present invention relates to a sheet rolling mill in which an independent load detecting device and a rolling-down device are arranged, and a method of adjusting a zero point of the sheet rolling mill.

[0002]

2. Description of the Related Art In recent years, a load distribution of a split backup roll is detected and a load distribution between a rolled material and a work roll is estimated as in a plate rolling mill described in Japanese Patent Application Laid-Open No. 05-48375. A rolling mill capable of estimating a later sheet crown and sheet shape with high accuracy has been attracting attention. Among this type of rolling mill, Japanese Patent Application Laid-Open No. 06-262221 discloses a cluster type rolling mill having a vertically asymmetric roll arrangement as shown in FIG. Such a rolling mill is capable of controlling a sheet crown, a sheet shape, and the like with high accuracy, and is therefore extremely advantageous for producing a sheet rolled material requiring strict shape quality.

In order to enable such excellent control, an initial setting called zero point adjustment is important. The zero point adjustment is to adjust the rolling position of each divided backup roll so that a desired load distribution of the divided backup roll is obtained by tightening the kiss roll, and use the reduced position as an origin (reference) in the rolling control. Therefore, if the accuracy of the zero point adjustment is poor, the estimation accuracy of the load distribution between the rolled material and the work roll is deteriorated.

[0004]

As described above, one of the upper and lower roll assemblies is a mechanism for supporting a work roll by a split backup roll divided into three or more in the axial direction. In a sheet rolling mill in which an independent load detecting device and a pressure reducing device are arranged, zero point adjustment is very important.

In this rolling mill, when the rolling position of one split backup roll is changed, the load of all split backup rolls changes. Therefore, this operation requires skill, and the zero point adjustment has been manually performed by a skilled operator for a long time. There was a demand for performing this operation automatically and in a short time.

Further, even if a desired load distribution is obtained by the above-mentioned zero point adjustment, leveling of the upper and lower work rolls in the plate width direction is not necessarily guaranteed. This is a mechanism in which a work roll is supported by divided backup rolls divided into three or more in the axial direction. In a plate rolling mill in which an independent load detecting device and a pressing-down device are arranged in each divided backup roll, the problem is as follows. It was serious.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for adjusting the zero point and a sheet rolling mill for solving the above-mentioned problems. A plate rolling mill in which a roll assembly supports a work roll by divided backup rolls divided into three or more in an axial direction, and each divided backup roll is provided with an independent load detecting device and a pressing-down device. In performing the zero point adjustment of the plate rolling mill by tightening the kiss roll, each split backup roll is individually pressed in advance by using the plate rolling machine, and the values of the pressing amount and the change in the load distribution are investigated to reduce the rolling reduction. And the load distribution change amount, and store the roll assembly so that the sum of the divided backup roll loads becomes the desired load. Controlling the load of the inner housing, measuring the load and the rolling position of each divided backup roll at that time, obtaining the load difference between each divided backup roll load set in advance, and using the obtained load difference and the above relational expression. A zero point adjusting method for a sheet rolling mill, wherein a rolling position correction amount of each divided backup roll is calculated, and a rolling position of each divided backup roll is controlled based on the reduced position correction amount. Claim 2
Either the upper or lower roll assembly is
A work roll is supported by divided backup rolls that are divided into more than one. In a plate rolling machine in which an independent load detecting device and a pressing-down device are arranged for each divided backup roll, the plate rolling is performed by tightening a kiss roll. When adjusting the zero point of the mill, the individual backup rolls are individually pushed in advance using the plate rolling mill, and the values of the pushing amount and the load distribution change are investigated, and the relational expression between the rolling reduction amount and the load distribution change amount is obtained. The load of the inner housing containing the roll assembly is controlled so that the load of the divided backup roll as one reference becomes a desired load, and the load of each divided backup roll at that time and Measure the rolling position, find the load difference with each preset split backup roll load,
Based on the obtained load difference and the relational expression, the roll-down position correction amounts of all the backup rolls other than the reference split backup roll are calculated, and all the splits except the reference split backup roll are calculated based on the roll-down position correction amount. A method for adjusting a zero point of a plate rolling mill, comprising controlling a rolling position of a backup roll. Claim 3 of the present invention is that at least one of the upper and lower roll assemblies is divided into three or more in the axial direction. Is a mechanism for supporting the work rolls by the divided backup rolls, and each of the divided backup rolls is provided with an independent load detecting device and a rolling-down device in the inner housing, and at least one of the upper and lower sides of the plate rolling mill. The load between the inner housing and the inner A plate rolling mill in which an apparatus for adding and / or measuring the distance between the housing and the load between the inner housing and the work roll chock and the distance between the inner housing and the work roll chock is arranged. Claim 4 of the present invention In performing the zero point adjustment according to claim 1 or 2, in the sheet rolling mill according to claim 3, before the kiss roll is tightened, the load between the inner housing and the distance between the inner housings or the load between the inner housing and the work roll chock and the load between the inner housing and the work roll chock. With a roll gap secured by a device for adding and / or measuring the distance between the inner housing and the work roll chock, the load between the inner housing and the distance between the inner housings on both the work side and the drive side or the distance between the inner housing and the work roll choke are maintained. Distance between the load and the inner housing and the work roll chocks click is zero point adjustment method of a plate rolling mill, characterized by adjusting pressing position of the main housing so that the value desired.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. 1 and 2 are schematic views showing an example of a rolling mill to which the method of the present invention is applied. FIGS. 1 and 2 (a) are side views, and FIGS. 1 and 2 (b) are top views. FIG. 1 shows an asymmetric type rolling mill and FIG. 2 shows a symmetric type rolling mill. 1 and 2, the upper roll assembly has a mechanism for supporting the work roll 1 by divided backup rolls 3A to 3C and 4A to 4D divided into seven in the axial direction, and each of the divided backup rolls 3A to 3C. , 4A to 4D, a load detecting device and an independent split backup roll pressing device are disposed independently. In FIG. 1, a lower work roll 2 and a lower backup roll 5 are arranged. In FIG. 2, the lower split backup roll has the same structure as the above-described upper work roll and upper split backup roll, and is vertically symmetrically arranged. ing. Although not shown,
These split backup rolls and the like are housed in an inner housing, and the inner housing is housed in a main housing. Upper work roll diameter is 24
0 mm and the diameter of the upper split backup roll is 500 mm.

In FIG. 1, the lower work roll diameter is 800
mm and the diameter of the lower backup roll is 1300 mm. still,
In FIG. 2, the diameter of the lower work roll is 240 mm, and the diameter of the lower split backup roll is 500 mm. Although not shown, the main housing is provided with an electric press-down device for individually balancing the work side and the drive side of the inner housing in which the upper split backup roll is stored, and a lower backup roll chock or a lower split backup roll. A hydraulic pressure reduction device is provided for individually reducing (rolling force) the work side and the drive side of the housed inner housing.

Using these rolling mills, a skilled operator adjusts the zero point, pushes each of the divided backup rolls independently, first examines the amount of pushing and the change in load distribution, and calculates the amount of reduction and load distribution. A coefficient in the matrix of Expression (1) is obtained as a relational expression with the amount of change. In the equation (1), △ Pi (i = 1 to 7) indicates the rolling position of each divided backup roll from the reference state to △ δi (i = 1 to 7).
7) Indicates the amount of load change of each divided backup roll when pushed.

(Equation 1)

In the first aspect of the present invention, the inner housing or the backup roll chock containing the lower divided backup roll is controlled by the hydraulic pressure reduction device so that the total load of the divided backup rolls becomes the target load. I do. The measured value of the load of each divided backup roll at that time is Pei (i = 1 to 7), and the rolling position is δ.
Assuming that ei (i = 1 to 7) and the target measured value of the load of each divided backup roll is Pai (i = 1 to 7), ΔPi = Pei−Pai (2) (3) is obtained.

(Equation 2) Based on the obtained value (△ δi), the target position (δai) of each divided backup roll is obtained by Expression (4). δai = δei + △ δi (4) The position of each divided backup roll may be controlled based on this value.

In the second invention of the present invention, the inner housing or the backup roll chock accommodating the lower divided backup roll is controlled by the hydraulic pressure reduction device such that the load of the reference divided backup roll becomes the target load. I do. For simplicity, an example based on the fourth divided backup roll is shown here. The rolling position of the fourth divided backup roll is fixed at, for example, a half position of the amount that can be reduced, and is set as the target load Pa4.

At this time, the measured value of the load of each divided backup roll is Pei (i = 1 to 3, 5 to 7), the rolling position is δei (i = 1 to 3, 5 to 7), The measured value of the load of the split backup roll is Pai (i = 1 to
3, 5-7), then {Pi = Pei−Pai,
Since δ4 = 0, equation (5) is obtained from equation (1).

(Equation 3)

Equation (6) is obtained from the above equation.

(Equation 4) With the obtained value (△ δi), the target position (δai) of each divided backup roll is δai = δei +
It is obtained by calculating Δδi, and the position of each divided backup roll may be controlled based on this value. In this example, the roll-down position of each divided backup roll after the zero point adjustment according to the second invention is a position that is approximately half of the amount that can be reduced.

The third and fourth aspects of the present invention will be described. FIG. 3 shows the asymmetric type rolling mill shown in FIG. 1, in which (a) is a front view and (b) is a side view. In FIG. 3, the upper work roll is accommodated in an inner housing, and the inner housing 6 has a work side and drive sides 6A, 6A '. The lower work roll 2 is supported by chocks 7A, 7A 'arranged on the work side and the drive side.
An inner housing and a lower work roll chock load applying device 8A, 8A 'are arranged on the drive side and the work side of the inner housing 6, and a hydraulic cylinder is used in this example. The hydraulic cylinder has a built-in pressure sensor and position sensor, and can measure the load between the inner housing and the lower work roll chock and the distance between the inner work and the lower work roll chock.

Before tightening the kiss roll, a reference load is applied between the inner housing and the work roll chock with the roll gap being opened, and the distance is measured. Then, so that the distance between the inner housing of the work side and the drive side and the work roll chock are equal,
The balance between the work side and the drive side of the inner housing is adjusted by adjusting the electric reduction position of the work side and the drive side of the main housing.

As a result, the level of the work roll is secured, and normal zero adjustment can be performed. Later work is the first
And are the same as those described in the second invention. Thereby, it is possible to prevent the zero-point adjustment of a slight hit as shown in FIGS. 4 (c) and 4 (d).
It is possible to maintain a stable split backup roll level as shown in FIG.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described using a plate rolling mill shown in FIG. The coefficient in the matrix of the equation (3) was obtained by an experiment in advance. First, the work side and the drive side were subjected to a force of 20 tonf / chock with the roll gap opened using a load applying device between the chock, and the distance between the inner housing of the work side and the drive side and the work roll chock was measured. The electric reduction position of the work side and the drive side of the main housing was adjusted so that the level of the inner housing did not have the difference between the chocks.

Thereafter, the load of the inter-chock load applying device was removed, and the entire reduction was applied by the hydraulic reduction devices on the work side and the drive side of the main housing so that the total load of each divided backup roll became 240 tons (work). Side and drive side tightening amounts are equal). The zero-point adjustment was performed according to the first invention of the present invention, with the load target on the three-split side set to 40 tonf and the load target on the four-split side set to 30 tonf. As a result, a skilled operator can adjust the zero point, which conventionally took about one hour, in less than 10 minutes.

[0020]

By applying the above-described sheet rolling mill of the present invention and the zero-point adjusting method using the sheet rolling mill, zero-point adjustment can be performed with high accuracy in a short time. The accuracy of estimating the plate shape can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of an asymmetric type of a sheet rolling mill to which the method of the present invention is applied, (a) is a side view, and (b) is a top view.

FIG. 2 is a schematic view of a symmetric type of a sheet rolling mill to which the method of the present invention is applied, (a) is a side view, and (b) is a top view.

3 is a schematic view of an asymmetric type of the sheet rolling mill shown in FIG. 1, wherein (a) is a front view and (b) is a side view.

4 (a) and 4 (b) show the level of the work roll and the split backup roll of the present invention, and FIGS. 4 (c) and 4 (d) show the levels of the prior art work roll. It indicates the level of the split backup roll.

[Explanation of symbols]

 1: Small diameter work roll 2: Large diameter work roll 3: Split backup roll (3 split) 4: Split backup roll (4 split) 5: Backup roll 6A, 6A ': Part of inner housing chock 7A, 7A': Bottom Work roll chocks 8A, 8A ': Apparatus for applying load between chocks

Claims (4)

[Claims] 1. A mechanism in which one of the upper and lower roll assemblies supports a work roll by a split backup roll divided into three or more in an axial direction, and each split backup roll has an independent load detecting device. In a plate rolling mill in which a rolling reduction device is arranged, when zero-point adjustment of the plate rolling mill is performed by tightening a kiss roll, each divided backup roll is individually pushed in advance by using the plate rolling machine, and the pushing amount and the load distribution. Investigate the value of the change and create a relational expression between the amount of reduction and the amount of change in the load distribution, and the inner housing housing the roll assembly so that the total load of the divided backup rolls becomes the desired load. In addition to controlling the load, measure the load and rolling position of each split backup roll at that time, and set each split backup roll set in advance. Determine the load difference with the backup roll load, from the obtained load difference and the above relational formula, calculate the amount of roll-down position correction of each split backup roll, and based on the amount of roll-down position correction, calculate the roll-down position of each split backup roll. A method for adjusting a zero point of a sheet rolling mill, characterized by controlling. 2. A mechanism in which one of the upper and lower roll assemblies supports a work roll by a split backup roll divided into three or more in an axial direction, and each split backup roll has an independent load detecting device. In a plate rolling mill in which a rolling reduction device is arranged, when zero-point adjustment of the plate rolling mill is performed by tightening a kiss roll, each divided backup roll is individually pushed in advance by using the plate rolling machine, and the pushing amount and the load distribution. By examining the value of the change, a relational expression between the draft reduction amount and the load distribution change amount is created, and the roll assembly is housed so that the divided backup roll load as one reference becomes a desired load. While controlling the load of the inner housing, the load and the rolling position of each divided backup roll at that time were measured and set in advance. The load difference between each split backup roll load is obtained, and from the obtained load difference and the relational expression, the roll-down position correction amount of all backup rolls except the reference split backup roll is calculated, and based on the roll-down position correction amount. Controlling the rolling positions of all the divided backup rolls except for the reference divided backup roll. 3. A mechanism in which at least one of the upper and lower roll assemblies supports a work roll by a split backup roll divided into three or more in an axial direction, and a load detecting device independent of each split backup roll. And the rolling-down device are arranged in the inner housing, and at least one of the upper and lower inner housings of the plate rolling mill is provided with a load between the inner housings on both the work side and the drive side and a distance between the inner housings or a work roll chock. A plate rolling machine provided with a device for adding and / or measuring an inter-load and a distance between an inner housing and a work roll chock. 4. When the zero point adjustment according to claim 1 or 2 is performed by the plate rolling mill according to claim 3, before the kiss roll is tightened, the load between the inner housings and the distance between the inner housings or the distance between the inner housings and the inner housing. With a roll gap secured by a device for adding and / or measuring the load between the work roll chock and the distance between the inner housing and the work roll chock, the load between the inner housing and the distance between the inner housings on both the work side and the drive side or the distance between the inner housings A method for adjusting a zero point of a plate rolling mill, comprising adjusting a rolling position of a main housing so that a load between a housing and a work roll chock and a distance between an inner housing and a work roll chock have desired values.