JPS58218302A - Method and device for roll cross rolling - Google Patents

Abstract

PURPOSE:To control snaking effectively by providing four pieces of roll cells between an upper backup roll chock and the upper part of a housing and between a lower backup roll chock and the lower part of the housing on the work side and the driving side. CONSTITUTION:A rolled material S is rolled down with work rolls 3, 4. The load to be applied on backup rolls 1, 2 with screws is detected with vertical and lateral load detectors 8, 8', 9, 9' and are fed to a calculator, by which the differential rate of load is determined. The result of the calculation is inputted to a proportional calculator 11 and a differential calculator 12. The proportional action signal and differential action signal from these calculators are added in an adder 13. The signal from the adder 13 is fed through a rolling position controller 14 to lateral rolling position setters 7, 7', by which the roll gap on the right and left is adjusted according to the rate of snaking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for rolling a plate material using a four-cross method.

In recent years, requirements for thickness accuracy in the width direction of rolled products have become increasingly strict, and currently this is being addressed by attaching an initial crown to the roll in order to cancel the deflection of the roll due to the rolling load. but,
When the rolling conditions such as the width and thickness of the plate material change, it is necessary to replace the roll with a roll with a different crown, so it is necessary to have rolls with many different types of initial crowns. Replacing the rolls causes a drop in the operating rate of the rolling mill, and as the rolling process progresses, the crown of the 6-hole changes significantly due to 50-degree wear and thermal expansion, so it is conventionally not necessary to replace the rolls. There has been a need in the industry for a means to control the thickness distribution in the width direction of a plate material without the need for a thickness distribution.

As a method for controlling this, a method of bending work rolls (work rolls) has been developed as is well known, and has achieved some degree of effectiveness, but this method has a limit to the strength of the roll neck of the work roll and the pending force that can be applied to the work roll Because of this, it was not possible to obtain sufficient thickness distribution correction ability in the sheet width direction. , 1 On the other hand, by rolling the axis of the rolls so that they slightly intersect within the Crk horizontal plane, the sheet width direction: Haze:.

Modify the thickness distribution of. The so-called °'' roll cross rolling technique is well known.
No. 75456 has an upper reinforcing roll, 2 as shown in Figure 1.
A technique for rolling a plate by intersecting the axes of the upper and lower work rolls 3.4 in the horizontal plane, and a technique for rolling the plate by intersecting the axes of the upper and lower work rolls 3.4 in the horizontal plane, as shown in FIG. ing. , and in Japanese Patent Application Laid-Open No. 55-64908, No. 3
As shown in Figures (a) and (b), the upper work roll 3 and the upper reinforcing roll 1 and the lower work roll 4 and the lower reinforcing roll 2 are kept in a state in which their axes are kept substantially parallel to each other, and the upper pair roll and the lower pair roll, respectively. A technique is disclosed in which the axes of the upper and lower pair of rolls intersect in a horizontal plane to roll a plate material. Furthermore, Japanese Patent Publication No. 50-24903 discloses a technique for rolling a plate material by intersecting the axes of the upper and lower intermediate rolls 5.6 in a horizontal plane, as shown in FIG. In such roll cross rolling, the original aim is to catch the deflection of the rolls.
：1. ', 1. ．． -F is somewhat effective, but generally attempts to move the roll in the axial direction. It has been known for a long time that so-called thrust force is generated. This thrust force can be counteracted by increasing the strength of the mechanical parts that hold the rolls, but
The inventors of the present invention have discovered that there is a drawback that the load on the working side and the load on the driving side detected by the rolling load detector are different due to this thrust force. In other words, the example is number 3.
This is true when the axes of the upper and lower pair of rolls shown in the figure intersect in a horizontal plane.

A thrust force as shown in No. 5a acts, and from the balance of force and moment, a reduction force imbalance as shown in the following equation (1) occurs, “Δp=p・□
----------, (1) Also, in the case of crossing only the reinforcing rolls shown in Figure 1 or crossing only the work rolls, a thrust force as shown in Figure 6 is applied. As a result of the study, it has become clear that a reduction force/lance as shown in the following equation (2) is generated from the balance of force and moment.

When such an unbalance of rolling force between the left and right sides occurs, it becomes difficult to control meandering in order to roll the plate material straight. This meandering control is described in, for example, Japanese Patent Publication No. 55-88914.
In a normal 4-high rolling mill, rolling may occur if the passing position of the rolled plate deviates to the left or right (work side or drive side) with respect to the roll center, or if it is skewed to the pass center line. In order to prevent the meandering that would occur if the work is carried out, the load x' is detected by two load detectors installed between the reinforcing roll chocks on the working side and the driving side and the housing.

A method is disclosed in which the left and right roll openings are fully automatically adjusted based on the load difference (rolling force unbalance) signal and the like.

However, in cross-roll rolling, even if rolling is performed under normal conditions, as explained earlier in Figures 5 and 6, a left and right rolling movement lance occurs, so meandering control is effective. The problem is that it does not work.
□ To solve this problem, the inventors of the present invention have discovered that by installing four rolling 4dr 'ii detectors and calculating the sum of the upper and lower load detection signals, the left and right rolling displacement can be eliminated. The gist of this is that the work side and drive side of a 5-hole Le Cross rolling mill.

By providing a total of 4 rolling load detectors between the upper reinforcing roll chock and the upper part of the housing and between the lower reinforcing roll chock and the lower part of the housing, the output signal from the detectors is used to adjust the left and right rolling force. rolling method for meandering control (based on the output signal from the detector)
The present invention provides a rolling method for detecting thrust force generated in the axial direction of a roll and using it as an emergency measure signal for a rolling mill, and an apparatus for carrying out the method.

The present invention will be explained in more detail below with reference to the drawings.

In this invention, as shown in FIG. 7, a load cell 22 is placed on the upper side of the rolling mill, that is, between the upper reinforcing roll chock 21 and the upper part of the housing (not shown). A hydraulic cylinder 23 and a load cell 22' are arranged between the lock 21' and the lower part of the housing (not shown),
Each load cell detects the load separately. Its load t-PwT (working side on C).

PDT (Upper driving side) IPWB (Lower working side) y
PDB (lower drive side), material S in Figure 5
On the other hand, in the upper roll group, the following equation (3) holds true from the balance of moments around point A.

(-PDT-PWT)'"F" two w two.
−−2 D ′,”−PDT −1’w’r = F・□ −−−1−
--(3) Furthermore, in the lower roll group with respect to the material S, the following equation (4) holds true from the balance of the Monimen group around the circumference of point B.

a D (PWB PDB)' ”F@1-,・
) 2 I1 W −'−PWB PDdan=p @, −−−−1−(
4) Therefore, from the above (,゛)2 formula and (42 formula), we obtain the following (5)5.8ゎ,J,,・(・
・1', 1'w'r IPWB =""VDT+Priu" -
-----:'<5) Db Db (5) If only the upper load cell or the lower hydraulic cylinder is used for measurement, there will be a difference in the left and right loads, but if you take the sum of the upper and lower loads, the thrust force will be This means that the influence of is removed, and the load on the working side and the load on the driving side become equal.

The meandering amount and load difference (
As shown in Fig. 8, the meandering amount is calculated as follows: Yet, the load on the working side, k, Pwy, the load on the drive side, tPpy, the difference between both loads, t" d f=FW" D
When the rolling load, which is the sum of both loads, is pm==p7+pD, the following equation (6) holds true from the balance of force and moment.

Pdf""Pm@Yc' -
'-(6) Therefore, in roll cross rolling, PV
If VyPD is subjected to arithmetic processing as shown in equation (7) below, equation (6) will hold as is.

In this way, all the signals from the four load detectors (7)
Using the calculation process as shown in the formula, the left and right
If the roll opening degree of m is automatically adjusted, meandering control will work effectively even in roll cross rolling.

Here, an example in which actual meandering is automatically controlled based on the load difference rate rdf will be described using FIG. 8 as an example.

The rolled material S is rolled down by work rolls 3.4, and work rolls 3 and 4Fi each roll 1°2 of Nonotsuquazzo roll.
Supported by 2. Apply Nonotsukuazool l via a reduction screw (not shown). The load applied to the upper, lower and left and right load detectors 8°8', 9.9
Detected by '. Detected load signal PWB?
PWT e PDB t PDT is sent to the arithmetic unit to6
Re.

is required.

The results of this calculation are input to a proportional calculator 11 and a differential calculator 12, and the proportional operation signal and the differential operation signal from these calculators are added together by a charger 13. The signal 8df from the adder 13 is sent to the left and right roll position setters 6.7 via the roll down position controller 14, and the left and right roll openings are adjusted in accordance with the meandering tyc. For example, when the rolled material shifts toward the operation side, the roll opening on the operation side is decreased in accordance with the load difference rate rdf and its rate of change over time, and at the same time, the roll opening on the drive side is increased by the same amount. The gains of the proportional calculator and the differential calculator are configured so that they can be changed according to the rolling conditions, and in this embodiment, they are configured to be automatically set to values calculated by a calculator (not shown). However, in this example, the relationship in the control system for the average plate thickness has been omitted. However, the average plate thickness is controlled by controlling the openings of both side rolls by the same amount in the same direction. In contrast, meandering control controls the same amount in the opposite direction.In reality, both sheet thickness control and meandering control may be performed at the same time, but in this case, each roll opening on the operation side and drive side is It is sufficient to input the degree as the sum of both control signals to the lowering position setters 6 and 7 for control.

Proportional calculation is to fully adjust the opening of the left and right rolls in proportion to the meandering, and is a basic calculation that can also be seen in other controls such as foot-to-noise control of plate thickness. The reason for performing the differential calculation is that when the control to correct meandering is adjusting the opening of the left and right four wheels, simply controlling proportional to the amount of meandering is insufficient. Although this has been revealed through research and has been separately patented, it has no essential relationship with the present invention, so its explanation will be omitted.

By the way, it is known that in roll cross rolling, a large thrust force is generated in the axial direction of the rolls21'.

It is being This δ lastka is not shown in the figure, but 1. First of all, rollcho? , '111:1. The thrust force is applied to the thrust bearing built into the second housing post, and is finally received by the housing post. However, if the thrust force becomes excessive due to pressure treatment conditions and exceeds the thrust force allowed by the thrust bearing, the thrust bearing will burn out. Accidents may occur.

Thrust force is normally detected by a load cell for thrust force measurement, and as an emergency measure in rolling operations, when the thrust force exceeds a certain value, the operator manually opens the glt between the rolls to reduce the thrust force. It is used as a judgment criterion or as a signal for controlling the roll gap to be automatically opened when the thrust force exceeds a certain value. However, this type of measuring instrument sometimes fails. For this reason, it is desirable to have a device that can detect double or triple thrust force.

If a total of four load cells are installed above and below the work side and drive side, the following equation (10) can be obtained from the above equations (3) and (4). - It is shown that the thrust force can be detected by calculating the output signal of the docel.

Then, the thrust force detected by the thrust force measurement load cell is used as the output signal for the emergency pair.

The output signals of the four load cells are compared with the thrust force calculated using the formula (10) above, and the larger thrust force is taken as the true thrust force, and when the value exceeds a certain value. , safety can be improved by performing the operations described above.

In this way, by providing a total of four load cells between the upper reinforcing roll chock and the upper part of the housing and between the lower reinforcing roll chock and the lower part of the housing on the work side and drive side, meandering control can be effectively performed. As a result, the desired thickness distribution in the plate thickness direction can be obtained, thrust force can be detected, rolling mill failure can be prevented, and safety can be improved.

[Brief explanation of the drawing]

FIGS. 1 to 4 are explanatory diagrams of the conventionally known roll cross rolling method, FIGS. 5 and 6 are explanatory diagrams of the occurrence of rolling reduction lances, and FIGS. 7 and 8 are explanatory diagrams of the present invention. be. 1.2-・Reinforcement roll, 3,4...Work roll, S・
・Rolled material, 5, 6... Intermediate roll, a... Distance between reinforcement roll support points, P... Rolling load, ΔP... Load difference (rolling resistance) m DW"・Work roll diameter b DB"...Reinforcement 0-1 diameter, F...Thrust force between material and roll, F'...Thrust force between rolls% p
w'r...Load on the upper working side, PDT...Load on the upper driving side Th PWB-...Load on the lower working side, PDB...-
Load on lower drive side, b...Plate width b 7C...Off center amount, 7, 7'--Down position setter, 8.8', 9
゜9'...Load detector% 10...Arithmetic unit, 11.
... Proportional calculator, 12... Differential calculator, 13-, -.
Adder, 14... Lowering position controller, :1, , :',. Agent Patent attorney Aki □ I, Masaru Sawa Two people outside the party crying Figure 2 Figure 71'3 (α) 1) (b) 17t'4I\] (Q) (b) Figure 6 fF7FiJ Figure Oδ

Claims (3)

[Claims] (1) When rolling a plate material using a P-Lecross rolling machine that performs rolling by intersecting the roll axes at an arbitrary angle in a plane parallel to the advancing surface of the rolled material. The left and right rolling reduction is adjusted according to the output signals from four rolling load detectors installed between the upper reinforcing cylinder-le chock and the upper part of the housing on the work side and drive side, and between the lower reinforcing roll chock and the lower part of the housing. A roll cross rolling method characterized by fully controlling the meandering of the sheet material. (2) When rolling a plate material using a roll cross rolling mill that performs rolling by intersecting the roll axes at an arbitrary angle in a plane parallel to the advancing surface of the rolled material. The thrust force generated in the axial direction of the roll is detected by output signals from four rolling load detectors installed between the upper reinforcing roll chock and the lower housing on the work side and drive side, and between the lower reinforcing roll chock and the lower housing. A roll cross rolling method characterized in that the detection is used as an emergency measure signal for a rolling mill. (3) In a plane parallel to the advancing plane of the rolled shaft bar material,
In a roll cross rolling mill that performs rolling by crossing each other at an arbitrary angle, a total of four rolling load detection devices are installed between the upper reinforcing roll chock on the work side and drive side and the upper part of the housing, and between the lower reinforcing roll chock and the lower part of the housing. A roll cross rolling device characterized by having a container.