JPH0586289B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plate rolling mill, and in particular prevents the upper and lower work rolls of the rolling mill from being arranged asymmetrically with respect to the rolled material, and always maintains symmetry. The present invention relates to a method and apparatus for controlling the offset position of work rolls in a rolling mill, which enables maintained rolling.

[Conventional technology]

In recent years, there has been a remarkable tendency to reduce the diameter of work rolls in cold plate rolling mills, and the rolling mill structure for this purpose is described in the literature (Hitachi Hyoron, April 1985 issue, p. 19).
The "High Precision Shape Control Rolling Mill ``UC-MILL'''' shows a six-high rolling mill with a structure that includes support rolls that horizontally support work rolls that are supported by intermediate rolls that move in the axial direction. There is. In other words, the axes of the upper and lower work rolls are offset from the axis of the intermediate roll in the forward and backward direction of the pass direction, and supported by two upper and lower support rolls that are sequentially arranged in the horizontal direction from the offset side. It is something. The positions of the upper and lower support rolls in the longitudinal direction can be adjusted individually, thereby determining the amount of offset of the work roll in the longitudinal direction.

[Problem that the invention seeks to solve]

When setting the offset amount of the upper and lower work rolls,
The straight line connecting the centers of the upper and lower rolls must be perpendicular to the line of the rolled material, that is, the upper and lower rolls must be set symmetrically. If for some reason there is a back-and-forth shift in the positions of the upper and lower work rolls, the rolled material will warp and the product yield will deteriorate. The same is true when looking at the rolling mill from above; if the work roll axis is not placed at right angles to the rolled material,
This causes the board to meander, leading to so-called squeezing and board breakage, which reduces productivity. In conventional devices, no consideration has been given to correcting the asymmetry of these vertical work roll offset positions, and there has been a problem in that the above-mentioned troubles may occur frequently.

An object of the present invention is to provide a method for controlling the work roll offset position of a rolling mill and a control device therefor, which corrects the asymmetry of the upper and lower work roll offset positions and enables stable rolling without the above-mentioned troubles. It is in.

[Means for solving problems]

In order to achieve the above object, the present invention provides a work roll offset position control method for a rolling mill having at least one pair of work rolls, in which a horizontal force applied to each of the pair of work rolls is detected, and a horizontal force applied to each of the pair of work rolls is detected. A device that adjusts the longitudinal position of at least one of the pair of work rolls so that the forces are equal, or a horizontal force that is applied to the driving side and the operation side of at least one of the pair of work rolls. is detected, and the longitudinal position of at least one of the driving side and the operating side is adjusted so that the horizontal forces are equalized.

Further, in a work roll offset position control device for a rolling mill having at least one pair of work rolls, there is provided a detection means for respectively detecting a horizontal force applied to the pair of work rolls, and a detection means for detecting a horizontal direction force applied to the pair of work rolls, and a detection means for detecting a horizontal direction force applied to the pair of work rolls. roll position moving means for setting each of the work rolls, and a control means for driving and controlling at least one of the roll position moving means for the pair of work rolls based on the detection value of the detection means; detection means for detecting horizontal forces applied to the drive side and operation side of at least one of the work rolls; and roll position movement for setting the longitudinal positions of the drive side and operation side of the pair of work rolls, respectively. and a control means for driving and controlling at least one of the roll position moving means on the drive side and the operation side of the work roll based on the detected value of the detection means.

[Effect]

In the present invention, the longitudinal position of at least one of the upper and lower work rolls is adjusted so that the longitudinal support reaction force applied to the upper and lower support rolls, that is, the horizontal force applied to the work roll is the same on the upper and lower sides. That's what I do. The same applies to the asymmetry in the left-right direction, and the longitudinal position of at least one of the work rolls on the drive side or the operation side is adjusted so that the force has the same value on the drive side and the operation side.

The effects of the above configuration are as follows.

First, FIG. 2 shows how the support roll support reaction force is generated when the upper and lower work rolls are displaced in the front-rear direction. Here, it is assumed that the intermediate rolls 3 and 4 that support the work rolls 1 and 2 in the vertical direction are vertically symmetrically arranged. It is also assumed that the centers of the support rolls 7 and 8 that support the work rolls in the front-rear direction and the centers of the work rolls 1 and 2 are both in the same horizontal plane. In Figure 2, support roll support reaction force F ₁ (upper roll), F ₂ (lower roll) due to rolling load P
becomes as follows.

F ₁ = P(tanθ ₁ + tanθ ₀ )・cosθ ₀ …(1) F ₂ =P(tanθ ₂ − tanθ ₀ )・cosθ ₀ …(2) In equations (1) and (2), θ ₀ is Upper and lower work rolls 1 and 2
θ ₁ is the angle between the straight line connecting the centers of the upper work roll 1 and the upper intermediate roll 3 and the vertical line, θ ₂ is the center of the lower work roll 2 and the lower intermediate roll 4 is the angle that the straight line connecting them makes with the vertical line. On the other hand, since the straight line connecting the centers of the upper and lower intermediate rolls is vertical, the following equation holds.

sinθ ₁ = (R _W · sinθ ₀ + y) / (R _W + R _z ) ...(3) sinθ ₂ = (−R _W · sinθ ₀ + y) / (R _W + R _z ) ... (4) Here, R _w is the work roll radius, R _I is the intermediate roll radius, and y is the standard work roll offset amount. From equations (1) and (2), the difference ΔF between the upper and lower support reaction forces is as follows: ΔF=F ₁ −F ₂ =P(tanθ ₁ −tanθ ₂ )・cosθ ₀ ...(5) θ ₁ and θ ₂ are Since it is small, tanθ≒sinθ, and equation (5) can be rewritten as follows.

ΔF≒P(sinθ ₁ −sinθ ₂ )・cosθ ₀ …(6) Comparing equations (3) and (4) with equation (6), ΔF≒2R _W /R _W +R _I・P・cosθ ₀・sinθ ₀ ...(7) Since θ ₀ is also small, cosθ ₀ ≒1, so ΔF≒2R _W /R _W +R _I・P・sin θ ₀ ……(8). From equation (8), in order for ΔF to become 0, θ ₀
It turns out that must also be 0. As can be seen from FIG. 2, the fact that θ ₀ is 0 means that the upper and lower work rolls are arranged vertically symmetrically. That is, by moving the upper work roll, which has a large reaction force, to the right in Fig. 2, θ ₀ in equation (8)
becomes smaller, ΔF approaches 0, and the asymmetry is corrected.

The case of left-right asymmetry is also exactly the same as above.

〔Example〕

FIG. 1 shows a working roll offset position control device for a rolling mill, which is an embodiment of the present invention. The jocks 11 and 12 of the support rolls 9 and 10 are provided with load cells 13 and 14 for detecting support reaction forces F ₁ and F ₂ , and the longitudinal position adjustment screws 15 and 16 and their control devices 17 and 18 are installed. is set up. These position control devices are attached to a housing (not shown) and have a structure that receives support reaction force. Load cell 13 has F ₁ , load cell 14 has F ₂
is detected and sent to the computer 19, where the difference ΔF is calculated. The calculator 20 calculates the upper work roll movement amount Δy ₁ and the lower work roll movement amount Δy ₂ using the following formula. First, the sine of the angle θ ₀ between the vertical line and the straight line connecting the centers of the upper and lower work rolls 1 and 2 is determined using the following equation, which is a modification of equation (8).

sinθ ₀ = R _W + R _I /2R _W・ΔF/P …(9) Next, Δy ₁ and Δy ₂ are Δy ₁ = R _W・sinθ ₀ = R _W +R _I /2・ΔF/P …(10 ) Δy ₂ = −R _W・sinθ ₀ ...(11).

The load P required to calculate equations (10) and (11) is the load cell 2
1, and the work roll radius R _W and intermediate roll radius R _I are set from the setting board 22 .

The calculated Δy ₁ and Δy ₂ are sent to the longitudinal roll position control devices 17 and 18, and the longitudinal positions of the work rolls 1 and 2 are controlled.

FIG. 3 shows an embodiment showing a correction method when the left and right sides are asymmetrical. The drive side load cell 25 detects the support reaction force F ₃ , and the calculator 19 calculates the difference ΔF _H from the operation side support reaction force F ₁ . The position control device may be adjusted so that ΔF _H becomes 0. Letting the adjustment amount for this be Δy _H , the calculator 28 calculates Δy _H = d・ΔF _H , and the calculator 29 divides this equally into Δy ₁ = Δy _H /2 Δy ₂ = −Δy _H /2 Then, it may be outputted to the respective position control devices 17 and 27. Here, α is a control gain, which is a constant determined to an extent that hunting does not occur. Naturally, when correcting the vertical asymmetry shown in FIG. 1, it is also possible to use the simplified method shown in FIG. 3.

Next, a method of combining the vertical asymmetry correction method shown in FIG. 1 and the horizontal asymmetry correction method shown in FIG. 3 will be described. Although both FIG. 1 and FIG. 3 show the rolling material 23 being rolled, this is generally carried out during zero adjustment before rolling. The rolling mill is squeezed under a certain load, and the asymmetry on the upper side of the rolling mill is first corrected. Next, the left-right asymmetry on the lower side is corrected in the same way, but at this time, it is checked whether the left-right symmetry on the upper side has collapsed. If it is distorted, fix the upper part again. After further modifying the upper part,
If the symmetry of the lower side is broken, correct the lower side. At this time, if you try to correct the left and right support reaction force difference ΔF _H until it becomes completely zero, you will have to repeat the correction quite a number of times at the top and bottom. Therefore, if the correction is stopped when ΔF _H falls below a certain small value, symmetry can be achieved in a short time. After obtaining horizontal and vertical symmetry, the vertical symmetry is then corrected. At this time, the supporting reaction force used in the explanation of Figure 1
As F ₁ and F ₂ , the sum of the left and right supporting reaction forces is used. Of course, it goes without saying that the position correction in the front and back direction is also performed simultaneously on the left and right sides.

The above method is just an example, and there are various other combinations. That is, the vertical asymmetry may be corrected first, and then the horizontal asymmetry may be corrected. In the case of correcting left-right asymmetry, as described above, the correction is performed alternately on the upper side and the lower side of the rolling mill, and is repeated until symmetry is obtained on both the upper and lower sides. Alternatively, the vertical asymmetry correction may be performed independently on the left and right sides, that is, the operating side and the driving side, and then the horizontal symmetry may be corrected.

As for feedback control during rolling, all of the above-mentioned modification methods can of course be used. However, if the left-right asymmetry is corrected during rolling, it may conversely induce meandering of the rolled material. For this reason, the horizontal asymmetry may be corrected before rolling, and only the correction loop for the vertical asymmetry is activated during rolling.

In the explanation so far, a 6-high rolling mill was used as an example, but
It goes without saying that the same thing can be done with other four-high rolling mills. Furthermore, even if there is no support roll, the present invention can of course be applied as long as the structure is such that the horizontal reaction force can be directly detected by the chock of the work roll and the longitudinal position of the chock can be adjusted.

〔Effect of the invention〕

According to the present invention, the work rolls can be easily arranged symmetrically in both the vertical and horizontal directions with respect to the rolled material, and various troubles associated with asymmetry in arrangement, such as board warping and meandering, can be prevented, and the work rolls are extremely stable. This makes it possible to operate in a manner that is highly effective in improving product yield and productivity.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a work roll offset position control device for a rolling mill which is an embodiment of the present invention for correcting vertical asymmetry, Fig. 2 is a diagram illustrating the principle of the invention, and Fig. 3 is a diagram illustrating the principle of the present invention. FIG. 2 is a schematic configuration diagram of a work roll offset position control device for a rolling mill, which is another embodiment of the present invention for correcting left-right asymmetry. 1, 2... Work roll, 3, 4... Intermediate roll, 5, 6... Reinforcement roll, 7, 8... First support roll, 9, 10... Second support roll,
11, 12, 24...Support roll check,
13, 14, 25...Load cell, 15, 16,
26...Anteroposterior position control screw, 17, 18,
27...Position control device, 19, 20, 28, 29
...Calculator, 21...Load cell, 22...Setting board, 23...Rolled material.

Claims (1)

[Claims] 1. A work roll offset position control method for a rolling mill having at least one pair of work rolls, comprising: detecting a horizontal force applied to each of the pair of work rolls, and making the horizontal forces equal. A work roll offset position control method for a rolling mill, comprising adjusting the longitudinal position of at least one of the pair of work rolls. 2. A work roll offset position control method for a rolling mill having at least one pair of work rolls, which includes: detecting a horizontal force applied to the drive side and the operation side of at least one of the pair of work rolls; A work roll offset position control method for a rolling mill, comprising adjusting the longitudinal position of at least one of the driving side and the operating side so that the forces in the directions are equal. 3. A work roll offset position control device for a rolling mill having at least one pair of work rolls, comprising detection means for respectively detecting horizontal forces applied to the pair of work rolls, and detecting means for respectively detecting horizontal forces applied to the pair of work rolls; A work roll for a rolling mill, comprising a roll position moving means for setting the position, and a control means for driving and controlling at least one of the roll position moving means of the pair of work rolls based on a detection value of the detection means. Offset position control device. 4. In a work roll offset position control device for a rolling mill having at least a pair of work rolls, a detection means for detecting horizontal forces applied to the drive side and the operation side of at least one of the pair of work rolls, respectively. and roll position moving means for setting the forward and backward positions of the drive side and the operation side of the pair of work rolls, respectively, and the roll position movement means for the drive side and operation side of the work rolls based on the detected values of the detection means. 1. A work roll offset position control device for a rolling mill, comprising a control means for driving and controlling at least one of them.