JP3343009B2 - Backup roll role profile control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a roll profile control method for a backup roll.

[0002]

2. Description of the Related Art In general, when a thick plate is rolled using a four-roll rolling mill in which a pair of upper and lower work rolls are supported by a pair of upper and lower backup rolls, the backup roll is moved from the edge to the center in accordance with an increase in the number of rolls. Wears out and has a concave profile as shown in FIG. When the backup roll has a concave profile, the deflection of the work roll increases, which causes an increase in the sheet crown.

Therefore, conventionally, the mechanical crown of the work roll has been increased in accordance with the concave profile of the backup roll, and the influence of the concave profile of the backup roll on the plate crown has been reduced. And
Since there was a limit in correcting the influence of the concave profile of the backup roll by the mechanical crown of the work roll, the backup roll was replaced when the wear of the backup roll exceeded an allowable value (generally determined by the rolling amount).

[0004]

However, in the above-described method of increasing the mechanical crown of the work roll in accordance with the concave profile of the backup roll which changes as the rolling amount increases, the work is adjusted in accordance with the concave profile. Since it is difficult to set the roll mechanical crown, it has not been possible to sufficiently suppress the deterioration of the sheet crown accuracy. Further, when the wear of the backup roll exceeds an allowable value, it is necessary to replace the backup roll.

[0005] For example, Japanese Unexamined Patent Publication (Kokai) No. 1-306003 discloses a rolling method for increasing the life of a backup roll by appropriately reversing the asymmetry in a quadruple or sixfold rolling mill using an asymmetric roll. It is believed that the application of this technique would prevent the asymmetry of the wear of the backup roll, but did not mention any uniform wear over the entire length of the roll.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method suitable for controlling a wear profile.

[0007]

SUMMARY OF THE INVENTION The present invention provides a thick plate while adjusting the bending of a work roll using a quadruple rolling mill in which a pair of upper and lower work rolls provided with a work roll bender are supported by a pair of upper and lower backup rolls. When rolling, the bending force of the work roll bender, forming, set higher than a normal reference value during tentative rolling , and compared the average bending force and wear profile during the backup roll use period . Based on data
Can, the amount of wear of the central portion of the backup roll and the edge portion
A roll profile control method for a backup roll, wherein the bending force is controlled to be substantially the same, and the wear of the backup roll is smoothed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of one embodiment of the present invention. In this drawing, reference numeral 1 denotes a quadruple rolling mill for rolling a rolled material P, which comprises a pair of upper and lower work rolls 2 and 2 and a pair of upper and lower backup rolls 3 and 3 for backing up the work rolls 2 and 2. . Reference numeral 4 denotes a work roll vendor, which includes a hydraulic cylinder 5 for bending the work rolls 2 and 2, a servo valve 6 for operating the hydraulic cylinder 5, a hydraulic source 7, a work roll vendor control device 8, a DDC 9, and a process computer 10. Be composed.

[0009] Then, a rolling command is output from the process computer 10 to the quadruple rolling mill 1 for each rolled material P to be rolled. A control command is output to the work roll bender controller 8 via the control unit, and each hydraulic cylinder 5 is controlled by the servo valve 6. In general, the minimum pressing force at which no slip occurs between the work rolls 2 and 2 and the backup rolls 3 and 3 under no load is a reference value of the bending force. The work roll bender 4 performs rolling while maintaining the bending force of the work rolls 2 and 2 higher than the above-described reference value during forming and tentering rolling without affecting the plate shape and crown.

[0010] Specifically, the following procedure is used. During the forming and tentering rolling, in the DDC 9, the average value of the bending force sampled at a constant time pitch during the rotation of the work rolls 2, 2 during the use of the backup rolls 3, 3 is transmitted to the process computer 10 by the work roll. It is stored as a setting history of the bending force of the vendor 4. The wear profile of the backup rolls 3 and 3 after use is measured using a roll profile measuring device (not shown) and stored in the process computer 10. The process computer 10 compares the average bending force during use of the backup rolls 3 and 3 with the corresponding wear profile to bend the work roll vendor 4 to obtain a target smooth backup roll wear profile. The optimum set value of the force is determined and output to the DDC 9 as a control command.

For example, as shown in FIG. 2, using a characteristic curve E composed of past data groups D ₁ , D ₂ , D ₃ and D ₄ ,
An average value B _S of the bending force such that the difference in wear between the center and the edge of the backup rolls 3 and 3 becomes zero with respect to the average bending force during use is determined, and this is set as a target bending force. The DDC 9 outputs a control signal to the work roll vendor control device 8 based on the control command. The work roll vendor control device 8 controls each hydraulic cylinder 5 via the servo valve 6 based on the control signal,
The bending force during the forming and tentering rolling is controlled so that the average value of the bending force during use is always the target. At the stage of finish rolling, the work roll bender 4 performs a normal strip crown control.

[0012]

[Example] During forming and tentering rolling, the set value of the average bending force was set to a reference value of 225 ton / chock, and the bending force during the use period of the backup roll was generally reduced.
Rolling was controlled to increase by 50 tons / chock. As a result, the wear profile after the use of the backup rolls 3 and 3 was as shown in FIG. In order to facilitate comparison, FIG. 3 shows a conventional wear profile (the same as that shown in FIG. 4) by a broken line.

As can be seen from this figure, the wear profile of the example of the present invention is almost the same as that of the conventional example in the amount of wear at the central portion and the edge portion, so that a uniform wear profile is obtained.

[0014]

As described above, according to the present invention,
Since the work roll bender controls the wear profile of the backup roll during forming and tentering rolling, it is not necessary to adjust the mechanical crown of the work roll by using the backup roll. Since the deterioration of the wear profile of the backup roll can be prevented, the replacement cycle of the backup roll can be greatly extended. It has excellent effects such as.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between an average bending force and a wear difference during a use period of a backup roll.

FIG. 3 is a characteristic diagram showing a wear profile of a backup roll when the present invention is applied.

FIG. 4 is a characteristic diagram showing a wear profile of a conventional backup roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Quadruple rolling mill 2 Work roll 3 Backup roll 4 Work roll bender 5 Hydraulic cylinder 6 Servo valve 7 Hydraulic power source 8 Work roll bender control device 9 DDC 10 Process computer P Rolled material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification symbol FI B21B 37/00 BBJ B21B 37/00 BBJ (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 13/14 B21B 27 / 02-29/00 B21B 37/00-37/78

Claims (1)

(57) [Claims] When a thick plate is rolled while adjusting the bending of a work roll using a quadruple rolling mill that supports a pair of upper and lower work rolls provided with a work roll bender with a pair of upper and lower backup rolls. Set the bending force of the roll bender higher than the normal reference value during forming and tentering rolling ,
And based on the data by comparing the wear profile and the average bending force during the backup roll period of use, back
The wear amount of the central part and the edge part of the cup roll is almost the same
A method of controlling a roll profile of a backup roll, wherein the bending force is controlled so as to smooth the wear of the backup roll.