JP2899773B2 - Roll cross angle change device during running - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of measuring a roll cross angle and a roll movement amount, or a roll cross angle, a roll movement amount and a roll bending force in a rolling mill provided with a roll shift type shape changing device, during rolling operation. The present invention relates to an inter-running roll cross angle changing device that changes according to dimensions of a coil.

[0002]

2. Description of the Related Art A roll cross type rolling mill in which the roll axes of an upper work roll and an upper backup roll and a lower work roll and a lower backup roll are non-parallel to each other, that is, cross at an appropriate angle. A plate shape control device for correcting a shape such as a crown or flatness is known (Japanese Patent Publication No. 63-35325). As such a roll cross type rolling mill, a rolling mill having a structure provided with a work roll shift device for relatively moving upper and lower work rolls at a predetermined speed in the axial direction is known (Japanese Patent Application Laid-Open No. Sho 57-57). (206503)
.

In such a conventional apparatus, prior to the start of rolling, dimensional specifications such as the material of the coil to be rolled, the sheet width, the sheet thickness, etc., the target value of the inlet side sheet crown, the output side sheet crown, the rolling load, the flatness target The optimum roll cross angle based on data such as values, and in the case of a roll cross type rolling mill equipped with a work roll shift device, in addition to this, the relative movement amount of the upper and lower work rolls, or the roll of the roll bender Calculate and set the bend force.
The actual values such as the output flatness and the edge drop amount are obtained, and the roll cross angle is corrected and controlled so as to maintain the actual values within the allowable range of the target value.

In the conventional apparatus as described above, there is no inconvenience when a single type of manufactured coil is manufactured from a single type of base material coil. In the case of continuously rolling many types of coils by welding the top of the same, or in the case of obtaining coils of different thicknesses by changing the running strip thickness in the middle of one base material coil, Since the succeeding coil is rolled continuously to the coil, the initial setting of the optimum roll cross angle for the preceding coil can be performed before the start of rolling, but the initial setting cannot be performed for the following coil. In the case of continuous rolling, there is a problem that the conventional method of rolling only a normal single coil cannot be applied as it is.

As a countermeasure, the present inventors set the roll cross angle in accordance with the timing at which the connecting portion of both coils passes through the rolling mill in the process of continuously rolling the preceding coil and the succeeding coil connected thereto. A means for indicating a change timing, and a roll cross angle during running that enables the roll cross angle to be changed according to the dimensions of each of a plurality of types of coils to be rolled which are continuously fed during the rolling operation. A change device has already been proposed (Japanese Patent Application No. 2-296767).

[0006]

In the conventional apparatus as described above, since the roll cross angle setting is in a transition state from the start of the roll cross angle setting change to the end of the setting change, an appropriate plate crown is set. Although the flatness cannot be obtained, it takes a certain amount of time to change the roll cross angle. Therefore, even when the rolling speed is changed and the standard rolling speed is
There is a problem that a shape defect portion of up to 30 m is generated, which greatly affects the product yield.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and reduces the occurrence of a shape defect portion occurring during a setting transition period from the start to the end of a change in the roll cross angle.
It is an object of the present invention to provide a running roll cross angle changing device capable of improving the yield.

[0008]

According to a first aspect of the present invention, there is provided a running roll cross angle changing device including: means for relatively moving an opposing roll in an axial direction; and means for applying a roll bending force to the roll. In the process of continuously rolling the coil in a cross-roll type rolling mill, a running roll cross angle changing device that changes the roll cross angle together with the roll relative movement amount and the roll bending force is used to change rolling conditions. Means for instructing the setting change timing of the roll cross angle according to the timing; means for changing the set value of the roll cross angle based on the instruction of the means; setting of the roll relative movement amount in accordance with the timing of the rolling condition change Means for instructing the change timing; means for changing the set value of the roll relative movement amount based on the instruction of the means; Characterized by comprising means for instructing the setting change timing of roll bend force, and means for changing the set value of the roll bending force based on the instruction of the means.

A running roll cross angle changing device according to a second aspect of the present invention is the running cross roll angle changing device according to the first aspect, wherein a set roll cross angle with respect to a preceding coil and a following Means for calculating a difference between a set roll cross angle with respect to a coil, means for determining a difference between a set roll relative movement amount with respect to a preceding coil and a set roll relative movement amount with respect to a succeeding coil prior to a timing of changing rolling conditions; Means for obtaining a change pattern of the roll bending force prior to the timing of the condition change.

[0010]

According to the first aspect of the invention, the roll cross angle, the roll relative movement amount, and the roll bending force are changed in accordance with the timing of changing the rolling conditions. The shortage of the control amount of the coil shape control by the relatively slow roll cross angle control and the work roll shift amount control is compensated by the coil shape control by the work roll bend force, which has a relatively fast response.

In the second invention, when the control according to the first invention is performed, prior to the timing of changing the rolling conditions, the change amount of the roll cross angle, the change amount of the roll relative movement amount, and the roll bending force are changed. The change patterns of the roll cross angle, the roll relative movement amount, and the roll bend force are changed based on the results, so that the roll cross angle, the roll relative movement amount, and the roll bend The force is changed while performing control utilizing the respective control characteristics.

[0012]

[Principle] The main control elements for the sheet crown and flatness of a roll cross type rolling mill using a work roll shift device are the roll cross angle, the work roll shift amount, and the work roll bend force. For example, a relational expression as shown in the following expression is obtained for each coil in accordance with the dimensions of the coil so that a suitable plate shape can be obtained.

A ₀ + a ₁ θ ² + a ₂ δ + a ₃ F = 0 θ: roll cross angle δ: work roll shift amount F: work roll bending force a ₀ , a ₁ , a ₂ , a ₃ : parameters determined for each coil

The roll cross angle, the work roll shift amount, and the work roll bend force are equivalent from the viewpoint of the effect on the plate shape. However, when viewed as an actuator, the roll cross angle can be controlled. The work roll shift amount is wide by using a work roll with a tapered curve at the end.
Although both have the effect of reducing the edge drop, both have the characteristic that the response is slow, and the work roll bend force has the characteristic that the response is fast but the range of the plate shape that can be controlled is narrow.

Focusing on this point, a good plate shape can be obtained by utilizing the advantages of the two actuators of the roll cross angle and the work roll shift amount, and supplementing the disadvantage of slow response by the work roll bending force. It is possible to reduce the change in the roll cross angle and the occurrence of shape defects during the transition period.

FIG. 1 is a view for explaining the principle of the apparatus of the present invention. FIG. 1A is a graph showing the relationship between the roll cross angle and the work roll bending force when the work roll shift amount is constant. b) shows a connection between the narrow leading coil A and the wide trailing coil B. The graph of FIG. 1 (a) shows the roll cross angle (θ) on the horizontal axis and the work roll bending force (F) on the vertical axis, where R _A1 and R _A2 are the work roll shift amounts, respectively. Are the optimum curves showing the relationship between the roll cross angle and the work roll bend force with respect to the preceding coil A when δ ₁ and δ ₂ , and R _B1 and R _B2 are the following curves when the work roll shift amounts are δ ₁ and δ ₂ , respectively. 4 shows an optimum curve showing a relationship between a roll cross angle and a work roll bend force with respect to a coil B.

Therefore, in the preceding coil A, when the work roll shift amounts are δ ₁ and δ ₂ , the optimum curves R _A1 and R _{A2 are respectively obtained.}
In addition, in the succeeding coil B, when the work roll shift amount is δ ₁ , δ ₂ , optimal rolling is performed by maintaining the relationship represented by the optimum curves R _B1 , R _B2 , respectively. A plate shape is obtained.

From the viewpoint of reducing the edge drop, the work roll shift amount is preferably such that the tapered portion is located at an appropriate position with respect to the plate width of the coil. Similarly, in order to secure an appropriate range of the work roll bend force as the control range, it is desirable to maintain the work roll bend force at 1/2 of the maximum bend force _Fmax .

Therefore, the optimum work roll shift amount with respect to the preceding coil A is δ ₁ , and the work roll bending force is F _max /
Assuming that the optimum roll cross angle at θ2 is θ _A , the optimum work roll shift amount with respect to the succeeding coil B is δ ₂ , and the optimum roll cross angle at work roll bend force of F _max / 2 is θ _B , At the connection between the coil A and the following coil B, the work roll shift amount is changed from δ ₁ to δ
_2, but the changing the roll cross angle from theta _A to theta _B, this time. The roll cross angle, the work roll shift amount, and the work roll bend force are changed as follows so that the time for deviating from the optimum shape is minimized.

Here, the roll cross angle representing the optimum shape,
The relationship between the work roll shift amount and the work roll bend force should be discussed three-dimensionally.
Assuming that the work roll monotonously shifts at a constant speed,
It is discussed as a dual relationship between roll cross angle and work roll bend force.

[0021] That is, the prior coils A tail portion A ₁ of the roll cross angle and the work roll shift from rolling time change starts against the, and ends the change in the rolling time for the top portion B ₁ of the trailing coil B . At this time, assuming that the work roll shift amount changes linearly from δ ₁ to δ _{2, the} optimum curve for the preceding coil A is R _A ′.
In expressed, the optimal curve for the succeeding coil B is represented by R _B '.

Therefore, from the start of the change, the leading coil A
Until reaching A ₂ points above, the optimum curve R _A 'roll cross angle to along, to change the work roll bend force, the work roll bend force F _A' roll cross angle upon reaching the work roll bend force Is changed as soon as possible so as to have a value above the optimal curve R _B ′.
Roll cross angle along a _B ', to change the work roll bending force to the respective θ _B, F _B.

Accordingly, the time during which the work roll bending force, the roll cross angle, and the work roll shift amount deviate from the optimum curves R _A ′ and R _B ′, in other words, the time during which a plate shape defect occurs, is reduced by the work time. The roll bending force is changed from F _A ′ to F _B ′, and the roll cross angle is changed from θ _C to θ.
Only the time required to change _D and the work roll shift amount from δ ₁ ′ to δ ₂ ′ is sufficient, and it is possible to minimize the occurrence of plate shape defects.

The relationship between the roll cross angle, the work roll bend force, and the work roll shift amount can be easily calculated, and even if the change pattern of the work roll shift amount is complicated, the change can be performed in the same procedure. It is possible.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the present invention is applied to a tandem mill comprising five stands will be specifically described below. FIG. 2 is a block diagram showing the configuration of the running roll cross angle changing device according to the present invention. In the drawing, # 1 to # 5 denote first to fifth stands, and A and B denote coils having different dimensions. Is shown.

The rolling mills of the first and second stands # 1 and # 2 of the five stands constituting the tandem mill are provided with a work roll shift device having a tapered curve at the end and a work roll bend device. The rolling mills of the third to fifth stands # 3 to # 5 use ordinary rolling mills in which the roll axis is set in a direction perpendicular to the rolling direction. Coil A, B is coil B on the tail of coil A
Are connected in series by welding, and are continuously rolled through a tandem mill in the direction of the white arrow in the figure.

Each of the stands # 1 to # 5 is provided with a roll gap setting device 11 to 15 for the rolling mill and a roll speed setting device 21 to 25 for the rolling mill. The first and second stands # 1 and # 5 are also provided. Two
Are provided with roll cross angle setting devices 31 and 32 of the rolling mill, work roll bending force setting devices 41 and 42, and work roll shift amount setting devices 51 and 52, respectively.

Each of the roll gap setting devices 11 to 15 and the roll speed setting devices 21 to 25 have their respective stands calculated by the roll gap / roll speed setting change amount calculating device 40.
The roll gap and roll speed for each of # 1 to # 5, and the roll cross angle for each stand # 1 and # 2 calculated by the roll cross angle change amount calculation device 50 in each of the roll cross angle setting devices 31 and 32. However, each work roll bend force setting device 41, 42 has a work roll bend force change amount calculating device 80.
The work roll bend force for each stand # 1 and # 2 calculated in
1 and 52, the set work roll shift amounts for the stands # 1 and # 2 calculated by the work roll shift change amount calculating device 90 are input in accordance with the timing instruction signal from the setting change timing instruction device 70, respectively. It has become.

The roll gap / roll speed setting change amount calculation device 40, the roll cross angle change calculation device 50, the work roll bend force change amount calculation device 80, and the work roll shift change amount calculation device 90 are fetched from the coil information transmission device 60. Based on the information, a roll gap / roll speed for a coil to be rolled next, a roll cross angle change pattern as shown in FIG. 3 (b), and a work roll shift amount change pattern as shown in FIG. 3 (c) are calculated. Further, the work roll bend force change amount calculating device 80 calculates the work roll bend force in FIG. 3D based on the information taken from the coil information transmitting device 60 from F _A → F _A ′ → F _B ′ → F _B. A work roll bend force change pattern is calculated for the following.

The setting change timing instructing device 70 includes a point C for changing the rolling conditions, a connection point between the coils A and B, or
The point of changing the thickness in the coil is tracked over the area before and after the tandem mill, and immediately before reaching between the work rolls of each stand # 1 to # 5, the roll gap setting devices 11 to 15 of each stand # 1 to # 5. In contrast to the roll speed setting devices 21 to 25, the roll gap / roll speed setting change amount calculating device 40
And the roll cross angle from the roll cross angle change amount calculation device 50 for the roll cross angle setting devices 31 and 32, and the roll cross angle from the work roll bend force setting devices 41 and 42. Is the set work roll bend force from the work roll bend force change amount calculation device 80,
Then, the work roll shift amount setting devices 51 and 52 sequentially transmit the set work roll shift amount from the work roll shift change amount calculation device 90 to the timing signal to each of the roll gap setting devices 11 to 15, Output is made to the roll speed setting devices 21 to 25, the roll cross angle setting devices 31 and 32, the work roll bending force setting devices 41 and 42, and the work roll shift amount setting devices 51 and 52.

FIG. 3 shows the timing at which the rolling condition change point C (the point of connection between the coils A and B or the point where the sheet thickness is changed in the coil) passes between the work rolls in the first stand, the start of the change of the setting of each actuator, and FIG. 4 is an explanatory diagram showing a relationship with a setting change end timing. As shown in FIG. 3A, when an operation time for changing an actuator by a predetermined amount, that is, a change time is T, a connection point C is set to a work roll of a rolling mill. The actuator is actuated to start the change T / 2 hours before the point of passing the gap, and after the connection point C reaches between the work rolls, the change is controlled so that the change ends after T / 2 hours. . The actual changes in the roll cross angle, the work roll shift amount and the work roll bend force are started prior to this and ended later as shown in FIGS. 3 (b), 3 (c) and 3 (d). It will be.

The roll gap setting devices 11 to 15, the roll speed setting devices 21 to 25, and the roll cross angle setting device 3
Signals 1 and 32 output signals to a roll gap setting actuator, a roll drive motor, and a roll cross angle setting actuator (not shown), respectively.
The roll speed and roll cross angle are changed in a ramp-like pattern as shown in FIG.

The work roll bend force setting devices 41 and 42 output a signal to a work roll bend hydraulic unit (work roll bend force setting actuator), not shown, and make changes in a pattern as shown in FIG.

The work roll shift amount setting devices 51 and 5
2 outputs a signal to a work roll shift amount setting actuator (not shown), and changes the pattern in a pattern as shown in FIG. 3 (c).

In the above embodiment, the case where the roll cross angle is changed at the connection portion between the preceding coil and the following coil has been described. However, it is needless to say that the roll cross angle may be changed in the middle of one coil.

[0036]

As described above, in the apparatus of the present invention, the timing of changing the roll cross angle when continuously rolling a plurality of coils connected in series can be appropriately changed in accordance with the connection portion. It is possible to greatly reduce the coil length rolled under an inappropriate roll cross angle, and to minimize the shape defect portion due to the restriction speed of the roll cross angle change, and to reduce the width in the sheet width direction. The present invention has excellent effects, such as improvement in plate thickness accuracy and improvement in yield.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the device of the present invention.

FIG. 2 is a block diagram showing a configuration of a running roll cross angle changing device according to the present invention.

FIG. 3 is an explanatory diagram of control timing.

[Explanation of symbols]

# 1 to # 5 Stand 11 to 15 Roll gap setting device 21 to 25 Roll speed setting device 31, 32 Roll cross angle setting device 40 Roll gap / roll speed setting change amount calculation device 41, 42 Roll bending force setting device 50 Roll cross Angle change amount calculation device 51, 52 Work roll shift amount setting device 60 Coil information transmission device 70 Setting change timing indication device 80 Roll bend force change amount calculation device 90 Work roll shift change amount calculation device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Tomizawa, 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Prefecture Within Sumitomo Metal Industries, Ltd. (72) Inventor Kanji Hayashi 4-6-kannonshinmachi, Nishi-ku, Hiroshima, Hiroshima, Japan No. 22 Mitsubishi Heavy Industries, Ltd., Hiroshima Plant (72) Inventor Kazuo Morimoto 4-62 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd., Hiroshima Research Center (72) Inventor Osamu Miyamoto Kanon, Nishi-ku, Hiroshima City, Hiroshima Prefecture 4-6-22 Shinmachi Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (56) References JP-A-4-167909 (JP, A) JP-B 60-36330 (JP, B2) JP-B 2-39328 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21B 37/28 B21B 37/38

Claims (2)

(57) [Claims] In a process of continuously rolling a coil by a cross-roll type rolling mill including means for relatively moving an opposing roll in an axial direction and means for applying a roll bending force to the roll, In a running roll cross angle changing device configured to change the roll cross angle together with the roll relative movement amount and the roll bending force, means for instructing the roll cross angle setting change timing in accordance with the rolling condition change timing, A means for changing the set value of the roll cross angle based on the instruction of the means; a means for instructing the setting change timing of the roll relative movement amount in accordance with the timing of the rolling condition change; Means for changing the set value of the moving amount; means for instructing the setting change timing of the roll bending force in accordance with the timing of the rolling condition change; Instruction-fly roll cross angle changing apparatus characterized by comprising a means for changing the set value of the roll bending force based on the said means. 2. A means for determining a difference between a set roll cross angle with respect to a preceding coil and a set roll cross angle with respect to a succeeding coil prior to a timing of changing rolling conditions, and setting for a preceding coil prior to a timing of changing rolling conditions. Means for calculating a difference between the roll relative movement amount and a set roll relative movement amount with respect to a succeeding coil; and a means for calculating a change pattern of a roll bending force prior to a timing of changing a rolling condition. Item 2. The running roll cross angle changing device according to Item 1.