JP3446398B2 - Control method and device for die rolling mill - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to shortening the time between passes by stabilizing the rolling material stop position after leaving a mill when performing reverse rolling in a steel mold facility, and increasing the rolling speed by increasing the rolling time. For the purpose of shortening, the mill reduction ratio (rolled material cross-sectional area ratio) between the previous pass and the current pass and the actual length of the previous pass rolled material are predicted and calculated using this data. The present invention relates to a mill and a rolling mill control method for operating table speeds on the front and rear surfaces of the mill.

[0002]

2. Description of the Related Art As a conventional control method for stopping a rolled material at a predetermined position, there is a hot metal detector (hereinafter referred to as HMD) installed on the side of a rolling line as described in JP-A-52-155164. Using the so-called rolled material detector, the current position of the rolled material by the signal from the HMD, the moving speed of the rolled material, and the distance (fixed length) data from the HMD to a predetermined stop position are calculated in the control computer, There is a method of outputting a speed command to the control device.

[0003]

However, this method is effective when the environment of the installation location of the HMD is good or when the operating speed is low, but in reality, the roll or the rolled material is cooled near the mill. There arises a problem that the HMD is erroneously detected by water vapor or the like. Further, in order to increase production efficiency, the operating speed has been increased, and if the processing is started based on the detection result, an operation delay of the operating speed command occurs.

In the present invention, the remaining length is calculated from the predicted rolling material length data calculated from the mill reduction ratio (rolling material sectional area ratio) of the previous pass and the current pass and the actual rolling length without using the detector such as HMD. (EN) A control method of grasping and operating a speed command so as to decelerate or stop when a predetermined remaining length is reached.

[0005]

Means for Solving the Problems A pair of upper and lower rolling rolls and a pair of left and right rolling rolls are provided, and the plate material is passed through the upper and lower and left and right rolling rolls a predetermined number of times to obtain a desired plate thickness and plate width. In the model steel rolling machine for rolling to, the cross-sectional area ratio of the plate material by the previous rolling and the current rolling, the length of the plate material by the current rolling is calculated from the length of the plate material by the previous rolling, and based on the obtained result. The above problem is solved by controlling the roll speed of the shaped steel rolling mill.

In the above control method, if the length of the sheet material after the current rolling is compensated on the basis of the error between the length of the sheet material obtained by the previous rolling and the actual length of the sheet material, the accuracy is further improved. A good plate length can be obtained.

Further, in the above control method, the length of the plate material by the current rolling is calculated from the actual reduction amount of the current rolling.
By recalculating, a more accurate plate length can be obtained.

Further, the present means calculates the cross-sectional area ratio of the plate material by the previous rolling and the current rolling, and the length of the plate material by the current rolling from the length of the plate material by the previous rolling. This can be realized by providing the second calculating means to be obtained and the control means for controlling the roll speed of the shape steel rolling mill based on the results obtained by the first and second calculating means.

[0009]

A pair of upper and lower rolling rolls and a pair of left and right rolling rolls are provided, and the plate material is passed through the upper and lower and left and right rolling rolls a predetermined number of times, and reverse rolling is performed so that the plate material has a desired plate thickness and plate width. In the steel rolling mill for rolling, by determining the cross-sectional area ratio of the plate material by the previous rolling and the current rolling, the length of the plate material by the current rolling from the length of the plate material by the previous rolling, By predicting the remaining rolling length and controlling the roll speed of the model steel rolling mill, it is possible to stabilize the rolling material stop position after leaving the model steel rolling mill.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

First, the flat steel, which is one of the products of the die rolling mill, will be described.

FIG. 1 is a diagram showing the configuration of the present invention. The target model rolling mill has two upper and lower horizontal rolls 1 and 2 that vertically roll down, and two rolls on the upstream side of the horizontal rolls 1 and 2 that horizontally roll down (only one side is shown in the figure). It has a vertical roll 3 of No. 1 and performs reverse rolling to obtain a desired plate thickness by passing the rolled material through the shaped steel rolling mill several times. Speed feedback S detected from the shape rolling mill (mill) by the speed detector 4 attached to the mill motor
The FB and the actual rolling reduction G are transmitted to the control computer 10. The control computer 10 includes a speed conversion unit 6 for speed conversion from the speed feedback SFB 6, a length conversion unit 5 for integrating the length from the time when the die rolling mill bites the rolled material 5, and rolling reduction information for each pass of the rolling mill. And a predicted material length calculation unit 8 and a length conversion unit 5 that predict the rolled material length of the current pass together with the input values of the previous pass, current pass reduction data, and previous rolled material length actual data. Comparison of the actual rolled length of the current pass and the predicted length of the current pass accumulated by the calculation, and the remaining length L of the rolled material until the rolled material leaves the mill L
The comparison unit 7 that outputs RE to the speed command calculation unit 9, the remaining length of the rolled material until it leaves the mill is monitored at any time, and is calculated together with the current pass speed SFB of the rolled material, and when the predetermined remaining length is reached, Deceleration and stop commands (speed command SREF) are sent to the mill controller 1
1 is composed of a speed command calculation unit 9. Also,
When there is no rolled material data when the rolled material first passes through the shaped steel rolling mill, the input data 12 is provided for the actual data from the upstream mill or for the operator.

Next, the current path predicted material length calculation performed by the predicted material length calculation unit 8 will be described with reference to the flow chart of FIG. The data required for calculating the current pass predicted length is the actual length of the previous pass rolled length L,
And the previous pass rolled material sectional area A, the current pass planned rolled material sectional area A ′, the current pass rolled material sectional area result Ar, and the correction coefficient α. The previous-pass and current-pass rolled material cross-sectional area results A and Ar are obtained from the opening results of the horizontal rolls 1 and 2, and the opening results of the vertical roll 3.

The current pass planned rolling material cross-sectional area A'is obtained by the predicted material length calculation unit 8 referring to the planned value of the roll opening determined by a predetermined rolling schedule simultaneously with the updating of the pass number. There is. The method of obtaining the previous-pass rolled material length L and the correction coefficient α will be described later. Further, during the first pass, since there is no previous pass rolled material length actual L and previous pass rolled material cross sectional area actual A, it is given by an upstream mill or an input from an operator. Next, the calculation method and meaning of each data will be described. First, the cross-sectional area A will be described with reference to FIG. FIG. 3A shows the reduction in the previous pass, and FIG. 3B shows the reduction in the current pass (planned).

A rolled material 13 is surrounded by the horizontal roll 1, the horizontal roll 2 and the vertical roll 3. Since the vertical roll 3 is located upstream of the horizontal rolls 1 and 2,
It is indicated by a broken line. The specifications of rolled material are mainly determined by width W and height H. The width W is the opening V and the height H of the vertical roll 3.
Is created by the opening degree HR of the horizontal rolls 1 and 2.

Therefore, the actual cross-sectional area A of the front pass rolled material is         A = left / right roll opening V × upper / lower roll opening HR (1) Required by. Similarly, the cross-sectional area A'of the current planned rolling material is         A ′ = V ′ × HR ′ (2) Required by.

Also, the actual cross-section area Ar of the current pass rolled material can be obtained by the same calculation as in the equation (1).

Next, the correction coefficient α will be described. As can be seen from FIG. 3, the width W depends on the opening (rolling down amount) of the upper and lower rolls.
There is some extension from the width W made by the left and right rolls 3 in the direction. As a result, there is an error between the predicted material length and the actual rolled material length after the pass. For the actual length of rolled material after the pass, use the load cell (load cell) attached to the rolling mill to bite the rolled material in the mill (load on) and remove the rolled material from the mill (load off).
Is detected and the rolling roll rotation number N and the effective radius r are detected during this period, the actual rolled material length L after the pass is obtained by L = 2 × π × r × N (3)

The correction coefficient δ is a coefficient for correcting the error between the actual rolled material length after the end of the pass and the predicted material length obtained by the equation (3).
Is. The correction coefficient δ is obtained by δ = actual length of previous pass rolled material L / predicted length of previous pass L ′ (4) and is used when calculating the estimated length of the current pass. However,
If the current pass expected cross-sectional area A'is larger than or equal to the previous pass actual cross-sectional area A (that is, no reduction), δ =
Set to 1.

Based on the thus obtained cross-sectional area A of the rolled material before the pass, the cross-sectional area A'of the current planned rolling material, the actual length L of the rolled material after the pass, and the correction coefficient δ, the following equation is used. The current path predicted material length L'is calculated.

L ′ = L × A / A ′ × δ (5) The current path predicted material length calculated by the equation (5) is output from the predicted material length calculation unit 8 in FIG. 1 to the comparison unit 7.

Next, when a predetermined remaining length before the deceleration start remaining length Ld, which will be described later, is reached, the current path predicted material length L'is calculated by the following equation.
To recalculate.

L ′ = L ′ × A ′ / Ar (6) The predicted path length of the current path obtained by the equation (6) is output from the predicted length calculation section 8 to the comparison section 7 as the final predicted length. . The comparison unit 7 repaints the previous predicted material length with the final predicted material length obtained by the equation (6).

The above operation is performed for each pass until the end of the final pass. The rolled material remaining length LRE is calculated from the current path predicted material length L'to the number of revolutions N accumulated in the length conversion unit 5 from the biting of the rolled material to the present time at each predetermined scan time of the control computer 10.
It is obtained by subtracting LR obtained by substituting R into N of the equation (3) in the comparison unit 7.

Next, a method for obtaining deceleration start / stop residual length from the rolling material residual length LRE up to the current pass mill exit and the actual rolling speed, and the acceleration / deceleration α of the mill, which is performed in the speed command calculation unit 9, will be described with reference to FIG. explain. FIG. 4 is a diagram showing the state of the rolling speed from when the material enters the mill to when it exits the mill and stops. The rolling speed has two speeds, a top speed Vt and a creep speed Vc. Creep speed Vc
Is when the rolled material is biting and when the rolled material is out of the mill,
The speed is set so that the rolled material easily bites into the mill and does not cause damage as much as possible.

First, the stop remaining length Ls will be described. The remaining stop length Ls is a distance required from the output of the stop command to the stop, which corresponds to the area 14 in FIG.

Therefore, Ls = (Vc × Vc-0 × 0) / (2 × α) (7) Next, a method for calculating the deceleration start remaining length Ld will be described. The deceleration start remaining length Ld is the stop remaining length, the area 1 in FIG.
This is the distance obtained by adding area 15 to 4.

Therefore, assuming that the creep speed time is tc,         Ld = Ls + Vc × tc + (Vt × Vt−Vc × Vc) / (2 × α)                                                             … (8) Becomes

These LS and Ld are compared with the remaining length LRE of the rolled material, and a deceleration command is output to the mill controller 11 when LRE≤Ld and a stop command is output to the mill controller 11 when LRE≤Ls. Controls the roll speed of the shape rolling mill.

Further, an H-section steel, which is another product of the section steel rolling mill, will be described as an example.

FIG. 5 is a diagram showing the configuration of the present invention. The two upper and lower horizontal rolls 1 and 2 have a mechanism for vertically reducing, and the two left and right (only one side is shown in the figure) vertical rolls 3 have a mechanism for horizontally reducing. From the mill, the speed feedback SFB detected by the speed detector 4 attached to the mill motor and the actual rolling reduction G are transmitted to the control computer 10. The control computer 10 can be realized with the same configuration as flat steel. In addition, basically, the process of calculating the predicted length of the current path and the state of the rolling speed from the time when the material enters the mill to the time when it exits the mill and stops will be described as the same as the flat steel.

Next, the calculation method and meaning of each data will be described. First, the cross-sectional area A will be described with reference to FIG. FIG. 6A shows the reduction in the previous pass, and FIG. 6B shows the reduction in the current pass. The rolled material 13 is surrounded by the horizontal roll 1, the horizontal roll 2 and the vertical roll 3. The specifications of the rolled material are determined by width W, height H, web thickness WE, and flange thickness F. Among them, the width W and the height H correspond to various specifications by changing the rolling rolls. The remaining web thickness WE and the flange thickness F are produced by the reduction of the mill.

The previous cross sectional area A of rolled material is   A = H × (left roll opening L + right roll opening R) + WE × upper and lower rolling roll width D                                                             … (9) Required by. Similarly, the cross-sectional area A'of the current planned rolling material is     A ′ = H × (left roll opening L ′ + right roll opening R ′) + WE ′           × Upper and lower rolling roll width D (10) Required by.

Also, the actual cross-sectional area Ar of the current pass rolled material can be obtained by the same calculation as the equation (1).

The correction coefficient α, the speed command calculation unit 9 calculates the deceleration and stop remaining lengths from the rolling material remaining length up to the current pass mill removal and the actual rolling speed, which is also the same as that of the flat steel. .

Then, similarly to the case of the flat steel described above, when rolling is started, it is judged whether or not it is a first pass (first rolling), and if it is a first pass, it is before the upstream mill or the operator input value. The path length and the cross-sectional area A of the previous path are calculated, and the correction coefficient is set to 1, and the current path predicted length L '
Is calculated from Equation 5. Then, the remaining rolling length LRE is calculated by the same method as described above, and it is determined whether the deceleration length Ld or the stop command length is reached, and the roll speed is controlled. In this way, the rolling is completed a predetermined number of times and the rolling is completed.

[0037]

As described above, in order to stabilize the stop position of the rolled material after leaving the mill, the current path predicted material length is calculated,
By comparing the actual length with the actual rolling length, the remaining length of the rolled material until it comes out of the mill is grasped, and the speed of the mill and the front and rear surface table of the mill are controlled based on the remaining length and the actual rolling speed.

As a result, there is no need to use the HMD and there is no need to discuss the environment around the mill. Also, HMD
When using a roll (especially when it has to be installed in the immediate vicinity of the mill), the remaining length of the rolled material until it comes out of the mill must be recognized as a fixed length (the length from the HMD material detection position to immediately below the mill). Although the speed is limited, in the present invention, since the remaining length of the rolled material until the mill is removed can be recognized as variable data, the rolling speed can be increased and the rolling time can be shortened. Further, since the stop position of the rolled material after leaving the mill is stable, the time between passes can be shortened and the rolling time can be shortened as a whole, improving the productivity.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a control method of the present invention.

FIG. 3 is a diagram showing a rolled state of a rolled material.

FIG. 4 is a diagram showing a state of rolling speed from when the material enters the mill to when it exits the mill and stops.

FIG. 5 is a block diagram showing the overall configuration of another embodiment of the present invention.

FIG. 6 is a diagram showing a rolled state of another rolled material of the present invention.

[Explanation of symbols]

1, 2 ... Horizontal roll, 3 ... Vertical roll, 4 ... Speed detector, 13 ... Rolled material.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-57-170083 (JP, A) JP-A-53-96955 (JP, A) JP-A-54-112368 (JP, A) JP-A-55- 126312 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 37/00-37/78

Claims (4)

(57) [Claims] 1. A mold steel comprising a pair of upper and lower rolling rolls and a pair of left and right rolling rolls, and rolling the plate into a desired thickness and width by passing the plate through the upper and lower and left and right rolling rolls a predetermined number of times. In the control method of the rolling mill, the sectional area ratio of the plate material obtained by the actual reduction amount of the previous rolling and the planned reduction amount of the current rolling, the planned length of the sheet material by the current rolling from the length of the sheet material by the previous rolling And controlling the roll speed of the shaped steel rolling mill based on the obtained result. 2. The planned length of the sheet material by the current rolling according to claim 1, based on the error between the planned length of the sheet material by the previous rolling and the actual length of the sheet material by the previous rolling. A method for controlling a section rolling mill, comprising: 3. The method according to claim 1, wherein when the plate material has a predetermined remaining length, the planned length of the plate material by the current rolling is again obtained from the actual reduction amount of the current rolling, and the obtained result is obtained. The method for controlling a model steel rolling machine is characterized in that the roll speed of the model steel rolling machine is controlled based on the above. 4. A shape steel comprising a pair of upper and lower rolling rolls and a pair of left and right rolling rolls, and rolling the plate into a desired thickness and width by passing the plate through the upper and lower and left and right rolling rolls a predetermined number of times. In the rolling mill, the first calculation means for obtaining the sectional area ratio of the plate material from the actual reduction amount of the previous rolling and the planned reduction amount of the current rolling, and the plate material of the current rolling from the length of the plate material of the previous rolling And a control means for controlling the roll speed of the shape rolling mill based on the results obtained by the first and second calculation means. Rolling mill.