JP2888146B2 - Plate speed measuring apparatus and sheet thickness controlling method and apparatus for continuous rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a sheet speed in a continuous rolling mill equipped with a looper, and a method and an apparatus for controlling a sheet thickness by using the measured sheet speed.

[0002]

2. Description of the Related Art As a method for controlling the thickness of the sheet on the exit side of a continuous rolling mill, a thickness gauge is installed on the exit side of the final stand of the rolling mill, and the rolling position is determined based on the measured thickness. And controlling the rolling speed. However, in this method, since the thickness gauge cannot be installed immediately downstream of the final stand, control delay occurs due to dead time of the transport of the plate. That is, it takes time from when the plate passes through the final stand to when it reaches the thickness gauge. For this reason, the thickness of the plate measured by the thickness gauge has already passed through the rolling mill, and it is impossible to perform control without delay based on the measured value.

In order to solve this problem, a thickness gauge is installed on the entrance side of the first stand of the continuous rolling mill, and speedometers are installed on the entrance side and the exit side of each stand, respectively. A device for calculating the plate thickness immediately below each stand has been proposed in, for example, Japanese Patent Application Laid-Open No. 4-158912.

[0004]

However, even in the control of the sheet thickness based on the law of constant mass flow, when the present invention is applied to a continuous rolling mill in which a looper is installed between stands as in a hot rolling line, the following problem occurs. There is a problem.

[0005] When the rolling state changes during rolling, i-1
A deviation may occur between the outboard speed V _{i -1} of the ith stand and the inboard speed V _i of the _ith stand. For example, when v _i-1 > V _i , the looper rises to absorb the speed change between the stands. When the non-contact type speedometer is installed between the (i-1) th stand and the ith stand to measure the speed of the plate, or the speed of the plate is measured by measuring the rotation speed of the looper roller. In this case, the measured velocity V _i ^* takes a value between v _i−1 and V _i, and does not always satisfy V _i ^* = V _i . Also, the case of installing the speedometer between the i-th stand and (i + 1) -th stand is also necessarily v _i ^* = v _i can be explained similarly that not.

For this reason, the speeds of the plates on the entrance side and the exit side of each stand cannot be measured accurately, and a deviation occurs in the thickness in the thickness control based on the law of constant mass flow.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and accurately measures the speeds of the plates on the entrance and exit sides of each stand of a continuous rolling mill, thereby obtaining a thickness accuracy. It is an object of the present invention to provide a sheet speed measuring device for a continuous rolling mill, which makes it possible to reduce the off-gauge of a product by increasing the sheet speed, and a method and an apparatus for controlling the sheet thickness using the sheet speed measuring device.

[0008]

SUMMARY OF THE INVENTION In order to accurately measure the sheet speeds at the entrance and the exit of each stand of a continuous rolling mill, the present invention firstly measures the strip speed of a continuous rolling mill having the following structure. It is a device. That is, the present measuring device includes a looper roller tachometer for measuring a roller rotation speed of a looper installed between stands of a continuous rolling mill, a looper goniometer for measuring an angle of a looper arm of the looper, and a looper arm of the looper. From the measured values of the rotation speed of the looper roller, the angle of the looper arm, and the angular velocity of the looper arm measured by the looper roller speed meter, the looper angle meter and the looper angle speed meter, respectively, the exit side of the stand. And a first and a second calculation device for calculating the plate speed of the next stand and the plate speed on the entry side of the next stand, respectively.

Then, the thickness of the rolled material is controlled using the present measuring device. The first sheet thickness control method includes a step of measuring a sheet speed on an entrance side of a first stand of a continuous rolling mill, and a step of measuring a sheet speed on an entrance side of each stand from a second stand to a final stand of the continuous rolling mill. A step of measuring with the present measuring apparatus, a step of measuring the sheet speed at the exit side of each stand from the first stand to the last immediately preceding stand of the continuous rolling mill with the present measuring apparatus, and Measuring the side plate speed, calculating the ratio of the measured values of the inlet and outlet plate speeds, and lowering the stand based on the difference between the calculated plate speed ratio and the target value. Correcting the position.

[0010] The second method for controlling the thickness of the sheet is the first method for controlling the thickness of the continuous mill.
Measuring the thickness of the sheet on the entry side of the stand, measuring the sheet speed on the entry side of the first stand of the continuous rolling mill, and measuring the sheet thickness on the entry side of each stand from the second stand to the final stand of the continuous rolling mill. Measuring the sheet speed by the present measuring device; measuring the sheet speed on the exit side of each stand from the first stand to the last previous stand of the continuous rolling mill by the present measuring device; Calculating the sheet thickness on the outlet side of the stand by a mass flow method from the step of measuring the sheet speed on the outlet side of the stand and the measured values of the sheet thickness on the inlet side, the sheet speed on the inlet side, and the sheet speed on the outlet side. And a step of correcting the rolling position of the stand based on the difference between the calculated plate thickness value and the target value. In addition,
In the first and second plate thickness control methods, the plate speed on the entrance side of the first stand and the plate speed on the exit side of the final stand are measured by an ordinary plate speedometer.

[0011] A first thickness control method used in the first thickness control method may be used.
The sheet thickness control device measures the sheet speed on the entrance side of the stand of the continuous rolling mill, the present measuring device installed on the upstream looper, and measures the sheet speed on the exit side of the stand of the continuous rolling mill,
A main measuring device installed on a downstream looper, a calculating device for calculating a ratio of the measured values of the plate speeds on the inlet side and the outlet side, and a stand based on a difference between a calculated value of the calculating device and a target value. And a control device for controlling the rolling-down position.

The second thickness control device used in the second thickness control method includes a rolling mill entry side thickness gauge for measuring the thickness of the entrance of the first stand of the continuous rolling mill, A rolling mill entry side sheet speed meter that measures the entry side sheet speed of the first stand, and an upstream looper that measures the entry side sheet speed of each stand from the second stand to the final stand of the continuous rolling mill. The present measuring device, the present measuring device installed in a downstream looper for measuring the exit plate speed of each stand from the first stand of the continuous rolling mill to the last front stand, and the final measuring device of the continuous rolling mill. A rolling mill delivery side sheet speed meter for measuring the delivery side sheet speed of the stand, and from the measured values of the entry side sheet speed and the delivery side sheet speed, track the sheet thickness measured by the rolling mill entry side sheet thickness meter. A sheet thickness tracking device and the sheet thickness tracking device An arithmetic unit for calculating the sheet thickness on the outgoing side of the stand by the mass flow equation from the measured values of the sheet thickness on the incoming side, the sheet speed on the incoming side, and the sheet speed on the outgoing side. A control device for controlling the rolling position of the stand based on the difference between the value and the target value.

[0013]

In a continuous rolling mill equipped with a looper, the exit side plate speed of the stand on the upstream side of the looper and the entrance side plate speed of the stand on the downstream side of the roper are expressed by adding the angle and angular velocity of the looper arm to the rotation speed of the looper roller. it can. Therefore, even when the coordination between the stands is disturbed due to the change of the rolling conditions during the rolling of the plate, and a large vertical movement occurs in the looper installed between the stands, the output plate speed of the stand is measured by the measuring apparatus. And the entrance side plate speed of the next stand can be separated and accurately measured.

In the control of the thickness of the rolled material, first, a plate speed ratio is calculated from the entrance plate speed and the exit plate speed of each stand obtained by the present measuring device, and then the calculated plate speed ratio and target value are calculated. The thickness control is performed by correcting the rolling-down position of the stand based on the difference between the thickness and the stand.

[0015] Further, the outgoing plate of each stand is obtained by mass flow from the incoming plate speed and the outgoing plate speed of each stand obtained by the present measuring device, and the incoming plate thickness obtained by the incoming thickness gauge of the continuous rolling mill. Thickness is calculated by calculating the thickness, and correcting the roll-down position of the stand based on the difference between the calculated value of the output side thickness and the target value.

[0016]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the drawing, 10 ₁ ,..., 10 _n are n stands constituting a continuous rolling mill, 1 is a rolled material, 20 ₁ ,.
_n-1 is a looper installed between each stand, 21 ₁ , ...,
21 _n-1 is Ruparora tachometer that measures the rotational speed of the Ruparora, 22 _1, ..., 22 looper goniometer _n-1 is for measuring the angle of Rupaamu, 23 _1, ..., 23 _n-1
Is a looper angular velocity meter for measuring the angular velocity of the looper arm. Also, a rolling mill entry side thickness gauge 2 for measuring the entry side thickness and a rolling mill entry side plate speed meter 3 for measuring the entry side plate speed are installed on the entry side of the first stand 10 ₁ , and on the exit side of the final stand 10 _n. A delivery-side plate speedometer 4 for measuring the delivery-side plate speed is provided.

In the present embodiment, the plate speed measuring devices 30 ₁ ,..., 3
0 _n-1 are the looper roller rotational speeds ω _r1 ,..., Ω _rn-1 , the looper angle θ ₁ , and the looper roller rotational speeds measured by the looper roller speed meter, the looper angle meter, and the looper angle speed meter, respectively.
..., θ _n-1, and the looper angular velocity omega _L1, ..., by entering the omega _Ln-1, the side plate velocity v ₁ out of each stand,
..., v _n-1 and the entry side speed V ₂ of the next stand, ..., and it calculates a V _n. That is, each plate speed measuring device 30 _i (i = 1 to
n-1 and the same hereinafter. ) Is a looper roller tachometer 21 _i
When using the looper angle meter 22 _i, the measurements obtained from the looper angular velocity meter 23 _i, No. first arithmetic device for calculating the i stand 10 _i velocity v _i of the strip 1 the delivery side of the 30
A and No. i + 1 stand 10 Rolled material 1 on the entry side of _{i +} 1
And a second arithmetic unit 30B that calculates the speed V _{i + 1} of. The first stand 10 _one entry side speed V ₁ and the final stand 10 _n of delivery side speed v _n each rolling mill entry side speedometer 3, as measured by the side plate velocimeter 4 out rolling mill.

Further, in the present embodiment, the plate speed measuring device 30 _i
Of rolled material 1 based on the law of constant mass flow
Thickness control devices 41 and 42 for controlling the thickness of the sheet.

The plate thickness control device 41 is provided with the plate speed measuring device 30.
a side plate velocity v _i and entry side speed V _{i + 1} out of the stand obtained from _i, the entry side speed V ₁ of the first stand obtained from mill entry side speedometer 3, from the side plate speedometer 4 out rolling mill delivery side speed of the final stand obtained v with _n, the ratio of the side plate speed incoming and outgoing side plate speed of each stand R _i (R _i = v _i
/ V _i , where i = 1 to n. ), A second calculating device 41B for calculating a deviation ΔR _i between the plate speed ratio R _i and a target value R _i ^{* for} each stand, and a rolling-down position from the deviation ΔR _i. Correction amount Δ
Composed of the third arithmetic unit 41C for calculating the S _i.
The rolling position correction amount ΔS _i calculated by the present device 41 is
The rolling position control device 5 is sent to the rolling position control device 5.
To correct the rolling position of the stand by ΔS _i .

[0020] The thickness control device 42, the entry side thickness H ₁ of the rolling mill first stand 10 ₁ obtained from entry side thickness gauge 2 to just below the first stand, and from the first arithmetic unit 42B to be described later The resulting thickness of the outlet side of each stand h _i (i = 1
To n-1) to the position immediately below the next stand, respectively, and a plate speed measuring device _30i.
Obtained side plates speed v _i and entry side speed V _{i + 1} out of the stand more obtained, the mill entry side speedometer 3 entry side speed V ₁ of the first stand obtained from, from the side plate speedometer 4 out rolling mill and the side plate velocity v _n out of the final stand 10 _n to be the thickness at entrance side of each stand obtained from the tracking device 42A using H _{i + 1,} from each stand delivery side thickness h _i (here constant mass flow law, i = 1 to n) and the first arithmetic unit 42B for calculating a, composed of the second arithmetic unit 42C for calculating the delivery side thickness h _i from the pressing position correction amount [Delta] S _i. The rolling position correction amount ΔS _i calculated by the present device 42
Is sent to the rolling position control device 5, and the rolling position control device 5 corrects the rolling position of the stand by ΔS _i .

The plate thickness control device 42 controls the plate thickness based on the measured values of the plate thickness on the entrance side and the exit side of each stand and the plate speed. The thickness of the sheet is controlled based only on the measured values of the sheet speeds on the entrance side and the exit side. The two devices 41 and 42 are switched by the switch 6 in FIG.

Hereinafter, the plate speed measuring apparatus of the present invention will be described in detail with reference to FIG. When the side plate velocity v _i and i + 1 at entrance side velocity V _{i + 1} of the stand out of the i stands are equal, the looper angle θ does not vary. At this time, if the radius of the looper roller is r, the rotation angular velocity of the looper roller with respect to the looper arm axis is ω _r , and the angular velocity of the looper arm axis is ω _L , the equation (1) is established. v _i = V _{i + 1} = r · ω _r ′ (dθ / dt = 0) (1) where ω _r ′ = ω _r −ω _L

On the other hand, when v _i ≠ V _{i + 1} , this speed difference appears as a change in the length L of the rolled material between the stands. That is, _{dL / dt = v i -V i} + 1 (2). If the length of the rolled material from the i-stand to the i-looper is L ₁ and the length of the rolled material from the i-looper to the (i + 1) -th stand is L ₂ , L = L ₁ + L _2. Holds. _{dL 1 / dt + dL 2 /} dt = v i -V i + 1 (3) transposed to _{V i + 1 + dL 2 /} dt = v i -dL 1 / dt (4)

[0024] The formula (1), formula (4) than _{V i + 1 = r · ω} r '-dL 2 / dt (5) v i = r · ω r' + dL 1 / dt (6) In addition, dL ₁ / Dt = dL ₁ / dθ · dθ / dt (7) dL ₂ / dt = dL ₂ / dθ · dθ / dt (8) dθ / dt = ω _L where dL ₁ / dθ and dL ₂ / dθ are It is uniquely determined by the functions f ₁ (θ) and f ₂ (θ) determined by the geometrical arrangement of the stand and the looper disposed therebetween.

As described above, the output side plate speed v _i of the i-stand
And the entry side plate speed V _{i + 1} of the (i + 1) th stand can be separately detected. Therefore, even if the rolling conditions change during rolling, the incoming plate speed and the outgoing plate speed can be detected independently for each stand. It is possible to control the thickness without delay, and it is possible to improve the thickness accuracy.

The operation of the thickness control devices 41 and 42 of the present embodiment will be described below.

[0027] The thickness at entrance side of the i stand and H _i, the thickness at delivery side of the i stand and h _i, a plate speed of the i stand entry side measured by the plate speed measuring device provided i stand upstream of i-1 looper Is set to V _i, and the plate speed on the exit side of the i-stand measured by the plate speed measuring device provided on the i-looper downstream of the i-stand is set to v _i .

[0028] The constant mass flow law is a _{H i · V i = h i} · v i (9).

By transforming equation (9), equation (10) is obtained. _{H i / h i = v i} / V i = R i (10)

First, the plate thickness control device 41 uses the first arithmetic unit 41A to set the entry side plate speed of the i stand to V _i , i
The exit side plate speed of the stand is calculated as a ratio R _{i of} v _i . Next, the second arithmetic unit 41B calculates the rolling-down position correction amount ΔS _i based on the equation (11) so that the deviation between the calculated value R _i and the target value R _i ^* becomes zero. ΔS _i = f (R _i −R _i ^* ) (11) By outputting this ΔS _i to the rolling position control device 5, the rolling position control device 5 performs an operation of correcting the rolling position of the i stand by ΔS _i. .

The first arithmetic unit 42B of the plate thickness control unit 42 calculates the output side plate thickness h of the i-stand based on the equation (10).
Calculate _i . Next, the second arithmetic unit 42C calculates the arithmetic value h
_The rolling-down position correction amount ΔS _i is calculated based on the equation (12) so that the deviation between _i and the target value h _i ^* becomes zero. ΔS _i = f (h _i −h _i ^* ) (12)

While the embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and other modifications having the structure of the present invention do not depart from the present invention.

[0033]

As described above, according to the plate speed measuring apparatus of the present invention, the plate speed detected by the rotation speed of the looper roll can be corrected by the angle and the angular speed of the looper arm. And the entrance side plate speed of the stand downstream of the looper can be separated and measured with high accuracy.

Further, according to the sheet thickness control method and apparatus of the present invention, the sheet thickness can be controlled with high accuracy using the sheet speed measured by the above-mentioned sheet speed measuring device.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram for finding outboard speeds and outboard speeds.

[Explanation of symbols]

1 rolled material 2 rolling mill entry side thickness meter 3 mill entry side speed four mill delivery side speedometer 5 rolling position control device 10 _1, ..., 10 _n stands 20 _1, ..., 20 _n-1 looper 21 _1, , 21 _n-1 looper roller tachometer 22 ₁ , ..., 22 _n-1 looper angle tachometer 23 ₁ , ..., 23 _n-1 looper tachometer 30 ₁ , ..., 30 _n-1 plate speed measurement device 30A 1st Calculation device 30B Second calculation device 41, 42 Thickness control device 41A First calculation device 41B Second calculation device 41C Third calculation device 42A Tracking device 42B First calculation device 42C Second calculation device

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification symbol FI B21C 51/00 B21B 37/12 BBK 111B (56) References JP-A-8-155519 (JP, A) JP-A-5-337530 (JP, a) JP flat 9-52107 (JP, a) JP flat 4-361810 (JP, a) JP flat 1-162507 (JP, a) (58 ) investigated the field (Int.Cl. ⁶ , DB name) B21C 37/00 B21C 51/00

Claims (5)

(57) [Claims] 1. A looper roller tachometer for measuring a roller rotation speed of a looper installed between stands of a continuous rolling mill; a looper goniometer for measuring an angle of a looper arm of the looper; and an angular speed of a looper arm of the looper. A looper gyro to measure the rotation speed of the looper roller, the angle of the looper arm, and the angular velocity of the looper arm measured by the looper gyro and the looper gyro, respectively, from the measured value of the exit side plate of the stand. A calculating device for calculating the speed and the plate speed on the entry side of the next stand, respectively, a plate speed measuring device for a continuous rolling mill. 2. The step of measuring the sheet speed on the entry side of the first stand of the continuous rolling mill, and the sheet speed on the entry side of each stand from the second stand to the final stand of the continuous rolling mill. A step of measuring the sheet speed on the outgoing side of each stand from the first stand to the last previous stand of the continuous rolling mill by the sheet speed measuring apparatus according to claim 1. Measuring the sheet speed on the outlet side of the final stand of the continuous rolling mill; calculating the ratio of the measured values of the sheet speeds on the inlet side and the outlet side; and the calculated sheet speed ratio and target value. Correcting the rolling position of the stand based on the difference in the thickness of the stand. 3. A step of measuring a thickness of a sheet on an entrance side of a first stand of the continuous rolling mill, a step of measuring a sheet speed on an entrance side of the first stand of the continuous rolling mill, and a second stand of the continuous rolling mill. A step of measuring the sheet speed of each stand from the first stand to the last stand by the sheet speed measuring device according to claim 1, and the outlet side of each stand from the first stand to the last front stand of the continuous rolling mill. A step of measuring the sheet speed of the final stand of the continuous rolling mill, a step of measuring the sheet speed of the final stand of the continuous rolling mill, and a sheet thickness of the entrance side and a sheet velocity of the entrance side. And calculating the sheet thickness on the outlet side of the stand by the mass flow equation from the measured value of the sheet speed on the outlet side, and the rolling-down position of the stand based on the difference between the calculated sheet thickness value and the target value. And correcting the following. A method for controlling the thickness of a continuous rolling mill. 4. The plate speed measuring device according to claim 1, which is installed on an upstream looper for measuring the plate speed on the entrance side of the stand of the continuous rolling mill, and the plate speed on the exit side of the stand of the continuous rolling mill. The plate speed measuring device according to claim 1, which is installed in a downstream looper, and a calculating device that calculates a ratio of a measured value of the plate speeds on the inlet side and the outlet side; and a calculated value of the calculating device. A control device for controlling a rolling position of the stand based on a difference between the control value and a target value. 5. A rolling mill entry side thickness gauge for measuring the entry thickness of the first stand of the continuous rolling mill, and a rolling mill entry side sheet speed for measuring the entry speed of the entry side of the first stand of the continuous rolling mill. A sheet speed measuring device according to claim 1, which is installed on an upstream looper for measuring a sheet speed on an entrance side of each stand from a second stand to a final stand of the continuous rolling mill; The sheet speed measuring device according to claim 1, which is installed in a downstream looper for measuring the sheet speed on the exit side of each stand from the first stand to the last front stand, and the exit of the last stand of the continuous rolling mill. Rolling mill exit side sheet speed meter to measure the side sheet speed, From the measured values of the entrance side sheet speed and the exit side sheet speed, sheet thickness tracking to track the sheet thickness measured by the rolling mill entry side sheet thickness meter Device and the thickness tracking device. An arithmetic unit for calculating the thickness of the outlet side of the stand by the mass flow equation from the measured values of the rack thickness on the entry side, the thickness of the entrance side, and the thickness of the exit side, and the calculated value of the arithmetic unit A control device for controlling a rolling position of the stand based on a difference between the control value and a target value.