JP2984187B2 - Advanced rate measurement method using non-contact plate speed meter in hot tandem mill - 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 for measuring an advanced rate in a hot tandem mill.

[0002]

2. Description of the Related Art There is known a rolling technique in which the advance ratio of a rolling mill in a hot tandem mill affects the product strip size and introduces the advance ratio for high precision control of the strip size. Conventionally, as disclosed in, for example, JP-A-63-281707 and JP-A-2-20605, a looper roller contact type sheet speed meter or a laser is provided on the exit side of each stand of a finishing tandem rolling mill. A non-contact speedometer is installed to measure the speed of the material to be rolled, while the peripheral speed of the rolling roll is measured, and the advance rate is calculated from the difference.

[0003]

However, on the exit side of the stand where the non-contact plate speedometer is installed, a large amount of cooling water for work roll for rolling and cooling water for temperature control of the strip is scattered, and the measurement environment is poor. Long-term stable measurement is difficult with a non-contact plate speedometer. Regarding the environmental properties of the non-contact plate speedometer, the inventors conducted an atmosphere investigation and experiment on an actual hot tandem rolling mill, and found that a looper device and a looper were used.
The best atmosphere is at the position between the rolling machine and the rolling mill adjacent to the rolling material in the traveling direction of the material to be rolled. Measurement is difficult. Further, when the sensor installation is not taken into consideration from the construction, the installation space is limited to an extremely narrow range by the looper shaft, and it is difficult to perform maintenance and even simple waterproofing measures. Also, the measurement from the upper part of the strip was difficult due to the water on the strip surface.

[0004] On the other hand, in a sheet speedometer of a looper roller contact type,
The stability of measurement accuracy was insufficient due to roller wear and the like.

According to the present invention, when a non-contact plate speed meter is installed between hot tandem mill stands, the rate of advance of the mill can be measured over a long period of time by bypassing poor environmental conditions such as splashing of cooling water. It is intended to provide a measuring method.

[0006]

According to the present invention, a non-contact plate speed meter is installed between a looper device between stands and a rolling stand downstream from the looper device in the traveling direction of the material to be rolled. The looper height of the looper device is measured, the stand-to-stand loop amount and its differential value are calculated from the measured value in a minute time cycle, and the measured value of the non-contact plate speedometer is used as the differential value of the loop amount. Using the corrected sheet speed value and the roll peripheral speed of the upstream rolling stand of the looper device, the exit advance rate of the upstream rolling stand of the looper device is calculated.

[0007]

Between the looper device and the rolling stand on the downstream side in the traveling direction of the material to be rolled from the looper device, the work roll cooling water in the upstream stand and the downstream stand and the cooling water for strip temperature adjustment and the like are provided. The work roll cooling water of the upstream stand and the cooling water for strip temperature adjustment (board water) on the upper surface of the rolled material, which is substantially free of scattering, is lifted upward by a looper roller. (Or pushed down) and flows out of the rolled material,
On the downstream side of the looper device, it does not substantially exist on the upper surface of the rolled material. In the present invention, since the non-contact plate speedometer is installed at such a position, the speed of the rolled material there can be measured stably for a long period of time.

However, the advanced rate to be obtained is
This is a part on the exit side of the upstream rolling stand with respect to the pallet device, and is passed through the looper device during the measurement, so that a speed disturbance due to a loop fluctuation between stands is accompanied. That is, as shown in FIG. 1, the non-contact plate speed meter 3 disposed between the looper roller 4 and the downstream rolling stand _{Fi + 1 in the} rolling material traveling direction from the looper roller 4 is used. measurement speed is Le - Palo - to delivery side speed of the rolling stand F _i which is adjacent to the upstream side of La 4, Le - loop amount variation is combined sum by Pas height variations. Therefore, in the present invention, the looper height of the looper is measured, and the loop amount between stands and its differential value are calculated from the measured value in a minute time cycle, and the measured value of the non-contact plate speedometer is calculated. The sheet speed value after correction by correcting with the differential value of the loop amount,
Using the roll peripheral speed of the upstream rolling stand of the looper roller, the exit advanced rate of the upstream rolling stand of the looper roller is calculated.

[0009] The, the contents of the calculation of the exit side forward slip of the upstream roll stand F _i, will be described herein in more detail, forward slip to be obtained here Le - Paro - La 4 on the upstream side are those of the exit side of the adjacent rolling stand F _i. And the side plate velocity V _M out of the upstream roll stand F _i, the relationship of the non-contact plate speed meter 3 measurement plate speed V _S and the loop amount of variation ΔL can be represented by the following equation (1).

V _M = V _S + ΔL ÷ Δt (1) Δt: sampling time (small time period) In FIG. 1, the loop amount variation ΔL is obtained by the following equation (2).

H = L _r · sin θ−L _Y + R _L L ₁ = L _XX −L _r · cos θ L ₂ L _X = L _X + L _r · cos θ Loop 1 = √ (H ² + (L ₂ L _X ) ² ) Loop 2 = Ｈ (H ² + L ₁ ² ) L = Loop ₁ + Loop 2 (2) H: Vertical height between the contact point between the strip-luper and the pass line Strip = rolled material θ: Looper angle L _Y : Vertical height between the pass line and the loop pivot axis R _L : Radius of the loop roper L ₁ : Horizontal distance between the contact point of the strip looper and the Fi _{+ 1} stand L _r : Length of loop arm L _XX : Le - Papibotto axis to F i _{+ 1} between the horizontal distance L ₂ L _X: F _i stand-strip Le - between Pas contact points horizontal distance L _X: F _i stand ~ Le - Papibotto axis between the horizontal distance L: inter-stand full Loop amount The loop amount variation ΔL for each sampling time Δt is obtained by substituting the measured looper angle θ into equation (2). Calculated by the following equation (3) by Rukoto.

ΔL = L (previous value) −L (current value) (3) L (previous value): calculated value Δt before this time: From the above equations (1) to (3), the loop La 4 and Lu
The inter-stand loop amount differential value ΔL is corrected using the measured value of the non-contact plate speed meter 3 arranged between the parlor 4 and the rolling stand _{Fi + 1} on the downstream side with respect to the traveling direction of the rolled material 2. by the side plate velocity V _M out of the upstream roll stands F _i le - can be obtained disturbance without by Pas height variations, and the side plate velocity V _M out rolling mill obtained here, Le - Paro - forward slip by rolling mill roll peripheral speed N _M adjacent upstream from La is calculated by the following equation (4).

The advance rate (%) = (V _M −N _M ) ÷ N _M × 100 (4) As described above, the bypass of the poor environmental conditions such as the scattering of the cooling water is performed,
A stable mill exit side advance rate can be obtained.

[0014]

FIG. 2 is a diagram showing the structure of an apparatus for carrying out the method of the present invention. In the drawing, _Fi 1 denotes an upstream side of a finish rolling mill for rolling a rolled material 2 with respect to a loop roller 4. Side (in the flow direction of the rolled material). 3 is
A non-contact type sheet speed meter for measuring the speed of the rolled material 2, a looper roller 4 for supporting the rolled material 2 and a rolling stand F on the downstream side.
It is arranged between _{i + 1 and} 5. Reference numeral 6 denotes a tachometer such as a pulse generator.
Are mechanically connected in series via a spindle and a mill motor. 7 is a high-speed scanning rule
It is a PC controller, and repeatedly acquires a looper angle measured by, for example, a tachometer such as a pulse generator in a minute time cycle, and loops the loop angle to the plate speed calculating device 8 for each acquisition.
Transmit the angle signal.

The plate speed calculator 8 uses the signal (plate speed V _S ) of the non-contact plate speed meter 3 and the looper angle signal θ to correct the loop length according to the above equations (1) to (3). Perform the operation,
The output side plate speed V _M of the upstream stand F _i 1 is calculated, and a signal representing this is supplied to the advanced rate calculation device 9. Advanced ratio calculating unit 9 includes a plate velocity V _M, using a roll peripheral speed N _M, which is calculated from the rotation speed meter 6 (4) performs the calculation of equation, the exit side advanced of the upstream-side stand F _i 1 Then, it is transmitted to the host computer 10.

[0016]

Effects of the Invention Figure 3, the exit side advanced measurement results of the rolling stand F _i of the hot tandem rolling at a finishing mill, the calculation of the non-contact plate speed meter 3 in measurement speed Vs and the plate speed calculating device 8 together with the plate velocity V _M. The dotted line in the graph indicating the advanced rate indicates an outline of the calculated value of the advanced rate calculating device 9. Since the calculated value is calculated by the advanced rate calculating device 9 in a minute time cycle, it is a graph finely vibrating below and above the dashed line in the figure. The dashed line indicates the center value of the vibration. Since the non-contact speedometer 3 is disposed between the looper 4 and the downstream rolling stand F _{i + 1} ,
There is no water riding on the rolled material 2 and the rolling stands F _i
Since there is no scattering of the work roll cooling water and the strip temperature adjusting cooling water of F _{i + 1} , the measurement noise of the non-contact plate speedometer 3 is small, and a stable advanced rate calculation value is obtained. FIG. 4 shows the measurement failure rate. According to the present invention, the measurement failure rate is 0%, and stable measurement can be performed.

[Brief description of the drawings]

FIG. 1 shows an arrangement position of a non-contact plate speed meter 3 according to the present invention;
It is a side view which shows the amount of loops before and after the loop roller 4.

FIG. 2 is a block diagram showing an apparatus configuration for implementing the method of the present invention in one aspect.

3 is a graph showing an example of output values of an advanced rate calculating device 9, a non-contact plate speed meter 3 and a plate speed calculating device 8 shown in FIG. 2, wherein an upstream rolling stand F _i 1 shown in FIG. This is a case where the finish of the hot tandem rolling mill is # 4 mil.

FIG. 4 is a graph showing an advanced rate measurement failure rate.

[Explanation of symbols]

1: Upstream rolling stand of finishing mill 2: Rolled material 3: Non-contact plate speedometer 4: Looper roller 5: Downstream stand of finishing mill 6: Revolution counter 7: Looper controller 8: Plate Speed calculator 9: Advanced rate calculator 10: Host computer

Continuation of the front page (72) Inventor Yoshiaki Kojima 1 Nishinosu, Oita-shi, Nippon Steel Corporation Oita Works (56) References JP-A-2-20605 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) B21B 37/16 B21B 37/28 B21B 38/00

Claims (1)

(57) [Claims] 1. A hot tandem mill in which a looper device for supporting a material to be rolled between rolling stands and a non-contact plate speedometer for detecting the speed of the material to be rolled passing between the rolling stands is provided. The non-contact plate speedometer is connected to the looper device and the looper.
It is installed between the rolling machine and the rolling stand on the downstream side in the traveling direction of the material to be rolled. The looper height of the looper device is measured, and the loop amount between the stands and its differential value are calculated from the measured values for a minute time period. By using the corrected plate speed value by correcting the measured value of the non-contact plate speed meter with the differential value of the loop amount, and using the roll peripheral speed of the upstream rolling stand of the looper device, A method of measuring an advance rate using a non-contact plate speed meter in a hot tandem mill, wherein the advance rate of an outlet side of an upstream rolling stand of a looper device is calculated.