JPS631128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for accurately detecting rolling load information used for controlling plate thickness of a rolling mill.

When controlling the plate thickness of a rolling mill using gauge meter thickness, mill hysteresis makes it impossible to obtain accurate gauge meter thickness, which limits the improvement of control accuracy. First, this mill hysteresis will be explained below.

Figures 4a and 4b show the relationship between the rolling reduction amount (horizontal axis) and the rolling load detector output (vertical axis) when rolling load detectors such as load cells are installed on the upper roll side and the lower roll side, respectively. There is. Looking at FIG. 4a, the load output appears lower for the same amount of reduction in the process of decreasing the amount of reduction than in the process of increasing the amount of reduction. This is due to friction between the roll chocks and the mill housing (occurs due to the mill housing side columns bending inward when a rolling load is applied). This is because a part of the force applied from the rolled material side is transmitted to the mill housing side column due to the friction, and the load applied to the detector disposed between the rolling screw and the roll chock is reduced accordingly.

As for the lower roll, as shown in FIG. 4b, on the contrary, the process of reducing the rolling reduction appears higher. This is because the rolling down device is located on the upper roll side, and in the process of reducing the rolling amount, the upward return of the lower roll is affected by friction. Therefore, the rolling load is used to calculate the mill spring amount in calculating the gauge meter thickness, but as shown in Figure 4a and b, the rolling load -
Since the correspondence of the reduction amount is different, an error factor corresponding to this mill hysteresis is included.

It is an object of the present invention to provide a rolling load inspection method that can eliminate rolling load detection errors due to such mill hysteresis, and by extension, gauge meter thickness detection errors.

In the rolling load detection method according to the present invention, a rolling load detector is provided outside the chock of each of the rolls disposed oppositely, the detection signals of both detectors are combined to eliminate the influence of mill hysteresis, and the combined signal is used. The purpose is to detect the rolling load. Hereinafter, the method of the present invention will be specifically explained based on drawings showing its implementation state.

FIG. 1 is a schematic diagram of an apparatus used to carry out the method of the present invention. In the figure, 10 is a mill stand that is subject to rolling down control, and upper and lower rolls 11,
Roll yokes 13 and 14 supporting the mill housing 12 are restrained by the mill housing 15 so as to be able to move up and down. A first load detector 21 is provided between the lowering screw 17 that is raised and lowered by the lowering device 16 and the upper roll chock 13, and a first load detector 21 is provided between the lower roll chock 14 and the lower part of the mill housing 15. A second load detector 22 is provided. A reduction amount detection device 23 is attached to the reduction screw 17. The load detectors 21, 22 and the reduction amount detection device 23 themselves are conventionally known.

The output of the first load detector 21 is transmitted to the first amplifier 3
1 and the output of the second load detector 22 are input to the second amplifier 32 and also to the calculation control section 35. The outputs of the amplifiers 31 and 32 are input to the adder 33, and the output of the adder is input to the arithmetic control circuit 35 via the contact 34a of the switch 34, and to the amplifier 36 via the contact 34b. The arithmetic control circuit 35 controls the amplifier 3 based on input signals from the adder 33 and the like, as will be described later.
Input signals G ₁ and G ₂ to 2 and 36 are calculated and outputted to amplifiers 32 and 36, respectively. Amplifier 3
2 and 36 have an automatic gain adjustment function, and use the input signals G ₁ and G ₂ from the arithmetic control circuit 35 as their gains, respectively. The output of the amplifier 36 is applied to the rolling down device 16 as a detected rolling load. In addition, the output of the reduction amount detection device 23 is given to an arithmetic control circuit 35.

When the contact 34b of the switch 34 is selected, the calculation control section 35 operates in the calibration mode. FIG. 2 is a flowchart showing the control contents of the calculation control unit 35 in this case, and the calculation control unit 35 issues a signal to the reduction device 16 to lower the reduction, drives it, causes the rolls to kiss, and further As the reduction progresses, the output values of the load detectors 21 and 22 are captured and stored in a state in which the output of the reduction amount detection device 23 reaches a predetermined value. Figure 3 A and B show the outputs of the load detectors 21 and 22, respectively, when the reduction amount becomes S ₁ .
Assume that P _1U and P _1L are included. Then, the reduction is further continued, and when a preset reduction amount S ₀ (for example, the lowest limit position) is reached, the reduction is stopped, and then a signal for increasing the reduction is issued. Then, at the position of the aforementioned rolling reduction amount S ₁ , the outputs of the load detectors 21 and 22 are again
Capture P _2U and P _2L and store them. When the lowering position reaches the upper limit, the lowering device 16 is stopped, and a deviation gain and a sum gain are calculated as described later.

The mill hysteresis ΔP _U and ΔP _L of the outputs of the upper and lower load detectors 21 and 22 are calculated according to the following equations (1) and (2).

ΔP _U =P _1U −P _2U ……(1) ΔP _L =P _1L −P _2L ……(2) Therefore, the deviation gain is the gain of the amplifier 32.
It is set as G ₁ and is calculated according to the following formula (3).

G ₁ = -ΔP _U /ΔP _L ...(3) On the other hand, the sum gain is calculated by applying the gain G ₂ to the amplifier 36.
It is set as , and is calculated according to equation (4) below.

G ₂ =P _1U +P _2U +P _1L +P _2L /P _1U +P _2U +G ₁ (P _1L +P _2L )
...(4) The above-mentioned control and calculations are repeated about three times. This is because, in the case of a large gain change, convergence cannot be achieved in one go (see Fig. 2).

After the above processing, the switch 34 is connected to the contact 34.
By switching to the b side, the state becomes the actual measurement mode in which rolling can actually be performed. That is, the outputs from the upper and lower rolling load detectors 21 and 22 (which are now S ₁ and S ₂
) Of S ₁ and S ₂ , the output S ₁ of the former is left as is, and the output S ₂ of the latter is corrected and amplified by the above-mentioned deviation gain G ₁ in the amplifier 32, and is output as S ₂ · G ₁ to the adder. In step 33, the signals are added and synthesized (S ₁ +S ₂ ·G ₁ ).

The output of this adder 33 is normalized by an amplifier 36. That is, multiplied by the sum gain G ₂ (S ₁ +
S ₂ ·G ₁ ) ·G ₂ , the composite load is calculated, and the composite load with almost no mil hysteresis is obtained from the amplifier 36, as shown in FIG. This combined load is applied to the lowering device 16, thereby allowing gauge meter AGC to be performed with high precision.

The method of the present invention is not limited to a screw-down screw as a rolling means, but can also be applied to a machine in which a hydraulic rolling device is provided on the lower roll side, and also to a machine in which the rolls are attached horizontally, such as an edger rolling mill. Applicable. Furthermore, the present invention is not limited to two-high rolling mills.
Needless to say, it can also be applied to a plate rolling mill.

As described above, the present invention provides load detectors on each side of the opposing rolls, and by combining the signals, it is possible to detect a load that effectively eliminates mil hysteresis using a simple principle. As a result, the detection accuracy of the gauge meter thickness is increased, and the plate thickness control accuracy can be increased.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic block diagram showing the implementation state of this method, FIG. 2 is a flowchart of control of the arithmetic control circuit 35 in the calibration mode, and FIG. Figures A to C are explanatory diagrams of the operation, and Figures 4a and 4b are explanatory diagrams of Mil hysteresis. 11, 12...Roll, 16...Reducing device, 2
1, 22...load detector, 23...reduction amount detector, 31, 32, 36...amplifier, 35...arithmetic control circuit.

Claims (1)

[Claims] 1. A rolling load detection method, characterized in that a rolling load detector is provided outside the chock of each of the opposed rolls, the detection signals of both detectors are combined, and the rolling load is detected based on this combined signal.