JPS6017606B2 - Method for controlling elongation of rolled material - Google Patents

Description

[Detailed Description of the Invention] In rolling thick steel materials such as thick plates, shape hammers, and Hakama steel, it is considered to be one of the extremely difficult techniques to finish the rolled materials to the desired thickness and cross-sectional shape.

The present invention relates to a rolling control method particularly effective for such rolling. For example, in the rolling of thick plates, coins, twill steel, etc., the thickness of the roll is set before rolling so that the material thickness and cross-sectional shape are set to predetermined values, and these dimensions are inspected after rolling. Generally, a method is used to precisely control the amount of reduction of the material.

In order to maintain uniformity in the thickness of the material in the longitudinal direction, for example, a BISRA type (gauge meter type) AGC counterfeiter is installed in the rolling mill, and the rolling reduction amount is controlled according to rolling load fluctuations during rolling. be exposed.

However, in actual rolling operations, the heating temperature and cooling degree may vary slightly depending on the material, or the hardness may vary, so that the rolled product may not be finished with the target thickness or cross-sectional shape.

For this reason, in hot rolling, cold rolling, etc., a method is implemented by monitor AGC in which the thickness and cross-sectional shape of the material are actually measured while the material is being rolled, and the lower layer is corrected one by one. It is difficult to apply the above method to rolled materials, such as nails and steel, whose length is relatively short and whose cross-sectional dimensions are difficult to accurately measure during rolling. The present invention provides rolling control that automatically and accurately controls the thickness and cross-sectional shape to target values by controlling the elongation length of the rolled material without measuring the cross-sectional dimensions of the material during rolling. The purpose is to provide a method.

That is, if the volume (weight) of the rolled material can be measured, once the target cross-sectional area of the product is determined in advance, its total length is also necessarily determined.

Therefore, if the rolling force is adjusted during rolling so that the total length of the material matches its target value, the cross-sectional shape of the product will be controlled as desired. However, the problem here is how to predict the total length of the product during rolling, and the above method becomes possible only by comparing the accurate predicted total length with the target total length. The present invention is based on the measured ratio of the length of material entering the rolling mill during rolling and the corresponding length of material exiting the rolling mill, or the measured ratio of the cross-sections of the unrolled part and the rolled part of the rolled material. Determine the elongation in the rolling direction, use this to predict the length of the material after rolling in the unrolled part, and at the same time measure the length of the material in the completed rolled part to predict the total length of the rolled material at the end of rolling. The gist of this invention is a method for controlling the elongation length of a rolled material, which controls the amount of rolling by a rolling mill so that the total length matches a preset target value.

Hereinafter, the method of the present invention will be explained using examples and referring to the drawings.

The explanatory diagram of FIG. 1 shows an example of the case where this method is implemented in thick plate rolling.

In the figure, 1 is the rolling material, 2 is the rolling mill, 3 is a pulse transmitter connected to the roll shaft of the rolling mill, and 4 and 4' are the positions of appropriate warehouse scales 2 and 2' located rearward from the center of the rolling mill. 5 is a calculation device, and 6 is a lowering drive device. First, the volume obtained from the weight of the material before rolling is divided by the target cross-sectional area of the finished product, and this is stored in the calculation device 5 as the target total length L^.

At the same time, store the evening 2 and evening 2. At the start of rolling, the length of the material at the completed rolling part is measured using the length total 3, and when the tail end of the material reaches the detector 4 (shown at A in FIG. 2), the measured value is sent to the calculation device 5. Store. The above-mentioned material length measurement is performed by the procedure described below.

First, the point at which the tip of the rolled material 1 is bitten by the rolling mill 2 is measured using a load cell (not shown) installed in the rolling mill 2.
Detected by. Next, the number of pulses P from the pulse transmitter connected to the roll shaft after the biting time is measured, and the length of the material is determined using the following formula '11. So, :U・
P.・・・． ...'1l However: Circumference ratio D: Roll diameter n: Number of pulses generated from the pulse transmitter per roll rotation P: Number of pulses from the point of biting As rolling progresses further, the tail end of the material reaches detector 4 ′ (as shown in B in Fig. 2), the material length of the completed rolling part is closed again.
, is determined and stored using the method described above, and the following calculation is performed from this.

First, the first equation is calculated to obtain the predicted material length after rolling of the unrolled portion at the time when the material tail machine reaches the detector 4'.

Yu-2=So'2-Kozo-Maki--------■ In the above formula, (So', 1Z,)/kuso2 - and '2) means that the total material tail is from detector 4 to 4' Rolling is expressed as the ratio of the length of material that entered the rolling mill 2 during the rolling process (Y21〆'2) and the corresponding length of material that came out of the rolling mill (So', Iso,). This is the elongation of the material, and the product of this multiplied by the material length of the unrolled part '2 is nothing but the predicted material length after rolling.Continuously, the total length L of the rolled material after rolling, which is predicted at this point, is calculated as Calculate from equation 3.

L=So'. 10"2...[3] Here, the predicted total length L is compared with the target total length L^ stored in advance, and if both agree, rolling is continued.

When the two do not match, a rolling correction amount ΔS is calculated from the deviation ΔL using the fourth equation, and this is output to the rolling drive device 6 to correct the rolling straight. △s; Kansan・Dan・△L
...'41 In the above formula, M is the mill stiffness coefficient, Q is the plasticity coefficient, and h^ is the target plate thickness.

When the predicted total length L is smaller than the target total length, the above modified △
The amount of rolling is increased according to S to make the total length after finishing the rolling match the target value. On the other hand, when L is larger than L^, the reduction amount is reduced to suppress elongation. In addition, in a rolling mill in which a gauge meter type AGC device is operated, it is sufficient to simply add the correction amount Δh shown by the following equation 5 instead of equation 4 to the plate thickness deviation value of the AGC circuit.

Δh: Stem-ΔL...---'51 The method of the present invention can also be carried out when the cross-sectional dimensions of the material can be measured relatively accurately during rolling of thick plates, steel plates, etc.

For example, Shinko rolling will be described below as an example. Third
The figure is an explanatory diagram corresponding to the above-mentioned FIG.

Reference numerals 7 and 7 are cross-sectional dimension meters that measure the cross-sectional dimensions of the material before and after the rolling mill. Calculate and find.

Prior to rolling, the target total length L^ of the finished product and the length 2 are stored in the calculation device 5.

At the time when the tail end of the material passes the detector 4, the material length of the rolled part is measured, and at the same time, the cross-sectional lines S, S2 of the rolled part and the unrolled part are measured with the aforementioned cross-sectional dimension meter 7. Let's move on to calculations. The calculations are performed sequentially using the following equations 6 to 8, and finally, the shoring correction amount ΔS is determined and outputted to the rolling drive bag straight 6. Buddha-minded...State L=K. 〆r2・ ...{71△S=
f・△L...'81 S2/S in the above-mentioned formula 6 is a measurement ratio that corresponds to the elongation of the rolled material mentioned above, and is also a measurement ratio that corresponds to the elongation of the rolled material as described above. In the case, S2/S is the plate thickness ratio before and after rolling ~/h
, can be approximated by .

Note that f in the 8th equation is mill stiffness, plasticity coefficient, S, or h,
, L^. The basic embodiment of this method has been described above, but in addition to this, it is possible to increase the control accuracy by adding a tail end detector and sequentially correcting the amount of reduction. Various implementations are possible without departing from the gist of the present invention, such as performing continuous control using this measuring roll.

In this way, the present invention controls the elongation of the rolled material while predicting the finished total length of the material during rolling, so it is possible to ensure the target total length of the product. Because it can be finished into a specific shape, it can be used to roll thick plates, shaped steel, steel bars, etc. whose cross-sectional dimensions are difficult to measure during rolling, and is highly effective in improving their quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the case where the present invention is implemented in thick plate rolling, and FIG. 2 is an explanatory diagram showing the progress of the rolled material in FIG. 1. FIG. 3 is a diagram illustrating another implementation of the present invention. Symbols in the diagram,
DESCRIPTION OF SYMBOLS 1...Rolled material, 2...Rolling machine, 3...Pulse transmitter, 4, 4'...Tail end detector, 5...Computational equipment, 6
...Pupillary drive unit, 7...Cross-sectional dimension meter. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. Predicting the length of the material after rolling of the unrolled portion from the measurement ratio of the length of the material entering the rolling mill during rolling and the corresponding length of the material exiting the rolling mill, and simultaneously predicting the length of the material after rolling of the rolled portion. A method for controlling the elongation length of a rolled material, comprising: measuring the length of the material and controlling the amount of reduction of a rolling mill so that the predicted total length of the rolled material at the end of rolling matches a preset target value. 2. During rolling, the length of the material after rolling of the unrolled portion is predicted from the measurement ratio of the cross-sectional area of the unrolled portion and the rolled portion of the rolled material, and at the same time the material length of the rolled portion of the rolled material is actually measured and the rolling of the rolled material is completed. 1. A method for controlling the elongation length of a rolled material, the method comprising controlling the amount of reduction of a rolling mill so that the predicted total length at a time matches a preset target value.