JPH0557323A - Method for controlling steel plate edge heating device - Google Patents

Abstract

PURPOSE:To provide a method for controlling a steel plate edge heating device in a rolling process to secure the uniform finish temperature for a rolled stock. CONSTITUTION:In a hot rolling line, an amount of camber of the rolled stock 1 is detected by a camber detector 7 arranged on the upstream side of the steel plate edge heating device 9. An amount of gap between upper and lower inductors 2, 3 is determined based on the detected value of the camber. The gap conforming to the amount of camber of each rolled stock can be set to keep the optimum efficiency at all times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate edge heating apparatus in a hot rolling process used for eliminating uneven temperature in the width direction of a rolled material and for ensuring a uniform finishing temperature of the rolled material. Control method

[0002]

2. Description of the Related Art Conventionally, the most widely used type of steel sheet edge heating device is an induction heating type heating device shown in FIG. 2, in which the magnetic flux generated between the upper and lower inductors 2 and 3 is It utilizes Joule heat due to eddy currents generated on the surface of the rolled material 1 when the rolled material 1 passes through. Due to its structure, the smaller the gap between the upper and lower inductors, the larger the heat input amount and the more efficient it is. Therefore, it is required to set the gap amount as small as possible.

[0003]

However, there is a warp portion called a warp or a warp at the front and rear ends of the steel sheet in the hot process, and in the steel sheet edge heating device, this warp portion causes equipment damage. There is a risk of causing Therefore, it is necessary to set a large gap between the upper and lower inductors at the leading and trailing edges of the steel sheet, pass the warped portion at the leading and trailing edges of the steel sheet, and then reset the gap to the minimum amount to avoid danger. .. As described above, conventionally, the maximum value of the amount of warpage that is expected to occur is set as the gap setting amount between the upper and lower inductors, and the control method is mainly for avoiding the risk of equipment damage.

However, although such conventional control methods can avoid equipment damage, there is a large loss in terms of efficiency and it cannot be said to be a sufficient measure from the viewpoint of energy saving.

[0005]

The gist of the present invention is to control the vertical gap position of a steel sheet edge heating device on the basis of a detected value from a warp detector arranged upstream of the steel plate edge heating device in a hot rolling line. Is a method for controlling a steel sheet edge heating device.

[0006]

The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the control configuration. Regarding the rolled material 1 transmitted from the warp detector 7 via the controller 11 for the detector, the warp amount of the front and rear ends of the rolled material 1 conveyed by the table roller 4 and the upper process computer 8 are transmitted. From the information, the gap amount between the upper and lower inductors 2 and 3 of the steel plate edge heating device 9 is calculated by the calculation device 10, and the edge heating device control device 1 is calculated.
The setting position of the gap is controlled via 2.

FIG. 3 shows each positional relationship for obtaining the warp amount, and FIG. 4 shows a detection image of an image sensor type detector. It is shown that the pixel has n divisions in the X direction and m divisions in the Y direction. A low position (Yb) and a high position (Ya) are set as reference points in the height direction (Y direction).

After the warp detector is fixed, the measured height values of the low position and the high position are obtained at a position ± D from the line center. The values obtained from the above measurements are set as in Equation 1.

[0010]

[Formula 1] X: Distance from warp detector tip to line center Xn = X-D: Distance from warp detector to reference point 2 on the side closer to the warp detector Xf = X + D: Warp detector to warp detector To the reference point 1 on the side farther away from the side Ln: Actual measurement value of height of low position Yb at Xn Hn: Actual measurement value of height of high position Ya at Xn Lf: Actual measurement value of height of low position Yb at Xf Hf : Actual measured height of high position Ya at Xf

When a warp measurement is performed on a steel plate having a width W, is it measured at an end close to the X-W / 2 warp detector?
Or, it is either the end farther than the warp detector of X + W / 2.

The height L of the low position Yb and the high position Ya at the points X-W / 2 and X + W / 2.
n ′, Hn ′, Lf ′, and Hf ′ are represented by the calculation formula number 2.

[0013]

Ln ′ = Ln + (Lf−Ln) × (D−W / 2) ÷ (2 × D) Hn ′ = Hn + (Hf−Hn) × (D−W / 2) ÷ (2 × D) Lf ′ = Ln + (Lf−Ln) × (D + W / 2) ÷ (2 × D) Hf ′ = Hn + (Hf−Hn) × (D + W / 2) ÷ (2 × D)

Here, the upper end height (upward warp position) of the steel plate is Y, and the measurement coordinate position at that time is P.

When the amount of warp on the side closer to the warp detector is detected, the equation 3 is obtained.

[0016]

## EQU00003 ## Y = Hn '-(Hn'-Ln'). Times. (P-Ya) / Yb ...

When the warp detector detects the warp amount on the far side, the following equation 4 is obtained.

[0018]

## EQU00004 ## Y = Hf '-(Hf'-Lf'). Times. (P-Ya) / Yb ...

When the material height is larger than a certain value (PP, YY), the one closer to the warp detector is detected, and when the material height is smaller than the warp detector, the one farther than the warp detector is detected. A certain value (P
P, YY) is given by the equation,

[0020]

## EQU5 ## PP = (Hf'-Hn ') / ((Hf'-Lf')-(Hn'-Ln ')) * Yb + Ya YY = (Hn' * (Hf'-Lf ')-Hf' * (Hn'-Ln ')) / ((Hf'-Lf')-(Hn'-Ln '))

Therefore, the formula is used when P is smaller than PP (when the material height is higher than YY), and when P is larger than PP (when the material height is lower than YY). It is possible to calculate the amount of warpage. The amount of warp can also be calculated by the same method.

[0022]

EXAMPLES Next, the control according to the present invention will be specifically described with reference to examples.

FIG. 5 shows the distribution of the amount of warp that can occur in the line as the knowledge so far. It can be seen that the maximum is 30 mm or more. On the other hand, FIG. 6 shows changes in the amount of warpage from the front end to the rear end of the material detected by this method. If the conventional method is adopted, the gap between inductors is
There is no choice but to set it to 0 mm, and it is inevitable that efficiency will drop significantly. However, by setting the gap according to the amount of warpage for each plate according to the present invention, it was possible to always maintain optimum efficiency.

[0024]

As described above, according to the present invention, since the efficiency can be always kept optimum, the amount of energy used can be suppressed to the minimum necessary amount without being wasted. Further, even when an abnormal warp occurs, it is possible to obtain the effect that the steel sheet edge heating device can be evacuated urgently.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device for carrying out the present invention.

FIG. 2 is a side view of a steel plate edge heating device.

FIG. 3 is a diagram showing each positional relationship for obtaining a warp amount.

FIG. 4 is a diagram showing a detection image screen of the warp detector.

FIG. 5 is a diagram showing a warp amount distribution on a real line.

FIG. 6 is a diagram showing a transition of a warp amount detected by using a warp detector from the front end to the rear end of a rolled material.

[Explanation of symbols]

 1 rolled material 2 upper inductor 3 lower inductor 4 table roller 5 upper inductor gap adjusting device 6 lower inductor gap adjusting device 7 warp detector 8 upper process computer 9 steel plate edge heating device 10 arithmetic unit 11 controller for detector 12 edge heating Device control device

Claims (1)

[Claims] 1. In a hot rolling line, the vertical gap position control of the steel plate edge heating device is performed based on a detection value from a warp detector arranged upstream of the steel plate edge heating device. Device control method.