JPH0465725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a method for controlling camber generated in a rolled material during rolling by a rolling mill.

(B) Prior Art In rolled materials, camber occurs when there is a difference between the left and right roll gaps of the work rolls of the rolling mill during rolling. The conventional camber control method is
The shape or thickness of the rolled material was directly measured to adjust the left and right roll gaps.

In this method, since the camber is dealt with after it actually occurs, the response is slow and the yield decreases.

(c) Problem to be solved by the invention The problem to be solved by the present invention is to measure the camber by measuring the distortion of the housing post of the rolling mill without directly measuring the camber of the rolled material. The objective is to detect and obtain highly responsive camber control.

(d) Means for solving the problem The camber control method for rolled material of the present invention includes installing strain detectors on the inside A and outside B of the housing post on the driving side or driven side of the rolling mill;
Based on the detection signal from the strain detector, the amount of post elongation (L _A ,
L _B ) and the difference in post elongation (ΔL
= L _A - L _B ), determining the occurrence of camber in the rolled material and its direction based on the difference in the amount of elongation (ΔL), and determining the amount of elongation (ΔL)
The above-mentioned problem is solved by correcting the roll gap on the driving side or the driven side so as to make the difference between the two sides zero.

In the method of the present invention, strain detectors are installed inside and outside of the housing posts on the driving side and the driven side, and the average value of the difference in the amount of elongation of each post on the driving side and the driven side is measured. It can be used as a difference in quantity.

(E) Embodiment In the method of the present invention, first, as shown in FIG. 2, strain detectors 4A and 4B are attached to the inside A and outside B of the housing post 11 of the rolling mill 1, respectively. In principle, the strain detectors 4A, 4B may be attached to either the driving side or the driven side of the housing post 11. By attaching them to both sides, the average of both can be calculated, which enables more reliable distortion detection.

The strain detectors 4A, 4B can utilize ordinary strain gauges. Strain gauges detect expansion or contraction of the housing post.

In the normal rolling mill 1, the roll chock (not shown) of the lower roll 22 is fixed to the housing, and the roll chock (not shown) of the upper roll 21 is controlled by AGC (automatic thickness control). It can be adjusted up and down within the housing to do this.

Figures 2B and 3B show the upper and lower rolls 2.
When the roll gap between the driving side (hereinafter referred to as WS) and the driven side (hereinafter referred to as DS) of Nos. 1 and 22 is set correctly, the state in which camber does not occur in the rolled material 3 can be confirmed. show.

2A and 3A or 2C and 3C show the WS of the upper and lower rolls 21 and 22.
This shows a state in which camber occurs in the rolled material 3 when the roll gap with the DS is incorrectly set.

For example, in the case of Figures 2A and 3A, WS
If the roll gap of DS is smaller than that of DS, a force acts on the rolled material 3 in the DS direction (in the direction of arrow 31), and on the contrary, a force acts on the upper roll 21 in the WS direction (in the direction of arrow 211). Force acts.

As a result, the housing post 11 is deflected to WS (double-dashed line), as shown in FIG. 2A. In the rolled material 3, a camber occurs in the DS direction as shown in FIG. 3A due to the difference between the left and right roll gaps.

The same can be said for the cases of FIG. 2C and FIG. 3C. However, in this case everything is reversed from the previous case.

Therefore, the deflection of the housing post 11 is detected as the difference between the expansion and contraction of the inside A and the outside B of the post 11, and the camber is corrected.

For convenience of explanation, Fig. 2A and Fig. 3A are shown below.
The case will be explained using as an example. The output of the strain detector 4A, that is, the amount of post elongation L _A is the post elongation L _R due to rolling and the post elongation (shrinkage) due to deflection.
LD is simply added. That is,
L _A = L _R - L _D (The strain detector outputs elongation (tension) with a plus sign and contraction (compression) with a minus sign.)

On the other hand, the output of the strain detector 4B, that is, the amount of post elongation L _B is simply the sum of the post elongation L _R due to rolling and the post elongation L _D due to deflection. In other words, L _B = L _R + L _D (L _D is the amount of elongation due to the action of tension, so it is positive).

If we find the difference ΔL between post elongation L _A and L _B , we get the following:
It becomes as shown in equation (1).

ΔL=L _A −L _B =(L _R −L _D )−(L _R +L _D )=−2L _D ……(1) As can be seen from equation (1), both distortion detectors 4A and 4B
The difference in output is twice the elongation caused by deflection of the housing post 11, and its sign is based on the strain detector 4A on the inside A. When the sign is positive, the post 11 is on the inside A. Also, when it is negative, the post 11 is deflected toward the outside B.

FIG. 5 shows the relationship between the output of the strain detector and the actual amount of expansion or contraction.

The relationship between the elongation difference ΔL and the camber actually generated in the rolled material can be determined individually in advance using an actual machine. An example is shown in FIG.

When ΔL=0, camber does not occur. Therefore, when ΔL=0, by adjusting the roll gap of WS or DS to make ΔL=0, the camber will be corrected. Therefore,
The relationship between ΔL and the roll gap correction amount to make ΔL=0 may be determined in advance using an actual machine. An example is shown in FIG.

Once ΔL is calculated in this manner, the roll gap correction amount is determined from the relationship shown in FIG. 7, and the camber of the rolled material is corrected by correcting AGC.

The above operating steps are summarized in FIG. 1.

(F) Effects The relationship between the amount of camber and its frequency of occurrence is shown in Figure 4. Figure A shows an example according to the conventional method, and Figure B shows an example according to the method of the present invention. Figure 4 shows the occurrence of camber per 10m of steel strip.

It can be seen that according to the method of the present invention, the amount of camber is reduced.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the camber control method of the present invention. FIG. 2 is a schematic front view of the rolling mill showing the relationship between camber generation and deformation of the housing post of the rolling mill. Figure 3 is a plan view of Figure 2, and each figure A,
B and C correspond to each other. FIG. 4 is a diagram showing the relationship between the amount of camber and its frequency of occurrence, in which Figure A shows the result by the conventional method, and Figure B shows the result by the method of the present invention. FIG. 5 is a graph showing an example of the relationship between the output of the distortion detector and actual distortion. Figure 6 is a graph showing the relationship between camber amount and elongation amount difference (ΔL). Figure 7 is a graph showing the relationship between the amount of elongation (ΔL) and roll gap. 1...Rolling mill, 11...Housing post,
21, 22... Roll, 3... Rolled material, 4A, 4
B...distortion detector, A...inside, B...outside.

Claims (1)

[Scope of Claims] 1. Strain detectors are installed on the inside A and outside B of the housing post on the driving side or driven side of the rolling mill, and the housing post is adjusted based on the detection signal from the strain detector. Calculate the post elongation amount (L _A , L _B ) on each side of the post, calculate the difference in the post elongation amount (ΔL = L _A - L _B ), and perform rolling based on the difference in the elongation amount (ΔL). A camber control method for a rolled material, comprising determining the occurrence and direction of camber in the material, and correcting the roll gap on the driving side or the driven side so as to make the difference in the amount of elongation (ΔL) zero. . 2. Strain detectors are installed inside and outside the housing posts on the drive side and the driven side, and the average value of the difference in the amount of elongation of each post on the drive side and the driven side is used as the difference in the amount of elongation. A method according to claim 1, characterized in that: