JPH0116205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting tension between stands of a rolled material during continuous rolling.

A conventional inter-stand tension detection method includes a method of determining front tension from rolling torque, rolling force, and rear tension in each stand. This will be explained with reference to the continuous rolling apparatus shown in FIG. In Fig. 1, 1 is the material to be rolled, 2 is the i-th stand, and 3 is the (i-th
+1) stand, T _i-1 is the i-th stand rear tension, T _i is the i-th stand front tension, G _i is the rolling torque of the i-th stand, and P _i is the rolling force of the i-th stand. At this time, the rolling torque G _i is expressed by the following formula.

G _i =a _i・P _i +b _i・T _i-1 −c _i・T _i ………(1) In equation (1), a _i , b _i , and c _i are constants determined by one rolling condition. Here, a _i , b _i , and c _i will be referred to as a torque arm, a rear tension torque arm, and a front tension torque arm, respectively. The forward tension is determined by equation (1).
T _i can be calculated as T _i =(a _i ·P _i −G _i +b _i ·T _i-1 )/c _i (2). In equation (2), rolling force P _i ,
The rolling torque G _i can be directly detected, and the backward tension T _i-1
can be determined by sequentially determining the inter-stand tension starting from the upstream.

On the other hand, a _i , b _i , and c _i are constants determined by one rolling condition, and conventionally, b _i = c _i = R _i (3) R _i is the roll radius of the i-th stand. , and for the torque arm a _i , the fluctuation during rolling is a _i = a ^L _i +Δa _i ......(4), and the reference torque arm a ^L _i is set when the front tension T _i = 0, that is, when the rolled Immediately before the material 1 is bitten by the (i-1)th stand 3, it is calculated as a ^L _i =(G ^L _i −R _i −T ^L _i-1 )/P _i ^L (5). This timing is called lock-on timing. In equation (5), the suffix "L" means the value at lock-on. The amount of torque arm fluctuation Δa _i after lock-on is obtained as Δa _i =Δa _i (ΔH _i , Δh _i , ΔR _i ′, Δk _ni , ΔT _i-1 , ΔT _i ) (6). However, in equation (6), ΔH _i , Δh _i ,
ΔR _i ′, Δk _ni , ΔT _i-1 and ΔT _i are the entry side plate thickness, respectively.
These are the amount of variation in the exit plate thickness, flat roll diameter, average deformation resistance, rear tension, and front tension. As mentioned above, in order to obtain the tension T _i between conventional stands, it is assumed that the rear tension torque arm b _i and the front tension torque arm c _i are constant and approximately equal to the roll radius R _i , and only the torque arm is set under the conditions during rolling. The forward tension was determined using equation (2) by changing it during rolling according to the fluctuations in equations (4) and (6).

However, as a result of rolling theory analysis and testing, it has been found that the conventional method described above causes forward tension errors. That is, according to the analysis of the rolling theoretical model regarding rolling torque and rolling force, G _i a _i (H _i , h _i , R _i ′)・P _i +b _i (H _i , h _i , R _i ′)・T _i
-1 −c _i (H _i , h _i , R _i ′)・T _i ......(7) Therefore, the tension torque arm b _i , c _i is the inlet side plate thickness H _i , the outlet side plate thickness h _i , and the flat roll diameter It turns out that it is a function of R _i ′. That is, the tension torque arms b _i and c _i were conventionally considered to be constant as the roll radius, but in order to improve the tension detection accuracy, it is necessary to change them as the rolling conditions change, similar to the torque arms.

An object of the present invention is to improve the detection accuracy in tension detection in which forward tension is detected based on the above-mentioned arithmetic expression.

Next, one apparatus configuration for implementing the present invention is shown in FIG. 2, and an embodiment of the present invention will be described with reference to FIG. In equation (7), the flat roll diameter R _i ′ and the rolling force P _i ,
The relationship between the entrance and exit side plate thicknesses H _i and h _i is known in advance as R _i ′ = R _i ′ (P _i , H _i , h _i ) (8), so b _i = b _i (H _i , h _i , P _i ) ......(9) c _i = c _i (H _i , h _i , P _i ) ......(10) and the front and rear tension torque arms are determined by the input and exit plate thicknesses and rolling force. You can ask for it. As mentioned above, the conventional method of locking on the torque arm and calculating the amount of torque arm variation Δa _i after locking on as shown in equation (6) can be applied to the front and rear tension torque arms b _i and c _i as well. It can be found by the formula.

Δb _i = Δb _i (ΔH _i , Δh _i , ΔP _i , ΔS _i , ………) ………(11) Δc _i = Δc _i (ΔH i , Δh _i , ΔP _{i ,} ΔS _i , ………) ......(12) Therefore, using the input side plate thickness H _i , exit side plate thickness h _i , and rolling force P _i as input, the torque arm calculation device 5 calculates (4)
The torque arm during rolling is calculated using equations (5) and (6), and the rear tension torque arm calculation device 6 calculates equations (8) and (9) or (9).
The rear tension torque arm during rolling is calculated based on the formula and (11), and the front tension torque arm calculation device 7 calculates the rear tension torque arm during rolling.
The front tension torque arm during rolling is calculated based on equations (8) and (10) or equations (10) and (12). Using the obtained torque arm and rear front tension torque arm, the front tension during rolling is determined by the front tension calculating device 4 based on equation (2). It should be noted that, as is widely known, there is a relationship between the roll gap S, the exit side plate thickness, and the rolling force of h=S+F/M, M; Mill constant, so the exit side plate thickness h is determined while taking this relationship into consideration. It is clear that the same result can be obtained by using the low gap S instead of _i .

As described above, in the present invention, the rolling stand i
Find the torque arm a _i , rear tension arm b _i and front tension arm c _i after locking on during rolling.
Since the tension is detected using a predetermined calculation formula based on this, the forward tension detection accuracy is significantly higher than the conventional method in which a _i , b _{i ,} and c _i are fixed after lock-on.

[Brief explanation of drawings]

Figure 1 shows the rear tension at rolling stand 2.
T _i-1 , forward tension T _i , rolling torque G _i and rolling force P _i
FIG. 2 is a block diagram showing the configuration of one device used to implement the present invention. 1: Rolled material, 2, 3: Rolling stand, 4: Front tension calculation device, 5: Torque arm calculation device, 6:
Rear tension torque arm calculation device, 7: Front tension torque arm calculation device.

Claims (1)

[Claims] 1 At rolling stand i, rolling torque Gi and
In continuous rolling, the front tension Ti is calculated using a predetermined calculation formula based on the product of torque arm ai and rolling force Pi, the product of rear tension torque arm bi and rear tension Ti _-1 , and front tension torque arm ci. When detecting tension between stands, the torque arm AI, front tension torque arm ci, and rear tension torque arm bi are changed according to changes in the inlet side plate thickness, outlet side plate thickness, and rolling force. A method for detecting tension between stands in continuous rolling.