JPH0659484B2 - Method for measuring rolling plate deformation resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention performs sheet rolling between a low speed side work roll and a high speed side work roll, and winds the plate around the high speed side work roll to perform different speed rolling. In this case, it relates to a method for measuring the deformation resistance of a rolled plate online.

[Prior Art] Even when a coil made of the same material is rolled, the hardness varies depending on the coil, so that the deformation resistance of the rolled plate also varies. Therefore, it is necessary to consider the deformation resistance of the rolling plate when setting the roll gap of the work roll of the rolling mill regardless of the constant speed rolling or the differential speed rolling. Thus, conventionally, there is no means for measuring the deformation resistance online, so the work roll gap is set based on the experience and intuition of the worker.

However, in operations that rely on the experience and intuition of workers, there are limits to the labor saving of the rolling line and the plate thickness accuracy of the obtained products. On the other hand, in recent years, in the case of ordinary constant velocity rolling, It has been clarified that the relationship of Since the above relationship has been conventionally known, it has been considered that the deformation resistance K of the rolled plate may be obtained online from the equations (i), (ii), and (iii).

However, P; rolling load t _f; reduction layer _{(h 0 -h 1) R '} ;; rolled plate rear tension Δh of; rolled plate front tension t _b of the time of rolling the flat roll radius R; roll radius B; strip width f (μ); Rolling force function considering friction coefficient μ; C; constant E; Young's modulus ν; Poisson's ratio [Problems to be solved by the invention] However, in the above formula (i), the work roll and the rolling plate are used. It is necessary to calculate the friction coefficient μ between
Is an empirical value, or even if it is obtained from experiments, the rolling force function f (μ) has various formulas, and the results vary depending on which formula is selected. Even if the deformation resistance K is obtained, an accurate value cannot be obtained and reliability may be lost.

In view of the above-mentioned circumstances, the present invention, when performing rolling at a different speed by rolling the rolled plate between the low speed side work roll and the high speed side work roll and performing the different speed rolling around the high speed side work roll, the deformation resistance of the rolled plate is It is intended for online measurement.

[Means for Solving Problems] The present invention provides a rolling method in which a rolling plate is passed between a low speed side work roll and a high speed side work roll and is wound around the high speed side work roll to perform different speed rolling. , The rolling load of the rolled plate and the backward tension of the rolled plate are detected, and the inlet side plate thickness and the outlet side plate thickness of the rolled plate are detected, or the inlet side plate thickness is set and the outlet side plate thickness is detected, and the following formula To obtain the deformation resistance of the rolled sheet online.

[Working] The rolled plate is passed between the low speed side work roll and the high speed side work roll, and is wound around the high speed side work roll for rolling, and based on the detected rolling load and the backward tension of the rolled plate. Based on the detected inlet side thickness and outlet side thickness, or the set inlet side thickness and the detected outlet side thickness, rolling is performed online without obtaining the friction coefficient between the rolling plate and the work roll. The deformation resistance of the plate is required.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, as shown in FIG. 2, the rolling plate S is passed between the low speed side work roll 1 and the high speed side work roll 2 and wound around the high speed side work roll 2 to obtain V ₁ / V ₀ = h ₀ / h ₁ (V ₀
Is the peripheral speed of the low speed side work roll 1, V ₁ is the peripheral speed of the high speed side work roll 2, h ₀ is the entrance side plate thickness of the rolled plate S, and h ₁ is the exit side plate thickness of the rolled plate S. The principle of differential speed rolling will be described with reference to FIGS. 3 and 4.

In FIG. 2, 3 is the deflector roll, N ₁ is the entry neutral point, N ₂ is the exit neutral point, t _b is the backward tension of the rolled material S, t
_f is the forward tension of the rolled material S, and t ₁ is the tension of the rolled material S on the downstream side of the deflector roll 3.

Thus, the projected contact length l during rolling shown in FIG.
From the figure, l ² + (R′−Δh / 2) ² = R ′ ² is obtained. Next, since Delta] h ^2/4 is very small value negligible, Becomes

Further, in the case of different speed rolling, the rolling load does not cause friction hill which occurs in the case of constant speed rolling as shown by the two-dot chain line a in FIG.

Therefore, when the rolled plate S is wound around a work roll and is subjected to different speed rolling, the friction coefficient μ between the low speed side work roll 1 and the rolled plate S and the friction between the high speed side work roll 2 and the rolled plate S. Regardless of the coefficient μ, the rolling load per unit length in the roll axial direction is expressed by the area of the slanted trapezoidal portion in FIG. 4, and if the area of this slanted trapezoidal portion is multiplied by the strip width B, the entire rolling is performed. The load P will be required.

Further, in rolling, when the stress state in the rolled plate S between the rolls 1 and 2 becomes large so as to satisfy the yielding condition, it is deformed, and the plate thickness can be made thin. Is a plane strain state, and the expression of this yield condition is represented by σ ₁ −σ ₂ = K. Where σ ₁ is the maximum principal stress, σ ₂ is the minimum principal stress acting in a direction orthogonal to the maximum principal stress σ ₁ , K is the deformation resistance, and σ ₁ and σ ₂ are the compressive forces. It is expressed as a plus, and when a tensile force acts, it is expressed as a minus.

On the rolling mill entry side, σ ₁ = p ₁ (p ₁ is the rolling load on the rolling mill entry side), σ ₂ = −t _b (t _b is the backward tension of the rolling plate), and On the delivery side, σ ₁ = p ₂ (p ₂ is the rolling load on the delivery side of the rolling mill) and σ ₂ = −t _f (t _f is the forward tension of the rolled plate) are entered into the above-mentioned yield condition equations. , P ₁ + t _b = K, p ₂ + t _f = K, which can be summarized as shown in FIG. 4, where p ₁ = K−t _b on the rolling mill entrance side and p ₂ = K on the rolling mill exit side.
-T _f .

Therefore, the area of the hatched trapezoidal portion in FIG. Therefore, by multiplying this by the plate width B of the rolled plate S, the rolling load P becomes Holds, and from equation (iv) Is required. However, when different speed rolling is performed in the state as shown in FIG. 3, the forward tension t _f cannot be detected, and therefore the deformation resistance K cannot be obtained from the equation (v).

On the other hand, during different speed rolling with the high speed side wound, the neutral point on the high speed side coincides with the gap outlet. From the formula (vi), Becomes Therefore, substituting equation (vii) into equation (v) and rearranging From the equation (viii), the deformation resistance K of the rolled plate s can be measured online without obtaining the friction coefficient μ. In FIG. 3, O'is the work roll 2 on the high speed side.
3, which is the center of FIG. 3, and is the same as that shown in FIG. 2 in FIG. 3 and FIG.

Next, a specific example of the present invention will be described with reference to FIG.
4 is a load detector such as a load cell, 5 is a tension detector for the backward tension t _b of the rolled plate s, 6 is a plate thickness detector on the input side, and 7 is a plate thickness detector on the output side. The signals detected by the tension detector 5 and the plate thickness detectors 6 and 7 can be sent to the calculator 8. Further, to the calculator 8, the strip width B of the rolled strip s,
The radius R of the work rolls 1, 2 and the equations (ii) (iii) (vii) can be set.

At the time of rolling, the strip thickness detector 6 determines the entry strip thickness h ₀ , the strip thickness detector 7 determines the exit strip thickness h ₁ , the tension detector 5 determines the backward tension t _b , and the load detector 4 determines the rolling load P 0.
, Respectively, and the signals are sent to the calculator 8, and the deformation resistance K of the rolled plate s is (ii) (iii) (vi) regardless of the friction coefficient.
It is calculated by the equation i). The deformation resistance K calculated in this way is sent to the arithmetic and control unit, the roll gap correction amount by the deformation resistance K in the downstream rolling mill is calculated, and the roll gap is adjusted based on the calculation result. When obtaining the deformation resistance K, there is no problem even if the neutral points N ₁ and N _{2 in} FIG. ₁ are slightly deviated from the ideal state.

In addition, in the embodiment of the present invention, the case where the entrance side plate thickness is measured has been described, but it is possible to obtain the deformation resistance even if given in advance as a set value, and within the range not departing from the gist of the present invention. Of course, various changes can be made.

EFFECT OF THE INVENTION According to the rolling plate deformation resistance measuring method of the present invention, the rolling plate deformation resistance can be easily and accurately measured online without relying on the experience or intuition of an operator. It is possible to accurately adjust the work roll gap of the rolling mill, and as a result, it is possible to save labor on the rolling line and improve the sheet thickness accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the present invention, FIG. 2 is a general side view showing a state in which a rolled plate is wound and different speed rolling is performed, and FIG. 3 is a projected contact length in the present invention. FIG. 4 is a side view for explaining the principle of determining the rolling force, and FIG. 4 is a side view for explaining the principle of determining the rolling load in the present invention. In the figure, 1 is a low speed side work roll, 2 is a high speed side work roll, 3 is a deflector roll, 4 is a load detector, 6 and 7 are plate thickness detectors, and 8 is a calculator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-22812 (JP, A) JP-A-56-163017 (JP, A) Japan Iron and Steel Institute Joint Research Group Theory and Practice "Japan Iron and Steel Institute (September 1, 1984) PP. 45-47

Claims (1)

[Claims] 1. A rolling method in which a rolling plate is passed between a low speed side work roll and a high speed side work roll and is wound around a high speed side work roll to carry out different speed rolling. Not only the rear tension of the rolled plate but also the inlet side thickness and the outlet side thickness of the rolled plate are detected, or the inlet side thickness is set and the outlet side thickness is detected. A method for measuring the deformation resistance of a rolled plate, which is characterized in that the deformation resistance of the rolled plate is determined online by using the.