JPH0365610A - Method and apparatus for measuring shape on-line - Google Patents

Abstract

PURPOSE:To enable accurate measurement of the shape of a steel strip on-line by adding up the differential expansion rate of a latent shape constituent of the steel strip and the differential expansion rate of an actual shape constituent thereof. CONSTITUTION:First, in a steel strip width direction tensile-force distribution detecting mechanism 2, a cylindrical detection element 21 having a prescribed length is arranged in a plurality of layers in the axial direction and rollers 7 are so formed as to support the detection elements 21 slidably mutually in the axial and radial directions. The rollers 7 being brought into pressure contact with a steel strip 1, the differential expansion rate DELTAepsilon1 of a latent shape constituent of the steel strip 1 is determined on the basis of the distribution of a tensile force of the steel strip applied to each detection element 21. In a steel strip width direction surface displacement detecting mechanism 3, subsequently, the displacement of the surface of the steel strip is detected on the basis of measuring signals from a plurality of displacement gages 31 disposed oppositely to the detection elements 21 with a prescribed gap therefrom, and the differential expansion rate DELTAepsilon2 of an actual shape constituent of the steel strip 1 is determined on the basis of the displacement. By adding up the differential expansion rates (DELTAepsilon1 + DELTAepsilon2) by an arithmetic unit 4, the shape in the width direction of the steel strip 1 in the longitudinal direction can be decided.

Description

DETAILED DESCRIPTION OF THE INVENTION G) Industrial Application Field The present invention relates to a method and apparatus for measuring the shape of a steel strip in a steel strip rolling line.

(b) Conventional technology As a method for online measuring the shape of a rolled material such as a thin steel strip, when tension is applied to the rolled material, the tension in the rolled material is generated in the width direction in response to the longitudinal elongation of the rolled material. It is common to measure the distribution.

Among these methods, a method is often used in which a plurality of detection elements divided in one width direction are arranged and the component force of the tension of the rolled material applied to each detection element is measured. In particular, online shape measurement has become mainstream in cold rolling.

On the other hand, there is a method in which the surface displacement of the steel strip is measured with no tension applied to the steel strip, and the shape is determined by determining the wave height, wavelength, and length along the surface. This measurement method has been put to practical use as a shape measurement method in an offline or online no-tension state (for example, the state 1 in which the tip is bitten by the down coiler on the exit side of hot rolling).

However, there are various problems in actual online plate shape measurement. ! First, the former method of measuring tension distribution is based on the premise that the difference in elongation in the width direction of the steel strip due to the addition of tension results in the distribution of tension. However, when the elongation difference is large, there is a limit to the tension that can be applied, especially in hot-rolled materials, so the elongation difference and tension distribution may not be in a proportional relationship. In other words, there is a state in which the actual shape remains even if tension is applied. In such cases, in areas where the difference in elongation appears as a shape.

Regardless of the magnitude of the elongation difference, a problem arises in that it is not detected as a tension distribution.

On the other hand, the latter steel strip surface displacement measurement method is a method of measuring an actual shape, and is therefore not suitable for online shape measurement where the shape becomes latent due to the application of tension. Even if the steel strip is used online and under no tension, for example at the exit side of a hot rolling finishing stand, where the tip of the steel strip is caught in the down coiler, the This is because disturbances such as band flapping are likely to occur.

Highly accurate shape measurement is difficult.

←→Problem to be Solved by the Invention The problem to be solved by the present invention is to provide a method and apparatus for accurately measuring the shape of a steel strip online.

B) Means for Solving the Problems The online shape measuring method of the present invention includes applying longitudinal tension to a steel strip online, measuring the widthwise distribution of the steel strip tension, and measuring the widthwise distribution based on the widthwise distribution. Determining the elongation difference Δε1 of the latent shape component of the steel strip, measuring the width direction distribution of the surface displacement of the steel strip, and determining the elongation difference Δε of the actual shape component of the steel strip based on the surface displacement distribution. That is, adding up the above elongation difference rate (Δε1 + Δε2)
The above problem is solved by means of determining the shape in the width direction of the steel strip to be buttoned at an arbitrary position in the longitudinal direction of the steel strip.

The online shape measuring device of the present invention has a plurality of layers of cylindrical detection elements each having a predetermined length arranged in the axial direction, and each of the detection elements is slidably supported relative to each other in the axial and radial directions to form a roller. , a mechanism that presses the roller against the steel strip and detects a component of the steel strip tension applied to each of the detection elements, and a plurality of displacement gauges that are arranged facing each of the detection elements at a predetermined interval. , a mechanism for detecting the displacement of the surface of the steel strip based on the measurement signals from each of the displacement meters, and a computing unit for determining the shape of the steel strip by adding up the detection signals from both of the mechanisms. , which solves the above problems.

(e) Effect The tension distribution (latent shape) and surface change (actual shape) of a steel strip are measured using the method of the present invention. Elongation difference rate Δε1 for the potential shape obtained from the tension distribution using equation (4) described later
and the difference rate of elongation Δ for the actual shape obtained from the length along the steel strip surface obtained by line integration using the actual shape waveform data.
By overlapping ε2, the overall shape of the steel strip is determined.

In the method of measuring the widthwise distribution of steel strip tension, by applying tension to the steel strip, the widthwise distribution of the difference rate Δε1 of the steel strip can be replaced by the tension distribution. However, this method is not suitable for materials that cannot be subjected to large tension, such as hot materials, or materials that have poor flatness and may leave apparent shape defects. On the other hand, the method of measuring the actual shape is suitable for a measurement object having a large elongation difference Δε2. Since the surface displacement of the steel strip is measured, it is desirable to perform the measurement in a place where the vertical movement is as small as possible even when the object to be measured is stopped or online (Fig. 7).

Therefore, in order to measure the shape of a steel strip online, the present invention proposes a method in which tension is applied using a split roll detection element and the latent shape of the steel strip is measured as a tension distribution, and a method in which the latent shape of the steel strip is measured as a tension distribution. By using this method in combination with the method of measuring the actual shape of the steel strip, the shape of the steel strip can be accurately measured over a wide range.

(F) Embodiment An embodiment of the online shape measuring method and apparatus of the present invention will be described with reference to FIG. 1 and FIG.

First, in the online shape measuring method of the present invention, a longitudinal tension T is applied to the steel strip 1 online. This tension T is between the staff 1 of the rolling mill row, between the final stand and the dhow/carp 2,
The casing is generated between the priddle rolls, etc.

The tension distribution in the width direction of the steel strip 1 is measured, and the elongation difference rate Δε1 of the latent shape component of the steel strip 1 is determined based on this tension distribution. The widthwise distribution of tension is detected by a mechanism 2, which will be described later (FIG. 2).

The surface displacement distribution in the width direction of the steel strip 1 is measured, and the elongation difference rate Δε of the actual shape component of the steel strip 1 is determined based on this displacement. The widthwise distribution of this surface displacement is.

It is detected by a mechanism 3 which will be described later (FIG. 2).

By adding up the elongation difference rates (Δε1+Δε,),
The shape in the width direction of the steel strip 1 to be applied at an arbitrary position in the longitudinal direction of the steel strip 1 is determined. This summation is performed by an arithmetic unit 4, which will be described later. By performing this measurement at every predetermined pitch along the longitudinal direction of the steel strip 1, the required length or overall shape of the steel strip 1 can be grasped.

Next, an online shape measuring device for implementing the above method is made up of a steel strip width direction tension distribution detection mechanism 2, a steel strip width direction surface displacement detection mechanism 3, and a computing unit 4.

The steel strip width direction tension distribution detection mechanism 2 has a plurality of cylindrical detection elements 21 having a predetermined length arranged in a plurality of layers in the axial direction, and each of the detection elements 21 is slidable relative to each other in the axial direction and radial direction. The support forms a roller, and the roller is brought into pressure contact with the steel strip 1.

The component force of the steel strip tension applied to each detection element 21 is detected.

Steel strip width direction surface displacement detection mechanism Roha, each detection element 2
1 is provided with a plurality of displacement meters 31 arranged facing each other at a predetermined interval, and the displacement of the surface of the steel strip is detected based on the measurement signal from each displacement meter 31.

The computing unit 4 adds up the detection signals from both the mechanisms 2 and 5, and determines the shape of the steel strip 1.

As shown in FIG. 6, each detection element 21 is rotatably and radially movably supported by a row 27 supported by a load cell 6 that detects a load.

As shown in FIG. 3, the shape detection roller 2 is composed of a plurality of cylindrical detection elements width 1 of a predetermined length, as shown in FIGS. 4 and 5.

The load F applied to one detection element 21 is as follows (1)
Expressed by the formula.

F=2T−8inθ −−−−(11T=σ11w1
1t...(2) However.

σ: Tensile stress W: Detection element width t: Steel plate thickness θ: When wrapping a rusted steel plate, if the Young's modulus of the square steel strip is E, the elongation rate ε due to tension is expressed by the following formula (3): σ=ε・E...(3) Therefore, from the formula (11, +21, +31), the following formula (4) is obtained.

According to equation (4), the tension component force F applied to each element 21 is
By finding i, the elongation rate εi can be found. From there, the elongation rate distribution can be determined. However, the tensile stress σ can only be applied in the cold state of 30 Kti/w2 and in the hot state of about 2 Kg1-2. Therefore, as shown in equation 13), the steepness in the cold is 2.4% (E = 2. I x 10'Kg/m"
) Hot and steepness 0.9'J= CB= 1. Ox 1
0 Kf/rm" at 1000°C), it is possible to measure only up to a certain level of elongation.

In reality, there are shapes with a larger elongation distribution, so in that case the actual shape remains even if tension is applied. Therefore, the remaining portion may be measured using a method that measures the actual shape. At that time, if the displacement position 31 is used to sandwich the steel strip 1 to be measured and measure the displacement of the button on the opposite side of the detection element 21, the steel strip 1 can be pressed even during online running.
Accurate measurements can be made without flapping, and
Since the presence or absence of an actual shape can be determined from the displacement of the steel strip at the position corresponding to each detection element 21, more accurate and comprehensive shape detection is possible.

A steel strip having a shape as shown in FIGS. 9 and 10 is
FIG. 11 shows the results of precision measurement of the actual shape in an off-line state using a shape measuring device such as that shown in FIG. Figure 11 shows the following.

■ The shape determined from the tension distribution does not appear flat even when the middle elongated part is under tension, so it does not appear as a tension difference, so the inner part is less visible no matter what shape it actually is.

■ In online shape measurement using the displacement meter 51, a portion of the mid-elongated shape is latent in the ear wave portion, so the actual shape is generally smaller.

■ The shape obtained by measuring both the tension distribution and the actual shape using the method of the present invention is in good agreement with the shape precisely measured offline in the no-tension state. It can be seen that the band shape can be measured correctly.

The elongation difference rate Δε in FIG. 11 is determined in a linear manner using the minimum elongation L as the standard in the elongation distribution in one width direction, as shown in FIG.

First, the length Li (1=1-n) of the steel plate between the projected length Lo at each position of n points in the width direction is determined. next.

It is determined as the elongation rate of the steel plate with respect to the projected length Lo clicked at each point. Next, the smallest one among εi.

In other words, find the one with the least elongation and find it! min
= (Lmin - Lo)/Lo. lastly,
The difference Δεi in elongation at each point in the width direction is determined using εmin as a reference. That is, Δεi=εi−εm1n= (Li
-Lmin)/L.

The reason why Δε obtained in this manner is used is to eliminate the influence of the ridges of the entire steel plate in the elongation rate ε.

(g) Effects According to the present invention, a wide range of steel strip shapes can be accurately measured,
In addition, even online, there is no flapping of the steel strip, making it possible to measure the actual shape.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an apparatus for carrying out the method of the invention. FIG. 2 is a detailed explanatory diagram of the present invention. FIG. 3 is a perspective view of a steel strip width direction surface displacement detection mechanism used in the present invention. 4. FIGS. 1 and 5 are explanatory diagrams of the operation of the detection element. FIG. 6 is an explanatory diagram of the support mechanism for the detection element. FIG. 7 is a graph showing the relationship between the actual shape and latent shape of the steel strip. FIG. 8 is an explanatory diagram of the elongation difference rate. FIG. 9 is an explanatory diagram of the surface shape of the steel strip. FIG. 10 is a schematic diagram of a steel strip shape created based on off-line measurement data. FIG. 11 is a graph showing the measurement results of the steel strip shape. 1: Steel strip 2: Steel strip width direction tension distribution detection mechanism 5: Steel strip width direction surface displacement detection mechanism 21: Detection element 31 = displacement meter.

Claims (1)

[Claims] 1. Applying longitudinal tension to the steel strip online, measuring the widthwise distribution of the steel strip tension, and determining the elongation difference rate of the latent shape component of the steel strip based on the widthwise distribution. determining Δε_1, measuring the widthwise distribution of the steel strip surface displacement, determining the elongation difference rate Δε_2 of the actual shape component of the steel strip based on the surface displacement distribution, and summing the elongation difference rates ( Δε_1+Δε_2) An online shape measuring method comprising determining the shape in the width direction of the steel strip at an arbitrary position in the longitudinal direction of the steel strip. 2. A roller is formed by arranging a plurality of cylindrical detection elements having a predetermined length in the axial direction and supporting each of the detection elements so as to be slidable relative to each other in the axial and radial directions, and the roller is attached to a steel strip. a mechanism for detecting the component force of the steel strip tension applied to each of the detection elements; and a plurality of displacement gauges disposed facing each of the detection elements at a predetermined interval; An online shape measuring device comprising: a mechanism for detecting the displacement of the surface of a steel strip based on measurement signals from the measuring device; and a computing unit for determining the shape of the steel strip by adding up the detection signals from both of the mechanisms.