JP2003117604A - Method and apparatus for measuring shape of camber of rolled metallic strip and rolling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology for measuring the shape of a camber generated on a hot-rolled steel strip accurately and at a low cost during the hot-rolled steel strip is rolled. SOLUTION: This rolling equipment is a rolling equipment 3 for the hot-rolled steel strip 2 which is provided with a roughing mill 4 for rolling the hot-rolled steel strip 2, an apparatus 5 for measuring the position in the width direction which is installed in the position where it is separated by the distance L (mm) which is determined by L>=((5,230W-2,687,500)/(1.57×10<-6> W))<1/2> from the roughing mill 4 and a camber calculating device 6 for calculating the shape of the hot-rolled steel strip 2 on the basis of the output value of the apparatus 5 for measuring the position in the width direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a camber shape of a rolled metal strip, a device for measuring a camber shape, and a rolling apparatus. For example, a camber shape generated when a hot rolled steel strip is manufactured by rolling is hot rolled. The present invention relates to a method for measuring a camber shape of a hot-rolled steel strip, a camber shape measurement device, and a rolling device that can be accurately measured during rolling of the steel strip.

[0002]

2. Description of the Related Art When a metal strip is manufactured by rolling (a "hot rolled steel strip" will be taken as an example in the following description), an error caused in the initial setting of a roll gap in the latest rolling mill is introduced into the rolling mill. Rolling is caused by various factors such as the difference in sheet thickness (wedges) existing at both widthwise ends of the material to be rolled, and the deviation of deformation resistance based on the temperature difference occurring at both widthwise ends of the material to be rolled. On the exit side of the machine, uneven elongation may occur on both widthwise ends of the hot-rolled steel strip. If this uneven elongation occurs on both widthwise ends of the hot-rolled steel strip,
The hot-rolled steel strip running on the exit side of the rolling mill has a shape (referred to as “camber shape” in the present specification) which is entirely curved in a horizontal plane around the rolling mill in the horizontal plane. In order to stabilize the system during rolling of the hot-rolled steel strip, it is necessary to quickly respond to the generated camber shape so that the center line of the hot-rolled steel strip and the center of the pass line coincide with each other as much as possible. It is important to carry out plate control. For this purpose, it is necessary to accurately measure the camber shape generated in the hot rolled steel strip by rolling.

Therefore, in Japanese Patent Laid-Open No. 5-79832, at least three points are spaced apart in any running direction at the same time, and the measurements are repeated every time the steel strip runs a certain distance. An invention has been proposed in which the camber shape is obtained by calculating an approximate curve that maintains the relative positional relationship of the three points. According to the present invention, since the camber shape is based on the relative positional relationship between the three points, the camber shape can be measured if the simultaneity of the measured values at the three points is maintained.

Further, in Japanese Patent Laid-Open No. 58-68605, a camera provided at one point in the traveling direction of the steel strip is used to continuously capture images of the traveling steel strip at regular intervals. An invention has been proposed in which the camber shape of a steel strip is accurately calculated by comparing the images obtained in this manner.

Further, Japanese Patent Laid-Open No. 5-118840 proposes an invention in which an anamorphic lens mounted on a camera provided at one point in the traveling direction of a steel strip is used to simultaneously photograph the entire traveling steel sheet. ing. Usually, the steel strip is extremely long compared to the width, so if you try to fit the entire steel strip into the field of view using a normal imaging method, the lateral position resolution, which is important for measuring the camber shape, decreases. To do. Therefore, in the present invention, by using a special optical system (anamorphic lens) having different focal lengths in the width direction and the longitudinal direction of the steel strip, the width direction positional resolution of the steel strip is improved.

[0006]

However, in the invention proposed by Japanese Patent Laid-Open No. 5-79832, several meters are used.
It is necessary to install three or more board width gauges or board edge measuring machines at intervals. Therefore, there is a problem in securing the installation place of the measuring machine in the rolling line and the cost required for installing three measuring machines, and it is difficult to actually implement it.

Further, in the invention proposed in Japanese Patent Laid-Open No. 58-68605, since the correction is performed between the adjacent images, the error caused by this correction is integrated in the longitudinal direction of the steel strip, and the correction is accurate. It is not possible to find a perfect camber shape.

Further, the invention described in Japanese Patent Laid-Open No. 5-118840 requires a special optical system, which increases equipment costs. Also, although the number of measuring instruments installed can be covered by one, it is necessary to secure a sufficient field of view of the camera in order to shoot the entire steel plate. It is difficult to install.

As described above, according to the conventional technique, the camber shape generated when the hot rolled steel strip is manufactured by rolling cannot be accurately measured at low cost during rolling of the hot rolled steel strip. .

The present invention has been made in view of the above-mentioned problems of the prior art, and when a rolled metal strip such as a hot rolled steel strip is manufactured by rolling, a camber shape generated in the rolled metal strip is obtained. It is an object of the present invention to provide a method for measuring a camber shape of a rolled metal strip, a camber shape measurement device, and a rolling device that can be accurately and inexpensively measured during rolling of the rolled metal strip.

[0011]

[Means for Solving the Problems] As described above, when rolling is performed on the material for rolling the hot-rolled steel strip, a difference in elongation occurs at both ends in the width direction, and the hot-rolled steel strip that has passed through the rolling mill is subjected to this rolling. It bends in a generally arcuate shape in the horizontal plane with the machine as a fixed point. The present inventors have again fundamentally and in detail examined the occurrence state of this curved deformation. As a result, the present inventors have found that the curved deformation does not occur with a constant curvature in the longitudinal direction of the hot-rolled steel strip during rolling, but increases with the progress of rolling after the largest occurrence at the initial stage. It was found that the amount gradually decreased, and the increase amount of the curved deformation became zero after a certain timing.

That is, at the tip of the hot-rolled steel strip, a curved deformation occurs due to the difference in elongation on both widthwise ends. However, as the rolling progresses, the length and weight of the already-rolled portion, that is, the portion that has passed through the rolling mill increases, so the resistance to the hot-rolled steel strip bending in a substantially arc shape increases, and this increase in resistance As a result, the difference in elongation on both widthwise ends during subsequent rolling is reduced. For this reason, as the rolling progresses, the amount of increase in the curved deformation per unit time decreases, and at a certain point in time, the difference in elongation on both widthwise end sides becomes zero and the new curved deformation increases. The quantity becomes zero.

Therefore, as a result of further investigations by the present inventors on the basis of such a new knowledge regarding the occurrence of the curved deformation caused by rolling, the rolling progresses to a certain extent and the increased amount of the curved deformation occurs. After the point where the hot rolled steel strip becomes almost zero, the widthwise position of the end of the hot rolled steel strip is repeatedly detected in the longitudinal direction to obtain the widthwise end line or center line of the hot rolled steel strip. When measuring the shape of the strip, even if the measurement is performed with a measuring machine placed at one point in the running direction of the hot strip, the camber shape of the hot strip is accurately and accurately measured during rolling. Knowing that it can be measured at cost,
The present invention has been completed.

According to the present invention, when a metal strip is manufactured by rolling, the rear end portion of the metal strip is after or after the amount of increase in the curved deformation generated in the rolled metal strip becomes substantially zero or zero. Is a method for measuring the camber shape of a rolled metal strip, which comprises measuring the shape of the metal strip before leaving the rolling mill for rolling the metal strip.

In the method for measuring the camber shape of a rolled metal strip according to the present invention, it is exemplified that the shape of the metal strip is measured by using a measuring device arranged at one position in the traveling direction of the metal strip. It

From another point of view, the present invention is directed to the rear end of the metal strip after the amount of increase in the curved deformation generated in the metal strip produced by rolling is substantially zero or zero. Based on the output value of the width direction position measuring device, and the width direction position measuring device provided at a position corresponding to the existing position of the leading end of the metal band before the part exits the rolling mill for rolling the metal band. A camber shape measuring device for a rolled metal strip, comprising: a camber computing device for computing the shape of the metal strip.

In the camber shape measuring device for a rolled metal strip according to the present invention, it is exemplified that the width direction position measuring device is arranged at one position in the traveling direction of the metal strip. In these camber shape measuring devices for rolled metal strips according to the present invention, it is exemplified that the widthwise position measuring device measures one or both widthwise end positions of the metal strip.

From still another point of view, the present invention provides a rolling mill for rolling a metal strip, and an increase in the amount of curved deformation occurring in the metal strip manufactured by rolling is substantially zero or zero. After the time, the width direction position measuring device provided at the position where the rear end of the metal band corresponds to the existing position of the leading end part of the metal band before passing through the rolling mill, and the output value of this width direction position measuring device And a camber computing device for computing the shape of the metal strip based on the above.

In the rolling apparatus for rolled metal strips according to the present invention, it is illustrated that the width direction position measuring device is arranged at one position in the traveling direction of the metal strip. In these rolling devices for rolled metal strips according to the present invention, it is exemplified that the widthwise position measuring device detects one or both of the widthwise end positions of the metal strip.

In these rolling apparatus for rolled metal strips according to the present invention, the metal strip is a hot-rolled steel strip, the rolling mill is a rough rolling mill, and the width direction position measuring device is the rough rolling mill. Between the finishing rolling mill disposed downstream of this rough rolling mill, the maximum strip width of the hot-rolled steel strip to be produced is W (m
m), from the rough rolling mill, L ≧ {(5230W-
2687500) / (1.57 × 10 ⁻⁶ W)} ^1/2 , which are provided at positions separated by a distance L (mm) determined by.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for measuring a camber shape of a rolled metal strip, a camber shape measuring apparatus and a rolling apparatus for a rolled metal sheet according to the present invention will be described in detail below with reference to the accompanying drawings. In the following description, the case where the metal strip is a hot rolled steel strip and the width direction position detection device is provided between the rough rolling mill and the finishing rolling mill arranged downstream of the rough rolling mill is an example. Take

FIG. 1 is an explanatory view showing a rolling device 3 for a hot-rolled steel strip 2 incorporating a camber shape measuring device 1 of this embodiment. FIG. 1 (a) is a front view and FIG. b) is a plan view.

As shown in FIGS. 1 (a) and 1 (b), the rolling apparatus 3 of the present embodiment comprises a rough rolling machine 4, a width direction position measuring device 5 and a camber computing device 6. It has a camber shape measuring device 1 and a finish rolling mill 7. Hereinafter, these constituent elements of the rolling apparatus 3 will be sequentially described.

[Rough rolling mill 4] Rolling apparatus 3 of the present embodiment
Has a rough rolling mill 4. The rough rolling mill 4 is provided with a pair of small-diameter work roll pairs 4a and a pair of large-diameter backup roll pairs 4b, and rough-rolls a rolling material to produce the hot-rolled steel strip 2. In the present embodiment, this rough rolling mill 4 corresponds to the “rolling mill” in the present invention.

The rough rolling mill 4 may be of any known type, and is not limited to a specific type, so further description of the rough rolling mill 4 will be omitted. In the present embodiment, the rough rolling mill 4 is configured as described above.

[Camber Shape Measuring Apparatus 1] The rolling apparatus 3 of the present embodiment incorporates the camber shape measuring apparatus 1 as described above. The camber shape measuring apparatus 1 is a width direction position measuring apparatus. 5 and camber arithmetic unit 6
The width direction position measuring device 5 is arranged at a predetermined position between the rough rolling mill 4 and the finish rolling mill 7.
Therefore, these constituent elements of the camber shape measuring apparatus 1 will be described below.

(I) Width direction position measuring device 5 In this embodiment, as the width direction position measuring device 5, a strip width gauge 5 is installed between the rough rolling mill 4 described above and a finish rolling mill 7 described later. . Using this width direction position measuring device 5, the width direction end position of the hot rolled steel strip 2 is sequentially measured from the tip 2a of the hot rolled steel strip 2 in the longitudinal direction.

The widthwise position measuring device 5 in the present embodiment uses two cameras (or line sensors) 5a and 5b arranged above the hot rolled steel strip 2 to measure the widthwise end of the hot rolled steel strip 2. The position of the end portion in the width direction of the hot rolled steel strip 2 is calculated from the photographed image by signal processing, but the invention is not limited to such a measuring device 5, and the width of the hot rolled steel strip 2 is not limited to this. Any type can be used as long as it can measure the directional position.

That is, the width direction position measuring device 5 in the present embodiment can detect, for example, one or both of the width direction center position and the width direction end position of the hot-rolled steel strip 2, and the detected value The same applies to any device that can detect the widthwise position of the hot-rolled steel strip 2 based on the above.
For example, laser rangefinders are arranged on the left and right side surfaces of the hot-rolled steel strip 2, and the laser distance meter is used to measure the distance to the side surface of the hot-rolled steel strip 2. Scanning is performed above the hot-rolled steel strip 2. A light detecting section with a built-in vessel is provided and a light source that emits light upward is provided below, and the light detecting section is scanned in the width direction while hot rolling based on an image near the end of the hot rolled steel strip 2. A method of recognizing the ends of the steel strip 2 (for example, a photoelectric tube type that detects the positions of both ends by disposing a photodetector above both ends), and further a CCD image sensor above the hot-rolled steel strip 2. A method of recognizing both ends of the hot-rolled steel strip 2 by providing a camera with a built-in camera to photograph the widthwise end and image-processing the video signal (for example, two cameras are arranged above both ends. And various known end parts such as a CCD camera type capable of detecting both end parts) It is possible to use a detection means.

The widthwise position measuring device 5 detects the positions of both ends of the hot-rolled steel strip 2 by measuring the transport distance of the hot-rolled steel strip 2 using an appropriate means, for example, a pulse generator attached to a transport table. Then, each time the hot-rolled steel strip 2 advances by a constant interval, the positions of both ends of the hot-rolled steel strip 2 in the width direction are repeatedly detected in the longitudinal direction of the hot-rolled steel strip 2,
Done.

Further, the widthwise position measuring device 5 in this embodiment is the hot rolled steel strip 2 rolled by the rough rolling mill 4.
It is provided at a position that coincides with the existing position of the front end portion 2a of the hot-rolled steel strip 2 after the increase amount of the curved deformation that occurs in the above becomes substantially zero.

That is, in the present embodiment, at the "position corresponding to the existing position of the tip 2a of the hot-rolled steel strip 2", the increase amount of the curved deformation generated in the rolled hot-rolled steel strip 2 is substantially. It means zero or a position after the time when it becomes zero and before the rear end of the hot-rolled steel strip 2 passes through the rough rolling mill 4, and corresponds to the position where the front end 2a exists. When the maximum plate width of the hot-rolled steel strip 2 produced is W (mm),
Distance L (m from the rolling mill calculated by the following equation (1)
The positions are separated by m).

L ≧ {(5230W−2687500) / (1.57 × 10 ⁻⁶ W)} ^1/2 (1) Here, the distance L means in the present embodiment. It means the distance between the rough rolling mill 4 and the width direction position measuring device 5, and the center of the work roll 4 a of the rough rolling mill 4 and the end of the hot rolled steel strip 2 detected by the width direction position measuring device 5. It means the distance in the longitudinal direction between the parts.

Further, the width direction position measuring device 5 is provided at a position corresponding to the existing position of the tip portion 2a of the hot rolled steel strip 2 before passing through the rough rolling mill 4. That is, the width-direction position measuring device 5 measures the rough rolling of the hot-rolled steel strip 2 while the rough rolling device 4 is performing the rough rolling.
Are arranged apart from each other by a distance shorter than the maximum length of the hot-rolled steel strip 2.

The reason why the width direction position measuring device 5 is arranged at a distance L from the rough rolling mill 4 is as follows. The inventors of the present invention installed one end measuring instrument at a position where the influence of the camber shape generated in the hot-rolled steel strip 2 on the measurement result between the rough rolling mill 4 and the finish rolling mill 7 is minimal. It was thought that the camber shape could be measured accurately and easily by measuring the camber shape of the hot-rolled steel strip 2. Therefore, as a result of detailed investigation and consideration of the camber shape and the transport behavior of the hot-rolled steel strip 2 that are actually occurring, the present inventors have found the following matters (1) to (4).

(1) During rolling of the final stand of the rough rolling mill 4, the plate deviation is small at least immediately below the final stand, and the tip and tail ends of the hot-rolled steel strip 2 are slightly curved. This is because vertical mills (not shown in FIG. 1) for width reduction are juxtaposed immediately before the final stand, and the deviation of the hot-rolled steel strip 2 in the width direction is restricted. .

(2) When rolling in the rough rolling mill 4 in a left-right asymmetrical reduction state, a difference in elongation occurs between the left and right sides, so that the hot-rolled steel strip 2 on the outgoing side is curved in a substantially arc shape to form a camber. Exhibit a shape. If an accurate arc shape starting immediately below the rough rolling mill 4 grows along with rolling, the width deviation amount at the tip 2a of the hot-rolled steel strip 2 becomes a quadratic function as it goes away from the rough rolling mill 4. Will increase. From another point of view, in order to measure the shape of the hot rolled steel strip 2 only by the fixed point observation of the width deviation during conveyance, the length of the hot rolled steel strip 2 after rough rolling should be more than the length of the rough rolling mill 4. This means that the measuring machine must be placed at a distant position to perform the measurement. But in reality,
Due to the distance restriction between the rough rolling mill 4 and the finish rolling mill 7 and some existing equipment, it is often difficult to measure at a position sufficiently distant from the rough rolling mill 4.

(3) However, as a result of detailed investigation of the camber shape actually generated, the camber shape generated in the hot-rolled steel strip 2 is the strongest (small radius of curvature) near the tip 2a thereof, and is accompanied by rolling. There is a tendency for the distance to change gradually (larger radius of curvature), and moreover from the tip 2a to a number 1
It turned out that it hardly occurs at the portion 0 m away.

As a result of research on this cause, when the rolling length of the hot-rolled steel strip 2 becomes longer than a certain length, friction resistance between the hot-rolled steel strip 2 and the exit side table roller due to its own weight of the already-rolled portion causes a frictional resistance with the exit-side table roller. It was found that this is because it is difficult for the difference in elongation between the left and right to occur at the exit of the rolling deformation part. That is, as described above, as the arc shape grows due to the difference in left and right elongation, the velocity component in the strip width direction gradually increases near the tip 2a of the hot-rolled steel strip 2, and the hot-rolled steel strip 2 is conveyed. Sliding in the axial direction of the table roller. The frictional resistance acts on the rolling deformed portion as a bending moment, acts as a compressive force on the larger elongation and a tensile force on the smaller elongation, so that the difference in elongation gradually disappears. Since the effect of suppressing the difference in elongation increases as the rolling progresses, it immediately reaches a focused state, that is, a state where the difference in elongation is zero.

That is, the tip 2a of the hot-rolled steel strip 2 is rough-rolled, though it is somewhat changed depending on the plate thickness and width of the hot-rolled steel strip 2, and the strength of the left-right asymmetric rolling state that causes the camber shape. After the time when the hot-rolled steel strip 2 is away from the machine 4 by a predetermined distance or more, the curved deformation of the hot-rolled steel strip 2 does not newly occur, and the longitudinal movement amount and the width deviation amount of the hot-rolled steel strip 2 are measured at the fixed position. By doing so, the camber shape of the hot rolled steel strip 2 can be accurately measured.

(4) When measuring the shape of the tail end of the hot-rolled steel strip 2, since the hot-rolled steel strip 2 has passed through the final stand of the rough rolling mill 4, the entire width of the hot-rolled steel strip 2 is newly added. Since the directional velocity is not applied, the planar shape can be grasped with sufficient accuracy by the fixed point observation method.

Therefore, in the present embodiment, based on these new findings (1) to (4), the installation position of the width direction position measuring device 5 capable of accurately measuring the camber shape is set as follows. To determine.

As described above, the main cause of the camber shape occurring in the hot-rolled steel strip 2 passing through the final stand of the rough rolling mill 4 is, as described above, immediately below the final stand of the rough rolling mill 4. It is the difference in elongation between the left and right sides caused by the asymmetrical rolling condition such as the wedge of the hot rolled steel strip 2 and the temperature difference between the right and left sides.
In the present specification, the correction force necessary for suppressing the difference between the left and right elongations is referred to as a "camber correction required moment".

First, the inventors of the present invention have made extensive studies as to how much the maximum required camber correction moment generated by the above-mentioned left-right asymmetric condition in the final stand of the rough rolling mill 4 can be reached. As a result, it was found that the camber straightening required moment is mainly affected by the strip width of the rough rolling mill 4. Further, as the rolling progresses, the hot rolled steel strip 2
The rolling length at which the left-right elongation difference is zero is the camber correction required moment M1 which is the moment in the horizontal plane necessary for the left-right elongation difference to be zero, and the camber inhibition moment M2 which is the left-right elongation difference restraining moment. , That is, M1 ≦ M2.

Here, the camber correction required moment M1
Is a bending moment in the horizontal plane on the exit side of the rough rolling mill 4 to change the widthwise distribution of the longitudinal stress,
It can be obtained from a plastic stress analysis in which the difference between the left and right elongations caused by the asymmetric rolling is set to zero. Further, the camber suppression moment M2 is obtained by the frictional force acting between the hot-rolled steel strip 2 on the exit side of the rough rolling mill 4 and the conveying device.

FIG. 2 shows the relationship between the strip width of the hot-rolled steel strip to be rolled and the predicted value of the camber straightening required moment using the rolling conditions of the final stand of a general hot rolling rough rolling mill. 2 is a graph showing the results obtained by computer simulation. The graph of FIG. 2 shows that the final stand of the rough rolling mill has a reduction ratio of 25% or more, and the outgoing plate thickness of the rough rolling mill is 20%.
-50 mm, plate temperature: 900 [deg.] C. or higher is required under the most severe rolling conditions. Therefore, within the range of this rolling condition, the relationship of the equation (5) described later always holds.

As shown in the graph of FIG. 2, the relationship between the required camber correction moment M1 (N · m) and the plate width W (mm) is approximately approximated by a linear function, where t is the plate thickness (mm). I found that I can do it.

M1 = (25.6W-13169) t (2) On the other hand, as described above, when the rolling length of the hot-rolled steel strip 2 becomes longer than a certain amount, the weight of the already-rolled portion is increased by its own weight. Due to the frictional resistance with the side table roller, a difference in left and right elongation is unlikely to occur at the exit of the rolling deformation portion in the final stand of the rough rolling mill 4. This frictional resistance acts as a bending moment on the rolling deformation portion, and acts as a compressive force when the elongation is large and as a tensile force when the elongation is small. In the present specification, this force is referred to as "camber suppression moment".

The camber suppression moment M2 can be expressed by the following equation (3). M2 (N · m) = 9.8 × 10 -3 · μ · ρ · t · W · L 2/2 ····· (3) However, in (3), L is the roughing mill 4 The length (mm) of the hot-rolled steel strip 2 at the portion passing through the final stand is shown, ρ is the density (kg / mm ³ ) of the hot-rolled steel strip 2, and μ
Represents the coefficient of friction between the hot rolled steel strip 2 and the transport table,
W represents the width (mm) of the hot rolled steel strip 2, and t represents the thickness (mm) of the hot rolled steel strip 2.

The condition that the hot-rolled steel strip 2 after passing the final stand of the rough rolling mill 4 does not exhibit the camber shape is that the required moment for correcting the camber is equal to or less than the moment for suppressing the camber, that is, M1≤M2 is satisfied. is there. This condition is obtained by using the formula (2) and the formula (3).
When the length L of the hot-rolled steel strip 2 that has passed through the last stand is rewritten, it can be expressed by the following equation.

[0051]   L ≧ {(5230W-2687500) / (μ · ρ · W)}^1/2                                                       (4) The friction coefficient μ is about 0.2 in the case of a hot rolling mill.
It is estimated that there is. Further, the density ρ of the hot rolled steel strip 2 is
7.85 × 10 in case of general rolled material in rolling mill ^-6(Kg
/ Mm³). Therefore, equation (4) is transformed into equation (5).
Can be expressed as a function of the width of the hot-rolled steel strip 2.
It

L ≧ {(5230W−2687500) / (1.57 × 10 ⁻⁶ W)} ^1/2 (5) That is, at the position satisfying the expression (5), for camber measurement, If the width direction position measuring device 5 is installed and the hot rolled steel strip 2 running on the outlet side of the rough rolling mill 4 is measured, the camber shape of the hot rolled steel strip 2 can be accurately measured. .

(Ii) Camber Arithmetic Device 6 In the present embodiment, the camber measuring device 1 has a camber arithmetic device 6 in addition to the width direction position measuring device 5 described above. The camber calculation device 6 is provided in the width direction position detection device 5
This is a device for calculating the camber shape generated in the hot-rolled steel strip 2 based on the output value of.

More specifically, the camber computing device 6 uses information contained in the widthwise position of the hot-rolled steel strip 2 and information about the transport distance of the hot-rolled steel strip 2 which is repeatedly measured by a built-in program. Obtain one end line in the width direction of the hot rolled steel strip 2,
The camber shape of the hot rolled steel strip 2 is obtained from the obtained end line. However, the calculation method by the camber calculation device 6 is not limited to this form, and may be based on another method. For example, the width center line is obtained based on the information of both end positions in the width direction, the width center line is obtained from the information of the width center position and the transport distance of the hot rolled steel strip 2, and thereby the hot rolled steel strip is obtained. The camber shape of 2 may be obtained. According to this method, it is possible to eliminate the influence of the width variation in the longitudinal direction, and the camber shape of the hot-rolled steel strip 2 can be measured more accurately as compared with the method described above.

[Finishing Rolling Mill 7] The rolling mill 3 of this embodiment has a finishing rolling mill 7. The finish rolling mill 7 is disposed downstream from the rough rolling mill 4 by a predetermined distance, and includes a pair of small-diameter work rolls 7a and a pair of large-diameter backup rolls 7b. The finish rolling mill 7 finish-rolls the hot-rolled steel strip 2 that has been roughly rolled by the rough-rolling mill 4 to manufacture the hot-rolled steel strip 2 as a product.

The finish rolling mill 7 may be of any known type, and is not limited to a specific type, so further description of the finish rolling mill 7 will be omitted. In the present embodiment, the finish rolling mill 7 is configured as described above.

The rolling apparatus 3 for the hot-rolled steel strip 2 incorporating the camber measuring apparatus 1 of this embodiment is constructed as described above. Next, a situation in which the hot-rolled steel strip 2 is rolled by the rolling device 3 will be described.

When the final stand of the rough rolling mill 4 is rolled down, uneven elongation occurs on both widthwise ends of the hot-rolled steel strip 2, so that the hot-rolled steel strip 2 is deformed in a curved shape. . However, since the tip 2a side of the hot-rolled steel strip 2 that has undergone rough rolling gradually increases with the progress of rolling, the amount of curved deformation itself increases cumulatively as the rolling time increases. The increase amount of the curved deformation itself decreases with time as the rolling time increases.

When the tip 2a of the hot-rolled steel strip 2 reaches the position separated from the rough rolling mill 4 by the distance L, that is, the position A, the increase amount of the curved deformation becomes zero. Further, at the position A, as described above, the width direction position measuring device 5 is installed.

For this reason, the shape of the hot-rolled steel strip 2 can be measured by using the width-direction position measuring device 5 to sequentially obtain the widthwise end line or center line of the hot-rolled steel strip 2 in the longitudinal direction. Then, even if the measurement is performed with a measuring machine arranged at one point in the traveling direction of the hot-rolled steel strip 2, the camber shape generated in the hot-rolled steel strip 2 can be accurately and inexpensively produced during rolling. Can be measured.

[0061]

EXAMPLES The present invention will be described in detail with reference to examples. FIG. 3 is a side view showing the configuration of the rolling apparatus 3 of FIG. 1 described above. In FIG. 3, 8 indicates a table roller and 9 indicates a pulse generator.

In this embodiment, as shown in FIGS. 1 and 3, in a rolling apparatus 3 for a hot-rolled steel strip 2 provided with a rough rolling mill 4 and a finish rolling mill 7 (neither shown), a rough rolling mill 4 and The width direction position measuring device 5 (two cameras 5a, 5b for photographing both ends of the hot rolled steel strip 2) is provided at a plurality of positions different in distance from the rough rolling mill 4 with the finish rolling mill 7. )
Was installed.

Both ends of the hot-rolled steel strip 2 are photographed by using the two cameras 5a and 5b, the photographed video signals are subjected to image processing to obtain the widthwise positions of the both ends, and the widthwise positions of the both ends. The width center position was obtained from the above, and the longitudinal distribution of the width center position of the hot rolled steel strip 2, that is, the width center line was obtained from this width center position and the information on the transport distance of the hot rolled steel strip 2. The transport distance of the hot rolled steel strip 2 was measured using a pulse generator provided on the transport roller of the hot rolled steel strip 2.

FIG. 4 is a graph showing the relationship between the minimum value of L satisfying the expression (5) and the strip width of the hot-rolled steel strip 4. The coefficient of friction between the hot-rolled steel strip 4 and the table roller 8 is μ = 0.
2, and the density of the hot-rolled steel strip 4 is ρ = 7.85 × 10 ^-6 kg
/ Mm ^3, and the width of the rough bar is 700 mm minimum and 1 maximum.
It was 670 mm.

As shown in the graph of FIG. 4, the distance L increases as the plate width W of the hot-rolled steel strip 2 increases. Therefore,
The case of the maximum strip width of the hot-rolled steel strip 2 manufactured by the target rolling facility may be set as the maximum value of the distance L. Figure 4
In the case of the graph, if W: 1670 mm or less, L: 48.8 m or more.

That is, at a position away from the final stand of the rough rolling mill 4 toward the finish rolling mill 7 by about 49 m or more,
If the widthwise end positions (one or both end positions) of the hot-rolled steel strip 2 are measured, the camber shape of the hot-rolled steel strip 2 can be accurately measured even if one widthwise position measuring device 5 is used. It becomes possible to measure. Therefore, the verification was performed in an actual hot rolling line as follows.

That is, behind the rough rolling mill 4, a widthwise position measuring device 5 for a plurality of hot-rolled steel strips 2 was provided at a plurality of positions at different distances from the final stand. Specifically, it was set at a distance of 45 m, 55 m, and 65 m from the final stand of the rough mill. This device synchronizes the width center position from the tip to the tail of the hot-rolled steel strip 2 with the coarse bar conveying distance measuring device by the pulse generator attached to the table roller, and every time the coarse bar travels a fixed distance. The measurement was performed. An example of the measurement results is shown in graphs in FIGS. 5 (1) to 5 (3).

As a result, the width is 1670 mm and the thickness is 31 mm.
For the hot-rolled steel sheet 2 of No. 2, changes in the width center position obtained at the positions of 55 m and 65 m (Fig. 5 (2),
(3)) has almost the same shape, and it can be seen that the camber shape of the hot-rolled steel strip 2 can be measured almost accurately.

On the other hand, in the result obtained at the position of 45 m (FIG. 5 (1), the shape of the tip is different from the other two data, and the width direction position measuring device 5 is located at the position 55 m or more apart. It is understood that the camber shape of the hot rolled steel strip 2 cannot be accurately measured unless the hot rolled steel strip 2 is installed to measure the shape of the hot rolled steel strip 2.

Further, if the installation position of the width direction position measuring device 5 is too far from the rough rolling mill 4, the width direction position measuring device 5 approaches the first stand of the finish rolling mill 7, and a long heat In the case of the rolled steel strip 2, the measurement is carried out in a state of being caught in the finish rolling mill 7. Therefore, there is a possibility of being affected by the left-right asymmetric rolling conditions in the first stand of the finish rolling mill 7, and a measuring device should be provided at a position as close as possible to the rough rolling mill 4 within a range satisfying the above formula (4). Is desirable.

In the application where the measurement result of the camber shape in this embodiment is utilized for setting the rolling condition of the finish rolling mill 7, the width direction position measuring device 5 is located at a position suitable for the setup of the finish rolling mill 7. Is desirable.

[0072]

As described in detail above, according to the present invention, when a rolled metal strip such as a hot-rolled steel strip is manufactured by rolling, the camber shape generated in the rolled metal strip is determined by rolling the rolled metal strip. It was possible to provide a method for measuring the camber shape of a rolled metal strip, a camber shape measuring apparatus, and a rolling apparatus that can be accurately measured at low cost.

Specifically, according to the present invention, the camber shape can be accurately measured with only one width direction position measuring device. Further, it is not necessary to use a special optical system for the width center position measuring device as in the conventional technique. Therefore, according to the present invention, it is possible to reduce the introduction cost of the device.

The significance of the present invention having such effects is extremely significant.

[Brief description of drawings]

1 is an explanatory view showing a rolling apparatus for hot-rolled steel strips in which a camber shape measuring apparatus of an embodiment is incorporated, and FIG.
1A is a front view, and FIG. 1B is a plan view.

FIG. 2 is a computer simulation showing the relationship between the strip width of the hot-rolled steel strip to be rolled and the predicted value of the required camber straightening moment, using the rolling conditions of the final stand of a general hot rolling rough rolling mill. It is a graph which shows the result obtained by.

FIG. 3 is an explanatory diagram showing a configuration of a rolling device used in an example.

FIG. 4 is a graph showing the relationship between the minimum value of L that satisfies expression (5) and the strip width of the hot-rolled steel strip.

FIG. 5 is a graph showing the results of Examples.

[Explanation of symbols]

1 Camber shape measuring device 2 Hot rolled steel strip 3 Rolling equipment 4 rough rolling mill 5 Width direction position measuring device 6 Camber computing device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manabu Eto             4-53 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture             Sumitomo Metal Industries, Ltd. F term (reference) 2F069 AA02 AA06 AA15 AA52 BB19                       BB34 CC06 GG04 GG07 GG58                       GG62 HH09 HH13 HH30 JJ12                       JJ23 KK08 NN00 PP07                 4E024 AA06 AA08

Claims (9)

[Claims] 1. When a metal strip is manufactured by rolling, the rear end portion of the metal strip is the metal strip after the amount of increase in the curved deformation generated in the rolled metal strip becomes substantially zero. A method for measuring a camber shape of a rolled metal strip, comprising measuring the shape of the metal strip before leaving the rolling mill for rolling the strip. 2. The method for measuring the camber shape of a rolled metal strip according to claim 1, wherein the measurement of the shape is performed by using a measuring device arranged at one position in the traveling direction of the metal strip. 3. The rolling of the metal strip produced by rolling the metal strip after the increase in the amount of curved deformation occurring in the metal strip becomes substantially zero and the rear end of the metal strip is rolled to the metal strip. The width direction position measuring device provided at a position corresponding to the existing position of the tip of the metal band before leaving the rolling mill, and the shape of the metal band is calculated based on the output value of the width direction position measuring device. A camber shape measuring device for a rolled metal strip, comprising: 4. The camber shape measuring device for a rolled metal strip according to claim 3, wherein the width direction position measuring device is arranged at one position in a traveling direction of the metal strip. 5. The camber shape measuring device for a rolled metal strip according to claim 3, wherein the widthwise position measuring device measures one or both widthwise end positions of the metal strip. 6. A rolling mill for rolling a metal strip, and a rear end of the metal strip after and after an increase in the amount of curved deformation of the metal strip produced by rolling is substantially zero. The width direction position measuring device provided at a position corresponding to the existing position of the leading end of the metal band before the section exits the rolling mill, and the shape of the metal band based on the output value of the width direction position measuring device. A rolling device for rolled metal strips, comprising: a camber computing device for computing. 7. The rolling device for rolled metal strips according to claim 6, wherein the width direction position measuring device is arranged at one position in the traveling direction of the metal strip. 8. The rolling metal strip rolling apparatus according to claim 6, wherein the widthwise position measuring device detects one or both of the widthwise end positions of the metal strip. 9. The metal strip is a hot-rolled steel strip, the rolling mill is a rough rolling mill, and the width direction position measuring device is disposed on the rough rolling mill and downstream of the rough rolling mill. Between the finishing rolling mills and the maximum strip width of the hot-rolled steel strip to be manufactured is W (mm), the distance L ( mm), the rolling device for rolling metal strips according to any one of claims 6 to 8, which is provided at positions separated from each other. L ≧ {(5230W-2687500) / (1.57 × 10 ⁻⁶ W)} ^1/2 ... (1)