JP3325496B2 - Steel strip winding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for winding a steel strip in a hot rolling facility for a steel strip.

[0002]

2. Description of the Related Art A winding device generally called a coiler is installed downstream of a continuous hot rolling mill for steel strip (also called a hot strip mill). FIG. 6 shows an example of the structure of the coiler. 1 (1a, 1b) is a pinch roll, 2 is a throat guide, 3 (3a, 3b, 3c, 3d) is, for example, four wrapper rolls, 4 (4a, 4b, 4c, 4d) is an apron between wrapper rolls, 5 is a mandrel.

A steel strip S which has traveled horizontally through a hot run table (not shown) is installed obliquely, bent downward by pinch rolls 1a and 1b having different diameters at the top and bottom, guided by a throat guide 2, and guided by a mandrel. Of the four wrapper rolls 3 arranged around the first wrapper roll 3 reach the gap between the first wrapper roll 3a and the mandrel 5 which come into contact first, and the mandrel 5 and the four wrapper rolls arranged around the mandrel 5 3 (3a to 3d) and an apron 4 (4a to 4d) provided therebetween surrounds the mandrel 5, and is wound around a coil.

[0004] Here, the most problematic point in winding is that when the leading end of the entering steel strip S has a slightly upward curving tendency, it comes into contact with the first wrapper roll 3a and then moves to the exit side. The first apron 4a provided collides with and slams the first apron 4a, and the apron 4a is damaged, or the tip of the steel strip S is bent and overlapped here, so that it cannot be wound around the mandrel 5 and cannot be wound. is there.

FIG. 7 schematically shows the behavior of the leading end of the steel strip S during winding in a time series.
At the time point (a), the steel strip S advances in the throat guide 2, and the tip thereof contacts the mandrel 5 and is carried by the mandrel 5 to the left in the drawing. At the time point (b), since the throat guide 2 is above the tangent line of the mandrel 5 at the contact position between the first wrapper roll 3a and the mandrel 5, the tip of the steel strip S has a certain incident angle θ and the wrapper roll 3a. Is bitten. As a result, the steel strip S is warped on the outlet side of the wrapper roll 3a, as shown in part A of FIG. It is sufficient to proceed along the inner surface of the apron 4a as shown in (d), but if the warpage is severe,
The leading end strikes the gap g between the wrapper roll 3a and the apron 4a, causing an accident.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve this problem, to determine the setting conditions of a throat guide and a wrapper roll, and to eliminate a roll-up accident such as slashing regardless of the sheet thickness. And

[0007]

As a result of repeating observation and analysis of the behavior of the tip of the steel strip S, the present inventors found that the relationship between the incident angle θ and the amount of warpage H was correlated, The quantity H is
Since it was found that there was a correlation with the gap (δ) between the first wrapper roll and the mandrel and the difference (δ−t) between the thickness t of the steel strip to be wound (hereinafter referred to as the clearance), Based on the knowledge, the setting conditions of the wrapper roll were reviewed, and the problem was solved.

That is, the method for winding a steel strip according to the present invention comprises:
In a winding method of a steel strip using a winding device in which a plurality of wrapper rolls are arranged around a mandrel, when a leading end of the steel strip to be wound passes through a gap between the mandrel and the first wrapper roll, a first winding is performed. The angle between the tangent of the mandrel at the point of contact between the wrapper roll and the mandrel and the steel strip to be wound is in the range of -10 degrees to +15 degrees, the gap δ between the first wrapper roll and the mandrel, The difference (δ-t) from the thickness t of the steel strip to be taken is 2 mm to 5 mm
Is maintained in the range of

Further, the steel strip winding device of the present invention is a steel strip winding device comprising a plurality of wrapper rolls arranged around a mandrel. A throat guide installed at an angle of 0 ° to + 15 ° with respect to a tangent line of the mandrel at the contact point toward the contact point between the wrapper roll and the mandrel; A wrapper roll opening changing means for changing the gap δ, and a difference (δ-t) between the gap δ and the thickness t of the steel strip when the leading end of the steel strip to be wound passes through the first wrapper roll. And control means for operating the wrapper roll opening degree changing means so that the angle is within a range of 2 mm to 5 mm .

[0010]

FIG. 2 is a graph obtained by plotting the behavior of the tip of a steel strip S by high-speed video analysis on a curve for which the amount of warpage is obtained by calculation. Corners, first wrapper roll 3a and mandrel 5
Between the tangent L of the mandrel 5 and the point of contact with the mandrel 5
And the amount of warpage H is plotted on the vertical axis. FIGS. 3A and 3B show the incident angle θ, the distance δ between the first wrapper roll 3a and the mandrel 5, and the amount of warpage H at this time. The case where the incident angle θ shown in FIG. 3A is close to 0 is referred to as pattern 1, and the case where the incident angle θ is large in both the plus and minus directions shown in FIG. 3B is referred to as pattern 2. As shown in FIG. 3 (a), in pattern 1, the steel strip S can pass through the gap between the wrapper roll 3a and the mandrel 5 almost linearly, so that no large warpage occurs. As shown in FIG. 2, in this range, there is a negative correlation between the incident angle θ and the amount of upward warpage H, and the amount of upward warpage H decreases as the incident angle θ increases from the negative side to the positive side. On the other hand, in the case of the pattern 2, the absolute value of the incident angle θ is large, and the steel strip S is deformed into an arc shape in contact with the wrapper roll 3a or the mandrel 5. The larger the angle of incidence θ, the greater the amount of warpage H.

When the amount of upward warpage H reaches a height G from the tangent line L to the tip of the apron 4, for example, 25 mm, a collision occurs. Incidentally, the relationship between the incident angle θ and the amount of warpage H shown in FIG. 2 originally assumes that no warpage occurs before the steel strip S reaches the coiler, but in actual operation, the steel strip S Before reaching the coiler, there is already an amount of warpage of about 10 mm (otherwise, a hit accident at the hot run table will occur), so the allowable value of the amount of warpage H in the wrapper roll is 25 minus 10 At 15mm
It is about. According to FIG. 2, if the incident angle θ is set in the range of −10 degrees to +15 degrees, the clearance (δ−t) becomes 1.3 to
It can be seen that the amount of warpage H can be suppressed within 15 mm within the range of 10 mm.

As shown in FIGS. 6 and 7, a throat guide 2 for guiding the steel strip S to an intermediate position between the first wrapper roll 3a and the mandrel 5 is provided on the entry side of the first wrapper roll 3a.
Is provided. First wrapper roll at the end of steel strip S
The incident angle θ to 3a changes depending on the setting conditions of the throat guide 2. FIG. 4 is an explanatory diagram showing the relationship between the first wrapper roll 3a, the mandrel 5, and the throat guide 2. The present inventors pointed the throat guide 2a to the contact point between the first wrapper roll 3a and the mandrel 5, as shown by the solid line,
Angle α between the tangent line L of the mandrel 5 passing through the contact point and the throat guide 2a (hereinafter referred to as the throat guide angle)
And the direction of the throat guide 2b is shifted by 50 mm from the contact point between the first wrapper roll 3a and the mandrel 5 toward the first wrapper roll 3a as shown by a broken line, When the throat guide angle α was changed, the change in the incident angle θ at the tip of the steel strip S was investigated by high-speed video analysis. The result is shown in FIG. When the throat guide 2 is directed toward the contact point between the first wrapper roll 3a and the mandrel 5, the incident angle θ can be made smaller, and further, the throat guide 2 is connected to the first wrapper roll 3a.
The angle of incidence can be suppressed to 15 degrees or less by directing the contact point between the mandrel 5 and the mandrel 5 and setting the throat guide angle α to 15 degrees or less.

FIG. 2 plots the calculation results of the amount of warpage when the clearance of the steel strip passing through the first wrapper roll is 1.3 to 10 mm. From this figure, if the incident angle θ is set within the range of -10 degrees to +15 degrees, the amount of warpage H is set within the range of 1.3 to 10 mm.
Can be reduced to 15mm or less, but the clearance
If it is in the range of about 5 mm, the amount of warpage H can be made 13 mm or less. Therefore, in consideration of safety, the clearance is preferably in the range of 2 to 5 mm.

Conventionally, the standby gap δ of the wrapper roll has been set to a fixed value such as k times (k: constant) the thickness t of the steel strip S. For example, if k = 1.5, the clearance (δ-t) is 0.5 t, which varies depending on the thickness t of the steel strip to be wound. When the thickness t is less than 4 mm, the clearance is 2 t.
As a result, even if the incident angle θ was about 15 degrees, as shown in FIG. 2, the amount of warpage was larger than 13 mm, so that a collision accident was likely to occur.

[0015]

FIG. 1 shows an embodiment of the present invention. This is a partial cross-sectional view showing the vicinity of the first wrapper roll of the coiler, and the same reference numerals are used for those common to the respective drawings. Reference numerals 10 and 11 denote wrapper roll opening change means, 10 is a hydraulic cylinder, 11 is a servo valve for operating the hydraulic cylinder 10, and 12 is a wrapper roll opening control device for controlling the servo valve 11.

That is, for the throat guide 2 on the entry side of the first wrapper roll 3a: 1) The direction of the throat guide is directed to the contact point (kiss touch point) between the wrapper roll and the mandrel. 2) Set the angle α of the throat guide at 0 ° to +15 with respect to the tangent line of the mandrel passing through the contact point between the wrapper roll and the mandrel.
Within the range of degrees. 3) The position of the tip of the throat guide is within 250 mm from the point of contact between the wrapper roll and the mandrel. Was set as the setting condition.

In the conventional throat guide shown by imaginary lines in FIG. 1, an accident often occurred because the angle of incidence of the steel strip S was about 30 degrees and the direction of the throat guide was above the kiss touch point. According to the present invention, the throat guide angle is set to, for example, 12 degrees according to the above-described procedure, and the direction is directed to the kiss touch point. The gap δ between the first wrapper roll 3a and the mandrel 5 can be arbitrarily changed by the hydraulic cylinder 10. The hydraulic cylinder 10 operates by transmitting a control signal from the wrapper roll opening control device 12 to the servo valve 11. The wrapper roll opening controller 12 determines the gap δ based on the steel strip thickness information sent from a higher-level computer (not shown), and operates the hydraulic cylinder 10.

The steel strip S was wound by using the above apparatus. The standby gap of the first wrapper roll 3a, that is, the gap δ between the first wrapper roll 3a and the mandrel 5 is set to (t +
3) mm, that is, the clearance (δ-t) was kept constant at 3 mm. As a result, even in the case of a sheet thickness of 3 mm or less, which was liable to cause a smashing accident, a steel strip was formed on the exit side of the first wrapper roll 3a. The tip of S did not warp, preventing the occurrence of a smashing accident.

Although the servo valve and the hydraulic cylinder have been described as examples of the wrapper roll opening changing means, the present invention is not limited to this, and an electric motor or the like may be used.

[0020]

According to the present invention, the collision of the tip of the steel strip with the apron is reduced, and the angle of contact with the apron is reduced, so that the loop amount in the apron is also reduced and the winding inside the coil is reduced. There is an excellent effect that productivity and quality are improved, for example, slackness is eliminated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a structure around a coiler according to the present invention.

FIG. 2 is a graph showing the relationship between the angle of incidence of a steel strip tip on a first wrapper roll and the amount of warpage in a coiler.

FIG. 3 is a schematic view showing the behavior of a steel strip tip corresponding to the pattern of FIG. 2;

FIG. 4 is a schematic view of a main part of the coiler showing a throat guide angle.

FIG. 5 is a graph showing a relationship between a throat guide angle and an incident angle of a steel strip tip.

FIG. 6 is a configuration diagram showing a structure around a conventional general coiler.

FIG. 7 is a schematic view showing the behavior of the tip of a steel strip in a conventional general coiler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pinch roll 2 Throat guide 3 Wrap roll 4 Apron 5 Mandrel 10 Hydraulic cylinder 11 Servo valve 12 Wrap roll opening control device L Mandrel tangential line S Steel strip g Gap (between wrap roll and apron) t Plate thickness α Throat guide angle δ Gap between wrapper roll and mandrel θ Incident angle H Warpage

Continuing from the front page (72) Inventor Masashi Shimizu 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Inside the Chiba Works (72) Inventor Taichi Kukizaki 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Inside the Chiba Works (72) Inventor Hiroshi Takayo 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Ishikawajima-Harima Heavy Industries, Ltd.Yokohama Engineering Center (72) Inventor Hisashi Sato 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Address Ishikawajima-Harima Heavy Industries, Ltd., Yokohama Engineering Center (72) Inventor Hiroaki Kuwano 1, Shinnakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture, Ishikawajima-Harima Heavy Industries, Ltd. Yokohama Engineering Center (56) References JP-A-61-147922 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21C 47/06

Claims (2)

(57) [Claims] In a method for winding a steel strip using a winding device in which a plurality of wrapper rolls are arranged around a mandrel, a tip of the steel strip to be wound passes through a gap between the mandrel and the first wrapper roll. At this time, the angle between the tangent of the mandrel at the contact point between the first wrapper roll and the mandrel and the steel strip to be wound is in the range of -10 degrees to +15 degrees, and the angle between the first wrapper roll and the mandrel is Difference (δ-t) between gap δ and thickness t of steel strip to be wound
Is maintained in the range of 2 mm to 5 mm. Wherein the periphery of the mandrel Le a plurality of Rapparo
In the winding apparatus of the strip formed by arranging the Le, the first Rapparo Le entry side, a first Rapparo Le and mandrel
Towards the point of contact with Le, and Surotogai de disposed in at an angle of +15 degrees to 0 degrees to for the <br/> tangent line of the mandrel Le at the contact point, the first Rapparo Le and mandrel
Wrapper roll opening change hands for changing the gap δ between the Le
And stage, the difference between the gap [delta] and the steel strip plate thickness t when the leading end of the steel strip for winding passes through the first Rapparo Le ([delta]-t) is
2mm to take-up of the steel strip, characterized in that a control hand stage for operating the wrapper roll opening changing means to be in the range of 5 mm.