JPH0985324A - Strip meandering prevention control method - Google Patents

Abstract

(57) An object of the present invention is to provide a meandering prevention control method when a strip is threaded through a threading roll having a crown in a steel manufacturing process line. SOLUTION: A strip displacement amount sensor 5 for measuring a distance to a surface of a strip 1 is attached in the vicinity of an auxiliary roll 3 to measure a distance between a sheet passing roll 2 and a strip 1 at the time of passing a sheet and measure the distance. The pressing mechanism 4 is operated according to the value of the distance, and the auxiliary roll 3 is pressed against the surface of the strip 1 from the direction perpendicular to the surface to control the auxiliary roll 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a meandering prevention control method for passing a strip through a sheet passing roll having a crown in a process line.

[0002]

2. Description of the Related Art In a steel manufacturing process line, strips are usually threaded through threading rolls. But,
Since the strip often causes meandering and makes the threading unstable, a threading roll having a crown for the self-correcting effect of the roll is generally used.

The effect of the threading roll having a crown depends on the size of the crown, but there is a limit to the enlargement of the crown due to restrictions such as generation of heat buckles. In addition, when the strip is stretched to one side or the like, proper meandering correction cannot be performed. As an example of such measures, Japanese Patent Laid-Open No. 5-27
Japanese Patent No. 7536 discloses that when a strip (herein referred to as a steel plate) is threaded through a threading roll having a crown, an auxiliary roll having a pressing mechanism is provided on the strip entrance side of the threading roll, and A method has been proposed in which the amount of meandering in the width direction of the strip is detected in front of the auxiliary roll at the time of boarding, and the pressing mechanism is operated according to the amount of meandering to press the auxiliary roll against the surface of the strip for control. .

[0004]

However, the meandering preventing method as disclosed in Japanese Patent Laid-Open No. 5-277536 has the following problems. Since there is a certain distance between the meandering amount detection sensor and the sheet passing roll, the meandering correction cannot be performed at the instant when the meandering occurs. Further, since the meandering amount sensor detects the meandering only after the meandering, the meandering cannot be prevented in advance. Further, the method of pressing the auxiliary rolls at all times is not a good idea from the viewpoint of increasing maintenance costs due to roll wear.

The present invention has been made to solve the problems of the prior art as described above, and it is possible to sufficiently correct the meandering by a generally used sheet passing roll having a crown. It is an object of the present invention to provide a strip meandering prevention control method.

[0006]

In order to achieve the above object, the present invention provides an auxiliary having a plate passing roll having a crown and a pressing mechanism provided on the strip entrance side of the plate passing roll in a steel manufacturing process line. In passing the strip through the roll, measuring the distance between the strip and the strip in the vicinity of the auxiliary roll at the time of passing,
A strip meandering prevention control method is characterized in that the pressing mechanism is operated according to the value of the measured distance to control the auxiliary roll by pressing it against the surface of the strip.

[0007]

First, the principle of the present invention will be described below. The reason why the strip, which has been threading stably until then, suddenly meanders is nothing but the reduction of the frictional force between the threading roll and the strip, except for the defective shape of the strip. Therefore, due to the reduction of the frictional force, the centering force of the strip due to the crown of the threading roll is reduced and the strip meanders.

Then, in order to clarify why the frictional force is reduced, the inventors of the present invention have conducted extensive research on the behavior of the strip for many years, and found that the distance between the threading roll and the strip was It turns out that there is a significant relationship to size. That is, when the distance between the threading roll and the strip increases, the contact point between the threading roll and the strip decreases microscopically, and apparently,
The coefficient of friction between the threading roll and the strip is reduced, and the frictional force is reduced. Reasons for increasing the distance include a decrease in strip tension and the entrainment of air and liquid between the threading roll and the strip. The distance at which the meandering starts is different depending on the surface patterns of the sheet passing roll and the strip, so it is necessary to experimentally determine the average surface roughness of the sheet passing roll R _a1 and the average surface roughness of the strip R _a2. In many cases, it is about R _a1 + R _a2 .

Therefore, in the present invention, as described above,
Since the distance between the strip running roll having a crown and the strip is measured and used as the material for determining the occurrence of meandering, it is possible to prevent the meandering by pressing the auxiliary roll very quickly when the meandering occurs. By managing the tendency of the distance, advance prediction and prevention of meandering can be realized.

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention. In this figure, 1 is a strip, 2 is a sheet passing roll having a crown, 3 is an auxiliary roll provided on the strip entrance side of the sheet passing roll 2, 4 is a pressing mechanism such as a fluid cylinder, and 5 is a substantially central position of the strip 1. A strip displacement sensor, such as an eddy current displacement gauge, attached to the sensor 6, is a controller. This control device 6
Is composed of an interface 7, an arithmetic unit 8, a command unit 9, a display unit 10, and a storage unit 11.

With this structure, when the strip 1 is passed through the strip passing roll 2, the distance signal detected by the strip displacement sensor 5 is input to the arithmetic unit 8 through the interface 7. Is calculated.
Therefore, the command device 9 outputs a control command to the pressing mechanism 4 according to the change in the distance to operate, and controls the auxiliary roll 5 to press it from the direction perpendicular to the strip 1. The calculation result and the content of the control command are displayed on the display device 10 and stored in the storage device 11.

The method of measuring the distance between the strip 1 and the sheet passing roll 2 by the strip displacement amount sensor 5 will be described below. Now, it is assumed that the auxiliary roll 3 and the strip displacement amount sensor 5 with respect to the sheet passing roll 2 have a positional relationship as shown in FIG. That is, the auxiliary roll 3 has a distance H below the axis 2a of the plate roll 2.
_It is assumed that the strip displacement amount sensor 5 is attached at the position _R , and the strip displacement sensor 5 is attached at an angle θ with respect to the shaft core 2a of the plate roll 2 and at a position at a distance L _S laterally.

Therefore, if the position of the surface of the strip 1 threaded by the strip displacement amount sensor 5 is measured and the distance is L _M , the distance L _X between the strip 1 and the threading roll 2 is , Is calculated by the following formula. L _X = (L _S −r) −L _M Here, r is the radius of the sheet passing roll 2.

The values of the above distances H _R , H _S , and L _S are usually 6 with respect to the radius r of the sheet passing roll 2.
r, 0 to 60 ° C., r + 10 mm is suitable. Further, in the above configuration, one strip displacement amount sensor 5 has been described as being attached at substantially the center position of the strip 1, but if it is provided on both sides, the accuracy of measurement can be further improved.

[0015]

EXAMPLES Specific application examples of the method of the present invention will be described below. 350mmφ × 1400mmL (crown on one side 400mm
L) and the auxiliary roll 3 of 80 mmφ × 1400 mmL was provided at a position about 1000 mm downward from the position of the axis of the plate passing roll 2. On both ends of this auxiliary roll 3,
A pressing mechanism 4 using a cylinder is attached so that the auxiliary roll 3 can be pressed against the strip 1. Also,
The strip displacement sensor 5 is located above the auxiliary roll 3.
It was attached at a position of 10 mm and a position of 80 mm laterally from the axis of the threading roll 2.

Then, a thin steel plate having a thickness of 0.2 mm and a width of 1000 mm was passed through the sheet passing roll 2. As the line speed increases, the displacement of strip 1 increases and the line speed becomes 8
Displacement in 00mpm is 16 [mu] m (= average surface roughness Ra ₂ of the strip 1; mean of 10 [mu] m + passing plate roll 2 surface roughness Ra _1; 6
μm) has been reached. At this time, the control device 6 was turned off. The line speed was further increased to 900 mpm, and meandering occurred when the displacement amount reached 18 μm, so the control device 6 was turned on and the pressing mechanism 4 of the auxiliary roll 3 was operated to press the auxiliary roll 3 against the strip 1. It was As a result, the winding of the strip 1 of the sheet passing roll 2 corrected the meandering and became a normal state.

Based on the above results, the control device 6 is set so that the pressing mechanism 4 operates at the displacement amount of 15 μm, and the line speed is increased from 0 mpm to 1000 mpm. Line speed = 900mpm
The pressing mechanism 4 was activated before and after, and the line speed could be increased to 1000 mpm without meandering. In the present invention, as described above, the amount of displacement of the strip is detected by the strip passing amount sensor and the strip displacement amount sensor in the vicinity of the strip, and accordingly, the pressing to the strip is immediately performed by the auxiliary roll. The strip is always wound well. As a result, the strip passing roll-
Since the friction between the strips can always secure a certain value or more, a sufficiently normal state can be maintained by self-correction.

[0018]

As described above, according to the present invention,
In passing a strip through a sheet passing roll having a crown in a steel manufacturing process line and an auxiliary roll having a pressing mechanism provided on the strip entrance side of the sheet passing roll, in the vicinity of the auxiliary roll at the time of sheet passing. The distance between the threading roll and the strip is measured, and the pressing mechanism is operated according to the value of the measured distance to press and control the auxiliary roll against the surface of the strip. It is possible to sufficiently wind the strip around the sheet passing roll, and thereby, the strip can be passed stably without always meandering.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a positional relationship of each constituent member used in the present invention.

[Explanation of symbols]

 1 Strip 2 Rolling Roll 3 Auxiliary Roll 4 Pressing Mechanism 5 Strip Displacement Sensor 6 Controller 7 Interface 8 Computing Device 9 Command Device 10 Display Device 11 Storage Device

Claims (1)

[Claims] 1. When passing a strip through a sheet passing roll having a crown and an auxiliary roll having a pressing mechanism provided on the strip entrance side of the sheet passing roll in a steel manufacturing process line, the above-mentioned method is used when the strip is passed. Measuring the distance between the strip passing roll and the strip in the vicinity of the auxiliary roll and operating the pressing mechanism according to the value of the measured distance to control the auxiliary roll by pressing it against the surface of the strip. A strip meandering prevention control method characterized by the above.