JPH11226621A - Method for suppressing upward camber of hot rolling material and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the upward camber of a rolling material without using an expensive measuring device such as a thermometer. SOLUTION: This device is provided with upper and lower rolls 2, 4 which are driven with driving units 3, 5, a sensor 6 for detecting the upward camber of the rolling material 1 which is rolled with these upper and lower rolls 2, 4 and, when the output of this sensor is received, an upper/lower roll velocity ratio table from which the upper/lower roll velocity ratio so as to suppress the upward camber of the rolling material 1 is outputted corresponding to the thickness of the rolling material 11. In such a case, the driving units 3, 5 are controlled so that the upper and lower rolls 2, 4 are driven along the upper/lower roll velocity ratio with a controller 8.

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 suppressing warpage of a rolled material in a hot rolling line rough mill rolling mill.

[0002]

2. Description of the Related Art For example, in a conventional method and apparatus for suppressing warpage of a hot-rolled material disclosed in Japanese Patent Application Laid-Open No. Sho 59-1012, the temperatures of the front and back surfaces of a rolled material are measured, According to the relationship between the rotational speed ratio of the upper and lower rolls under load and the front and back surface temperature difference, by setting the rotational speed ratio of the upper and lower rolls based on the actually measured value of the front and back surface temperature difference and starting rolling, the suppression of warpage is suppressed. I do.

[0003]

As described above, the conventional method for suppressing warpage of a hot-rolled material and the apparatus therefor require the use of an expensive thermometer which needs to measure the temperature of the front and back surfaces of the rolled material. In addition to the necessity, there is a problem that an error in the temperature measurement value increases due to the adhesion of the scale to the rolling material and the use environment, thereby causing an error in the command value to the drive device.

[0004]

SUMMARY OF THE INVENTION A method for suppressing warpage of a hot-rolled material according to the present invention comprises the steps of: detecting a warpage of a rolled material rolled by upper and lower rolls with a sensor; Set up the speed ratio of the upper and lower rolls set in the roll speed ratio table in the controller,
The controller controls the upper and lower rolls so that the rotation speed of the upper and lower rolls has the set speed ratio, thereby suppressing the warpage of the rolled material in the next rolling.

Further, in the above method, the degree of warpage of the rolled material is detected by a plurality of sensors, and when a detection signal is received from the plurality of sensors, the upper and lower roll speed ratio table indicates the sheet thickness of the rolled material. The upper and lower roll speed ratios set stepwise for each output of the sensors are set up in the controller.

Further, the curvature of the warpage of the rolled material rolled by the upper and lower rolls is detected by an image sensor, and the upper and lower roll speed ratio for suppressing the warpage is calculated from the thickness of the rolled material and the curvature. The controller is set up, and the controller controls the upper and lower rolls so that the rotational speed of the upper and lower rolls is equal to the set speed ratio, thereby suppressing the warpage in the next rolling.

[0007] Further, an emergency detection sensor is provided for detecting the degree of warpage that is determined to cause the warpage of the rolled material to cause damage to downstream equipment, and the output of the emergency detection sensor is used for the next rolling. The processing is temporarily stopped.

[0008] Further, the device for suppressing warpage of a hot-rolled material according to the present invention is a sensor for detecting the warpage of a rolled material rolled by upper and lower rolls driven by a driving device.
When receiving the output of this sensor, the upper and lower roll speed ratio table to output the upper and lower roll speed ratio according to the thickness of the rolled material to suppress the warpage of the rolled material, and along the speed ratio of the upper and lower rolls It is provided with a controller that controls the driving device so that the upper and lower rolls are driven.

An image sensor for detecting the curvature of the warpage of the rolled material rolled by the upper and lower rolls driven by the driving device. The warpage of the rolled material is determined from the output of the image sensor and the thickness of the rolled material. An upper / lower roll speed ratio calculating device for calculating an upper / lower roll speed ratio to be suppressed, and a controller for controlling the driving device so that the upper and lower rolls are driven along the upper / lower roll speed ratio.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1A is a diagram showing a hot rolling apparatus according to Embodiment 1 of the present invention. In FIG. 1A, 1 is a rolled material, 2 is an upper roll of a rolling mill for rolling the rolled material 1, and 3 is an upper roll 2
, 4 is a lower roll of a rolling mill for rolling the rolling material 1, 5 is a driving device for driving the lower roll 4, 6 is a detecting device for detecting the warpage of the rolling material 1. When the rolled material enters between the light projector provided on one side of the rolled material 1 and the light receiver provided on the other side, the optical sensor detects the material and turns on. Reference numeral 7 denotes an upper / lower roll speed ratio table for determining the speed ratio α _on of the upper and lower rolls based _on the detection state of the optical sensor 6 and the thickness of the rolled material 1. 8 denotes the driving device 3 and the driving device based _{on the} upper and lower roll speed ratio α _on. 5 is a controller for giving a speed command.

Next, the operation will be described with reference to the target roll thickness of the rolled material set in the vertical roll speed ratio table 7 and the vertical roll speed ratio α _on when the sensor is ON, as shown in FIG. 1B. If the rolled material 1 is in an ideal state for rolling, the rolled material 1 rolled by the upper roll 2 and the lower roll 4 does not warp. However, if rolling is not ideal, for example, if the temperature of the rolling material 1 is different between the upper surface and the lower surface, the rolling material 1 may be warped.

The warpage is detected by the optical sensor 6 during rolling of the rolled material 1. When the optical sensor 6 does not detect the rolled material 1, that is, when the warpage has not occurred and the optical sensor 6 is OFF, the speed difference between the upper and lower rolls 2 and 4 is unnecessary, and α _on is all The speed ratio between the upper and lower rolls 2 and 4 is 1 with respect to the target plate thickness. When the rolled material 1 is detected by the optical sensor 6, it is determined that the warpage has occurred,
At the next rolling, using the upper and lower roll speed ratio table 7, the thickness of the rolling material 1 is 0 to T0, T1 to T2, T2 to T3,.
..The speed ratio of the upper and lower rolls α _on0 according to TN
α _on1 , α _on2 ,... α _{on (n + 1)} are set. At the time of the next rolling, a speed command is issued from the controller 8 to the driving device 3 and the driving device 5 according to the speed ratio of the upper and lower rolls as shown in FIG. . When the rolled material 1 is warped, the rotation speed of the upper roll 2 is higher than that of the lower roll 4. The speed ratio increases as the thickness of the rolling material 1 increases.
The values of the upper and lower roll speed ratio table 7 are determined based on the results of adjustment.

Embodiment 2 FIG. Embodiment 2 is a rolling material 1
The speed ratio of the upper and lower rolls can be determined stepwise according to the amount of warpage. In the first embodiment, the upward warpage of the rolled material 1 is detected by the single optical sensor 6, but in the second embodiment, as shown in FIG. A plurality of optical sensors 6 '(sensor 1, sensor 2,
.. Provided with a sensor n), as shown in FIG.
The vertical roll speed ratio α _on for a predetermined target plate thickness is selected according to the optical sensor 6 ′ (sensor 1, sensor 2,... Sensor n) that has detected the rolling material. For example, the sensor 1 is turned on for a plate thickness of 0 to T0.
Then, the upper and lower roll speed ratio is set to α _1on0 and the sensor 2 is _turned on.
Then the upper / lower roll speed ratio is set to α _2on0 and the sensor n
Is _{turned on} , the vertical roll speed ratio is set to α _non0 . Therefore, the speed ratio of the upper and lower rolls can be determined stepwise according to the amount of warpage of the rolled material 1, and more precise control is possible.

Embodiment 3 FIGS. 3 (a) and 3 (b) show a third embodiment in which an emergency detection optical sensor 9 is added to the second embodiment, and the controller 8 is controlled by this detection signal. The emergency detection optical sensor 9 is a sensor that detects the warpage of the rolled material that is larger than expected and that if the rolling is continued as it is, would lead to damage to downstream equipment. When a rolling material is detected by the emergency detection optical sensor 9, a detection signal is applied to the controller 8, and the controller 8 waits for the next rolling by this signal. Other configurations and functions are the same as those of the second embodiment.

Embodiment 4 In the fourth embodiment, as shown in FIG. 4, instead of a plurality of optical sensors 6 ', an image sensor 1 for detecting the amount of warpage of a rolled material as a curvature is used.
An upper / lower roll speed ratio calculating device 11 for calculating an upper / lower roll speed ratio by a calculation formula from the detected curvature and the target plate thickness is provided instead of 0 and the upper / lower roll speed ratio table 7.
Other configurations are the same as those of the third embodiment.

That is, since the upper and lower roll speed ratio is a value proportional to (target thickness of rolled material × 1 / curvature), by calculating the curvature, the upper and lower roll speed ratio is obtained by the calculator 11, and this value is obtained. Set up the controller 8. According to this, it is not necessary to create the upper and lower roll speed ratio tables, and it is possible to more simply and surely suppress the warpage.

[0017]

As described above, according to the present invention, the roll warpage is detected using the sensor, and the roll speed is controlled by referring to the upper and lower roll speed ratio tables. This eliminates the need for an expensive thermometer as in the prior art, enables low-cost, low-curvature warpage suppression.

Further, by arranging a plurality of sensors, the rotation speed control of the upper and lower rolls for suppressing the warpage can be more finely controlled, and more reliable control can be performed.

Further, it is possible to prevent damage to the machinery and equipment, and to facilitate the operator's intervention by automatically setting the rolling to a standby state.

In addition, by directly measuring the curvature of the warpage using an image sensor in a stepless manner, the upper and lower roll speed ratios can be calculated from the amount of the warpage, so that there is no need to create a vertical roll speed ratio table. This makes it possible to suppress warpage, which is more accurate and easy to adjust.

[Brief description of the drawings]

FIG. 1 is a diagram showing an apparatus for suppressing warpage of a hot-rolled material according to Embodiment 1 of the present invention.

FIG. 2 is a view showing an apparatus for suppressing warpage of a hot-rolled material according to Embodiment 2 of the present invention.

FIG. 3 is a view showing a device for suppressing warpage of a hot-rolled material according to Embodiment 3 of the present invention.

FIG. 4 is a view showing a device for suppressing warpage of a hot-rolled material according to Embodiment 4 of the present invention.

[Explanation of symbols]

1 rolled material, 2 upper roll, 3 upper roll drive,
4 Lower roll, 5 Lower roll drive, 6, 6 'light sensor, 7 Upper and lower roll speed ratio table, 8 Controller, 9 Emergency detection optical sensor, 10 Image sensor, 11 Upper and lower roll speed ratio calculation device.

Claims (6)

[Claims] When an upward warpage of a rolled material rolled by upper and lower rolls is detected by a sensor, an upper and lower roll speed ratio set in an upper and lower roll speed ratio table for each sheet thickness of the rolled material is set up in a controller. The controller controls the upper and lower rolls so that the rotation speed of the upper and lower rolls becomes the set speed ratio, thereby suppressing the warpage of the rolled material in the next rolling. A method of suppressing warpage of hot-rolled material. 2. A plurality of sensors detect the degree of warpage of the rolled material, and when a detection signal is received from the plurality of sensors, the upper / lower roll speed ratio table indicates the thickness of the rolled material and the respective sensors. 2. The method according to claim 1, wherein an upper / lower roll speed ratio set stepwise for each output is set up in a controller. 3. An image sensor detects the curvature of the upward warpage of the rolled material rolled by the upper and lower rolls, and calculates an upper and lower roll speed ratio for suppressing the upward warp from the thickness of the rolled material and the curvature. Set up in a controller, by this controller, by controlling the upper and lower rolls so that the rotation speed of the upper and lower rolls is the speed ratio set up, to suppress the warpage in the next rolling. Of warping of hot rolled material. 4. An emergency detection sensor for detecting the degree of warpage of the rolled material, which is determined to cause damage to downstream equipment, and the output of the emergency detection sensor is used for the next rolling. The method for suppressing warpage of a hot-rolled material according to any one of claims 1 to 3, wherein the treatment is temporarily stopped. 5. A sensor for detecting a warpage of a rolled material rolled by upper and lower rolls driven by a driving device,
When receiving the output of this sensor, an upper and lower roll speed ratio table that outputs an upper and lower roll speed ratio according to the thickness of the rolled material so as to suppress the warpage of the rolled material, and an upper and lower roll speed ratio along the upper and lower roll speed ratio. An apparatus for suppressing warpage of a hot-rolled material, comprising a controller that controls the driving device so that the roll is driven. 6. An image sensor for detecting a curvature of an upward warpage of a rolled material rolled by upper and lower rolls driven by a driving device, and detects an upward warpage of the rolled material from an output of the image sensor and a thickness of the rolled material. Upper and lower roll speed ratio calculation device that calculates the upper and lower roll speed ratio to suppress
And a controller for controlling the driving device so that the upper and lower rolls are driven in accordance with the upper and lower roll speed ratios.