JPH0970754A - Polishing control method of continuous polishing facility of steel plate in coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous polishing control method of a steel plate in coil which can maintain a polished grain of the steel plate in coil uniformly in the longitudinal direction irrespective of wear of a polishing belt. SOLUTION: When surface polishing is done by bringing a polishing belt 1 which is rotated and driven by a contact roll 3 into contact with a surface of a steel plate in coil W and applying polishing pressure on the steel plate in coil W by a billy roll 4 from a rear surface side, changes of a polished grain on a polishing surface on an out side of a polishing device 10 are detected by a polishing grain measurement sensor 11, and at least one of a plurality of polishing conditions which affect the polished grain is automatically controlled in the continuous polishing device 10 by a polishing control device 20 based on the detected value to make the polished grain in the longitudinal direction of the steel plate in coil W uniform. As the polishing conditions, steel plate in coil feed speed, polishing belt peripheral speed, polishing current, breaker angle, offset among of contact roll and billy roll, or the like can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for continuous polishing or grinding (hereinafter referred to as polishing) of a steel strip, and in particular, it is intended to keep the surface quality of the steel strip even during belt polishing. is there.

[0002]

2. Description of the Related Art In general, belt polishing is often used as a method for polishing the surface of a steel strip. Fig. 4 shows the outline of a conventional belt-type steel strip continuous polishing device [3rd Edition Iron and Steel Handbook III (1), Rolling foundation / steel plate, Japan Iron and Steel Institute, P700-701]. That is, the endless ring-shaped polishing belt 21 is attached to the tension roll 22 and the drive motor 2.
The steel strip W is wound around a contact roll 23 that is driven to rotate by means of No. 5, and the steel strip W is fed between the contact roll 23 and a billy roll 24 that moves up and down by hydraulic pressure. A pressure is applied to the surface of the steel strip, and the polishing belt 21 is pressed against the surface of the steel strip while being sprayed with the polishing oil to rotate the surface.

When the surface of the steel strip W is polished in this manner, a polishing stitch is formed on the surface to be polished of the steel strip W according to the number of the polishing belt 21 used. When polishing is continued with the same number of polishing belts, this polishing grain changes in the longitudinal direction of the steel strip as the belt wears. By the way, conventionally, in continuous polishing of a steel strip, it is not particularly performed to automatically control the quality of the polishing surface, and it is determined in advance with respect to the change in the polishing grain due to the wear of the polishing belt. The polishing apparatus is operated by visually assessing whether or not the polishing stitches within a predetermined range are obtained.

[0004]

In the conventional quality control in steel strip polishing, the upper limit (fine) and the lower limit (coarse) of the polishing grain are set as described above, and the polishing grain falls within the range. As described above, the judgment is made visually, and the polishing belt is exchanged with a new one when it is out of the set range.

However, even in the case of product steel strips which are judged to be the polishing stitches within the set range by this method and are regarded as acceptable products, before and after the replacement of the polishing belt, those near the upper limit value and those near the lower limit value come close to each other. There is a possibility that the product manufactured by cutting and cutting it and shipped as a steel plate product may be used, for example, arranged side by side on a roof or a wall surface. In this way, when the one with the polishing grain close to the upper limit and the one with the polishing grain close to the lower limit are used side by side, the length of the polishing grain, the degree of fineness, etc. are proportional to the gloss, and therefore both polishing grain However, there was an unsolved problem that the difference between the two would appear as an apparent difference, which would often lead to a decrease in product value.

Further, since the visual evaluation of the polishing eyes is carried out visually as compared with the upper limit sample board and the lower limit sample board, there is also a problem that variations in the polishing eyes are likely to be large. Therefore, the present invention has been made by paying attention to such unsolved problems of the conventional techniques, and it is possible to uniformly maintain the polishing stitches of the steel strip in the longitudinal direction regardless of the wear of the polishing belt. It is an object of the present invention to provide a method for controlling continuous polishing of a steel strip which can be performed.

[0007]

In order to achieve the above object, the invention according to claim 1 makes a polishing belt, which is rotationally driven by a contact roll, contact the surface of a steel strip and a billy roll from the back surface side. A control method for controlling the polishing state of a continuous polishing device for a steel strip, which carries out surface polishing while applying a polishing pressure to the steel strip, wherein a change in the polishing grain of the polishing surface on the outlet side of the polishing device is detected, Based on the detected value, at least one of a plurality of polishing conditions affecting the polishing grain is adjusted to make the polishing grain in the longitudinal direction of the steel strip uniform.

In the invention according to claim 2, the plurality of polishing conditions according to claim 1 are steel strip feeding speed, polishing belt peripheral speed, polishing current, breaker angle, steel strip feeding of the contact roll and billy roll. The amount of offset in the direction (offset amount) is used to adjust at least one of the polishing conditions. The inventors of the present invention, as factors that cause changes in the polishing stitches that occur during belt polishing of the surface of a steel strip, are not limited to wear of the polishing belt, but also peripheral velocity of the polishing belt, line speed (feed rate of the steel strip). , Polishing current,
We paid attention to the breaker angle and the change in the offset amount between the contact roll and the billy roll. That is, as the peripheral speed of the polishing belt is increased, the line speed is decreased, the polishing current is decreased (that is, the polishing pressure of the billy roll is decreased), the breaker angle is increased, and the contact roll and billy roll are separated. The smaller the offset amount of, the shorter the length of the polishing mesh. Therefore, at least one of these factors is set as a control target, and the polishing length of the steel strip is feedback-controlled.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, the structure will be described. In the continuous strip polishing apparatus 10 for a steel strip of the present embodiment, an endless polishing belt 1 is wound between an idle roll 2 and a contact roll 3. Both ends of the idle roll 2 are supported by hydraulic cylinder devices (not shown) so as to be able to move up and down to adjust the tension of the polishing belt 1. The contact roll 3 is structured to rotate the polishing belt 1 by a rotation drive motor (not shown) connected to one end side,
The peripheral speed of the polishing belt 1 is adjusted by controlling the rotation speed of the rotary drive motor.

Below the contact roll 3, a billy roll 4 which is moved up and down by hydraulic pressure is disposed, and a steel strip W of a material to be polished is pressed against the contact roll 3 to apply a polishing force. The polishing force can be changed by raising and lowering the billy roll 4, but the change in the polishing force is caused by a current (polishing current) of a rotation driving motor (not shown) that rotationally drives the contact roll 3.
Therefore, the polishing current can be actually detected to control the polishing force.

Breaker rolls 5 and 6 are installed on the steel strip entry side and the billy roll exit side of the billy roll 4, respectively.
The required tension is applied to. Steel strip W that is sent to billy roll 4 by displacing breaker roll 5 up and down
It is possible to adjust the tension of the steel strip W by adjusting the approach angle, that is, the size of the breaker angle α.
The contact area between the steel strip W and the polishing belt 1 can be changed.

Further, the contact roll 3 and the billy roll 4 can be offset by shifting the axial center in the front-back direction (steel strip feeding direction), and the contact roll by the billy roll 4 can be adjusted by adjusting the offset amount OF. It is possible to change the pressing position to the position 3. As shown in FIG. 1, the continuous polishing apparatus 10 includes a polishing eye measurement sensor 11 for detecting a change in a polishing eye on a surface to be polished of a steel strip on the outlet side of the continuous polishing apparatus 10, and a detection value thereof. On the basis of the above, a polishing control device 20 for adjusting at least one of a plurality of polishing parameters (described later) regarding the polishing stitches of the continuous polishing device 10 to make the polishing stitches in the longitudinal direction of the steel strip W uniform is installed.

The polishing eye measuring sensor 11 is, for example, a CC
D, a laser beam or the like is used to output a detection signal which detects a change in optical characteristics such as gloss of the polished surface of the steel strip. The polishing control device 20 receives the output signal of the polishing eye measurement sensor 11 and converts it into a polishing eye signal K and outputs it, and a polishing eye signal and a polishing eye pattern setting of this polishing eye converter 12. And a control signal corresponding to the polishing eye change amount ΔK in response to the calculation result of the polishing eye change amount arithmetic unit 13 To the continuous polishing apparatus 10. In the polishing pattern setting device 15, polishing pattern information determined in accordance with the required quality of the product steel strip W, the number of counts of the polishing belt 1 used, etc. is preset.

Next, the polished eye measuring sensor 1 of the present embodiment example
A method of controlling the operation of the continuous polishing device 10 by the No. 1 and the polishing control device 20 to achieve uniform polishing of the steel strip W will be described. First, in the belt polishing of the surface of the steel strip, as factors that cause changes in the polishing eyes, in addition to the consumption of the polishing belt, the peripheral speed of the polishing belt, the line speed, the polishing current, the breaker angle, the contact roll and the billy roll It has been described that there is a change in the offset amount OF (hereinafter, simply referred to as "roll offset amount"). FIG.
(A) to (e) qualitatively represent the relationship between these factors and the polishing stitch length. (A) The line speed and the polishing stitch have an upward-sloping relationship.
The faster the feeding of the steel strip W, the longer the contact distance between the polishing belt 1 and the steel strip W, and as a result, the longer the polishing stitch becomes. (B) The peripheral speed of the belt and the grind are in a downward sloping relationship. The peripheral speed of the polishing belt 1 (that is, the contact roll 3
The slower the rotation speed), the longer the contact time between the polishing belt 1 and the steel strip W, and the longer the polishing length becomes. (C) The polishing current and the polishing stitch have an upward-sloping relationship. As the billy roll 4 is raised to increase the polishing current of the contact roll drive motor, the polishing pressure increases, and as a result, the polishing stitch becomes deeper and longer. (D) The breaker angle α and the grind have a downward sloping relationship. Raise breaker roll 5 and breaker angle α
Is smaller, the contact area between the polishing belt 1 and the steel strip W is larger, and as a result, the polishing stitch is longer. (E) The roll offset amount OF and the polishing stitch have an upward-sloping relationship. The larger the misalignment between the contact roll 3 and the billy roll 4, the larger the contact area between the polishing belt 1 and the steel strip W, resulting in a longer polishing grain.

In the present embodiment, the above relationship is used to control the polishing eyes. Idle roll 2 of continuous polishing device 10
The new polishing belt 1 is mounted between the contact roll 3 and the contact roll 3, and the steel strip W is provided between the polishing belt 1 and the billy roll 4.
The steel strip W with the breaker angle α applied by the front and rear breaker rolls 5 and 6 to tension the steel strip W.
Is continuously fed while being fed at a predetermined feeding speed. The surface to be polished of the polished steel strip W is scanned by the polishing eye measurement sensor 11 to detect the polishing eye one by one. This detection signal is sent to the polishing stitch converter 12 in the polishing control device 20 and converted into the polishing stitch signal K. The polishing stitch signal K is input to the polishing stitch variation amount calculator 13.

The polishing stitch change amount calculator 13 outputs the polishing stitch signal K and the output signal of the polishing stitch pattern setting device 15 to which the polishing stitch pattern information previously determined for each steel strip product is input (polishing stitch pattern setting information). The target value of the polishing is calculated as a deviation from the target value, and if ΔK is positive, the polishing length is too short, and if it is negative, the polishing length is long. If it is too much, the result of calculation corresponding to the excess or deficiency is output to the polishing controller main body 14. The polishing control device body 14 feedback-controls the polishing conditions in the continuous polishing device 10 so as to compensate the excess or deficiency of the polishing stitch length based on the input polishing stitch variation amount ΔK. In that case, the polishing conditions to be controlled include the peripheral speed of the polishing belt, the line speed, the polishing current, the breaker angle α, and the roll offset amount OF.
Of these, at least one is selected.

FIG. 3 shows an aspect of polishing control of the present embodiment in comparison with the case of the conventional continuous polishing apparatus 10. That is, conventionally, polishing is performed while maintaining the above polishing conditions constant. When the polishing belt 1 is new, the length of the polishing mesh is longest, and as the polishing belt 1 is gradually worn, the length of the polishing mesh becomes shorter. A visual evaluation is performed by comparing the change in the polishing marks with a reference sample, and when the polishing marks reach the upper limit of wear, which is the shortest in the allowable range, the belt is replaced, and the polishing operation using a new belt is performed again. Was going on. Therefore, it is inevitable that upper and lower steps are generated in the polished steel strip before and after the replacement of the polishing belt.

On the other hand, in the present embodiment, the polishing stitch measuring sensor 11 constantly detects the polishing stitches on the polishing surface of the steel strip W, and the above-mentioned polishing conditions are determined in accordance with the excess or deficiency of the preset polishing stitches. At least one is feedback controlled. For example, assuming that the breaker angle α is selected as the polishing condition, the breaker roll 5 is gradually raised as the polishing progresses, and the breaker angle α is controlled to decrease (to the lower right). The contact area with W is gradually increased to lengthen the polishing eye. In this way, the shortening of the polishing stitch length with time is canceled out, and as a result, the polishing stitches of the product steel strip can be kept substantially constant by substantially matching the center value of the allowable range. When the size of the breaker angle α reaches a preset limit, the polishing belt 1
Are replaced and the operation of the continuous polishing apparatus 10 is continued under the above control. Therefore, a certain amount of polishing can be obtained before and after the replacement of the polishing belt 1.

Even when polishing conditions other than the breaker angle α are selected as objects to be controlled in the continuous polishing apparatus 10, the same effects can be achieved by following the above procedure. Of course, it is also possible to select and control a plurality of polishing conditions. In the description of the above-described embodiment, the polishing mesh length is used as the variation amount (ΔK) of the polishing mesh, but other than the length,
The parameters such as the width and depth of the grind may be used as the grind, and in this case, the grind more uniform in the longitudinal direction of the product can be obtained.

Further, when the line speed is selected as one of the polishing conditions, the control in the direction of decreasing the line speed undesirably lowers the productivity.
As is clear from the above, in the continuous polishing control method of the present invention, the line speed can be increased to cope with the change in the polishing stitches (shortening of the polishing stitches) due to the consumption of the polishing belt, and therefore the productivity can be improved. There is no fear of deterioration.

[0021]

As described above, according to the present invention,
According to the change of the polishing grain of the polishing surface on the output side of the polishing apparatus, at least one of a plurality of polishing conditions affecting the polishing grain is automatically controlled to make the polishing grain in the longitudinal direction of the steel strip uniform. As a result, it becomes possible to make the polishing stitches of the steel strip uniform in the longitudinal direction, and this makes it possible to eliminate erroneous determinations and variations due to visual determination of the polishing stitches, eliminating the problem of polishing stitches changing due to abrasion of the polishing belt. It has the effect of increasing the product value.

Further, there is an effect that it is possible to promptly respond to the demand for the polishing stitches according to the demand only by inputting the polishing pattern.

[Brief description of drawings]

FIG. 1 is a control block diagram of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing the effect of each polishing condition of the polishing apparatus on the polishing stitch length.

FIG. 3 is a diagram showing an aspect of a control method of the present invention in comparison with a conventional one.

FIG. 4 shows an example of a main part structure of a conventional belt-type steel strip surface polishing apparatus, in which (a) is a front view and (b) is a side view.

[Explanation of symbols]

 1 Polishing Belt 3 Contact Roll 4 Billy Roll 5 Breaker Roll 10 Continuous Polishing Device 11 Polishing Eye Measurement Sensor 12 Polishing Eye Converter 13 Polishing Eye Change Calculator 14 Polishing Control Device Main Body 15 Polishing Eye Pattern Setting Device 20 Polishing Control Device

Claims (2)

[Claims] 1. A continuous strip polishing equipment for a steel strip, wherein a polishing belt rotatably driven by a contact roll is brought into contact with the front surface of the steel strip, and a billy roll is applied to the steel strip from the rear surface while polishing pressure is applied to the steel strip. A control method for controlling a polishing state, which detects a change in a polishing grain on a polishing surface on the outlet side of the polishing apparatus, and adjusts at least one of a plurality of polishing conditions that affect the polishing grain based on the detected value. A method for controlling continuous polishing of a steel strip, characterized in that the longitudinal polishing of the steel strip is made uniform. 2. The plurality of polishing conditions are steel strip feed rate,
A polishing belt peripheral speed, a polishing current, a breaker angle, and a shift amount (offset amount) in the steel strip feeding direction between the contact roll and the billy roll.
A continuous polishing control method for a steel strip as described.