JP3321085B2 - Centering method of rolled material - 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 for centering a rolled material, and more particularly to a method for centering a rolled material in which off-center rolling is prevented when centering the rolled material by a side guide.

[0002]

2. Description of the Related Art When a rolled material is rolled by a reversible rolling mill such as a plate rolling mill, sometimes rolling called off-center rolling is performed. The off-center rolling, as shown in FIG. 4, a pair of upper and lower work rolls WR _1, WR ₂ and the backup roll BR _1, rolling mill center of the rolling mill 1 consisting of BR ₂ CL _M and rolled center CL of the rolled material P Rolling is performed in a state where _S does not match and there is a difference in ΔCL, and the rolled material P after rolling has different thicknesses on the left and right sides, which easily causes bending of the plate and causes the side guide to come off. Therefore, there is a problem that rolling stoppage occurs due to equipment damage or the like. Further, since the shape after rolling cannot be made rectangular, it is a factor of yield reduction called bending compensation allowance.

Here, the mechanism of occurrence of sheet bending due to off-center rolling will be described with reference to FIG. If there is a difference between the rolling loads on the work side and the drive side of the rolling mill 1, a difference occurs in the mill elongation between the two. A thickness difference occurs between the work side and the drive side, and the wedge change rate Δψ changes as shown in the following equations (1) and (2).

Δh = h _W −h _D (1) Δψ = (δh / h) − (δH / H) (2) where δh; wedge, h; Outer side plate thickness, H: Inlet side plate thickness, Δ: Wedge ratio. Thereby, bending occurs.

At this time, the meandering model δy and the outgoing bending model k are expressed by the following equations (3) and (4). δy = (α / W) · Δψ (3) k = (K / λ) + (β / W) · Δψ (4) where, W: plate width, K: entry side bending, λ: elongation, α,
β: coefficient.

In order to prevent the above-mentioned bending and meandering from occurring, the rolled material is restrained by a side guide so that the rolled material center and the rolling mill center are aligned with each other before rolling, and the rolled material is centered without fail. Various operation methods have been devised to prevent the occurrence of off-center rolling.

[0007]

However, since centering of a rolled material is conventionally visually checked by an operator, the variation is large and lacks accuracy, and the table is manually operated after the centering is completed. There were problems such as hindering work efficiency.

An object of the present invention is to provide a method of centering a rolled material which solves the above-mentioned problems of the prior art.

[0009]

SUMMARY OF THE INVENTION The present invention provides a method of performing centering of the rolled material using a side guide, the side guide opening speed and the conveyance time of the strip P
Based on (stop position to mill biting time), when the difference between the measured value of the opening degree of the side guide and the plate width falls within a predetermined allowable range, it is determined that centering is completed.
A centering method for a rolled material, characterized in that the entry table is started and automatic operation is started .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred 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 the drawing, the same members as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted. As shown in this figure, an entrance table 2 and an exit table 3 are arranged on the entrance side and exit side of the rolling mill 1, on which the entrance side and exit side guides are provided in close proximity to the rolling mill 1, respectively. 4 and 5 are provided. Here, the configuration of the entry side guide 4 will be described. A pair of left and right guide pieces 4a, 4b are opened and closed by hydraulic cylinders 6a, 6b, respectively. These hydraulic cylinders 6a, 6b
Stroke is the opening of the side guide 4 and the opening meter 7
a, 7b and the hydraulic cylinders 6a, 6
The moving speed of b is detected by the speedometers 8a and 8b as the moving speed of the side guide 4. The entry table 2 is driven by an entry drive motor 9. Further, a plate width meter 10 such as a CCD camera is mounted on the upper part of the entry table 2 of the rolling mill 1.

Reference numeral 11 denotes a lower-level computer, which has a function of controlling the opening degree of the entrance side guide 4, and includes opening degree meters 7a, 7b,
Input the detection signals from the speedometers 8a and 8b and the width meter 10,
The opening degree of the entrance side guide 4 is calculated using the detection signals of the opening degree meters 7a and 7b, and the opening change speed of the entrance side guide 4 is calculated using the detection signals of the speedometers 8a and 8b. Then, the guide piece 4 of the entrance side guide 4 described above.
The hydraulic cylinders 6a and 6b for driving the a and 4b and the entry drive motor 9 of the entry table 2 are controlled, respectively.

Reference numeral 12 denotes a host computer having a function of determining completion of centering of the entrance side guide 4;
The determination signal and other necessary control signals are exchanged with the lower-level computer 11 via the line 13. The function of the host computer 12 will be specifically described with reference to FIG. The host computer 12 determines the change rate V _SG (mm / s) of the opening degree of the side guide, the transport time of the rolled material P (stop position to mill biting time) t (se
Using c), the allowable value of the threshold is calculated by the following equation (5).

Α = V _SG · t (5) Here, the transport time t is calculated from the length of the rolled material P and the transport speed. Then, the side guide opening M is calculated by the following equation (6), and M = W + α W: plate width (6) Then, when the following equation (7) is satisfied, it is determined that the centering is completed. .

M _FBK ≦ M M _FBK : measured value of opening degree of side guide ( actual result ) ... (7) Then, if the above equation (7) is satisfied, it is determined that the centering has been completed and the centering is performed on lower-level computer 11. Outputs a completion signal. Upon receiving the centering completion signal, the lower-order computer 11 immediately activates the entry-side table 2 and performs automatic operation. When the rolled material P is constrained by the side guide 4 and centering is performed, the rolled material P has already advanced, so that the path interval is reduced by that much, and the rolling capacity is improved.

In the above example, the side guide 4 is driven by the hydraulic cylinders 6a and 6b.
The present invention is not limited to this. Needless to say, the same operation can be obtained even when an electric motor or the like is used.

[0016]

EXAMPLES Examples of application of the method of the present invention will be described below. The automatic operation of the method of the present invention was applied to the completion of centering after a spoon turn when rolling a thick rolled material of various sizes with a reverse rolling mill. The results shown in FIG. 3 were obtained for the pass interval time (average value) between the front and rear turns of the rolling mill. For comparison, data of the conventional manual operation is also shown in FIG.

A comparison between the two shows that the difference Δt is about 2.5 sec for front turning and about 5.0 sec for rear turning, indicating that the pass interval time in the automatic operation is reduced. Note that there was no difference between the automatic operation and the manual operation in the off-center ratio and the amount of sheet bending. From this, it is understood that the method of the present invention prevents off-center rolling and reduces time loss that impairs work efficiency.

[0018]

As described above, according to the present invention,
Since the side guide width is set by automatic operation in this way, the off-center rate is comparable to that of manual operation, and the time loss can be reduced by 16.7% to 28.5%, improving productivity. It is clear that this contributes to

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a procedure for determining completion of centering according to the present invention.

FIG. 3 is a characteristic diagram showing the effect of the present invention.

FIG. 4 is an explanatory diagram of a mechanism of occurrence of sheet bending due to off-center rolling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling machine 2 Inlet table 3 Outlet table 4 Inlet side guide 4a, 4b Guide piece 5 Outlet side guide 6a, 6b Hydraulic cylinder 7a, 7b Opening meter 8a, 8b Speedometer 9 Inlet drive motor 10 Plate width Total 11 Lower computer 12 Upper computer 13 Circuits P Rolled material

Claims (1)

(57) [Claims] 1. A method for centering a rolled material using a side guide, comprising: a speed of change of an opening degree of the side guide and a transport time of the rolled material P.
Based on (stop position to mill biting time), when the difference between the measured value of the opening degree of the side guide and the plate width falls within a predetermined allowable range, it is determined that centering is completed.
A centering method for a rolled material, characterized in that the entry table is started and automatic operation is started .