JPH0118807B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applied to the rolling of H-shape, I-shape, channel steel, etc. by adjusting the roll gap amount of the finishing universal rolling mill during rolling. This invention relates to a method for controlling plate thickness.

(Prior technology) Shape steel rolling involves continuously rolling steel material extracted from a heating furnace using a rough rolling mill, an intermediate rolling mill, and a finishing mill that are arranged in series to produce products with predetermined product dimensions. It is something to do. The length of the product rolled by a finishing mill for continuous rolling is 240 m, and a temperature drop (thermal rundown) of approximately 20°C occurs at the leading and trailing ends due to the rolling time. Due to this temperature drop, the deformation resistance of the steel material increases as it goes toward the rear end even within the same bar, and the finished thickness of the product increases from the front end to the rear end, resulting in a disadvantage that the products do not have the same dimensions. Several documents have been published regarding thickness control of conventional section steel. For example, in Japanese Patent Laid-Open No. 50-84447, the thickness of the web portion and left and right flange portions is measured using a thickness gauge, and the rolling reaction force and roll gap of the horizontal roll and left and right vertical rolls are measured using a load cell and a gap measuring device, respectively. Based on these measured values, the thickness of each part is calculated using Hook's law, taking into account the influence between the web and the left and right flanges, and the thickness of the horizontal roll and left and right vertical rolls is calculated based on the deviation from the target value. Techniques for controlling the amount of reduction are known. This method does not take temperature changes due to thermal rundown into consideration, and the control technology is also complicated.

(Purpose of the Invention) The present invention aims to improve the yield by eliminating as much as possible dimensional variation from the leading end to the trailing end of the product, as the demand for improving the yield has become even more severe in recent years, and also to achieve uniform plate thickness in the longitudinal direction. The purpose is to manufacture products using a simple roll gap control method.

(Summary of the Invention) The plate thickness control method of the present invention to achieve the above object is to control the roll gap of the final stage universal rolling mill of a section steel finishing mill train using a metal-in signal of the final stage rolling mill. Start counting, and calculate L/P from the distance L between the final universal rolling mill and the final pre-rolling mill and the number of pulses P.
The length of the section steel to be rolled out from the final stage universal rolling mill is determined from the L/P and the metal-in signal of the final stage universal rolling mill, and the length of the rolled steel is compared with the set rolling start distance. When the comparison values match, the horizontal roll and vertical roll gap adjustment amounts are calculated from the stepping length and the set horizontal roll and vertical roll gap tightening amount per unit distance, and the final stage universal rolling mill is adjusted based on the calculated values. A method for controlling horizontal roll and vertical roll gap amounts by driving the horizontal roll and vertical roll reduction devices of Determine the roll circumferential speed of the horizontal roll or vertical roll, and by the metal-in signal of the final stage universal rolling mill, multiply the roll circumferential speed by the value of the time counter to calculate the length of the section steel to be rolled out from the final stage universal rolling mill. is calculated, the start-up length and the set rolling start distance are compared, and when the comparison values match, the horizontal roll and vertical roll gap are determined from the start-up length and the set horizontal roll and vertical roll gap tightening amount per unit distance. A method for controlling the horizontal roll and vertical roll gap amounts by calculating a vertical roll gap adjustment amount and driving the horizontal roll and vertical roll reduction device of a final stage universal rolling mill based on the calculated value, and a section steel finishing rolling mill row In order to control the roll gap of the final stage universal rolling mill, a length gauge is installed near the exit side of the final stage universal rolling mill, and the length of the section steel rolled out from the final stage universal rolling mill is measured by the length gauge. Compare and calculate the start-up length and the set rolling start distance, and when the comparison values match, determine the horizontal roll and vertical roll gap from the start-up length and the set horizontal roll and vertical roll gap tightening amount per unit distance. The present invention is a method for controlling the horizontal roll and vertical roll gap amounts by calculating the roll gap adjustment amount and driving the horizontal roll and vertical roll reduction devices of the final stage universal rolling mill based on the calculated value.

(Structure of the Invention) The present invention will be described in detail below based on illustrated embodiments.

Figure 1 shows a cross-sectional view of an H-section steel, which is a typical section steel. In the figure, A shows the web part and B shows the flange part. FIG. 2 shows the layout of a typical finishing rolling mill, where E indicates an edger rolling mill and U indicates a universal rolling mill. Subscripts 4 and 5 are used to distinguish them from each other. The rolling mills U6 and U7 in the same figure are stands subject to plate thickness control for implementing the method of the present invention.
The U6 rolling mill is the final stage rolling mill, and the final stage rolling mill U7 is the final stage rolling mill. FIG. 3 is an electrical block diagram showing an embodiment of the first invention of the present invention. 1 is a metal-in signal indicating that the tip of the section steel of the U6 rolling mill is bitten;
2 is the metal-in signal indicating that the tip of the section steel is caught in the U7 rolling mill, 3 is the pulse generator (PLG) attached to the horizontal roll of the U6 rolling mill,
4, 4' and 15, 16 are AND circuits, and 5 is a counter for calculating L/P. 6 is a multiplier that calculates the length of the section steel rolled out from the U7 rolling mill, 7 is a comparator that compares the set rolling start distance (n・Δl) 8 with the value of the multiplier 6, and 9 is the U7 rolling mill. 10 is a gap control amount calculation device for the vertical rolls of the U7 rolling mill, 11 is a horizontal roll gap tightening amount signal per set unit distance, and 12 is a vertical roll gap per set distance. Tightening amount signal, 13 is horizontal roll reduction APC (automatic position control) device, 14 is vertical roll reduction APC, 17 is U
7 is a flange width gauge installed on the exit side of the rolling mill to measure the flange width of the shaped steel, 18 is a comparator, and 19 is a metal-off signal when the rear end of the shaped steel has passed through the U7 rolling mill. Further, SET indicates a set signal, and RST indicates a reset signal.

(Action of invention) The effect based on the above configuration will be described.

When the tip of the material to be rolled gets caught in the U6 rolling machine, the U
From the metal-in signal 1 of rolling mill 6,
Until the PLG3 starts counting and the U7 rolling mill metal-in signal 2 turns ON, the counter 5 calculates the count number P of the output pulses of the PLG3 corresponding to the distance L between the U6 rolling mill and the U7 rolling mill through the AND circuit 4. , Increment L/P (min/pulse)
seek. If this L/P is multiplied by the count value of the output pulse of PLG3 from the metal-in signal 2 of the U7 rolling machine when the tip of the rolled material obtained through the AND circuit 4' is bitten by the U7 rolling mill, the steel Find the length of the steel material after it is bitten by the U7 rolling mill. A comparator 7 compares the steel material length with the rolling start distance (Δl) 8 set by the operator, and when they become the same, rolling of the horizontal rolls and vertical rolls is started. The reduction amount at this time can be determined by multiplying the length of the steel material by the horizontal roll and vertical roll values 11 and 12 of the roll gap tightening amount per unit distance set by the operator in advance. And the roll gap adjustment amount of the vertical roll is determined, and each is outputted to the horizontal roll reduction APC 13 and the vertical roll reduction APC 14, and the respective reduction motors are driven to control the horizontal roll gap amount and the vertical roll gap amount. This operation is performed every n times Δl.
When the rolled material whose thickness is controlled in this way passes through the flange width meter 17 installed at the rear of the U7 rolling mill, the difference by flange width is α (here, α<0)
If the value is reached, the control shall be stopped and the previous value shall be held. The end timing of plate thickness control is the U7 rolling mill metal off signal 19 when the rear end of the rolled material passes through the U7 rolling mill, and when signal 19 is turned off, the horizontal roll rolling APC 13 vertical roll rolling APC
14 is reset by AND circuits 15 and 16, the horizontal rolls and vertical rolls of the U7 rolling mill are returned to their initial roll gap values, and the next steel material is waited for. In this example, the U6 rolling mill was used as the final front stage rolling mill, but it can also be carried out using an E4 edger rolling mill.

FIG. 4 shows another embodiment in which the rolling length is determined from the circumferential speed of the roll.

When the metal-in signal 2 of the final stage universal rolling mill U7 is obtained, the preset roll diameter value (mm) 41 and the final stage universal rolling mill U
The value (rev/sec) of the tachometer 40 installed on the horizontal roll (or vertical roll) of No. 7 is calculated by the multiplier 43, and the time counter 44 is further multiplied by the multiplier 46, so that the shape steel is in the final stage. A rolling length obtained by the universal rolling mill U7 is obtained. The comparator 7 compares this rolling length with the preset rolling timing 8, and when they match, a rolling command is output to the horizontal roll rolling device and the vertical roll rolling device, and the horizontal roll of the final stage universal rolling mill U7 is The plate thickness is controlled by driving vertical rolls. The arithmetic circuits after the comparator 7 are the same as those shown in FIG. 3, and illustration and description thereof will be omitted. FIG. 5 shows yet another embodiment in which the rolled length is determined using a length meter. The final stage universal rolling mill U7 receives a signal 51 from the tip detector 52 installed on the exit side of the final stage universal rolling mill U7.
The rolling length of the section steel to be bitten is determined, the rolling length is compared with the preset rolling timing 8 using a comparator 7, and when the two match, the horizontal roll rolling device of the final stage universal rolling mill U7, The plate thickness is controlled by outputting a rolling down command to the vertical roll rolling down device and driving the horizontal roll and vertical roll. The arithmetic circuits after the comparator 7 are the same as those shown in FIG. 3, and illustration and description thereof will be omitted. or,
When this plate thickness control method is used for a grooved roll row instead of a universal rolling mill row, the web portion becomes the control target.

(Example) The rolling start distance Δl was set to 20 m, the horizontal roll gap control was set to 0.15 mm/120 m, and the vertical roll gap control amount was set to 0.2 mm/120 m to control the plate thickness (using the method shown in Figure 3). However, the temperature difference between the leading edge and the trailing edge was 20°C, but the plate thickness difference between the leading edge and the trailing edge was 0.1.
m/m, significantly improving dimensional accuracy compared to the conventional model, which had a maximum of 0.4 m/m.

(Effects of the Invention) The plate thickness control method of the present invention significantly reduces dimensional fluctuations in plate thickness and improves product yield by about 0.5%, which is a significant effect.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an H-section steel product, FIG. 2 is an explanatory diagram showing the layout of a finishing rolling mill, and FIGS. 3 to 5 are block diagrams showing embodiments of the present invention. In the drawing, A is the web part of the H-shaped steel product, B is the flange part, U is the universal rolling mill, E is the Edger rolling machine, 1 is the U6 mill metal-in signal, and 2 is the U
7 mil metal in signal, 3 is U6 mil PLG, 4,
4' is an AND circuit, 5 is a counter, 6 is a multiplier,
7 is a comparator, 8 is a rolling start distance, 9 is a horizontal roll roll gap control amount calculation device, 10 is a vertical roll roll gap control amount calculation device, 11 is a horizontal roll gap control amount per unit length of steel material of the horizontal roll, and 12 is a horizontal roll gap control amount calculation device. Vertical roll gap control amount per unit length of vertical roll steel material, 13 is horizontal roll reduction APC,
14 is a vertical roll reduction APC, 15 and 16 are AND circuits, 17 is a flange width meter, 18 is a comparator, 19
is the U7 mil metal off signal.

Claims (1)

[Scope of Claims] 1. In controlling the roll gap of the final stage universal rolling mill in the section steel finishing mill row, pulse counting is started by the metal-in signal of the final pre-stage rolling mill, and the final stage universal rolling mill and the final pre-stage rolling mill are Determine L/P from the distance L between the rolling mills and the number of pulses P, determine the length of the shaped steel to be rolled out from the final universal rolling mill from the L/P and the metal-in signal of the final universal rolling mill, Compare and calculate the start length and the set rolling start distance, and when the comparison values match, the horizontal roll and vertical roll gap adjustment amount is determined from the step length and the set horizontal roll and vertical roll gap tightening amount per unit distance. A method for automatically controlling the thickness of a section steel, comprising: calculating the calculated value, and driving the horizontal roll and vertical roll reduction devices of the final stage universal rolling mill based on the calculated value to control the horizontal roll and vertical roll gap amounts. . 2. When controlling the roll gap of the final stage universal rolling mill of the section steel finishing mill row, determine the roll peripheral speed of the horizontal roll or vertical roll of the final stage universal rolling mill, and use the metal-in signal of the final stage universal rolling mill, Multiplying the circumferential speed of the roll by the value of the time counter to determine the length of the section steel rolled out from the final stage universal rolling mill, and comparing and calculating the length of rolled-out steel with the set rolling start distance,
At the time when the comparison values match, the horizontal roll and vertical roll gap adjustment amounts are calculated from the draw-out length and the set horizontal roll and vertical roll gap tightening amounts per unit distance, and the final stage universal rolling mill is adjusted based on the calculated values. 1. A method for automatically controlling the thickness of a sectioned steel sheet, the method comprising: controlling the gap amount of the horizontal rolls and the vertical rolls by driving the horizontal roll and vertical roll reduction devices. 3. In order to control the roll gap of the final stage universal rolling mill in the section steel finishing mill row, a length gauge is installed near the exit side of the final stage universal rolling mill, and the length gauge measures the roll gap from the final stage universal rolling mill. Find the length of the section steel, compare the length of the cut-out with the set rolling start distance, and when the comparison values match, determine the length of the horizontal roll and vertical roll gap tightening per unit distance set as the length of the comparison. The horizontal roll and vertical roll gap adjustment amounts are calculated based on the calculated values, and the horizontal roll and vertical roll reduction devices of the final stage universal rolling mill are driven to control the horizontal roll and vertical roll gap amounts. Automatic plate thickness control method for section steel.