Method and device for improving positioning accuracy of a steel taking machine of a heating furnace

Abstract

The application discloses a method and device for improving positioning accuracy of a steel taking machine of a heating furnace, and belongs to the technical field of hot-rolling heating furnaces. The method is implemented by refining C values in a mathematical model of the steel taking machine of the hot-rolling heating furnace, obtaining C values of slabs of various widths, and determining advancing or retreating APC strokes of the steel taking machine. The mechanical inertia of the equipment when the steel taking machine is stopped is improved through PLC, so that the steel taking machine is positioned. The slabs of various widths are debugged and functionally improved, so that the positioning accuracy of the steel taking machine can be directly quantified. The application can improve the position accuracy of the steel taking machine and solve a series of problems such as steel spreading and deviation of the heating furnace.

Description

Technical Field

[0001] This invention belongs to the field of hot rolling heating furnace technology, and more specifically, relates to a method and apparatus for improving the positioning accuracy of the steel tapping machine in a heating furnace, which is applied in a hot rolling plate production line. Background Technology

[0002] The heating furnace area of ​​a hot rolling mill is responsible for loading, heating, unloading, and transporting slabs to the rolling line for rolling. Figure 1 As shown, the forward and backward movement of the steel take-up machine is electrically controlled, while the lifting is hydraulically controlled. The slab is loaded at the charging end and transported to the discharge end by a walking beam. When the slab reaches the discharge end and is detected by the laser detector on the furnace side, the steel take-up machine extracts the slab from the furnace and places it on the C-TBL (Cell-to-Board Roller). The C-TBL then transports the slab to the main rolling line for rolling. The process is controlled by a single-level controller, and the numerical control model is imported from SMS Group.

[0003] In recent years, due to the continuous increase in product specifications, the length and width of heated slabs have increased, and the width difference between slabs has become increasingly significant. In particular, the production capacity of high-temperature HIB (high-temperature HIB) furnaces has increased rapidly. Because high-temperature HIB furnaces cause severe bending of the slabs inside the furnace, the positioning accuracy requirements for the forward and backward movements of the steel tapping machine in the heating furnace have become increasingly stringent. Under these production conditions, the deficiencies in the original design of the steel tapping machine's control principle have gradually become apparent. The most prominent problems are as follows:

[0004] (1) When the steel taker is drawing slabs with a width of 1500mm or more, due to defects in the original mathematical model and program for the steel taker's retraction, the steel taker cannot automatically return the slab to the center line of the C-roller. This causes the slab to rest on the C-roller bearing seat, resulting in steel spreading. Operators are forced to manually operate the steel taker to adjust the position of the slab on the roller, thus slowing down the rolling rhythm of the entire rolling line and severely affecting the production capacity. At the same time, if the operator makes a slight mistake, it will cause a major equipment accident such as the slab derailing. Figure 2 As shown.

[0005] (2) When the steel taker is taking out slabs with a width of 1050mm or less, the automatic forward stroke of the steel taker is too large, causing the second slab on the furnace side to be lifted up. If the steel taker moves backward at this time, it will drag the second slab off course in the furnace, or even cause a major equipment accident where the second slab falls into the furnace. This will force the heating furnace to stop and retrieve the steel.

[0006] (3) Because the steel take-out machine cannot place the slab on the center line of C-TBL after it is pulled out, the slab will deviate on C-TBL, causing great damage to the guard plate of C-TBL. If the roughing mill VSB side guide plate cannot operate normally and slab centering is carried out at this time, it will have a huge impact on the steel feeding of the roughing mill VSB, seriously threatening the safe operation of the roughing mill VSB, and even causing the roughing mill VSB to be unable to feed steel, thus causing the entire main rolling line to stop production.

[0007] Therefore, improving the positioning accuracy of the steel tapping machine in the heating furnace is a technical problem that urgently needs to be solved. Summary of the Invention

[0008] To address the inherent design flaws in the original numerical model introduced by SMS, a positioning method and device for the steel tapping machine in the heating furnace is proposed to improve its positioning accuracy and solve a series of problems such as steel spreading and deviation in the heating furnace.

[0009] To achieve the above objectives, according to one aspect of the present invention, a method for improving the positioning accuracy of a steel tapping machine in a heating furnace is provided, comprising:

[0010] The C value in the mathematical model of the steel tapping machine of the hot rolling heating furnace is refined to obtain the C value for various widths of slabs, so as to determine the forward or backward APC stroke of the steel tapping machine;

[0011] The mechanical inertia of the steel take-up machine is improved by using a PLC when it stops moving forward or backward, so as to position the steel take-up machine.

[0012] The functions of slabs of various widths were adjusted and improved so that the positioning accuracy of the steel taking machine could be directly quantified.

[0013] In some alternative implementations, the refinement of the C-value in the mathematical model of the hot-rolling furnace tapping machine to obtain C-values ​​for various slab widths includes:

[0014] Through actual production processes and experiments during shutdowns, the forward and backward travel of various slab widths was measured on-site to obtain the C-value for various slab widths.

[0015] In some alternative implementations, the C value is 140mm when the slab width is <950mm; 150mm when the slab width is ≤1000mm; 175mm when the slab width is ≤1100mm; 195mm when the slab width is ≤1210mm; 215mm when the slab width is ≤1350mm; 275mm when the slab width is ≤1500mm; 300mm when the slab width is ≤1550mm; and 315mm when the slab width is 1550mm.

[0016] In some alternative implementations, the step of improving the mechanical inertia of the steel reclaimer when it stops moving forward or backward using a PLC to position the steel reclaimer includes:

[0017] Depend on After receiving the command to stop the steel taker in either forward or backward movement, the steel taker speed value Vx is given. Lx is the actual position error detected by the encoder, Acc is the deceleration of the transmission when it stops, Lcd is the crawling distance, and Ldd is the transmission delay distance.

[0018] limit When |Lx|≤Lde, the output Vx=0, Vc is the crawling speed, Vm is the maximum speed, and Lde is the sliding distance after issuing the stop command from the crawling speed.

[0019] In some alternative implementations, Td is the transmission delay time.

[0020] According to another aspect of the present invention, an apparatus for improving the positioning accuracy of a steel tapping machine in a heating furnace is provided, comprising:

[0021] The C-value refinement module is used to refine the C-value in the mathematical model of the steel tapping machine in the hot rolling furnace, and obtain the C-value for various widths of slabs to determine the forward or backward APC stroke of the steel tapping machine.

[0022] The PLC module is used to improve the mechanical inertia of the steel take-up machine when it moves forward or backward and stops, so as to position the steel take-up machine.

[0023] The debugging module is used to debug and improve the functions of slabs of various widths, so that the positioning accuracy of the steel taking machine can be directly quantified.

[0024] In some optional implementations, the C-value refinement module is used to actually measure the forward and backward strokes of various slab widths on-site through experiments during actual production processes and shutdowns, and to obtain the C-values ​​for various slab widths.

[0025] In some alternative implementations, the C value is 140mm when the slab width is <950mm; 150mm when the slab width is ≤1000mm; 175mm when the slab width is ≤1100mm; 195mm when the slab width is ≤1210mm; 215mm when the slab width is ≤1350mm; 275mm when the slab width is ≤1500mm; 300mm when the slab width is ≤1550mm; and 315mm when the slab width is 1550mm.

[0026] In some alternative implementations, the PLC module is used by... After receiving the command to stop the steel take-up machine in either forward or backward direction, the speed value Vx of the steel take-up machine is given. Lx is the actual position error detected by the encoder, Acc is the deceleration of the transmission stopping, Lcd is the creep distance, and Ldd is the transmission delay distance; Limitation When |Lx|≤Lde, the output Vx=0, Vc is the crawling speed, Vm is the maximum speed, and Lde is the sliding distance after issuing the stop command from the crawling speed.

[0027] In some alternative implementations, Td is the transmission delay time.

[0028] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0029] This invention achieves high positioning speed and accuracy by refining the C-value and improving the positioning of the steel take-off machine in the heating furnace. It completely solves the problem of positioning accuracy in the forward and backward positions of the steel take-off machine in the heating furnace. This plays a significant role in maximizing the production capacity of hot rolling mills and preventing major equipment accidents. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the layout of a heating furnace process equipment provided in an embodiment of the present invention;

[0031] Figure 2 This is a comparative schematic diagram of the positioning of a slab on C-TBL provided by an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the principle of an APC setpoint model for a steel taking machine provided in an embodiment of the present invention;

[0033] Figure 4 This is a stroke diagram of a steel taking machine provided in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of a method for improving the positioning accuracy of a steel tapping machine in a heating furnace, provided by an embodiment of the present invention.

[0035] Figure 6 This is a schematic diagram of a positioning method for a steel take-off machine in a heating furnace provided in an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0037] The following is a detailed analysis of the defects in the original mathematical model of the steel taking machine.

[0038] (1) The original APC setting value model of the steel tapping machine has serious defects:

[0039] The principle of the original steel tapping machine APC setpoint model is as follows: Figure 3 As shown, the formula for calculating the forward APC setting value of the steel drawing machine is as follows:

[0040] Forward APC setting (mm) = 2400 + 1450 - a + foremost billet width - C - 100 + 50

[0041] =3800-a+width of the first billet-C

[0042] Among them, the distance between the center line of the front C roller conveyor of the steel drawing machine when it is in the waiting position is 100mm, and the stroke value of the steel drawing machine when it is in the waiting position is 50mm.

[0043] a represents the distance of the leading edge of the foremost billet beyond γRAY;

[0044] The C value represents the distance from the front end of the steel drawing mill to the rear edge of the foremost billet, and it has the following relationship with the width of the foremost billet:

[0045] When the width of the first blank is ≥1500mm: C=300mm;

[0046] When the width of the first blank is ≤1100mm: C=150mm;

[0047] When the width of the first blank is between 1100mm and 1500mm: C = 220mm;

[0048] Calculation of the backward APC setting:

[0049] In order to accurately place the slab lifted out of the furnace by the steel extractor on the center line of the C roller table, the backward setting value of the steel extractor must be calculated.

[0050] The formula for calculating the APC setting value of the steel drawing machine retraction is as follows:

[0051] Retreat APC setting value (mm) = (foremost blank width ÷ 2) - C - 100 + 50

[0052] = (width of the first blank ÷ 2) - C - 50

[0053] In the formula: the distance between the center line of the front C-roller of the steel drawing machine and the center line of the steel drawing machine when the machine is in the waiting position is 100mm; the stroke value of the steel drawing machine when it is in the waiting position is 50mm;

[0054] C-value: The distance from the front end of the steel drawing mill to the rear edge of the foremost billet, which is related to the width of the foremost billet as follows:

[0055] When the width of the first blank is ≥1500mm: C=300mm;

[0056] When the width of the first blank is ≤1100mm: C=150mm;

[0057] When the width of the first blank is between 1100mm and 1500mm: C = 220mm.

[0058] As can be seen from the above model, the C value is only a rough estimate. In actual production, the accuracy of the C value directly affects the accuracy of the forward and backward APC stroke of the steel taking machine. Therefore, a C value of only 220mm is absolutely insufficient for slab widths within the range of 1100mm≤L≤1500mm.

[0059] (2) When the steel take-up machine stops moving forward or backward, the mechanical inertia of the equipment should be fully considered;

[0060] When a command is issued to stop the steel reclaimer, the equipment actually needs to crawl a certain distance before stopping. To achieve precise forward or backward positioning of the steel reclaimer, this crawling distance was not considered in the original program, resulting in a significant error in the steel reclaimer's positioning accuracy. Figure 4 As shown.

[0061] like Figure 5 The diagram shown is a schematic representation of a method for improving the positioning accuracy of a steel tapping machine in a heating furnace, according to an embodiment of the present invention, including:

[0062] S1: Refine the C value in the mathematical model of the hot rolling furnace steel tapping machine to obtain the C value for various widths of slabs, so as to determine the forward or backward APC stroke of the steel tapping machine;

[0063] S2: Improve the mechanical inertia of the steel take-up machine when it stops moving forward or backward using PLC, so as to position the steel take-up machine.

[0064] S3: Adjust and improve the functions of slabs of various widths so that the positioning accuracy of the steel taking machine can be directly quantified.

[0065] In this embodiment of the invention, in step S1, the refinement of the C value in the setpoint mathematical model can be achieved in the following way:

[0066] Through observation during actual production and experiments during shutdown, the forward and backward travel distances for various slab widths were measured on-site. The C-values ​​for various slab widths were calculated (e.g., by taking multiple on-site measurements and averaging them) and are shown in Table 1 below.

[0067] Table 1

[0068] slab width C value Slab width = 1550mm C = 315mm 1500mm ≤ slab width < 1550mm C = 300mm 1350mm ≤ slab width < 1500mm C = 275mm 1210mm ≤ slab width < 1350mm C = 215mm 1100mm ≤ slab width < 1210mm C = 195mm 1000mm ≤ slab width < 1100mm C = 175mm 950mm ≤ slab width < 1000mm C = 150mm Slab width < 950mm C = 140mm

[0069] In this embodiment of the invention, in step S2, a new positioning mathematical model is used in the PLC program to solve the crawling problem:

[0070] New positioning strategy for steel tapping machine in heating furnace, such as Figure 6 ,exist Figure 6 In this diagram, D represents the target position; C represents the parking point position; B represents the deceleration point position; Acc represents the deceleration of the transmission for stopping, which can be detected; Vm represents the maximum speed; Vc represents the crawling speed; Td represents the transmission delay time, a fixed value of 5 to 40 milliseconds; and Lde represents the coasting distance after issuing the stopping command from the crawling speed.

[0071] The encoder detects the actual position error Lx = Cx × Lpp; where Cx represents the pulse error detected by the encoder, Lpp represents the actual length corresponding to each pulse, and Tx represents the delay time.

[0072]

[0073] To be on the safe side, a certain crawling distance Lcd is required. Due to transmission delay, a transmission delay distance, denoted as Ldd, needs to be considered. Ldd will be different at different speeds.

[0074] therefore: Vm serves as the limiter for Vx.

[0075] The above formula is only suitable for positive error systems. In order to use the same formula for both forward and reverse positioning, the sign bit needs to be considered, as shown in the following formula:

[0076] Speed ​​given output:

[0077] in

[0078] limit When |Lx|≤Lde, the output Vx=0.

[0079] The relevant parameters are determined as follows:

[0080] Point A – the starting point for APC positioning control.

[0081] Point B – the starting point for APC positioning uniform deceleration control.

[0082] Point C – the endpoint of APC positioning uniform deceleration control.

[0083] Point D – the endpoint of APC positioning low-speed control and the starting point of crawling.

[0084] Point E – Reaching the APC positioning target location.

[0085] Based on the above strategies and methods, a mathematical model of the steel take-off machine for hot rolling furnace was established. Then, PLC control software was used to program it. The software was then debugged and the functions were improved for slabs of various widths, so that the positioning accuracy of the steel take-off machine can be directly quantified, and the purpose of automatic correction of position deviation can be achieved.

[0086] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0087] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for improving the positioning accuracy of a steel tapping machine in a heating furnace, characterized in that, include: The C value in the mathematical model of the hot rolling furnace steel tapping machine is refined to obtain the C value for various slab widths, so as to determine the forward or backward APC stroke of the steel tapping machine. The C value represents the distance from the front end of the steel tapping machine to the rear edge of the foremost slab. The mechanical inertia of the steel take-up machine is improved by using a PLC when it stops moving forward or backward, so as to position the steel take-up machine. Adjustments and functional improvements were made to slabs of various widths to enable direct quantification of the positioning accuracy of the steel take-up machine; The method of improving the mechanical inertia of the steel take-up machine when it stops moving forward or backward using a PLC to position the steel take-up machine includes: Depend on After receiving the command to stop the steel take-up machine in either forward or backward directions, the speed value of the steel take-up machine is... Vx , Lx To detect the actual position error of the encoder, Acc For the deceleration of the transmission when stopping, This represents the crawling distance. This is the transmission delay distance; limit ,exist When, output , Vc For crawling speed, Vm For maximum speed, Lde The distance traveled after a stop command is issued from the crawling speed.

2. The method according to claim 1, characterized in that, The C-value in the mathematical model of the hot rolling furnace steel tapping machine is refined to obtain C-values ​​for various slab widths, including: Through actual production processes and experiments during shutdowns, the forward and backward travel of various slab widths was measured on-site to obtain the C-value for various slab widths.

3. The method according to claim 2, characterized in that, When the width of the slab is less than 950mm, the C value is 140mm; when the width of the slab is less than or equal to 950mm, the C value is 150mm; when the width of the slab is less than or equal to 1000mm, the C value is 175mm; when the width of the slab is less than or equal to 1100mm, the C value is 195mm; when the width of the slab is less than or equal to 1210mm, the C value is 215mm; when the width of the slab is less than or equal to 1350mm, the C value is 275mm; when the width of the slab is less than or equal to 1500mm, the C value is 300mm; when the width of the slab is equal to or equal to 1550mm, the C value is 315mm.

4. The method according to claim 3, characterized in that, , Td This is the transmission delay time.

5. A device for improving the positioning accuracy of a steel tapping machine in a heating furnace, characterized in that, include: The C-value refinement module is used to refine the C-value in the mathematical model of the hot rolling furnace steel tapping machine to obtain the C-value for various slab widths, so as to determine the forward or backward APC stroke of the steel tapping machine. The C-value represents the distance from the front end of the steel tapping machine to the rear edge of the foremost slab. The PLC module is used to improve the mechanical inertia of the steel take-up machine when it moves forward or backward and stops, so as to position the steel take-up machine. The debugging module is used to debug and improve the functions of slabs of various widths, so that the positioning accuracy of the steel taking machine can be directly quantified. Specifically, the PLC module is used by... After receiving the command to stop the steel take-up machine in either forward or backward directions, the speed value of the steel take-up machine is... Vx , Lx To detect the actual position error of the encoder, Acc For the deceleration of the transmission when stopping, This represents the crawling distance. For transmission delay distance; limit ,exist When, output , Vc For crawling speed, Vm For maximum speed, Lde The distance traveled after a stop command is issued from the crawling speed.

6. The apparatus according to claim 5, characterized in that, The C-value refinement module is used to measure the forward and backward travel of various slab widths on-site through actual production processes and experiments during shutdowns, and to obtain the C-value for various slab widths.

7. The apparatus according to claim 6, characterized in that, When the width of the slab is less than 950mm, the C value is 140mm; when the width of the slab is less than or equal to 950mm, the C value is 150mm; when the width of the slab is less than or equal to 1000mm, the C value is 175mm; when the width of the slab is less than or equal to 1100mm, the C value is 195mm; when the width of the slab is less than or equal to 1210mm, the C value is 215mm; when the width of the slab is less than or equal to 1350mm, the C value is 275mm; when the width of the slab is less than or equal to 1500mm, the C value is 300mm; when the width of the slab is equal to or equal to 1550mm, the C value is 315mm.

8. The apparatus according to claim 7, characterized in that, , Td This is the transmission delay time.

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