Automatic control system of continuous casting billet burial pit

Abstract

The utility model relates to an automatic control system of a continuous casting billet burial pit. The automatic control system comprises a main control unit, a man-machine operation unit, a pit cover position detection unit, a redundancy anti-collision unit, an electrical control unit, a crown block position detection unit and a weighing signal detection unit, the main control unit comprises a PLC (Programmable Logic Controller) control system; the PLC control system exchanges data with the man-machine operation unit through a switch; the man-machine operation unit comprises a central control HMI picture and a switch, and communicates with the main control unit through the Ethernet. The pit cover position detection unit is used for providing pit cover position information for the main control unit, the redundancy anti-collision unit is used for safety guarantee, the electrical control unit is used for driving the pit cover, the operation efficiency of the continuous casting slab slow cooling pit is improved, and the quality control of the continuous casting slab is improved.

Description

Technical Field

[0001] The utility model relates to an automatic control system, in particular to an automatic control system suitable for a continuous casting billet slow cooling pit. Background Art

[0002] Slow cooling pits are widely used in the annealing process of high-quality continuous casting billets. The continuous casting billets are placed in the slow cooling pit and slowly cooled using the heat of the continuous casting billets themselves, which can eliminate white spots in the steel and avoid cracks caused by thermal stress and structural stress during the re-cooling process. However, conventional slow cooling pits have the following two shortcomings in automation and informatization:

[0003] 1. The traditional slow cooling pit cover control usually adopts the full-open and full-close mode. There is a large amount of heat dissipation in the process of taking the continuous casting billet, resulting in poor temperature control effect of the slow cooling pit;

[0004] 2. There is no management system for the continuous casting billets in the slow cooling pit. There are often many continuous casting billets piled up in each stack, and there is a lack of system records. In addition, the slow cooling pit often has limited space and extremely high internal temperature. It is difficult for on-site operators to view the continuous casting billet information. If there are continuous casting billets of various specifications in the pit, it is impossible to accurately find the continuous casting billets of the required specifications when taking the materials, which makes the operation inconvenient. Summary of the invention

[0005] The technical task of the utility model is to provide a low-cost slow cooling pit automatic control system to address the shortcomings of the existing slow cooling pit control system, and to complete the automatic positioning and automatic travel control of the slow cooling pit cover through PLC automatic control technology; to establish a material storage model to realize the information management of the continuous casting billets in the slow cooling pit.

[0006] The utility model solves the technical problem through a technical solution: an automatic control system for a continuous casting billet slow cooling pit, characterized in that it comprises a main control unit, a human-machine operation unit, a pit cover position detection unit, a redundant anti-collision unit, an electrical control unit, a crane position detection unit, and a weighing signal detection unit.

[0007] The main control unit includes a PLC control system; the PLC control system exchanges data with the human-machine operation unit via a switch.

[0008] The human-machine operation unit includes a central control HMI screen and a switch, and is connected to the main control unit via an optical fiber.

[0009] The pit cover position detection unit includes an online laser infrared rangefinder, which is installed at both ends of the pit cover and can convert the distance signal into a 4-20mA current signal and connect the data with the main control unit.

[0010] The redundant anti-collision unit comprises an online laser infrared rangefinder and a proximity switch, and is data-connected to the main control unit.

[0011] The electrical control unit includes a frequency converter, which is data-connected to the main control unit.

[0012] The overhead crane position detection unit comprises a trolley position detection part, a carriage position detection part and a position control cabinet.

[0013] The trolley position detection part includes a trolley terminal box, a trolley Gray bus, a trolley start box, a trolley signal generator, a trolley antenna box, and a trolley decoder. The signal generator sends a signal to the Gray bus, and the antenna box receives the signal in an electromagnetic coupling manner and sends it to the decoder. The decoder sends the signal to the address converter to parse the crane trolley position.

[0014] The trolley position detection part includes a trolley signal generator, a trolley antenna box, a trolley terminal box, a trolley Gray bus, a trolley starting box, and a trolley decoder; the signal emitted by the signal generator is transmitted to the Gray bus through the antenna box in an electromagnetic coupling manner, and is transmitted to the decoder in the starting box through the Gray bus. The decoder sends the signal to the address converter to parse the position of the overhead crane trolley.

[0015] The address converter is installed in the position control cabinet.

[0016] The weighing signal detection unit includes a weighing sensor and a weighing transmitter. The transmitter converts the weighing signal into a 4-20mA current signal, which is connected to the main control unit to detect the weight signal and then determine whether to grab and put down the continuous casting billet.

[0017] The human-machine operation unit is connected to the main control unit via optical fiber.

[0018] The position converter is connected to the main control unit via a DP cable.

[0019] The weighing transmitter is connected to the main control unit via a shielded cable.

[0020] The working process of the slow cooling pit automatic control system:

[0021] The process is divided into storing continuous casting billets and taking out continuous casting billets.

[0022] When taking out the continuous casting billet, the continuous casting billet management system determines the stack position where the continuous casting billet is located, and sends the pit cover stop position of the pit position as the target position to the pit cover motion control program. The inverter drives the displacement motor to move the pit cover to the target position. After confirming the target position, the overhead crane moves above the continuous casting billet, takes out the continuous casting billet, and closes the pit cover.

[0023] When storing continuous casting billets, the system obtains the information of the continuous casting billets, then determines the storage stack, and determines the number of continuous casting billets in the stack through the continuous casting billet management system. If the number of continuous casting billets in the stack exceeds the limit, the stack is judged to be full and the stack is searched again. If the number of continuous casting billets in the stack does not exceed the limit, they can be stored. The stop position of the pit cover of the pit is sent to the pit cover motion control program as the target position, and the displacement motor is driven by the frequency converter to move the pit cover to the target position. After confirming the target position, the overhead crane moves above the stack to store the continuous casting billets. The overhead crane moves away and the pit cover is closed.

[0024] Compared with the prior art, the utility model has the following outstanding beneficial effects:

[0025] 1. This system can realize the positioning control of the pit cover, reduce the heat dissipation in the pit, and reduce the energy consumption of temperature control.

[0026] 2. This system grids the position of the continuous casting billets. When the continuous casting billets are taken or discharged, it can automatically calculate the number of continuous casting billets, accurately locate the position of the continuous casting billets, realize the data management of the continuous casting billets in the slow cooling pit, and improve the operation efficiency.

[0027] 3. This system uses a redundant anti-collision system to avoid collision accidents caused by signal failures and ensure the safety of equipment and personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The utility model has attached Figure 2 Pages, 2 pieces in total.

[0029] Figure 1 It is a schematic diagram of embodiment 1 of the utility model.

[0030] Figure 2 It is a control flow chart of Example 1 of the utility model.

[0031] Explanation of the symbols in the figure: 1—control unit; 2—man-machine operation unit; 3—pit cover position detection unit; 4—redundant anti-collision unit; 5—electrical control unit; 6—overhead crane position detection unit; 7—weighing signal detection unit; 8—overhead crane trolley terminal box; 9—overhead crane trolley Gray busbar; 10—overhead crane trolley starting box; 11—overhead crane trolley signal generator; 12—overhead crane trolley antenna box; 13—overhead crane trolley decoder; 14—overhead crane trolley signal generator; 1 5—Crown crane trolley antenna box; 16—Crown crane trolley terminal box; 17—Crown crane trolley Gray busbar; 18—Crown crane trolley starting box; 19—Crown crane trolley decoder; 20—Address converter; 21—Position control box; 22—Switch; 23—HMI screen; 24—Proximity switch; 25—DP cable; 26—Optical fiber; 27—Shielded cable; 28—PLC control system; 29—Frequency converter; 30—Weighing sensor; 31—Weighing transmitter. DETAILED DESCRIPTION

[0032] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0033] The utility model is an automatic control system for a continuous casting slow cooling pit. Through the PLC automatic control technology, the detection of the pit cover and the overhead crane position of the slow cooling pit is realized, and the information management of the continuous casting billets in the pit is completed by establishing a storage model. Through the pit cover positioning technology, the automatic positioning and automatic travel control of the slow cooling pit cover are completed. Through the above technology, the automatic positioning and automatic travel control of the slow cooling pit cover are completed, and the number and information of the continuous casting billets are automatically managed.

[0034] like Figure 1 As shown, the system of the utility model includes a main control unit 1, a human-machine operation unit 2, a pit cover position detection unit 3, a redundant anti-collision unit 4, an electrical control unit 5, an overhead crane position detection unit 6, and a weighing signal detection unit 7.

[0035] (1) Main control unit 1

[0036] The main control unit 1 includes a PLC control system 28, which is the core of the entire system and is responsible for the operation of the control program of the entire system. The PLC control system 28 is installed in a PLC control cabinet, connected to the overhead crane signal detection unit 6, the pit cover position detection unit 3, the redundant anti-collision unit 4, the electrical control unit 5, and communicates with the human-machine operation unit 2. The PLC control cabinet is installed in the electrical room.

[0037] (2) Human-machine operation unit 2

[0038] The human-machine operation unit 2 includes an HMI screen 23 and a switch 22, which are used to provide a remote operation interface for the operator. The HMI screen is used to realize remote control of the pit cover, fault prompts, and information display of the continuous casting billets in the pit. The HMI screen is installed on the converter operating table and is connected to the main control unit 1 through an optical fiber 26.

[0039] (3) Pit cover position detection unit 3

[0040] The pit cover position detection unit 3 includes an infrared laser rangefinder, which is fixed on a bracket at one end of the pit cover. The distance between the pit cover and the infrared laser rangefinder is detected by reflecting laser from the side of the pit cover, and is connected to the main control unit 1 via a shielded cable 27.

[0041] (4) Redundant anti-collision unit 4

[0042] The redundant anti-collision unit 4 includes a proximity switch 21 and a pit cover position detection unit 3. The proximity switch 21 is installed at the extreme position of the pit cover. A T-shaped iron is installed on the pit cover. When the position of the pit cover is the extreme position of movement and the T-shaped iron is within the detection distance of the proximity switch, when the proximity switch sends a signal, the pit cover motor can be stopped urgently to prevent the pit cover from hitting the guide rail. The infrared laser rangefinder can display the distance between the pit cover and the extreme position. When the distance is less than the set value, the pit cover motor can also be stopped urgently to prevent the pit cover from hitting the guide rail. The two systems are backup for each other. When one system fails, the other system can also ensure the safety of the pit cover equipment normally.

[0043] (5) Electrical control unit 5

[0044] The electrical control unit 5 includes a frequency converter 29, through which the start, stop, direction and speed control of the motor of the pit cover are realized. The frequency converter 29 is installed in an electrical cabinet, and the electrical cabinet is installed in an electrical room.

[0045] (6) Overhead Crane Signal Detection Unit 6

[0046] The overhead crane position detection unit comprises a trolley position detection part, a carriage position detection part and a position control cabinet.

[0047] The trolley position detection part includes a trolley terminal box 8, a trolley Gray bus 9, a trolley starting box 10, a trolley signal generator 11, a trolley antenna box 12, and a trolley decoder 13. The trolley Gray bus 9 is laid along the trolley track, and the trolley terminal box 8 and the trolley starting box 10 are installed at both ends of the trolley Gray bus 9 and connected to the Gray bus. The trolley signal generator 11 is installed in the starting box 10, and the antenna box 12 is installed on the overhead crane trolley and moves with the trolley. The signal generator 11 sends a signal to the Gray bus, and the antenna box 12 receives the signal in an electromagnetic coupling manner and sends it to the decoder 13. The decoder 13 sends the signal to the address converter 20 to parse the position of the overhead crane trolley.

[0048] The trolley position detection part includes a trolley signal generator 14, a trolley antenna box 15, a trolley terminal box 16, a trolley Gray bus 17, a trolley starting box 18, and a trolley decoder 19; the trolley Gray bus 17 is laid along the trolley track, and the trolley terminal box 16 and the trolley starting box 18 are installed at both ends of the Gray bus to connect the Gray bus. The trolley antenna box 15 is installed on the trolley and moves with the trolley. The trolley signal generator 14 is installed in the antenna box. The signal generator 14 sends a signal, which is sent to the Gray bus 17 by electromagnetic coupling through the antenna box 15. The Gray bus 17 transmits the signal to the decoder 19 in the starting box 18. The decoder 19 sends the signal to the address converter 20 to parse the position of the overhead crane trolley.

[0049] The address converter 20 is installed in a position control cabinet 21 , and the position control cabinet 21 is connected to the main control unit 1 via a DP cable 25 .

[0050] (7) Weighing signal detection unit 7

[0051] The weighing signal detection unit 7 includes a weighing sensor 30 and a weighing transmitter 31. The weighing transmitter 31 converts the weighing signal into a 4-20 mA current signal and connects to the main control unit 1 to detect the weight signal. The weighing transmitter 31 is connected to the main control system using a shielded cable 27.

[0052] The control contents of this utility model are mainly:

[0053] 1. Pit cover position detection

[0054] The horizontal position of the pit cover is determined by the detection signal of the pit cover position detection unit. The pit cover position detection unit uses a laser infrared rangefinder, which has the characteristics of safety, simple installation, high precision, etc. The detection accuracy is at the millimeter level.

[0055] 2. Pit cover travel control

[0056] The pit cover travel control mainly includes the automatic control of the pit cover travel direction and the stop control.

[0057] According to the position of the continuous casting billet stack, the pit cover stop position of different stacks is defined, which is recorded as a1, a2...a n , according to the current position of the pit cover, recorded as b, the storage position is determined according to the offline information, and the target position of the pit cover is recorded as a=a n , compare the data of a and b. When a>b, the frequency converter is used to control the pit cover to move away from the laser rangefinder. When a<b, the pit cover is controlled to move toward the laser rangefinder.

[0058] Stop control, according to the kinetic energy formula, the ideal stop distance L = 0.5Vt can be obtained, where V is the speed at stop and t is the time used for stop. Since the inverter reacts quickly, it can be regarded as t = V / a, where a is the acceleration, which is related to friction. Through friction and motion formula, t = V / (μg) can be obtained, and then L = O,5V2 / (μg), where μ is the friction coefficient and g is the acceleration of gravity. Due to other influences, the calculation formula can be simplified to L = 0.5V2 / (μg) + α, where α is a fixed constant. By recording the stop distance, the approximate values ​​of μg and α can be calculated, so the braking distance L is obtained. This calculation method can meet the braking requirements at different speeds. Decelerate and stop at a distance L from the target position, with high control accuracy, which can reach 5mm.

[0059] 3. Acquisition of continuous casting billet information

[0060] The continuous casting billet information is obtained by exchanging information with the MES system. The communication method adopts TCP communication to obtain the material code of the continuous casting billet.

[0061] 4. Determine the storage location

[0062] According to the horizontal distance between the overhead crane position detection unit and the pit cover position detection unit, the position of the overhead crane trolley and the trolley corresponding to each stack position can be determined.

[0063] According to the divided storage areas, the location where the continuous casting billets need to be stored can be determined by comparing the continuous casting billet information and the number of continuous casting billets that have been stored.

[0064] 5. Continuous casting billet information management

[0065] Continuous casting billet information management includes continuous casting billet location management, quantity statistics, and information management.

[0066] The position management is to divide the slow cooling pit into several positions according to the horizontal position and the vertical position. Each continuous casting billet corresponds to one position. The horizontal position is divided according to the stack number, recorded as 1, 2, 3...n, and the vertical position is divided according to the number of continuous casting billets that can be stacked, which is n-1, n-2...nm in the nth stack.

[0067] The quantity statistics are obtained by coordinating the lifting direction and the moving direction with the overhead crane weighing sensor to determine the stacking quantity of the continuous casting billets. When the weighing sensor detects that there is a continuous casting billet below, if it moves upward, the continuous casting billet will be separated from the stack; if it moves downward and the continuous casting billet is finally separated from the overhead crane clamp, it is judged that the continuous casting billet is placed on the stack.

[0068] The continuous casting billet information management is realized through a PLC program. A DB block is established in the PLC program to store the continuous casting billet information of the corresponding stack position. The corresponding address is located by programming using a pointer to realize rapid reading and storage of the continuous casting billet information.

[0069] 6. Limit position judgment

[0070] The limit position refers to the edge position of the pit cover. If it exceeds this position, it may hit the edge of the track, causing a safety hazard. There are two methods for judgment. Method 1: Use the signal of the proximity switch installed at the edge position to judge. When the proximity switch sends a limit position signal, it is determined that the pit cover has reached the limit position. Method 2: Judge by the position of the pit cover, set the limit positions of the two ends of the pit cover in advance as a and b, where a is the far limit position and b is the near limit position. When the pit cover detection position is greater than or equal to a or less than or equal to b, it is judged that the pit cover has reached the limit position.

[0071] The main control functions of the utility model system include: automatic control of the pit cover, automatic management of the continuous casting billet information in the pit, and safety management function.

[0072] 1. Automatic control of pit cover

[0073] The storage position is determined according to the information of the continuous casting billet to be stored or retrieved, and the pit cover automatically moves to the corresponding position. The pit cover and the overhead crane are controlled in linkage through the pit cover position detection and the overhead crane position detection.

[0074] 2. Automatic management of continuous casting billet information in the pit

[0075] According to the deposit or withdrawal operation of the continuous casting billet, the continuous casting billet information at the corresponding position is automatically processed, and the number and number of the continuous casting billets stored in all stacks are displayed on the HMI screen.

[0076] 3. Security Control

[0077] Safety control is the key function of this system control and is integrated into every function: including: one-touch emergency stop, interlocking of overhead crane and pit cover position, communication fault alarm, control authority control, inverter fault prompt, pit cover anti-collision function, etc., to ensure the safety of personnel and equipment through safety control.

[0078] The above-mentioned ideal embodiments of the utility model are inspirations. Through the above-mentioned description, relevant staff can make various changes and modifications without deviating from the technical concept of the utility model. The technical scope of the utility model is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An automatic control system for a continuous casting billet slow cooling pit, characterized in that It includes main control unit, human-machine operation unit, pit cover position detection unit, redundant anti-collision unit, electrical control unit, overhead crane position detection unit, and weighing signal detection unit; The main control unit includes a PLC control system; the PLC control system exchanges data with the human-machine operation unit through a switch; The human-machine operation unit includes a central control HMI screen and a switch, and communicates with the main control unit via Ethernet; The pit cover position detection unit includes an online laser infrared rangefinder, which is installed at both ends of the pit cover and can convert the distance signal into a 4-20mA current signal and connect the data with the main control unit; The redundant anti-collision unit includes an online laser infrared rangefinder and a proximity switch, which are data-connected to the main control unit; The electrical control unit includes a frequency converter, which is data-connected to the main control unit; The overhead crane position detection unit comprises a trolley position detection part, a trolley position detection part and a position control cabinet; The trolley position detection part includes a trolley terminal box, a trolley Gray bus, a trolley start box, a trolley signal generator, a trolley antenna box, and a trolley decoder; the signal generator sends a signal to the Gray bus, the antenna box receives the signal in an electromagnetic coupling manner and sends it to the decoder, and the decoder sends the signal to the address converter to parse the crane trolley position; The trolley position detection part includes a trolley signal generator, a trolley antenna box, a trolley terminal box, a trolley Gray bus, a trolley start box, and a trolley decoder; the signal emitted by the signal generator is transmitted to the Gray bus by electromagnetic coupling through the antenna box, and then transmitted to the decoder in the start box through the Gray bus. The decoder sends the signal to the address converter to parse the position of the overhead crane trolley; The address converter is installed in the position control cabinet; The weighing signal detection unit includes a weighing sensor and a weighing transmitter. The transmitter converts the weighing signal into a 4-20mA current signal, which is connected to the main control unit to detect the weight signal and then determine whether to grab and put down the continuous casting billet.

2. The automatic control system of the continuous casting slow cooling pit according to claim 1, characterized in that: The human-machine operation unit is connected to the main control unit via optical fiber.

3. The automatic control system of the continuous casting slow cooling pit according to claim 1, characterized in that: The position converter is connected to the PLC control system via a DP cable.

4. The automatic control system of the continuous casting slow cooling pit according to claim 1, characterized in that: The weighing transmitter is connected to the main control unit via a shielded cable.

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