Hydraulic control system for AGC cylinder of eighteen-roller rolling mill

Abstract

The utility model relates to a kind of AGC cylinder's hydraulic control system of eighteen-roller rolling mill, including AGC cylinder, first stop valve, first check valve, first reversing valve, second reversing valve and third reversing valve;Form a road precision thickness control loop by first reversing valve and second reversing valve, third reversing valve constitutes quick control loop, when needing to carry out quick control to AGC cylinder, using third reversing valve carries out quick control;When needing to carry out precision control, using the control loop controlled by first reversing valve and second reversing valve;Therefore, the utility model uses two-way control loop to control AGC cylinder quick action and precision action respectively, improve response efficiency, while reduce the use time of precision thickness control loop, to improve the service life and precision of precision thickness control loop.

Description

Technical Field

[0001] This utility model relates to the technical field of hydraulic control systems for rolling mills, specifically to a hydraulic control system for the AGC cylinder of an 18-roll rolling mill. Background Technology

[0002] The hydraulic AGC (Automatic Gauge Control) thickness automatic control system of the 18-roll mill mainly consists of a computer, control equipment primarily composed of detection elements, and an actuator primarily composed of a set of hydraulic cylinders. There is one hydraulic cylinder on each of the operating and transmission sides, and a position sensor at the center of each hydraulic cylinder to detect the displacement of the AGC cylinder piston. Each hydraulic cylinder also has a pressure sensor to detect the rolling pressure on both sides during operation.

[0003] Regarding the hydraulic control circuit, for each AGC cylinder, two high-frequency response servo valves control the rodless chamber of the double-acting piston cylinder, one master and one slave. The rod chamber of the cylinder is set with a constant back pressure via a three-way pressure reducing valve, with a pressure of 30 bar during rolling and switching to approximately 80 bar during rapid roll changing. During rapid pressing, both servo valves operate simultaneously, outputting a large flow rate. During rolling, the main valve operates, outputting a small flow rate to meet the requirements of precise control of the rolling process.

[0004] Existing technology uses a dual hydraulic control circuit, one master and one slave, to simultaneously control the AGC cylinder to achieve rapid pressing action. Overuse of the precision control circuit leads to a decrease in control accuracy. Utility Model Content

[0005] To address the technical problems in existing technologies, such as the use of two hydraulic control circuits (one master and one slave) to simultaneously control the AGC cylinder for rapid pressing, and the resulting reduction in control accuracy due to overuse of the precision control circuit, this invention provides a hydraulic control system for the AGC cylinder of an 18-roll mill.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A hydraulic control system for an AGC cylinder of an 18-roll mill includes an AGC cylinder, a first shut-off valve, a first check valve, a first directional valve, a second directional valve, and a third directional valve. One end of the first shut-off valve is connected to the oil supply pipe, and the other end of the first shut-off valve is connected to the pressure inlet of the first directional valve through a hydraulic pipeline. The return port of the first directional valve is connected to the inlet of the first check valve through a hydraulic pipeline. The drain port of the first check valve is used to connect to the oil tank. The two working ends of the first directional valve are respectively connected to the pressure inlet and the return port of the second directional valve. The two working ends of the second directional valve are respectively connected to the rod chamber and the rodless chamber of the AGC cylinder through hydraulic pipelines. The other end of the first shut-off valve is connected to the pressure inlet of the third directional valve via a hydraulic pipeline. The return port of the third directional valve is connected to the inlet of the first check valve via a hydraulic pipeline. The two working ends of the third directional valve are respectively connected to the rod chamber and rodless chamber of the AGC cylinder via hydraulic pipelines.

[0007] The beneficial effects of this utility model are as follows: a precision thickness control loop is formed by the first and second directional valves, and a rapid control loop is formed by the third directional valve. When rapid control of the AGC cylinder is required, the third directional valve is used for rapid control; when precision control is required, the control loop formed by the first and second directional valves is used. Therefore, this utility model uses two control loops to control the rapid and precise actions of the AGC cylinder respectively, improving response efficiency and reducing the usage time of the precision thickness control loop, thereby improving the service life and accuracy of the precision thickness control loop.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, it also includes a second shut-off valve and a second check valve, wherein the first reversing valve, the second reversing valve and the third reversing valve are all hydraulically controlled reversing valves; One end of the second shut-off valve is connected to the hydraulic control oil pipe, and the other end of the second shut-off valve is connected to the control inlet of the first directional valve, the control inlet of the second directional valve, and the control inlet of the third directional valve through hydraulic pipes. The oil inlet of the second check valve is connected to the control return port of the first directional valve, the control return port of the second directional valve, and the control return port of the third directional valve through hydraulic pipes. The oil outlet of the second check valve is used to connect to the oil tank.

[0010] The beneficial effect of adopting the above-mentioned further solution is that the shut-off and flow status of the control oil circuit can be controlled by the second shut-off valve.

[0011] Furthermore, it also includes a filter, the inlet of which is connected to the other end of the second shut-off valve via a hydraulic pipe, and the outlet of which is connected to the control inlet of the first reversing valve, the control inlet of the second reversing valve, and the control inlet of the third reversing valve via hydraulic pipes respectively.

[0012] The beneficial effect of adopting the above-mentioned further solution is that by setting up a filter to filter impurities and contaminants in the hydraulic system, the cleanliness of the hydraulic oil is ensured, thereby protecting the hydraulic components from wear and damage and extending the service life of the equipment.

[0013] Furthermore, it also includes a first relief valve, the oil inlet of which is connected to one of the working ends of the second directional valve via a hydraulic pipeline, and the oil outlet of the first relief valve is connected to the oil inlet of the first check valve via a hydraulic pipeline.

[0014] Furthermore, it also includes a second relief valve, the oil inlet of which is connected to the other working end of the second directional valve via a hydraulic pipeline, and the oil outlet of the second relief valve is connected to the oil inlet of the first check valve via a hydraulic pipeline.

[0015] The beneficial effect of adopting the above-mentioned further solution is that by connecting relief valves to the rod chamber and rodless chamber of the AGC cylinder respectively, when the system pressure exceeds the specified value, the safety valve opens, draining a portion of the hydraulic oil in the system into the tank, so that the system pressure does not exceed the allowable value, thereby ensuring that the system does not have an accident due to excessive pressure.

[0016] Furthermore, it also includes a third shut-off valve and a first accumulator, wherein the filling port of the first accumulator is connected to one end of the third shut-off valve, and the other end of the third shut-off valve is connected to the other end of the first shut-off valve.

[0017] Furthermore, it also includes a fourth shut-off valve and a second accumulator, wherein the filling port of the second accumulator is connected to one end of the fourth shut-off valve, and the other end of the fourth shut-off valve is connected to the oil inlet of the first check valve.

[0018] The beneficial effect of adopting the above-mentioned further solution is that, by setting up an energy accumulator, the energy in the system can be converted into compressed energy or potential energy and stored at appropriate times. When the system needs it, the compressed energy or potential energy can be converted into hydraulic or pneumatic energy and released to replenish the system. When the system pressure increases instantaneously, it can absorb this part of the energy to ensure that the pressure of the entire system remains normal.

[0019] Furthermore, it also includes two fifth shut-off valves, one end of which is connected to the rod chamber of the AGC cylinder, and the other end of which is connected to the rodless chamber of the AGC cylinder; the other end of one fifth shut-off valve is connected via a hydraulic pipeline to one working end of the second directional valve and one working end of the third directional valve, respectively, and the other end of the other fifth shut-off valve is connected via a hydraulic pipeline to the other working end of the second directional valve and the other working end of the third directional valve, respectively.

[0020] The beneficial effect of adopting the above-mentioned further solution is that by setting two shut-off valves, the opening and closing of the two channels of the AGC cylinder can be controlled by the two shut-off valves, thereby controlling the working enable state of the AGC cylinder.

[0021] Furthermore, it also includes two solenoid valves, with the two working ends of the third directional valve respectively connected to one end of the two solenoid valves, the other end of one solenoid valve connected to the other end of one fifth shut-off valve, and the other end of the other solenoid valve connected to the other end of the other fifth shut-off valve.

[0022] The beneficial effect of adopting the above-mentioned further scheme is that the oil inlet channel and oil outlet channel of the rapid control circuit are controlled by two solenoid valves respectively.

[0023] Furthermore, it also includes two pressure sensors, each of which is connected to the other end of one of the two fifth shut-off valves.

[0024] The advantage of adopting the above-mentioned further solution is that, by setting two pressure sensors, it is possible to monitor the hydraulic pressure of the rod chamber and the rodless chamber of the AGC cylinder. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the hydraulic system of this utility model.

[0026] The attached diagram lists the components represented by each number as follows: 1. First shut-off valve; 2. First check valve; 3. Second shut-off valve; 4. Second check valve; 5. Filter; 6. Third shut-off valve; 7. Fourth shut-off valve; 8. First accumulator; 9. Second accumulator; 10. First directional valve; 11. Second directional valve; 12. Third directional valve; 13. Solenoid valve; 14. First relief valve; 15. Second relief valve; 16. Pressure sensor; 17. Fifth shut-off valve; 18. Pressure gauge; 19. Flexible pipeline; 20. Third check valve. Detailed Implementation

[0027] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0028] like Figure 1 As shown, this embodiment provides a hydraulic control system for an AGC cylinder of an 18-roll mill, including an AGC cylinder, a first shut-off valve 1, a first check valve 2, a first directional valve 10, a second directional valve 11, and a third directional valve 12. One end of the first shut-off valve 1 is connected to the oil supply pipe, and the other end of the first shut-off valve 1 is connected to the pressure inlet of the first directional valve 10 through a hydraulic pipeline. The return port of the first directional valve 10 is connected to the inlet of the first check valve 2 through a hydraulic pipeline. The outlet of the first check valve 2 is used to connect to the oil tank. The two working ends of the first directional valve 10 are respectively connected to the pressure inlet and the return port of the second directional valve 11. The two working ends of the second directional valve 11 are respectively connected to the rod chamber and the rodless chamber of the AGC cylinder through hydraulic pipelines. The other end of the first shut-off valve 1 is connected to the pressure inlet of the third directional valve 12 via a hydraulic pipeline. The return port of the third directional valve 12 is connected to the inlet of the first check valve 2 via a hydraulic pipeline. The two working ends of the third directional valve 12 are respectively connected to the rod chamber and rodless chamber of the AGC cylinder via hydraulic pipelines. The first directional valve 10, the second directional valve 11, and the third directional valve 12 are all hydraulically controlled two-position four-way servo valves.

[0029] It also includes two fifth shut-off valves 17 and two pressure sensors 16. One end of one fifth shut-off valve 17 is connected to the rod chamber of the AGC cylinder, and one end of the other fifth shut-off valve 17 is connected to the rodless chamber of the AGC cylinder. The other end of one fifth shut-off valve 17 is connected via hydraulic pipes to one working end of the second directional valve 11 and one working end of the third directional valve 12, respectively. The other end of the other fifth shut-off valve 17 is connected via hydraulic pipes to the other working end of the second directional valve 11 and the other working end of the third directional valve 12, respectively. By setting two shut-off valves, the opening and closing of the two channels of the AGC cylinder can be controlled, thereby controlling the working enable state of the AGC cylinder.

[0030] It also includes two pressure sensors 16, each connected to the other end of one of the two fifth shut-off valves 17. By providing two pressure sensors 16, the hydraulic pressure in the rod-side and rodless-side chambers of the AGC cylinder can be monitored.

[0031] Two sets of servo valves control the system: servo valve 10 for precision control and servo valve 12 for rapid action control. Port A of the servo valve is connected to the rodless chamber of the hydraulic cylinder, and port B is connected to the rod chamber. Pressure sensors are installed at ports A and B to monitor pressure changes in the hydraulic cylinder in real time. During rolling, the servo valve's input signal is adjusted positively or negatively near zero. To avoid pressure fluctuations during cylinder reversal, which could cause fluctuations in rolling force, the servo valve uses a specially designed valve core. The ratio of the servo valve core's throttling window area to the ratio of the effective working area of ​​the rodless chamber to the effective working area of ​​the rod chamber is perfectly matched.

[0032] In this embodiment of the invention, a precision thickness control loop is formed by the first reversing valve 10 and the second reversing valve 11, and a rapid control loop is formed by the third reversing valve 12. When rapid control of the AGC cylinder is required, the third reversing valve 12 is used for rapid control; when precision control is required, the control loop formed by the first reversing valve 10 and the second reversing valve 11 is used for control. Therefore, this invention uses two control loops to control the rapid action and precision action of the AGC cylinder respectively, improving response efficiency and reducing the usage time of the precision thickness control loop, thereby improving the service life and accuracy of the precision thickness control loop.

[0033] In some embodiments, the hydraulic control system further includes a second shut-off valve 3 and a second check valve 4, wherein the first directional valve 10, the second directional valve 11 and the third directional valve 12 are all hydraulically controlled directional valves. One end of the second shut-off valve 3 is connected to the hydraulic control oil pipe, and the other end of the second shut-off valve 3 is connected to the control inlet of the first directional valve 10, the control inlet of the second directional valve 11, and the control inlet of the third directional valve 12 via hydraulic pipes. The oil inlet of the second check valve 4 is connected to the control return port of the first directional valve 10, the control return port of the second directional valve 11, and the control return port of the third directional valve 12 via hydraulic pipes. The oil outlet of the second check valve 4 is used to connect to the oil tank. The shut-off valve 3 can control the flow of the control oil circuit.

[0034] In some embodiments, a filter 5 is also included. The inlet of the filter 5 is connected to the other end of the second shut-off valve 3 via a hydraulic pipe, and the outlet of the filter 5 is connected to the control inlet of the first directional valve 10, the control inlet of the second directional valve 11, and the control inlet of the third directional valve 12 via hydraulic pipes, respectively.

[0035] By setting up filter 5 to filter impurities and contaminants in the hydraulic system, the cleanliness of the hydraulic oil is ensured, thereby protecting hydraulic components from wear and damage and extending the service life of the equipment.

[0036] In some embodiments, the system further includes a first relief valve 14 and a second relief valve 15. The inlet of the first relief valve 14 is connected to one of the working ends of the second directional valve 11 via a hydraulic pipeline, and the outlet of the first relief valve 14 is connected to the inlet of the first check valve 2 via a hydraulic pipeline.

[0037] The oil inlet of the second relief valve 15 is connected to the other working end of the second directional valve 11 through a hydraulic pipeline, and the oil outlet of the second relief valve 15 is connected to the oil inlet of the first check valve 2 through a hydraulic pipeline.

[0038] By connecting relief valves to the rod-side and rodless-side chambers of the AGC cylinder, when the system pressure exceeds the specified value, the safety valve opens, discharging a portion of the hydraulic oil into the tank, ensuring that the system pressure does not exceed the allowable value, thereby preventing accidents caused by excessive pressure.

[0039] In some embodiments, the system further includes a third shut-off valve 6 and a first accumulator 8, wherein the filling port of the first accumulator 8 is connected to one end of the third shut-off valve 6, and the other end of the third shut-off valve 6 is connected to the other end of the first shut-off valve 1.

[0040] In some embodiments, the system further includes a fourth shut-off valve 7 and a second accumulator 9, wherein the filling port of the second accumulator 9 is connected to one end of the fourth shut-off valve 7, and the other end of the fourth shut-off valve 7 is connected to the oil inlet of the first one-way valve 2.

[0041] By installing an energy accumulator, energy in the system can be converted into compressed energy or potential energy and stored at appropriate times. When the system needs it, the compressed energy or potential energy can be converted into hydraulic or pneumatic energy and released to replenish the system. When the system pressure increases instantaneously, it can absorb this energy to ensure that the pressure of the entire system remains normal.

[0042] In some embodiments, two solenoid valves 13 are also included. The two working ends of the third directional valve 12 are respectively connected to one end of the two solenoid valves 13, the other end of one solenoid valve 13 is connected to the other end of one fifth shut-off valve 17, and the other end of the other solenoid valve 13 is connected to the other end of the other fifth shut-off valve 17.

[0043] The oil inlet and outlet channels of the rapid control circuit are controlled by two solenoid valves 13 respectively.

[0044] In some embodiments, the system further includes two pressure gauges 18, two flexible pipes 19, and two third check valves 20. The inlet of one third check valve 20 is connected to the other end of one of the fifth shut-off valves 17; the outlet of the other third check valve 20 is connected to the other end of the other fifth shut-off valve 17. The two pressure gauges 18 are connected to the inlets of the two third check valves 20 via the two flexible pipes 19. Pressure oil can be supplied to the system through an external oil supply system and device via the two flexible pipes 19 to supplement the system pressure or hydraulic oil.

[0045] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic control system for an AGC cylinder of an 18-roll mill, characterized in that: It includes an AGC cylinder, a first shut-off valve (1), a first check valve (2), a first directional valve (10), a second directional valve (11), and a third directional valve (12). One end of the first shut-off valve (1) is connected to the oil supply pipe, and the other end of the first shut-off valve (1) is connected to the pressure inlet of the first directional valve (10) through a hydraulic pipeline. The return port of the first directional valve (10) is connected to the inlet of the first check valve (2) through a hydraulic pipeline. The drain port of the first check valve (2) is used to connect to the oil tank. The two working ends of the first directional valve (10) are respectively connected to the pressure inlet and the return port of the second directional valve (11). The two working ends of the second directional valve (11) are respectively connected to the rod chamber and the rodless chamber of the AGC cylinder through a hydraulic pipeline. The other end of the first shut-off valve (1) is connected to the pressure inlet of the third directional valve (12) through a hydraulic pipeline. The return port of the third directional valve (12) is connected to the inlet of the first check valve (2) through a hydraulic pipeline. The two working ends of the third directional valve (12) are respectively connected to the rod chamber and rodless chamber of the AGC cylinder through hydraulic pipelines.

2. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 1, characterized in that: It also includes a second shut-off valve (3) and a second check valve (4), wherein the first reversing valve (10), the second reversing valve (11) and the third reversing valve (12) are all hydraulically controlled reversing valves; One end of the second shut-off valve (3) is connected to the hydraulic control oil pipe, and the other end of the second shut-off valve (3) is connected to the control inlet of the first directional valve (10), the control inlet of the second directional valve (11) and the control inlet of the third directional valve (12) through hydraulic pipes. The oil inlet of the second check valve (4) is connected to the control return port of the first directional valve (10), the control return port of the second directional valve (11) and the control return port of the third directional valve (12) through hydraulic pipes. The oil outlet of the second check valve (4) is used to connect to the oil tank.

3. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 2, characterized in that: It also includes a filter (5), the inlet of which is connected to the other end of the second shut-off valve (3) via a hydraulic pipe, and the outlet of the filter (5) is connected to the control inlet of the first directional valve (10), the control inlet of the second directional valve (11), and the control inlet of the third directional valve (12) via hydraulic pipes respectively.

4. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 1, characterized in that: It also includes a first relief valve (14), the oil inlet of the first relief valve (14) is connected to one of the working ends of the second directional valve (11) through a hydraulic pipeline, and the oil outlet of the first relief valve (14) is connected to the oil inlet of the first check valve (2) through a hydraulic pipeline.

5. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 4, characterized in that: It also includes a second relief valve (15), the oil inlet of the second relief valve (15) is connected to the other working end of the second directional valve (11) through a hydraulic pipeline, and the oil outlet of the second relief valve (15) is connected to the oil inlet of the first check valve (2) through a hydraulic pipeline.

6. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 1, characterized in that: It also includes a third shut-off valve (6) and a first accumulator (8), the filling port of the first accumulator (8) is connected to one end of the third shut-off valve (6), and the other end of the third shut-off valve (6) is connected to the other end of the first shut-off valve (1).

7. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 1, characterized in that: It also includes a fourth shut-off valve (7) and a second accumulator (9), the filling port of the second accumulator (9) being connected to one end of the fourth shut-off valve (7), and the other end of the fourth shut-off valve (7) being connected to the oil inlet of the first check valve (2).

8. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 1, characterized in that: It also includes two fifth shut-off valves (17), one end of which is connected to the rod chamber of the AGC cylinder, and the other end of which is connected to the rodless chamber of the AGC cylinder; the other end of one fifth shut-off valve (17) is connected to one working end of the second directional valve (11) and one working end of the third directional valve (12) respectively through a hydraulic pipeline, and the other end of the other fifth shut-off valve (17) is connected to the other working end of the second directional valve (11) and the other working end of the third directional valve (12) respectively through a hydraulic pipeline.

9. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 8, characterized in that: It also includes two solenoid valves (13), the two working ends of the third directional valve (12) are respectively connected to one end of the two solenoid valves (13), the other end of one solenoid valve (13) is connected to the other end of one fifth shut-off valve (17), and the other end of the other solenoid valve (13) is connected to the other end of the other fifth shut-off valve (17).

10. The hydraulic control system for the AGC cylinder of the 18-roll mill according to claim 8, characterized in that: It also includes two pressure sensors (16), which are respectively connected to the other end of the two fifth shut-off valves (17).

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