Pinch roll gap cascade control system and method with automatic calibration function

Abstract

The invention discloses a pinch roll gap cascade control system with an automatic calibration function. The pinch roll gap cascade control system comprises a hydraulic module, a detection module and an upper computer, the hydraulic modules are arranged on the two sides of the pinch roll device. The detection module is arranged on the hydraulic module; the upper computer is connected with the hydraulic module and the detection module. The invention further discloses a pinch roll gap cascade control method with the automatic calibration function. The invention provides a control system which is good in pinch roll gap adjusting effect and considers automatic calibration in the high-precision steel plate production process.

Description

Technical Field

[0001] This invention relates to automatic calibration and automatic stroke control technology for position adjustment devices in steel plate cooling systems, and more specifically, to a cascade control system and method for pinch roll gaps with automatic calibration function. Background Technology

[0002] Rapid cooling devices are used to accelerate the cooling of steel plates and directly quench them, making them a crucial part of the steel plate production process. The rapid cooling device contains multiple sets of pinch rollers, with upper and lower manifolds equipped with nozzles installed on both sides of the pinch rollers. The upper manifold is adjusted vertically by adjusting the roller gap. Simultaneously, after the steel plate enters the cooling zone, a certain clamping force is applied to the steel plate by adjusting the pressure of the pinch rollers, limiting deformation that occurs during cooling and thus ensuring a good plate shape.

[0003] In the pinch roll control system of the rapid cooling device, each individual pinch roll has an adjusting cylinder at both ends, and each cylinder is equipped with pressure and displacement sensors. Currently, the mainstream control strategy for the pinch roll gap in metallurgical production is position control. However, pure position control, considering impact prevention, often cannot descend to a position close to the steel plate. This causes water to flow backward during the cooling process of the steel plate being threaded through the roll, and the device cannot provide corresponding protection when the positions of the cylinders on both sides tilt or when the steel plate wobbles or wedges and collides with the pinch roll. Furthermore, current pinch roll calibration methods rely on manual calibration using suspended calibration plates, which is prone to errors and requires considerable manpower and time. Both of these problems affect the final cooling effect, resulting in poor uniformity and consistency of the steel plate. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a cascade control system and method for pinch roll gap with automatic calibration function, providing a control system with good pinch roll gap adjustment effect and automatic calibration consideration in the high-precision steel plate production process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides a cascade control system for pinch roll gaps with automatic calibration function, including a hydraulic module, a detection module and a host computer;

[0007] The hydraulic modules are located on both sides of the pinch roller device;

[0008] The detection module is mounted on the hydraulic module;

[0009] The host computer is connected to the hydraulic module and the detection module respectively.

[0010] Preferably, the hydraulic module includes a hydraulic cylinder and a hydraulic valve platform;

[0011] The hydraulic valve platform integrates a servo valve and a check valve.

[0012] The hydraulic cylinder has two sets, located on the working side and the transmission side of the pinch roller device, respectively.

[0013] The hydraulic cylinder is connected to the servo valve and the check valve in sequence via hydraulic pipelines.

[0014] Preferably, the detection module includes a rodless cavity-side pressure sensor, a rod-side cavity-side pressure sensor, and a displacement sensor;

[0015] The rodless cavity side pressure sensor is installed on the rodless cavity side hydraulic pipeline of the hydraulic cylinder;

[0016] The rod-side pressure sensor is located on the hydraulic line on the piston rod side of the hydraulic cylinder, and the two sets of hydraulic cylinders share one rod-side pressure sensor.

[0017] The displacement sensor is located inside the hydraulic cylinder.

[0018] Preferably, the pinch roll gap cascade control system further includes a relay control unit, a display unit, and a pinch roll control unit;

[0019] The relay control unit is connected to the servo valve, the check valve, and the detection module;

[0020] The display unit is used to display the pinch roll gap value of the pinch roll device and the pressure value of the detection module;

[0021] The pinch roll control unit is used to control the pinch roll device.

[0022] Preferably, the host computer is also connected to the relay control unit, the display unit, and the pinch roller control unit.

[0023] Preferably, the pinch roll gap cascade control system further includes a control board for controlling the operation of the hardware.

[0024] Preferably, the pinch roll control unit includes a synchronization controller, a position controller, a pressure controller, and a comparator;

[0025] The input side of the synchronization controller is connected to the displacement sensor, and the output side is connected to the input side of the comparator;

[0026] The input side of the position controller is connected to the displacement sensor, and the output side is connected to the input side of the comparator;

[0027] The output side of the comparator is connected to the input side of the pressure controller, and the output side of the pressure controller is connected to the control valve of the hydraulic valve platform.

[0028] The second aspect of this invention provides a cascade control method for the gap of a pinch roll with automatic calibration function, wherein the following steps are performed using the cascade control system for the gap of a pinch roll with automatic calibration function provided in the first aspect of this invention:

[0029] S1, Automatic calibration of the pinch rollers;

[0030] S2, Set the preset position value of the pinch roller;

[0031] S3, Position Control;

[0032] S4, Synchronization Control;

[0033] S5, pressure control.

[0034] Preferably, step S1 specifically includes the following steps:

[0035] S1.1 Log in to the host computer and turn on the power to each device;

[0036] S1.2, raise the two sides of the pinch roller device to the set safe height and keep them horizontal, while starting to rotate the pinch rollers.

[0037] S1.3, the upper pinch roller starts to descend while rotating, and descends to the set height. At this time, the overall pressure output of the hydraulic cylinders on both sides is calibrated to zero.

[0038] S1.4, the upper pinch roller continues to descend. When the upper pinch roller comes into contact with the lower pinch roller, the hydraulic cylinder is adjusted so that the pressure of the hydraulic cylinders on both sides is equal. At this time, the position output of both sides of the pinch roller is calibrated to zero.

[0039] S1.5 After automatic calibration is completed, raise the upper pinch roller to a safe height.

[0040] Preferably, step S3 specifically includes:

[0041] The actual value of the pinch roll gap measured by the displacement sensor is compared with the set value. The deviation between the two is used as the input of the position controller. Then, the input signal is processed and transformed by the position controller to obtain an output signal, which is used as the input signal of the pressure controller.

[0042] Preferably, step S4 specifically includes:

[0043] The actual value of the displacement sensor on the working side of the pinch roller device is compared with the actual value of the displacement sensor on the transmission side of the pinch roller device. The deviation between the two is used as the input of the synchronization controller. The input signal is then processed and transformed by the synchronization controller to obtain two output signals, which are fed back to the hydraulic systems on both sides respectively.

[0044] When the deviation between the two exceeds the set maximum allowable deviation, the hydraulic systems on both sides will automatically level themselves.

[0045] Preferably, step S5 specifically includes:

[0046] The actual pressure value of the hydraulic cylinder as a whole is calculated by using the feedback values ​​of the rodless chamber side pressure sensor, the rod side pressure sensor, and the piston rod area of ​​the hydraulic cylinder. The difference between the output of steps S2 and S3 and the actual pressure is used as the input of the pressure controller. The input signal is then processed and transformed by the pressure controller to obtain an output signal. This output signal is used as the set value of the corresponding servo valve on the hydraulic valve platform to adjust the opening degree.

[0047] The pinch roll gap cascade control system and method with automatic calibration function provided by this invention have the following beneficial effects:

[0048] 1) Fast response time, short calibration time, high control accuracy, equipment protection, and remote monitoring;

[0049] 2) A composite control system combining position control, pressure control, and synchronization control is adopted for the pinch rolls. When the steel plate collides with the pinch rolls due to wavering or wedge-shaped impact, the roll gap can be automatically adjusted based on the actual force, effectively protecting the equipment.

[0050] 3) The pressure control adopted can effectively adhere to the steel plate, thereby ensuring that the cooling water only stays in the corresponding area, ensuring the cooling effect, and improving the uniformity and reliability of cooling.

[0051] 4) The automatic calibration method avoids the need for manual transport of calibration plates and on-site surveys, thus improving calibration efficiency and accuracy;

[0052] 5) The automatic control of the lifting and lowering of the pinch roll is achieved by adopting a cascade control system, which ensures the stability of the pinch roll gap and is conducive to achieving high-precision cooling. At the same time, all relevant data can be displayed in real time through the host computer, which is conducive to remote monitoring. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structural framework of an embodiment of the pinch roll gap cascade control system of the present invention;

[0054] Figure 2This is a schematic diagram of the automatic calibration process in an embodiment of the pinch roll gap cascade control method of the present invention;

[0055] Figure 3 This is a schematic diagram of the automatic control of an embodiment of the pinch roll gap cascade control system of the present invention. Detailed Implementation

[0056] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0057] Combination Figure 1 As shown, the pinch roll gap cascade control system with automatic calibration function provided by the present invention includes a hydraulic module, a detection module and a host computer.

[0058] The hydraulic module is installed on both sides of the pinch roller device, namely the working side and the transmission side.

[0059] The detection module is installed on the hydraulic module.

[0060] The host computer is connected to the hydraulic module and the detection module respectively.

[0061] The hydraulic module includes a hydraulic cylinder 1 and a hydraulic valve platform 2.

[0062] The hydraulic valve console 2 integrates a servo valve 3 and a check valve 4.

[0063] Two hydraulic cylinders 1 are located on the working side and the transmission side of the pinch roller device, respectively. The working side and transmission side of the pinch roller device are connected to the piston rod 9 of the hydraulic cylinder 1. Hydraulic oil drives the piston rod to move, thereby adjusting the vertical stroke of the pinch roller. The transmission side of the pinch roller device is connected to a motor via a shaft; the rotation of the motor drives the pinch roller device to rotate synchronously. The positions of the hydraulic cylinders 1 on both sides of the pinch roller device should be consistent; otherwise, if the two ends of the pinch roller device are at different heights, tilting will occur.

[0064] Hydraulic cylinder 1 is connected to servo valve 4 and check valve 3 in sequence via hydraulic pipeline 5.

[0065] Servo valve 4 and check valve 3 are controlled by a relay switch. Check valve 3 is a solenoid valve, and both servo valve 4 are connected to the control board.

[0066] The detection module includes a rodless cavity side pressure sensor 6, a rod cavity side pressure sensor 7, and a displacement sensor 8.

[0067] The piston rod 9 inside the hydraulic cylinder 1 divides the interior of the hydraulic cylinder 1 into two parts: a rod chamber and a rodless chamber.

[0068] The rodless cavity side pressure sensor 6 is installed on the rodless cavity side hydraulic line of the hydraulic cylinder 1.

[0069] The rod-side pressure sensor 7 is installed on the hydraulic line on the piston rod side of the hydraulic cylinder 1, and the two sets of hydraulic cylinders 1 share one rod-side pressure sensor 7.

[0070] The displacement sensor 8 is installed inside the hydraulic cylinder 1.

[0071] The pinch roll gap cascade control system of the present invention also includes a relay control unit, a display unit, and a pinch roll control unit.

[0072] The relay control unit is connected to servo valve 4, check valve 3, and detection module.

[0073] The display unit is used to display the pinch roll gap value of the pinch roll device and the pressure value of the detection module.

[0074] The pinch roll control unit is used to automatically control the pinch roll device.

[0075] The pinch roll gap cascade control system also includes a host computer connected to the relay control unit, display unit, and pinch roll control unit.

[0076] The pinch roll gap cascade control system also includes a control board for controlling the hardware operation and realizing the corresponding hardware functions. The control board, control valves, controllers, pressure sensors, displacement sensors, and hydraulic cylinders constitute a closed-loop control system for realizing the automatic control of the pinch roll device.

[0077] Combination Figure 3 As shown, the pinch roll control unit includes a synchronization controller 10, a position controller 11, a pressure controller 12, and a comparator 13.

[0078] The input side of the synchronous controller 10 is connected to the displacement sensor 8, and the output side is connected to the input side of the comparator 13.

[0079] The input side of the position controller 11 is connected to the displacement sensor 8, and the output side is connected to the input side of the comparator 13.

[0080] The output side of comparator 13 is connected to the input side of pressure controller 12, and the output side of pressure controller 12 is connected to the control valve of hydraulic valve platform 2.

[0081] Combination Figure 2 and Figure 3 As shown, the present invention also provides a cascade control method for the gap of a pinch roll with automatic calibration function. The following steps are performed using the cascade control system for the gap of a pinch roll with automatic calibration function of the present invention:

[0082] S1, Automatic calibration of the pinch rollers, specifically includes the following steps:

[0083] S1.1 Log in to the host computer and turn on the power to all components, including displacement sensor 8, pressure sensor, servo valve 3, check valve 4, and pinch roller drive motor.

[0084] S1.2, raise the two sides of the pinch roller device to a certain safe height, keep the two sides roughly horizontal, and at the same time set the pinch roller motor to a certain speed to make the pinch roller start to rotate.

[0085] S1.3, while the upper pinch roller is rotating, it begins to descend. When it descends to a lower height and the upper pinch roller has not yet contacted the lower pinch roller, the overall pressure output of the hydraulic cylinders 1 on both sides is calibrated to zero.

[0086] S1.4, the upper pinch roller continues to descend. When the upper pinch roller is close to the lower pinch roller, the hydraulic cylinder 1 is finely adjusted to make the pressure of the hydraulic cylinders 1 on both sides equal. At this time, the position output on both sides of the pinch roller is calibrated to zero.

[0087] S1.5 After automatic calibration is completed, the upper pinch roller is raised to a certain safe height;

[0088] S2, Set the preset position value of the pinch roller;

[0089] S3, position control, compares the actual value of the pinch roll gap measured by the displacement sensor 8 inside the hydraulic cylinder 1 with the set value, and uses the deviation between the two as the input of the position controller 11. Then, the input signal is processed and transformed by the position controller 11 to obtain an output signal, which is used as the input signal of the subsequent pressure controller 12.

[0090] S4, Synchronous control, the actual value of the displacement sensor 8 inside the working side hydraulic cylinder 1 of the pinch roller device is compared with the actual value of the displacement sensor 8 inside the transmission side hydraulic cylinder 1 of the pinch roller device. The deviation between the two is used as the input of the synchronous controller 10. Then the input signal is processed and transformed by the synchronous controller 10 to obtain two output signals, which are fed back to the hydraulic systems on both sides respectively.

[0091] When the deviation between the two exceeds the set maximum allowable deviation, the hydraulic systems on both sides will automatically level themselves and adjust the set position of the entire system to the average value of the current positions of the hydraulic cylinders 1 on both sides, so as to avoid damage to the hydraulic cylinders 1 on both sides and related valves and corresponding devices due to excessive deviation.

[0092] S5, Pressure Control: The actual pressure value of the hydraulic cylinder 1 is calculated based on the feedback values ​​from the rodless chamber side pressure sensor 6, the rod chamber side pressure sensor 7, and the area of ​​the piston rod 9 of the hydraulic cylinder 1. The difference between the output of steps S2 and S3 and the actual pressure is used as the input of the pressure controller 12. The input signal is then processed and transformed by the pressure controller 12 to obtain an output signal. This output signal is used as the set value of the corresponding servo valve on the hydraulic valve platform 2 to adjust the opening degree and control the lifting and lowering action of the clamping machine, thereby achieving the corresponding control objective.

[0093] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A cascade control system for pinch roll gaps with automatic calibration function, characterized in that: Includes a hydraulic module, a detection module, and a host computer; The hydraulic modules are located on both sides of the pinch roller device; The detection module is mounted on the hydraulic module; The host computer is connected to the hydraulic module and the detection module respectively.

2. The pinch roll gap cascade control system with automatic calibration function according to claim 1, characterized in that: The hydraulic module includes a hydraulic cylinder and a hydraulic valve platform; The hydraulic valve platform integrates a servo valve and a check valve. The hydraulic cylinder has two sets, located on the working side and the transmission side of the pinch roller device, respectively. The hydraulic cylinder is connected to the servo valve and the check valve in sequence via hydraulic pipelines.

3. The pinch roll gap cascade control system with automatic calibration function according to claim 2, characterized in that: The detection module includes a rodless cavity side pressure sensor, a rod cavity side pressure sensor, and a displacement sensor. The rodless cavity side pressure sensor is installed on the rodless cavity side hydraulic pipeline of the hydraulic cylinder; The rod-side pressure sensor is located on the hydraulic line on the piston rod side of the hydraulic cylinder, and the two sets of hydraulic cylinders share one rod-side pressure sensor. The displacement sensor is located inside the hydraulic cylinder.

4. The pinch roll gap cascade control system with automatic calibration function according to claim 3, characterized in that: The pinch roll gap cascade control system also includes a relay control unit, a display unit, and a pinch roll control unit; The relay control unit is connected to the servo valve, the check valve, and the detection module; The display unit is used to display the pinch roll gap value of the pinch roll device and the pressure value of the detection module; The pinch roll control unit is used to control the pinch roll device.

5. The pinch roll gap cascade control system with automatic calibration function according to claim 4, characterized in that: The host computer is also connected to the relay control unit, the display unit, and the pinch roller control unit.

6. The pinch roll gap cascade control system with automatic calibration function according to claim 5, characterized in that: The pinch roll gap cascade control system also includes a control board for controlling the operation of the hardware.

7. The pinch roll gap cascade control system with automatic calibration function according to claim 5, characterized in that: The pinch roll control unit includes a synchronization controller, a position controller, a pressure controller, and a comparator; The input side of the synchronization controller is connected to the displacement sensor, and the output side is connected to the input side of the comparator; The input side of the position controller is connected to the displacement sensor, and the output side is connected to the input side of the comparator; The output side of the comparator is connected to the input side of the pressure controller, and the output side of the pressure controller is connected to the control valve of the hydraulic valve platform.

8. A method for cascade control of the gap between pinch rolls with automatic calibration function, characterized in that, The following steps are performed using the pinch roll gap cascade control system with automatic calibration function as described in any one of claims 1-7: S1, Automatic calibration of the pinch rollers; S2, Set the preset position value of the pinch roller; S3, Position Control; S4, Synchronization Control; S5, pressure control.

9. The method for cascade control of pinch roll gap with automatic calibration function according to claim 8, characterized in that, Step S1 specifically includes the following steps: S1.1 Log in to the host computer and turn on the power to each device; S1.2, raise the two sides of the pinch roller device to the set safe height and keep them horizontal, while starting to rotate the pinch rollers. S1.3, the upper pinch roller starts to descend while rotating, and descends to the set height. At this time, the overall pressure output of the hydraulic cylinders on both sides is calibrated to zero. S1.4, the upper pinch roller continues to descend. When the upper pinch roller comes into contact with the lower pinch roller, the hydraulic cylinder is adjusted so that the pressure of the hydraulic cylinders on both sides is equal. At this time, the position output of both sides of the pinch roller is calibrated to zero. S1.5 After automatic calibration is completed, raise the upper pinch roller to a safe height.

10. The method for cascade control of pinch roll gap with automatic calibration function according to claim 8, characterized in that, Step S3 specifically includes: The actual value of the pinch roll gap measured by the displacement sensor is compared with the set value. The deviation between the two is used as the input of the position controller. Then, the input signal is processed and transformed by the position controller to obtain an output signal, which is used as the input signal of the pressure controller.

11. The method for cascade control of pinch roll gap with automatic calibration function according to claim 10, characterized in that, Step S4 specifically includes: The actual value of the displacement sensor on the working side of the pinch roller device is compared with the actual value of the displacement sensor on the transmission side of the pinch roller device. The deviation between the two is used as the input of the synchronization controller. The input signal is then processed and transformed by the synchronization controller to obtain two output signals, which are fed back to the hydraulic systems on both sides respectively. When the deviation between the two exceeds the set maximum allowable deviation, the hydraulic systems on both sides will automatically level themselves.

12. The method for cascade control of the gap between pinch rolls with automatic calibration function according to claim 11, characterized in that, Step S5 specifically includes: The actual pressure value of the hydraulic cylinder as a whole is calculated by using the feedback values ​​of the rodless chamber side pressure sensor, the rod side pressure sensor, and the piston rod area of ​​the hydraulic cylinder. The difference between the output of steps S2 and S3 and the actual pressure is used as the input of the pressure controller. The input signal is then processed and transformed by the pressure controller to obtain an output signal. This output signal is used as the set value of the corresponding servo valve on the hydraulic valve platform to adjust the opening degree.

Images