Method for switching modes of HGC oil cylinder position sensor in continuous rolling process

Abstract

The invention discloses a method for automatically switching HGC oil cylinder position sensors in a continuous rolling process, which comprises the following steps: in a steel rolling process, when an HGC oil cylinder servo control system is turned into an OFF mode and the feedback position of an HGC oil cylinder on one side is abnormal, judging that the corresponding position sensor is abnormal, and alarming by the system to remind an operator; after an HGC oil cylinder position sensor gives an alarm, a normal sensor is automatically switched to be used on one side; and steel feeding is allowed only after the HGC servo control ON is used again. By the adoption of the method, the actual state of the HGC oil cylinder position sensor and position control of the HGC oil cylinder servo control system are effectively combined, automatic alarming and mode switching preparation can be achieved after one position sensor of the HGC oil cylinder is damaged, an operator only needs to confirm and reuse the HGC oil cylinder servo control system to be in the ON mode, steel rolling can be continued, and the production efficiency is improved. And the operation steps of operators are effectively reduced, and the non-planned shutdown time of the rolling line is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of hot rolling roughing mill control, and in particular to a method for switching modes of an HGC oil cylinder position sensor during continuous rolling. Background Art

[0002] The roughing mill is equipped with two HGC cylinders, which are installed on the operating side and the transmission side of the mill respectively. The HGC cylinders have two main functions: roll gap adjustment and hydraulic leveling. When adjusting the roll gap, the two HGC cylinders move in the same direction, and the two cylinders rise or fall at the same time to adjust the roll gap to open or close. When hydraulic leveling is performed, the HGC cylinders on both sides move in opposite directions, one side rises and the other side falls, to adjust the horizontality of the roll.

[0003] The diameter of the HGC cylinder is 965mm, which is relatively large. In order to detect whether the HGC cylinder is in a balanced state during operation and avoid damage to the cylinder due to the influence of the eccentric load, two position sensors are installed on each cylinder to detect the position of the cylinder. The two position sensors are installed on the rolling mill entrance and exit directions of the cylinder respectively. Under normal circumstances, the bilateral use mode is adopted, that is, the cylinder position sensors at two positions are used at the same time to detect the actual position of the cylinder. The average value of the entrance position sensor and the exit position sensor is the actual position of the cylinder. That is, the actual position of the cylinder H= (H 入口 +H 出口 ) / 2. (Where: H 入口 —Inlet position sensor detection value; H 出口 —Exit position sensor detection value) When one of the sensors at the entrance or exit is damaged, it can be temporarily switched to single-side mode for operation, that is, switched to a normal sensor for single-side use. However, when one of the position sensors is damaged, the HGC servo control system mode becomes OFF to disconnect the servo system output, so that the HGC cylinder is locked in the position when the sensor is abnormal and cannot continue to move. And after the servo control system is OFF, if the deviation between the set position and the feedback position of the HGC cylinder does not exceed ±0.5mm, steel rolling can continue. In this process, although the set position and feedback position of the HGC cylinder are within the allowable deviation range, steel rolling is allowed to continue, but the HGC servo control system OFF causes the hydraulic leveling to be unusable. If there is sickle bending during the steel rolling process, hydraulic leveling cannot be performed, which may cause serious consequences such as severe sickle bending and the slab hitting the guide plate.

[0004] After the HGC cylinder position sensor was damaged and the servo control system was turned OFF, it was not discovered until the HGC cylinder set position changed significantly and the set position and actual position deviated by more than ±0.5mm, causing the rolling mill to not feed steel. Then, after inspection, judgment and confirmation by the operator, the operator needs to manually switch to normal single-side use of the sensor, re-activate the servo control system ON, and manually reset the HGC cylinder position by APC before steel rolling can be resumed. In this way, the entire inspection, confirmation and operation process takes a long time. If the operation is improper during the process, it will take longer and the slab temperature will drop more, resulting in the slab needing to be returned to the furnace or pushed into long strips. Summary of the invention

[0005] The purpose of the present invention is to provide a method for switching the mode of an HGC cylinder position sensor during continuous rolling, which effectively combines the actual state of the HGC cylinder position sensor and the position control of the HGC cylinder servo control system to realize automatic alarm and remind the operator after an abnormality occurs in the HGC cylinder position sensor, thereby achieving the purpose of automatic switching of the HGC cylinder position sensor, effectively reducing the inspection and judgment process of the operator, and reducing the unplanned downtime after the HGC cylinder position sensor fails.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a method for automatically switching the HGC cylinder position sensor during continuous rolling, characterized in that it comprises the following steps: Step 1: During the steel rolling process, when the HGC cylinder servo control system changes to the OFF mode and the HGC cylinder feedback position on one side is abnormal, the corresponding position sensor is judged to be abnormal, and the system alarms to remind the operator; Step 2: After the HGC servo control system is in OFF mode, the HGC cylinder position is locked. After the roughing mill completes the current pass, the system program automatically issues instructions, and the next pass is not allowed to feed steel. At the same time, it automatically switches to the normal single-side use of the position sensor. Step 3: After the operator manually switches the HGC servo control system to the ON mode, the roughing mill is allowed to continue rolling steel.

[0007] Furthermore, the system alarm is in the form of a pop-up prompt box on the HMI screen.

[0008] Furthermore, when the feedback position of the HGC cylinder on one side is greater than the rated stroke of the cylinder or the feedback position change speed exceeds 10 mm / s, it is determined that the corresponding position sensor is abnormal.

[0009] Beneficial effects of the present invention: The present invention effectively combines the actual state of the HGC cylinder position sensor and the position control of the HGC cylinder servo control system, and can realize automatic alarm after one of the position sensors of the HGC cylinder is damaged, and prepare for mode switching. The operator only needs to confirm and re-activate the HGC cylinder servo control system to the ON mode to continue steel rolling, which effectively reduces the operating steps of the operator and reduces the unplanned downtime of the rolling line. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present invention are described below.

[0012] like Figure 1 As shown, the present invention provides a method for automatically switching the HGC cylinder position sensor during continuous rolling. During the steel rolling process, when the HGC cylinder servo control system changes to OFF mode and the feedback position of the HGC cylinder on one side is abnormal, the corresponding position sensor is determined to be abnormal, and a prompt box pops up on the HMI screen to remind the operator that the HGC cylinder position sensor is abnormal. At this time, the HGC cylinder position is locked. After the rough rolling mill completes the current pass, the system program automatically issues an instruction that the next pass is not allowed to feed steel; and it automatically switches to the normal single-side use of the position sensor. After the operator manually switches the HGC servo control system to ON mode, the rough rolling mill is allowed to continue rolling steel.

[0013] When two position sensors are used simultaneously, the actual position of the HGC cylinder is: H=(H 入口 +H 出口 ) / 2 When the position sensor automatically switches to single-side use, the actual position of the HGC cylinder is: (1) Inlet position sensor used on one side: H=H 入口 , (2) Exit position sensor unilateral use: H=H 出口 Where: H 入口 —Inlet position sensor detection value, mm; H 出口 —Outlet position sensor detection value, mm; In actual production, when one of the position sensors of the HGC cylinder is damaged, it is switched to another normal position sensor for unilateral use. That is, when the inlet position sensor is damaged, the bilateral use mode is automatically switched to unilateral use of the outlet position sensor; when the outlet position sensor is damaged, the bilateral use mode is automatically switched to unilateral use of the inlet position sensor.

[0014] Taking the damage of the inlet position sensor of the oil cylinder as an example, the following describes the treatment process according to the method of the present invention (embodiment of the present invention) and the prior art method (comparative example of the prior art).

[0015] Embodiment of the present invention: When the inlet position sensor is damaged and an alarm signal is issued, the HGC servo control system is turned OFF and a pop-up box is displayed on the HMI screen to remind the operator. After the rough rolling mill completes the current pass, the next pass is automatically swung. The HGC cylinder position sensor automatically switches from the bilateral use mode to the unilateral use mode of the outlet position sensor. After the operator sees the HGC servo control system OFF pop-up box alarm, he only needs to re-activate the servo control system ON to resume steel rolling. The entire recovery process only requires one operation step and takes about 10 seconds.

[0016] Comparative example of prior art: When the inlet position sensor is damaged, the mode of the HGC cylinder servo control system is OFF, the servo system output is disconnected, and the HGC cylinder position is locked in place and cannot continue to move. After the servo control system is OFF, if the deviation between the set position and the feedback position of the HGC cylinder does not exceed ±0.5mm, steel rolling can continue until the set position of the HGC cylinder changes significantly, and the over-deviation and failure to feed steel are discovered. That is, when the entrance position sensor is damaged, it will only be discovered when there is a problem of no steel feeding. At this time, the operator's operating steps are: ① After the operator finds that the rough rolling mill does not feed steel, he checks the reason for the no steel feeding; ② Then open the HGC servo control system screen and find that the servo system is OFF; ③ The operator opens the HGC cylinder position sensor status screen and finds that the entrance position sensor feedback is abnormal; ④ The operator manually switches the HGC cylinder position sensor mode to the single-sided use of the normal exit position sensor; ⑤ The operator opens the HGC servo control system screen and turns the servo control system ON; ⑥ Because the set position and feedback position exceed ±0.5mm deviation, the operator needs to manually APC again to resume steel rolling. The entire inspection, confirmation and operation process requires 6 operation steps at the fastest and at least 3 minutes. If the operation is improper during the process, it will take too long and the slab temperature will drop a lot, resulting in the slab needing to be returned to the furnace or pushed into long strips.

[0017] By comparing the embodiments and the comparative examples, it can be found that the method of the present invention can reduce 5 operation steps, shorten the recovery time by at least 170 seconds, and avoid the risk of re-melting or pushing long strips.

[0018] The above are only preferred embodiments of the present invention and are 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 in the protection scope of the present invention.

Claims

1. A method for switching the mode of HGC cylinder position sensor during continuous rolling, characterized in that: The following steps are involved: Step 1: During the steel rolling process, when the HGC cylinder servo control system changes to OFF mode and the feedback position of the HGC cylinder on one side is abnormal, the corresponding position sensor is judged to be abnormal, and the system alarms to remind the operator; Step 2: After the HGC servo control system is in OFF mode, the HGC cylinder position is locked. After the roughing mill completes the current pass, the system program automatically issues instructions, and the next pass is not allowed to feed steel. At the same time, it automatically switches to the normal single-side use of the position sensor. Step 3: After the operator manually switches the HGC servo control system to the ON mode, the roughing mill is allowed to continue rolling steel.

2. The method for switching the mode of the HGC oil cylinder position sensor during continuous rolling according to claim 1 is characterized in that: The system alarm is in the form of a pop-up prompt box on the HMI screen.

3. The method for switching the mode of the HGC cylinder position sensor during continuous rolling according to claim 1 or 2, characterized in that: When the feedback position of the HGC cylinder on one side is greater than the rated stroke of the cylinder or the feedback position change speed exceeds 10mm / s, the corresponding position sensor is determined to be abnormal.

Images