Method for improving roll changing efficiency of six-high CVC cold rolling mill

Abstract

This invention relates to the field of cold rolling technology, and in particular to a method for improving the roll changing efficiency of a six-roll CVC cold rolling mill. The method includes entering roll changing mode and simultaneously opening the roller shutter door; simultaneously retracting the inlet and outlet anti-tangling guides, releasing the HGC (High-Gas Crusher), and lowering the wedge, while moving the roll changing trolley and roll changing carriage to the waiting position; raising the balance hydraulic cylinder in the order of intermediate rolls first, then work rolls; axial movement of the rolls and positioning of the drive shaft are performed synchronously, and the roll changing trolley is driven into the stand; simultaneously locking, unlocking, opening the carriage, unlocking the lock, and opening the oil-air lubrication interface are performed to complete roll removal and loading; the roll changing trolley and carriage exit the stand to the waiting position, and the rolls move to the calibration position; entering calibration mode and using the calibration time to move the roll changing trolley and carriage to the final position and complete the lateral movement of the old rolls; after calibration, switching to operating mode, and the roll changing ends. This invention improves the roll changing efficiency of a six-roll CVC cold rolling mill, and the method is simple, safe, and efficient.

Description

Technical Field

[0001] This invention relates to the field of cold rolling technology, and in particular to a method for improving the roll changing efficiency of a six-roll CVC cold rolling mill. Background Technology

[0002] Roll changing, a critical operation in the production of a six-high CVC cold rolling mill, has a significant impact on the mill's efficiency. Improving roll changing efficiency is essentially equivalent to improving the overall mill efficiency. However, due to the increasing service life of the mill, coupled with equipment aging and outdated control systems, the impact of low roll changing efficiency on mill efficiency becomes increasingly pronounced.

[0003] Currently, there is limited research on improving the roll changing efficiency of six-roll CVC cold rolling mills. The Chinese patent CN116441317A, "Method for Improving Roll Changing Efficiency of Cold Rolling Mills," and the paper "Influencing Factors and Improvement Measures for Roll Changing in Cold Continuous Rolling Mills," published on July 31, 2024, in Shanxi Metallurgy 2024, 47(07), both aim to improve roll changing efficiency by optimizing the roll changing procedure and system capabilities. However, the roll changing procedure and control system capabilities are already established at the beginning of the mill's design and manufacturing, requiring equipment upgrades and modifications. This also involves a large amount of debugging that affects operational efficiency, inevitably increasing R&D and equipment costs.

[0004] In conclusion, there is an urgent need for a method that can utilize existing equipment functions, without increasing production costs, and is easy to popularize and implement, to improve the roll changing efficiency of a six-roll CVC cold rolling mill. Summary of the Invention

[0005] This invention provides a method for improving the roll changing efficiency of a six-roll CVC cold rolling mill. Utilizing existing equipment and functions, the method improves the roll changing efficiency of the six-roll CVC cold rolling mill by optimizing the operation process without increasing production costs. The method is simple to operate and achieves safe and efficient roll changing operations.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A method for improving the roll changing efficiency of a six-roll CVC cold rolling mill includes the following steps: S1. Enter the roll changing mode, select the type of roll to be replaced, and open the rolling mill shutter door at the same time; S2. Simultaneously execute the retraction of the inlet and outlet anti-tangling guide plates, the release of HGC, and the descent of the inclined wedge. During this action, the roll changing trolley is moved to the waiting position, and the roll changing carriage is moved to the foremost position of the roll lateral movement position. S3. First lift the intermediate roller balancing hydraulic cylinder, then lift the work roller balancing hydraulic cylinder; S4. Move the work roll and intermediate roll axially to the roll changing position, and simultaneously position the drive shaft. During this period, drive the roll changing trolley into the frame to the roll changing position. If only the work roll is being replaced, the drive shaft positioning step is not required. S5. After the axial movement of the work roll and intermediate roll and the positioning of the drive shaft are completed, simultaneously lock the drive shaft and unlock the drive shaft connection. Simultaneously execute locking the roll changing trolley, opening the roll changing trolley, unlocking the work roll and intermediate roll and the oil-air lubrication interface, and then complete the old roll extraction and new roll push-in by cooperating with the roll changing trolley and the roll changing trolley. S6. When the roll changing trolley exits the frame and reaches the waiting position, the drive shaft connection locking and unlocking operations are completed simultaneously. The work roll and intermediate roll are axially moved to the calibration position, and the new roll data is confirmed, submitted and uploaded. S7. Raise the wedge, switch to calibration mode, start calibration, and close the roller shutter door; S8. Using the calibrated time, move the roll changing trolley and roll changing carriage that are waiting to the final limit position and move the old work roll laterally to the hoisting side. S9. After calibration is complete, switch to running mode and the roll change is finished.

[0007] Furthermore, the type of roll replacement includes replacing the work roll or replacing both the work roll and the intermediate roll simultaneously.

[0008] Furthermore, in step S2, the waiting position is 0.8 to 1m in front of the roller shutter door.

[0009] Furthermore, step S4 also includes not locking the roll changing trolley before the positioning of the roller shifting and drive shaft is completed, and keeping the roll changing trolley stationary.

[0010] Furthermore, step S5 involves the old roll being pulled out and the new roll being pushed in through the cooperation of the roll-changing trolley and the roll-changing carriage. Specifically, after the roll-changing trolley moves to the roll-pulling position, the hook of the roll-changing trolley is engaged to hook the work roll and the upper intermediate roll, and they are pulled out into the roll lateral movement position. Then, the hook of the roll-changing trolley is opened, and the roll-changing trolley is moved out of the roll lateral movement position. The roll-changing carriage is unlocked, and the roll-changing hook on the roll-changing carriage is engaged to hook the lower intermediate roll, pull it out, and release the hook to make room for the hoisting. After completing the hoisting and replacement of the lower intermediate roll, simultaneously operate the roll changing trolley to push the lower intermediate roll into the mill stand and move the rolls laterally. Once in position, lock the roll changing trolley. Use the roll changing trolley to push the spare new work roll and upper intermediate roll into the mill stand. Close the locks and oil-air lubrication interfaces of the work roll and intermediate roll. After confirming that they are closed, withdraw the roll changing trolley to the waiting position. At the same time, operate the unlocking roll changing trolley and withdraw the roll changing trolley to the waiting position outside the stand. If only the work roll is being replaced, the step of operating the intermediate roll is omitted.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention significantly improves the efficiency of roll changing operations. Without updating equipment or upgrading the system, it combines the actual site conditions, analyzes and configures the roll changing device and roll changing control timing, optimizes the timing matching and connection of roll changing control during the roll changing process, and finally achieves efficient optimization of the production process. At the same time, it also improves the efficiency of production operations and reduces the average roll changing time by 33%. Attached Figure Description

[0012] Figure 1 This is a flowchart of the method described in this invention. Detailed Implementation

[0013] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: Roll changing is a crucial step in steel rolling production. Efficient roll changing operations can significantly improve overall efficiency. This invention proposes a method to improve the roll changing efficiency of a six-roll CVC cold rolling mill, specifically addressing the work roll and intermediate roll changes. (See attached document.) Figure 1 This is a flowchart of the method of the present invention, which specifically includes the following steps: S1. Enter roll changing mode, select the roll to be replaced, the work roll or the work roll and intermediate roll to be replaced at the same time, and you can open the rolling mill shutter door to wait for roll changing.

[0014] S2, the three steps of inlet and outlet anti-tangling guide plate retraction, HGC release, and wedge descent are independent and can be performed simultaneously. This step requires a certain amount of time to complete. During this time, the roll changing trolley can be moved to the waiting position 1m in front of the roller shutter door, which is the minimum distance that will not affect the operation of the equipment inside the frame. At the same time, the roll changing trolley can be moved to the foremost position of the roll lateral movement position. This position is the minimum distance that the roll changing trolley will not affect the subsequent roll changing operation.

[0015] S3. The intermediate roll and work roll balancing hydraulic cylinders are raised. It is important to note that the intermediate roll balancing is operated first, followed by the work roll balancing. This is because the lifting position of the work roll balancing cylinder is restricted before the intermediate roll balancing cylinder is raised, and there is not enough stroke space, which can easily cause equipment to scrape and damage the equipment, and can also cause unnecessary roll changing delays.

[0016] S4. The work roll and intermediate roll are axially moved to the roll changing position. The drive shaft positioning can be performed simultaneously with the axial roll movement step, without conflict and saving time. This step requires a certain amount of time. Since the movement of the work roll and intermediate roll at this time does not affect the entry of the roll changing trolley into the frame, the roll changing trolley can be fully driven into the frame to the roll changing position at this time, which can further improve the work efficiency. However, the roll changing trolley cannot be locked before the roll movement and drive shaft positioning are completed, and the roll changing trolley must be kept stationary. Otherwise, the axial movement of the work roll and intermediate roll and the drive shaft positioning step will not be completed. When only the work roll is being replaced, the drive shaft positioning step is not required.

[0017] S5. After the axial movement of the work roll and intermediate roll and the positioning of the drive shaft are completed, simultaneously lock and unlock the drive shaft connection. After the above steps are completed, simultaneously lock the roll changing trolley, move the roll changing carriage, and unlock the work roll, intermediate roll, and oil-air lubrication interface. After confirming that they are open, move the roll changing carriage to the roll pulling position, operate the roll changing carriage hook to hook the work roll and upper intermediate roll, and pull them out to the roll lateral movement position. Then open the roll changing carriage hook and move the roll changing carriage back to outside the roll lateral movement position. Unlock the roll changing trolley and operate the roll changing carriage... The roll-changing hook hooks the lower intermediate roll, pulls it out, and releases the hook to make room for the hoisting. The lower intermediate roll is then hoisted and replaced. At the same time, the roll-changing trolley is operated to push the lower intermediate roll into the mill stand and the rolls are moved laterally. Once in place, the roll-changing trolley is locked. The roll-changing trolley is then used to push the spare new work roll and the upper intermediate roll into the mill stand. The locks and oil-air lubrication interfaces of the work roll and intermediate roll are closed. After confirming that they are closed, the roll-changing trolley is withdrawn to the waiting position. At the same time, the roll-changing trolley is unlocked and withdrawn to the waiting position outside the stand. If only the work roll is replaced, the relevant steps for the intermediate roll are not required.

[0018] S6. When the roll changing trolley exits the frame and reaches the waiting position, and the drive shaft connection locking and unlocking operations are completed, the calibration preparation steps can be carried out. First, the work roll and intermediate roll are axially moved to the calibration position without interfering with each other. During the axial movement of the work roll and intermediate roll, the new roll data is confirmed, submitted, and uploaded to avoid affecting the next step of the operation due to data problems.

[0019] S7. Raise the wedge, switch to calibration mode, start calibration, and close the roller shutter door.

[0020] S8. Using the calibrated time, move the roll changing trolley and roll changing carriage that are waiting in the waiting position to the final limit position, and move the old work roll laterally to the side that is easy to lift. This will make the lifting efficiency higher.

[0021] S9. Calibration complete, switch to operating mode, roll change complete.

[0022] It should be noted that when changing the intermediate roll, the intermediate roll needs to be hoisted on site, so it is necessary to prepare an overhead crane in advance to facilitate the process and improve efficiency.

[0023] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0024] Example: There are two optimal implementation methods for the roll changing optimization scheme of a six-roll CVC cold rolling mill: changing the work roll and changing both the work roll and the intermediate roll. The surface shows an embodiment using the method of this invention: Method for changing the work roll: first step: 1. Enter the roll changing mode and select to change the work roll; 2. Open the rolling mill shutter door; Optimized features: Both operations can be performed simultaneously, improving work efficiency.

[0025] Step Two: 1. Simultaneously operate the inlet and outlet anti-tangling guide plate retraction, HGC release, and wedge descent; 2. Utilize the above equipment operation time to move the roll changing trolley to 1m in front of the roller shutter door (waiting position), and move the roll changing trolley to the foremost position of the roll lateral movement. Optimization content: 1. The inlet and outlet anti-tangling guide plates retract, HGC is released, and the wedge descends simultaneously without interference, resulting in higher efficiency; 2. By utilizing the above-mentioned equipment operation process, the roller changing trolley and roller changing carriage can be moved to the foremost position that does not affect the roller changing operation, which can improve the operation efficiency.

[0026] Step 3: 1. First, lift the intermediate roller balancing hydraulic cylinder; 2. The rear work roll balancing hydraulic cylinder is raised; Optimization: Operate in sequence, otherwise there is a risk of damaging the equipment.

[0027] Step 4: 1. Simultaneously move the work roll and intermediate roll axially to the roll changing position; 2. Move the roll changing trolley to the roll changing position, keeping the roll changing trolley unlocked and the roll changing carriage stationary. Optimization content: 1. The axial movement of the work roll and the intermediate roll does not interfere with each other, and the operating efficiency is higher.

[0028] 2. By utilizing the movement of the work roll and intermediate roll, the roll changing trolley can be moved to the roll changing position simultaneously, saving more operation time.

[0029] Step 5: 1. Once the axial movement of the roll is completed, simultaneously operate the locking roll changing trolley, move the roll changing carriage in, and open the work roll lock and oil-air lubrication interface; 2. The roll-changing trolley moves to the roll-pulling position, and the work roll hook hooks onto the work roll and pulls it out to the roll lateral movement position; 3. Open the hook of the roll changing trolley, retract the roll changing trolley to outside the roll lateral movement position, move the roll changing trolley laterally, and push the new work roll into the frame using the roll changing trolley after it is in place; 4. Close the work roll lock and oil-air lubrication interface, move the roll changing trolley to the front of the roll lateral movement position, unlock the roll changing trolley, and move it to the waiting position outside the frame; Optimization content: 1. Locking the roll changing trolley, opening the roll changing carriage, and opening the lock and oil-air lubrication interface of the work roll can achieve synchronous operation, which makes the efficiency higher.

[0030] 2. The operation of the loading and unloading rollers should be continuous to save more time.

[0031] 3. Closing the work roll lock and oil-air lubrication interface, as well as the withdrawal of the roll changing trolley and roll changing carriage, can be done simultaneously. The trolley only needs to be withdrawn to the waiting position, and the carriage only needs to be withdrawn to the foremost position of the roll lateral movement. This will not affect subsequent operations and can also improve work efficiency.

[0032] Step 6: 1. Simultaneously move the work roll and intermediate roll axially to the calibrated position; 2. Utilize the equipment's operating time to confirm, submit, and upload the new roll data; Optimization content: 1. The axial movement of the work roll and the intermediate roll does not interfere with each other, and the operating efficiency is higher.

[0033] 2. By utilizing the movement of the work roll and intermediate roll, the confirmation, submission, and uploading of new roll data can be completed simultaneously, thus avoiding calibration failures caused by data issues.

[0034] Step 7: 1. Raise the wedge and switch to calibration mode; 2. Press the calibration button to begin calibration; Optimization content: Pay attention to the equipment status inside the mill stand during the initial stage of calibration, and stop operation immediately if any abnormality is found.

[0035] Step 8: 1. The roller changing trolley and carriage reach their final limit positions during operation; 2. Move the old work roller to the other side; 3. Close the roller shutter door; Optimization content: 1. By utilizing calibration during the process, the return of the roller changing carriages to their original positions can be completed simultaneously, making parallel operations more time-saving.

[0036] 2. Moving the old work roller to the other side makes hoisting easier.

[0037] 3. At this point, the calibration process is nearing completion, and the roller shutter door can be closed.

[0038] Step 9: Calibration complete, switch to operating mode, and roll change complete.

[0039] Methods for changing work rolls and intermediate rolls: first step: 1. Enter the roll changing mode and select the intermediate roll replacement mode; 2. Open the rolling mill shutter door; Optimized features: Both operations can be performed simultaneously, improving work efficiency.

[0040] Step Two: 1. Simultaneously operate the inlet and outlet anti-tangling guide plate retraction, HGC release, and wedge descent; 2. Utilize the above equipment operation time to move the roll changing trolley to 1m in front of the roller shutter door (waiting position), and move the roll changing trolley to the foremost position of the roll lateral movement. Optimization content: 1. The inlet and outlet anti-tangling guide plates retract, HGC is released, and the wedge descends simultaneously without interfering with each other, resulting in higher efficiency.

[0041] 2. By utilizing the above-mentioned equipment operation process, the roller changing trolley and roller changing carriage can be moved to the foremost position that does not affect the roller changing operation, which can improve the operation efficiency.

[0042] Step 3: 1. The intermediate roller balancing hydraulic cylinder is raised; 2. The rear work roll balancing hydraulic cylinder is raised; Optimization: Operate in sequence, otherwise there is a risk of damaging the equipment.

[0043] Step 4: 1. Simultaneously operate the work roll and intermediate roll to move axially to the roll changing position and position the drive shaft; 2. Move the roll changing trolley to the roll changing position, keeping the roll changing trolley unlocked and the roll changing carriage stationary. Optimization content: 1. The axial movement of the working roller, the axial movement of the intermediate roller, and the positioning of the drive shaft do not affect each other and can be operated simultaneously, resulting in higher efficiency.

[0044] 2. By utilizing the movement of the work roll and intermediate roll, the movement of the roll changing trolley can be completed simultaneously, saving more operation time.

[0045] Step 5: 1. Once the axial movement of the roll and the positioning of the drive shaft are completed, simultaneously lock and unlock the drive shaft connection. 2. Lock the roll changing trolley, move the roll changing carriage in, and open the locks on the work roll and intermediate roll, as well as the oil-air lubrication interface; 3. The trolley to be replaced moves to the roller pulling position, and the hooks of the work roller and the intermediate roller hook onto the work roller and the upper intermediate roller and pull them out to the roller replacement lateral movement position. 4. Open the hook of the roll changing trolley, retract the roll changing trolley to outside the roll lateral movement position, unlock the roll changing trolley, operate the roll changing hook on the roll changing trolley to pull out the lower intermediate roll to the hoisting position, release the roll changing hook to make room for hoisting, and complete the hoisting and replacement of the intermediate roll. 5. Simultaneously operate the roll changing trolley to push the lower intermediate roll into the mill stand and the transverse roll to move laterally. After it is in place, lock the roll changing trolley and use the roll changing carriage to push the new work roll and the upper intermediate roll into the mill stand. 6. Close the locks on the work roll and intermediate roll and the oil-air lubrication interface, move the roll changing trolley to the front of the roll lateral movement position, unlock the roll changing trolley, and move it to the waiting position outside the frame; Optimization content: 1. Locking the roll changing trolley, opening the roll changing carriage, and unlocking the work roll, intermediate roll, and oil-air lubrication interface can achieve synchronous operation and higher efficiency.

[0046] 2. The operation of the loading and unloading rollers should be continuous to save more time.

[0047] 3. Closing the work roll, intermediate roll lock, and oil-air lubrication interface, as well as withdrawing the roll changing trolley, can be done simultaneously. The trolley only needs to retreat to the waiting position, and the carriage only needs to retreat to the foremost position of the roll lateral movement. This will not affect subsequent operations and can also improve work efficiency.

[0048] Step 6: 1. First lock the drive shaft connection, then unlock the drive shaft; 2. Simultaneously move the work roll and intermediate roll axially to the calibrated position; 3. Utilize the equipment's operating time to confirm, submit, and upload the new roll data; Optimization content: 1. Lock the drive shaft connection first, then unlock it. Otherwise, the equipment may be damaged.

[0049] 2. The axial movement of the work roll and the intermediate roll does not interfere with each other, and the operating efficiency is higher.

[0050] 3. By utilizing the movement of the work roll and intermediate roll, the confirmation, submission, and uploading of new roll data can be completed simultaneously, thus avoiding calibration failures caused by data issues.

[0051] Step 7: 1. Raise the wedge and switch to calibration mode; 2. Press the calibration button to begin calibration; Optimization content: Pay attention to the equipment status inside the mill stand during the initial stage of calibration, and stop operation immediately if any abnormality is found.

[0052] Step 8: 1. Move the roller changing trolley and carriage to their final limit positions; 2. Move the old work roller to the other side; 3. Close the roller shutter door; Optimization content: 1. By utilizing calibration during the process, the return of the roller changing carriages to their original positions can be completed simultaneously, making parallel operations more time-saving.

[0053] 2. Moving the old work roller to the other side makes hoisting easier.

[0054] 3. At this point, the calibration process is nearing completion, and the roller shutter door can be closed.

[0055] Step 9: Calibration complete, switch to operating mode, and roll change complete.

[0056] Under the premise of ensuring the safety of personnel and equipment, the existing equipment capacity is fully utilized without increasing any production costs. By analyzing and refining the actual situation on site, the timing of the operation logic is optimized, thereby improving the roll changing efficiency. The implementation of this optimization scheme has improved the roll changing efficiency of the six-roll CVC cold rolling mill used in the experiment by 33%, which is very significant.

Claims

1. A method for improving the roll changing efficiency of a six-roll CVC cold rolling mill, characterized in that, Includes the following steps: S1. Enter the roll changing mode, select the type of roll to be replaced, and open the rolling mill shutter door at the same time; S2. Simultaneously execute the retraction of the inlet and outlet anti-tangling guide plates, the release of HGC, and the descent of the inclined wedge. During this action, the roll changing trolley is moved to the waiting position, and the roll changing carriage is moved to the foremost position of the roll lateral movement position. S3. First lift the intermediate roller balancing hydraulic cylinder, then lift the work roller balancing hydraulic cylinder; S4. Move the work roll and intermediate roll axially to the roll changing position, and simultaneously position the drive shaft. During this period, drive the roll changing trolley into the frame to the roll changing position. If only the work roll is being replaced, the drive shaft positioning step is not required. S5. After the axial movement of the work roll and intermediate roll and the positioning of the drive shaft are completed, simultaneously lock the drive shaft and unlock the drive shaft connection. Simultaneously execute locking the roll changing trolley, opening the roll changing trolley, unlocking the work roll and intermediate roll and the oil-air lubrication interface, and then complete the old roll extraction and new roll push-in by cooperating with the roll changing trolley and the roll changing trolley. The old roll is pulled out and the new roll is pushed in by the cooperation of the roll changing trolley and the roll changing trolley. Specifically: when the roll changing trolley is driven to the roll pulling position, the hook of the roll changing trolley is operated to hook the work roll and the upper intermediate roll and pull them out into the roll lateral movement position. Then the hook of the roll changing trolley is opened and the roll changing trolley is moved out of the roll lateral movement position. The roll changing trolley is unlocked and the roll changing hook on the roll changing trolley is operated to hook the lower intermediate roll and pull it out and release the hook to make room for hoisting. The lower intermediate roll is hoisted and replaced. At the same time, the roll changing trolley is operated to push the lower intermediate roll into the mill stand and the roll lateral movement. After it is in place, the roll changing trolley is locked. The spare new work roll and the upper intermediate roll are pushed into the mill stand by the roll changing trolley. The locks and oil-gas lubrication interfaces of the work roll and intermediate roll are closed. After confirming that they are closed, the roll changing trolley is withdrawn to the waiting position. At the same time, the roll changing trolley is unlocked and the roll changing trolley is withdrawn to the waiting position outside the stand. When only the work roll is replaced, the step of operating the intermediate roll is omitted. S6. When the roll changing trolley exits the frame and reaches the waiting position, the drive shaft connection locking and unlocking operations are completed simultaneously. The work roll and intermediate roll are axially moved to the calibration position, and the new roll data is confirmed, submitted and uploaded. S7. Raise the wedge, switch to calibration mode, start calibration, and close the roller shutter door; S8. Using the calibrated time, move the roll changing trolley and roll changing carriage that are waiting to the final limit position and move the old work roll laterally to the hoisting side. S9. After calibration is complete, switch to running mode and the roll change is finished.

2. The method for improving the roll changing efficiency of a six-roll CVC cold rolling mill according to claim 1, characterized in that, The types of roll replacements include replacing the work rolls or replacing both the work rolls and intermediate rolls simultaneously.

3. The method for improving the roll changing efficiency of a six-roll CVC cold rolling mill according to claim 1, characterized in that, In step S2, the waiting position is 0.8 to 1m in front of the roller shutter door.

4. The method for improving the roll changing efficiency of a six-roll CVC cold rolling mill according to claim 1, characterized in that, Step S4 also includes keeping the roll changing trolley stationary until the positioning of the roller shifting and drive shaft is completed, without locking the roller changing trolley.

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