Auxiliary tool and method for accuracy control of sendzimir mill

Abstract

The application discloses an auxiliary tool and method for precision control of a Sendzimir mill, wherein an outer thread is arranged at an end of a test roller shaft, a connecting sleeve is connected to the end of the test roller shaft, a support frame is arranged on the connecting sleeve, a box body is welded to a top end of the support frame, and a target ball is arranged in the box body. In the method, the upper and lower work rollers of the mill are replaced by the test roller, the movement track of the target ball is measured by a laser tracker, the spatial position of the test roller shaft is obtained, and thus the quantitative data of the positions of the upper and lower work rollers are obtained; the actual rolling center line is obtained by the rolling center line and the non-abrasion processing surface of the mill housing; whether the perpendicularity of the upper and lower work rollers and the actual rolling center line meets the rolling precision requirement is judged; the adjustment amount of the upper and lower work rollers is obtained according to the quantitative data, and the adjustment is performed; the perpendicularity of the shape measurement roller and the actual rolling center line is adjusted, and the through line is ensured to be horizontal. The auxiliary tool and method provide reliable basis for the mill adjustment, ensure the rolling precision of the mill, and improve the shape quality of the strip steel.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to an auxiliary tool and method for precision control of Sendzimir rolling mills. Background Technology

[0002] The Sendzimir mill is a single-stand reversible cold rolling mill. Its main adjustment methods include roll reduction adjustment and AS-U adjustment. Roll reduction adjustment uses two hydraulic cylinders mounted on the stand to drive two gears at the shaft ends. The gears and eccentric wheels are connected to the support shaft by a key. When the gears rotate, the inner eccentric wheel rotates around the inner eccentric ring, completing the roll reduction function and adjusting the roll gap. AS-U adjustment uses seven hydraulic cylinders to drive seven racks, causing the eccentrics on the B and C shafts of the support rolls to rotate around the center of the support roll saddle. This causes the support shaft to bend, changing the relative height between the various support bearings to adjust the roll gap along the roll axis and ensure the product's shape. Two strip shape measuring rolls are installed at the outlet and inlet of the rolling mill, respectively. Several pressure sensors are installed on the strip shape measuring rolls along the axial direction. During the strip rolling process, the strip is pressed firmly onto the strip shape measuring rolls. Therefore, the output signal of the pressure sensor inside the strip shape measuring rolls changes with the change of strip shape. These signals are processed by the strip shape control system and then act on the hydraulic valve. The action of the hydraulic valve makes a fine adjustment to the eccentric wheel of the support roll. At the same time, these signals also control the lateral movement of the first intermediate roll. In this way, the strip shape is effectively controlled.

[0003] However, as the mill operates, localized wear occurs in the sprue holes of the mill stand. This prevents the AGC control from maintaining the work rolls at the zero position, and even causes the upper and lower work rolls to cross or misalign. Furthermore, the specific spatial location is difficult to determine, and quantitative data is lacking. If the work rolls are not perpendicular to the mill centerline, the strip will deviate. This causes a false pressure reading on the shape measuring roll due to the strip's non-perpendicularity, significantly impacting the overall control system. This makes it impossible to eliminate shape defects through AS-U adjustment, resulting in ineffective shape control. Traditional methods often rely on subjective judgment based on the strip's defect state to fine-tune the mill window position, but the results are unsatisfactory. For example, measuring the sprue hole spacing with an inside micrometer, combined with other local measurements, can help determine the sprue hole wear. However, this method is planar and ineffective for measuring localized spatial locations. Alternatively, a target ball can be used in conjunction with an industrial-grade total station to measure the axis of each plum blossom hole to determine local wear. However, this method requires measuring eight plum blossom holes, resulting in a large workload, and it is difficult to achieve the desired results for production lines with high precision requirements for silicon steel. Therefore, how to accurately measure the spatial position accuracy of the work rolls, measure the center line of the unit, and make effective adjustments is a common challenge. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an auxiliary tool and method for precision control of Sendzimir mill. This auxiliary tool and method directly measures the spatial position of the upper and lower work rolls, the positional relationship between the roll system, the center line of the mill and the center plane of the stand when the reduction is different, so as to provide a reliable basis for mill adjustment, ensure the rolling accuracy of the mill and improve the strip shape quality.

[0005] To solve the above-mentioned technical problems, the present invention provides an auxiliary tool for precision control of Sendzimir mills, comprising a test roll, a connecting sleeve, a support frame, a housing, and a target ball. The test roll has the same diameter and material as the mill work roll, but a longer roll length. An external thread is machined at the end of the test roll shaft. The inner ring of the connecting sleeve has an internal thread and is screwed onto the external thread at the end of the test roll shaft. The support frame has a curved bottom and a flat top, and is vertically welded to the outer ring of the connecting sleeve via the curved bottom surface. The housing is welded to the top flat surface of the support frame, and a window is provided on the side of the housing. The target ball is fixed inside the housing and located at the window position.

[0006] Furthermore, the box body includes a bottom box and a lid. The bottom box and the lid are connected by a shaft and can be opened and closed. After the lid is closed, it is locked to the bottom box by screws on both sides. The box body is made of ferromagnetic material.

[0007] Furthermore, the support frame includes a base plate and reinforcing ribs, and the reinforcing ribs are welded to the surface of the base plate at the center along the length direction of the base plate to form a T-shaped cross section.

[0008] A method for precision control of Sendzimir mills based on the aforementioned auxiliary tools includes the following steps:

[0009] Step 1: Replace the upper and lower work rolls of the rolling mill with the test roll of the auxiliary tool in sequence. Under the conditions of no load on the upper and lower work rolls and pressures of 1000 MPa, 2000 MPa, 3000 MPa and 4000 MPa respectively, measure the motion trajectory of the target ball with a laser tracker to obtain the spatial position of the test roll axis, thereby obtaining quantitative data on the parallelism and misalignment between the upper and lower work rolls.

[0010] Step 2: Collect the permanent reference points buried during the installation of the rolling mill to obtain the rolling center line of the rolling mill. Collect the unworn machining surface of the rolling mill stand. Based on the rolling center line and the unworn machining surface of the rolling mill stand, obtain the actual rolling center line of the rolling mill.

[0011] Step 3: Obtain the perpendicularity of the upper and lower work rolls to the actual rolling centerline based on the actual rolling centerline of the rolling mill, and determine whether the perpendicularity meets the rolling accuracy requirements.

[0012] Step 4: Based on the quantitative data of parallelism and misalignment between the upper and lower work rolls, and in conjunction with the actual plate shape defects, determine the adjustment amount of the upper and lower work rolls. Through the rolling mill control system, adjust the upper and lower work rolls to the zero position to ensure that the upper and lower work rolls are parallel and within the center plane of the rolling mill stand, while being perpendicular to the actual rolling center line.

[0013] Step 5: Adjust the inlet and outlet plate shape measuring rollers to be perpendicular to the actual rolling centerline within the accuracy range of ±0.05mm / m. At the same time, measure the height difference between the two ends of the plate shape measuring rollers to ensure that the plate passage line is horizontal.

[0014] Furthermore, in step one, the test roller rotates in a jogging manner. During the rotation of the test roller, the target ball is set as a measurement point every 15°. The laser tracker measures the target ball's motion trajectory data at each measurement point.

[0015] Because the auxiliary tool and method for precision control of Sendzimir mills in this invention adopts the above-mentioned technical solution, namely, the test roll shaft end of this auxiliary tool is provided with an external thread, the connecting sleeve is connected to the test roll shaft end through the thread, the support frame is vertically set on the outer ring of the connecting sleeve, the box body is welded to the top plane of the support frame, the side of the box body has a window, and the target ball is fixed in the box body and located at the window position. This method uses test rolls to replace the upper and lower work rolls of the mill in sequence. Under different working conditions, the motion trajectory of the target ball is measured by a laser tracker to obtain the spatial position of the test roll axis, thereby obtaining quantitative data on the parallelism and misalignment between the upper and lower work rolls; the actual rolling center line of the mill is obtained through the rolling center line of the mill and the unworn processing surface of the mill stand; it is judged whether the perpendicularity of the upper and lower work rolls to the actual rolling center line meets the rolling accuracy requirements; the adjustment amount of the upper and lower work rolls is obtained according to the quantitative data and adjusted; the perpendicularity of the plate shape measuring roll to the actual rolling center line is adjusted, and the height difference between the two ends of the plate shape measuring roll is measured to ensure that the plate line is horizontal. This auxiliary tool and method directly measures the spatial position of the upper and lower work rolls, the positional relationship between the roll system, the mill centerline and the archway center plane under different reduction amounts, providing a reliable basis for mill adjustment, ensuring the rolling accuracy of the mill, and improving the strip shape quality. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0017] Figure 1 This is a schematic diagram of the auxiliary tool structure for precision control of Sendzimir mills according to the present invention;

[0018] Figure 2 for Figure 1 Side view. Detailed Implementation

[0019] Implementation, for example Figure 1 and Figure 2 As shown, the auxiliary tool for precision control of Sendzimir mills according to the present invention includes a test roll 1, a connecting sleeve 2, a support frame 3, a box 4, and a target ball 5. The test roll 1 has the same roll diameter and material as the mill work roll, but a roll length greater than the mill work roll. The test roll 1 has an external thread machined at its shaft end. The connecting sleeve 2 has an internal thread on its inner ring and is screwed onto the external thread at the shaft end of the test roll 1. The support frame 3 has a rounded bottom and a flat top. The support frame 3 is vertically welded to the outer ring of the connecting sleeve 2 through the rounded bottom surface. The box 4 is welded to the top flat surface of the support frame 3. The box 4 has a window on its side. The target ball 5 is fixed inside the box 4 and located at the window position.

[0020] Preferably, the box body 4 includes a base box 41 and a lid 42. The base box 41 and the lid 42 are connected by a shaft and can be opened and closed. After the lid 42 is closed, it is locked to the base box 41 by screws on both sides. The box body 4 is made of ferromagnetic material. The box structure facilitates the placement and fixation of the target ball and avoids relative displacement of the target ball.

[0021] Preferably, the support frame 3 includes a base plate 31 and reinforcing ribs 32, the reinforcing ribs 32 being centrally welded to the surface of the base plate 31 along its length to form a T-shaped cross-section. The T-shaped cross-section of the support frame effectively improves the rigidity of the support frame, ensuring the consistency of the target ball's trajectory.

[0022] This auxiliary tool consists of a test roller, a connecting sleeve, a support frame, and a box for holding the target ball. The test roller is used to replace the work roller of the rolling mill and simulate the spatial position of the work roller at different reduction amounts during production. The connecting sleeve is used to connect the test roller and the support frame. The support frame is used to increase the radius of the circular plane of the rotating test roller and reduce the impact of measurement errors on the results. The box is used to place and fix the target ball to prevent it from falling off during high-speed rotation.

[0023] A method for precision control of Sendzimir mills based on the aforementioned auxiliary tools includes the following steps:

[0024] Step 1: Replace the upper and lower work rolls of the rolling mill with the test roll of the auxiliary tool in sequence. Under the conditions of no load on the upper and lower work rolls and pressures of 1000 MPa, 2000 MPa, 3000 MPa and 4000 MPa respectively, measure the motion trajectory of the target ball with a laser tracker to obtain the spatial position of the test roll axis, thereby obtaining quantitative data on the parallelism and misalignment between the upper and lower work rolls.

[0025] Step 2: Collect the permanent reference points buried during the installation of the rolling mill to obtain the rolling center line of the rolling mill. Collect the unworn machining surface of the rolling mill stand. Based on the rolling center line and the unworn machining surface of the rolling mill stand, obtain the actual rolling center line of the rolling mill.

[0026] Step 3: Obtain the perpendicularity of the upper and lower work rolls to the actual rolling centerline based on the actual rolling centerline of the rolling mill, and determine whether the perpendicularity meets the rolling accuracy requirements.

[0027] Step 4: Based on the quantitative data of parallelism and misalignment between the upper and lower work rolls, and in conjunction with the actual plate shape defects, determine the adjustment amount of the upper and lower work rolls. Through the rolling mill control system, adjust the upper and lower work rolls to the zero position to ensure that the upper and lower work rolls are parallel and within the center plane of the rolling mill stand, while being perpendicular to the actual rolling center line.

[0028] Step 5: Adjust the inlet and outlet plate shape measuring rollers to be perpendicular to the actual rolling centerline within the accuracy range of ±0.05mm / m. At the same time, measure the height difference between the two ends of the plate shape measuring rollers to ensure that the plate passage line is horizontal.

[0029] Preferably, in step one, the test roller rotates in a jogging manner. During the rotation of the test roller, the target ball is set as a measurement point every 15° angle, and the laser tracker measures the target ball's motion trajectory data at each measurement point.

[0030] This method involves jogging the test roll under different working pressures during measurement, capturing the trajectory of the target ball on the housing. The housing must firmly hold the target ball in place to prevent it from falling off. The test roll simulates the working state of the work rolls under different pressures. Using a laser tracker, the trajectory of the target ball is measured, and the spatial position of the roll system axis is fitted. The quantitative data of the upper and lower work rolls are imported into the analysis software tool, and the least squares method is used to fit the roll system axis. The positional relationship of the axis under different pressures is analyzed, and the state of the upper and lower work rolls is determined by the spatial position of the axis. The spatial position of the upper and lower work rolls is determined by measuring the unworn mounting surface of the mill stand. The spatial position of the mill center plane is obtained by measuring the spatial position of the front and rear shape measuring rolls. Through measurement, adjustment, and re-measurement, the spatial accuracy of the mill is restored.

[0031] Spatial accuracy issues such as the crossing and misalignment of the upper and lower work rolls in Sendzimir mills have consistently and severely impacted operators' control over strip shape, consequently hindering the improvement of strip yield. When the roll system crossing is severe, the strip exhibits significant waviness and increased camber, which cannot be eliminated through AS-U adjustment, making effective strip shape control impossible. This auxiliary tool and method directly measures the spatial position of the upper and lower work rolls, as well as the positional relationship between the roll system, the mill centerline, and the stand center plane at different reduction amounts. Adjustments made to these adjustments restore the mill's rolling accuracy.

[0032] By using auxiliary tools and corresponding control methods, quantitative data on the work rolls can be obtained, resulting in significant adjustments and avoiding the uncertainties associated with previous subjective judgments and fine-tuning of the mill window position. This improves rolling stability and product quality, generating substantial economic benefits. For example, in silicon steel plants, it can increase the yield by approximately 0.51%, with a single unit producing about 96,000 tons annually. Currently, the price of silicon steel coils is approximately 15,000 yuan / ton, meaning the economic benefit per unit is 96,000 tons × 0.51% × 15,000 yuan / ton = 7,344,000 yuan. Simultaneously, it also creates economic benefits to varying degrees by reducing roll consumption and downtime.

Claims

1. A method for precision control of a Sendzimir rolling mill, the auxiliary tools used in this method include a test roll, a connecting sleeve, a support frame, a box body, and a target ball. The test roll has the same roll diameter and material as the rolling mill work roll, but a roll length greater than the rolling mill work roll, and an external thread is machined at the end of the test roll shaft. The inner ring of the connecting sleeve has an internal thread and is screwed onto the external thread at the end of the test roll shaft. The support frame has an arc surface at the bottom and a flat surface at the top, and the support frame is vertically welded to the outer ring of the connecting sleeve through the arc surface at the bottom. The box body is welded to the top flat surface of the support frame, and a window is opened on the side of the box body. The target ball is fixed inside the box body and located at the window position. The box body includes a bottom box and a cover, the bottom box and the cover are connected by a shaft and can be opened and closed. After the cover is closed, it is locked to the bottom box by screws on both sides. The box body is made of ferromagnetic material. The support frame includes a base plate and a reinforcing rib, the reinforcing rib being welded to the surface of the base plate in a T-shaped cross section along the length direction of the base plate. The method is characterized in that... This method includes the following steps: Step 1: Replace the upper and lower work rolls of the rolling mill with the test roll of the auxiliary tool in sequence. Under the conditions of no load on the upper and lower work rolls and pressures of 1000 MPa, 2000 MPa, 3000 MPa and 4000 MPa respectively, measure the motion trajectory of the target ball with a laser tracker to obtain the spatial position of the test roll axis, thereby obtaining quantitative data on the parallelism and misalignment between the upper and lower work rolls. The test roll rotates in a jogging manner. During the rotation of the test roll, the target ball is set as a measurement point every 15°. The laser tracker measures the motion trajectory data of the target ball at each measurement point. Step 2: Collect the permanent reference points buried during the installation of the rolling mill to obtain the rolling center line of the rolling mill. Collect the unworn machining surface of the rolling mill stand. Based on the rolling center line and the unworn machining surface of the rolling mill stand, obtain the actual rolling center line of the rolling mill. Step 3: Obtain the perpendicularity of the upper and lower work rolls to the actual rolling centerline based on the actual rolling centerline of the rolling mill, and determine whether the perpendicularity meets the rolling accuracy requirements. Step 4: Based on the quantitative data of parallelism and misalignment between the upper and lower work rolls, and in conjunction with the actual plate shape defects, determine the adjustment amount of the upper and lower work rolls. Through the rolling mill control system, adjust the upper and lower work rolls to the zero position to ensure that the upper and lower work rolls are parallel and within the center plane of the rolling mill stand, while being perpendicular to the actual rolling center line. Step 5: Adjust the inlet and outlet plate shape measuring rollers to be perpendicular to the actual rolling center line within the accuracy range of ±0.05mm / m. At the same time, measure the height difference between the two ends of the plate shape measuring rollers to ensure that the plate passage line is horizontal.

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