Roller axis parallelism determination and correction method
By pre-setting reference points on the mill stand and measuring the gap with straight rods, combined with geometric derivation and dynamic verification, the problem of determining the parallelism of the roll axis in steel rolling production was solved. This achieved low-cost, efficient, and accurate roll correction, preventing equipment failures and extending equipment service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI XINJIN IRON & STEEL CO LTD
- Filing Date
- 2026-06-10
- Publication Date
- 2026-07-10
AI Technical Summary
Existing technologies lack intuitive, simple, and single-person-capable methods for determining the parallelism of roll axes in steel rolling production, resulting in high inspection costs, low efficiency, poor accuracy, and difficulty in preventing roll crossing problems, which affects production continuity and equipment lifespan.
By setting a reference point on the mill stand, measuring the gap using a straight rod across the pressure, calculating the gap difference using geometric derivation, and correcting the parallelism of the roll axis by adjusting the thickness of the shims, and ensuring the adjustment effect through dynamic verification, the system is simplified into a closed-loop control of static judgment and dynamic verification.
It enables low-cost, fast, and accurate determination and correction of roll axis parallelism, reduces equipment downtime, improves adjustment efficiency and accuracy, prevents accidents such as bearing overheating and burning and strip misalignment, and extends equipment service life.
Smart Images
Figure CN122352684A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metallurgical rolling mill equipment maintenance technology, and particularly relates to a method for determining and correcting the parallelism of the roll axis. Background Technology
[0002] In the steel rolling process, non-parallelism of roll axes (i.e., crossover of two rolls) is a core cause of abnormal roll shifting, bearing overheating and burnout, strip deviation and edge scraping, and even steel pile-up and shutdown, seriously affecting production continuity and equipment lifespan. Currently, the mainstream roll alignment methods on-site mainly include: offline measurement using high-precision testing instruments such as laser trackers, theodolites, dial indicators, and dedicated alignment supports; or manual static gap measurement using feeler gauges and dial indicators. During routine inspections, operators typically rely solely on hearing, vibration, or experience to judge the roll's operating status, lacking quantitative assessment methods.
[0003] However, these traditional methods have many technical drawbacks: First, they heavily rely on high-precision testing instruments such as laser trackers, theodolites, dial indicators, and dedicated alignment supports. This results in high equipment procurement and maintenance costs, long preparation times before testing, and cumbersome testing procedures, often requiring multiple operators and even disassembling the mill cover, leading to prolonged equipment downtime and severely impacting production efficiency. Second, once a deviation in the roll axis is detected, adjusting the liner thickness usually relies on the experience of the staff, lacking quantitative basis and resulting in repeated trial adjustments. This leads to low efficiency, poor accuracy, and difficulty in eliminating roll crossing problems at their root. Daily inspections lack intuitive, simple, and independently operable methods for determining roll crossing, making it impossible to prevent or predict accidents such as bearing burnout and steel pile-up. Furthermore, existing calibration methods generally lack subsequent high-precision verification, relying solely on gap measurements under static shutdown conditions to determine the adjustment effect. This can easily lead to situations where the static condition meets standards, but roll misalignment or deviation persists during dynamic operation, causing recurring failures.
[0004] Therefore, developing a simple, intuitive, and easily operable method for determining and correcting the parallelism of roll axes, capable of quantitative correction and dynamic closed-loop verification, is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] The purpose of this invention is to provide a method for determining and correcting the parallelism of roll axes to solve the above-mentioned problems.
[0006] To achieve the above objectives, the present invention provides the following solution:
[0007] A method for determining and correcting the parallelism of a roll axis includes the following steps:
[0008] Step 1: Pre-set the first, second, third, and fourth reference points on the rolling mill stand. The four reference points are coplanar and form a fixed reference plane.
[0009] Step 2: Using a straight rod, press it across the surfaces of the upper and lower rolls along the first and second diagonal directions respectively. During the pressing, the straight rod should simultaneously contact the surfaces of both the upper and lower rolls, wherein:
[0010] When the rod is pressed across the first diagonal direction, the first end of the rod points to the first reference point and the second end points to the second reference point.
[0011] When the rod is pressed across the second diagonal direction, the first end of the rod points to the third reference point and the second end points to the fourth reference point.
[0012] Step 3: Measure the gap between the first end of the straight rod and the first reference point, and the gap between the second end and the second reference point during the first span compression, to obtain the first gap value and the second gap value; measure the gap between the first end of the straight rod and the third reference point, and the gap between the second end and the fourth reference point during the second span compression, to obtain the third gap value and the fourth gap value.
[0013] Step 4: Calculate the absolute value of the difference between the sum of the first gap value and the second gap value and the sum of the third gap value and the fourth gap value. When the absolute value of the difference is not greater than a preset threshold, determine that the center lines of the upper roll and the lower roll are coplanar. When the absolute value of the difference is greater than the preset threshold, adjust the thickness of one set of diagonal shims so that the sum of the thickness adjustments of this set of shims equals the absolute value of the difference, while keeping the other set of diagonal shims unchanged. Then, remeasure the four gap values and calculate the absolute value of the difference until the absolute value of the adjusted difference is not greater than the preset threshold. The shims are located between the bearing housing used to support the upper roll or the lower roll and the mill stand.
[0014] Furthermore, the absolute value of the difference in step four is ,in, , , , These are the first gap value, second gap value, third gap value, and fourth gap value obtained in step three, respectively; the preset threshold is... .
[0015] Furthermore, the preset threshold is The value range is 0.05mm to 0.10mm.
[0016] Furthermore, the phrase "adjusting the thickness of only one set of diagonal shims" means: when At that time, reduce the number of shims in the first diagonal direction. Alternatively, add shims to each of the second diagonal directions. ;when At that time, increase the number of shims in the first diagonal direction. Alternatively, reduce the number of shims in the second diagonal direction. ;in , .
[0017] Furthermore, the straight rod is connected to the upper and lower rolls via magnetic attraction.
[0018] Furthermore, a feeler gauge is used to measure the gap in step three.
[0019] Furthermore, it also includes dynamic verification and acceptance steps:
[0020] Step 5: After completing the shim adjustment in Step 4, first release the axial limit, and then adjust the vertical clearance to make the vertical clearance between the operating side and the transmission side equal.
[0021] Step 6: Apply lubricant indicator to the surface of the upper roll, and allow the upper and lower rolls to run without load. Observe the axial movement direction of the upper and lower rolls and whether a spiral line appears on the roll surface. When axial movement exists, the rotation of the upper and lower rolls will squeeze the lubricant indicator, causing it to form a spiral line on the roll surface.
[0022] Step 7: When axial movement is observed, adjust the shims according to the actual movement direction of the upper roll and the predefined orientation rules;
[0023] The orientation rules are as follows: with the operating side facing the mill as the reference, the left side of the upper roll and the lower roll is the front side, and the right side of the upper roll and the lower roll is the rear side. The rotation direction of the upper roll is counterclockwise, and the rotation direction of the lower roll is clockwise. The upper roll is supported by the upper bearing seat on the operating side of the upper roll and the upper bearing seat on the drive side of the upper roll, and the lower roll is supported by the lower bearing seat on the operating side of the lower roll and the lower bearing seat on the drive side of the lower roll.
[0024] If the rotation direction of the upper roll causes the upper roll to tend to move radially forward and axially toward the transmission side, increase the shim located on the front side between the upper bearing seat on the operating side of the upper roll and the mill stand, or decrease the shim located on the front side between the upper bearing seat on the transmission side of the upper roll and the mill stand.
[0025] If the rotation direction of the upper roll causes the upper roll to tend to move radially to the rear and axially to the operating side, reduce the shim located on the front side between the upper bearing seat on the operating side of the upper roll and the mill stand, or increase the shim located on the front side between the upper bearing seat on the drive side of the upper roll and the mill stand.
[0026] Repeat steps six and seven until there is no more movement and no spiral lines;
[0027] Step 8: Restore the axial limit, allow the upper and lower rolls to run idle, confirm that there is no roll slippage or abnormal noise, and perform strip rolling test to confirm that the strip does not deviate.
[0028] Furthermore, the method for adjusting the vertical gap in step five is as follows:
[0029] For hot rolling, the soft copper rod is placed into the roll gap on the operating side and the drive side respectively. After pressing down the upper and lower rolls, the thickness difference between the two ends of the soft copper rod is measured, and the vertical gap is adjusted until the thickness difference on both sides is equal.
[0030] For cold rolling, apply a lubricant indicator to the center of the upper roll surface, keep the roll in axial position and allow it to idle, and observe the spread of the lubricant indicator to both ends of the upper and lower rolls. When the spread length is consistent and the thickness is uniform, the vertical gap is determined to be equal; otherwise, continue to adjust until the spread is uniform.
[0031] Compared with the prior art, the present invention has the following advantages and technical effects:
[0032] (1) This invention uses a coplanar reference point pre-set on the mill stand as a fixed reference plane, and a straight rod to measure the gap across two diagonal directions. This transforms the abstract judgment of the parallelism of the roll axis into an intuitive calculation of the gap difference. The entire static judgment process can be completed with only a straight rod and a feeler gauge. No laser tracker, theodolite, dial indicator or any special testing tooling is required. This not only greatly reduces the testing cost, but also allows a single person to complete the operation in a short time, effectively shortening the equipment downtime.
[0033] (2) This invention adjusts the thickness of only one set of diagonally opposite shims so that the sum of the thickness adjustments of that set of shims equals the absolute value of the difference, while keeping the other set unchanged. Furthermore, a quantitative shim adjustment formula is derived based on geometric derivation, namely, based on half the absolute value of the difference between the two sets of gaps (…). Determine the unilateral correction amount, and adjust only one set of diagonal shims (increasing or decreasing each shim in this set). (The other set remains unchanged), avoiding the repeated disassembly and trial adjustment problems caused by traditional experience estimation, and achieving static calibration in one go, significantly improving adjustment efficiency and accuracy. At the same time, the preset threshold can be flexibly selected within the range of 0.05mm to 0.10mm according to the thickness of the available shims on site, taking into account both engineering feasibility and adjustment accuracy.
[0034] (3) This invention adds a dynamic verification step after static correction. First, the vertical gap between the operating side and the transmission side is equal by adjusting the vertical gap (using the soft copper rod insertion method for hot rolling and observing the expansion uniformity by applying lubricating agent in the middle and idling). Then, lubricating agent is applied to the roll surface, the axial limit is released, and the roll is idled. The physical phenomenon of the axial movement of the roll squeezing the lubricating agent to form a spiral when it rotates is used to visually expose the residual cross-section. Finally, the shims are directly adjusted according to the actual movement direction of the upper roll. The entire verification process does not require complex instruments and can be completed by a single person. It forms a high-precision control of "static measurement - quantitative adjustment - dynamic verification", which completely solves the technical problem of static compliance but dynamic roll movement and deviation.
[0035] (4) The method of the present invention can quickly complete the roll cross-judgment through daily inspection, and can predict and prevent accidents such as bearing overheating and burning, steel piling, and strip deviation in advance, which significantly reduces the equipment failure rate and extends the service life of bearings and equipment.
[0036] (5) This invention is applicable to cylindrical rolls and rolls with symmetrical curvature, covering the alignment and maintenance scenarios of work rolls and support rolls of various rolling mills such as hot rolling, cold rolling, strip, bar and wire. It can be directly applied to both new and old steel rolling production lines without the need for equipment modification, and has strong versatility and on-site adaptability. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0038] Figure 1 This is a schematic diagram of the first trans-pressure measurement of the present invention;
[0039] Figure 2 This is a side view of the present invention;
[0040] Figure 3 This is a schematic diagram of the second cross-pressure measurement and the hidden mill stand reference surface of the present invention;
[0041] Figure 4 This is a schematic diagram illustrating the geometric principle of roll crossing.
[0042] Figure 5 This is a schematic diagram illustrating the principle when the upper roll has a tendency to move radially forward and axially toward the drive side.
[0043] Figure 6 This is a schematic diagram illustrating the principle when the upper roll has a tendency to move radially backward and axially towards the operating side.
[0044] Among them, 1. Upper roll; 2. Lower roll; 3. Straight rod; 4. Bearing housing; 401. Upper bearing housing on the operating side of the upper roll; 402. Upper bearing housing on the drive side of the upper roll; 403. Lower bearing housing on the operating side of the lower roll; 404. Lower bearing housing on the drive side of the lower roll; 5. Mill stand; 6. Liner plate; 601. Bearing housing liner plate; 602. Stand liner plate; 7. Gasket. Detailed Implementation
[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0047] Reference Figure 1-6 In implementing this invention, a reference plane is first selected. Four coplanar reference points are pre-set on the mill stand 5, denoted as the first reference point A, the second reference point F, the third reference point B, and the fourth reference point E. These reference points are precision-machined to ensure coplanarity and, because they do not participate in any assembly process, will not wear out, thus forming a long-term stable and fixed reference plane. Before measurement, the operator should confirm that the surfaces of the reference points are clean and free of oil. The two rolls (upper roll 1 and lower roll 2) are respectively installed inside the mill stand 5 via bearing seats 4.
[0048] Specifically, the upper roll 1 is supported by an upper bearing housing 401 on the operating side and an upper bearing housing 402 on the drive side; the lower roll 2 is supported by a lower bearing housing 403 on the operating side and a lower bearing housing 404 on the drive side. Each bearing housing and mill stand is fixed with a liner 6. The liner fixed to the bearing housing is called the bearing housing liner 601, and the liner fixed to the mill stand 5 is called the stand liner 602. A shim 7 is provided between the two. Adjustment is made only by adjusting the thickness of the stand liner 602 on the mill stand 5, which is achieved by increasing or decreasing the thickness of the shim 7 between the stand liner 602 and the bearing housing liner 601.
[0049] Then, a visual static assessment is performed. A straight rod 3 with sufficient rigidity is used. This straight rod 3 can be magnetically attached to the surface of the rolls, for example, a magnetic straight rod 3 can be selected to ensure stable attachment to the roll surface during bridging. The length of the straight rod 3 should ensure that both ends can extend to the reference point position. During operation, the straight rod 3 is bridging the roll surfaces of the upper roll 1 and the lower roll 2 in two different diagonal directions. During bridging, the straight rod 3 must simultaneously contact the roll surfaces of the upper roll 1 and the lower roll 2, and the straight rod 3 should be naturally attached to the highest point of the outer circle of the roll body (i.e., the horizontal section where the diameter is located), and forced pressing is not allowed. The first bridging is along the first diagonal direction, that is, from the first reference point A to the second reference point F. At this time, one end of the straight rod 3 points to the first reference point A, and the other end points to the second reference point F. The second bridging is along the second diagonal direction, that is, from the third reference point B to the fourth reference point E. One end of the straight rod 3 points to the third reference point B, and the other end points to the fourth reference point E. After each sizing, the gap between the two end faces of the straight rod 3 and the corresponding reference points is measured using a feeler gauge. This yields four gap values: the gap at the first reference point A during the first sizing is recorded as the first gap value. (Right now Figure 4 The distance between Aa in the middle), and the gap at the second reference point F is denoted as the second gap value. (Right now Figure 4 The distance between Ff in the middle); during the second span compression, the gap at the third reference point B is recorded as the third gap value. (Right now Figure 4 The distance between Bd in the middle), the gap at the fourth reference point E is recorded as the fourth gap value. (Right now Figure 4 (The distance between Ee in the equation).
[0050] Next, the deviation and roller misalignment direction are determined. Based on the above four gap values, the first gap value is calculated. With the second gap value The sum and the third gap value With the fourth gap value The absolute value of the difference between the sums, i.e. If the absolute value of the difference is not greater than the preset threshold... If this is the case, it can be determined that the center lines of the upper and lower rolls are coplanar and the rolls are parallel, requiring no static correction. If the difference is large, it indicates that there is a crossover problem in the rolls. The larger the absolute value of the difference, the more serious the crossover is. The value range is 0.05mm to 0.10mm, and the specific value is determined based on the thickness of the available gasket 7 on site.
[0051] Then, rapid quantitative correction is performed. One-sided correction values are taken. During adjustment, only adjust the thickness of one set of diagonally opposite shims 7, leaving the other set unchanged. The specific operating rules are as follows:
[0052] like This indicates that the gap in the first diagonal direction is too large. At this point, you can choose one of the following two methods to adjust it:
[0053] (a) Reduce the thickness of the shim 7 in the first diagonal direction (corresponding to the shim 7 between the bearing housing 4 where points A and F are located and the rolling mill stand) by one. That is, reduce the size of the side gasket by 7;
[0054] (b) Alternatively, increase the thickness of the shims 7 in the second diagonal direction (the shims 7 between the bearing housing 4 and the mill stand 5 where points B and E are located). That is, add a smaller side pad 7.
[0055] like This indicates that the gap in the second diagonal direction is too large. At this point, one of the following two methods can be used for adjustment:
[0056] (a) Reduce the thickness of the shim 7 in the second diagonal direction (corresponding to the shim 7 between the bearing housing 4 where points B and E are located and the rolling mill stand) by one. ;
[0057] (b) Alternatively, increase the thickness of the shims 7 in the first diagonal direction (the shims 7 between the bearing housing 4 where points A and F are located and the rolling mill stand) by... .
[0058] Both methods can achieve the calibration purpose, and the choice can be made based on the convenience of the site during actual operation. The shims 7 used for adjustment can be prefabricated thin shims 7, with the thinnest specification being 0.02mm and the commonly used specification being 0.05mm. For more precise adjustments, shims 7 of different thicknesses can be stacked. The liner plate 6 is usually fixed to the mill stand 5 with countersunk bolts. The bolt heads are embedded in the liner plate 6 and do not protrude from its surface to ensure a flat working surface. After adjustment, tighten the bolts to the standard torque and re-measure the four gap values with a feeler gauge until... Static calibration is complete.
[0059] To eliminate minor residual crossovers caused by factors such as feeler gauge error, residual gap, and assembly deformation in static measurements, a secondary dynamic trajectory verification is also required.
[0060] First, adjust the vertical clearance. Release the axial limit to allow the upper roll 1 and lower roll 2 to move freely. For hot rolling, place the soft copper rod into the roll gap on the operating side and the drive side respectively. After pressing down the upper roll 1 and lower roll 2, measure the thickness difference between the two ends of the soft copper rod. Repeatedly adjust the vertical clearance until the thickness difference on both sides is equal. For cold rolling, apply a small amount of lubricant (such as industrial grease) to the center of the upper roll 1. Keep the axial limit in place and allow the upper roll 1 and lower roll 2 to rotate freely. Observe the expansion marks of the lubricant to both ends of the upper roll 1 and lower roll 2. When the expansion length is consistent and the thickness is uniform, it indicates that the vertical clearance on the operating side and the drive side is equal; otherwise, continue adjusting until the expansion is uniform.
[0061] After the vertical clearance adjustment is completed, axial movement is observed. First, the orientation rules are defined: with the operating side facing the mill as the reference, the left side of the upper roll 1 and the lower roll 2 is the front side, and the right side is the rear side. The rotation direction of the upper roll 1 is counterclockwise, and the rotation direction of the lower roll 2 is clockwise. The upper roll 1 is supported by the upper bearing seat 401 on the operating side and the upper bearing seat 402 on the drive side, and the lower roll 2 is supported by the lower bearing seat 403 on the operating side and the lower bearing seat 404 on the drive side.
[0062] Apply a lubricant indicator to the surface of the upper roll 1, release the axial restraint, and allow the upper roll 1 and lower roll 2 to idle without load. At this point, if the two rolls are perfectly parallel and there is no axial movement, the lubricant indicator will form a uniform circumferential mark on the roll surface. If there is slight overlap, the rolls will experience axial movement; the combined effect of rotational motion and axial movement will compress the lubricant indicator, forming a clear spiral line on the roll surface. The operator can directly observe the actual direction of the upper roll's movement.
[0063] Based on the observations, adjust shim 7 according to the following rules (this adjustment only addresses the slippage of the upper roll 1; the slippage of the lower roll 2 is indirectly eliminated through the adjustment of the upper roll 1):
[0064] Reference Figure 5 ( Figure 5 (The solid line represents the upper roll 1, and the dashed line represents the lower roll 2). If the rotation direction of the upper roll 1 causes it to tend to move radially forward and axially toward the transmission side, the shim 7 located on the front side between the upper bearing seat 401 on the operating side of the upper roll and the mill stand 5 should be increased, or the shim 7 located on the front side between the upper bearing seat 402 on the transmission side of the upper roll and the mill stand 5 should be decreased.
[0065] Reference Figure 6 ( Figure 6(The solid line represents the upper roll 1, and the dashed line represents the lower roll 2). If the rotation direction of the upper roll 1 causes it to tend to move radially backward and axially towards the operating side, reduce the shim 7 located on the front side between the upper bearing seat 401 on the operating side of the upper roll and the mill stand 5, or increase the shim 7 located on the front side between the upper bearing seat 402 on the drive side of the upper roll and the mill stand 5. It should be noted that: Figure 5 and Figure 6 For ease of understanding, the schematic diagram shows an enlarged representation of the radial movement of the rolls. In actual dynamic verification, operators observe axial movement (movement along the axis), not radial movement. The trend of radial movement is determined by the direction of rotation and does not require observation; simply adjust the front or rear shims based on the direction of rotation.
[0066] After each fine-tuning, repeat the steps of dotting, idling, and observing until there is no movement and no spiral lines on the roller surface.
[0067] Finally, verification and acceptance are conducted. After dynamic correction meets the standards, the limit structures of all anti-roll skew devices on the rolling mill are restored, and installation and fixing are completed according to standard requirements. The rolling mill is started for no-load operation to check for any abnormal roll skew and to confirm that there are no abnormal noises during bearing operation. Then, a strip rolling trial is performed to observe whether the strip running trajectory is aligned and whether there are any deviations or edge scraping phenomena. At the same time, the bearing temperature is monitored to confirm that the temperature is within the normal operating range. After no abnormalities are found during no-load operation and trial rolling, the roll axis parallelism correction is deemed complete, and the equipment can be put into normal production.
[0068] The following two specific examples further illustrate this point.
[0069] Example 1:
[0070] A hot rolling production line experienced a fault where the work rolls continuously deviated towards the drive side, the operating side rolls showed significant lateral movement towards the operating side, and the temperature of the drive side bearings continuously increased. The method of this invention was used to correct the fault after the line was shut down.
[0071] The operator first confirms the positions of four reference points A, F, B, and E on the archway. A straight rod 3, which can be magnetically secured, is then used. The first straddle press is performed along the first diagonal direction (A→F), with one end of the rod pointing towards A and the other towards F. The measurement is then taken using a feeler gauge. , The second transverse compression was measured along the second diagonal direction (B→E). , .calculate , Difference Preset threshold , =0.80mm> The determination indicates a serious overlap. Because... The gap in the second diagonal direction is relatively large. Unilateral correction amount. This embodiment reduces the size of the larger side shims 7: the shims 7 in the second diagonal direction (corresponding to the shims 7 between the bearing housing 4 and the rolling mill stand 5 where points B and E are located) are each reduced by 0.40mm, while the shims 7 in the first diagonal direction remain unchanged. The four gaps are then remeasured. , Static compliance.
[0072] Dynamic verification is then performed. After releasing the axial limit, the vertical clearance is first adjusted: the soft copper rod pressing method is usually used on hot rolling production lines. A section of soft copper rod is placed into the roller gap on the operating side and the drive side respectively. After pressing, it is taken out and the thickness difference between the two ends is measured. The pressing mechanism is adjusted so that the thickness difference between the two sides is less than 0.01mm. At this time, the vertical clearance between the operating side and the drive side is equal.
[0073] Then, apply grease (i.e., lubricant) to the upper roll 1 and let the upper roll 1 and lower roll 2 idle. Observe that the upper roll 1 slowly moves towards the operating side. According to the orientation rules, the upper roll 1 rotates counterclockwise. This movement belongs to "a tendency to move radially to the rear and axially towards the operating side". Therefore, reduce the shim 7 located on the front side between the upper bearing housing 401 on the operating side of the upper roll and the mill stand 5, or increase the shim 7 located on the front side between the upper bearing housing 402 on the drive side of the upper roll and the mill stand 5. Thus, reduce the thickness of the shim 7 located on the front side between the upper bearing housing 401 on the operating side of the upper roll and the mill stand 5 by 0.05mm (i.e., 50μm). After idle running again, there is no movement or spiral line. The limit is restored, and the test rolling is normal with no deviation. The bearing temperature is normal, and the fault is eliminated.
[0074] Example 2:
[0075] During routine inspections of a cold rolling production line, unilateral wear was observed on the work roll surface, and the operating side bearing temperature was slightly higher, raising suspicion of roll crossover. The method described in this invention was used for prediction and correction.
[0076] The operator first confirms the positions of four reference points A, F, B, and E on the archway. A straight rod 3, which can be magnetically secured, is then used. The first straddle press is performed along the first diagonal direction (A→F), with one end of the rod pointing towards A and the other towards F. The measurement is then taken using a feeler gauge. , The second transverse compression was measured along the second diagonal direction (B→E). , .calculate , Difference Preset threshold , =0.35mm> The result indicates an overlap. Because... The gap in the second diagonal direction is relatively large, and the single-sided correction amount is large. This embodiment uses the method of adding smaller side shims 7: the shims 7 in the first diagonal direction (the shims 7 between the bearing housing 4 where points A and F are located and the rolling mill stand 5) are each increased by 0.175mm, while the shims 7 in the second diagonal direction remain unchanged. The four gaps are then re-measured. , =0, static standard met.
[0077] During dynamic verification, the axial limit is released, and the vertical clearance is adjusted first. On cold rolling production lines, the method of observing grease spread is commonly used. The applied grease spreads towards both ends as the roll rotates. When the grease spreads to both ends with the same length, it indicates that the vertical clearance between the operating side and the drive side is equal. After confirming the vertical clearance is equal, grease is applied again and the roll is idled. A slight shift towards the drive side of the upper roll 1 is observed. According to the orientation rules, the upper roll 1 rotates counterclockwise. This shift is a "tendency to move radially forward and axially towards the drive side." Therefore, the shim 7 between the upper bearing seat 401 on the operating side of the upper roll and the mill stand 5 should be increased, or the shim 7 between the upper bearing seat 402 on the drive side of the upper roll and the mill stand 5 should be decreased. Thus, the thickness of the shim 7 between the upper bearing seat 401 on the operating side of the upper roll and the mill stand 5 is increased by 0.03 mm (i.e., 30 μm). After another idle run, the shift disappears, and the grease spreads evenly to both ends. The limit switch was restored, and there was no deviation during trial rolling. No further wear or roll shifting occurred during the subsequent month of production.
[0078] The above embodiments are merely specific applications of the present invention and are not exhaustive. In actual production, the preset threshold can be appropriately adjusted according to factors such as the rolling mill model, roll diameter, and bearing precision. The method of stacking with gasket 7. Any equivalent substitutions or improvements made based on the technical solution of this invention shall fall within the protection scope of this invention.
[0079] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A method for determining and correcting the parallelism of a roll axis, characterized in that: Includes the following steps: Step 1: Pre-set the first reference point, the second reference point, the third reference point and the fourth reference point on the mill stand (5). The four reference points are coplanar and form a fixed reference plane. Step 2: Using a straight rod (3), press it across the surfaces of the upper roll (1) and the lower roll (2) along the first diagonal direction and the second diagonal direction respectively. During the pressing, the straight rod (3) should simultaneously contact the surfaces of the upper roll (1) and the lower roll (2), wherein: When the rod is pressed across the first diagonal direction, the first end of the straight rod (3) points to the first reference point and the second end points to the second reference point; When the rod is pressed across the second diagonal direction, the first end of the straight rod (3) points to the third reference point and the second end points to the fourth reference point; Step 3: Measure the gap between the first end of the straight rod (3) and the first reference point and the gap between the second end and the second reference point during the first spanning test to obtain the first gap value and the second gap value; measure the gap between the first end of the straight rod and the third reference point and the gap between the second end and the fourth reference point during the second spanning test to obtain the third gap value and the fourth gap value. Step 4: Calculate the absolute value of the difference between the sum of the first gap value and the second gap value and the sum of the third gap value and the fourth gap value. When the absolute value of the difference is not greater than a preset threshold, determine that the center lines of the upper roll (1) and the lower roll (2) are coplanar. When the absolute value of the difference is greater than the preset threshold, adjust the thickness of one set of diagonal shims (7) so that the sum of the thickness adjustments of the set of shims (7) is equal to the absolute value of the difference. The other set of diagonal shims remains unchanged. Then remeasure the four gap values and calculate the absolute value of the difference until the absolute value of the adjusted difference is not greater than the preset threshold. The shims (7) are located between the bearing seat (4) used to support the upper roll (1) or the lower roll (2) and the mill stand (5).
2. The method for determining and correcting the parallelism of a roll axis according to claim 1, characterized in that: The absolute value of the difference in step four is ,in, , , , These are the first gap value, second gap value, third gap value, and fourth gap value obtained in step three, respectively; the preset threshold is... .
3. The method for determining and correcting the parallelism of a roll axis according to claim 2, characterized in that: The preset threshold The value range is 0.05mm to 0.10mm.
4. The method for determining and correcting the parallelism of a roll axis according to claim 2, characterized in that: The phrase "adjusting the thickness of only one set of diagonal shims (7)" refers to: when At that time, reduce the number of shims (7) in the first diagonal direction. Alternatively, add gaskets (7) to each of the second diagonal directions. ;when At that time, increase the number of shims (7) in the first diagonal direction. Or reduce the number of gaskets (7) in the second diagonal direction. ;in , .
5. The method for determining and correcting the parallelism of a roll axis according to claim 1, characterized in that: The straight rod (3) is connected to the upper roll (1) and the lower roll (2) by magnetic attraction.
6. The method for determining and correcting the parallelism of a roll axis according to claim 1, characterized in that: In step three, a feeler gauge is used to measure the gap.
7. The method for determining and correcting the parallelism of a roll axis according to claim 1, characterized in that: It also includes dynamic verification and acceptance steps: Step 5: After completing the adjustment of the shim (7) in step 4, first release the axial limit, and then adjust the vertical clearance so that the vertical clearance between the operating side and the transmission side is equal. Step 6: Apply lubricant indicator to the surface of the upper roll (1), and let the upper roll (1) and the lower roll (2) run without load. Observe the axial movement direction of the upper roll (1) and the lower roll (2) and whether a spiral line appears on the roll surface. When there is axial movement, the rotation of the upper roll (1) and the lower roll (2) will squeeze the lubricant indicator to form a spiral line on the roll surface. Step 7: When axial movement is observed, adjust the shims (7) according to the actual movement direction of the upper roll (1) and the predefined orientation rules. The orientation rules are as follows: with the operating side facing the mill as the reference, the left side of the upper roll (1) and the lower roll (2) is the front side, and the right side of the upper roll (1) and the lower roll (2) is the rear side. The rotation direction of the upper roll (1) is counterclockwise, and the rotation direction of the lower roll (2) is clockwise. The upper roll (1) is supported by the upper bearing seat (401) on the operating side of the upper roll and the upper bearing seat (402) on the drive side of the upper roll. The lower roll (2) is supported by the lower bearing seat (403) on the operating side of the lower roll and the lower bearing seat (404) on the drive side of the lower roll. If the rotation direction of the upper roll (1) causes the upper roll (1) to have a tendency to move radially forward and axially toward the transmission side, the shim (7) located on the front side between the upper bearing seat (401) on the operating side of the upper roll and the mill stand (5) is increased, or the shim (7) located on the front side between the upper bearing seat (402) on the transmission side of the upper roll and the mill stand (5) is decreased. If the rotation direction of the upper roll (1) causes the upper roll (1) to have a tendency to move radially to the rear and axially to the operating side, reduce the shim (7) located on the front side between the upper bearing seat (401) on the operating side of the upper roll and the mill stand (5), or increase the shim (7) located on the front side between the upper bearing seat (402) on the drive side of the upper roll and the mill stand (5). Repeat steps six and seven until there is no more movement and no spiral lines; Step 8: Restore the axial limit, allow the upper roll (1) and the lower roll (2) to run idle, confirm that there is no roll slippage or abnormal noise, and perform strip rolling test to confirm that the strip does not deviate.
8. The method for determining and correcting the parallelism of a roll axis according to claim 7, characterized in that: The method for adjusting the vertical gap in step five is as follows: For hot rolling, the soft copper rod is placed into the roller gap on the operating side and the transmission side respectively. After pressing down the upper roller (1) and the lower roller (2), the thickness difference between the two ends of the soft copper rod is measured, and the vertical gap is adjusted until the thickness difference on both sides is equal. For cold rolling, apply a lubricant indicator to the middle of the roll surface of the upper roll (1), keep the axial limit so that the upper roll (1) and lower roll (2) can rotate freely, and observe the expansion marks of the lubricant indicator to both ends of the upper roll (1) and lower roll (2). When the expansion length is consistent and the thickness is uniform, it is determined that the vertical gap is equal; otherwise, continue to adjust until the expansion is uniform.