A method for predicting thermal deformation and pre-offset compensation of a scrap shears transmission system based on thermal-structural coupling

Abstract

The application discloses a kind of based on heat-structure coupling's scrap edge shear transmission system thermal deformation prediction and pre-offset compensation method, belong to metallurgical cold rolled strip finishing processing equipment and its precision control technical field.For the asymmetric heating and side gap drift under different shearing line speed, gear meshing friction, bearing friction and oil pool oil stirring heat source are quantified respectively;With asymmetric convection heat transfer boundary, steady-state heat conduction and statics sequential coupling are carried out, and the differential thermal elongation of upper and lower knife shafts and the change of side gap are extracted;The discrete working condition data is fitted by polynomial least square, and the continuous mapping of line speed and side gap change is established;According to the target line speed, the thermal state change is predicted, the pre-offset is calculated and executed in the cold state idle stage, and the positioning is locked.This method is used for the scrap edge shear side gap compensation corresponding to the thermal steady state condition of different target line speed.

Description

Technical Field

[0001] This invention relates to the field of finishing equipment for cold-rolled strip metallurgy and its precision control technology, specifically to a method for predicting thermal deformation and pre-offset compensation of a shear transmission system for edge trimming based on thermal-structural coupling. Background Technology

[0002] Edge trimming shears are used to cut continuous long strips of waste edges removed on the strip finishing production line, and are usually located downstream of the disc shear. The side clearance between the upper and lower blades affects the shearing state of the waste edges. When processing thin strip waste edges with high brittleness, deviations in the side clearance from the process setting may cause problems such as incomplete shearing of the waste edges. Therefore, it is necessary to adapt the blade setting position to the actual working conditions.

[0003] Chinese invention patent application CN103264190A, entitled "A Side Clearance Adjustment Mechanism for Edge Trimming Shears," was published on August 28, 2013. This document describes a mechanism that adjusts the axial displacement of the upper cutter shaft by adjusting a motor-driven threaded pair, and then uses displacement detection and the angle relationship between the blade and gear to achieve side clearance adjustment. While this solution provides a mechanical adjustment and positioning basis, its disclosure primarily focuses on the adjustment mechanism and the geometric relationship between the axial displacement and the blade side clearance.

[0004] The aforementioned document does not describe the technical process of quantifying gear meshing friction, bearing friction, and oil slick dissipation corresponding to different shear linear velocities, then combining this with asymmetric heat transfer conditions to solve for differential thermal elongation, and finally calculating the cold-state pre-bias amount. Therefore, based solely on the geometric adjustment relationship described in the document, it is not possible to determine the amount of thermal deformation compensation that changes with the target shear linear velocity. This deficiency pertains to the disclosed thermal compensation information and does not negate its mechanical adjustment function.

[0005] For edge shears using a bottom-mounted oil bath lubrication system, the heat generation location, heat transfer coefficient, and surrounding medium temperature differ between the oil-immersed and air-exposed parts. Gear meshing losses, bearing friction at different supports, and lower oil churning dissipation collectively form a spatially asymmetric heat source, potentially causing inconsistent thermal displacements between the upper and lower cutter shafts, thus altering the side clearance. Under approximate conditions of lubrication and correlation coefficients, oil churning dissipation varies cubically with angular velocity, while bearing friction power varies with both rotational speed and friction torque. Therefore, a fixed bias independent of the operating conditions cannot cover the entire target speed.

[0006] Furthermore, some edge shear clearance adjustment mechanisms are locked during loaded shearing, making online fine-tuning unsuitable. For such equipment, the clearance should be pre-determined in the cold, unloaded phase, matching the subsequent stable operating conditions, rather than forcibly adjusting under load after thermal deformation occurs. Summary of the Invention

[0007] To address the aforementioned problems, the present invention aims to provide a method for predicting and pre-offsetting the thermal deformation of a shear transmission system based on thermal-structural coupling. This method enables the cold-state blade setting position to compensate for the predicted changes in the hot-state side clearance under the target operating conditions, and adapts to equipment conditions where side clearance adjustment is not advisable during loading. This achieves precise control and high stability of the shear side clearance under different shearing linear speeds.

[0008] The technical solution of this invention is: a method for predicting thermal deformation and pre-biasing compensation of a scrap edge shear transmission system based on thermal-structural coupling, comprising the following steps: Step 1: Dynamic Quantization Modeling of Asymmetric Heat Sources with Different Shear Linear Velocities: The operating parameters of the edge trimmer under different shearing linear velocities are extracted, and the power of gear meshing frictional heat generation, bearing frictional heat generation, and oil sump churning dissipation power as the shearing linear velocity changes are quantitatively calculated. A dynamic mapping relationship between the input shearing linear velocity and the asymmetric heat generation rate is established. The operating parameters include the equipment transmission relationship, cutting load, representative cutting torque, and gear efficiency. Step 2: Discrete operating condition thermo-structural coupling and differential thermal elongation extraction: Several discrete typical linear velocity operating conditions are selected, and corresponding heat-generating loads and asymmetric convective heat transfer boundaries are applied in the finite element model respectively. Through steady-state heat conduction and static sequential coupling analysis, the differential thermal elongation of the upper and lower cutter shafts caused by the asymmetric thermal expansion of the frame under each shear linear velocity condition is extracted, and the resulting change in side clearance is calculated. Step 3: Construct a continuous response surface function for the change in shear line velocity and side clearance on the production line: Based on the least squares method of polynomial regression analysis, a continuous analytical mapping function is constructed with the production line shear line velocity as the independent variable and the change in side clearance as the dependent variable. Step 4: Implementation of compensation strategies for different working conditions: Using the continuous analytical mapping function as the prediction basis, for different target shearing line speeds on the production line, the corresponding side clearance adjustment amount is predicted according to the continuous analytical mapping function, and the upper cutter shaft side clearance adjustment servo mechanism is driven to adjust it, so as to achieve the stability of the side clearance under different shearing line speed conditions.

[0009] Further, in step 1, the heat generation power of the gear meshing friction is calculated based on the cutting torque and transmission efficiency at the corresponding shear line velocity, and the steady-state heat generation power of the gear on one side is determined according to the heat distribution relationship of the gear meshing area; the steady-state heat generation power of the gear on one side is divided by the corresponding equivalent heat generation ring volume in the finite element model to obtain the volumetric heat source load applied to the gear meshing area.

[0010] Furthermore, in step 1, the structural dimension parameters and dynamic equivalent force parameters of the front main bearing and the rear adjustable bearing are extracted respectively, and the friction torque and frictional heat generation power of the two types of bearings are calculated respectively. The frictional heat generation power of each bearing is divided by its corresponding equivalent heat generation volume and applied to the corresponding bearing area in the finite element model to form a differentiated spatial heat source for the multi-support shaft system.

[0011] Further, in step 1, based on the oil-immersed structure of the lower gearbox, the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient are extracted. The shear linear velocity is converted into the corresponding angular velocity. An oil pool churning dissipation model is established that is proportional to the cube of the angular velocity when the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient remain unchanged. The calculated oil pool churning dissipation power is equivalent to an additional volumetric heat source and superimposed on the lower cutter shaft area.

[0012] Furthermore, in step 2, in the three-dimensional finite element model, based on the immersion lubrication structure of the lower part of the gearbox and the lower cutter shaft, the lower half oil immersion zone is set as the oil convection heat transfer boundary, and the upper half air zone is set as the air natural convection heat transfer boundary. The heat transfer coefficient of the oil convection heat transfer boundary is greater than the heat transfer coefficient of the air natural convection heat transfer boundary, and the medium temperature corresponding to the two types of boundaries is set respectively.

[0013] Furthermore, in step 2, the temperature field obtained from the steady-state heat conduction analysis is imported into the static analysis as a temperature load, and a fixed constraint boundary is set at the bottom of the frame; the displacement of the characteristic node at the front end of the upper cutter shaft and the displacement of the characteristic node at the front end of the lower cutter shaft are extracted respectively in the same side clearance measurement direction, and the absolute value of the difference between the two is used as the differential thermal elongation, and the magnitude of the side clearance change and the direction of its increase or decrease are determined according to the relative position of the corresponding blades.

[0014] Furthermore, in step 3, using the side clearance changes corresponding to multiple different shear linear velocity conditions as discrete samples, a third-order polynomial regression is performed using the least squares method. The continuous analytical mapping function is:

[0015] in, The shear line velocity, This represents the predicted change in side clearance at the corresponding shear linear velocity. , , and The regression coefficients are determined from the discrete samples.

[0016] Furthermore, in step 4, the target shear linear velocity is obtained. and the ideal working side clearance required by the process The change in side clearance under the target shear linear velocity is calculated based on the continuous analytical mapping function. The static pre-bias command value is calculated according to the following formula:

[0017] in, The side clearance that needs to be set during the cold tool setting stage. The increase in side clearance is positive and the decrease in side clearance is negative; the static pre-bias instruction value is sent to the programmable logic controller, which drives the upper tool axis side clearance adjustment servo mechanism to perform physical positioning compensation.

[0018] Furthermore, the physical positioning compensation is performed during the tool setting stage when the equipment is in a cold state, and the equipment is stopped or in an unloaded and non-biting state during the execution. The upper blade is positioned to the position corresponding to the static pre-bias command value by the upper blade shaft side clearance adjustment servo mechanism. When the predicted side clearance change is positive, the initial unloaded side clearance is set to be smaller than the ideal working side clearance, so as to offset the increase in hot side clearance under the target shearing linear velocity with the pre-set negative deviation.

[0019] Furthermore, after the physical positioning compensation is completed, the upper tool axis side clearance adjustment servo mechanism is locked, and the positioning state is maintained during subsequent load shearing without online fine-tuning; when subsequent production tasks use different target shearing linear speeds, after the conditions of the cold tool setting stage are met again, the corresponding static pre-offset command value is recalculated and positioning compensation is performed.

[0020] The beneficial effects of this invention are: By quantifying gear meshing friction, front and rear bearing friction, and oil slick dissipation separately and applying them to the corresponding spatial regions, the position and variation patterns of various heat sources can be preserved in the model. Combined with the different convective heat transfer boundaries of the oil immersion zone and the air zone, a description of heat input and heat dissipation corresponding to the equipment lubrication arrangement is formed, avoiding the simple equivalent of the entire transmission system to a uniform temperature rise body.

[0021] By extracting the thermal displacement of the front ends of the upper and lower cutter shafts and the relative displacement of the corresponding blades in the same measurement direction, the side clearance change is determined by the differential amount rather than the absolute thermal displacement of any cutter shaft. This can distinguish between common thermal elongation and relative thermal elongation that truly changes the shearing side clearance, reducing errors in compensation calculation caused by confusion of measurement direction or displacement object.

[0022] By performing least-squares polynomial regression on the side clearance changes under multiple discrete working conditions, the thermo-structural model that needs to be solved offline is transformed into a continuous function that can be calculated in the controller. Within the applicable conditions of the model and the verified speed range, corresponding compensation amounts can be generated for different target linear velocities, without having to re-execute the complete finite element solution every time the tool is set.

[0023] The cold-state pre-offset is calculated by subtracting the predicted thermal change from the ideal working side clearance. Servo positioning and locking are completed during shutdown or no-load non-sticking phases. Subsequent thermal deformation can offset the pre-set reverse deviation, without requiring online fine-tuning during loading. This effect applies to the stable thermal state corresponding to the target speed and is not equivalent to ensuring that the side clearance remains unchanged during any speed increase, decrease, or coil change thermal transition process.

[0024] By converting the predicted side clearance value into the actual positioning command of the adjustment mechanism and retaining the direction of side clearance increase or decrease, the calculation result is ultimately applied to the physical position of the cutter shaft and the blade, forming a technical control process oriented towards the processing accuracy of edge trimming, rather than just outputting a mathematical fitting curve. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the overall process of the method of the present invention.

[0026] Figure 2 The curve for calculating the frictional heat generation power of the bearing.

[0027] Figure 3 The trend chart of normalized power dissipation for oil slurry in the oil bath.

[0028] Figure 4 This is a graph showing the correspondence between a given discrete side gap change and a third-order least squares fitted curve.

[0029] Figure 5 This is a schematic diagram showing the target of edge trimming and the pre-bias control relationship.

[0030] Figure 6 The execution flowchart for cold pre-bias positioning and load locking.

[0031] Reference numerals in the attached diagram: 1. Frame; 2. Gearbox; 3. Upper cutter shaft; 4. Lower cutter shaft; 5. Upper blade; 6. Lower blade; 7. Front main bearing; 8. Rear clearance adjusting bearing; 9. Upper gear; 10. Lower gear; 11. Oil sump; 12. Upper cutter shaft side clearance adjustment servo mechanism; 13. Programmable logic controller. Detailed Implementation

[0032] The embodiments of the present invention are described below with reference to the accompanying drawings. The side clearance is the lateral distance between corresponding reference surfaces of the two blades under a specified shear phase; the "dynamic mapping relationship" represents the correspondence between the heat source and the linear velocity operating condition, and does not describe steady-state thermal analysis as a transient solution to the temperature distribution at any given time. The heat source parameters, structural parameters, and model boundaries in each embodiment should be consistent with the actual equipment and selected operating conditions.

[0033] Example 1: This embodiment combines Figure 1 The overall method of the present invention will be described. For example... Figure 5 As shown, the tool shaft includes an upper tool shaft 3 and a lower tool shaft 4. Figure 1 As shown, the present invention provides a method for predicting thermal deformation and pre-biasing compensation of a shear transmission system based on thermal-structural coupling, comprising the following steps: Step 1: Dynamic Quantization Modeling of Asymmetric Heat Sources with Different Shear Linear Velocities: The operating parameters of the edge shear under different shearing linear velocities are extracted, and the power of gear meshing frictional heat generation, bearing frictional heat generation, and oil swirl dissipation power in the oil bath 11 as the shearing linear velocity changes are quantitatively calculated. A dynamic mapping relationship between the input shearing linear velocity and the asymmetric heat generation rate is established. The operating parameters include the equipment transmission relationship, cutting load, representative cutting torque, and gear efficiency. Step 2: Discrete operating condition thermo-structural coupling and differential thermal elongation extraction: Several discrete typical linear velocity operating conditions are selected, and corresponding heat-generating loads and asymmetric convective heat transfer boundaries are applied in the finite element model respectively. Through steady-state heat conduction and static sequential coupling analysis, the differential thermal elongation of the upper cutter shaft 3 and lower cutter shaft 4 caused by the asymmetric thermal expansion of the frame 1 under each shear linear velocity condition is extracted, and the resulting change in side clearance is calculated. Step 3: Construct a continuous response surface function for the change in shear line velocity and side clearance on the production line: Based on the least squares method of polynomial regression analysis, a continuous analytical mapping function is constructed with the production line shear line velocity as the independent variable and the change in side clearance as the dependent variable. Step 4: Implementation of compensation strategies for different working conditions: Using the continuous analytical mapping function as the prediction basis, for different target shearing line speeds on the production line, the corresponding side clearance adjustment amount is predicted according to the continuous analytical mapping function, and the upper cutter shaft side clearance adjustment servo mechanism 12 is driven to adjust it, so as to achieve the stability of the side clearance under different shearing line speed conditions.

[0034] Steps 1 to 3 are performed during the offline modeling and calibration phase: first, three categories of heat sources are determined according to the target speed; then, the thermal displacement is solved for each discrete working condition; finally, a continuous function that the controller can call is formed. Step 4 uses the predicted values ​​for the actual positioning of the upper tool shaft side clearance adjustment servo mechanism 12, not only saving or displaying the predicted curve. Asymmetric heat sources refer to heat sources whose location, power, or distribution differs between the upper and lower parts; it is not simply changing the name of the same uniform heat source.

[0035] For equipment where side clearance cannot be adjusted during loading, step 4 adopts the cold-state pre-biasing method described in Example 4: During the cold-state no-load phase, a reverse bias is determined, adjustment is performed, and the bias is kept locked, so that the thermal changes corresponding to the target speed cancel out the pre-set bias. Here, the operating condition stability is maintained at a stable thermal state for the corresponding target speed, and the transient thermal analysis is not replaced by real-time recalculation of the steady-state function during acceleration and deceleration.

[0036] Example 2: This embodiment is based on the method of Embodiment 1, combined with Figure 2 , Figure 3 and Figure 5 Explain the heat source model, boundary input, and the extraction method of differential thermal elongation. Figure 5 This is a schematic diagram of the relationship between components and functions. Solid lines represent transmission, support, or control relationships. It is not drawn to scale and does not limit the number of bearings, the number of gear teeth, or the specific form of servo transmission pairs.

[0037] The frame 1 supports the gearbox 2 and the cutter shaft support. The upper cutter shaft 3 is equipped with the upper blade 5 and is driven by the upper gear 9; the lower cutter shaft 4 is equipped with the lower blade 6 and is driven by the lower gear 10. The front main load bearing 7 is located in a support position close to the shearing operation side, and the rear adjustable bearing 8 is located in the rear positioning and adjustable support position. Figure 5 The front main bearing 7 and the rear adjustable bearing 8 in the model represent the corresponding types of supports. In actual modeling, they are established separately according to the actual assembly position. The two types of supports cannot be merged into the same equivalent heat point.

[0038] The oil sump 11 is located at the lower part of the gearbox 2, forming an oil-immersed area around the lower transmission part, while the upper un-oil-immersed part constitutes an air zone. The programmable logic controller 13 sends control commands to the upper tool shaft side clearance adjustment servo mechanism 12, which performs axial adjustment to change the position of the upper blade 5 relative to the lower blade 6. Figure 5 The “control command” and “axial adjustment” shown represent control signal transmission and physical adjustment, respectively, rather than heat source input.

[0039] I. Operating Parameters and Unit Conventions With shear line velocity As operating condition variables, This indicates the pitch circle radius of the cutter head used for linear velocity conversion. Velocity Using meters per minute (m / min), radius Convert to meters (m) in the calculation; angular velocity Using radians per second (rad / s), rotational speed Use revolutions per minute (r / min). When the input linear velocity equals the circumferential linear velocity at the pitch circle, the conversion relationship is: (1) In the formula, π is the mathematical constant, and 60 is the conversion factor between minutes and seconds. This calculation example uses... Millimeter (mm), which is 0.302 meters; when At a speed of meters per minute, the angular velocity is approximately 19.315673 radians per second. If there is a predetermined transmission ratio or lead ratio between the production line linear velocity and the cutter head circumferential linear velocity, the conversion should be performed according to the equipment relationship first, and the same speed definition should be used during modeling and controller invocation.

[0040] Except for displacements, side clearances, and geometric examples explicitly expressed in millimeters, heat source calculations use the International System of Units (SI): force in Newtons (N), torque in Newton-meters (N·m), power in watts (W), volume in cubic meters (m³), and volumetric heat sources in watts per cubic meter (W / m³). Torque calculated in millimeters must not be directly substituted into power formulas using Newton-meters, nor must velocity in meters per minute be directly used as meters per second.

[0041] II. Heat generation and load equivalent of gear meshing friction In step 1, the heat generation power of the gear meshing friction is calculated based on the cutting torque and transmission efficiency at the corresponding shear line velocity, and the steady-state heat generation power of the gear on one side is determined according to the heat distribution relationship of the gear meshing area; the steady-state heat generation power of the gear on one side is divided by the corresponding equivalent heat generation ring volume in the finite element model to obtain the volumetric heat source load applied to the gear meshing area.

[0042] For each target speed, the equipment transmission relationship, cutting load, representative cutting torque, and gear efficiency are read. For periodic shearing, the representative load is converted into the periodic average heat power according to the corresponding duty cycle; if the periodic average input power has already been obtained, it is not multiplied by the duty cycle again. The heat power calculation and volumetric heat source conversion of a single-sided gear can be written as: (2) In the formula, For the first Average heat generation power of the side gear This is the heat distribution coefficient on this side, and the sum of the distribution coefficients on both sides is 1; For load duration, This represents the representative input torque at the corresponding transmission position. The angular velocity at that position. For the corresponding transmission efficiency; The equivalent heating ring volume allocated to this side of the heat source, This is the corresponding volumetric heat source. The above operating parameters can be adjusted accordingly. Variations should not be assumed to mean that losses are the same at all speeds simply because the rated motor power is used. The efficiency valued corresponds to the allocated gear meshing losses; if the total efficiency including bearing or oil churning losses is used, the separately accounted loss components should be excluded to avoid double counting of heat.

[0043] In one load conversion example, using an equivalent input power of 55 kW, a load duty cycle of 0.4, a gear efficiency of 0.98, and a distribution factor of 0.5 on each side, the average heat generation power on one side is calculated to be 220 W. This example is used to illustrate the heat load conversion under given power conditions; other operating conditions should use their corresponding actual input power or torque.

[0044] (3) In the formula, Let represent the equivalent volume of the heating ring on one side in this example; the outer radius of the ring is 0.151 meters, the inner radius is 0.13525 meters, and the axial width is 0.120 meters. Dividing 220 watts by this volume yields approximately [value missing] of the volumetric heat source. Watts per cubic meter, equivalent to 0.129439 milliwatts per cubic millimeter (mW / mm³). In the finite element model, this load is applied to the gear meshing equivalent region that corresponds to the belt volume.

[0045] III. Calculation of Differences in Frictional Heat Generation Between Front and Rear Bearings In step 1, the structural dimension parameters and dynamic equivalent force parameters of the front main bearing 7 and the rear adjustable bearing 8 are extracted respectively, and the friction torque and frictional heat generation power of the two types of bearings are calculated respectively. The frictional heat generation power of each bearing is divided by its corresponding equivalent heat generation volume and applied to the corresponding bearing area in the finite element model to form a differentiated spatial heat source for the multi-support shaft system.

[0046] The outer diameter, inner diameter, effective width, and dynamic equivalent force parameters of the front main bearing 7 and the rear adjusting bearing 8 are collected separately. For actual bearings of the same type but with different positions or loads, separate parameter entries should also be established. Using a comprehensive friction coefficient adapted to the bearing type, lubrication condition, and load range, the equivalent friction torque is calculated using an approximate formula. (4) (5) In the formula, For bearing position index; , and These are the outer diameter, inner diameter, and effective width, respectively. The average diameter; This is the equivalent volume of the heating solid ring; The comprehensive friction coefficient; For dynamic equivalent force; , and These are respectively frictional torque, frictional heating power, and volumetric heat source; The angular velocity of the cutter shaft where the bearing is located. The outer diameter, inner diameter, and width are all expressed in meters when substituted into equations (4) and (5).

[0047] This example uses the front main bearing 7 with an outer diameter of 210 mm, an inner diameter of 150 mm, an effective width of 60 mm, and an equivalent force of 3000 N, and the rear adjustable bearing 8 with an outer diameter of 150 mm, an inner diameter of 100 mm, an effective width of 32.5 mm, and an equivalent force of 2000 N; the comprehensive friction coefficient of both types of bearings is taken as 0.002. The equivalent volumes recalculated according to the annular geometry are approximately 1017876 cubic millimeters and 319068 cubic millimeters, respectively, corresponding to frictional torques of 0.54 N·m and 0.25 N·m, respectively.

[0048] Under the conversion conditions of 350 m / min and a radius of 0.302 m, the frictional heat generation power of the two types of bearings mentioned above is approximately 10.430464 W and 4.828918 W, respectively. Figure 2 The "bearing friction heat generation power" curve is calculated according to the listed parameters and equations (1), (4), and (5). The two curves, "front-end main bearing 7" and "rear-end adjustable bearing 8", represent their respective power and do not mean that they have the same heat generation volume. Figure 2 The horizontal axis is labeled "shear linear velocity (m / min)" and the vertical axis is labeled "power (watts)". The power is then divided by the equivalent volume of the bearing to obtain the finite element load.

[0049] The coefficients above are approximations used to illustrate the calculation relationship from load to thermal power, and are not considered a complete bearing friction model that includes sealing, rolling, sliding, and all viscous losses. When the actual lubrication, load, or sealing conditions of a bearing differ from the approximate conditions, the manufacturer's applicable friction model or the effective friction torque calibrated by testing should be used, and each bearing should be calculated and loaded separately.

[0050] IV. Oil Dissipation in Oil Tank and its Equivalent Region In step 1, based on the oil-immersed structure of the lower part of the gearbox 2, the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient are extracted. The shear linear velocity is converted into the corresponding angular velocity. An oil churning dissipation model of the oil pool 11 is established that is proportional to the cube of the angular velocity when the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient remain unchanged. The calculated oil churning dissipation power of the oil pool 11 is equivalent to an additional volumetric heat source and superimposed on the region of the lower cutter shaft 4.

[0051] Based on the immersion radius and immersion depth of the lower gear 10, the lubricating oil density corresponding to the type of oil used and the temperature is read to determine the immersion depth coefficient and resistance coefficient. The following equivalent oil churning dissipation model is adopted: (6) In the formula, The power dissipation of oil in oil tank 11 during stirring; This refers to the density of the oil, expressed in kilograms per cubic meter (kg / m³). The angular velocity of the oil-immersed gear; The radius of the lower gear's oil stirring mechanism; and These are the dimensionless immersion depth coefficient and drag coefficient, respectively; The volume required to accommodate this equivalent power dissipation; This is to provide a corresponding additional volumetric heat source. The coefficient is determined by the oil immersion geometry of the gears used, the applicable loss relationship, or the no-load loss calibration at the same oil level. The original coefficient cannot be directly used after the oil level or oil condition changes.

[0052] An equivalent geometric example uses Meters, equivalent axial length 0.120 meters, at this time cubic meters. This volume differs from the volume of the gear meshing heating ring in formula (3), and the two are not interchangeable. An additional heat source is applied to the equivalent region where the lower cutter shaft 4 is located; if distributed across multiple unit sets, the sum of the heat source integrals of each set should equal the sum of the integrals of the heat sources in each set. Instead of repeatedly applying the full stirring power to each set.

[0053] exist , , , And when the conversion relationship between linear velocity and angular velocity remains unchanged, a reference velocity is selected. meters per minute, from which the normalization relation can be obtained: (7) Figure 3 The "normalized power of oil dissipation in oil tank 11" and "power normalized to 1 under 350 m / min conditions" only represent the relative change trend of equation (7), and do not represent the actual wattage when the oil density and loss coefficient are not given, nor can they be used to deduce the uncalibrated absolute thermal power. Figure 3 The horizontal axis is labeled "shear linear velocity (m / min)," and the vertical axis is labeled "normalized power." The bearing thermal power and the churning oil thermal power must be calculated separately according to actual parameters before being included in the thermal analysis.

[0054] V. Finite Element Input and Asymmetric Heat Transfer Boundary In step 2, in the three-dimensional finite element model, based on the immersion lubrication structure of the lower part of the gearbox 2 and the lower cutter shaft 4, the lower half oil immersion zone is set as the oil convection heat transfer boundary, and the upper half air zone is set as the air natural convection heat transfer boundary. The heat transfer coefficient of the oil convection heat transfer boundary is greater than that of the air natural convection heat transfer boundary, and the medium temperature corresponding to the two types of boundaries is set respectively.

[0055] Based on the actual assembly drawings, a three-dimensional finite element model is established, including frame 1, gearbox 2, upper cutter shaft 3, lower cutter shaft 4, upper side gear 9, lower side gear 10, and corresponding support parts. To extract the side clearance, the geometric positional relationship between the front end of the cutter shaft and the reference surface of the blade involved in shearing should be preserved; small chamfers that do not affect the main heat transfer and support stiffness can be simplified, but differences between the upper and lower structures, bearing positions, or oil immersion heights cannot be eliminated.

[0056] Input the thermal conductivity, elastic modulus, Poisson's ratio, and coefficient of linear expansion for each entity, and establish the thermal conductivity and displacement transfer relationships at the assembly contact surfaces. These parameters are determined based on the actual material grade, assembly connection, and temperature range, and can be derived from material certification documents, equipment design data, or calibration results specific to the actual structure. The uniform reference temperature during cold-set tooling is used as the reference temperature for structural thermal strain, and is not replaced by the undefined zero degree Celsius.

[0057] In the oil immersion zone, the oil convection heat transfer coefficient and the oil temperature matched to the operating condition are set respectively; in the air zone, the air natural convection heat transfer coefficient and the ambient air temperature are set respectively. In this embodiment, under the applicable structure and lubrication conditions, the oil convection heat transfer coefficient is set to be greater than the air natural convection heat transfer coefficient. The temperature field is still obtained by combining the spatial heat source, the medium temperature, and the heat transfer conditions. It cannot be directly concluded that under any operating condition, the bottom is necessarily hot and the top is cold, based solely on the magnitude of the two heat transfer coefficients.

[0058] (8) In the formula, The solid temperature; Thermal conductivity; For the volumetric heat sources already allocated to each entity; The unit vector normal to the boundary; The convective heat transfer coefficient at the corresponding boundary; The temperature of the medium at this boundary; The gradient operator is represented by a dot product, indicating divergence or normal projection. Oil boundary parameters are used for the oil-immersed region, and air boundary parameters are used for the air region. Temperature difference is expressed in Kelvin (K) or an equivalent Celsius temperature difference; heat transfer coefficient is measured in watts per square meter (W / K), and thermal conductivity is measured in watts per meter (W / K).

[0059] For each discrete velocity condition, the heat sources from gear meshing, each bearing, and the additional heat source from oil sump 11 are all applied to the corresponding region, and the steady-state temperature field is solved. For the same condition, the consistency between the heat source integral and the corresponding power is checked, and the balance between the total heat input to the model and the steady-state heat dissipated through the boundary is checked to verify the volume units and repeated loading.

[0060] The steady-state temperature field is mapped to the structural model through shared nodes or coordinate interpolation, maintaining consistency in assembly position, material partitioning, and temperature reference. The bottom of frame 1 is fixedly constrained; the allowable degrees of freedom and locked clearance adjustment degrees of freedom of each bearing support are set according to the actual working state, which avoids rigid body drift and also avoids incorrectly constraining the allowable axial thermal elongation.

[0061] (9) In the formula, For stress tensor, Let be the elastic stiffness tensor determined by the elastic modulus and Poisson's ratio. For the total strain tensor, The coefficient of linear expansion is 1 / 3. This is the cold reference temperature. The value is a second-order unit tensor, and the colon indicates tensor contraction. Thermal displacement is solved by combining static equilibrium and the aforementioned support constraints. This embodiment extracts the displacement caused solely by temperature rise; if shear load is retained, the cold and hot models should use the same mechanical load, and the difference should be used to obtain the thermal increment, avoiding mistaking cutting elastic deflection for thermal deformation.

[0062] VI. Differential thermal elongation and directional lateral gap change In step 2, the temperature field obtained from the steady-state heat conduction analysis is imported into the static analysis as a temperature load, and a fixed constraint boundary is set at the bottom of the frame 1. The displacement of the characteristic node at the front end of the upper cutter shaft 3 and the displacement of the characteristic node at the front end of the lower cutter shaft 4 are extracted respectively in the same side clearance measurement direction. The absolute value of the difference between the two is used as the differential thermal elongation, and the magnitude of the side clearance change and the direction of its increase or decrease are determined according to the relative position of the corresponding blades.

[0063] The side clearance measurement direction is defined as the X-axis, with the positive X-direction taken as the direction of side clearance increase from the reference surface of the lower blade 6 to the reference surface of the upper blade 5 under a specified shear phase. In the same reference coordinate system and at the same shear phase, the thermal displacement of the corresponding feature nodes at the front ends of the upper blade axis 3 and the lower blade axis 4 along this direction is extracted to avoid subtracting the magnitudes of components or displacement vectors in different directions.

[0064] (10) In the formula, , The thermal displacement of the corresponding feature nodes at the front ends of the upper and lower tool shafts 3 and 4 in the side clearance measurement direction; This indicates the magnitude of differential thermal elongation. Index for discrete operating conditions; For the first The directional clearance variation under each operating condition. The absolute value of the differential cannot determine the compensation direction on its own; the pre-offset calculation should use the direction-preserving method. .

[0065] When the selected feature node can represent the axial thermal displacement of the corresponding blade reference surface, equation (10) can be directly used. When the blade tilt, local rotation angle, or rigidity of the front end to the cutting edge cannot be ignored, the displacement should be transferred to the corresponding cutting edge reference point, and the normal distance before and after thermal deformation should be compared; the displacement difference between any two shaft end nodes should not be unconditionally considered as the actual shear clearance change. The geometric calculation relationship is as follows: (11) In the formula, The unit vector representing the direction of increase in the selected side clearance; and The first Each working condition is mapped to the thermal displacement vector of the corresponding reference point of the upper blade 5 and the lower blade 6. When using shaft end nodes, the modeling assumption that the displacement can represent the reference point should be satisfied; when using cutting edge nodes, projection in the same direction should be performed directly. For equipment that needs to check multiple cutting edge positions, the actual safe side clearance should be checked at each position, and the result of only one point should not cover the entire shear envelope.

[0066] The local mesh is refined, and the extracted side clearance changes are compared until the change is below the error limit allocated to the numerical model by the process-allowed clearance error. The velocity, thermal boundary version, feature nodes, displacement extraction direction, and side clearance change for each operating condition are saved for subsequent fitting. If the material of the frame 1 or cutter shaft, bearing configuration, oil immersion height, oil type, or heat transfer conditions change, the mapping should be recalculated or verified; old coefficients should not be used simply because the linear velocity is the same.

[0067] Example 3: This embodiment is based on embodiment one or embodiment two, combined with... Figure 4 The construction of the continuous response surface function is explained. Table 1 presents ten sets of discrete displacement input data used for fitting demonstration, with shear linear velocities of 250, 300, 350, 400, 450, 500, 550, 600, 650, and 700 m / min; displacement and side clearance are expressed in millimeters. The change in side clearance for each set is the difference between the thermal displacements of the upper cutter shaft 3 and the lower cutter shaft 4 in the same direction. In this set of data, the side clearance increases.

[0068] Table 1 Ten sets of discrete displacements and side clearance changes

[0069] The 250 to 700 m / min range mentioned above is the data range for this offline example. It should not be assumed that any entity's edge trimmer is allowed to operate at 700 m / min based solely on this range. The available range during deployment should simultaneously meet the equipment's rated allowance, process-permitted conditions, and the verified model coverage. For example, if the actual maximum permissible speed is 600 m / min, an over-limit operation command should not be issued to the equipment simply because Table 1 contains data for 650 and 700 m / min. For equipment with an actual operating range of 200 to 600 m / min, the portion below 250 m / min requires supplementary operating condition data before the mapping can be used.

[0070] make For the number of discrete samples, in this example... ;make For the first Shear linear velocity of each sample Let it be the directional change in lateral clearance, and let Let be the vector of coefficients to be determined. At least four different velocities should be selected to ensure the column rank of the third-order regression design matrix; if more than four samples are used, solve for all samples. (12) The least squares problem is formed by combining the design matrix (composed of cubic, quadratic, linear, and constant terms for velocity) with the column vector of side clearance samples. The coefficients can be solved using orthogonal decomposition. The least squares method here minimizes the sum of squared sample residuals, but this does not mean that all ten arbitrary discrete points necessarily lie on the same third-order curve.

[0071] (13) In the formula, The directional lateral gap change predicted by the regression model; when When outputting values ​​in meters / minutes or millimeters... , , and These have the corresponding dimensions of millimeters per minute (m / min)³, millimeters per minute (m / min)², millimeters per minute (m / min), and millimeters, respectively. The coefficients recalculated from the data in Table 1 are:

[0072] .

[0073] Figure 4 In the table, "Discrete side gap change" represents the input sample in the fourth column of Table 1, and "third-order least squares fitting" represents the result of... , , and The continuous curve obtained by substituting into equation (13) Figure 4 The horizontal axis is labeled "shear linear velocity (m / min)" and the vertical axis is labeled "change in side clearance (mm)". The curve first increases and then gradually decreases within the range of this data set, indicating that even if a certain heat source increases with speed, the differential momentum of the upper cutter shaft 3 and the lower cutter shaft 4 does not necessarily increase monotonically with speed; the cubic relationship of the oil stirring power cannot be directly regarded as the only law of the change in side clearance.

[0074] Using the predicted value minus the input sample value as the residual, the maximum absolute residual obtained in this recalculation is approximately 6.7506 × 10⁻⁶. -7 Millimeters, root mean square residual approximately 3.3331 × 10⁻⁶ mm. -7 Millimeters, coefficient of determination The value is approximately 0.9999996946. The coefficient of determination represents the degree of fit within the sample set. These values ​​only reflect the consistency between the input data in Table 1 and the fitted function, and cannot be used as indicators of the measurement accuracy of the physical equipment, the accuracy of finite element prediction, or the actual compensation error.

[0075] Before deploying the controller, the predicted deviation should be verified using permissible speed conditions or equipment thermal testing results that were not involved in the fitting process. This deviation should be included in the process error budget along with side clearance positioning errors and model boundary changes. If the verification exceeds the permissible deviation, discrete operating conditions should be added, thermal boundaries corrected, or the model refitted. The model should not be validated solely based on the rounded coefficient of determination being 1.0000.

[0076] (14) Equation (14) is the step-by-step multiplication and addition calculation form of Equation (13). By writing the coefficients, speed units, side clearance units, and the allowed range of the model into the controller, errors in compensation caused by unit changes can be avoided; before calling, check whether the target speed is within the verified range.

[0077] Example 4: This embodiment is based on the aforementioned embodiments, and combines... Figure 6 This section explains the calculation, servo execution, and lock holding of the pre-bias instruction. Figure 6 The steps are as follows: “Input target shear line velocity and ideal working side clearance”, “Predict thermal steady-state side clearance change”, “Calculate static pre-bias command value”, “Cold state no-load positioning and locking”, and “Maintain locking during loaded shearing”; the listed texts correspond to the following execution steps respectively.

[0078] 1. Input the target operating condition and calculate the pre-offset The target shearing linear velocity is given by the production task. The ideal working clearance is given by the strip specifications, material, and process specifications. In the "Input Target Shear Linear Velocity and Ideal Working Side Clearance" step, first confirm the input units, the equipment's allowable speed, and the model coverage range; in the "Predict Thermal Steady-State Side Clearance Change" step, use a continuous analytical mapping function that matches the current rack 1, lubrication, and assembly configuration to calculate... .

[0079] (15) In the step of “calculating the static pre-bias command value”, the cold target side clearance is obtained according to equation (15). .when At that time, the cold-state side clearance is smaller than the ideal working side clearance; when At that time, the gap on the cold side is relatively large. This directional convention should be retained, and the absolute value of differential thermal elongation should not be unconditionally substituted into equation (15).

[0080] Taking a target shearing linear velocity of 350 m / min and an ideal working side clearance of 0.120 mm as an example, the following will be performed: , , and Substituting the coefficients into equation (13), the predicted increase in side clearance is approximately 0.011001879 mm, and the calculated target side clearance in the cold state is approximately 0.108998121 mm. If the side clearance is expressed as a six-decimal-digit number, it is 0.108998 mm; the specific number of decimal places to retain in the instruction should be determined according to the actual resolution of the adjustment mechanism and the allowable error of the process, and the number of decimal places displayed should not be regarded as the achieved mechanical positioning accuracy.

[0081] II. Correspondence between gap commands and servo position coordinates After receiving the cold target side clearance, the Programmable Logic Controller 13 (PLC) converts it into the positioning coordinates of the upper tool axis side clearance adjustment servo mechanism 12 using the existing cold tool setting calibration relationship of the equipment. The side clearance is the relative dimension between the two blades and cannot be universally applied to the motor rotation angle or linear coordinates of all servo drives without conversion.

[0082] (16) In the formula, Servo positioning coordinates for the target. For the already calibrated reference positioning coordinates, This is the cold-state side clearance measured in this coordinate system. The change rate of side clearance caused by a unit change in positioning coordinates within the target's short stroke, and . The sign should be consistent with the actual adjustment direction. If the positioning relationship has a non-negligible nonlinearity, the equipment's calibrated clearance-position mapping should be used for inverse calculation, rather than forcing the use of the linear formula (16). When the controller itself already uses the actual side clearance coordinates, its existing conversion function can complete this step.

[0083] The calibration relationship should include the influence of the actual gear and blade geometry on the side clearance, and cannot simply assume that the axial movement of the upper cutter shaft 3 is always equal to the change in blade side clearance. Through the above conversion, the output of the prediction function corresponds to the existing actuator, without the need to directly copy the transmission pair structure of other edge trimmers into the dedicated structure of this embodiment.

[0084] III. Cold-state unloaded positioning and locking In the "cold-state no-load positioning and locking" stage, it is confirmed that the equipment has reached the cold-state reference conditions used for modeling and is in a completely stopped or no-load non-biting state. Then, the programmable logic controller 13 drives the upper tool shaft side clearance adjustment servo mechanism 12 to complete the positioning, so that the upper tool 5 is in the position corresponding to the pre-bias command. Cold state is not the same as just stopped: when the equipment has just finished hot state operation and has not yet cooled down, the full amount of thermal change predicted relative to the cold state reference should not be used directly for tool setting.

[0085] Before execution, verify that the calculated cold-state side clearance is within the equipment's allowable range and that there is no blade interference. During execution, confirm positioning based on the existing position feedback from the servo mechanism, and if necessary, verify the actual side clearance according to the established tool setting procedure. Do not perform loaded shearing if the calculated side clearance is less than the equipment's minimum safety value, exceeds the adjustment stroke, positioning is incomplete, or the reference temperature is inconsistent. The above safety boundaries are given by the specific equipment and process specifications and cannot be replaced by arbitrary uniform values.

[0086] After positioning is completed, the locking function of the upper tool shaft side clearance adjustment servo mechanism 12 is activated. This locking maintains the set state of the clearance adjustment degree of freedom, not stops the shearing rotation of the upper tool shaft 3 and lower tool shaft 4. For equipment using existing mechanical self-locking or holding mechanisms, their original holding function is used; overcoming self-locking and forcibly fine-tuning during load is not a condition for implementing this method.

[0087] IV. Thermal Steady-State Compensation and Subsequent Tasks In the "locked-in during loaded shearing" stage, no further online fine-tuning of the clearance degree of freedom is performed during subsequent loaded operations. When the equipment operates continuously at the target speed and approaches the modeled thermal steady state, the differential thermal elongation of the upper cutter shaft 3 and the lower cutter shaft 4 produces corresponding changes in side clearance, which are superimposed on the pre-set reverse deviation. Under ideal calculation conditions with consistent model conditions and no prediction bias: (17) In the formula, This represents the side clearance under the target operating condition and thermal steady state. For the aforementioned example of 350 m / min, adding 0.108998121 mm and 0.011001879 mm results in approximately 0.120000 mm; this is an algebraic verification within the given model, not a definitive conclusion that the actual physical equipment reaches this value without testing. Actual deviations also include thermal model errors, positioning errors, and changes in operating condition boundaries, and should be verified according to process requirements.

[0088] For subsequent production tasks using a different target speed, after the cold-state tool setting conditions are met again, the static pre-bias command is recalculated and positioning and locking are executed. If the equipment is still hot when changing rolls, it cannot be considered to meet the cold-state reference simply because it is unloaded; this embodiment does not use the original steady-state univariate function to estimate the transient temperature distribution at this time. The tool setting strategy should be formulated only after the reference conditions are met, or after a separately established and verified corresponding model is used.

[0089] This method primarily addresses stable operating conditions at various target speeds. Factors such as start-up heating, frequent speed switching, significant oil temperature changes, and additional clearance variations caused by blade wear are not automatically covered by a steady-state function with linear velocity as the sole independent variable; without further verification, a guarantee of constant clearance throughout the entire process is not provided. By clearly defining the predicted operating conditions, cold-state reference, compensation direction, and servo physical execution relationship, this method can be repeatedly implemented under the stated applicable conditions.

Claims

1. A method for predicting thermal deformation and compensating for pre-biasing in a shear transmission system based on thermal-structural coupling, characterized in that, Includes the following steps: Step 1: Dynamic Quantization Modeling of Asymmetric Heat Sources with Different Shear Linear Velocities: The operating parameters of the edge trimmer under different shearing linear velocities are extracted, and the power of gear meshing frictional heat generation, bearing frictional heat generation, and oil sump churning dissipation power as the shearing linear velocity changes are quantitatively calculated. A dynamic mapping relationship between the input shearing linear velocity and the asymmetric heat generation rate is established. The operating parameters include the equipment transmission relationship, cutting load, representative cutting torque, and gear efficiency. Step 2: Discrete operating condition thermo-structural coupling and differential thermal elongation extraction: Several discrete typical linear velocity operating conditions are selected, and corresponding heat-generating loads and asymmetric convective heat transfer boundaries are applied in the finite element model respectively. Through steady-state heat conduction and static sequential coupling analysis, the differential thermal elongation of the upper and lower cutter shafts caused by the asymmetric thermal expansion of the frame under each shear linear velocity condition is extracted, and the resulting change in side clearance is calculated. Step 3: Construct a continuous response surface function for the change in shear line velocity and side clearance on the production line: Based on the least squares method of polynomial regression analysis, a continuous analytical mapping function is constructed with the production line shear line velocity as the independent variable and the change in side clearance as the dependent variable. Step 4: Implementation of compensation strategies for different working conditions: Using the continuous analytical mapping function as the prediction basis, for different target shearing line speeds on the production line, the corresponding side clearance adjustment amount is predicted according to the continuous analytical mapping function, and the upper cutter shaft side clearance adjustment servo mechanism is driven to adjust it, so as to achieve the stability of the side clearance under different shearing line speed conditions.

2. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 1, the heat generation power of the gear meshing friction is calculated based on the cutting torque and transmission efficiency at the corresponding shear line velocity, and the steady-state heat generation power of the gear on one side is determined according to the heat distribution relationship of the gear meshing area; the steady-state heat generation power of the gear on one side is divided by the corresponding equivalent heat generation ring volume in the finite element model to obtain the volumetric heat source load applied to the gear meshing area.

3. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 1, the structural dimension parameters and dynamic equivalent force parameters of the front main bearing and the rear adjustable bearing are extracted respectively, and the friction torque and frictional heat generation power of the two types of bearings are calculated respectively. The frictional heat generation power of each bearing is divided by its corresponding equivalent heat generation volume and applied to the corresponding bearing area in the finite element model to form a differentiated spatial heat source for the multi-support shaft system.

4. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 1, based on the oil-immersed structure at the bottom of the gearbox, the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient are extracted. The shear linear velocity is converted into the corresponding angular velocity. An oil pool churning dissipation model is established that is proportional to the cube of the angular velocity when the lubricating oil density, the lower gear churning radius, the immersion depth coefficient, and the resistance coefficient remain unchanged. The calculated oil pool churning dissipation power is then equivalent to an additional volumetric heat source and superimposed on the lower cutter shaft region.

5. The method for predicting thermal deformation and pre-biasing compensation of a scrap edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 2, in the three-dimensional finite element model, based on the immersion lubrication structure of the lower part of the gearbox and the lower cutter shaft, the lower half oil immersion zone is set as the oil convection heat transfer boundary, and the upper half air zone is set as the air natural convection heat transfer boundary. The heat transfer coefficient of the oil convection heat transfer boundary is greater than that of the air natural convection heat transfer boundary, and the medium temperature corresponding to the two types of boundaries is set respectively.

6. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 2, the temperature field obtained from the steady-state heat conduction analysis is imported into the static analysis as a temperature load, and a fixed constraint boundary is set at the bottom of the frame. The displacements of the characteristic nodes at the front end of the upper cutter shaft and the lower cutter shaft are extracted respectively in the same side clearance measurement direction. The absolute value of the difference between the two is taken as the differential thermal elongation, and the magnitude of the side clearance change and the direction of its increase or decrease are determined according to the relative position of the corresponding blades.

7. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 1, characterized in that, In step 3, the side clearance changes corresponding to multiple different shear linear velocity conditions are used as discrete samples, and a third-order polynomial regression is performed using the least squares method. The continuous analytical mapping function is: in, The shear line velocity, This represents the predicted change in side clearance at the corresponding shear linear velocity. , , and The regression coefficients are determined from the discrete samples.

8. The method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling according to claim 7, characterized in that, In step 4, the target shear linear velocity is obtained. and the ideal working side clearance required by the process The change in side clearance under the target shear linear velocity is calculated based on the continuous analytical mapping function. The static pre-bias command value is calculated according to the following formula: in, The side clearance that needs to be set during the cold tool setting stage. The increase in side clearance is positive and the decrease in side clearance is negative; the static pre-bias instruction value is sent to the programmable logic controller, which drives the upper tool axis side clearance adjustment servo mechanism to perform physical positioning compensation.

9. A method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling, as described in claim 8, is characterized in that... The physical positioning compensation is performed during the tool setting stage when the equipment is in a cold state, and the equipment is stopped or in an unloaded and non-biting state during the execution. The upper blade is positioned to the position corresponding to the static pre-bias command value by the upper blade shaft side clearance adjustment servo mechanism. When the predicted side clearance change is positive, the initial unloaded side clearance is set to be smaller than the ideal working side clearance, so as to offset the increase in hot side clearance under the target shearing linear velocity with the pre-set negative deviation.

10. A method for predicting thermal deformation and pre-biasing compensation of a fragmented edge shear transmission system based on thermal-structural coupling, as described in claim 9, is characterized in that... After the physical positioning compensation is completed, the upper tool axis side clearance adjustment servo mechanism is locked, and the positioning state is maintained without online fine-tuning during subsequent load shearing. When subsequent production tasks use different target shearing linear speeds, after the conditions of the cold tool setting stage are met again, the corresponding static pre-offset command value is recalculated and positioning compensation is performed.

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