Bridge structure of high-speed gantry machining center and guide rail mounting surface error compensation method thereof

Abstract

The invention discloses a high-speed gantry machining center bridge frame structure and a guide rail mounting surface error compensation method thereof, which considers all factors which can cause deformation of a guide rail mounting surface in the whole product period of a bridge frame, and eliminates part of variables by stipulating welding, machining, hoisting, transporting, assembling and other modes of the bridge frame. Respectively carrying out finite element analysis when the bridge is only subjected to the pressure of the cross beam and only subjected to the magnetic attraction force of the X-axis linear motor, and respectively obtaining the deformation of a certain coordinate point on the guide rail mounting surface under the two conditions; calculating the total deformation of the coordinate point on the guide rail mounting surface according to the superposition of the deformation under the two conditions; the equivalent deformation, opposite to the total deformation direction, of each point is manually machined by programming in advance in the machining process, so that the deformation caused by manual machining and the deformation caused by other factors are approximately counteracted, and finally the deformation of the bridge guide rail mounting surface is greatly reduced; the method is short in time consumption, low in cost, simple to operate and capable of quickly responding when influence factors change.

Description

Technical Field

[0001] This invention belongs to the field of vehicle engineering technology, and more specifically, relates to a bridge structure for a high-speed gantry machining center and a method for compensating for errors in the guide rail mounting surface. Background Technology

[0002] As integrated die casting technology becomes a core development direction in the automotive body field, mainstream new energy vehicle companies such as Tesla, NIO, XPeng, Li Auto, SERES, and Xiaomi have all deployed this technology, launching models and related products equipped with large integrated die-cast parts such as the front engine compartment, rear floor, and battery tray. These die-cast parts place stringent requirements on processing equipment, demanding large stroke, high speed, and high efficiency. Traditional low-speed gantry machining centers can no longer meet production needs, thus giving rise to large high-speed gantry machining centers where the X, Y, and Z axes are all driven by linear motors.

[0003] In this type of machine tool, the bridge frame, as a key load-bearing component connecting the base and the X-axis moving parts (hereinafter referred to as the crossbeam), undertakes a dual key function: on the one hand, it needs to have sufficient structural strength to support the stability of the crossbeam in high-speed, high-frequency reciprocating motion; on the other hand, it needs to strictly ensure the accuracy of the X-axis guide rail mounting surface to avoid the machine tool's machining accuracy from decreasing due to offset during the crossbeam's reciprocating motion.

[0004] However, due to their large size, large high-speed gantry machining centers typically have tall and wide-span cable trays. Furthermore, the accuracy of the X-axis guide rail mounting surface is affected by multiple complex factors, including: during manufacturing (welding deformation, deformation caused by processing techniques); during transport and assembly (stress deformation during hoisting, structural deformation caused by transportation bumps, positioning errors during assembly); and during operation (deflection deformation due to the weight of the cable tray itself, localized deformation caused by beam pressure, elastic deformation under the magnetic attraction of the X-axis linear motor). These factors combine to make the accuracy control of the X-axis guide rail mounting surface a long-standing and unresolved core pain point in the industry.

[0005] Currently, the industry mainly adopts two solutions to address this pain point, but both have significant drawbacks: One is the physical reverse compensation rework solution. This solution requires assembling the entire machine after the cable tray is processed, energizing the X-axis linear motor to simulate actual magnetic attraction, and then measuring the offset of selected points on the X-axis guide rail mounting surface segment by segment using a laser interferometer by moving the crossbeam. The deformation pattern within the complete stroke is then fitted based on the deformation trend of the selected points. Afterwards, the cable tray needs to be disassembled, and reverse compensation processing is performed according to the fitted pattern. This "assembly-measurement-disassembly-processing" process is repeatedly executed until the required accuracy is achieved. The disadvantage of this method is that the assembly and disassembly process is complex, each cycle is time-consuming, and the cable tray is prone to deformation again during hoisting, transportation, secondary processing, and reassembly, causing the initial measurement data to become invalid, further increasing the number of rework attempts and costs. The required accuracy can only be achieved by repeatedly performing the "supplementary processing-assembly-testing-disassembly-supplementary processing" process.

[0006] Another approach is the electrical program positioning compensation scheme. This scheme also involves first assembling the entire machine and energizing it to simulate magnetic attraction. The offset of the selected points on the X-axis guide rail mounting surface is then measured using a moving crossbeam and a laser interferometer. After fitting the deformation pattern, corresponding compensation amounts are written for each specific position in the electrical program. Error compensation is achieved by fine-tuning the actual positions of the Y and Z axes. The disadvantage of this method is:

[0007] Deformation fitting is difficult because cable tray deformation is caused by the coupling of multiple factors, and the deformation law has no uniform characteristics, making it difficult to accurately fit the deformation state of the entire stroke by selecting points.

[0008] The compensation work is extensive and has poor adaptability. It requires writing a separate compensation program for each location, which is extremely labor-intensive. When key parameters such as magnetic attraction force, beam weight, and processing method change, the original compensation program becomes completely invalid, and it is necessary to measure point by point and write the program again, which is time-consuming and labor-intensive.

[0009] The reliability risk is high. The compensation logic depends on the positioning accuracy of the X-axis grating ruler. If the X-axis grating ruler, which plays a positioning role, fails, the corresponding compensation amount based on a specific position will also be disordered and fail. Not only will it fail to correct errors, but it may also cause reverse deviation in machining accuracy, resulting in equipment failure or scrapped workpieces.

[0010] In summary, existing solutions cannot effectively eliminate complex interference factors, resulting in problems such as cumbersome operation, long processing time, high cost, poor accuracy and stability, and weak parameter adaptability. The industry urgently needs a high-speed gantry machining center bridge structure design that can avoid multiple interferences, is easy to operate, has controllable cost, and reliable accuracy, along with a corresponding guide rail mounting surface error compensation method. Furthermore, it is required that the design can quickly respond and generate new compensation schemes when key parameters such as magnetic attraction force and beam weight change, meeting the flexible adjustment needs of actual production. Summary of the Invention

[0011] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a cable tray structure for a high-speed gantry machining center and a method for compensating for errors in its guide rail mounting surface. This method considers all factors that can cause deformation of the guide rail mounting surface throughout the entire product lifecycle of the cable tray. By specifying the welding, processing, hoisting, transportation, and assembly processes of the cable tray, some variables are eliminated. Finite element analysis is then performed on the cable tray under two conditions: one under pressure from the crossbeam and the other under the magnetic attraction of the X-axis linear motor. The deformation A of the point with coordinates (X, Y) on the guide rail mounting surface under these two conditions is obtained. XY and B XY After eliminating other influencing factors, the total deformation of the point with coordinates (X, Y) on the guide rail mounting surface is C. XY =A XY +B XY By pre-programming during the processing, the reverse deformation amount -C at each point is artificially generated. XY This allows the deformation caused by human processing and other factors to be roughly offset, ultimately greatly reducing the deformation of the cable tray guide rail mounting surface. The structural design and compensation method of this invention have the characteristics of eliminating a large number of interference factors, taking less time, having low cost, being simple to operate, being relatively accurate, and being able to respond quickly when the influencing factors change.

[0012] To achieve the above objectives, one aspect of the present invention provides a method for compensating for the guide rail mounting surface error of a bridge structure in a high-speed gantry machining center, comprising the following steps:

[0013] S1. Eliminate interference factors: Control welding deformation, processing deformation, hoisting deformation, transportation deformation, assembly deformation, and cable tray self-weight deformation by specifying the cable tray welding method, processing status, hoisting method, transportation fixing method, and assembly status, thereby avoiding interference;

[0014] S2, Finite Element Analysis: Establish the cable tray subjected only to the crossbeam pressure F. A Only subject to the magnetic attraction force F of the X-axis linear motor B The mechanical model is defined as follows: the guide rail mounting surface is denoted as the XY plane. The coordinate system is established with the X-axis as the length direction of the cable tray, the Y-axis as the width direction of the cable tray, and the Z-axis as the height direction of the cable tray. The 0 point is the upper left corner vertex of the guide rail mounting surface in the top view of the cable tray. The X-axis coordinate is defined as the projection of the center positions of the two sliders below the crossbeam onto the X-axis.

[0015] S3. Deformation Calculation: For cases only subjected to beam pressure F A The model is analyzed by taking equally spaced points in the interval X∈[C,1 / 2L] to determine the theoretical deformation A in the Z-axis direction. XY The theoretical deformation along the Z-axis at each point is fitted to obtain the complete beam pressure F. ADeformation diagram of the guide rail mounting surface under the action; for the case where only the magnetic attraction force F of the X-axis linear motor is applied. B The model takes equally spaced points in the interval X∈[C,1 / 2L], and analyzes the deformation B in the Z-axis direction at different Y coordinates under each X coordinate. XY The deformed straight lines under each X coordinate are obtained by fitting, and then the complete X-axis linear motor magnetic attraction force F is fitted. B Deformation diagram of the guide rail mounting surface under action;

[0016] S4. According to the beam pressure F A Deformation of guide rail mounting surface A under action XY And the magnetic attraction force F of the X-axis linear motor B Deformation of guide rail mounting surface B under action XY Calculate the total deformation C at coordinate point (X,Y) on the guide rail mounting surface. XY The expression for the total deformation is: C XY =A XY +B XY According to the total deformation C XY The deformation diagram is pre-programmed with CNC to control the offset and tilt angle of the machining tool in the Z-axis direction, and a corresponding compensation deformation amount -C is pre-machined in the Z-axis direction at the coordinate point (X,Y). XY After processing, precision testing and fine-tuning are carried out, which ultimately greatly reduces the deformation of the cable tray guide rail mounting surface.

[0017] Furthermore, the cable tray structure is made of welded steel plates; the machine tool column and base are integrally welded; the cable tray has stiffening plates arranged according to topology optimization; and multiple weight-reducing holes are provided on the outer surface.

[0018] The cable tray has a guide rail mounting surface machined on its middle horizontal surface;

[0019] At least three bosses for mounting the magnetic plates of the X-axis linear motor are horizontally welded on the vertical surface above the bridge frame.

[0020] A guide rail is mounted on the guide rail mounting surface, and a slider is mounted on the guide rail. The top of the slider is connected to the crossbeam; the top surfaces of both ends of the cable tray are outside the travel of the guide rail.

[0021] The coil of the X-axis linear motor is located on the side of the crossbeam; the magnetic plate of the X-axis linear motor is mounted on the boss of the bridge frame 1.

[0022] Furthermore, the arrangement of the stiffening plates, the location of the weight-reducing holes, the location of the hoisting points, and the number and location of the bosses in the cable tray are all determined through topology optimization and finite element analysis, achieving lightweighting while meeting strength requirements.

[0023] Furthermore, the stiffening plates at the lifting points of the cable tray have been thickened, and the lifting points are located near the outer side of the cable tray to avoid the core area.

[0024] Further, step S2 includes:

[0025] S21. Based on the cable tray structure design parameters, establish a 1:1 three-dimensional geometric model of the cable tray using drawing software;

[0026] S22. For different components of the cable tray, such as the main steel plate, stiffening plate, guide rail mounting surface, boss, slider, and guide rail, select the appropriate finite element mesh type; the main steel plate adopts "hexahedral mesh", and the connection between the stiffening plate and the main steel plate adopts "transition mesh"; the mesh density is increased for the contact projection area of ​​the guide rail mounting surface, boss, slider, and guide rail.

[0027] S23. Based on the actual steel plate material used in the cable tray, query and enter the mechanical property parameters of the material, and bind the material parameters to the corresponding parts in the 3D model;

[0028] S24. Establish a right-handed rectangular coordinate system with the top left corner vertex of the guide rail mounting surface in the top view of the cable tray as the origin; the X-axis is along the length of the cable tray, the Y-axis is along the width of the cable tray, and the Z-axis is along the height of the cable tray; mark the center positions of the two sliders below the crossbeam in the coordinate system and clarify the coordinates of their projections on the X-axis; at the same time, mark the boundary coordinates of the X-axis guide rail mounting surface to define the analysis area;

[0029] S25. Set the connection surface between the bottom of the cable tray and the base as a "fixed constraint" to simulate the fixed state of the cable tray in actual use; this is for applications only subjected to crossbeam pressure F. A The mechanical model is used to calculate the pressure F exerted by the crossbeam on the guide rail mounting surface based on the design weight of the crossbeam. A , will F A A uniformly distributed load is applied to the projected area of ​​the crossbeam in contact with the guide rail via the slider; this is for applications only affected by the magnetic attraction force F of the X-axis linear motor. B Based on the mechanical model and the design parameters of the X-axis linear motor, the mutual attraction F between the magnetic plate and the coil is calculated using electromagnetic formulas. B , will F B The load is applied to the top surface of the three bosses in the form of "concentrated load", and the load distribution of each boss is proportional to the actual force-bearing area of ​​the magnetic plate, simulating the actual effect of magnetic attraction on the cable tray.

[0030] S26. Start the solver of the finite element analysis software, and perform calculations on "only subject to F" respectively. A "and only subject to F" B The model is solved to generate a raw data file containing the deformation of each node in the Z-axis direction.

[0031] Further, step S3 includes:

[0032] S31: Based on the actual working stroke of the X-axis guide rail, the X coordinate interval for analysis is locked as [C, 1 / 2L], where C is the initial offset of the stroke and L is the total length of the cable tray. Redundant data on the top surfaces at both ends of the cable tray are excluded, and only the finite element calculation results of the core working area on the guide rail mounting surface are retained.

[0033] S32. From the full-node data generated by the finite element analysis in step S26, extract only the deformation value of each node in the Z-axis direction to form a two-dimensional data matrix of "deformation of coordinate point (X,Y) in the Z-axis".

[0034] S33. Based on the two-dimensional data matrix of "deformation of coordinate point (X,Y) on the Z-axis", perform calculations for the deformation under only beam pressure F. A The deformation at that time and the magnetic attraction force F of the X-axis linear motor only B The deformation was calculated and fitted under the beam pressure F, and the result was obtained. A Deformation diagram of the guide rail mounting surface under action and the magnetic attraction force F of the X-axis linear motor only B Deformation diagram of the guide rail mounting surface under action;

[0035] S34, The fitted "only subjected to beam pressure F" A The discrete data corresponding to "deformation diagram of guide rail mounting surface under action" and "deformation diagram of guide rail mounting surface under magnetic attraction force F of X-axis linear motor only" are shown. B The discrete data corresponding to the "deformation diagram of the guide rail mounting surface under action" are stored as standardized data files, and the data sources are marked.

[0036] Furthermore, the step S33 described as being subjected only to the beam pressure F A The calculation and fitting of deformation over time includes:

[0037] Within the interval X∈[C,1 / 2L], based on the principle of balancing "accuracy requirements + computational efficiency", equally spaced sampling points are set, denoted as X1, X2...X n n is the total number of sampling points for the X coordinate;

[0038] For each sampling point on the X-axis, a reference point is selected in the Y-axis direction corresponding to that X-axis sampling point. The Z-axis deformation of this reference point is used to represent the deformation characteristics of all Y-axis points under that X-axis coordinate, forming a set of beam pressure analysis points (X1, Y1), (X2, Y1)...(X...). n ,Y1);

[0039] The deformation values ​​in the Z-axis direction corresponding to each analysis point were read using finite element analysis software and denoted as follows:

[0040] By using polynomial fitting or spline curve fitting, discrete analysis points are substituted into the fitting model to obtain the fitting curve.

[0041] Based on the final fitted curve, a two-dimensional graph of "X-axis deformation - Z-axis deformation" is plotted to obtain the result under the beam pressure F alone. A Deformation diagram of the guide rail mounting surface under action.

[0042] Furthermore, in step S33, the force F is only subject to the magnetic attraction of the X-axis linear motor. B The calculation and fitting of deformation over time includes:

[0043] Within the interval X∈[C,1 / 2L], based on the principle of balancing "accuracy requirements + computational efficiency", equally spaced sampling points are set to form a set of beam pressure analysis points X1, X2...X n ;

[0044] Multiple equally spaced sampling points are selected along the Y-axis direction corresponding to each X-axis sampling point, denoted as Y1, Y2…Y… m m represents the total number of equally spaced sampling points selected along the Y-axis corresponding to a single X-coordinate sampling point; forming the X-axis linear motor magnetic attraction force analysis point set (X... n ,Y1),(X n ,Y2)…(X n ,Y m For each X-axis sampling point, read the Z-axis deformation value of all corresponding Y-axis sampling points, and record it as...

[0045] Using the "least squares method" for discrete data By performing linear fitting, the equation of the deformed straight line in the X coordinate is obtained: B XY =O X Y+P X , of which O X P represents the slope of the deformation curve generated by the guide rail mounting surface in the X-axis coordinate. X Let X be the intersection point of the deformation curve generated by the guide rail mounting surface in the X coordinate and the Z axis; for all X-axis sampling points X1, X2…X in the interval X∈[C,1 / 2L] n The corresponding deformed linear equations were obtained by fitting all of them: Form a set of lines; The slope of the deformed curve generated when the X=n coordinate is used; The intersection of the deformation curve generated when the X=n coordinate of the guide rail mounting surface and the Z-axis;

[0046] Using the X-axis as the horizontal coordinate, the Y-axis as the vertical coordinate, and the Z-axis deformation as the height, the deformation lines corresponding to all X-axis sampling points are integrated. Then, using a "bilinear interpolation" or "surface fitting" algorithm, a continuous deformation surface covering the entire X∈[C,1 / 2L] and Y∈[0,W] region is constructed; W is the width of the guide rail mounting surface.

[0047] Based on the fitted surface, plot a 3D color cloud map or a 2D contour map of the "XY coordinates - Z-axis deformation" to obtain the magnetic attraction force F of the linear motor only affecting the X-axis. B Deformation diagram of the guide rail mounting surface under action.

[0048] Further, step S4 includes:

[0049] S41. Retrieve the data from the standardized data file archived in step S34, specifically the data under "only subjected to beam pressure F". A "Deformation data of guide rail mounting surface under action" and "Data on magnetic attraction force F of X-axis linear motor only" B "Deformation data of guide rail mounting surface under action"; only subjected to crossbeam pressure F A The deformation data of the guide rail mounting surface under the action is A corresponding to the X coordinate. XY Value; only affected by the magnetic attraction force F of the X-axis linear motor. B The deformation data of the guide rail mounting surface under action is the B corresponding to the coordinate point (X,Y). XY value;

[0050] S42. For each coordinate point (X,Y) on the guide rail mounting surface, according to formula C XY =A XY +B XY Calculate the total deformation C XY Among them, A XY Let the coordinate point (X,Y) be under the beam pressure F A Z-axis deformation under action; B XY The magnetic attraction force F of the linear motor at coordinate point (X,Y) on the X-axis B Z-axis deformation under action;

[0051] S43, Compare C with adjacent coordinate points XY If a sudden change in deformation occurs, backtrack the deformation data from step S3 and check A. XY Or B XY Is there an error in the calculation? Based on the strength requirements of the cable tray structure, determine the maximum C. XY If the value is within the elastic deformation range of the material, then the cable tray structure design needs to be re-optimized, and then return to step S2 to perform finite element analysis again.

[0052] S44. Based on the core objective of "compensating for total deformation", determine the compensation deformation amount for each coordinate point (X,Y) as -C. XY ;

[0053] S45. For each coordinate point (X,Y), the compensation deformation amount -C XY Converted into a Z-axis offset command for the machining tool; if C XY If the value is positive, the tool needs to be offset upwards by -C. XY If C XYIf the value is negative, the tool needs to be offset downwards by -C. XY ; Targeting F B The tilting deformation of the guide rail mounting surface under the action is addressed by adding a tool tilt angle command to the programming; based on the X-axis... The value is used to calculate the tilt angle that the tool needs to be adjusted.

[0054] S46. The effective range of compensation programming is defined as X∈[C,1 / 2L] and Y∈[0,W].

[0055] S47. Based on the determined Z-axis offset and tilt angle parameters, use CNC programming software to write a CNC program for the finishing of the guide rail mounting surface; import the written program into CNC simulation software to build a virtual environment consistent with the actual machining, and simulate the machining process of the guide rail mounting surface; check the 3D model of the simulated machining guide rail mounting surface, measure the actual Z-axis dimension of each coordinate point (X,Y), and verify whether the deviation from the "theoretical design dimension" is ≤3μm. If the deviation exceeds the standard, adjust the programming parameters until the simulation result is qualified.

[0056] S48. According to the processing requirements of step S1, fix the cable tray vertically on the machine tool, and calibrate the verticality of the cable tray using a level and dial indicator; import the verified CNC program into the machine tool, select the non-core area of ​​the guide rail mounting surface for trial cutting, measure the Z-axis dimension of the trial cutting area, and compare the deviation between the theoretical compensation value and the actual processing value: if the deviation is ≤2μm, it means that the program matches the processing status, and full-area compensation processing can be started; if the deviation is >2μm, check the accuracy of the machine tool and the fixing rigidity of the cable tray, adjust and re-trial cut until the deviation is acceptable;

[0057] Start the CNC program and perform full-area compensation machining on the X∈[C,1 / 2L] and Y∈[0,W] regions of the guide rail mounting surface. During the machining process, monitor the Z-axis coordinate feedback value of the machine tool in real time to ensure that the tool offset is consistent with the programming instructions. If the coordinate deviation is >1μm, stop the machining immediately, troubleshoot the fault, and then continue.

[0058] S49. After processing, use a laser interferometer to measure the flatness of the guide rail mounting surface for preliminary accuracy testing; if the test finds that the flatness deviation in a local area is >5μm, retrieve the C value for that area. XY Calculate the data, analyze the causes of the deviation, adjust the compensation programming parameters for the area accordingly, and perform secondary processing. After secondary processing, check the flatness again to ensure that the error of the entire area is ≤5μm. At the same time, record the correspondence between the compensation processing parameters and the actual accuracy test results to form a process database.

[0059] Furthermore, the welding deformation control in step S1 includes: during the welding process, by reasonably setting the bevel of each sub-component, the lap joint method between sub-components, following a reasonable welding sequence and direction, and adding auxiliary measures, the main direction of subsequent stress release is controlled to be parallel to the X-axis guide rail mounting surface while reducing welding stress;

[0060] Deformation control during hoisting includes thickening the steel plates at the hoisting points, ensuring that the actual usable portion of the guide rail mounting surface avoids the hoisting points, and setting the hoisting points on the outer side near the cable tray to avoid the core area.

[0061] Assembly deformation control includes ensuring that the cable tray remains vertically fixed during assembly, consistent with actual operation.

[0062] Self-weight deformation control includes welding the machine tool column and base into a single unit, which significantly reduces the height of the bridge frame and maintains vertical machining during processing, consistent with actual work.

[0063] The deformation control during transportation includes: the cable tray is loaded onto the vehicle after semi-finishing. The cable tray is fixed by special tooling during loading and remains upright, consistent with its state during processing and use. After loading, it is circulated in a designated area nearby for a period of time before being unloaded for finishing. After finishing, it is circulated again, unloaded, and then the accuracy of the cable tray is calibrated and final supplementary processing is performed.

[0064] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0065] (1) The cable tray structure and guide rail mounting surface error compensation method of the high-speed gantry machining center of the present invention can effectively solve the industry's pain point problem; the cable tray structure design scheme and error compensation method consider all factors that will cause deformation of the guide rail mounting surface during the entire product cycle of the cable tray. By specifying the welding, processing, hoisting, transportation, and assembly methods of the cable tray, some variables are eliminated. Then, finite element analysis is performed on the cable tray when it is only subjected to the pressure of the crossbeam and when it is only subjected to the magnetic attraction force of the X-axis linear motor, respectively, to obtain the deformation A of the point with coordinates (X, Y) on the guide rail mounting surface under these two conditions. XY and B XY After eliminating other influencing factors, the total deformation of the point with coordinates (X, Y) on the guide rail mounting surface is C. XY =A XY +R XY By pre-programming during the processing, the reverse deformation amount -C at each point is artificially generated. XYThis design and compensation method effectively eliminates deformation caused by human processing and other factors, thereby significantly reducing the deformation of the cable tray guide rail mounting surface. The structure and compensation method are characterized by eliminating a large number of interference factors, requiring less time, having lower cost, being simple to operate, being relatively accurate, and being able to respond quickly when influencing factors change.

[0066] (2) The high-speed gantry machining center bridge structure and its guide rail mounting surface error compensation method of the present invention address the industry pain point that the X-axis guide rail mounting surface accuracy is difficult to control due to the "high height and large span" of the bridge structure of large high-speed gantry machining centers and the superposition of multiple factors such as welding, processing, hoisting, transportation, assembly, self-weight, beam pressure, and motor magnetic attraction. Through the design logic of full-cycle factor coverage and targeted interference elimination, avoidable deformation is avoided from the source (such as reducing the height of the bridge structure by integrating the column and base welding, limiting the hoisting position and thickening the stiffener to reduce hoisting deformation, and standardizing the welding process to control the stress release direction). Then, the core stress deformation of beam pressure and motor magnetic attraction is focused through finite element analysis, and finally the total deformation is offset by reverse compensation processing. In practical applications, the final deformation of the guide rail mounting surface can be greatly reduced, which can meet the processing requirements of "large stroke, high speed and high efficiency" of integrated die castings, solve the problems of insufficient accuracy of traditional high-speed gantry machining centers and easy failure of existing compensation schemes, and ensure the stability of machining accuracy during long-term operation of machine tools.

[0067] (3) The high-speed gantry machining center bridge structure and its guide rail mounting surface error compensation method of the present invention addresses the shortcomings of traditional solutions, which suffer from high analysis difficulty, increased computational load, and low fitting accuracy due to the lack of reasonable simplification of deformation dimensions and the need to handle complex three-dimensional spatial deformation problems. It innovatively focuses on the core requirement of guide rail mounting surface accuracy control, paying attention only to deformation in the Z-axis direction (vertical accuracy directly affects machining error) and ignoring the X and Y-axis offsets, which have minimal impact on accuracy, thus simplifying the three-dimensional spatial deformation problem into a one-dimensional linear deformation problem. Simultaneously, considering the characteristic of "consistent deformation of the same X-axis T-axis" under beam pressure, single Y-reference point sampling is adopted; and considering the characteristic of "deformation as an inclined surface" under motor magnetic attraction, linear fitting simplifies the Y-axis deformation calculation, significantly reducing the computational load of finite element analysis and data fitting, shortening the analysis cycle, and controlling the fitting deviation within 5µm with a linear fitting goodness R. 2 With a value ≥0.95, the method of this invention simplifies the process without reducing accuracy, making it easier to implement and apply.

[0068] (4) The error compensation method for the bridge structure and guide rail mounting surface of the high-speed gantry machining center of the present invention addresses the existing physical compensation scheme of "assembly-measurement-disassembly-rework" and the electrical compensation scheme of "point-by-point programming + failure due to parameter changes". By using a mode of finite element analysis in advance and reverse compensation machining, the entire machine does not need to be repeatedly disassembled and reassembled. Only one analysis and programming need to be completed before machining to achieve the required accuracy. At the same time, stress is eliminated by simulating aging through vertical circulation transportation after semi-finishing, eliminating the need for additional investment in special equipment such as post-weld vibration and hammering, thus reducing equipment and labor costs. From the perspective of the whole process, the present invention significantly shortens the accuracy calibration cycle and reduces the rework rate to almost zero, which can significantly improve production efficiency and reduce the manufacturing and maintenance costs of large high-speed gantry machining centers.

[0069] (5) The high-speed gantry machining center bridge structure and its guide rail mounting surface error compensation method of the present invention are simple to operate and highly adaptable, and can meet the dynamic production needs. The stiffener arrangement, weight reduction hole position, and hoisting point setting are all predetermined through topology optimization and finite element analysis. During processing and assembly, only the standard needs to be followed. In terms of compensation method, the finite element analysis process can be realized through standardized software templates. The compensation amount calculation and CNC programming can be automatically linked, without relying on complex manual debugging, and the operation threshold is low. More importantly, when the core influencing factors such as beam weight and motor magnetic attraction force change, only the beam pressure and X-axis linear motor magnetic attraction force parameters in the finite element model need to be adjusted, and the total deformation and compensation amount need to be recalculated to quickly generate a new compensation scheme. There is no need to "re-measure and rewrite the program point by point" like traditional electrical compensation, which greatly improves the response speed to changes in production conditions and can meet the flexible processing needs of integrated die-cast parts of different specifications.

[0070] (5) The high-speed gantry machining center bridge structure and its guide rail mounting surface error compensation method of the present invention ensures that the self-weight deformation of the bridge is offset during the machining stage by unifying the posture throughout the entire process of vertical machining, vertical transportation, and vertical assembly, thus avoiding additional deformation caused by subsequent posture changes. At the same time, residual stress is eliminated by cyclic transportation to simulate aging, reducing the accuracy drift caused by stress release during long-term use and ensuring the long-term reliability of the guide rail mounting surface accuracy. The present invention requires archiving all process data (structural parameters, finite element model, compensation program, accuracy test report, etc.) and establishing a correlation ledger of products, processes, and accuracy. If accuracy problems occur during subsequent operation and maintenance, the cause can be quickly traced and targeted adjustments can be made, avoiding blind debugging caused by data loss in traditional solutions, and reducing equipment operation and maintenance risks and downtime losses. Attached Figure Description

[0071] Figure 1 Isometric drawing of a cable tray for a standard large-scale high-speed gantry machining center;

[0072] Figure 2This is an isometric schematic diagram of a bridge structure for a high-speed gantry machining center according to an embodiment of the present invention;

[0073] Figure 3 This is a top view schematic diagram of a bridge structure for a high-speed gantry machining center according to an embodiment of the present invention;

[0074] Figure 4 This is a side view of a bridge structure for a high-speed gantry machining center according to an embodiment of the present invention;

[0075] Figure 5 This is a side view of the bridge structure and crossbeam assembly of a high-speed gantry machining center according to an embodiment of the present invention.

[0076] Figure 6 This is a schematic diagram of the overall stress distribution of a high-speed gantry machining center bridge structure and crossbeam after assembly, according to an embodiment of the present invention.

[0077] Figure 7 This is a schematic diagram illustrating the stress on the bridge structure and crossbeam of a high-speed gantry machining center during horizontal assembly, according to an embodiment of the present invention.

[0078] Figure 8 This is a schematic diagram of the coordinate system construction of a high-speed gantry machining center bridge structure under only crossbeam pressure according to an embodiment of the present invention;

[0079] Figure 9 This is a schematic diagram of the stress and deformation of a bridge structure of a high-speed gantry machining center under the pressure of only the crossbeam, according to an embodiment of the present invention.

[0080] Figure 10 This is a schematic diagram of the stress and deformation of a bridge structure of a high-speed gantry machining center under the magnetic attraction of a linear motor, according to an embodiment of the present invention.

[0081] Figure 11 This is a flowchart illustrating a method for compensating for errors in the bridge structure and guide rail mounting surface of a high-speed gantry machining center according to an embodiment of the present invention.

[0082] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-Cable tray, 11-Firming plate, 12-Weight reduction hole, 13-Guide rail mounting surface, 131-Side of guide rail mounting surface, 132-Inclined surface, 14-Top surfaces at both ends of the cable tray, 15-Boss, 2-Guide rail, 21-Slider, 211-Projection, 3-Crossbeam, 4-Coil, 5-Magnetic plate. Detailed Implementation

[0083] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0084] like Figures 1-6 As shown, one aspect of the present invention provides a bridge structure for a high-speed gantry machining center and a method for compensating for errors in its guide rail mounting surface. The bridge 1 is welded from steel plates; the machine tool column and base are integrally welded and not welded to the bridge 1; the bridge 1 has stiffening plates 11 arranged internally according to topology optimization, and multiple weight-reducing holes 12 are provided on its outer surface; the hoisting position of the bridge 1 is predetermined, the stiffening plates 11 at the hoisting point of the bridge 1 are thickened, and the hoisting point is close to the outer side of the bridge to avoid the core area; the middle horizontal surface of the bridge 1 is machined with... The guide rail mounting surface 13 and the top surfaces 14 at both ends of the bridge frame are located outside the travel of the guide rail 2. At least three bosses 15 for mounting the magnetic plates of the X-axis linear motor are horizontally welded on the vertical surface above the bridge frame 1. When the bridge frame 1 is in use, the machine tool column is fixed to the base. The guide rail 2 is mounted on the guide rail mounting surface 13, and the slider 21 is mounted on the guide rail 2. The top of the slider 21 is connected to the crossbeam 3. The crossbeam 3 is connected to the X-axis guide rail mounting surface 13 of the bridge frame 1 through two sliders 21 and the guide rail 2. The crossbeam 3 is the X-axis moving component, and the pressure F generated by the weight of the crossbeam on the bridge frame 1 is... A The coil 4 of the X-axis linear motor is located on the side of the crossbeam 3; the magnetic plate 5 of the X-axis linear motor is mounted on the boss 15 of the bridge frame 1; the magnetic attraction between the magnetic plate 5 and the coil 4 is F. B The arrangement of the stiffening plates 11, the location of the holes 12 for weight reduction, the location of the hoisting points, and the number and location of the bosses 15 of the cable tray 1 are all determined through topology optimization and finite element analysis, so as to achieve lightweighting while meeting the strength requirements.

[0085] like Figure 11 As shown, the X-axis guide rail mounting surface error compensation method of the cable tray structure includes the following steps:

[0086] S1. Eliminate interference factors: Control welding deformation, processing deformation, hoisting deformation, transportation deformation, assembly deformation, and cable tray self-weight deformation by specifying the cable tray welding method, processing status, hoisting method, transportation fixing method, and assembly status, thereby avoiding interference;

[0087] S2, Finite Element Analysis: Establish the cable tray subjected only to the crossbeam pressure F. A Only subject to the magnetic attraction force F of the X-axis linear motor BThe mechanical model is defined as follows: the guide rail mounting surface is denoted as the XY plane. The coordinate system is established with the X-axis as the length direction of the cable tray, the Y-axis as the width direction of the cable tray, and the Z-axis as the height direction of the cable tray. The 0 point is the upper left corner vertex of the guide rail mounting surface in the top view of the cable tray. The X-axis coordinate is defined as the projection of the center positions of the two sliders below the crossbeam onto the X-axis.

[0088] S3. Deformation Calculation: For cases only subjected to beam pressure F A The model takes equally spaced points (X1,Y1), (X2,Y1)...(X) in the interval [C,1 / 2L]. n ,Y1), analyze the theoretical deformation of each point in the Z-axis direction. The complete beam pressure F is obtained by fitting the theoretical deformation along the Z-axis at each point. A Deformation diagram of the guide rail mounting surface under the action; for the case where only the magnetic attraction force F of the X-axis linear motor is applied. B The model takes equally spaced points X1, X2, ... in the interval X∈[C,1 / 2L], and analyzes the deformation B in the Z-axis direction by taking different Y-coordinate points under each X coordinate. XY The deformation line B under each X coordinate is obtained by fitting. XY =O X Y+P X (O X Let P be the slope. X (The intersection of the deformed straight line and the Z-axis) is used to fit the complete X-axis linear motor magnetic attraction force F. B Deformation diagram of the guide rail mounting surface under action;

[0089] S4. According to the beam pressure F A Deformation of guide rail mounting surface A under action XY And the magnetic attraction force F of the X-axis linear motor B Deformation of guide rail mounting surface B under action XY Calculate the total deformation C at coordinate point (X,Y) on the guide rail mounting surface. XY The expression for the total deformation is: C XY =A XY +B XY According to the total deformation C XY The deformation diagram is pre-programmed with CNC to control the offset and tilt angle of the machining tool in the Z-axis direction, and a corresponding compensation deformation amount -C is pre-machined in the Z-axis direction at the coordinate point (X,Y). XY After processing, precision testing and fine-tuning are carried out, which ultimately greatly reduces the deformation of the cable tray guide rail mounting surface.

[0090] Furthermore, in step S1, a large number of interfering factors are eliminated by specifying the welding, processing, hoisting, transportation, and assembly of the cable tray. Combined with theoretical finite element analysis and actual operation, error compensation of the guide rail mounting surface can be completed quickly, at low cost, in a simple and relatively accurate manner, without the need for rework.

[0091] Step S1, welding deformation control, includes: during the welding process, by reasonably setting the bevels of each sub-component, the overlapping method between sub-components, following a reasonable welding sequence and direction, and adding some auxiliary measures, while reducing welding stress, controlling the main direction of subsequent stress release to be parallel to the X-axis guide rail mounting surface, thus reducing the impact of deformation caused by welding stress release on the final result; the main factor affecting the accuracy of the X-axis guide rail mounting surface is its deformation in the vertical direction, while under these welding conditions, stress release mainly causes deformation in the horizontal direction, which has a small impact on the accuracy we are concerned with, making the deformation caused by welding negligible;

[0092] Step S1, deformation control during hoisting, includes: pre-setting hoisting points; thickening the steel plates at the hoisting points; analyzing the cable tray hoisting process using finite element analysis to confirm that the maximum internal stress is much less than the yield strength of the steel, and the deformation of the cable tray is elastic deformation, which will recover after the applied load is removed; avoiding the area near the hoisting points where the stress is greatest during hoisting; setting the hoisting points close to the outer side of the cable tray to avoid the core area; for a given cable tray weight, the further out the hoisting point is, the larger the angle between the sling and the vertical plane, and the greater the tension the sling will bear; selecting appropriate slings after calculation, and maintaining a small range of motion during hoisting to reduce the impact on the cable tray and the release of residual stress; making the deformation caused by hoisting negligible.

[0093] The deformation control during transportation in step S1 includes: after the cable tray is semi-finished, it is loaded onto a vehicle. During loading, the cable tray is fixed with special tooling and remains upright, consistent with its state during processing and use. After loading, it is circulated in a designated area nearby for a period of time before being unloaded for finishing. After finishing, it is circulated again, unloaded, and the accuracy of the cable tray is calibrated and final supplementary processing is performed. The principle of this simulated transportation is that the welded parts will bump when the road surface is uneven. By simulating the post-weld vibration method and hammering method, the residual welding stress is effectively released under the condition that the cable tray is fixed in the same way as during use, reducing the error caused by subsequent stress release. After the two simulated transportations, the residual stress of the cable tray has been largely eliminated. The deformation caused by the release of residual stress during the final actual transportation is very small, and the main direction of stress release is parallel to the X-axis guide rail mounting surface, which has little impact on the accuracy we are concerned about. Thus, the deformation caused by transportation can be basically ignored.

[0094] Step S1 assembly deformation control includes: During assembly, the cable tray remains vertically fixed, consistent with actual operation; the cable tray is mainly subjected to its own weight and forces applied during assembly, such as the tightening force of guide rail mounting screws and the clamping force of simple locating pins on the side of the guide rail. The direction of gravity relative to the cable tray differs between horizontal and vertical installations, resulting in different directions of primary deformation; during horizontal installation, the X-axis guide rail mounting surface 131 deforms more significantly due to the cable tray's own weight (e.g., ...). Figure 7 As shown), the clamping force F generated by the simple locating pin 压 The deformed side of the guide rail is compressed; when the equipment is actually used and the cable tray is fixed vertically, the relationship between the direction of gravity and the cable tray changes, and the deformation of the side of the guide rail mounting surface caused by gravity will decrease and spring back. After the new force balance, the magnitude of the internal stress of the cable tray will change and eventually produce local deformation; therefore, when the cable tray is kept vertically fixed during the assembly process, the deformation caused by assembly can be basically ignored.

[0095] Step S1, the control of self-weight deformation, includes: welding the machine tool column and the machine tool base together as a whole, thereby significantly reducing the height of the cable tray; the cable tray of the present invention maintains the same vertical fixation during processing and use, and before processing, all parts, including the guide rail mounting surface, have already deformed under the action of gravity. Therefore, whether during or after processing, the deformation of the guide rail mounting surface under the action of gravity will not change again. The processing completed under these conditions is equivalent to having considered the influence of gravity and successfully offsetting it; in order to ensure that the processing state is consistent with the use state, the present invention welds the machine tool column and the machine tool base together as a whole, thereby significantly reducing the height of the cable tray, enabling it to be vertically fixed for processing by conventional machine tools and also facilitating vertical transportation; thus, the deformation caused by the self-weight of the cable tray can be basically ignored;

[0096] Step S1 of this invention eliminates a large number of interfering factors by specifying the welding, processing, hoisting, transportation, and assembly of the cable tray. Combining theoretical finite element analysis and practical operation, it can quickly, cost-effectively, simply, and relatively accurately complete the error compensation of the guide rail mounting surface without rework. During the welding process, by reasonably setting the bevels of each component, the overlapping method between components, following a reasonable welding sequence and direction, and adding some auxiliary measures, the welding stress is reduced while controlling the main direction of subsequent stress release to be parallel to the X-axis guide rail mounting surface, thereby reducing the impact of deformation caused by welding stress release on the final result.

[0097] Further, step S2 includes:

[0098] S21. Geometric Model Construction: Based on the cable tray structure design parameters, a 1:1 three-dimensional geometric model of the cable tray is established using drawing software to ensure that the model is completely consistent with the actual processing dimensions; details in the cable tray structure that do not affect the accuracy of the mechanical analysis are simplified, redundant geometric features are deleted, and the amount of finite element calculation is reduced; at the same time, the complete geometric shape of the core load-bearing components is preserved to avoid analysis errors caused by simplification; the cable tray structure design parameters include steel plate material, thickness, arrangement dimensions of stiffening plates 11, number and diameter of weight reduction holes 12, position and height of bosses 15, and area of ​​guide rail mounting surface 13;

[0099] S22. Mesh Generation: For different components of the cable tray, such as the main steel plate, stiffener 11, and boss 15, select appropriate finite element mesh types; the main steel plate adopts a "hexahedral mesh" to ensure calculation accuracy, and the connection between the stiffener and the main steel plate adopts a "transition mesh" (such as a pyramidal mesh) to avoid mesh distortion in stress concentration areas; for core stress areas such as the guide rail mounting surface 13, boss 15, and the contact projection area between the slider 21 and the guide rail 2, the mesh density is increased.

[0100] S23. Assigning Material Parameters: Based on the actual steel plate material used in the cable tray, query and enter the mechanical property parameters of the material, including elastic modulus, Poisson's ratio, density, and yield strength; bind the material parameters to the corresponding components in the 3D model;

[0101] S24. Coordinate System and Key Position Definition: A right-handed rectangular coordinate system is established with the upper left corner vertex of the X-axis guide rail mounting surface 13 in the cable tray top view as the origin (0 point). Figure 8 (As shown); the X-axis is along the length of the cable tray (consistent with the direction of movement of the crossbeam 3), the Y-axis is along the width of the cable tray (perpendicular to the direction of movement of the crossbeam), and the Z-axis is along the height of the cable tray (perpendicular to the guide rail mounting surface 13); mark the center positions of the two sliders 21 below the crossbeam 3 in the coordinate system, and clarify the coordinates of their projections 211 on the X-axis (i.e., the X-coordinate reference for subsequent deformation calculation); at the same time, mark the boundary coordinates of the X-axis guide rail mounting surface 13 to define the analysis area;

[0102] S25. Simulate the fixed state of the cable tray in actual use: Set the connection surface between the bottom of the cable tray and the base as a "fixed constraint" (restricting the translational and rotational degrees of freedom in the X, Y, and Z directions) to ensure consistency with the constraints when the cable tray is assembled vertically.

[0103] For only subjected to crossbeam pressure F A Mechanical models (such as) Figure 9 As shown), based on the design weight of the crossbeam 3 (including the weight of the slider 21 and the X-axis linear motor coil 4), calculate the pressure F of the crossbeam on the guide rail mounting surface 13. A (F A =Total weight of the beam (direction along the negative Z-axis); FA The load is applied in the form of a "uniformly distributed load" to the projection area of ​​the crossbeam 3 that contacts the guide rail 2 through the slider 21 (i.e., the position of the slider 21 on the guide rail mounting surface 13), ensuring that the load application position is completely matched with the actual force position.

[0104] For only subject to the magnetic attraction force F of the X-axis linear motor B Mechanical models (such as) Figure 10 As shown), based on the design parameters of the X-axis linear motor (such as the magnetic flux of magnetic plate 5 and the current intensity of coil 4), the mutual attraction F between magnetic plate 5 and coil 4 is calculated using electromagnetic formulas. B (Direction along the Y-axis, pointing towards the side of magnetic plate 5); F B The load is applied to the top surface of the three bosses 15 (the mounting area of ​​the magnetic plate 5) in the form of a "concentrated load", and the load distribution of each boss 15 is proportional to the actual force-bearing area of ​​the magnetic plate 5, simulating the actual effect of magnetic attraction on the cable tray.

[0105] S26. Solver Parameter Settings and Calculations: Since the cable tray's stress deformation is a small static deformation, select the "Static Structural Analysis" solution type to avoid redundant calculations caused by dynamic analysis; set displacement convergence criteria to ensure stable and reliable calculation results; start the solver of the finite element analysis software and perform calculations on the "only subjected to F" solution. A "Only subject to F" B The model is solved to generate an original data file containing the deformation of each node (especially all nodes on the guide rail mounting surface 13) in the Z-axis direction;

[0106] Further, step S3 includes:

[0107] S31. Determining the data filtering range: Based on the actual working stroke of the X-axis guide rail, the X coordinate range for analysis is locked as [C, 1 / 2L] (C is the initial offset of the stroke, and L is the total length of the cable tray). Redundant data on the top surface 14 at both ends of the cable tray (non-guide rail stroke area) is excluded, and only the finite element calculation results of the core working area on the guide rail mounting surface 13 are retained.

[0108] S32, Data Dimension Focus: From the full node data generated by the finite element analysis in step S26, only the deformation value of each node in the Z-axis direction is extracted (because the error compensation only focuses on the vertical accuracy of the guide rail mounting surface, the offset in the X and Y axes does not affect the final compensation effect), forming a two-dimensional data matrix of "deformation of coordinate point (X,Y) in the Z-axis", which simplifies the subsequent calculation dimensions;

[0109] S33. Deformation Calculation and Fitting: Based on the two-dimensional data matrix of "deformation of coordinate point (X,Y) on the Z-axis", the deformation is calculated under the beam pressure F. A The deformation at that time and the magnetic attraction force F of the X-axis linear motor only BThe deformation was calculated and fitted under the beam pressure F, and the result was obtained. A Deformation diagram of the guide rail mounting surface under action and the magnetic attraction force F of the X-axis linear motor only B Deformation diagram of the guide rail mounting surface under action;

[0110] The step S33 described only as being subjected to beam pressure F A The calculation and fitting of deformation over time includes:

[0111] Points are evenly spaced along the X-axis. Within the interval X∈[C,1 / 2L], sampling points are set at equal intervals according to the principle of balancing "accuracy requirements + computational efficiency", denoted as X1, X2...X n n is the total number of sampling points for the X coordinate;

[0112] A reference point is determined along the Y-axis. For each sampling point on the X-axis, a reference point is selected along the Y-axis. The Z-axis deformation of this reference point represents the deformation characteristics of all Y-coordinate points under that X-coordinate, forming a set of beam pressure analysis points (X1, Y1), (X2, Y1)...(X...). n ,Y1);

[0113] The deformation values ​​in the Z-axis direction corresponding to each analysis point were read using finite element analysis software and denoted as follows:

[0114] By using polynomial fitting or spline curve fitting, discrete analysis points are substituted into the fitting model to obtain the fitting curve.

[0115] Based on the final fitted curve, a two-dimensional graph of "X-axis deformation - Z-axis deformation" is plotted to obtain the result under the beam pressure F alone. A Deformation diagram of the guide rail mounting surface under action; the diagram should be labeled with the X-axis interval [C, 1 / 2L], the location and value of the maximum deformation;

[0116] The step S33 described is only subject to the magnetic attraction force F of the X-axis linear motor. B The calculation and fitting of deformation over time includes:

[0117] Points are evenly spaced along the X-axis. Within the interval X∈[C,1 / 2L], sampling points are set at equal intervals according to the principle of balancing "accuracy requirements + computational efficiency," forming a set of beam pressure analysis points X1, X2…X n ;

[0118] Multi-point sampling is performed along the Y-axis due to the magnetic attraction force F of the linear motor on the X-axis. B Under the action, the guide rail mounting surface deforms into an inclined surface with characteristic 132 (e.g. Figure 10 As shown in the figure, the deformation is different at different Y coordinates under the same X coordinate. Therefore, multiple equally spaced sampling points are selected in the Y-axis direction corresponding to each X-axis sampling point, denoted as Y1, Y2...Ym m represents the total number of equally spaced sampling points selected along the Y-axis corresponding to a single X-coordinate sampling point; forming the X-axis linear motor magnetic attraction force analysis point set (X... n ,Y1),(X n ,Y2)…(X n ,Y m For each X-axis sampling point, read the Z-axis deformation value of all corresponding Y-axis sampling points, and record it as...

[0119] Using the "least squares method" for discrete data By performing linear fitting, the equation of the deformed straight line in the X coordinate is obtained: B XY =O X Y+P X Among them, O X This refers to the slope of the deformation curve generated under the X-axis of the guide rail mounting surface, P. X This refers to the intersection of the deformation curve generated by the guide rail mounting surface in the X coordinate and the Z axis, reflecting the basic deformation offset of the guide rail mounting surface in the X coordinate; for all X-axis sampling points X1, X2…X in the interval X∈[C,1 / 2L] n The corresponding deformed linear equations were obtained by fitting all of them: Form a set of lines; The slope of the deformed curve generated when the X=n coordinate is used; That is, the intersection of the deformation curve generated when the X=n coordinate of the guide rail mounting surface and the Z-axis;

[0120] Using the X-axis as the horizontal coordinate, the Y-axis as the vertical coordinate, and the Z-axis deformation as the height, the deformation lines corresponding to all X-axis sampling points are integrated. Then, using a "bilinear interpolation" or "surface fitting" algorithm, a continuous deformation surface covering the entire X∈[C,1 / 2L] and Y∈[0,W] region is constructed; W is the width of the guide rail mounting surface.

[0121] Based on the fitted surface, plot a 3D color cloud map (or a 2D contour map) of the "XY coordinates - Z-axis deformation" to obtain the magnetic attraction force F of the linear motor only affecting the X-axis. B Deformation diagram of the guide rail mounting surface under action; the diagram should indicate the area of ​​maximum deformation and the X-coordinate position of the largest tilt slope.

[0122] S34, The fitted "only subjected to beam pressure F" A Discrete data corresponding to "deformation diagram of guide rail mounting surface under action" and "deformation diagram of guide rail mounting surface under magnetic attraction force F of X-axis linear motor only" B The discrete data corresponding to the "deformation diagram of the guide rail mounting surface under action" are stored as standardized data files and the data source is marked so that they can be directly called when calculating the total deformation in the subsequent step S4, while ensuring data traceability.

[0123] Furthermore, in step S33, only the beam pressure F is applied. A When calculating and fitting the deformation, since both sliders must run on the guide rail, some positions cannot be reached, and the beam can only move within the X-coordinate range [C,D] (see...). Figure 8 The length of the guide rail mounting surface along the X-axis is denoted as L. Since the cable tray is a symmetrical component, it is only subjected to the pressure F of the crossbeam in addition to gravity. A Furthermore, its direction is vertically downwards, consistent with gravity, therefore the final deformation is also symmetrical; only the deformation of X within [C, 1 / 2L] needs to be studied. Since the static stiffness of points with the same X coordinate but different Y coordinates on the guide rail mounting surface is basically the same, the beam pressure F... A The stress transmitted through the guide rail is completely vertically downward on the entire guide rail mounting surface. Therefore, the stress and deformation of points with the same X coordinate but different Y coordinates are basically the same. Assuming that the crossbeam is located at X=n, we complete the modeling and perform the corresponding static stress analysis. We take several points in the interval X∈[C,1 / 2L], with equal spacing between each point. We perform finite element analysis on each point to obtain the theoretical deformation. Then, we fit the deformation of the points on the entire guide rail mounting surface through these point lattices to obtain the complete deformation diagram of the guide rail mounting surface under the action of the crossbeam.

[0124] In step S34, only the magnetic attraction force F of the X-axis linear motor is applied. B When calculating and fitting the deformation, it is assumed that the crossbeam is located at X=n. After modeling and performing the corresponding static stress analysis, when X=n, the overall deformation trend of the guide rail mounting surface is inclined due to the magnetic attraction of the linear motor. Several different Y coordinates are selected when the X=n coordinate of the guide rail mounting surface to obtain the deformation in the Z-axis direction. Based on these selected points, a straight line that conforms to the actual deformation trend is fitted. in The slope of the deformed curve generated when the X=n coordinate is used; Let X be the intersection point of the deformation curve generated when the X=n coordinate of the guide rail mounting surface and the Z-axis; take several points in the interval X∈[C,1 / 2L], with equal spacing between each point, and fit a straight line B that conforms to the actual deformation trend under each selected X coordinate. XY =O X Y+P X The theoretical deformation diagram of the selected points is obtained; by fitting the trend of the theoretical deformation diagram of these selected points, the deformation of the points on the entire guide rail mounting surface is obtained, and the complete deformation is obtained only in the linear motor magnetic attraction force F. B Deformation diagram of the guide rail mounting surface under action; where O X P represents the slope of the deformation curve generated on the guide rail mounting surface in the X-axis coordinate. X The point where the deformation curve generated on the guide rail mounting surface in the X coordinate intersects with the Z axis;

[0125] Further, step S4 includes:

[0126] S41. Deformation data matching and retrieval: Retrieve the data from the standardized data file archived in step S34, specifically the data under "only subjected to beam pressure F". A "Deformation data of guide rail mounting surface under action" and "Data on magnetic attraction force F of X-axis linear motor only" B "Deformation data of guide rail mounting surface under action"; only subjected to crossbeam pressure F A The deformation data of the guide rail mounting surface under the action is A corresponding to the X coordinate. XY Value; only affected by the magnetic attraction force F of the X-axis linear motor. B The deformation data of the guide rail mounting surface under action is the B corresponding to the coordinate point (X,Y). XY value;

[0127] S42. Calculation of total deformation at a single point: For each coordinate point (X,Y) on the guide rail mounting surface 13, according to formula C... XY =A XY +B XY Calculate the total deformation C XY Among them, A XY Let the coordinate point (X,Y) be under the beam pressure F A Z-axis deformation under action; (A under the same X coordinate) XY Value uniformity; B XY The magnetic attraction force F of the linear motor at coordinate point (X,Y) on the X-axis B The Z-axis deformation under the action forms "coordinate point (X,Y) - total deformation C". XY The complete data matrix;

[0128] S43. Verification of the rationality of total deformation: Compare the C values ​​of adjacent coordinate points. XY If a sudden change in deformation occurs, backtrack the deformation data from step S3 and check A. XY Or B XY Is there an error in the calculation? Based on the strength requirements of the cable tray structure, determine the maximum C. XY If the value is within the elastic deformation range of the material, then the cable tray structure design needs to be re-optimized, and then return to step S2 to perform finite element analysis again.

[0129] S44. Set the reverse compensation amount: Based on the core objective of "counteracting total deformation", determine the compensation deformation amount for each coordinate point (X,Y) as -C. XY (i.e., with C) XY (Z-axis deformations of equal magnitude but opposite direction) ensure that the guide rail mounting surface is aligned with the actual force (F) after machining. A +F B When the deformation caused by artificial processing cancels out the deformation caused by force;

[0130] S45. Define machining tool parameters: For each coordinate point (X,Y), define the compensation deformation amount -C. XY Converted into a Z-axis offset command for the machining tool; if C XY If the value is positive (the guide rail mounting surface deforms downwards), the tool needs to be offset upwards by -C. XY (i.e., the Z-axis coordinate increases by |C) XY |); If C XY If the value is negative (the guide rail mounting surface deforms upwards), the tool needs to be offset downwards by -C. XY (i.e., the Z-axis coordinate decreases by |C) XY |);

[0131] For F B The tilting deformation of the guide rail mounting surface under the action (by B) XY linear slope (Decision), add tool tilt angle command to the programming; based on the X coordinate. Value (slope of the deformed line), calculate the tilt angle that the tool needs to be adjusted (to...). (Equal in size and opposite in direction) to ensure that the tilting trend of the guide rail mounting surface after processing cancels out the tilting trend under force, avoiding local precision deviation;

[0132] S46. Define the programming scope: Clearly define the effective scope of compensation programming as X∈[C,1 / 2L] and Y∈[0,W]. Only the actual working area of ​​the guide rail is compensated. Non-travel areas (such as the top surface 14 at both ends of the cable tray) are not included in the programming scope to reduce the amount of invalid programming work.

[0133] S47. Based on the determined Z-axis offset and tilt angle parameters, use CNC programming software (such as UG CAM, Mastercam) to write a finishing CNC program for the guide rail mounting surface 13; use CNC simulation software (such as VERICUT) to import the written program, build a virtual environment consistent with the actual machining (including bridge model, machining tools, machine tool parameters), and simulate the machining process of the guide rail mounting surface.

[0134] Check the 3D model of the guide rail mounting surface after simulation machining, measure the actual Z-axis dimension of each coordinate point (X,Y), and verify whether the deviation from the "theoretical design dimension (no deformation state)" is ≤3μm (meeting the guide rail installation accuracy requirements of the high-speed gantry machining center). If the deviation exceeds the standard, adjust the programming parameters (such as correcting the Z-axis offset and optimizing the tilt angle) until the simulation results are qualified.

[0135] S48. Perform compensation processing control: According to the processing state requirements of step S1, fix the cable tray 1 vertically on the processing machine tool, and calibrate the verticality of the cable tray (Z-axis deviation ≤ 0.02mm / m) with a level and dial indicator to ensure that the processing state is consistent with the usage state and avoid the impact of gravity deformation on the compensation effect.

[0136] Import the verified CNC program into the machine tool, select a non-core area of ​​the guide rail mounting surface 13 (such as the edge near X=C) for trial cutting, measure the Z-axis dimension of the trial cutting area, and compare the deviation between the theoretical compensation value and the actual machining value: if the deviation is ≤2μm, it means that the program matches the machining state, and full-area compensation machining can be started; if the deviation is >2μm, check the machine tool accuracy (such as tool wear) and bridge fixing rigidity (such as whether there is vibration), adjust and re-trial cutting until the deviation is acceptable;

[0137] Start the CNC program and perform full-area compensation machining on the X∈[C,1 / 2L] and Y∈[0,W] regions of the guide rail mounting surface 13. During the machining process, monitor the Z-axis coordinate feedback value of the machine tool in real time (obtained through the machine tool grating ruler) to ensure that the tool offset is consistent with the programming instructions. If the coordinate deviation exceeds the tolerance (e.g., >1μm), stop the machining immediately, troubleshoot the fault (e.g., program transmission error, tool loosening) and then continue.

[0138] S49. Perform post-processing accuracy inspection and fine-tuning. After processing, use a laser interferometer (such as Renishaw XL-80) to measure the flatness of the guide rail mounting surface 13 for preliminary accuracy inspection; if the inspection finds that the flatness deviation of a local area exceeds the standard (>5μm), retrieve the C value of that area. XY Calculate the data, analyze the causes of the deviation, adjust the compensation programming parameters for the area accordingly, and perform secondary supplementary processing. After secondary processing, check the flatness again to ensure that the error of the entire area is ≤5μm. At the same time, record the correspondence between the compensation processing parameters and the actual accuracy test results to form a process database, which will provide a reference for the compensation processing of similar cable trays in the future.

[0139] In step S4, the total deformation C of the guide rail mounting surface coordinate point (X,Y) is calculated. XY In this case, instead of considering the actual destination of the point with coordinates (X,Y) (i.e., the offset in the X and Y axes), the focus is on the offset along the Z axis, transforming a three-dimensional spatial problem into a one-dimensional linear problem, thus reducing the analysis difficulty and computational load. When some influencing factors, such as the magnitude of the magnetic attraction force and the weight of the crossbeam, change, the new total deformation graph can be quickly obtained by adjusting the parameter settings in the finite element analysis, and the corresponding compensation scheme can be output. By eliminating interference terms and performing finite element analysis, the total deformation C of the coordinate point (X,Y) on the guide rail mounting surface is obtained. XYBased on the deformation diagram, CNC programming is performed in advance to control the offset and tilt angle of the machining tool in the Z-axis direction, and a corresponding compensation deformation amount -C is machined in the Z-axis direction at the coordinate point (X,Y). XY Used to offset total deformation C XY The impact.

[0140] This invention addresses the industry pain point of controlling the precision of the X-axis guide rail mounting surface in large high-speed gantry machining center cable trays due to their height, large span, and the combined effects of welding, processing, hoisting, transportation, assembly, self-weight, beam pressure, and the magnetic attraction force of the X-axis linear motor. By covering deformation factors throughout the entire product lifecycle of the cable tray, it eliminates numerous interfering factors through specific methods such as integrated welding of the columns and base, limiting hoisting positions and thickening stiffening plates, and standardized welding processes. Furthermore, by combining finite element analysis to focus on the core stress deformation caused by beam pressure and motor magnetic attraction force, it innovatively simplifies the complex three-dimensional spatial deformation problem into a one-dimensional linear deformation problem focusing only on the Z-axis direction, significantly reducing the complexity of the deformation. This reduces the difficulty and computational load of analysis; at the same time, unlike traditional solutions that require repeated disassembly and reassembly of the entire machine or writing electrical compensation programs point by point, accuracy can be achieved simply through finite element analysis and reverse compensation machining in advance. Combined with the unified posture of vertical machining, transportation, and assembly throughout the entire process, as well as the stress elimination through simulated aging during cyclic transportation, it significantly shortens time, reduces costs, simplifies operation, and ensures accurate and reliable precision. Moreover, when factors such as the weight of the crossbeam and magnetic attraction change, only the finite element parameters need to be adjusted to quickly generate a new compensation scheme, effectively meeting the needs of large stroke, high speed, and high efficiency machining of integrated die-cast parts, improving the stability of machine tool performance and the convenience of operation and maintenance, and reducing production and maintenance risks.

[0141] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for compensating for the error of the guide rail mounting surface in a bridge structure of a high-speed gantry machining center, characterized in that, Includes the following steps: S1. Eliminate interference factors: Control welding deformation, processing deformation, hoisting deformation, transportation deformation, assembly deformation, and cable tray self-weight deformation by specifying the cable tray welding method, processing status, hoisting method, transportation fixing method, and assembly status, thereby avoiding interference; S2, Finite Element Analysis: Establish the cable tray subjected only to the crossbeam pressure F. A Only subject to the magnetic attraction force F of the X-axis linear motor B The mechanical model is defined as follows: the guide rail mounting surface is denoted as the XY plane. The coordinate system is established with the X-axis as the length direction of the cable tray, the Y-axis as the width direction of the cable tray, and the Z-axis as the height direction of the cable tray. The 0 point is the upper left corner vertex of the guide rail mounting surface in the top view of the cable tray. The X-axis coordinate is defined as the projection of the center positions of the two sliders below the crossbeam onto the X-axis. S3, deformation calculation: for the model only under the beam pressure F A , in the interval X∈[C, 1 / 2L] take equal interval points to analyze the theoretical deformation A of each point in Z axis direction XY ; the theoretical deformation of each point in Z axis direction is fitted to obtain the complete deformation diagram of the guide rail mounting surface under the action of beam pressure F A ; for the model only under the action of X axis linear motor magnetic force F B , in the interval X∈[C, 1 / 2L] take equal interval points, and take different Y coordinate points under each X coordinate to analyze the deformation B in Z axis direction XY , and the deformation line under each X coordinate is fitted to obtain the complete deformation diagram of the guide rail mounting surface under the action of X axis linear motor magnetic force F B ; S4, according to the beam pressure F A deformation A of the rail mounting surface under the action of the magnetic force F XY and X-axis linear motor B deformation B of the rail mounting surface under the action of the magnetic force F XY total deformation C of the rail mounting surface coordinate point (X, Y) XY ; the total deformation expression is: C XY = A XY +B XY ; according to the deformation graph of the total deformation C XY , numerical control programming is carried out in advance, the offset amount and the angle of inclination of the machining tool in the Z-axis direction are controlled, a corresponding compensation deformation amount -C XY in the Z-axis direction of the coordinate point (X, Y) is machined in advance, precision detection and fine adjustment are carried out after machining, and finally the deformation of the bridge rail mounting surface is greatly reduced.

2. The method for compensating for guide rail mounting surface errors in a high-speed gantry machining center bridge structure according to claim 1, characterized in that: The cable tray (1) of the cable tray structure is welded from steel plates; the machine tool column and the base are welded together; the cable tray (1) is equipped with stiffening plates (11) arranged according to topology optimization; and multiple weight reduction holes (12) are provided on the exterior. The cable tray (1) has a guide rail mounting surface (13) machined on its middle horizontal surface; At least three bosses (15) for mounting the magnetic plates of the X-axis linear motor are horizontally welded on the vertical surface above the bridge frame (1); A guide rail (2) is installed on the guide rail mounting surface (13), and a slider (21) is installed on the guide rail (2). The top of the slider (21) is connected to the crossbeam (3); the top surfaces (14) at both ends of the bridge frame are located outside the stroke of the guide rail (2); The coil (4) of the X-axis linear motor is located on the side of the crossbeam (3); the magnetic plate (5) of the X-axis linear motor is mounted on the boss (15) of the bridge frame (1).

3. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 2, characterized in that: The arrangement of the stiffening plates (11) of the cable tray (1), the location of the holes (12) for weight reduction, the location of the hoisting points, and the number and location of the bosses (15) are all determined through topology optimization and finite element analysis, so as to achieve lightweighting while meeting the strength requirements.

4. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 3, characterized in that: The stiffening plate (11) at the hoisting point of the cable tray (1) has been thickened, and the hoisting point is close to the outside of the cable tray to avoid the core area.

5. The method for compensating for the guide rail mounting surface error of the bridge structure of a high-speed gantry machining center according to any one of claims 1-4, characterized in that, Step S2 includes: S21. Based on the cable tray structure design parameters, establish a 1:1 three-dimensional geometric model of the cable tray using drawing software; S22. For different components of the cable tray, such as the main steel plate, stiffener (11), guide rail mounting surface (13), boss (15), slider (21), and guide rail (2), select the appropriate finite element mesh type; the main steel plate adopts "hexahedral mesh", and the connection part between the stiffener (11) and the main steel plate adopts "transition mesh"; the mesh density is increased in the contact projection area of ​​the guide rail mounting surface (13), boss (15), slider (21) and guide rail (2); S23. Based on the actual steel plate material used in the cable tray, query and enter the mechanical property parameters of the material, and bind the material parameters to the corresponding parts in the 3D model; S24. Establish a right-hand rectangular coordinate system with the upper left corner vertex of the guide rail mounting surface (13) in the top view of the cable tray as the origin; the X-axis is along the length of the cable tray, the Y-axis is along the width of the cable tray, and the Z-axis is along the height of the cable tray; mark the center position of the two sliders (21) below the crossbeam (3) in the coordinate system and clarify the coordinates of their projection (211) on the X-axis; at the same time, mark the boundary coordinates of the X-axis guide rail mounting surface (13) to define the analysis area; S25, the connecting surface of the bridge bottom and the base is set as "fixed constraint", simulating the fixed state of the bridge in actual use; for the mechanical model of only bearing beam pressure F A , the pressure F of the beam on the rail mounting surface (13) is calculated according to the design weight of the beam (3) A , F A is applied to the projection area of the beam (3) in contact with the rail (2) through the slider (21) in the form of "uniform load"; for the mechanical model of only bearing X-axis linear motor magnetic attraction force F B , the mutual attraction force F between the magnetic plate (5) and the coil (4) is calculated according to the design parameters of the X-axis linear motor through electromagnetic mechanics formula B , F B is applied to the top surface of the three bosses (15) in the form of "concentrated load", and the load distribution of each boss (15) is proportional to the actual stress area of the magnetic plate (5), simulating the actual effect of magnetic attraction force on the bridge. S26, start the solver of the finite element analysis software, respectively, to "only F A " and "only F B " model solution, generate the original data file containing the node Z-axis direction deformation.

6. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 5, characterized in that, Step S3 includes: S31: Based on the actual working stroke of the X-axis guide rail, the X coordinate interval for analysis is locked as [C, 1 / 2L], where C is the initial offset of the stroke and L is the total length of the cable tray. Redundant data on the top surfaces (14) at both ends of the cable tray are excluded, and only the finite element calculation results of the core working area on the guide rail mounting surface (13) are retained. S32. From the full-node data generated by the finite element analysis in step S26, extract only the deformation value of each node in the Z-axis direction to form a two-dimensional data matrix of "deformation of coordinate point (X,Y) in the Z-axis". S33. Based on the two-dimensional data matrix of "deformation of coordinate point (X,Y) on the Z-axis", perform calculations for the deformation under only beam pressure F. A The deformation at that time and the magnetic attraction force F of the X-axis linear motor only B The deformation was calculated and fitted under the beam pressure F, and the result was obtained. A Deformation diagram of the guide rail mounting surface under action and the magnetic attraction force F of the X-axis linear motor only B Deformation diagram of the guide rail mounting surface under action; S34. The fitted "only subjected to crossbeam pressure F" A The discrete data corresponding to "deformation diagram of guide rail mounting surface under action" and "only subjected to magnetic attraction force F of X-axis linear motor" are shown. B The discrete data corresponding to the "deformation diagram of the guide rail mounting surface under action" are stored as standardized data files, and the data sources are marked.

7. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 6, characterized in that, The step S33 described only as being subjected to beam pressure F A The calculation and fitting of deformation over time includes: Within the interval X∈[C,1 / 2L], based on the principle of balancing "accuracy requirements + computational efficiency", equally spaced sampling points are set, denoted as X1, X2…X. n n is the total number of sampling points for the X coordinate; For each sampling point on the X-axis, a reference point is selected in the Y-axis direction corresponding to that X-axis sampling point. The Z-axis deformation of this reference point is used to represent the deformation characteristics of all Y-axis points under that X-axis coordinate, forming a set of beam pressure analysis points (X1, Y1), (X2, Y1)...(X...). n ,Y1); The deformation values ​​in the Z-axis direction corresponding to each analysis point were read using finite element analysis software and denoted as follows: By using polynomial fitting or spline curve fitting, discrete analysis points are substituted into the fitting model to obtain the fitting curve. Based on the final fitted curve, a two-dimensional graph of "X-axis deformation - Z-axis deformation" is plotted to obtain the result under the beam pressure F alone. A Deformation diagram of the guide rail mounting surface under action.

8. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 6, characterized in that, The step S33 described is only subject to the magnetic attraction force F of the X-axis linear motor. B The calculation and fitting of deformation over time includes: Within the interval X∈[C,1 / 2L], based on the principle of balancing "accuracy requirements + computational efficiency", equally spaced sampling points are set to form a set of beam pressure analysis points X1, X2…X n ; Multiple equally spaced sampling points are selected along the Y-axis direction corresponding to each X-axis sampling point, denoted as Y1, Y2…Y… m m represents the total number of equally spaced sampling points selected along the Y-axis corresponding to a single X-coordinate sampling point; forming the X-axis linear motor magnetic attraction force analysis point set (X... n ,Y1),(X n Y2)…(X n Y m For each X-axis sampling point, read the Z-axis deformation value of all corresponding Y-axis sampling points, and record it as... Using the "least squares method" for discrete data By performing linear fitting, the equation of the deformed straight line in the X coordinate is obtained: B XY =O X Y+P X , of which O X P represents the slope of the deformation curve generated by the guide rail mounting surface in the X-axis coordinate. X Let X be the intersection point of the deformation curve generated by the guide rail mounting surface in the X coordinate and the Z axis; for all X-axis sampling points X1, X2…X in the interval X∈[C, 1 / 2L] n The corresponding deformed linear equations were obtained by fitting all of them: Form a set of lines; The slope of the deformed curve generated when the X=n coordinate is used; The intersection of the deformation curve generated when the X=n coordinate of the guide rail mounting surface and the Z-axis; Using the X-axis as the horizontal coordinate, the Y-axis as the vertical coordinate, and the Z-axis deformation as the height, the deformation lines corresponding to all X-axis sampling points are integrated. Then, using a "bilinear interpolation" or "surface fitting" algorithm, a continuous deformation surface covering the entire X∈[C, 1 / 2L] and Y∈[0, W] region is constructed; W is the width of the guide rail mounting surface. Based on the fitted surface, plot a 3D color cloud map or a 2D contour map of the "XY coordinates - Z-axis deformation" to obtain the magnetic attraction force F of the linear motor only affecting the X-axis. B Deformation diagram of the guide rail mounting surface under action.

9. The method for compensating for the guide rail mounting surface error of the bridge structure of a high-speed gantry machining center according to any one of claims 6-8, characterized in that, Step S4 includes: S41. Retrieve the data from the standardized data file archived in step S34, specifically the data under "only subjected to beam pressure F". A "Deformation data of guide rail mounting surface under action" and "only subjected to the magnetic attraction force F of X-axis linear motor" B "Deformation data of guide rail mounting surface under action"; only subjected to crossbeam pressure F A The deformation data of the guide rail mounting surface under the action is A corresponding to the X coordinate. XY Value; only affected by the magnetic attraction force F of the X-axis linear motor. B The deformation data of the guide rail mounting surface under action is the B corresponding to the coordinate point (X,Y). XY value; S42. For each coordinate point (X,Y) on the guide rail mounting surface (13), according to formula C XY =A XY +B XY Calculate the total deformation C XY Among them, A XY Let the coordinate point (X, Y) be under the beam pressure F A Z-axis deformation under action; B XY The magnetic attraction force F of the linear motor at coordinate point (X,Y) on the X-axis B Z-axis deformation under action; S43, Compare C with adjacent coordinate points XY If a sudden change in deformation occurs, backtrack the deformation data from step S3 and check A. XY Or B XY Is there an error in the calculation? Based on the strength requirements of the cable tray structure, determine the maximum C. XY If the value is within the elastic deformation range of the material, then the cable tray structure design needs to be re-optimized, and then return to step S2 to perform finite element analysis again. S44. Based on the core objective of "compensating for total deformation", determine the compensation deformation amount for each coordinate point (X,Y) as -C. XY ; S45. For each coordinate point (X,Y), the compensation deformation amount -C XY Converted into a Z-axis offset command for the machining tool; if C XY If the value is positive, the tool needs to be offset upwards by -C. XY If C XY If the value is negative, the tool needs to be offset downwards by -C. XY ; Targeting F B The tilting deformation of the guide rail mounting surface under the action is addressed by adding a tool tilt angle command to the programming; based on the X-axis... The value is used to calculate the tilt angle that the tool needs to be adjusted. S46. The effective range of compensation programming is defined as X∈[C, 1 / 2L] and Y∈[0, W]. S47. Based on the determined Z-axis offset and tilt angle parameters, use CNC programming software to write a CNC program for the finishing of the guide rail mounting surface (13); import the written program into CNC simulation software, build a virtual environment consistent with the actual machining, and simulate the machining process of the guide rail mounting surface; check the three-dimensional model of the guide rail mounting surface after simulation machining, measure the actual Z-axis dimension of each coordinate point (X,Y), and verify whether the deviation from the "theoretical design dimension" is ≤3μm. If the deviation exceeds the standard, adjust the programming parameters until the simulation result is qualified. S48. According to the processing state requirements of step S1, fix the bridge (1) vertically on the machine tool, and calibrate the verticality of the bridge using a level and dial indicator; import the verified CNC program into the machine tool, select the non-core area of ​​the guide rail mounting surface (13) for trial cutting, measure the Z-axis dimension of the trial cutting area, and compare the deviation between the theoretical compensation value and the actual processing value: if the deviation is ≤2μm, it means that the program matches the processing state, and full-area compensation processing can be started; if the deviation is >2μm, check the accuracy of the machine tool and the fixing rigidity of the bridge, adjust and re-test cut until the deviation is qualified. Start the CNC program and perform full-area compensation machining on the X∈[C,1 / 2L] and Y∈[0,W] regions of the guide rail mounting surface (13). During the machining process, monitor the Z-axis coordinate feedback value of the machine tool in real time to ensure that the tool offset is consistent with the programming instructions. If the coordinate deviation is >1μm, stop the machining immediately, troubleshoot the fault, and continue. S49. After processing, use a laser interferometer to measure the flatness of the guide rail mounting surface (13) for preliminary accuracy testing; if the test finds that the flatness deviation of a local area is >5μm, retrieve the C value of that area. XY Calculate the data, analyze the causes of the deviation, adjust the compensation programming parameters for the area accordingly, and perform secondary processing. After secondary processing, check the flatness again to ensure that the error of the entire area is ≤5μm. At the same time, record the correspondence between the compensation processing parameters and the actual accuracy test results to form a process database.

10. The method for compensating for guide rail mounting surface errors in the bridge structure of a high-speed gantry machining center according to claim 9, characterized in that, Step S1 welding deformation control includes: during the welding process, by reasonably setting the bevel of each sub-component, the lap joint method between sub-components, following a reasonable welding sequence and direction, and adding auxiliary measures, the main direction of subsequent stress release is controlled to be parallel to the X-axis guide rail mounting surface while reducing welding stress; Deformation control during hoisting includes thickening the steel plates at the hoisting points, ensuring that the actual usable portion of the guide rail mounting surface avoids the hoisting points, and setting the hoisting points on the outer side near the cable tray to avoid the core area. Assembly deformation control includes ensuring that the cable tray remains vertically fixed during assembly, consistent with actual operation. Self-weight deformation control includes welding the machine tool column and base into a single unit, which significantly reduces the height of the bridge frame and maintains vertical machining during processing, consistent with actual work. The deformation control during transportation includes: the cable tray is loaded onto the vehicle after semi-finishing. The cable tray is fixed by special tooling during loading and remains upright, consistent with its state during processing and use. After loading, it is circulated in a designated area nearby for a period of time before being unloaded for finishing. After finishing, it is circulated again, unloaded, and then the accuracy of the cable tray is calibrated and final supplementary processing is performed.

Images