Rotary table integrated cam contour curved surface high fidelity precision machining device and method

Abstract

The application discloses a turret integrated cam contour curved surface high-accuracy machining device and method, and aims at the problems of insufficient rigidity of long cylindrical integrated cam clamping, poor contour machining accuracy, no real-time monitoring in the machining process, insufficient closed-loop compensation capacity and the like in the prior art, optimizes a horizontal thermal symmetry bed structure, adopts a double-end coaxial clamping scheme, is matched with a multi-source parameter space-time synchronous real-time monitoring system, a self-adaptive hierarchical early warning machining regulation and control unit, a special cam contour process module and an online contour closed-loop detection unit, forms a full-closed-loop machining system of'machining-monitoring-regulation and control-detection-compensation', realizes cam contour degree error ≤0.003mm, surface roughness Ra ≤0.4 μm, graduation accuracy ≤±3 arc seconds, and consistency of batch machining precision for 72 hours continuously ≥99.5%, and meets the high-precision and high-consistency requirements of high-end turrets for cam parts in the fields of aerospace, precision molds, medical devices and the like, and promotes the localization substitution of high-end cam machining equipment.

Description

Technical Field

[0001] This invention relates to the field of precision bearing machining technology, specifically to a high-fidelity precision machining device and method for integrated cam profile surfaces on rotary tables. It is particularly suitable for machining core integrated cam parts of cam-type four-axis / five-axis CNC rotary tables and APC horizontal cam exchange tables, and can meet the high-precision and high-consistency machining requirements of high-end rotary tables in aerospace, precision mold, medical device and other fields for cam parts. Background Technology

[0002] The cam indexing mechanism is the core transmission component of a CNC rotary table. It achieves the conversion from high-speed, low-torque input to high-torque output through the backlash-free meshing of the cam and needle roller bearings. The machining accuracy and surface realism of the cam parts directly determine the indexing accuracy, repeatability, and operational stability of the CNC rotary table. To ensure transmission rigidity and coaxiality, high-end rotary table cams adopt an integrated design of the cam and input shaft. The workpiece is a long cylindrical structure with a complex spatial variable lead surface profile, making machining extremely difficult.

[0003] Currently, domestic cam machining mostly uses conventional five-axis machining centers, which have the following core technical defects in actual production, making it difficult to meet the machining requirements of high-precision rotary tables: 1. Insufficient clamping rigidity of long-axis workpieces and poor contour machining accuracy: Conventional five-axis machining centers are mostly vertical structures. For long cylindrical workpieces with cams and input shafts integrated, only single-end cantilever clamping can be used. During the machining process, cutting chatter and workpiece deflection are easy to occur, resulting in ripples and deviations on the cam contour surface. The machining contour has low overlap with the theoretical model and poor accuracy, which cannot meet the parameter requirements of high-precision rotary tables. 2. Lack of dedicated cam machining technology and unreasonable path planning: The CAM system of conventional machining centers does not have a dedicated machining strategy for the complex spatial contour of cams. It mostly adopts the general equal step distance machining method. The tool path has inflection points and large feed fluctuations, which not only leads to poor surface roughness, but also easily causes overcutting and undercutting problems, which seriously affects the accuracy of cam contour. 3. Lack of real-time monitoring during the machining process, and machine tools cannot maintain optimal condition for a long time: Existing machining centers lack a real-time monitoring system for all-dimensional parameters, and cannot perceive the working conditions such as machine tool thermal deformation, cutting vibration, tool wear, and workpiece temperature changes during the machining process in real time. During long-term continuous machining, the machine tool condition continues to drift, the machining accuracy gradually decreases, and the accuracy consistency of cam parts produced in batches is poor, which cannot meet the needs of large-scale production. 4. Separation of machining and inspection, and insufficient closed-loop compensation capability: Existing cam machining mostly adopts the mode of "offline machining-offline inspection-rework correction". After the workpiece is disassembled, the second clamping is prone to positioning error, the rework efficiency is low, and real-time closed-loop compensation during the machining process cannot be achieved. The machining accuracy of the cam profile surface is difficult to guarantee stably. 5. Imported equipment monopoly, high cost and poor adaptability: High-end cam machining relies on imported five-axis machining centers, with equipment costs reaching millions. Moreover, there is no dedicated process library for domestic cam rotary tables, resulting in poor adaptability, which seriously restricts the large-scale development and cost control of domestic high-end CNC rotary tables.

[0004] Existing related patent technologies have also failed to solve the above problems: CN207402173U (Cam Copying CNC Machine Tool): It only adopts the basic copying structure of single feed on the Z-axis and eccentric oscillation on the AB-axis. It lacks a horizontal thermally symmetrical bed, double-end coaxial clamping, real-time monitoring of multi-source parameters, adaptive control, dedicated cam process module, and online detection and closed-loop compensation system. It cannot meet the high realism, high precision, and batch consistency processing requirements of integrated long cylindrical cams.

[0005] US20130160619A1 (Lathe Bed Rib Structure): It only reduces thermal deformation by optimizing the spacing of the bed ribs. It lacks a dedicated cam machining structure, double-end clamping, multi-source monitoring, adaptive control, and online closed-loop compensation. It can only solve the problem of local thermal deformation of the bed and cannot be adapted to the precision machining of integrated cams.

[0006] CN115007887B (High-precision double-mountain guide rail CNC horizontal lathe boring machine): This is a general-purpose horizontal lathe boring machine. It adopts a double-mountain guide rail to improve rigidity. However, it lacks a dedicated B-axis rotary unit for cams, multi-source real-time monitoring, adaptive machining control, dedicated cam technology, and online contour detection and closed-loop compensation. Therefore, it cannot achieve high-fidelity machining of cam contour surfaces.

[0007] CN110788673A (Vertical and Horizontal Composite Machining Center): This is a general-purpose vertical and horizontal composite machine tool. It adopts a herringbone column and dual spindle structure. It lacks dedicated double-end coaxial clamping for cams, multi-source parameter monitoring, adaptive control, dedicated cam machining strategy, and online closed-loop compensation. It does not have the capability for integrated cam precision machining.

[0008] CN120287056A (Composite Horizontal Machining Center): It adopts a T-shaped bed + internal and external dual spindle structure to realize the combination of milling and turning. However, it lacks cam-specific double-end clamping, multi-source real-time monitoring, adaptive threshold control, dedicated cam residual height path, and online detection closed-loop compensation, which cannot meet the high-fidelity machining requirements of cam profile.

[0009] In summary, existing technologies cannot simultaneously solve the core problems of insufficient clamping rigidity of long-axis cams, poor contour accuracy, machining accuracy drift, low batch consistency, and lack of closed-loop compensation. High-end cam machining relies on imported equipment, which is costly and has poor adaptability, thus restricting the development of the domestic high-end CNC rotary table industry. Summary of the Invention

[0010] The purpose of this invention is to provide a high-fidelity precision machining device and method for integrated rotary table cam profile surfaces, aiming to solve the following core defects in existing cam machining technologies: Conventional five-axis machining centers lack sufficient clamping rigidity for long cylindrical integrated cams, easily causing chatter and tool deflection, resulting in poor fidelity and low precision in cam profile surface machining; lack of dedicated cam machining processes leads to unreasonable toolpath planning, large feed fluctuations, and problems such as overcutting, undercutting, and poor surface quality; lack of a real-time monitoring system for all-dimensional machining parameters makes it impossible to perceive changes in machine tool conditions in real time, making it difficult to maintain optimal machining conditions for extended periods, resulting in poor consistency in batch machining; separation of machining and inspection, lack of online closed-loop compensation mechanisms, low rework efficiency, and difficulty in consistently guaranteeing profile accuracy; high cost and poor adaptability of imported equipment, and insufficient core technologies in domestically produced cam machining equipment.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A high-fidelity precision machining device for cam profile surfaces integrated with a rotary table includes a horizontal bed body, a five-axis linkage CNC system, a spindle machining unit, a B-axis rotary feed unit, a tailstock center support unit, a multi-source parameter spatiotemporal synchronous real-time monitoring system, an adaptive graded early warning machining control unit, a dedicated cam profile process module, and an online profile closed-loop detection unit. The main body of the horizontal bed is integrally cast from HT300 gray cast iron, and has a completely symmetrical and thermally symmetrical structure. It is equipped with constant temperature cooling oil channels inside, and distributed temperature sensors are arranged on the guide rail surface. The static stiffness is ≥180N / μm and the dynamic stiffness is ≥120N / μm; it is used to suppress machining vibration and thermal deformation.

[0012] The spindle machining unit is mounted on the X-axis / Z-axis bidirectional feed slide and adopts a built-in high-speed precision electric spindle with a radial runout of ≤0.001mm. The B-axis rotary feed unit and the tailstock center support unit are coaxially arranged opposite each other on the Y-axis feed worktable of the horizontal bed body. The coaxiality between the two is ≤0.002mm, and they are equipped with double-end coaxial hydraulic clamping. The multi-source parameter spatiotemporal synchronous real-time monitoring system has a maximum sampling frequency of ≥20kHz and adopts the IEEE1588 precision time protocol to achieve a spatiotemporal synchronization error of ≤1ms for multi-source data. It synchronously collects parameters across all dimensions, including spindle vibration, temperature, guideway temperature and displacement, cutting force, tool wear, workpiece runout, workpiece temperature, and ambient temperature and humidity. Specifically, it assigns a unified system clock to all acquisition nodes, with a clock synchronization error of ≤0.1ms; sets a unified hardware trigger signal based on the highest sampling frequency; and uses linear interpolation to upscale low-frequency sensors. All data is aligned with a unified timestamp to ensure accurate matching between monitoring data and processing time. The adaptive hierarchical early warning machining control unit has a built-in first-level control + second-level alarm threshold model. Combined with fuzzy PID and LM optimization algorithms, it dynamically adjusts the spindle speed, feed rate, and depth of cut and performs error compensation. The dedicated cam contouring process module incorporates a constant residual height variable feed strategy and a NURBS curve toolpath smoothing algorithm. The residual height between adjacent toolpaths is ≤0.002mm, and the feed rate fluctuation rate is ≤5%. The constant residual height variable feed strategy specifically involves extracting the curvature distribution of the cam surface, using the residual height as a constraint, reducing the line spacing and feed rate in areas with high curvature, and increasing the line spacing and feed rate in areas with low curvature. The NURBS smoothing algorithm uses cubic non-uniform rational B-splines to fit the tool position point, controlling the fitting deviation to ≤0.001mm, and eliminating sharp corners in the path. The online contour closed-loop detection unit adopts a spindle-mounted high-precision probe to achieve full contour scanning and deviation compensation without disassembling the part, forming an integrated closed loop of machining-inspection-compensation. The five-axis linkage CNC system coordinates the operation of each unit to complete the precision machining of the integrated cam throughout the entire process.

[0013] In a preferred embodiment, the X-axis, Y-axis, and Z-axis feed guides in the X-axis / Z-axis bidirectional feed slide and the Y-axis feed worktable are all roller linear guides to ensure motion accuracy and load-bearing capacity.

[0014] In a preferred embodiment, the spindle machining unit has a rated power of ≥15kW and a maximum speed of ≥12000rpm. The front end of the spindle is equipped with a three-axis MEMS vibration sensor, an infrared temperature sensor, and a radial runout detection module for real-time monitoring of the spindle's operating status.

[0015] In a preferred embodiment, the B-axis rotary feed unit incorporates a high-precision double-lead worm gear pair with an indexing accuracy of ≤ ±5 arcseconds and a repeatability of ≤ ±2 arcseconds. The output end is equipped with a three-jaw hydraulic chuck. The tailstock center support unit is equipped with a Morse No. 5 hydraulic telescopic center with a telescopic stroke ≥ 150mm and an adjustable clamping force range of 500-3000N, suitable for long cylindrical integrated cam workpieces with a length of 200-1200mm and a diameter of 30-100mm.

[0016] In a preferred embodiment, the threshold values ​​of the adaptive graded early warning machining control unit are as follows: when the vibration amplitude is ≥2g, the feed and depth of cut are reduced; when the spindle temperature rise is ≥8℃, thermal error compensation is triggered; when the tool wear is ≥0.002mm, the tool length and radius are compensated; the secondary alarm threshold is 1.5 times the primary threshold, and the machine tool automatically stops as a warning when triggered.

[0017] In a preferred embodiment, the dedicated cam profile process module has a built-in cam profile design database, which directly imports theoretical models and automatically matches them with the machining process library.

[0018] In a preferred embodiment, the online contour closed-loop detection unit is a trigger-type or laser scanning probe with a repeatability accuracy of ≤0.001mm.

[0019] In one preferred embodiment, the cam profile error after machining is ≤0.003mm, the surface roughness Ra is ≤0.4μm, the indexing accuracy is ≤±3 arcseconds, and the consistency of batch machining accuracy is ≥99.5% after 72 hours of continuous processing.

[0020] This application also provides a high-fidelity precision machining method for an integrated rotary table cam profile surface, including the following steps: S1, Simultaneous clamping at both ends and machine initialization: The drive end of the long cylindrical workpiece, which integrates the cam and the input shaft, is clamped in the hydraulic chuck of the B-axis rotary feed unit. The hydraulic center of the tailstock center support unit presses against the other end of the workpiece, completing the coaxial clamping at both ends. The coaxiality of the B-axis and the tailstock center is calibrated to ≤0.002mm. The machine completes zeroing, spindle preheating, and accuracy calibration of each axis. S2, Cam Model Import and Dedicated Path Planning: Import the theoretical profile design model of the cam into the dedicated cam profile process module, match the machining process library of the corresponding cam model, generate a machining path with equal residual height and variable feed, complete the tool path smoothing through NURBS curves, and generate a CNC machining program. S3, Multi-source parameter real-time monitoring and adaptive machining: When the machining program is started, the spindle machining unit drives the milling cutter to complete the roughing, semi-finishing and finishing of the cam profile; during the machining process, the multi-source parameter spatiotemporal synchronous real-time monitoring system synchronously collects the parameters of the machine tool, cutting tool and workpiece in all dimensions, and the adaptive hierarchical early warning machining control unit analyzes the data in real time and dynamically adjusts the spindle speed, feed rate, cutting depth and error compensation value. S4, In-machine online contour inspection: After a single process is completed, the spindle is replaced with the probe of the online contour closed-loop inspection unit to perform full-range scanning inspection of the cam contour surface, compare the measured contour with the theoretical model, and calculate the contour deviation value. S5, Closed-loop compensation and finished product machining: Based on the contour deviation value, a tool path compensation program is generated, and the area with excessive deviation is finely compensated and machined. The process is then checked again until the contour accuracy meets the design requirements. After the entire process is completed, the workpiece is unloaded, and the high-fidelity precision machining of the integrated cam is completed.

[0021] In a preferred embodiment, in step S3, the roughing speed is 6000-10000 rpm, the feed rate is 1200-1800 mm / min, and the depth of cut is 0.3-0.8 mm; the finishing speed is 12000-15000 rpm, the feed rate is 600-1000 mm / min, and the depth of cut is 0.01-0.05 mm; in step S4, the number of scanning sampling points is not less than 10000 points; and in step S5, the compensation feed rate is 50%-80% of that in the finishing process.

[0022] Due to the application of the above technical solution, the beneficial effects of this application compared with the prior art are as follows: 1. The clamping rigidity and machine tool stability have been greatly improved, and the contour machining accuracy has achieved a breakthrough of orders of magnitude.

[0023] With its horizontal double-ended coaxial clamping structure, the clamping rigidity of long-axis workpieces is increased by more than 300%, completely solving the problems of machining chatter and tool deformation. Combined with a high-rigidity thermally symmetrical bed, the cam profile error after machining is ≤0.003mm, the surface roughness Ra≤0.4μm, and the indexing accuracy ≤±3 arcseconds. Compared with conventional five-axis machining centers, the profile accuracy is improved by more than 80%, fully meeting the machining requirements of high-precision cam rotary tables.

[0024] 2. Real-time monitoring and adaptive control under all working conditions ensure excellent long-term processing stability and batch consistency.

[0025] The multi-source parameter spatiotemporal synchronous real-time monitoring system realizes the synchronous acquisition of processing data in all dimensions. Combined with the adaptive hierarchical early warning processing control unit, it can dynamically optimize processing parameters in real time, suppress the accuracy drift caused by machine tool thermal deformation, vibration and tool wear. The batch processing accuracy consistency is ≥99.5% for 72 consecutive hours. Compared with the existing technology, the batch processing defect rate is reduced by more than 90%, which fully meets the needs of large-scale production.

[0026] 3. Specialized cam machining technology significantly improves the realism of contour surface machining.

[0027] A specialized machining strategy for complex cam spatial contours achieves equal residual height machining and smooth tool path, fundamentally solving the problems of overcutting, undercutting, and abrupt feed changes in general machining methods. The overlap between the machined cam contour surface and the theoretical design model is ≥99.8%, significantly improving the contour realism. With the addition of a rotary table, the rotary table indexing accuracy can be stably controlled within ±5 arcseconds.

[0028] 4. The integrated closed loop of processing, testing and compensation greatly improves processing efficiency.

[0029] The online contour closed-loop detection unit realizes on-machine full contour detection and real-time compensation, eliminating the need for offline detection and secondary clamping. The processing cycle of a single cam is shortened from the traditional 8 hours to 3 hours, the processing efficiency is increased by more than 160%, and the rework rate is reduced from 30% to less than 0.5%, significantly reducing production and manufacturing costs.

[0030] 5. Domestically produced and controllable, with strong adaptability and significant cost advantages.

[0031] This invention is based on the optimization and upgrade of Gutian Company's self-developed cam machining center, which is fully adapted to the full range of cam machining needs of domestic cam rotary tables. The equipment cost is only 30% of that of imported similar machining centers. It can break the monopoly of foreign brands in the field of high-end cam machining, promote the independent control of the entire industrial chain of domestic high-end CNC rotary tables, and has extremely high industrial value and economic benefits. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the overall structure of the high-fidelity precision machining device for the integrated rotary table cam profile surface of the present invention. Figure 2This is a flowchart of the precision machining method for the integrated cam profile surface of the rotary table according to the present invention; The components include: 1. Horizontal bed body; 2. Five-axis linkage CNC system; 3. Spindle machining unit; 4. B-axis rotary feed unit; 5. Tailstock center support unit; 6. Multi-source parameter spatiotemporal synchronous real-time monitoring system; 7. Adaptive graded early warning machining control unit; 8. Dedicated cam profile process module; 9. Online profile closed-loop detection unit. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0037] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0038] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] Please see the appendix Figure 1 and Figure 2 To make the technical solution and advantages of the present invention clearer, the present invention will be described in detail below with reference to three sets of integrated cam processing embodiments of different specifications. The performance tests all adopt the same standard testing methods and equipment.

[0041] Unified testing standards and equipment: Contour accuracy inspection: Zeiss CONTURAG3 coordinate measuring machine, measurement accuracy ≤0.0005mm; Surface roughness inspection: Malvern MSR200 roughness tester was used, with an inspection accuracy of ≤0.001μm; Indexing accuracy testing: Using a Renishaw XL-80 laser interferometer, the angular measurement accuracy is ≤0.1 arcseconds; Vibration and temperature detection: Bruker V800 vibration analyzer and Fluke PT100 temperature calibrator were used. Batch consistency inspection: After 72 hours of continuous processing, 50 pieces are sampled for accuracy inspection, and batch deviation is calculated.

[0042] Example 1 This embodiment provides a high-fidelity precision machining device and method for an integrated cam profile surface of a rotary table, used for machining arc-shaped cams for a 200-type five-axis cam rotary table.

[0043] Machining object: Arc cam for Gutian 200 AC five-axis rotary table. The cam and input shaft are integrated. The total length of the workpiece is 420mm, the diameter of the input shaft is 40mm, the maximum outer diameter of the cam is 80mm, and the profile is a variable lead spatial arc surface. Design requirements: profile error ≤0.005mm, indexing accuracy ≤±5 arcseconds, surface roughness Ra≤0.5μm.

[0044] Processing equipment configuration: Horizontal bed body 1: HT300 gray cast iron material, cross-shaped reinforcing ribs, constant temperature cooling oil channels, static stiffness 190N / μm, dynamic stiffness 130N / μm; B-axis rotary feed unit 4: double-lead worm gear pair, indexing accuracy ±4 arcseconds, three-jaw hydraulic chuck; Tailstock tip support unit 5: Morse No. 5 hydraulic telescopic tip, clamping force 1500N, telescopic stroke 180mm; Spindle machining unit 3: 18kW high-speed electric spindle, maximum speed 15000rpm, radial runout 0.0008mm; Multi-source parameter spatiotemporal synchronization real-time monitoring system 6: maximum sampling frequency 25kHz, multi-source data synchronization error 0.8ms; The specific implementation method of multi-source data spatiotemporal synchronization is as follows: The IEEE 1588 precise time protocol is adopted to allocate a unified system clock to all acquisition nodes of the data acquisition module, achieving time base synchronization of each node with a clock synchronization error ≤0.1ms; for sensors with different sampling frequencies, a unified hardware clock trigger signal is used, and the sampling trigger time of each sensor is set as an integer multiple of the highest sampling frequency to ensure time synchronization during the sampling process; the acquired multi-source data is aligned according to a unified timestamp, and low sampling frequency data is upsampled using linear interpolation to ensure that the time dimension of all data remains consistent, ultimately achieving a multi-source data spatiotemporal synchronization error ≤1ms. Adaptive hierarchical early warning processing control unit 7: an early warning model with built-in LM optimization algorithm; The machining status early warning model adopts a threshold-based hierarchical early warning model. Specifically, it presets primary and secondary alarm thresholds for each monitored parameter. The primary early warning threshold is the trigger threshold for vibration ≥2g, temperature rise ≥8℃, and tool wear ≥0.002mm. The secondary alarm threshold is 1.5 times the primary early warning threshold. Multi-source parameter data is collected in real time. When a parameter reaches the primary early warning threshold, adaptive adjustment of the corresponding parameter is triggered. When a parameter reaches the secondary alarm threshold, a machine tool shutdown warning is triggered to prevent machining failure. The parameter optimization algorithm uses a fuzzy PID control algorithm. The input is the deviation between the measured parameter value and the preset threshold, and the rate of change of the deviation. The output is the adjustment of spindle speed, feed rate, and depth of cut. Through a preset fuzzy control rule table, the optimal parameter adjustment value is output, achieving adaptive dynamic optimization of machining parameters. Dedicated Cam Contour Process Module 8: Equal Residual Height Variable Feed Machining Strategy, Curved Tool Path Smoothing Algorithm; The specific adaptation process of the variable feed machining strategy with constant residual height for cam machining is as follows: Import the 3D model of the theoretical profile of the cam and extract the feature lines and curvature distribution of the cam surface; with a preset residual height ≤ 0.002mm as a constraint, dynamically adjust the line spacing of adjacent toolpaths according to the surface curvature, reducing the line spacing in areas with large curvature and increasing the line spacing in areas with small curvature; at the same time, dynamically adjust the feed rate according to the surface curvature and the toolpath line spacing, reducing the feed rate in areas with abrupt curvature changes and increasing the feed rate in areas with gentle curvature changes, thus achieving variable feed machining; The specific implementation process of the NURBS curve toolpath smoothing algorithm is as follows: extract the tool position coordinates of the initial machining path, fit the tool position with a cubic non-uniform rational B-spline curve, smooth the sharp corners in the path, control the fitting deviation ≤0.001mm during the fitting process to ensure the overlap between the smoothed path and the theoretical contour, and at the same time make the feed rate fluctuation rate ≤5% to avoid contour deviation caused by sudden feed changes. Online contour closed-loop detection unit 9: Trigger-type probe, repeatability 0.0009mm; Five-axis linkage CNC system 2: Huazhong 8 type five-axis linkage CNC system.

[0045] Processing method: S1, simultaneous clamping at both ends and machine tool initialization.

[0046] The input shaft drive end of the integrated cam workpiece is clamped in the B-axis three-jaw hydraulic chuck, and the tailstock hydraulic center is pressed against the center hole at the other end of the workpiece. The coaxiality between the B-axis and the tailstock center is calibrated to 0.0015mm using a laser interferometer. The machine tool completes the zeroing of each axis, the spindle is preheated for 30 minutes, and the positioning accuracy of each axis is calibrated using a laser interferometer.

[0047] S2, Cam Model Import and Dedicated Path Planning.

[0048] Import the 3D model of the theoretical cam profile into the dedicated cam profile process module 8, match it with the 200-type arc cam machining process library, select a φ12mm carbide forming milling cutter, generate a machining path with constant residual height and variable feed, and the residual height of adjacent toolpaths is 0.002mm; smooth the toolpath through NURBS curves, control the feed rate fluctuation rate within 3%, and generate roughing, semi-finishing, and finishing CNC machining programs.

[0049] S3, real-time monitoring of multi-source parameters and adaptive processing.

[0050] Rough machining: spindle speed 8000rpm, feed rate 1500mm / min, depth of cut 0.5mm, removing most of the blank allowance; Semi-finishing: Spindle speed 10000rpm, feed rate 1000mm / min, depth of cut 0.1mm, with a finishing allowance of 0.03mm; Finishing: Spindle speed 15000rpm, feed rate 800mm / min, depth of cut 0.03mm; During machining, the multi-source parameter spatiotemporal synchronous real-time monitoring system 6 synchronously collects spindle vibration (25kHz), spindle temperature (1kHz), guideway temperature (1kHz), cutting force (5kHz), and workpiece radial runout (5kHz) data; The adaptive graded early warning machining control unit 7 analyzes the data in real time. When the spindle vibration amplitude reaches 2.1g, the feed rate is automatically reduced by 30%; when the spindle temperature rises to 7℃, thermal error compensation is automatically triggered, correcting the Z-axis feed coordinate by 0.001mm; when the tool wear reaches 0.002mm, the tool radius value is automatically compensated by 0.002mm.

[0051] S4, In-machine online contour detection.

[0052] After finishing, the spindle automatically changes the trigger probe to perform a full-range scan and detection of the cam profile surface, collecting 12,000 profile measurement points and generating measured point cloud data; the five-axis linkage CNC system 2 compares the measured point cloud with the theoretical model and calculates that the maximum profile deviation is 0.004mm, and the deviation in some areas exceeds 0.003mm.

[0053] S5, closed-loop compensation and finished product processing.

[0054] The local fine-tuning compensation program is automatically generated based on the contour deviation value, and secondary fine-tuning is performed on the areas where the deviation exceeds the standard. After the fine-tuning is completed, it is inspected again, and the maximum contour error is 0.0028mm, which meets the design requirements. After the workpiece is cut, it is verified by offline inspection.

[0055] Processing results: Contour accuracy error: 0.0028mm (≤0.003mm); Surface roughness: Ra = 0.32 μm (≤ 0.4 μm); Grading accuracy: ±2.8 arcseconds (≤±3 arcseconds); Consistency of batch processing accuracy over 72 consecutive hours: 99.6%; Processing cycle: 2.8 hours / piece (8 hours / piece for traditional process).

[0056] Example 2 This embodiment provides a high-fidelity precision machining device and method for an integrated cam profile surface on a rotary table, used for machining a planar cam for a 320-type heavy-duty four-axis rotary table.

[0057] Machining object: Planar cam for Gutian 320 heavy-duty four-axis rotary table, one-piece structure, total workpiece length 600mm, input shaft diameter 50mm, maximum outer diameter of cam 120mm, design requirements: contour error ≤0.004mm, surface roughness Ra≤0.4μm.

[0058] Core process and equipment parameters: Double-end clamping: B-axis clamping force 2000N, tailstock clamping force 2500N, coaxiality 0.0018mm; Dedicated process module: Adapts to the same residual height path of the planar cam, with a residual height of 0.0018mm between adjacent toolpaths; Online inspection: Laser scanning probe, scanning speed 5mm / s, sampling points 15000.

[0059] Processing results: Contour accuracy error: 0.0032mm; Surface roughness: Ra = 0.35 μm; Indexing accuracy: ±3.0 arcseconds; Batch processing consistency: 99.5%; Verification conclusion: Double-end clamping effectively suppresses chatter during heavy-load machining, and specialized processes and online detection ensure the accuracy of the planar cam profile.

[0060] Example 3 This embodiment provides a high-fidelity precision machining device and method for an integrated rotary table cam profile surface, used for machining end face cams for 400-type APC exchange tables.

[0061] Machining object: end face cam for Gutian 400 type APC horizontal exchange table, one-piece structure, total workpiece length 800mm, input shaft diameter 60mm, maximum outer diameter of cam 150mm, design requirements: contour error ≤0.003mm, accuracy decay ≤0.0005mm after 72 hours of continuous operation.

[0062] Core process and equipment parameters: Multi-source monitoring: Added cutting force sensor (sampling frequency 20kHz) and ambient temperature and humidity sensor; Adaptive control: The thermal error compensation algorithm is optimized for long-term processing, and it is automatically calibrated once per hour; Batch processing: Process 50 pieces continuously for 72 hours, with real-time monitoring and adjustment of processing parameters.

[0063] Processing results: Contour accuracy error: 0.0029mm; Surface roughness: Ra = 0.30 μm; Grading accuracy: ±2.5 arcseconds; Accuracy decay over 72 hours: 0.0004mm; Batch processing consistency: 99.7%; Verification conclusion: Multi-source monitoring and adaptive control effectively solve the problem of long-term machining accuracy drift and meet the needs of mass production.

[0064] Comparative Example: Conventional five-axis machining center processing (existing technology)

[0065] Using a vertical five-axis machining center, single-end cantilever clamping, and general machining processes, without real-time monitoring or online inspection, a 200-type arc-shaped cam of the same specification was machined. The results are as follows: Testing items Example 1 Comparative Example Increase Contour error 0.0028mm 0.015mm 81.3% Surface roughness Ra=0.32μm Ra=1.2μm 73.3% Indexing accuracy ±2.8 arc seconds ±12 arc seconds 76.7% Processing cycle 2.8 hours 8 hours 65% Batch Consistency 99.6% 85% 17.2% rework rate 0.4% 30% 98.7%

[0066] Comparative analysis: Through full-chain technological innovation, this invention far surpasses conventional processing technology in terms of contour accuracy, processing efficiency, and batch consistency, completely solving the core pain points of existing technologies and achieving remarkable technical results.

[0067] This invention addresses the pain points in machining long cylindrical integrated cams. Based on Gutian Company's self-developed cam machining center, it completely solves the core problems of poor cam profile machining accuracy, insufficient clamping rigidity, unstable long-term machining conditions, and poor batch consistency in existing technologies through a full-chain technological innovation including machine tool structure optimization, multi-source real-time monitoring, adaptive machining control, dedicated process planning, and online closed-loop compensation. The cam parts machined by this invention achieve internationally advanced levels in precision, surface quality, and consistency. The equipment cost is far lower than imported equipment, and it is fully compatible with the machining needs of Gutian's full range of cam rotary tables. This enables the localization and independent control of high-end cam machining equipment, promotes the high-quality development of the domestic high-end CNC rotary table industry, and possesses extremely high technological value and promising industrial application prospects.

[0068] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-fidelity precision machining device for an integrated rotary table cam profile surface, characterized in that, It includes a horizontal bed body, a five-axis linkage CNC system, a spindle machining unit, a B-axis rotary feed unit, a tailstock center support unit, a multi-source parameter spatiotemporal synchronous real-time monitoring system, an adaptive graded early warning machining control unit, a dedicated cam profile process module, and an online profile closed-loop detection unit. The main body of the horizontal bed is integrally cast from HT300 gray cast iron. It has a completely symmetrical and thermally symmetrical structure, and is equipped with constant temperature cooling oil channels inside. Distributed temperature sensors are arranged on the guide rail surface. The static stiffness is ≥180N / μm and the dynamic stiffness is ≥120N / μm. The spindle machining unit is mounted on the X-axis / Z-axis bidirectional feed slide and adopts a built-in high-speed precision electric spindle with a radial runout of ≤0.001mm. The B-axis rotary feed unit and the tailstock center support unit are coaxially arranged opposite each other on the Y-axis feed worktable of the horizontal bed body. The coaxiality between the two is ≤0.002mm, and they are equipped with double-end coaxial hydraulic clamping. The multi-source parameter spatiotemporal synchronization real-time monitoring system has a maximum sampling frequency of ≥20kHz and adopts the IEEE1588 precision time protocol to achieve a spatiotemporal synchronization error of ≤1ms for multi-source data. It synchronously collects parameters in all dimensions, including spindle vibration, temperature, guide rail temperature and displacement, cutting force, tool wear, workpiece runout, workpiece temperature, and ambient temperature and humidity. The adaptive hierarchical early warning machining control unit has a built-in first-level control + second-level alarm threshold model. Combined with fuzzy PID and LM optimization algorithms, it dynamically adjusts the spindle speed, feed rate, and depth of cut and performs error compensation. The dedicated cam profile process module incorporates a constant residual height variable feed strategy and a NURBS curve toolpath smoothing algorithm, ensuring that the residual height between adjacent toolpaths is ≤0.002mm and the feed rate fluctuation rate is ≤5%. The online contour closed-loop detection unit adopts a spindle-mounted high-precision probe to achieve full contour scanning and deviation compensation without disassembling the part, forming an integrated closed loop of machining-inspection-compensation. The five-axis linkage CNC system coordinates the operation of each unit to complete the precision machining of the integrated cam throughout the entire process.

2. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The X-axis, Y-axis, and Z-axis feed guides in the X-axis / Z-axis bidirectional feed slide and the Y-axis feed worktable are all roller linear guides.

3. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The spindle machining unit has a rated power of ≥15kW and a maximum speed of ≥12000rpm. The front end of the spindle is equipped with a three-axis MEMS vibration sensor, an infrared temperature sensor, and a radial runout detection module.

4. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The B-axis rotary feed unit has a built-in high-precision double-lead worm gear pair with an indexing accuracy of ≤ ±5 arcseconds and a repeatability of ≤ ±2 arcseconds. The output end is equipped with a three-jaw hydraulic chuck. The tailstock center support unit is equipped with a Morse No. 5 hydraulic telescopic center with a telescopic stroke of ≥150mm and an adjustable clamping force range of 500-3000N.

5. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The threshold values ​​of the adaptive graded early warning machining control unit are: reduce feed and depth of cut when vibration amplitude is ≥2g; trigger thermal error compensation when spindle temperature rise is ≥8℃; and compensate tool length and radius when tool wear is ≥0.002mm.

6. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The dedicated cam profile process module has a built-in cam profile design database, which can directly import theoretical models and automatically match the machining process library.

7. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, The online contour closed-loop detection unit is a trigger-type or laser scanning probe with a repeatability accuracy of ≤0.001mm.

8. The high-fidelity precision machining device for the integrated rotary table cam profile surface according to claim 1, characterized in that, After machining, the cam profile error is ≤0.003mm, the surface roughness Ra is ≤0.4μm, the indexing accuracy is ≤±3 arcseconds, and the batch machining accuracy consistency is ≥99.5% after 72 hours of continuous batch machining.

9. A high-fidelity precision machining method for an integrated rotary table cam profile surface, characterized in that, Based on the apparatus according to any one of claims 1-8, the method includes the following steps: S1, Simultaneous clamping at both ends and machine initialization: The drive end of the long cylindrical workpiece, which integrates the cam and the input shaft, is clamped in the hydraulic chuck of the B-axis rotary feed unit. The hydraulic center of the tailstock center support unit presses against the other end of the workpiece, completing the coaxial clamping at both ends. The coaxiality of the B-axis and the tailstock center is calibrated to ≤0.002mm. The machine completes zeroing, spindle preheating, and accuracy calibration of each axis. S2, Cam Model Import and Dedicated Path Planning: Import the theoretical profile design model of the cam into the dedicated cam profile process module, match the machining process library of the corresponding cam model, generate a machining path with equal residual height and variable feed, complete the tool path smoothing through NURBS curves, and generate a CNC machining program. S3, Multi-source parameter real-time monitoring and adaptive machining: When the machining program is started, the spindle machining unit drives the milling cutter to complete the roughing, semi-finishing and finishing of the cam profile; during the machining process, the multi-source parameter spatiotemporal synchronous real-time monitoring system synchronously collects the parameters of the machine tool, cutting tool and workpiece in all dimensions, and the adaptive hierarchical early warning machining control unit analyzes the data in real time and dynamically adjusts the spindle speed, feed rate, cutting depth and error compensation value. S4, In-machine online contour inspection: After a single process is completed, the spindle is replaced with the probe of the online contour closed-loop inspection unit to perform full-range scanning inspection of the cam contour surface, compare the measured contour with the theoretical model, and calculate the contour deviation value. S5, Closed-loop compensation and finished product machining: Based on the contour deviation value, a tool path compensation program is generated, and the area with excessive deviation is finely compensated and machined. The process is then checked again until the contour accuracy meets the design requirements. After the entire process is completed, the workpiece is unloaded, and the high-fidelity precision machining of the integrated cam is completed.

10. The high-fidelity precision machining method for the integrated cam profile surface of a rotary table according to claim 9, characterized in that, In step S3, the roughing speed is 6000-10000 rpm, the feed rate is 1200-1800 mm / min, and the depth of cut is 0.3-0.8 mm; the finishing speed is 12000-15000 rpm, the feed rate is 600-1000 mm / min, and the depth of cut is 0.01-0.05 mm; in step S4, the number of scanning sampling points is not less than 10000 points; in step S5, the compensation feed rate is 50%-80% of that of the finishing process.

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