Titanium alloy slide rail rough-fine cooperative processing method and system

Abstract

This invention discloses a method and system for rough and finish machining of titanium alloy slide rails, belonging to the field of intelligent machining. The method includes: after clamping and alignment, rough machining begins, with the temperature of the cutting zone controlled by a constant-temperature cutting fluid. The machining area is divided into a high-rigidity region and a low-rigidity thin-walled region, which are machined using high-feed-rate cutting and plunge milling methods, respectively. After rough machining, the actual geometric dimensions of key features of the workpiece are measured in-situ. The central control system compares the measured data with the theoretical model to generate a compensated machining path. During finish machining, either the compensated machining path or the theoretical machining path is selected and invoked, and a five-axis swing-angle avoidance machining is used for thin-walled areas. After completion, the workpiece is automatically transferred between processes using an RGV transport system, maintaining a clamped state throughout the transport process until all processes are completed. This method achieves efficient and low-deformation machining of titanium alloy slide rails and can be applied to the batch precision machining of aircraft titanium alloy slide rail parts.

Description

Technical Field

[0001] This application relates to the field of intelligent machining technology, specifically to a method and system for rough and fine machining of titanium alloy slide rails. Background Technology

[0002] Titanium alloy slide rails are crucial components of key moving parts such as aircraft wings and flaps, and their machining quality directly affects flight safety. The machining of titanium alloy slide rails presents the following technical challenges: Titanium alloys have high tensile strength but poor thermal conductivity, leading to severe tool wear and work hardening during machining, resulting in low efficiency with traditional machining methods. Aircraft guide rails are often slender and irregularly shaped, with thin lugs and deep grooves. When machined using traditional three-axis machine tools, these thin-walled sections are prone to chatter and deformation, making it difficult to guarantee dimensional accuracy. The rack grooves on the side of the guide rail are arc-shaped grooves with normal ribs perpendicular to the arc surface. This complex structure places extremely high demands on the multi-axis linkage capability and toolpath planning of the machining equipment. Traditional machining methods often employ single-machine operation, requiring multiple clamping and positioning of the workpiece during transfer between different processes, resulting in large cumulative errors, low consistency and automation in batch production, and difficulty in achieving stable and efficient batch production. Furthermore, the impact of cutting heat on the deformation of thin-walled sections during titanium alloy machining cannot be ignored. If the large amount of cutting heat generated during rough machining is not effectively controlled, it will lead to thermal deformation of the workpiece, thus affecting the final machining accuracy. Simultaneously, a certain amount of residual stress release deformation has already occurred in the thin-walled sections after rough machining; if directly proceeding to finish machining, it is difficult to guarantee the final contour accuracy of the guide rail.

[0003] Therefore, there is an urgent need to develop a method for the coordinated control of the entire process of titanium alloy slide rails from roughing to finishing. This method should combine flexible production line flow, in-situ measurement feedback and dynamic tool path compensation to achieve efficient, low-deformation and high-precision machining of titanium alloy slide rails. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a method and system for the coordinated roughing and finishing of titanium alloy slide rails. Through a collaborative closed loop of roughing thermo-mechanical control, in-situ detection and sensing, and finishing compensation execution, efficient and low-deformation machining of titanium alloy slide rails is achieved. This method can be widely applied to the batch precision machining of aircraft titanium alloy slide rail parts.

[0005] In a first aspect, the present invention provides a method for coordinating roughing and finishing of titanium alloy slide rails, based on a flexible production line comprising multiple five-axis gantry milling machines, an RGV transport system, and a central control system, comprising the following steps: Step 1: Install the titanium alloy slide rail blank onto the buffer tray and complete the alignment; Step 2: The central control system sends a start command to the five-axis gantry milling machine to begin rough machining. During rough machining, the machining area is continuously flushed with constant-temperature cutting fluid through the fluid supply system to keep the temperature of the cutting area within the predetermined temperature range. At the same time, the central control system divides the machining area into high-rigidity areas and low-rigidity thin-walled areas according to the rigidity differences of various parts of the slide rail blank. High-rigidity areas are machined with a large feed rate, while low-rigidity thin-walled areas are machined with plunge milling. The radial cutting force of plunge milling is less than that of high-feed rate cutting. Step 3: After rough machining is completed, measure the actual geometric dimensions of the key features of the workpiece and feed the measurement data back to the central control system in real time; Step 4: The central control system compares the measurement data with the theoretical model and generates a compensation processing path based on the comparison results. Step 5: The central control system selects and calls the compensated machining path or theoretical machining path as the path source for finishing execution, and controls the five-axis gantry milling machine to perform finishing; during the finishing process, five-axis tilting angle avoidance machining is used for thin-walled parts; Step 6: After the current process is completed, the RGV handling system will move the pallet carrying the workpiece to the next process or buffer area. The workpiece will always maintain the same clamping state as the pallet during the handling process until all processes are completed.

[0006] The workpiece remains clamped on the same pallet throughout the handling process until all processes are completed. Combined with alignment and positioning, this fundamentally eliminates the cumulative errors caused by multiple clamping and positioning in traditional multi-machine operations, improving the consistency and stability of batch production.

[0007] As a preferred embodiment of the technical solution of the present invention, in step two, before the rough machining begins, the workpiece is pre-cooled by a constant temperature cutting fluid through a fluid supply system, so that the workpiece body temperature reaches the predetermined temperature range before the spindle is started for cutting.

[0008] Before rough machining begins, the workpiece is pre-cooled with a constant-temperature cutting fluid to ensure that the workpiece body temperature reaches the predetermined temperature range before starting spindle cutting. This establishes a stable initial temperature field for the workpiece before machining begins, avoiding thermal deformation caused by temperature difference shocks in the early stages of rough machining.

[0009] As a preferred embodiment of the technical solution of the present invention, in step two, the step of the central control system dividing the processing area into a high-rigidity area and a low-rigidity thin-walled area includes: The central control system retrieves the three-dimensional digital model of the titanium alloy slide rail and analyzes the wall thickness characteristics, overhang length to wall thickness ratio, and spatial curvature of each part in the model. The parts with a wall thickness less than the first preset threshold and a ratio of overhang length to wall thickness greater than the second preset threshold, or the parts with a wall thickness less than the first preset threshold and a spatial curvature greater than the third preset threshold, are marked as low-rigidity thin-walled regions. The remaining parts of the three-dimensional digital model, except for those marked as low-rigidity thin-walled regions, are divided into high-rigidity regions.

[0010] No human experience is required for judgment, and it is universal for different specifications of slide rails, ensuring the objectivity and accuracy of the zoning results.

[0011] As a preferred embodiment of the technical solution of the present invention, in step three, measuring the actual geometric dimensions of the key features of the workpiece includes: in-situ measurement of the thickness of the slide rail lugs, in-situ measurement of the depth and contour of the rack groove, and in-situ measurement of the height and position of the normal ribs.

[0012] As a preferred embodiment of the technical solution of the present invention, step three, specifically the steps for measuring the actual geometric dimensions of key features of the workpiece, include: The central control system calls the preset measurement macro program to control the spindle of the five-axis gantry milling machine to automatically switch to a contact-type trigger probe; The central control system generates a probe obstacle avoidance path based on the coordinate positions of key features in the theoretical model, and generates a probe approach path based on the normal direction of the workpiece surface. The contact trigger probe is controlled to move sequentially along the obstacle avoidance path and the approach path, wherein the moving speed on the obstacle avoidance path is greater than the moving speed on the approach path; when the contact trigger probe approaches and contacts the workpiece surface along the normal direction of the workpiece surface, a trigger signal is generated, and the contact point coordinate data in the current machine tool coordinate system is latched and recorded. The central control system acquires the contact coordinate data of each measurement point, and calculates the coordinate difference based on the coordinate data of multiple contact points corresponding to the same key feature to obtain the actual geometric dimension of the key feature, which is then used as the measurement data.

[0013] As a preferred embodiment of the technical solution of the present invention, the steps of the central control system generating a probe obstacle avoidance path based on the coordinate positions of key features in the theoretical model, and generating a probe approach path based on the normal direction of the workpiece surface, include: The central control system analyzes the theoretical model to obtain the three-dimensional spatial coordinates of the key feature preset detection points and the unit normal vector of the surface where the detection point is located; Based on the three-dimensional spatial coordinates of the preset detection point, a preset safe retreat distance is offset outward along the unit normal vector to generate a safe approach point for the probe. A global safety plane is set above the preset detection point, and a spatial non-interference polygonal trajectory is generated from the current position of the contact-triggered probe through the global safety plane to the safe approach point of the probe, which serves as the obstacle avoidance path of the probe. Generate a straight line trajectory from the probe's safe approach point along the unit normal vector toward the preset detection point, as the probe's approach path.

[0014] The probe moves in two stages, along the obstacle avoidance path and the approach path, balancing measurement efficiency and safety; approaching along the normal direction of the workpiece surface ensures the stability of the trigger signal and the accuracy of the measurement data; the global safety plane and the non-interference spatial polygonal trajectory ensure the collision-free and safe movement of the probe on complex slide rail surfaces.

[0015] As a preferred embodiment of the technical solution of the present invention, in step four, the central control system compares the measurement data with the theoretical model, and generates a compensation processing path based on the comparison results, including: The central control system maps the actual geometric dimensions to the theoretical model coordinate system of the titanium alloy slide rail, and calculates the deviation vector between the actual machining position and the theoretical design position of each key feature; Determine whether the magnitude of the deviation vector exceeds a preset machining tolerance threshold; If the magnitude of the deviation vector does not exceed the processing tolerance threshold, the key feature is deemed to be processed successfully, and no compensation processing path is generated. If the magnitude of the deviation vector exceeds the machining tolerance threshold, a compensation machining path is generated to correct the position of the critical feature based on the direction and value of the deviation vector, and the compensation machining path is inserted into the subsequent finishing program segment.

[0016] As a preferred embodiment of the technical solution of the present invention, the specific method for generating the compensation processing path is as follows: taking the contour of the theoretical model as a reference, the reverse value of the deviation vector is superimposed on the coordinates of the corresponding position of the theoretical model to generate the corrected finishing contour path, which is used as the compensation processing path. In step five, when the compensated machining path is generated in step four, the specific steps for the central control system to perform finishing according to the compensated machining path include: The central control system superimposes the compensated machining path onto the theoretical machining path to generate a dynamic finishing program with dimensional corrections. The spindle of the five-axis gantry milling machine is controlled to perform cutting according to the dynamic finishing program to eliminate residual dimensional deviations caused by roughing.

[0017] By calculating the deviation vector and determining the modulus, automatic judgment of whether the machining is qualified is achieved. Compensation paths are only generated when deviations are exceeded, avoiding unnecessary consumption of computational resources. The compensation path is generated by superimposing the inverse values ​​of the deviation vector based on the theoretical model. The compensation direction is opposite to the deviation direction, and the compensation amount corresponds to the deviation amount, achieving precise correction of residual errors in roughing. At the same time, the dual-path selection mechanism of following the compensation path when there is compensation and following the theoretical path when there is no compensation ensures that the correct tool path is always executed in the finishing stage.

[0018] As a preferred embodiment of the technical solution of the present invention, in step five, the specific method of using five-axis swing angle avoidance machining for thin-walled parts during the finishing process is as follows: The central control system controls the tool axis vector of the five-axis gantry milling machine to deflect so that the tool axis forms a preset avoidance angle with the normal direction of the surface to be machined in the thin-walled part of the workpiece. The avoidance angle is 5°-15°. While maintaining the avoidance angle, the tool is controlled to perform side milling along the contour of the thin-walled section to reduce the radial cutting force exerted by the tool on the thin-walled section.

[0019] By forming a 5°-15° avoidance angle between the tool axis and the workpiece surface normal, the tool contacts the thin-walled part in an inclined posture, effectively reducing the squeezing effect of radial cutting force on the thin wall; side milling is performed while maintaining the avoidance angle, further reducing the risk of cutting vibration and tool deformation, and ensuring the contour accuracy and surface quality of thin-walled features such as lugs.

[0020] Secondly, the present invention also provides a roughing and finishing co-processing system for titanium alloy slide rails, used to perform the method described in the first aspect, the system comprising: Multiple five-axis gantry milling machines are used for roughing and finishing titanium alloy slide rail blanks. Each five-axis gantry milling machine is equipped with a fluid supply system to provide constant temperature cutting fluid to the machining area. RGV handling systems are used to move fixtures loaded with workpiece pallets between different processes, enabling the automatic transfer of workpieces between different equipment; The central control system is communicatively connected to the multiple five-axis gantry milling machines and the RGV transport system. It is used to issue start commands to the five-axis gantry milling machines, control the roughing and finishing processes, divide the machining area according to the rigidity differences of each part of the slide rail blank and select the corresponding cutting mode, and generate compensated machining paths or call theoretical machining paths as the source of the finishing execution path based on the comparison results of measurement data and theoretical models. The buffer tray, located at the loading position, is used to support and position the titanium alloy slide rail blank. The workpiece is always clamped on the same buffer tray during the handling process. The online inspection system is communicatively connected to the central control system and is used to measure the actual geometric dimensions of key features of the workpiece in place after rough machining is completed, and to feed the measurement data back to the central control system in real time.

[0021] As can be seen from the above technical solution, this application has the following advantages: intelligent division of high-rigidity and low-rigidity zones. High-rigidity zones utilize large feed rates for cutting to ensure efficiency, while low-rigidity thin-walled zones employ plunge milling, effectively suppressing chatter and tool deformation during thin-walled part machining. While ensuring the machining quality of thin-walled sections, efficient material removal in high-rigidity areas is achieved, improving overall machining efficiency compared to traditional single-strategy machining methods. Simultaneously, the RGV transport system enables automatic workpiece transfer between different devices, and combined with the parallel operation of multiple five-axis gantry milling machines, shortens inter-process auxiliary time.

[0022] By combining constant temperature cutting fluid flushing with a five-axis swing angle avoidance strategy during finishing, thermal deformation caused by cutting heat is controlled at the source. By changing the tool axis vector to reduce the radial cutting force during finishing, the problem of easy deformation and difficulty in ensuring contour accuracy of thin-walled titanium alloy parts is solved.

[0023] By introducing an in-situ measurement and path dynamic compensation mechanism after rough machining, residual stress release deformation and dimensional deviation after rough machining can be detected and corrected in real time, ensuring the dimensional consistency of the final finishing process. Attached Figure Description

[0024] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a production line layout diagram for a specific embodiment of the present invention.

[0026] Figure 2 The present invention relates to a five-axis CNC gantry machining center.

[0027] Figure 3 This invention relates to a material loading position alignment device.

[0028] Figure 4 The structure of the RGV vehicle of the present invention.

[0029] Figure 5 This is a flowchart illustrating the method provided in an embodiment of the present invention.

[0030] In the diagram, 1-CNC five-axis gantry machining center, 2-control center, 3-loading position, 4-unloading position, 5-buffer position, 6-RGV carriage, 7-material transport guide rail, 8-main chip conveyor, 9-machine tool chip conveyor, 10-beam, 11-column, 12-slide, 13-worktable, 14-milling head, 15-tool magazine, 16-slide block, 17-cylinder, 18-Y-axis cable chain, 19-gantry frame, 20-X-axis cable chain, 21-loading position bracket, 22-aligning head, 23-RGV carriage frame, 24-proximity switch, 25-material transmission system, 26-integrated reader / writer, 27-guide device, 28-guide rail, 29-cylindrical pin, 30-photoelectric sensor, 31-exchange position. Detailed Implementation

[0031] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0033] Please see Figure 1 This embodiment provides a roughing and finishing collaborative machining system for titanium alloy slide rails, including a CNC five-axis gantry machining center 1, a control center 2 (i.e., a central control system), an online detection system, a loading position 3, a unloading position 4, a buffer position 5, an RGV trolley 6, a material transport guide rail 7, a main chip conveyor 8, and a machine tool chip conveyor 9.

[0034] During production line operation, the titanium alloy slide rail blank is first installed on the buffer tray at loading position 3, and the workpiece position is aligned using a aligning device. After alignment, the workpiece is moved to the RGV trolley 6 under the transmission of gears and racks. The RGV trolley 6 moves via the material transport guide rail 7. When it reaches the exchange position 31, the automatic table exchange device exchanges the fixture tray with the workpiece with the empty tray at the exchange position 31. At this time, the CNC five-axis gantry machining center 1 can begin machining. The chips generated during machining are collected by the machine tool chip conveyor 9 and then discharged uniformly into the main chip conveyor 8. After machining, the workpiece can be unloaded at unloading position 4, and multiple workpieces can be temporarily stored in the buffer position 5.

[0035] The multiple CNC five-axis gantry machining centers 1 are arranged in a line or matrix, and are provided with loading positions 3, at least one buffer position 5, several processing positions and unloading positions 4 in sequence along the production line direction. The positions are connected by a material transport guide rail 7, and the RGV trolley 6 runs back and forth between the positions along the material transport guide rail 7.

[0036] Please see Figure 2 The CNC five-axis gantry machining center 1 is a fixed beam gantry structure. The gantry frame includes a crossbeam 10 and two side columns 11, a slide 12, a worktable 13, a milling head 14, a tool magazine 15, and a slide 16.

[0037] When the machine tool is working, the movement of the gantry frame along the worktable 13 is the X-axis, the movement of the slide 12 on the crossbeam 10 is the Y-axis, and the movement of the slide 12 on the ram 16 is the Z-axis. The milling head 14 is a double-swivel milling head, with an A-axis that rotates around the X-axis and a C-axis that rotates around the Z-axis, together forming a five-axis machining system that can adapt to the machining of complex surfaces.

[0038] The X, Y, and Z axes are all equipped with preloaded ball screws and a closed-loop feedback device with linear encoders to ensure the positioning accuracy and repeatability of each axis. The spindle features both low-speed high torque and high-speed constant power characteristics. Each five-axis gantry milling machine is equipped with a chain-type tool magazine and various accessory milling heads, enabling five-sided machining.

[0039] The online inspection system includes a contact-triggered probe mounted on the spindle of a five-axis gantry milling machine and a data processing unit communicatively connected to the central control system. When not in measurement mode, the contact-triggered probe is stored in the tool magazine 15, and its structure is similar to that of a cutting tool. When it is necessary to switch tools between roughing, finishing, and in-situ measurement, the automatic tool changer of the chain-type tool magazine 15 removes the milling head 14 from the spindle and stores it in the tool magazine 15. Simultaneously, the contact-triggered probe is retrieved from the tool magazine 15 and installed at the end of the spindle (i.e.,...). Figure 2 (The location of the milling head 14) At this time, the contact-triggered probe is in the measurement working state. After the measurement is completed, the automatic tool changer removes the contact-triggered probe and puts it back into the tool magazine 15, reinstalls the milling head 14, and resumes the machining state. The installation position of the contact-triggered probe shares the spindle end with the milling head 14, therefore... Figure 2 The contact trigger probe is not separately marked; its working position is the same as that of the milling head 14.

[0040] Please see Figure 3 The loading position alignment device includes a cylinder 17, a Y-axis drag chain 18, a gantry frame 19, an X-axis drag chain 20, a loading position bracket 21, and an alignment head 22. The overall structure of the loading position alignment device is a small gantry structure. The alignment head 22 moves under the drive of the cylinder 17, the X-axis drag chain 20, and the Y-axis drag chain 18 to align the workpiece.

[0041] In actual operation, the operator or the central control system controls the alignment head 22 to move near the blank reference surface. The alignment head 22 moves in the X, Y, and Z directions to contact the blank reference surface and obtain the actual position and orientation data of the workpiece. After the position and orientation data is input into the central control system, the central control system uses this data as a basis to correct the machining coordinate system and compensate for blank casting errors and clamping offsets.

[0042] Please see Figure 4 The RGV trolley structure includes an RGV trolley frame 23, a proximity switch 24, a logistics transmission system 25, an integrated reader / writer 26, a guide device 27, a guide rail 28, a cylindrical pin 29, and a photoelectric sensor 30. The RGV trolley 6 moves back and forth on the logistics transmission guide rail 7 via the logistics transmission system 25. The guide device 27 ensures that the trolley does not sway left and right on the guide rail, thus ensuring the stability of logistics transportation.

[0043] The RGV trolley 6 is equipped with an integrated reader / writer 26, which reads the RFID tags on the pallets carrying workpiece information and reports the current process completion status to the central control system in real time. Proximity switches 24 and photoelectric sensors 30 are used to detect the position of the RGV trolley, ensuring that the RGV trolley is accurately positioned at the exchange location of each workstation. The RGV trolley 6 moves along the material transport guide rail 7 using a rack and pinion drive system. The drive mechanism is mounted on the RGV trolley to drive its movement along the material transport guide rail.

[0044] Based on the system provided in the above embodiments, combined with Figures 1-5 This invention also provides a method for coordinating rough and finish machining of titanium alloy slide rails, comprising the following steps: Step 1: Install the titanium alloy slide rail blank onto the buffer tray and complete the alignment; The titanium alloy slide rail blank is installed on the buffer tray of the loading position 3. The buffer tray is equipped with multiple rows of rollers at the bottom and a guide rail at the top of the loading position. The tray moves slowly on the guide rail through the rollers under the transmission of the gear rack.

[0045] The workpiece is aligned using a loading and positioning device. Specifically, the alignment head 22 of the gantry-type three-coordinate alignment device is controlled to move in the X, Y, and Z directions, sequentially contacting the reference surface of the workpiece to acquire its spatial position data. The central control system then corrects the machining coordinate system based on the acquired position data.

[0046] Step 2: The central control system sends a start command to the five-axis gantry milling machine to begin rough machining. During rough machining, the machining area is continuously flushed with constant-temperature cutting fluid through the fluid supply system to keep the temperature of the cutting area within the predetermined temperature range. At the same time, the central control system divides the machining area into high-rigidity areas and low-rigidity thin-walled areas according to the rigidity differences of various parts of the slide rail blank. High-rigidity areas are machined with a large feed rate, while low-rigidity thin-walled areas are machined with plunge milling. The radial cutting force of plunge milling is less than that of high-feed rate cutting. The central control system sends a start command to the five-axis gantry milling machine to begin rough machining.

[0047] In a preferred embodiment, before rough machining begins, the workpiece is pre-cooled with a constant-temperature cutting fluid via a fluid supply system. Once the workpiece temperature reaches a predetermined range, the spindle is then started for cutting. The predetermined temperature range is 22℃ ± 0.5℃.

[0048] During rough machining, a constant-temperature cutting fluid is continuously flushed across the machining area via a fluid supply system to maintain the temperature of the cutting zone within a predetermined range. The fluid supply system includes an external cooling pump located outside the machine tool spindle and a workpiece spray pump located next to the workpiece fixture. The nozzle angle is adjusted via a central control system to supply the constant-temperature cutting fluid to the machining area.

[0049] During the rough machining process, the central control system divides the machining area into a high-rigidity region and a low-rigidity thin-walled region based on the rigidity differences of various parts of the slide rail blank. The specific division steps are as follows: The central control system retrieves the three-dimensional digital model of the titanium alloy slide rail and analyzes the wall thickness characteristics, overhang length to wall thickness ratio, and spatial curvature of each part in the model.

[0050] Regions with a wall thickness less than the first preset threshold and an overhang length to wall thickness ratio greater than the second preset threshold, or regions with a wall thickness less than the first preset threshold and a spatial curvature greater than the third preset threshold, are marked as low-rigidity thin-walled regions.

[0051] For example, the slide rail lugs typically have thinner walls (e.g., 2mm-5mm), a larger overhang ratio (e.g., greater than 5), and smaller spatial curvature. When both the wall thickness and overhang ratio conditions are met, it is designated as a low-rigidity thin-walled region. The slide rail base, on the other hand, has a thicker wall (e.g., 15mm-30mm), does not meet the wall thickness condition, and is therefore classified as a high-rigidity region.

[0052] The remaining parts of the three-dimensional digital model, except for those marked as low-rigidity thin-walled regions, are classified as high-rigidity regions.

[0053] For high-rigidity areas, a large feed rate is used for cutting to improve material removal efficiency. The large feed rate can be 0.15mm-0.35mm per tooth, and the high-torque spindle speed is controlled between 800rpm and 1500rpm.

[0054] For thin-walled areas with low rigidity, plunge milling is used. The plunge milling step distance does not exceed 30% of the tool diameter, and the single-layer cutting depth does not exceed 3mm. Plunge milling allows the tool to feed axially, resulting in low radial cutting force, which can effectively reduce the risk of stress deformation in thin-walled areas.

[0055] For deep grooves, a combination of plunge milling for grooving and side milling for root removal is used. After plunge milling removes most of the excess material, side milling is performed along the groove wall to eliminate the stepped ridges left by plunge milling. The radial cutting depth of the side milling does not exceed 0.5mm.

[0056] Step 3: After rough machining is completed, measure the actual geometric dimensions of the key features of the workpiece and feed the measurement data back to the central control system in real time; In this embodiment of the invention, after rough machining is completed, the actual geometric dimensions of key features of the workpiece are measured in-situ on the machine tool using an online inspection system, and the measurement data is fed back to the central control system in real time. The key features of the workpiece to be measured include: in-situ measurement of the thickness of the slide rail lugs, in-situ measurement of the depth and contour of the rack grooves, and in-situ measurement of the height and position of the normal ribs.

[0057] Specifically, for the ear piece thickness, a measurement section is set every 50mm-100mm along the length of the slide rail. At each section, the two sides of the ear piece are touched to obtain the coordinate values ​​of the two sides. The distance between the two points is the measured ear piece thickness at that section.

[0058] For the rack groove depth, using the workpiece reference surface as a reference, a point on the bottom of the groove is touched to obtain the Z coordinate value. The difference between the Z value at the bottom of the groove and the reference Z value is calculated, which is the measured groove depth. For the rack groove profile, multiple points are touched along the cross-sectional direction of the rack groove, and the coordinates of the multiple points are fitted into a profile curve.

[0059] To determine the height of the normal rib, touch a point at the top of the rib and a point at the bottom of the trench, and calculate the difference in the Z-coordinates of the two points; this difference is the measured rib height. To determine the position of the normal rib, touch a point on each of the two sides of the rib, calculate the coordinates of the midpoints of these points, and compare them with the theoretical positions to obtain the positional deviation.

[0060] The measurement execution process is as follows: The central control system invokes a preset measurement macro program to automatically switch the spindle of the five-axis gantry milling machine to a contact-triggered probe. The central control system generates a probe obstacle avoidance path based on the coordinates of key features in the theoretical model and a probe approach path based on the normal direction of the workpiece surface.

[0061] The specific steps for generating the probe obstacle avoidance path and the probe approach path are as follows: The central control system analyzes the theoretical model to obtain the three-dimensional spatial coordinates of key feature preset detection points and the unit normal vector of the surface where the detection point is located. Based on the three-dimensional spatial coordinates of the preset detection points, a preset safe retreat distance is offset outward along the unit normal vector to generate a probe safe approach point. A global safety plane is set above the preset detection point, and a non-interference spatial polygonal trajectory is generated from the current position of the contact-triggered probe through the global safety plane to the probe safe approach point, serving as the probe obstacle avoidance path. The obstacle avoidance path ensures that the probe maintains a non-contact distance with the workpiece surface and fixture during rapid movement. A straight line trajectory is generated from the probe safe approach point along the unit normal vector towards the preset detection point, serving as the probe approach path.

[0062] The control contact-triggered probe moves sequentially along the obstacle avoidance path and the approach path. The movement speed on the obstacle avoidance path is greater than the movement speed on the approach path.

[0063] When the contact-triggered probe approaches and contacts the workpiece surface along the normal direction, the internal triggering mechanism of the probe activates, generating a trigger signal. The trigger signal is transmitted to the machine tool control system of the five-axis gantry milling machine via a transmission cable or wirelessly, where the machine tool control system latches and records the contact point coordinate data in the current machine tool coordinate system.

[0064] The central control system obtains the contact coordinate data of each measurement point from the machine tool control system, and calculates the coordinate difference based on the coordinate data of multiple contact points corresponding to the same key feature to obtain the actual geometric dimension of the key feature, which is then used as the measurement data.

[0065] Step 4: The central control system compares the measurement data with the theoretical model and generates a compensation processing path based on the comparison results; the specific steps are as follows: The central control system maps the actual geometric dimensions to the coordinate system of the theoretical model of the titanium alloy slide rail, and calculates the deviation vector between the actual machined position and the theoretical design position of each key feature. The direction of the deviation vector indicates the offset direction of the actual machined position relative to the theoretical position, and the value of the deviation vector indicates the magnitude of the offset.

[0066] Determine whether the magnitude of the deviation vector exceeds the preset machining tolerance threshold. The machining tolerance threshold is set according to the accuracy requirements of the slide rail.

[0067] If the magnitude of the deviation vector does not exceed the machining tolerance threshold, the key feature is deemed to be machining qualified, and no compensation machining path is generated.

[0068] If the magnitude of the deviation vector exceeds the machining tolerance threshold, a compensation machining path is generated based on the direction and value of the deviation vector to correct the position of the critical feature, and the compensation machining path is inserted into the subsequent finishing program segment.

[0069] The specific method for generating the compensation machining path is as follows: taking the contour of the theoretical model as a reference, the reverse value of the deviation vector is superimposed on the coordinates of the corresponding position of the theoretical model to generate the corrected finishing contour path, which serves as the compensation machining path.

[0070] Step 5: The central control system selects and calls the compensated machining path or the theoretical machining path as the path source for finishing, and controls the five-axis gantry milling machine to perform finishing. During finishing, five-axis tilting angle avoidance machining is used for thin-walled parts. If a compensated machining path was generated in Step 4, finishing is performed according to the compensated machining path. Specifically, the central control system superimposes the compensated machining path onto the theoretical machining path to generate a dynamic finishing program with dimensional corrections. The spindle of the five-axis gantry milling machine is controlled to perform cutting according to the dynamic finishing program to eliminate residual dimensional deviations generated during roughing. If a compensated machining path was not generated in Step 4, finishing is performed according to the theoretical machining path, which is a path generated based on a theoretical model. The specific generation method adopts existing technology.

[0071] During the finishing process, a five-axis tilting angle avoidance machining method is used for thin-walled sections. The specific method is as follows: The central control system controls the tool axis vector of the five-axis gantry milling machine to deflect, so that the tool axis forms a preset avoidance angle with the normal direction of the surface to be machined on the thin-walled part of the workpiece. The avoidance angle is 5°-15°.

[0072] For thin-walled sections with poor rigidity (including the edges of the lugs and areas with large overhangs in this embodiment), a larger avoidance angle is used; for sections with slightly better rigidity, a smaller avoidance angle is used. The avoidance angle is dynamically adjusted according to the rigidity of the thin-walled section, with a larger avoidance angle for sections with lower rigidity.

[0073] While maintaining the avoidance angle, control the tool to perform side milling along the contour of the thin-walled section to reduce the radial cutting force exerted by the tool on the thin-walled section, thereby reducing the risk of cutting vibration and tool deformation.

[0074] During finishing, the cutting fluid is kept at a constant temperature of 22℃±0.5℃, but the flow rate can be appropriately reduced to 60%-70% of the flow rate during roughing to avoid elastic deformation of thin-walled parts caused by the impact of high-pressure cutting fluid.

[0075] Step 6: After the current process is completed, the RGV handling system will move the pallet carrying the workpiece to the next process or buffer area. The workpiece will always maintain the same clamping state as the pallet during the handling process until all processes are completed.

[0076] Specifically, after a single five-axis gantry machining center completes the current process, the automatic table exchange device exchanges the fixture pallet with the workpiece with the empty pallet at the exchange position, and the RGV trolley transports the processed workpiece pallet to the next process equipment or buffer area.

[0077] As the RGV trolley moves along the logistics transport rail, a guiding device ensures its stable movement on the rail. Proximity switches and photoelectric sensors detect the trolley's position in real time, ensuring precise positioning at each workstation's exchange point. An integrated reader reads the RFID tags on the pallets carrying workpiece information and reports the current process completion status to the central control system in real time, achieving traceable management of the entire process flow.

[0078] Throughout the handling process, the workpiece remains clamped on the same buffer pallet without being re-clamped. The buffer pallet, through a zero-point positioning system, is repeatedly positioned in conjunction with the machine tool table and RGV carriage, with a repeatability of no less than ±0.01mm, until all machining operations are completed. During handling, the zero-point positioning system maintains the workpiece's clamping state, ensuring consistency of the machining datum throughout the entire process.

[0079] The central control system includes the following functional modules: The machining control module is configured to issue start commands to the five-axis gantry milling machine and control the execution of roughing and finishing processes.

[0080] The rigid partitioning module is configured to analyze the three-dimensional digital model of the titanium alloy slide rail and divide the processing area into a high-rigidity area and a low-rigidity thin-walled area based on the comparison results of the characteristics of each part with the preset threshold.

[0081] The measurement control module is configured to control the online detection system to generate probe obstacle avoidance paths and probe approach paths, and to acquire in-situ measurement data.

[0082] The comparison and compensation module is configured to compare the measurement data with the theoretical model and generate a compensation processing path or call the theoretical processing path based on the comparison results.

[0083] The avoidance control module is configured to control the tool axis vector of the five-axis gantry milling machine to deflect during the finishing process, so that the tool axis forms an avoidance angle of 5°-15° with the normal direction of the surface to be machined in the thin-walled part of the workpiece.

[0084] The production scheduling module is configured to issue production scheduling instructions to the RGV transport system based on the real-time processing status and production scheduling priority of each machine tool.

[0085] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for coordinating rough and finish machining of titanium alloy slide rails, characterized in that, This is achieved through a flexible production line that includes multiple five-axis gantry milling machines, an RGV handling system, and a central control system, and includes the following steps: Step 1: Install the titanium alloy slide rail blank onto the buffer tray and complete the alignment; Step 2: The central control system sends a start command to the five-axis gantry milling machine to begin rough machining. During rough machining, the machining area is continuously flushed with constant-temperature cutting fluid through the fluid supply system to keep the temperature of the cutting area within the predetermined temperature range. At the same time, the central control system divides the machining area into high-rigidity areas and low-rigidity thin-walled areas according to the rigidity differences of various parts of the slide rail blank. High-rigidity areas are machined with a large feed rate, while low-rigidity thin-walled areas are machined with plunge milling. The radial cutting force of plunge milling is less than that of high-feed rate cutting. Step 3: After rough machining is completed, measure the actual geometric dimensions of the key features of the workpiece and feed the measurement data back to the central control system in real time; Step 4: The central control system compares the measurement data with the theoretical model and generates a compensation processing path based on the comparison results. Step 5: The central control system selects and calls the compensated machining path or theoretical machining path as the path source for finishing execution, and controls the five-axis gantry milling machine to perform finishing; during the finishing process, five-axis tilting angle avoidance machining is used for thin-walled parts; Step 6: After the current process is completed, the RGV handling system will move the pallet carrying the workpiece to the next process or buffer area. The workpiece will always maintain the same clamping state as the pallet during the handling process until all processes are completed.

2. The method for rough and finish machining of titanium alloy slide rails according to claim 1, characterized in that, In step two, before rough machining begins, the workpiece is pre-cooled with constant-temperature cutting fluid through the fluid supply system. Once the workpiece body temperature reaches the predetermined temperature range, the spindle is started for cutting.

3. The rough and finish machining method for titanium alloy slide rails according to claim 1, characterized in that, In step two, the central control system divides the processing area into a high-rigidity region and a low-rigidity thin-walled region, including: The central control system retrieves the three-dimensional digital model of the titanium alloy slide rail and analyzes the wall thickness characteristics, overhang length to wall thickness ratio, and spatial curvature of each part in the model. The parts with a wall thickness less than the first preset threshold and a ratio of overhang length to wall thickness greater than the second preset threshold, or the parts with a wall thickness less than the first preset threshold and a spatial curvature greater than the third preset threshold, are marked as low-rigidity thin-walled regions. The remaining parts of the three-dimensional digital model, except for those marked as low-rigidity thin-walled regions, are divided into high-rigidity regions.

4. The roughing and finishing co-processing method for titanium alloy slide rails according to claim 1, characterized in that, The actual geometric dimensions of key features of the workpiece include: in-situ measurement of the thickness of the slide rail lugs, in-situ measurement of the depth and contour of the rack grooves, and in-situ measurement of the height and position of the normal ribs.

5. The roughing and finishing co-processing method for titanium alloy slide rails according to claim 4, characterized in that, Step three, the specific steps for measuring the actual geometric dimensions of the workpiece's key features, include: The central control system calls the preset measurement macro program to control the spindle of the five-axis gantry milling machine to automatically switch to a contact-type trigger probe; The central control system generates a probe obstacle avoidance path based on the coordinate positions of key features in the theoretical model, and generates a probe approach path based on the normal direction of the workpiece surface. The contact trigger probe is controlled to move sequentially along the obstacle avoidance path and the approach path, wherein the moving speed on the obstacle avoidance path is greater than the moving speed on the approach path; when the contact trigger probe approaches and contacts the workpiece surface along the normal direction of the workpiece surface, a trigger signal is generated, and the contact point coordinate data in the current machine tool coordinate system is latched and recorded. The central control system acquires the contact coordinate data of each measurement point, and calculates the coordinate difference based on the coordinate data of multiple contact points corresponding to the same key feature to obtain the actual geometric dimension of the key feature, which is then used as the measurement data.

6. The method for rough and finish machining of titanium alloy slide rails according to claim 5, characterized in that, The steps of the central control system in generating the probe obstacle avoidance path based on the coordinate positions of key features in the theoretical model, and generating the probe approach path based on the normal direction of the workpiece surface, include: The central control system analyzes the theoretical model to obtain the three-dimensional spatial coordinates of the key feature preset detection points and the unit normal vector of the surface where the detection point is located; Based on the three-dimensional spatial coordinates of the preset detection point, a preset safe retreat distance is offset outward along the unit normal vector to generate a safe approach point for the probe. A global safety plane is set above the preset detection point, and a spatial non-interference polygonal trajectory is generated from the current position of the contact-triggered probe through the global safety plane to the safe approach point of the probe, which serves as the obstacle avoidance path of the probe. Generate a straight line trajectory from the probe's safe approach point along the unit normal vector toward the preset detection point, as the probe's approach path.

7. The method for rough and finish machining of titanium alloy slide rails according to claim 1, characterized in that, In step four, the central control system compares the measured data with the theoretical model, and generates a compensated processing path based on the comparison results. This process includes: The central control system maps the actual geometric dimensions to the theoretical model coordinate system of the titanium alloy slide rail, and calculates the deviation vector between the actual machining position and the theoretical design position of each key feature; Determine whether the magnitude of the deviation vector exceeds a preset machining tolerance threshold; If the magnitude of the deviation vector does not exceed the processing tolerance threshold, the key feature is deemed to be processed successfully, and no compensation processing path is generated. If the magnitude of the deviation vector exceeds the machining tolerance threshold, a compensation machining path is generated to correct the position of the critical feature based on the direction and value of the deviation vector, and the compensation machining path is inserted into the subsequent finishing program segment.

8. The method for rough and finish machining of titanium alloy slide rails according to claim 7, characterized in that, The specific method for generating the compensation machining path is as follows: taking the contour of the theoretical model as a reference, the reverse value of the deviation vector is superimposed on the coordinates of the corresponding position of the theoretical model to generate the corrected finishing contour path, which serves as the compensation machining path. In step five, when the compensated machining path is generated in step four, the specific steps for the central control system to perform finishing according to the compensated machining path include: The central control system superimposes the compensated machining path onto the theoretical machining path to generate a dynamic finishing program with dimensional corrections. The spindle of the five-axis gantry milling machine is controlled to perform cutting according to the dynamic finishing program to eliminate residual dimensional deviations caused by roughing.

9. The method for rough and finish machining of titanium alloy slide rails according to claim 1, characterized in that, In step five, the specific method of using five-axis sway angle avoidance machining for thin-walled areas during the finishing process is as follows: The central control system controls the tool axis vector of the five-axis gantry milling machine to deflect so that the tool axis forms a preset avoidance angle with the normal direction of the surface to be machined in the thin-walled part of the workpiece. The avoidance angle is 5°-15°. While maintaining the avoidance angle, the tool is controlled to perform side milling along the contour of the thin-walled section to reduce the radial cutting force exerted by the tool on the thin-walled section.

10. A roughing and finishing co-machining system for titanium alloy slide rails, characterized in that, The system for performing the method according to any one of claims 1-9, the system comprising: Multiple five-axis gantry milling machines are used for roughing and finishing titanium alloy slide rail blanks. Each five-axis gantry milling machine is equipped with a fluid supply system to provide constant temperature cutting fluid to the machining area. RGV handling systems are used to move fixtures loaded with workpiece pallets between different processes, enabling the automatic transfer of workpieces between different equipment; The central control system is communicatively connected to the multiple five-axis gantry milling machines and the RGV transport system. It is used to issue start commands to the five-axis gantry milling machines, control the roughing and finishing processes, divide the machining area according to the rigidity differences of each part of the slide rail blank and select the corresponding cutting mode, and generate compensated machining paths or call theoretical machining paths as the source of the finishing execution path based on the comparison results of measurement data and theoretical models. The buffer tray, located at the loading position, is used to support and position the titanium alloy slide rail blank. The workpiece is always clamped on the same buffer tray during the handling process. The online inspection system is communicatively connected to the central control system and is used to measure the actual geometric dimensions of key features of the workpiece in situ after rough machining is completed, and to feed the measurement data back to the central control system in real time.

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