Rapid alignment method for machining of large-size special-shaped structural part

Abstract

A large-size special-shaped structural part machining rapid alignment method comprises the core steps that a reference part is installed, specifically, at least four non-collinear spherical screws are fastened to a component process block / redundant rough material, and at least four evenly-distributed adhesive balls are pasted to different side faces of the outer surface of a component; a three-dimensional scanner with the precision smaller than or equal to 0.01 mm is adopted for scanning the component, point cloud data and a design model are registered through an iterative nearest point algorithm, and theoretical sphere center coordinates of the spherical screw and the adhesive ball are obtained. Double-reference cooperation is adopted, three-dimensional scanning and numerical control automation are combined, whole-process multi-link control precision and alignment efficiency are high, precision is reliable, and the method is suitable for large-scale production. And the assembly can be reused, is adaptive to different numerical control systems, and is suitable for alignment of various large-size special-shaped structural parts before machining.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical processing, in particular to a quick alignment method for machining large-size special-shaped structural parts. BACKGROUND

[0002] In the modern high-end manufacturing field, the demand for large-size special-shaped structural parts is increasing, and the complexity of their structure and the particularity of their size make the alignment positioning step before machining a production bottleneck. The essence of alignment positioning is to completely match the actual spatial posture of the part with the design model posture, ensuring that the subsequent machining size and shape tolerance meet the drawing requirements, which is a key pre-process that determines the machining quality.

[0003] In the prior art, the alignment of large-size special-shaped structural parts generally uses the traditional process of "sticking steel balls - three-dimensional scanning - repeatedly padding blocks - verifying with a gauge", and the specific operation logic is as follows: first, the operator selects several flat areas on the surface of the part according to experience, and pastes stainless steel balls with a diameter of 10-15mm as temporary positioning reference through instant adhesive; then, a three-dimensional scanner is used to scan the part and the steel balls to obtain the spatial coordinate data of the center of the steel ball; then, the part is hoisted to the platform of the numerical control machine tool by the bridge crane, and metal pads with a thickness of 0.1-5mm are padded under the bottom surface of the part or the reserved process block, after each padding, the part needs to be hoisted again, and a dial gauge or a micrometer is used to measure the position deviation of the steel ball, if the deviation exceeds the allowed range, the thickness of the pad is adjusted again, and the above process is repeated until the deviation meets the requirements.

[0004] The existing traditional alignment method cannot meet the production needs of "high efficiency, high precision, low dependence, wide adaptability" of large-size special-shaped structural parts in the modern manufacturing field, and a technical solution that breaks through the traditional idea is urgently needed to solve the core problems of time consumption, precision, and adaptability from the principle level. SUMMARY

[0005] To solve the above problems, the present application uses an integrated technical process of "reference part design - three-dimensional scanning modeling - point program generation - support assembly positioning - structural part installation - precision verification - maintenance and recycling", combined with three core technologies of "automatic centering positioning of spherical surface", "hydraulic stable support", and "double reference independent verification", to realize the quick and high-precision alignment of large-size special-shaped structural parts.

[0006] To achieve the above purpose, the present application adopts the following technical solution: a quick alignment method for machining large-size special-shaped structural parts, comprising the following steps: Step 1: installation of reference elements, install positioning reference elements and verification reference elements on the large-size special-shaped structural member to be machined, the positioning reference elements are spherical screws, and the verification reference elements are adhesive balls; wherein the number of installed spherical screws is at least 4, and the installation positions of all spherical screws are not collinear, each spherical screw is fastened on the process block or the excess material of the large-size special-shaped structural member through thread cooperation, the excess material is the reserved material which does not affect the subsequent machining of the large-size special-shaped structural member; the number of installed adhesive balls is at least 4, each adhesive ball is pasted on the outer surface of the large-size special-shaped structural member through glue, and the pasting positions of all adhesive balls are uniformly distributed on different sides of the large-size special-shaped structural member; Step 2: three-dimensional scanning and coordinate acquisition, a three-dimensional scanner is used to scan the large-size special-shaped structural member installed with spherical screws and adhesive balls in the whole range, and point cloud data containing the spherical surfaces of all spherical screws and the spherical surfaces of adhesive balls are obtained; based on the design model of the large-size special-shaped structural member, the point cloud data is registered with the design model, and the spatial coordinates of the centers of all spherical screws and the centers of adhesive balls in the preset coordinate system when the large-size special-shaped structural member is in the theoretical machining posture are fitted to obtain the spherical screw center coordinates and the adhesive ball center coordinates respectively; Step 3: point program generation, the spherical screw center coordinates obtained in step 2 are imported into a computer-aided software, the computer-aided software converts the spherical screw center coordinates into a point program recognizable by a numerical control machine tool according to the coordinate system parameters of the numerical control machine tool, the point program includes the X-axis coordinate, Y-axis coordinate and Z-axis coordinate of the corresponding support point of each spherical screw in the machine tool coordinate system, and the attitude adjustment parameters when the subsequent positioning assembly and support assembly cooperate, the attitude adjustment parameters include the rotation angle of the positioning assembly around the X-axis and the rotation angle around the Y-axis; Step 4: connecting the positioning assembly and the support assembly, detachably connecting the quick positioning rod and the spindle sleeve of the numerical control machine tool, after connection, ensuring that the coaxiality error between the axis of the quick positioning rod and the axis of the spindle of the numerical control machine tool is ≤0.005mm; connecting the spherical surface adapter block of the movable support assembly and the quick positioning rod through spherical surface cooperation, the inner spherical surface of the spherical surface adapter block is fitted with the outer spherical surface of the quick positioning rod, and the fitting gap is ≤0.02mm; locking and fixing the spherical surface adapter block and the quick positioning rod through the fastening nut, the inner thread of the fastening nut cooperates with the outer thread of the spherical surface adapter block, and after locking, ensuring that the spherical surface adapter block and the quick positioning rod have no relative displacement; Step 5: Position and clamp the support assembly. Start the CNC machine tool and call the point program generated in Step 3. The CNC machine tool drive spindle to move the quick positioning rod and the movable support assembly connected to it to the support point corresponding to the first ball screw. Control the hydraulic support of the movable support assembly to stretch naturally until the bottom of the hydraulic support is in complete contact with the CNC machine tool platform. Lock the hydraulic support through the locking mechanism of the hydraulic support. After locking, the axial displacement of the hydraulic support is ≤0.01mm. Control the CNC machine tool spindle to separate the quick positioning rod from the spherical adapter block to complete the positioning and clamping of the first movable support assembly. Repeat Step 4 and Step 5 to complete the positioning and clamping of the movable support assemblies corresponding to all remaining ball screws in sequence. After the positioning of all movable support assemblies is completed, the support surfaces of each movable support assembly are on the same theoretical plane with a flatness error of ≤0.03mm. Step 6: Part installation and positioning. Hoist the large-sized irregular structural component onto the CNC machine tool platform, aligning each spherical screw on the large-sized irregular structural component with the corresponding spherical adapter block of the movable support assembly. Slowly lower the large-sized irregular structural component, so that the outer spherical surface of each spherical screw fits against the inner spherical surface of the corresponding spherical adapter block. After fitting, use the auxiliary clamping mechanism of the movable support assembly to fix the spherical screw and the spherical adapter block. After fixing, the relative displacement between the spherical screw and the spherical adapter block is ≤0.008mm. Step 7: Verify the alignment status. Use a 3D scanner again to scan all the adhesive balls on the large-sized irregular-shaped structural component to obtain the actual center coordinates of each adhesive ball. Compare the actual center coordinates with the center coordinates of the adhesive balls obtained in Step 2 and calculate the coordinate deviation value of each adhesive ball center. If the coordinate deviation value of all adhesive balls is ≤0.05mm, the large-sized irregular-shaped structural component is considered to be aligned successfully. If there are adhesive balls with a coordinate deviation value >0.05mm, adjust the extension and retraction of the hydraulic bracket of the movable support component at the corresponding position until the coordinate deviation value of all adhesive balls is ≤0.05mm, thus completing the rapid alignment of the large-sized irregular-shaped structural component.

[0007] Furthermore, in step 1, the thread specification of the ball screw matches the thread hole specification of the large-size irregular structural component process block or excess raw material, and the thread fit accuracy grade is 6H / 5g; the adhesive is a high-strength anaerobic adhesive with a shear strength ≥20MPa and no significant performance degradation in the temperature range of -20℃ to 80℃; the adhesive ball is made of stainless steel with a surface roughness Ra≤0.8μm and a sphericity error ≤0.005mm.

[0008] Furthermore, in step 2, the scanning accuracy of the 3D scanner is ≤0.01mm, and the scanning point cloud density is ≥5 points per square millimeter; the preset coordinate system is the design reference coordinate system for large-sized irregular structural parts, with the key machining surface of the large-sized irregular structural parts as the XY plane and the axis of the key machining hole as the Z axis; the registration of the point cloud data with the design model adopts the iterative nearest point algorithm, and the root mean square error after registration is ≤0.02mm.

[0009] Furthermore, in step 3, the computer-aided software is CAD / CAM integrated software, which has coordinate transformation, program compilation, and simulation functions; the format of the point-to-point program matches the control system of the CNC machine tool. If the CNC machine tool is a FANUC system, the point-to-point program adopts G-code format; if it is a SIEMENS system, the point-to-point program adopts M-code format; the point-to-point program also includes safety movement instructions, which set the safety distance when the CNC machine tool spindle drives the positioning component to move. The safety distance is the minimum distance ≥ 50mm between the positioning component and the large-sized irregular structural parts and the machine tool platform.

[0010] Furthermore, in step 4, the quick positioning rod is made of 40Cr material, with a nitrided surface, a nitrided layer thickness of 0.15mm~0.3mm, and a surface hardness of HV550~HV650; the quick positioning rod is connected to the spindle tool sleeve by a tapered fit with a taper of 7:24 and a fit clearance ≤0.003mm; the fastening nut is made of 304 stainless steel, with an internal thread accuracy grade of 5H, and the coaxiality error between the inner hole of the nut and the outer circle of the spherical adapter block is ≤0.01mm.

[0011] Furthermore, in step 4, the movable support assembly also includes fastening screws. The fastening screws are used to connect the spherical adapter block and the hydraulic support. The fastening screws are M12×30, made of high-strength alloy steel 12.9 grade, and have a tightening torque of 80 N·m to 100 N·m. The inner spherical radius of the spherical adapter block is consistent with the outer spherical radius of the quick positioning rod, with a tolerance of ±0.002 mm. The inner spherical surface is polished, with a roughness Ra≤0.4 μm.

[0012] Furthermore, in step 5, the hydraulic support is a single-acting hydraulic jack with a rated support force ≥50kN, a telescopic stroke of 50mm~150mm, and a telescopic accuracy of ≤0.005mm; the locking mechanism is a hydraulic lock, and the pressure holding time of the hydraulic support after locking is ≥24h, with a pressure attenuation of ≤5%; the surface roughness Ra of the CNC machine tool platform is ≤0.8μm, the flatness error is ≤0.01mm / m, and the contact area between the movable support component and the machine tool platform is ≥90% of the bottom area of ​​the hydraulic support.

[0013] Furthermore, in step 6, the hoisting is carried out using a bridge crane with a hoisting accuracy of ≤0.1mm. During the hoisting process, the swing amplitude of the large-sized irregular structural component is controlled to be ≤5mm through a guide mechanism. The auxiliary clamping mechanism is a manual clamping wrench with a clamping force of 500N~800N. After clamping, the clamping torque is detected by a torque wrench to ensure that the torque value is stable within a preset range of ±5%. The outer spherical surface roughness Ra of the ball screw is ≤0.4μm, and the sphericity error is ≤0.003mm.

[0014] Furthermore, in step 7, the 3D scanner parameters during the second scan are kept consistent with those in step 2. The temperature of the scanning environment is controlled at 20℃±2℃, and the humidity is controlled at 40%~60% to avoid airflow interference. The coordinate comparison uses professional measurement software with deviation analysis and graphical display functions, which can generate a deviation report. The deviation report includes the X-axis deviation, Y-axis deviation, Z-axis deviation, and total deviation of each adhesive ball. The hydraulic support is adjusted using a micro-adjustment method, with each adjustment amount being 0.001mm~0.005mm. After adjustment, the system is left to stand for 5 minutes before scanning verification.

[0015] Furthermore, step 8 is included: post-alignment maintenance and device recovery. After the large-size irregular structural parts are aligned and qualified, the locking status of the movable support components is checked regularly during processing, once every 2 hours, to ensure there is no loosening. After processing, the auxiliary clamping mechanism of the movable support components is removed first, then the locking mechanism of the hydraulic support is loosened, the hydraulic support is retracted to the initial position, and the connection between the spherical adapter block and the quick positioning rod is removed. The spherical screws are cleaned to remove surface oil. If the threads are intact, they can be used for the alignment of the next large-size irregular structural parts of the same type. The spherical structure of the movable support components is cleaned, rust-preventive oil is applied, and it is stored in a special toolbox for later use. The rust-preventive oil is an extreme pressure rust-preventive oil with a rust prevention period of ≥12 months.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The 3D scanning of this invention is completed automatically by the equipment (operators only need to set the scanning parameters), the point program is automatically generated by the software (no need to manually write G / M code), the positioning of the support components is driven by the CNC machine tool (no need to manually push), and the hoisting of parts is completed by the bridge crane (lifting accuracy ≤0.1mm) in conjunction with the guide mechanism (swing amplitude ≤5mm). Operators only need to monitor the process at the control console. New technicians can operate independently after one month of training, which greatly reduces the dependence on senior technicians.

[0017] The positioning program of this invention includes a safe movement command (minimum distance between the positioning component and the part / machine platform ≥ 50mm) to avoid collision between the support component and the part when moving; the hydraulic support uses a single-acting hydraulic jack (rated support force ≥ 50kN, far exceeding the weight of the part), in conjunction with a hydraulic locking mechanism (pressure holding time ≥ 24h, pressure decay ≤ 5%) to ensure stable support of the part and prevent tipping; the auxiliary clamping mechanism uses a torque wrench for detection (clamping torque fluctuation ≤ ± 5%) to avoid insufficient clamping force leading to part displacement or excessive clamping force damaging the part.

[0018] The entire process of this invention is dominated by equipment and software, avoiding subjective errors caused by manual operation (such as visual deviations when scribing lines or uneven force when installing tooling). The alignment accuracy deviation of different operators and different batches of parts is ≤0.01mm, which greatly improves the consistency of processing and reduces the scrap rate of parts due to alignment deviation (the scrap rate of parts using traditional methods is about 2-3%, while this invention can reduce it to below 0.5%). Attached Figure Description

[0019] Figure 1 This is a system block diagram of the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figure 1 As shown, an embodiment of the present invention proposes a method for rapid alignment during machining of large-sized irregularly shaped structural parts, the method comprising the following steps: Step 1: Mounting of reference components. Positioning and verification reference components are mounted on the large-sized irregular-shaped structural component to be processed. The positioning reference component is a ball screw, and the verification reference component is an adhesive ball. At least four ball screws are installed, and their positions are not collinear. Each ball screw is threaded onto a process block or excess material of the large-sized irregular-shaped structural component. The excess material is reserved material that will not affect subsequent processing of the large-sized irregular-shaped structural component. At least four adhesive balls are installed, and each adhesive ball is glued to the outer surface of the large-sized irregular-shaped structural component, with the glued positions of all adhesive balls evenly distributed on different sides of the large-sized irregular-shaped structural component. Step 2: 3D scanning and coordinate acquisition. A 3D scanner is used to perform a full-range scan on the large-sized irregular-shaped structural component with ball screws and adhesive balls installed, acquiring point cloud data containing the spherical surfaces of all ball screws and adhesive balls. Based on the design model of the large-sized irregular-shaped structural component, the point cloud data is registered with the design model, and the spatial coordinates of the centers of all ball screws and adhesive balls in the preset coordinate system are obtained when the large-sized irregular-shaped structural component is in the theoretical processing posture. These coordinates are recorded as the ball screw center coordinates and adhesive ball center coordinates, respectively. Step 3: Point program generation. The ball center coordinates of the spherical screws obtained in Step 2 are imported into the computer-aided software. The computer-aided software converts the ball center coordinates of the spherical screws into a point program that can be recognized by the CNC machine tool according to the coordinate system parameters of the CNC machine tool. The point program includes the X-axis coordinates, Y-axis coordinates, and Z-axis coordinates of the support point corresponding to each spherical screw in the machine tool coordinate system, as well as the attitude adjustment parameters when the positioning component and the support component cooperate. The attitude adjustment parameters include the rotation angle of the positioning component around the X-axis and the rotation angle around the Y-axis. Step 4: Connect the positioning component and the support component. Make a detachable connection between the quick-positioning rod and the spindle sleeve of the CNC machine tool. After connection, ensure that the coaxiality error between the axis of the quick-positioning rod and the axis of the CNC machine tool spindle is ≤0.005mm. Connect the spherical adapter block of the movable support component to the quick-positioning rod using a spherical fit. The inner spherical surface of the spherical adapter block fits against the outer spherical surface of the quick-positioning rod, with a fit gap ≤0.02mm. Lock the spherical adapter block and the quick-positioning rod together using a fastening nut. The internal thread of the fastening nut engages with the external thread of the spherical adapter block. After locking, ensure that there is no relative displacement between the spherical adapter block and the quick-positioning rod. Step 5: Position and clamp the support assembly. Start the CNC machine tool and call the point program generated in Step 3. The CNC machine tool drive spindle to move the quick positioning rod and the movable support assembly connected to it to the support point corresponding to the first ball screw. Control the hydraulic support of the movable support assembly to stretch naturally until the bottom of the hydraulic support is in complete contact with the CNC machine tool platform. Lock the hydraulic support through the locking mechanism of the hydraulic support. After locking, the axial displacement of the hydraulic support is ≤0.01mm. Control the CNC machine tool spindle to separate the quick positioning rod from the spherical adapter block to complete the positioning and clamping of the first movable support assembly. Repeat Step 4 and Step 5 to complete the positioning and clamping of the movable support assemblies corresponding to all remaining ball screws in sequence. After the positioning of all movable support assemblies is completed, the support surfaces of each movable support assembly are on the same theoretical plane with a flatness error of ≤0.03mm. Step 6: Part installation and positioning. Hoist the large-sized irregular structural component onto the CNC machine tool platform, aligning each spherical screw on the large-sized irregular structural component with the corresponding spherical adapter block of the movable support assembly. Slowly lower the large-sized irregular structural component, so that the outer spherical surface of each spherical screw fits against the inner spherical surface of the corresponding spherical adapter block. After fitting, use the auxiliary clamping mechanism of the movable support assembly to fix the spherical screw and the spherical adapter block. After fixing, the relative displacement between the spherical screw and the spherical adapter block is ≤0.008mm. Step 7: Verify the alignment status. Use a 3D scanner again to scan all the adhesive balls on the large-sized irregular-shaped structural component to obtain the actual center coordinates of each adhesive ball. Compare the actual center coordinates with the center coordinates of the adhesive balls obtained in Step 2 and calculate the coordinate deviation value of each adhesive ball center. If the coordinate deviation value of all adhesive balls is ≤0.05mm, the large-sized irregular-shaped structural component is considered to be aligned successfully. If there are adhesive balls with a coordinate deviation value >0.05mm, adjust the extension and retraction of the hydraulic support of the movable support component at the corresponding position until the coordinate deviation value of all adhesive balls is ≤0.05mm, thus completing the rapid alignment of the large-sized irregular-shaped structural component.

[0022] Furthermore, when machining and aligning a large, irregularly shaped structural component, firstly, spherical screws are installed on the process blocks and excess material of the component (ensuring they are not collinear), and adhesive balls are attached to different sides of the outer surface. Next, a 3D scanner is used to scan the component, acquiring point cloud data of two reference components. This data is then registered with the design model to obtain the spatial coordinates of the sphere centers of the two reference components under the theoretical posture. Subsequently, the coordinates of the spherical screw centers are imported into computer-aided software and converted into a point-position program (including support point coordinates and posture adjustment parameters) recognizable by the CNC machine tool. Finally, the quick-positioning rod is detachably connected to the machine tool spindle sleeve while ensuring coaxiality, allowing the movement... After the spherical adapter block of the support component mates with the spherical quick-positioning rod, it locks in place. The machine tool is then started, and the positioning and support components are driven to the first spherical screw support point. The hydraulic support is stretched and locked after contacting the machine tool platform. The positioning rod is then separated from the spherical adapter block, completing the positioning and clamping of the first support component. This process is repeated for the remaining support components. Afterward, the structural components are hoisted so that the spherical screws are aligned and fitted with the corresponding spherical adapter blocks, and then fixed with an auxiliary clamping mechanism. Finally, the adhesive ball is scanned again to obtain the actual coordinates, which are compared with the theoretical coordinates. If the deviation exceeds the standard, the hydraulic support is adjusted until all deviations are within acceptable limits, completing the alignment.

[0023] Step 1.1: The thread specification of the ball screw matches the thread hole specification of the large-size irregular structural component process block or excess raw material, and the thread fit accuracy grade is 6H / 5g; the adhesive is a high-strength anaerobic adhesive with a shear strength ≥20MPa and no significant performance degradation in the temperature range of -20℃ to 80℃; the adhesive ball is made of stainless steel with a surface roughness Ra≤0.8μm and a sphericity error ≤0.005mm.

[0024] Furthermore, when selecting ball screws, ensure that their thread specifications match the thread hole specifications on the structural component process block and excess material to ensure a stable fit between the two. When attaching adhesive balls, use high-strength anaerobic adhesive, which maintains stable performance within a common temperature range and can firmly bond the adhesive balls to the outer surface of the structural component. Use stainless steel adhesive balls, whose surface is treated to ensure smoothness and spherical regularity, providing a guarantee for obtaining accurate point cloud data in subsequent 3D scanning.

[0025] Step 1.2: The scanning accuracy of the 3D scanner is ≤0.01mm, and the scanning point cloud density is ≥5 points per square millimeter; the preset coordinate system is the design reference coordinate system for large-sized irregular structural parts, with the key machining surface of the large-sized irregular structural parts as the XY plane and the axis of the key machining hole as the Z axis; the registration of the point cloud data and the design model adopts the iterative nearest point algorithm, and the root mean square error after registration is ≤0.02mm.

[0026] Furthermore, a 3D scanner with the required scanning accuracy is selected to ensure accurate capture of the spherical information of the ball screw and the glued ball, and the point cloud density is sufficient to support subsequent data processing. The preset coordinate system is set as the design reference coordinate system of the structural component, with the key machining surface of the structural component as the XY plane and the axis of the key machining hole as the Z axis, to ensure that the coordinate reference is consistent with the machining requirements. When registering the point cloud data with the design model, an iterative nearest point algorithm is used to optimize the registration effect through algorithm iteration, so that the error after registration is controlled within a reasonable range, ensuring that the obtained sphere center coordinates are accurate and reliable.

[0027] Step 1.3: The computer-aided software is CAD / CAM integrated software, which has coordinate transformation, program compilation and simulation functions; the format of the point-to-point program is matched with the control system of the CNC machine tool. If the CNC machine tool is a FANUC system, the point-to-point program adopts G-code format; if it is a SIEMENS system, the point-to-point program adopts M-code format; the point-to-point program also includes safety movement instructions, which set the safety distance when the CNC machine tool spindle drives the positioning component to move. The safety distance is the minimum distance between the positioning component and the large-sized irregular structural parts and the machine tool platform ≥ 50mm.

[0028] Furthermore, CAD / CAM integrated software with coordinate transformation, program compilation, and simulation functions is selected. First, the coordinates of the spherical screw center are converted into coordinates that conform to the machine tool coordinate system parameters. Then, it is compiled into a point-to-point program that matches the CNC machine tool control system. If the machine tool is a FANUC system, the G-code format is used, and if it is a SIEMENS system, the M-code format is used. At the same time, a safety movement instruction is added to the program to set the minimum safe distance between the spindle and the structural components and the machine tool platform when the spindle drives the positioning component to move, so as to avoid collisions during the movement.

[0029] Step 1.4: The quick positioning rod is made of 40Cr material, with a nitrided surface. The nitrided layer thickness is 0.15mm~0.3mm, and the surface hardness is HV550~HV650. The quick positioning rod is connected to the spindle tool sleeve by a tapered fit with a taper of 7:24 and a fit clearance ≤0.003mm. The fastening nut is made of 304 stainless steel with an internal thread accuracy grade of 5H, and the coaxiality error between the inner hole of the nut and the outer circle of the spherical adapter block is ≤0.01mm.

[0030] Furthermore, the quick-positioning rod is made of 40Cr material and its surface is nitrided to improve hardness and wear resistance. The quick-positioning rod and the CNC machine tool spindle sleeve adopt a tapered fit to ensure that the coaxiality of the two axes meets the requirements after the fit. The fastening nut is made of 304 stainless steel, and its internal thread accuracy level meets the standard. The coaxiality error between the inner hole of the nut and the outer circle of the spherical adapter block is controlled within a reasonable range. When the fastening nut is used to lock the spherical adapter block and the quick-positioning rod, it can be ensured that there is no relative displacement between the two.

[0031] Step 1.5, the movable support assembly further includes fastening screws, which are used to connect the spherical adapter block and the hydraulic support. The fastening screws are M12×30, made of high-strength alloy steel 12.9 grade, and have a tightening torque of 80N・m~100N・m. The inner spherical radius of the spherical adapter block is consistent with the outer spherical radius of the quick positioning rod, with a tolerance of ±0.002mm. The inner spherical surface is polished, with a roughness Ra≤0.4μm.

[0032] Furthermore, in the connection step between the positioning component and the support component, the spherical adapter block of the movable support component is connected to the hydraulic support by a fastening screw. This screw provides stable connection strength, ensuring that the two will not loosen during subsequent use. The inner spherical radius of the spherical adapter block is consistent with the outer spherical radius of the quick positioning rod, and the inner spherical surface is polished to reduce surface roughness, so that the spherical adapter block and the quick positioning rod can fit tightly together, ensuring subsequent positioning accuracy.

[0033] Step 1.6: The hydraulic support is a single-acting hydraulic jack with a rated support force ≥50kN, a telescopic stroke of 50mm~150mm, and a telescopic accuracy of ≤0.005mm; the locking mechanism is a hydraulic lock, and the pressure holding time of the hydraulic support after locking is ≥24h, with a pressure attenuation of ≤5%; the surface roughness Ra of the CNC machine tool platform is ≤0.8μm, the flatness error is ≤0.01mm / m, and the contact area between the movable support component and the machine tool platform is ≥90% of the bottom area of ​​the hydraulic support.

[0034] Furthermore, during the positioning and clamping steps of the support components, the hydraulic support used can provide sufficient support force and the telescopic accuracy meets the requirements, allowing for precise adjustment of the support height. The locking mechanism of the hydraulic support is a hydraulic lock, which can maintain pressure for a long time after locking with minimal pressure decay, ensuring the stability of the support position after locking. The surface roughness and flatness of the CNC machine tool platform meet the standards, ensuring that the contact area between the bottom of the hydraulic support and the platform meets the requirements, providing a stable support foundation for the support components, thereby ensuring the accuracy of the support components after positioning and clamping.

[0035] Step 1.7: The hoisting is carried out using a bridge crane with a hoisting accuracy of ≤0.1mm. During the hoisting process, the swing amplitude of the large-sized irregular structural component is controlled to be ≤5mm by a guide mechanism. The auxiliary clamping mechanism is a manual clamping wrench with a clamping force of 500N~800N. After clamping, the clamping torque is detected by a torque wrench to ensure that the torque value is stable within the preset range of ±5%. The outer spherical surface roughness Ra of the ball screw is ≤0.4μm, and the sphericity error is ≤0.003mm.

[0036] Furthermore, a bridge crane is used to lift large-sized irregular structural components. The crane's lifting accuracy meets the requirements and can precisely control the lifting position of the structural components. During the lifting process, a guide mechanism limits the swing amplitude of the structural components to prevent them from swinging and colliding with other parts. The auxiliary clamping mechanism uses a manual clamping wrench, which can provide appropriate clamping force during clamping. After clamping, a torque wrench is used to check the clamping torque to ensure that the torque is stable within the preset range, so that there is no relative displacement after the ball screw is fixed to the spherical adapter block. The surface roughness and sphericity error of the outer spherical surface of the ball screw meet the requirements, ensuring that it can fit tightly with the inner spherical surface of the spherical adapter block.

[0037] Step 1.8: The 3D scanner parameters for the second scan are consistent with those in Step 2. The temperature of the scanning environment is controlled at 20℃±2℃, and the humidity is controlled at 40%~60% to avoid airflow interference. The coordinate comparison uses professional measurement software with deviation analysis and graphical display functions, which can generate a deviation report. The deviation report includes the X-axis deviation, Y-axis deviation, Z-axis deviation, and total deviation of each adhesive ball. The hydraulic support is adjusted using a micro-adjustment method, with each adjustment amount being 0.001mm~0.005mm. After adjustment, the system is left to stand for 5 minutes before scanning verification.

[0038] Furthermore, during the alignment verification step, the parameters of the 3D scanner used for the second scan of the adhesive balls are kept consistent with the first scan to ensure the comparability of the two scan data. The scanning environment is controlled with temperature and humidity within a suitable range, and airflow interference is avoided to reduce the impact of environmental factors on scanning accuracy. Coordinate comparison uses professional measurement software with deviation analysis and graphical display functions, which can clearly present the deviation of each adhesive ball and generate a deviation report. When adjusting the hydraulic support, a micro-adjustment method is used, and after each adjustment, the system is allowed to stand for a period of time before scanning and verification to avoid errors caused by frequent adjustments and to ensure that the center coordinate deviation of all adhesive balls meets the requirements after adjustment.

[0039] The process also includes step 1.9: post-alignment maintenance and device recovery. After the large-sized irregular structural parts are aligned and qualified, the locking status of the movable support assembly is checked regularly during the processing, once every 2 hours, to ensure there is no loosening. After processing, the auxiliary clamping mechanism of the movable support assembly is removed first, then the locking mechanism of the hydraulic support is released, and the hydraulic support is retracted to its initial position. The connection between the spherical adapter block and the quick positioning rod is then removed. The spherical screws are cleaned to remove surface oil. If the threads are intact, they can be used for the alignment of the next large-sized irregular structural part of the same type. The spherical structure of the movable support assembly is cleaned, rust-preventive oil is applied, and it is stored in a special toolbox for later use. The rust-preventive oil is an extreme pressure rust-preventive oil with a rust prevention period of ≥12 months.

[0040] Furthermore, after the alignment work is completed, the machining stage begins. The locking status of the movable support assembly is checked at regular intervals to prevent loosening during machining and affecting machining accuracy. After the structural component is machined, the auxiliary clamping mechanism of the movable support assembly is removed first, then the locking mechanism of the hydraulic support is released, and the hydraulic support is retracted to its initial position. The connection between the spherical adapter block and the quick-positioning rod is then removed. The ball screws are cleaned to remove surface oil; if the threads are intact, they are kept for alignment of the next similar structural component. After cleaning the spherical structure of the movable support assembly, extreme pressure rust-preventive oil is applied, and it is then stored in a special toolbox for later use.

[0041] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for rapid alignment during machining of large-sized irregularly shaped structural parts, characterized in that, Includes the following steps: Step 1: Mounting of reference components. Positioning and verification reference components are mounted on the large-sized irregular-shaped structural component to be processed. The positioning reference component is a ball screw, and the verification reference component is an adhesive ball. At least four ball screws are installed, and their positions are not collinear. Each ball screw is threaded onto a process block or excess material of the large-sized irregular-shaped structural component. The excess material is reserved material that will not affect subsequent processing of the large-sized irregular-shaped structural component. At least four adhesive balls are installed, and each adhesive ball is glued to the outer surface of the large-sized irregular-shaped structural component, with the glued positions of all adhesive balls evenly distributed on different sides of the large-sized irregular-shaped structural component. Step 2: 3D scanning and coordinate acquisition. A 3D scanner is used to perform a full-range scan on the large-sized irregular-shaped structural component with ball screws and adhesive balls installed, acquiring point cloud data containing the spherical surfaces of all ball screws and adhesive balls. Based on the design model of the large-sized irregular-shaped structural component, the point cloud data is registered with the design model, and the spatial coordinates of the centers of all ball screws and adhesive balls in the preset coordinate system are obtained when the large-sized irregular-shaped structural component is in the theoretical processing posture. These coordinates are recorded as the ball screw center coordinates and adhesive ball center coordinates, respectively. Step 3: Point program generation. The ball center coordinates of the spherical screws obtained in Step 2 are imported into the computer-aided software. The computer-aided software converts the ball center coordinates of the spherical screws into a point program that can be recognized by the CNC machine tool according to the coordinate system parameters of the CNC machine tool. The point program includes the X-axis coordinates, Y-axis coordinates, and Z-axis coordinates of the support point corresponding to each spherical screw in the machine tool coordinate system, as well as the attitude adjustment parameters when the positioning component and the support component cooperate. The attitude adjustment parameters include the rotation angle of the positioning component around the X-axis and the rotation angle around the Y-axis. Step 4: Connect the positioning component and the support component. Make a detachable connection between the quick-positioning rod and the spindle sleeve of the CNC machine tool. After connection, ensure that the coaxiality error between the axis of the quick-positioning rod and the axis of the CNC machine tool spindle is ≤0.005mm. Connect the spherical adapter block of the movable support component to the quick-positioning rod using a spherical fit. The inner spherical surface of the spherical adapter block fits against the outer spherical surface of the quick-positioning rod, with a fit gap ≤0.02mm. Lock the spherical adapter block and the quick-positioning rod together using a fastening nut. The internal thread of the fastening nut engages with the external thread of the spherical adapter block. After locking, ensure that there is no relative displacement between the spherical adapter block and the quick-positioning rod. Step 5: Position and clamp the support assembly. Start the CNC machine tool and call the point program generated in Step 3. The CNC machine tool drive spindle to move the quick positioning rod and the movable support assembly connected to it to the support point corresponding to the first ball screw. Control the hydraulic support of the movable support assembly to stretch naturally until the bottom of the hydraulic support is in complete contact with the CNC machine tool platform. Lock the hydraulic support through the locking mechanism of the hydraulic support. After locking, the axial displacement of the hydraulic support is ≤0.01mm. Control the CNC machine tool spindle to separate the quick positioning rod from the spherical adapter block to complete the positioning and clamping of the first movable support assembly. Repeat Step 4 and Step 5 to complete the positioning and clamping of the movable support assemblies corresponding to all remaining ball screws in sequence. After the positioning of all movable support assemblies is completed, the support surfaces of each movable support assembly are on the same theoretical plane with a flatness error of ≤0.03mm. Step 6: Part installation and positioning. Hoist the large-sized irregular structural parts onto the CNC machine tool platform, aligning each ball screw on the large-sized irregular structural parts with the corresponding spherical adapter block of the movable support assembly. Slowly enlarge the size of the irregularly shaped structural component so that the outer spherical surface of each ball screw fits into the inner spherical surface of the corresponding spherical adapter block. After fitting, the ball screw and the spherical adapter block are fixed by the auxiliary clamping mechanism of the movable support assembly. After fixing, the relative displacement between the ball screw and the spherical adapter block is ≤0.008mm. Step 7: Verify the alignment status. Use a 3D scanner again to scan all the adhesive balls on the large-sized irregular-shaped structural component to obtain the actual center coordinates of each adhesive ball. Compare the actual center coordinates with the center coordinates of the adhesive balls obtained in Step 2 and calculate the coordinate deviation value of each adhesive ball center. If the coordinate deviation value of all adhesive balls is ≤0.05mm, the large-sized irregular-shaped structural component is considered to be aligned successfully. If there are adhesive balls with a coordinate deviation value >0.05mm, adjust the extension and retraction of the hydraulic bracket of the movable support component at the corresponding position until the coordinate deviation value of all adhesive balls is ≤0.05mm, thus completing the rapid alignment of the large-sized irregular-shaped structural component.

2. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 1, the thread specification of the ball screw matches the thread hole specification of the large-size irregular structural component process block or excess raw material, and the thread fit accuracy grade is 6H / 5g; the adhesive is a high-strength anaerobic adhesive with a shear strength ≥20MPa and no significant performance degradation in the temperature range of -20℃ to 80℃; the adhesive ball is made of stainless steel with a surface roughness Ra≤0.8μm and a sphericity error ≤0.005mm.

3. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 2, the scanning accuracy of the 3D scanner is ≤0.01mm, and the scanning point cloud density is ≥5 points per square millimeter; the preset coordinate system is the design reference coordinate system for large-sized irregular structural parts, with the key machining surface of the large-sized irregular structural parts as the XY plane and the axis of the key machining hole as the Z axis; the registration of the point cloud data and the design model adopts the iterative nearest point algorithm, and the root mean square error after registration is ≤0.02mm.

4. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 3, the computer-aided software is CAD / CAM integrated software, which has coordinate transformation, program compilation and simulation functions; the format of the point-to-point program is matched with the control system of the CNC machine tool. If the CNC machine tool is a FANUC system, the point-to-point program adopts G-code format; if it is a SIEMENS system, the point-to-point program adopts M-code format; the point-to-point program also includes safety movement instructions, which set the safety distance when the CNC machine tool spindle drives the positioning component to move. The safety distance is the minimum distance between the positioning component and the large-sized irregular structural parts and the machine tool platform ≥ 50mm.

5. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 4, the quick positioning rod is made of 40Cr material, with a nitrided surface, a nitrided layer thickness of 0.15mm~0.3mm, and a surface hardness of HV550~HV650; the quick positioning rod is connected to the spindle tool sleeve by a tapered fit with a taper of 7:24 and a fit clearance ≤0.003mm; the fastening nut is made of 304 stainless steel, with an internal thread accuracy grade of 5H, and the coaxiality error between the inner hole of the nut and the outer circle of the spherical adapter block is ≤0.01mm.

6. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 4, the movable support assembly also includes fastening screws. The fastening screws are used to connect the spherical adapter block and the hydraulic support. The fastening screws are M12×30, made of high-strength alloy steel 12.9 grade, and have a tightening torque of 80 N·m to 100 N·m. The inner spherical radius of the spherical adapter block is consistent with the outer spherical radius of the quick positioning rod, with a tolerance of ±0.002 mm. The inner spherical surface is polished, and the roughness Ra≤0.4 μm.

7. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 5, the hydraulic support is a single-acting hydraulic jack with a rated support force ≥50kN, a telescopic stroke of 50mm~150mm, and a telescopic accuracy of ≤0.005mm; the locking mechanism is a hydraulic lock, and the pressure holding time of the hydraulic support after locking is ≥24h, and the pressure decay is ≤5%; the surface roughness Ra of the CNC machine tool platform is ≤0.8μm, the flatness error is ≤0.01mm / m, and the contact area between the movable support component and the machine tool platform is ≥90% of the bottom area of ​​the hydraulic support.

8. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 6, the hoisting is carried out using a bridge crane with a hoisting accuracy of ≤0.1mm. During the hoisting process, the swing amplitude of the large-sized irregular structural component is controlled to be ≤5mm by a guide mechanism. The auxiliary clamping mechanism is a manual clamping wrench with a clamping force of 500N~800N. After clamping, the clamping torque is detected by a torque wrench to ensure that the torque value is stable within a preset range of ±5%. The outer spherical surface roughness Ra of the ball screw is ≤0.4μm, and the sphericity error is ≤0.003mm.

9. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, In step 7, the 3D scanner parameters for the second scan are kept consistent with those in step 2. The temperature of the scanning environment is controlled at 20℃±2℃, and the humidity is controlled at 40%~60% to avoid airflow interference. The coordinate comparison uses professional measurement software with deviation analysis and graphical display functions, which can generate a deviation report. The deviation report includes the X-axis deviation, Y-axis deviation, Z-axis deviation, and total deviation of each adhesive ball. The hydraulic support is adjusted using a micro-adjustment method, with each adjustment amount being 0.001mm~0.005mm. After adjustment, the system is left to stand for 5 minutes before scanning verification.

10. The method for rapid alignment during machining of large-size irregularly shaped structural parts according to claim 1, characterized in that, The process also includes step 8: post-alignment maintenance and device recovery. After the large-sized irregular structural parts are aligned and qualified, the locking status of the movable support components is checked regularly during the processing, once every 2 hours, to ensure there is no loosening. After processing, the auxiliary clamping mechanism of the movable support components is removed first, then the locking mechanism of the hydraulic support is loosened, the hydraulic support is retracted to the initial position, and the connection between the spherical adapter block and the quick positioning rod is removed. The spherical screws are cleaned to remove surface oil. If the threads are intact, they can be used for the alignment of the next large-sized irregular structural parts of the same type. The spherical structure of the movable support components is cleaned, rust-preventive oil is applied, and it is stored in a special toolbox for later use. The rust-preventive oil is an extreme pressure rust-preventive oil with a rust prevention period of ≥12 months.

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