Adjustable grinding head numerical control grinding machine and its adjustment precision control method

Abstract

The application discloses a numerical control grinding machine with adjustable grinding head and relates to the technical field of numerical control machine tools, which comprises a bed body, wherein a numerical control system, an adjustable grinding head assembly, an adjustable clamping assembly and a feeding driving assembly are arranged on the bed body, the adjustable grinding head assembly comprises a grinding head base, a grinding head body, an angle adjusting mechanism and an electric telescopic rod, the angle adjusting mechanism is matched with a worm and a gear through first and second servo motors, thereby realizing swing and rotation adjustment of the grinding head body, the adjustable clamping assembly is provided with rotation and pitch adjusting mechanisms and is suitable for clamping special-shaped and conventional workpieces, angle sensors are arranged on each adjusting mechanism, and a closed loop control is formed with the numerical control system. The control system can import a three-dimensional model, automatically extract geometric parameters and calculate adjustment amount, clamping force and feeding speed, and realizes the collaborative action of multiple mechanisms. The application has high adjustment precision and strong adaptability and can effectively improve the grinding quality and machining stability of complex curved surface parts.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool technology, specifically to a CNC grinding machine with an adjustable grinding head and a method for controlling the adjustment accuracy thereon. Background Technology

[0002] In the machinery manufacturing industry, CNC grinding machines are key equipment for precision surface machining of parts, widely used in aerospace, automotive manufacturing, mold processing, and medical device fields to achieve high-precision dimensional finishing and surface finish improvement of metallic or non-metallic materials. Existing CNC grinding machines typically consist of a bed, spindle head, worktable, feed system, and CNC device. Their working principle involves the CNC system controlling the high-speed rotation of the grinding wheel spindle and the linear or rotary motion of the workpiece worktable to grind the workpiece surface according to a preset program trajectory. For irregularly shaped parts with complex curved surface features, existing technologies typically employ multi-axis CNC systems, using specialized fixtures to fix the workpiece. The geometry of the curved surface is approximated by controlling the coordinated movement of multiple coordinate axes. Some solutions also incorporate online measuring devices to assist in positioning.

[0003] However, in the existing technology, when faced with irregularly shaped parts with drastic curvature changes or extremely complex geometric structures, the same set of equipment is difficult to be compatible with the mixed processing requirements of conventional and irregularly shaped parts with different curvature characteristics, resulting in limited processing accuracy and insufficient adaptability. Summary of the Invention

[0004] The purpose of this invention is to provide a CNC grinding machine with an adjustable grinding head and a method for controlling its adjustment accuracy, aiming to solve the technical problems of difficult precision grinding of complex curved surface parts and incompatible machining of irregular-shaped parts and conventional parts.

[0005] The present invention is achieved through the following technical solution: The first aspect of this application provides a CNC grinding machine with an adjustable grinding head, including a bed, on which a CNC control system, an adjustable grinding head assembly, an adjustable clamping assembly, and a feed drive assembly are provided; The CNC control system is electrically connected to the adjustable grinding head assembly, the adjustable clamping assembly, and the feed drive assembly to control the action of each assembly. The adjustable grinding head assembly and the adjustable clamping assembly are slidably mounted on the bed, and the feed drive assembly drives the two to feed relative to each other. The adjustable grinding head assembly includes a grinding head base and a grinding head body mounted on the grinding head base. An angle adjustment mechanism and a height adjustment mechanism are provided between the grinding head base and the grinding head body. The angle adjustment mechanism includes an adjustment seat, a first servo motor, a worm gear, a worm wheel, and a second servo motor. The worm wheel and the first servo motor are housed in the adjustment seat. One end of the worm gear meshes with the worm wheel, and the other end is connected to the grinding head body. The first servo motor drives the worm wheel, thereby causing the grinding head body to rotate 0-90° around the horizontal axis. The second servo motor is connected to the rotation axis of the grinding head body, thereby driving the rotation axis to rotate and causing the grinding head body to rotate 0-360° around its own axis. The height adjustment mechanism includes an electric telescopic rod, which drives the grinding head body to move up and down. The adjustable clamping assembly includes a clamping base and a rotation adjustment mechanism, a pitch adjustment mechanism, and a clamping mechanism disposed on the clamping base. The rotation adjustment mechanism includes a third servo motor and a rotary table. The third servo motor can drive the rotary table to rotate continuously around the vertical axis from 0 to 360°. The pitch adjustment mechanism includes a fourth servo motor, a pitch axis, and a pitch support. The fourth servo motor drives the pitch support to pitch and rotate around the pitch axis in the range of 0 to 90°. The clamping mechanism includes a hydraulic chuck, a replaceable soft jaw, and a suction cup. The replaceable soft jaw is mounted on the hydraulic chuck, and the vacuum suction cup is mounted at the center of the pitch support. Angle sensors are installed on the angle adjustment mechanism, rotation adjustment mechanism, and pitch adjustment mechanism. The angle sensors are electrically connected to the CNC control system. The CNC control system includes a surface machining parameter calculation module. The module automatically extracts the surface geometric parameters based on the imported three-dimensional model of the workpiece and calculates the grinding head angle adjustment amount, height adjustment amount, clamping force, locking force, and feed speed.

[0006] In one optional embodiment, the adjustable grinding head assembly and the adjustable clamping assembly are respectively provided with electromagnetic locking mechanisms, the electromagnetic locking mechanisms including electromagnets, armatures, locking blocks and return springs; The electromagnet is fixedly installed on the grinding head seat or clamping seat. The armature is fixedly connected to the locking block. The return spring is sleeved between the locking block and the electromagnet. When the electromagnet is energized, it attracts the armature and drives the locking block to press against the corresponding sliding mating surface to achieve locking. When the power is off, the return spring pushes the locking block to reset and loosen. The CNC control system dynamically adjusts the current of the electromagnet according to the real-time grinding force to change the magnitude of the locking force.

[0007] In one optional embodiment, the CNC control system adopts a PLC programmable controller, which integrates a virtual simulation module and a process parameter library, supports direct import of 3D models, and has a built-in angle encoder. The virtual simulation module is used to verify the collision risk and trajectory of the imported machining path before machining.

[0008] In one optional embodiment, the adjustable clamping assembly is equipped with an online probe system for automatically measuring the actual position and orientation of the workpiece. The CNC control system performs coordinate system compensation based on the measurement results to eliminate clamping errors, with a compensation amount ≤0.002mm.

[0009] In one optional embodiment, the feed drive assembly includes a feed motor, a ball screw, and a guide rail. The feed motor drives the ball screw to rotate, thereby causing the grinding head seat and the clamping seat to move smoothly along the guide rail. The feed speed can be steplessly adjusted.

[0010] In one optional embodiment, the transmission ratio of the worm gear and worm wheel in the angle adjustment mechanism is 1:30-1:50, and the replaceable soft claw is made of brass, with the difference between the curvature of its contact surface and the curvature of the workpiece surface being ≤0.001mm.

[0011] In one optional embodiment, one end of the worm gear of the angle adjustment mechanism meshes with a worm wheel, and the other end is directly fixedly connected to the swing shaft of the grinding head body. Both the worm wheel and the worm gear are installed inside the adjustment seat, which is fixedly installed on the grinding head seat. The swing axis of the grinding head body around the horizontal axis is collinear with the central axis of the worm gear. By directly fixing one end of the worm gear to the swing shaft of the grinding head body, intermediate transmission connecting parts are eliminated, reducing the gap error and angle lag caused by the transmission links. This makes the angle adjustment of the grinding head body more precise and the response faster. Containing the worm wheel and the worm gear entirely inside the adjustment seat can seal and protect the transmission components, preventing dust and cutting fluid from entering, improving the service life and operational stability of the transmission mechanism. Keeping the swing axis of the grinding head body and the central axis of the worm gear collinear can eliminate transmission eccentricity, lateral force, and vibration, ensuring smooth movement and high positioning accuracy of the grinding head during the 0-90° angle adjustment process, thereby improving the machining accuracy and surface quality of complex curved surface grinding.

[0012] The second aspect of this application provides a method for adjusting the accuracy of a CNC grinding machine based on the above-mentioned first aspect solution, comprising the following steps: S1. Import the 3D model of the workpiece and automatically extract the geometric parameters of complex surfaces, including normal vector, curvature, and tangent inclination angle; S2. Calculate the processing path parameters: S2.1. Calculate the angle θ between the normal vector of the surface machining point and the direction vector of the grinding head axis. The formula is: , where n is the normal vector of the surface machining point and m is the direction vector of the grinding head axis; S2.2. Based on the radius of curvature R of the surface and the horizontal distance l from the contact point between the grinding head and the surface to the center of the surface, calculate the grinding head height adjustment amount h. The formula is: h=R-√(R²-l²); S2.3. Calculate the angular velocity Ω of the rotary table based on the workpiece rotation radius r and the target grinding linear velocity v. The formula is: v = Ω·r; S2.4. Based on the surface curvature k and the target clamping force requirement, calculate the clamping force F of the clamping mechanism. The formula is: F=(k+k_min)·k0·S, where k=1 / R is the surface curvature, k_min is a preset positive constant used to ensure that the clamping force is non-zero during plane machining, k0 is a preset clamping force coefficient, and S is the clamping contact area. S2.5. Calculate the locking force required by the electromagnetic locking mechanism based on the contact angle θ between the grinding force F_m and the grinding head and the workpiece. The formula is: F_lock ≥ F_m·sinθ; S2.6. Based on the surface curvature k and the basic feed rate v0, adaptively adjust the feed rate v_f of the feed drive component. The formula is: v_f = v0 / (1 + k), where k is the numerical value of the surface curvature in mm. -1 ; S3. The collision risk and machining trajectory of the machining path parameters calculated in step S2 are verified by the virtual simulation module built into the CNC control system. After the verification is passed, step S4 is executed. S4. Measure the actual position and orientation of the workpiece through the online probe system, calculate the clamping error compensation amount Δ, and control the CNC system to perform coordinate system compensation so that the compensation amount meets Δ≤0.002mm; S5. Based on all the parameters calculated in step S2 and the compensation results in step S4, control the grinding head angle adjustment mechanism, height adjustment mechanism, workpiece rotation and pitch mechanism, and feed drive assembly to coordinate their actions and achieve high-precision grinding of complex curved surfaces. S6. During the processing, the angle data of each adjustment mechanism is collected in real time by the angle sensor and compared with the preset parameters to realize closed-loop feedback adjustment and ensure the accuracy and stability of the processing process.

[0013] In an optional embodiment, in step S21, the action of the grinding head angle adjustment mechanism is controlled so that the matching error between the grinding head angle, the workpiece posture and the complex curved surface satisfies |θ-θ0|≤0.001°, where θ0 is the theoretical angle required for machining the complex curved surface.

[0014] In an optional embodiment, the closed-loop feedback adjustment in step S6 includes: comparing the angle data collected in real time by the angle sensor with the theoretical angle θ calculated in step S21; when the difference exceeds a preset threshold, the CNC control system automatically adjusts the first servo motor and / or the second servo motor to correct the grinding head posture.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention achieves full-process adaptive control for machining complex curved surfaces by constructing a hardware architecture comprising a multi-angle collaboratively adjustable grinding head assembly and a multi-dimensional attitude adjustment clamping assembly, combined with a CNC strategy based on automatic calculation of 3D model parameters. Specifically, the first and second servo motors drive the worm gear and rotary axis, enabling the grinding head to swing in the vertical plane and rotate around its own axis. Combined with the height adjustment of the electric telescopic rod, this ensures the grinding head can adjust to the optimal cutting posture in real time according to the surface normal vector and curvature. Simultaneously, the third and fourth servo motors drive the clamping assembly to achieve horizontal rotation and pitch adjustment of the workpiece. Combined with a combination of hydraulic chuck, replaceable soft jaws, and vacuum suction cups, the clamping force is dynamically calculated and applied based on the surface curvature, effectively preventing workpiece deformation or displacement caused by improper clamping. Furthermore, a closed-loop feedback loop is constructed using angle sensors to monitor and correct angular deviations of each axis in real time. Combined with virtual simulation verification and an online probe compensation mechanism, this further eliminates the risk of path interference and clamping errors. This effectively solves the problems of difficult precision grinding of complex curved surface parts and incompatibility between irregular and conventional parts, significantly improving the fit, stability and consistency of grinding operations, and meeting the diverse manufacturing needs of high-difficulty precision parts.

[0016] In summary, this invention, through the deep integration of flexible multi-degree-of-freedom hardware adjustment and intelligent parameter calculation in software, forms a high-precision grinding technology system with rapid response. This system not only ensures the processing quality under a single complex working condition but also achieves versatility and reliability in multiple scenarios. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the CNC grinding machine structure with adjustable grinding head according to the present invention; Figure 2 This is a schematic diagram of the internal structure of the adjustable grinding head assembly of the present invention; Figure 3 This is a schematic diagram of the internal structure of the adjustable clamping component of the present invention; Figure 4 This is a schematic diagram of the CNC control system of the present invention; Figure 5 This is a flowchart of the precision control method of the present invention.

[0018] The attached diagram shows the markings and corresponding component names: 1. Bed; 2. Adjustable grinding head assembly; 20. Grinding head holder; 21. Grinding head body; 22. Angle adjustment mechanism; 220. Adjustment seat; 221. First servo motor; 222. Worm gear; 223. Worm wheel; 224. Second servo motor; 23. Height adjustment mechanism; 3. Adjustable clamping assembly; 30. Rotation adjustment mechanism; 300. Third servo motor; 301. Rotary table; 31. Pitch adjustment mechanism; 310. Fourth servo motor; 311. Pitch axis; 312. Pitch support; 32. Clamping mechanism; 320. Hydraulic chuck; 321. Soft jaw; 322. Suction cup; 4. Feed drive assembly. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.

[0020] Example 1: In the machining of complex curved surface parts, especially in industries such as aerospace, precision mold making, and irregular-shaped parts manufacturing, the geometry of workpiece surfaces is often highly irregular and variable. Traditional CNC grinding machines typically only have simple linear feed or limited rotational functions, with limited ability to adjust the relative posture between the grinding head and the workpiece, making it difficult to adapt to the changes in the normal vector of complex curved surfaces. When dealing with surfaces with high curvature, large tilt angles, or multiple degrees of freedom, existing equipment often requires multiple clamping operations or relies on repeated trial cuts based on manual experience, resulting in low processing efficiency and difficulty in guaranteeing grinding accuracy and surface quality. Furthermore, conventional clamping devices are mostly rigidly fixed, lacking the ability to actively adjust the workpiece posture, which easily leads to problems such as unstable clamping or poor contact when processing irregular-shaped parts, limiting the versatility and automation level of the equipment.

[0021] Against this backdrop, this application provides a CNC grinding machine with an adjustable grinding head, aiming to achieve precise spatial alignment between the grinding head and the workpiece by constructing a multi-degree-of-freedom collaborative adjustment mechanism. This solution introduces a grinding head assembly with dual-degree-of-freedom angle and height adjustment functions, coupled with a clamping assembly capable of omnidirectional rotation and pitch, and integrates a CNC control system with automatic surface parameter calculation capabilities, forming a complete adaptive grinding solution to address the technical challenges of precise grinding of complex curved surface parts and compatible machining of irregularly shaped parts.

[0022] Based on the above issues, please refer to Figures 1-3 This application provides a CNC grinding machine with an adjustable grinding head, including a bed 1, on which a CNC control system, an adjustable grinding head assembly 2, an adjustable clamping assembly 3, and a feed drive assembly 4 are provided; The CNC control system is electrically connected to the adjustable grinding head assembly 2, the adjustable clamping assembly 3, and the feed drive assembly 4, and is used to control the action of each assembly. The adjustable grinding head assembly 2 and the adjustable clamping assembly 3 are slidably mounted on the bed 1, and the feed drive assembly 4 drives the two to feed relative to each other. The adjustable grinding head assembly 2 includes a grinding head seat 20 and a grinding head body 21 mounted on the grinding head seat 20. An angle adjustment mechanism 22 and a height adjustment mechanism 23 are provided between the grinding head seat 20 and the grinding head body 21. The angle adjustment mechanism 22 includes an adjustment seat 220, a first servo motor 221, a worm 222, a worm wheel 223, and a second servo motor 224. The worm wheel 223 and the first servo motor 221 are disposed in the adjustment seat 220. One end of the worm 222 meshes with the worm wheel 223, and the other end is connected to the grinding head body 21. The first servo motor 221 drives the worm wheel 223, thereby causing the grinding head body 21 to rotate around the horizontal axis in the range of 0-90°. The second servo motor 224 is connected to the rotation shaft of the grinding head body 21, thereby driving the rotation shaft to rotate and causing the grinding head body 21 to rotate around its own axis in the range of 0-360°. The height adjustment mechanism 23 includes an electric telescopic rod, which drives the grinding head body 21 to move up and down. The adjustable clamping assembly 3 includes a clamping seat and a rotation adjustment mechanism 30, a pitch adjustment mechanism 31 and a clamping mechanism 32 disposed on the clamping seat. The rotation adjustment mechanism 30 includes a third servo motor 300 and a rotary table 301. The third servo motor 300 can drive the rotary table 301 to rotate continuously around the vertical axis from 0 to 360°. The pitch adjustment mechanism 31 includes a fourth servo motor 310, a pitch axis 311 and a pitch support 312. The fourth servo motor 310 drives the pitch support 312 to pitch and rotate around the pitch axis 311 in the range of 0 to 90°. The clamping mechanism 32 includes a hydraulic chuck 320, a replaceable soft claw 321 and a suction cup 322. The replaceable soft claw 321 is mounted on the hydraulic chuck 320 and the vacuum suction cup 322 is mounted at the center of the pitch support 312. Angle sensors are installed on the angle adjustment mechanism 22, the rotation adjustment mechanism 30, and the pitch adjustment mechanism 31. The angle sensors are electrically connected to the CNC control system. The CNC control system includes a surface machining parameter calculation module. The module automatically extracts the surface geometric parameters based on the imported three-dimensional model of the workpiece and calculates the grinding head angle adjustment amount, height adjustment amount, clamping force, locking force, and feed speed.

[0023] The bed 1 can be made of cast iron, granite, or welded steel, serving as the supporting foundation for the entire equipment to bear the aforementioned functional components and maintain overall rigidity. The specific dimensions, shape, and internal rib structure of the bed 1 can be set according to actual machining stroke and load requirements; this embodiment does not impose any special limitations on these aspects. The bed 1 provides an installation reference for the CNC control system, adjustable grinding head assembly 2, adjustable clamping assembly 3, and feed drive assembly 4, ensuring the positional accuracy of each component during movement.

[0024] A CNC control system can refer to an industrial computer, a PLC (Programmable Logic Controller), or a dedicated CNC device, which integrates a processor, memory, and input / output interfaces. The function of a CNC control system is to receive externally input 3D model data of the workpiece, analyze its geometric features through built-in algorithms, and generate control commands to drive the actions of various actuators. The CNC control system can be electrically connected to the adjustable grinding head assembly 2, the adjustable clamping assembly 3, and the feed drive assembly 4 via bus, Ethernet, or hardwiring to achieve bidirectional signal transmission.

[0025] The adjustable grinding head assembly 2 is the core execution unit for performing grinding operations. It is configured to adjust the posture of the grinding head body 21 in multiple degrees of freedom in space. The adjustable grinding head assembly 2 is slidably mounted on the bed 1. It cooperates with the adjustable clamping assembly 3 and, driven by the feed drive assembly 4, achieves relative movement closer or further away, thereby completing the feed cutting.

[0026] The grinding head holder 20 can be a box structure fixed on a slide table, used to house some of the transmission components of the angle adjustment mechanism 22 and provide support. The grinding head body 21 can refer to a rotating spindle assembly with a grinding wheel or other grinding tools mounted on it, and its material can be high-strength alloy steel with a hardened surface. The grinding head holder 20 and the grinding head body 21 are kinematically connected through the angle adjustment mechanism 22 and the height adjustment mechanism 23, so that the grinding head body 21 has multi-directional adjustability relative to the grinding head holder 20.

[0027] An angle adjustment mechanism 22 is used to adjust the spatial angle and posture of the grinding head body 21. The angle adjustment mechanism 22 includes an adjustment seat 220, a first servo motor 221, a worm gear 222, a worm wheel 223, and a second servo motor 224. The adjustment seat 220 is fixed to the grinding head seat 20 and has an internal receiving cavity. The output shaft of the first servo motor 221 is connected to the worm wheel 223 or via a reducer, and the worm wheel 223 meshes with the worm gear 222 for transmission. One end of the worm gear 222 extends to the outside of the adjustment seat 220 and is connected to the swing shaft of the grinding head body 21. When the first servo motor 221 operates, it drives the worm wheel 223 to rotate, thereby causing the worm gear 222 and the grinding head body 21 to swing around a horizontal axis. The swing range can be 0-90°, which can be set according to actual processing requirements, for example, it can also be 0-120°. This embodiment of the application does not specifically limit this range. This worm wheel 223 and worm gear 222 transmission method has a self-locking characteristic, which can maintain the stability of the grinding head angle when power is off or the drive stops.

[0028] The second servo motor 224 is directly connected or connected via a coupling to the rotating shaft of the grinding head body 21, driving the grinding head body 21 to rotate at high speed around its own axis, with a rotation range of 0-360° continuous rotation. The main function of the second servo motor 224 is to provide the cutting speed required for grinding, while working with the first servo motor 221 to achieve arbitrary angular positioning of the grinding head in space. The cooperation between the first servo motor 221 and the second servo motor 224 gives the grinding head body 21 two degrees of freedom: oscillation around a horizontal axis and rotation around its own axis, enabling it to adapt to normal changes on complex curved surfaces.

[0029] The height adjustment mechanism 23 includes an electric telescopic rod, which can be an electric push rod, a linear module driven by a lead screw and nut pair, or a hydraulic cylinder. One end of the electric telescopic rod is fixed to the grinding head seat 20 or the adjusting seat 220, and the other end is connected to the grinding head body 21 or its support frame. The telescopic movement of the electric telescopic rod drives the grinding head body 21 to move up and down in the vertical direction, which is used to finely adjust the contact height between the grinding head and the workpiece to adapt to the machining requirements of curved surfaces with different radii of curvature. The stroke, thrust, and running speed of the electric telescopic rod can be set according to actual conditions, and this embodiment does not impose any special limitations on them.

[0030] The adjustable clamping assembly 3 is used to clamp the workpiece to be processed and has multi-degree-of-freedom posture adjustment capability. The adjustable clamping assembly 3 includes a clamping base, a rotation adjustment mechanism 30, a pitch adjustment mechanism 31, and a clamping mechanism 32. The clamping base is slidably mounted on the bed 1, serving as a motion base on the workpiece side.

[0031] The rotation adjustment mechanism 30 includes a third servo motor 300 and a rotary table 301. The third servo motor 300 is fixed on the clamping base, and its output shaft is connected to the rotary table 301, driving the rotary table 301 to rotate continuously from 0 to 360° around the vertical axis. The rotary table 301 carries the pitch adjustment mechanism 31 and the workpiece. By rotating around the vertical axis, the azimuth angle of the workpiece in the horizontal plane is changed, and the movement of the grinding head is coordinated to achieve the machining of helical lines or annular curved surfaces.

[0032] The pitch adjustment mechanism 31 includes a fourth servo motor 310, a pitch axis 311, and a pitch support 312. The fourth servo motor 310 is mounted on the rotary table 301 or an extension of the clamping seat, and drives the pitch axis 311 to rotate via gears, belts, or direct drive. The pitch support 312 is fixed to the pitch axis 311 and oscillates within a range of 0-90° as the pitch axis 311 rotates. The pitch support 312 is used to mount the clamping mechanism 32, and its oscillation action changes the tilt angle of the workpiece in the vertical plane, allowing the workpiece surface to maintain optimal contact with the grinding head.

[0033] The clamping mechanism 32 includes a hydraulic chuck 320, replaceable soft jaws 321, and a suction cup 322 (i.e., a vacuum suction cup 322). The hydraulic chuck 320 is mounted on the pitch support 312 and is used to clamp workpieces hydraulically. The replaceable soft jaws 321 are installed at the jaw position of the hydraulic chuck 320. Their material can be brass, aluminum alloy, or engineering plastic, and the curvature of the contact surface can be customized or replaced according to the curvature of the workpiece surface to ensure that the clamping surface fits snugly against the workpiece surface, preventing damage to the workpiece surface and improving clamping stability. The suction cup 322 is installed at the center or a specific position of the pitch support 312 and uses vacuum negative pressure to adsorb flat or flat workpieces. The combined use of the hydraulic chuck 320 and the suction cup 322 allows this clamping assembly to clamp both rotating irregularly shaped parts and flat, conventional parts, enhancing the equipment's compatibility.

[0034] Angle sensors are installed at key rotating parts of the angle adjustment mechanism 22, rotation adjustment mechanism 30, and pitch adjustment mechanism 31, such as the output shafts or drive chain ends of the first servo motor 221, second servo motor 224, third servo motor 300, and fourth servo motor 310. The angle sensors can be photoelectric encoders, magnetic encoders, etc., used to collect the actual rotation angle data of each axis in real time and feed the data back to the CNC control system. The electrical connection between the angle sensors and the CNC control system forms a closed-loop control circuit, ensuring the operational accuracy of each adjustment mechanism.

[0035] The surface machining parameter calculation module included in the CNC control system automatically extracts the geometric parameters of each machining point on the surface, including normal vectors, curvature, and tangent inclination angles, based on the imported 3D workpiece model (such as STL or STEP format). Based on these geometric parameters, the module uses a preset algorithm to calculate process parameters such as grinding head angle adjustment, height adjustment, clamping force, locking force, and feed rate. For example, it calculates the required angle compensation value based on the angle between the surface normal vector and the grinding head axis, and calculates the height adjustment based on the radius of curvature. The calculation results of this module are directly sent as control commands to each servo motor and actuator, realizing automated conversion from model to machining action.

[0036] The core innovation of this application lies in the construction of a grinding system that enables bidirectional, multi-degree-of-freedom coordinated adjustment between the grinding head and the workpiece. The angle adjustment mechanism 22 enables the oscillation and rotation of the grinding head body 21, which, combined with the lifting and lowering actions of the height adjustment mechanism 23 and the rotation and pitch adjustments of the clamping components, forms a five-axis linkage machining capability. Simultaneously, by utilizing the automatic surface parameter calculation function of the CNC control system, the complex geometric solution process is integrated, achieving automatic generation of machining parameters and closed-loop feedback control.

[0037] The working process and principle of this application are as follows: First, the three-dimensional model of the workpiece is imported into the CNC control system. The surface machining parameter calculation module analyzes the model and extracts geometric features to calculate the target position and process parameters of each motion axis. Subsequently, the CNC control system drives the first servo motor 221 and the second servo motor 224 to adjust the spatial posture of the grinding head body 21 and drives the electric telescopic rod to adjust the height of the grinding head. At the same time, it drives the third servo motor 300 and the fourth servo motor 310 to adjust the rotation angle and pitch angle of the workpiece, so that the grinding surface of the grinding head body 21 is consistent with the normal direction of the workpiece surface to be machined or forms a preset angle. During the machining process, the angle sensor monitors the angle of each axis in real time and provides feedback. The CNC control system makes corrections based on the feedback data, and the feed drive component 4 drives the grinding head component and the clamping component to move relative to each other to complete high-precision grinding.

[0038] As a preferred embodiment, the solution of this application is specifically implemented as follows: Assume the workpiece to be machined is an aircraft blade with a complex free-form surface. The operator imports the blade's 3D CAD model into the CNC control system. The surface machining parameter calculation module automatically identifies the curvature changes on the blade surface and calculates the required grinding head angles at different positions from the blade root to the blade tip.

[0039] The system controls the third servo motor 300 to drive the rotary table 301 to rotate, so that the blade moves to the processing area; and controls the fourth servo motor 310 to drive the pitch support 312 to swing, thereby adjusting the blade tilt angle.

[0040] Meanwhile, the first servo motor 221 drives the worm gear 223 and worm 222 mechanism to make the grinding head body 21 swing around the horizontal axis to an angle consistent with the normal of the blade surface; the second servo motor 224 starts to drive the grinding head to rotate at high speed; the electric telescopic rod finely adjusts the height of the grinding head to ensure that the grinding depth meets the requirements.

[0041] The hydraulic chuck 320, in conjunction with the replaceable soft jaws 321 customized according to the curvature of the blade root, clamps the workpiece. The angle sensor transmits the angle of each axis back in real time. If a deviation is detected, the system automatically adjusts the output of the servo motor.

[0042] The feed drive assembly 4 drives the grinding head to move smoothly along the blade profile, completing the precision grinding of the entire curved surface. During this process, if a region of abrupt curvature change is encountered, the system automatically adjusts the feed speed and clamping force to ensure machining quality.

[0043] Through the above technical solutions, this application achieves the following beneficial effects: The use of an adjustable grinding head assembly 2 with dual-degree-of-freedom angle and height adjustment, and an adjustable clamping assembly 3 with rotation and pitch adjustment functions, enables multi-dimensional posture adaptation between the grinding head and the workpiece, thus solving the problem of traditional equipment's inability to handle complex surface normal changes and significantly improving grinding fit. The clamping mechanism 32 employs a combination structure of a hydraulic chuck 320 with replaceable soft jaws 321 and a vacuum suction cup 322, and the curvature of the soft jaws 321 can be customized, thus accommodating the clamping requirements of both irregular and conventional parts, expanding the equipment's applicability. Furthermore, each adjustment mechanism is equipped with an angle sensor and forms a closed loop with the CNC system, and the system's built-in surface machining parameter calculation module can automatically calculate geometric parameters, thereby reducing manual intervention, improving the calculation accuracy and response speed of machining parameters, and ensuring high-precision and high-efficiency grinding of complex curved surface parts.

[0044] Example 2: In an optional embodiment, this application further defines a CNC grinding machine with an adjustable grinding head according to the above embodiments, wherein the adjustable grinding head assembly 2 and the adjustable clamping assembly 3 are respectively provided with an electromagnetic locking mechanism, the electromagnetic locking mechanism including an electromagnet, an armature, a locking block and a return spring; The electromagnetic locking mechanism refers to a mechanical and electrical composite component used to rigidly lock the sliding mating surfaces during grinding to prevent displacement. In this design, the electromagnetic locking mechanism functions to provide a dynamically adjustable holding force to counteract vibrations or cutting reactions generated during machining. The electromagnetic locking mechanism has a direct physical connection and action-operation relationship with the adjustable grinding head assembly 2 and the adjustable clamping assembly 3. It restricts the relative degrees of freedom of the components by pressing against the sliding mating surfaces, thereby forming a stable machining reference state.

[0045] An electromagnet can be defined as an actuator that generates a magnetic field when energized to drive mechanical movements. The electromagnet is fixedly mounted on the grinding head holder 20 or the clamping seat, serving as the power source for the electromagnetic locking mechanism. In this embodiment, the electromagnet is electrically connected to the CNC control system and receives current control signals from it. The function of the electromagnet is to convert electrical energy into magnetic attraction, thereby driving the armature to move. Depending on the actual working conditions, the model, power, and installation position of the electromagnet can be set according to the actual situation; for example, it can be a DC electromagnet or an AC electromagnet. This embodiment does not impose any special limitations on this.

[0046] An armature is a magnetically conductive component that undergoes linear displacement under the influence of a magnetic field. The armature is fixedly connected to the locking block, forming a linked unit. When the electromagnet is energized and generates magnetic force, the armature is attracted and moves towards the electromagnet, simultaneously causing the locking block to move synchronously. The armature's role in the electromagnetic locking mechanism is to transmit magnetic force to the locking block, realizing the conversion from electromagnetic drive to mechanical clamping. The armature can be made of soft magnetic material, and its shape and size can be adaptively adjusted according to the electromagnet's magnetic circuit design and installation space.

[0047] A locking block can refer to a contact component that directly acts on a sliding mating surface to generate frictional resistance. Driven by an armature, the locking block presses against the corresponding sliding mating surface (e.g., the contact surface between a guide rail and a slider), thereby locking the sliding mating surface. The fit between the locking block and the sliding mating surface determines the locking effect. The contact surface can be set to a flat surface, an arc surface, or a surface with anti-slip texture, depending on the actual situation. The material can be a high-friction coefficient and wear-resistant material, such as bronze-based composite materials or polymer materials; this application does not impose any special limitations on this. The locking block increases the normal pressure between the sliding mating surfaces, thereby increasing the static friction and suppressing fretting displacement.

[0048] A return spring is an elastic element that provides a restoring force to release the locking state after the electromagnet is de-energized. The return spring is sleeved between the locking block and the electromagnet, and is in a pre-stored energy state of compression or tension (depending on the installation structure). When the electromagnet is de-energized and loses its magnetic force, the return spring releases its elastic potential energy, pushing the locking block and armature back to their original positions, disengaging them from the pressing state with the sliding mating surface, thereby achieving release. The stiffness coefficient of the return spring can be set according to the required reset speed and initial preload; for example, it can be a helical compression spring or a disc spring, and this application does not impose any special limitations on this.

[0049] Specifically, the working process and principle of this application are as follows: When the adjustable grinding head assembly 2 or the adjustable clamping assembly 3 is adjusted to the target position, the CNC control system sends an energizing signal to the electromagnet. The electromagnet generates magnetic force to attract the armature. The armature drives the locking block to overcome the elastic force of the return spring and move towards the sliding mating surface and press it. At this time, the assembly is rigidly locked and cannot slide relative to the feed direction. During the grinding process, if the grinding force changes in real time, the CNC control system dynamically adjusts the current flowing through the electromagnet according to the preset control strategy, thereby changing the magnitude of the magnetic attraction force, and then linearly or nonlinearly adjusting the clamping force of the locking block on the sliding mating surface, so that the clamping force is always slightly greater than or equal to the current grinding disturbance resultant force, which prevents loosening and avoids guide rail deformation due to excessive clamping force. When it is necessary to readjust the assembly position, the CNC control system cuts off the power supply to the electromagnet, the return spring pushes the locking block to reset and release, and the assembly restores its sliding freedom.

[0050] As a preferred embodiment, the solution of this application is implemented as follows: During complex surface grinding, the workpiece is fixed on the adjustable clamping assembly 3, and the grinding head is mounted on the adjustable grinding head assembly 2. When the feed drive assembly 4 drives the two to move relative to each other to a certain machining point and stops feeding, the CNC control system immediately activates the electromagnetic locking mechanism set on the grinding head seat 20 and the electromagnetic locking mechanism set on the clamping seat. The electromagnet is energized, attracting the armature and driving the locking block to press tightly against the side of the guide rail. At this time, if the grinding head body 21 applies a large lateral grinding force to the workpiece, this force attempts to push the grinding head seat 20 to make a slight displacement, but is balanced by the huge static friction force generated by the electromagnetic locking mechanism. At the same time, the force sensor monitors the magnitude of the grinding force in real time and feeds the data back to the CNC control system. If a sudden increase in grinding force is detected (e.g., encountering a hard point), the CNC control system instantly increases the current of the electromagnet to increase the locking force to prevent slippage; if the grinding force decreases, the current is reduced accordingly to save energy and reduce heat generation. After processing is completed, the electromagnet is de-energized, the return spring pushes the locking block back, and the equipment enters the rapid idle movement state.

[0051] Through the above technical solution, this application achieves a reliable locking mechanism for the adjustable grinding head assembly 2 and the adjustable clamping assembly 3 in the machining position by setting an electromagnetic locking mechanism composed of an electromagnet, an armature, a locking block, and a return spring. This effectively prevents minor displacement and vibration of the assemblies under high grinding force, thus improving machining accuracy. Since the CNC control system can dynamically adjust the energizing current of the electromagnet according to the real-time grinding force, adaptive matching of the locking force is achieved, avoiding the problems of over-locking damage to the guide rail or under-locking loss of accuracy caused by fixed locking force in traditional mechanical locking methods, thus balancing the rigidity and safety of the system.

[0052] Example 3: In one optional implementation, the CNC control system adopts a PLC programmable controller, which integrates a virtual simulation module and a process parameter library, supports direct import of 3D models, and has a built-in angle encoder. The virtual simulation module is used to verify the collision risk and trajectory of the imported machining path before machining.

[0053] In this context, a PLC (Programmable Logic Controller) is the core hardware unit of a CNC control system, used to execute instructions for logical operations, sequential control, timing, counting, and arithmetic operations. In this application, the PLC is electrically connected to the adjustable grinding head assembly 2, the adjustable clamping assembly 3, and the feed drive assembly 4. It receives feedback signals from the angle sensor and sends action commands to each servo motor and drive mechanism according to preset control logic to achieve precise and coordinated control of the grinding head angle, height, and workpiece posture. The specific model, brand, and processing speed of the PLC can be set according to the actual machining accuracy requirements and the on-site industrial environment.

[0054] A virtual simulation module refers to a software functional unit running within or connected to a CNC control system. Based on the equipment's kinematic model and imported workpiece 3D data, it constructs a digital twin environment in virtual space corresponding to the physical machine tool. The module's function is to pre-simulate the motion trajectories of the grinding head body 21, clamping components, and feed drive components 4 before actual physical actions occur. By calculating the spatial relationships of each component during movement, it identifies potential interference areas, overtravel risks, or collision points. The virtual simulation module works in conjunction with a PLC programmable controller. When a collision risk is detected, it can prevent the execution of machining instructions or prompt the operator to adjust the path, thus forming a safety mechanism of simulation before execution. Its implementation can be a dedicated simulation program developed based on OpenGL or DirectX graphics libraries, or a functional plug-in integrating a commercial simulation kernel.

[0055] A process parameter library refers to a database or data structure that stores optimized process strategies for various typical machining scenarios. Its content can include recommended grinding speeds, feed rates, depths of cut, coolant flow rates, and clamping force parameters for different materials (such as aluminum alloys, titanium alloys, and high-temperature alloys) and different surface types (such as freeform surfaces, helical surfaces, and spherical surfaces). The process parameter library is linked to the virtual simulation module and the surface machining parameter calculation module. After the system automatically extracts the geometric parameters of the workpiece's 3D model, it can call matching basic parameters from the process parameter library as initial values, and then fine-tune them based on real-time calculation results to reduce the trial-and-error costs of manually setting parameters. The data source for the process parameter library can be standard data accumulated through experiments in advance, or historical data manually entered by users based on actual machining experience. Its storage medium can be the PLC's internal non-volatile memory or an externally connected industrial database server.

[0056] An angle encoder can refer to a sensor device used to detect the angular displacement or angular velocity of a rotating shaft, which is built into a CNC control system or integrated with the servo drive unit in the system. In the present application, the angle encoder is mainly used to acquire the rotor position or output shaft angle of the first servo motor 221, the second servo motor 224, the third servo motor 300, and the fourth servo motor 310 in real time, and feed back the analog or digital signals to the PLC programmable controller to form a high-precision position closed-loop or speed closed-loop control loop. The type of angle encoder can be an incremental encoder or an absolute encoder, and the resolution can be selected according to the required angle control accuracy (e.g., 0.001°).

[0057] Specifically, the working process of this application is as follows: The operator first imports the 3D CAD model of the workpiece to be processed into the CNC control system. The system automatically parses the model data and extracts the surface geometric features. Then, the PLC programmable controller calls the basic strategy in the process parameter library and calculates the preliminary processing path in combination with the surface geometric parameters. Next, the virtual simulation module is started, using the built-in equipment kinematic model to simulate the entire process of the grinding head assembly and clamping assembly moving along the path. During this process, it judges in real time whether there is physical interference between parts or exceeding the mechanical limit. If the simulation verification is passed, the system sends the generated control commands to each actuator. At the same time, the angle encoder starts to monitor the actual position of each axis in real time to ensure that the motion trajectory is consistent with the planned path. If the simulation detects a collision risk, the system interrupts the process and alarms until the path is corrected and passes the verification again.

[0058] As a preferred embodiment, the solution of this application is implemented as follows: For the grinding of the complex curved surface of a certain aero-engine blade, the user imports the STEP format 3D model of the blade into the CNC control system. The system identifies that the blade surface contains areas with large curvature changes and thin-walled, easily deformable features, and then retrieves a processing strategy template suitable for thin-walled titanium alloy parts from the process parameter library. According to the strategy, the virtual simulation module simulates the relative motion of the grinding head oscillating within the range of 0-90° and the workpiece rotating within the range of 0-360°, and finds that there is a potential interference risk between the fixture and the grinding head seat 20 near the root of the blade in the original planned path. The system automatically marks the risk area and suggests adjusting the tilt angle of the grinding head. After the operator confirms the adjustment, the system re-performs the simulation verification. After confirming that there is no collision and the trajectory is smooth, the PLC programmable controller officially drives the first servo motor 221, the second servo motor 224 and the feed motor to perform the grinding action. During this period, the angle encoder provides real-time feedback of angle data with a resolution of 0.001° to ensure processing accuracy.

[0059] Through the above technical solution, this application achieves comprehensive collision risk prediction and trajectory verification of the imported processing path before actual processing by adopting a PLC programmable controller with integrated virtual simulation module and process parameter library. Therefore, it effectively avoids equipment collisions or workpiece scrap accidents caused by improper path planning, and significantly improves the safety and reliability of the processing process. At the same time, due to the built-in angle encoder and support for direct import of 3D models, it realizes the automated conversion from model data to control commands and high-precision closed-loop feedback, thereby reducing the time cost of manual programming and trial cutting, and improving the adaptability and processing efficiency of complex curved surface parts.

[0060] Example 4: In one optional embodiment, the adjustable clamping assembly 3 is equipped with an online probe system, which is used to automatically measure the actual position and orientation of the workpiece. The CNC control system performs coordinate system compensation based on the measurement results to eliminate clamping errors, with a compensation amount ≤0.002mm.

[0061] The online probe system can be a non-contact or contact measuring device integrated into the adjustable clamping assembly 3, whose function is to acquire the actual spatial coordinate data of the workpiece in the clamping state. This system can be installed in conjunction with the rotary table 301 or the pitch support 312 in the adjustable clamping assembly 3, for example, it can be installed on the side or center of the pitch support 312, or it can be independently installed on the bed 1 and extend to the clamping area. When working, the online probe system can send measurement signals containing the coordinates of key workpiece points, surface normal vectors, or contour features to the CNC control system. After receiving the signal, the CNC control system compares it with the theoretical coordinate data in the imported 3D model of the workpiece to calculate the deviation vector between the actual clamping position and the theoretical machining datum. This deviation vector can include translational components in the X, Y, and Z directions, as well as angular components of rotation around each axis. Through this cooperation, the online probe system and the CNC control system together form an error detection and compensation link, enabling the machining coordinate system to be dynamically updated based on the measured results, thereby controlling the datum offset caused by clamping within the range of ≤0.002mm. The embodiments of this application do not impose special limitations on the specific type of online probe system. For example, it can be a laser displacement sensor, a visual recognition camera, a trigger probe, or a scanning probe. It can be set according to the actual situation based on the workpiece material, surface characteristics, and accuracy requirements.

[0062] Specifically, the working process and principle of this application are as follows: After the workpiece is initially clamped, the CNC control system starts the online probe system and controls the probe to scan and measure specific feature points or contours of the workpiece; the actual position and attitude data collected by the probe are transmitted to the CNC control system; the internal algorithm of the control system matches the measured data with the pre-stored three-dimensional model theoretical data to calculate the current clamping error compensation amount; subsequently, the control system automatically corrects the origin position and axial angle of the machining coordinate system, so that the motion trajectory of the subsequent grinding head assembly is executed based on the corrected coordinate system, thereby logically offsetting the error caused by physical clamping and ensuring the precise fit between the grinding path and the actual surface of the workpiece.

[0063] As a preferred embodiment, the solution of this application is implemented as follows: After the irregular curved surface workpiece is fixed by the hydraulic chuck 320 or the vacuum suction cup 322, the CNC control system calls the online probe system to drive the probe to move along a preset path to multiple key detection points above the workpiece; the probe contacts or scans the workpiece surface in sequence and records the actual three-dimensional coordinates of each point; the system performs least squares fitting between the recorded actual coordinate set and the theoretical coordinate set in the CAD model to calculate the overall translational deviation and rotational deviation; if the calculated comprehensive deviation value exceeds the allowable threshold, the system automatically generates a compensation command to adjust the workpiece coordinate system parameters of the CNC system so that the compensated coordinate system coincides with the actual posture of the workpiece, and the compensation accuracy is controlled within 0.002mm; after the compensation is completed, the system locks the new coordinate system and starts the grinding process.

[0064] Through the above technical solution, this application achieves the ability to obtain the actual position and posture information of the workpiece after clamping in real time by setting up an online probe system and linking it with the CNC control system. Therefore, the machining coordinate system can be automatically corrected by software algorithm, eliminating the positioning error caused by inaccurate manual clamping, thereby achieving a high-precision machining effect with a compensation amount of ≤0.002mm. There is no need for repeated manual tool setting, which improves the automation level and dimensional consistency of machining complex curved surface parts.

[0065] Example 5: In an optional embodiment, this application further defines a CNC grinding machine with an adjustable grinding head according to the above embodiments. The feed drive assembly 4 includes a feed motor, a ball screw, and a guide rail. The feed motor drives the ball screw to rotate, thereby causing the grinding head holder 20 and the clamping seat to move smoothly along the guide rail. The feed speed can be steplessly adjusted.

[0066] The feed drive assembly 4 refers to a mechanical transmission unit that provides the relative linear motion power between the grinding head and the workpiece. Its function is to convert rotational motion into high-precision linear displacement to meet the continuously changing feed rhythm requirements during the machining of complex curved surfaces. This feed drive assembly 4 is linked with the aforementioned adjustable grinding head assembly 2 and adjustable clamping assembly 3, and material removal is achieved by changing the relative position between them.

[0067] The feed motor can be a servo motor or a stepper motor, serving as the power source and responsible for outputting rotational torque. The output shaft of the feed motor is connected to one end of the ball screw, and it precisely controls its speed and angle by receiving pulse signals or analog signals from the CNC control system. In this application, the speed of the feed motor directly determines the moving speed of the grinding head holder 20 or the clamping seat, and its cooperation with the ball screw realizes the conversion from electrical energy to mechanical linear motion. Depending on the actual processing scenario, the rated power, maximum torque, and other parameters of the feed motor can be set according to the actual situation; for example, it can be an AC servo motor or a DC brushless motor. This application embodiment does not impose any special limitations on this.

[0068] A ball screw is an ideal product that converts rotary motion into linear motion, or vice versa. It consists of a screw, a nut, and balls. The two ends of the ball screw are typically supported on the machine bed 1 by bearings, with one end connected to the feed motor. When the feed motor drives the ball screw to rotate, the nut mounted on the ball screw will undergo axial linear displacement. Due to the internal ball circulation structure, the ball screw has low frictional resistance, high transmission efficiency, and minimal backlash, ensuring the positioning accuracy of the grinding head holder 20 and the clamping seat during movement. The lead, diameter, and other specifications of the ball screw can be selected according to the required feed speed and load capacity.

[0069] A guide rail refers to a support element used to restrict the degrees of freedom of moving parts and guide their movement along a predetermined trajectory. The guide rail is fixedly mounted on the bed 1 and is arranged parallel to the ball screw. The bottom of the grinding head holder 20 and the clamping seat is equipped with sliders that cooperate with the guide rail, allowing the holder to move only along the length of the guide rail. The function of the guide rail is to bear the weight of the grinding head holder 20 and the clamping seat, as well as the radial force and overturning moment generated during grinding, ensuring the smoothness and straightness of the movement and preventing skewing or vibration caused by uneven force. The guide rail can be a linear rolling guide or a sliding guide; its length and number can be set according to the dimensions of the bed 1 and the stroke requirements.

[0070] Specifically, the working process and principle of this application are as follows: The CNC control system generates corresponding feed speed commands based on the imported three-dimensional model of the workpiece and the real-time calculated surface geometric parameters. These commands are sent to the feed motor, controlling it to rotate at a specific speed. The feed motor drives the ball screw to rotate synchronously, and the rotational motion of the ball screw is converted into linear motion through the nut pair, thereby driving the connected grinding head seat 20 or clamping seat to make precise linear reciprocating movements along the guide rail. During this process, the guide rail provides rigid guiding support, eliminating the influence of lateral forces on motion accuracy; while the high-efficiency transmission of the ball screw ensures the responsiveness of speed control. Because the feed motor supports stepless speed regulation, the entire feed drive assembly 4 can achieve continuous and smooth changes in feed speed, thereby adapting to the dynamic adjustment requirements of feed amount when machining surfaces with different radii of curvature, and avoiding surface quality defects caused by sudden speed changes.

[0071] As a preferred embodiment, the solution of this application is implemented as follows: When grinding a blade surface with variable curvature, the CNC control system identifies that the curvature of the current machining area is large, requiring a reduction in feed speed to ensure grinding fit. It then sends a low-frequency pulse signal to the feed motor. The feed motor reduces its speed, driving the ball screw to rotate slowly, causing the grinding head holder 20, equipped with the grinding head body 21, to advance smoothly along the guide rail at a low speed. When machining a flat area with less curvature, the CNC control system automatically increases the output frequency, the feed motor accelerates its rotation, and the ball screw drives the grinding head holder 20 to move rapidly, thereby improving machining efficiency. Throughout the entire movement, the grinding head holder 20 slides closely against the guide rail without any shaking, ensuring the accuracy of the grinding trajectory.

[0072] Through the above technical solution, this application achieves the synergy of stepless adjustment of feed speed and high-precision linear motion. By employing a feed motor coupled with a ball screw transmission, the feed speed can be flexibly and continuously varied according to the complexity of the surface, solving the problem that traditional stepped speed regulation is difficult to match the machining rhythm of complex surfaces. Simultaneously, thanks to the guiding effect of the guide rail and the low backlash characteristic of the ball screw, crawling and vibration phenomena during the feed process are effectively eliminated, thereby ensuring the surface finish and dimensional accuracy of the ground surface and improving overall machining efficiency.

[0073] Example 6: In one optional embodiment, the transmission ratio between the worm 222 and the worm wheel 223 in the angle adjustment mechanism 22 is 1:30-1:50, and the replaceable soft claw 321 is made of brass, with the difference between the curvature of its contact surface and the curvature of the workpiece surface being ≤0.01mm.

[0074] In the angle adjustment mechanism 22, the transmission ratio between the worm 222 and the worm wheel 223 can be the ratio of the number of rotations of the worm 222 to the number of rotations of the worm wheel 223, and its value can be any value between 1:30 and 1:50. This transmission ratio is set to achieve fine-tuning control of the angle of the grinding head body 21 through a high reduction ratio. When the CNC control system drives the first servo motor 221 to rotate, the worm 222 drives the worm wheel 223 to rotate at a lower speed, thereby converting the rapid rotation of the motor into precise angle changes of the grinding head body 21. This technical feature has a direct transmission relationship with the grinding head body 21 and the first servo motor 221. Through the self-locking characteristic generated by the large transmission ratio, it can effectively resist the reverse torque generated during grinding after the grinding head is adjusted to the target angle, preventing unexpected displacement or vibration of the grinding head, ensuring that the angle between the grinding head axis and the normal vector of the complex curved surface remains stable, thereby achieving high-precision attitude positioning.

[0075] The replaceable soft jaw 321 can be made of a metal material with good ductility, wear resistance, and a moderate coefficient of friction; in this embodiment, brass is preferred. Compared to hard materials such as steel, brass has lower hardness, which can prevent pressure marks or scratches on the workpiece surface during clamping. Its good machinability also facilitates customized finishing according to the workpiece curvature. The replaceable soft jaw 321 is mounted on the hydraulic chuck 320 and serves as the part of the clamping mechanism 32 that directly contacts the workpiece. Its degree of matching with the workpiece's curved surface directly determines the uniformity of the clamping force distribution. This technical feature forms a tight clamping fit with the clamping seat, the hydraulic chuck 320, and the workpiece to be processed. Through the adaptation of material hardness and surface geometry, the effective contact area is increased, transforming point or line contact into surface contact, thereby ensuring clamping stability while protecting the integrity of the workpiece surface.

[0076] The difference between the curvature of the contact surface of the replaceable soft jaw 321 and the curvature of the workpiece surface can refer to the fitting error of their geometry within the contact area, and this difference can be limited to ≤0.01mm. This precision requirement means that the concave or convex contour of the soft jaw 321 needs to be precision machined or on-site adjusted to reproduce the geometric features of the workpiece surface with extremely high accuracy. This technical feature has an indirect data linkage with the online probe system and CNC control system, that is, the system can guide the adjustment of the soft jaw 321 or directly select a soft jaw 321 with a preset curvature based on the imported 3D model of the workpiece or online measurement results. By controlling this curvature difference within the micron range, local stress concentration caused by poor contact can be eliminated, preventing the workpiece from slipping or deforming under high-speed rotation or large cutting forces, and ensuring positional stability during the grinding process.

[0077] Specifically, the working process and principle of this application are as follows: When complex curved surface grinding is required, the replaceable soft jaw 321 is first selected or modified according to the geometric characteristics of the workpiece, so that the difference between the curvature of its contact surface and the curvature of the workpiece surface is controlled within ≤0.01mm, and the characteristics of brass material are used to achieve flexible and stable clamping of the workpiece. Subsequently, the CNC control system drives the first servo motor 221 to drive the worm gear 222 to rotate according to the calculated grinding head angle adjustment amount. Since the transmission ratio between the worm gear 222 and the worm wheel 223 is set between 1:30 and 1:50, the rotation of the motor is greatly reduced and converted into a small angle deflection of the worm wheel 223 and the grinding head body 21. Utilizing the self-locking characteristics of the worm wheel 223 and worm gear 222 mechanism, the grinding head is mechanically locked after reaching the specified angle, resisting external interference without continuously consuming electrical energy. In this state, the grinding head body 21 maintains an ideal relative posture with the workpiece surface to perform grinding operations. The high transmission ratio ensures the resolution of angle adjustment, while the high-precision soft jaw 321 ensures the reliability of clamping. The synergistic effect of the two ensures the accurate execution of the grinding trajectory.

[0078] As a preferred embodiment, the specific implementation of this application is as follows: For the complex curved surface grinding of the root of an aero-engine blade, the workpiece material is a high-temperature alloy, and the surface must be free of damage. The operator first imports the three-dimensional model of the blade through the CNC control system, and the system calculates the optimal radius of curvature for the clamping area. Then, a set of replaceable soft jaws 321 made of brass is selected, and the inner surface of the soft jaws 321 is precision-machined using a CNC lathe based on the calculated curvature data. A coordinate measuring machine is used to inspect the surface, ensuring that the difference between the curvature of the soft jaw 321 contact surface and the curvature of the blade root surface is strictly controlled within 0.008 mm. The prepared soft jaws 321 are installed into the hydraulic chuck 320, the blade is placed in, and hydraulic clamping is applied, at which point the blade and soft jaws 321 achieve full contact. During the grinding head angle adjustment stage, the system commands the first servo motor 221 to rotate, driving the worm gear 223 and worm 222 with a transmission ratio of 1:45 to adjust the grinding head to an orientation consistent with the normal direction of the blade surface with extremely high resolution. Thanks to the large transmission ratio of 1:45, the grinding head did not retract or wobble even when subjected to grinding forces after positioning. Throughout the grinding process, the brass soft jaws 321 effectively dispersed the clamping force, preventing deformation of the thin-walled structure of the blade, while the high-precision angular positioning ensured the uniform removal of grinding allowance, ultimately achieving high-precision, damage-free machining of the blade root surface.

[0079] Through the above technical solution, this application achieves a significant improvement in the resolution and static stiffness of the angle adjustment mechanism 22 due to the adoption of a high transmission ratio worm gear 223 and worm 222 mechanism of 1:30 to 1:50. This effectively eliminates the angle error caused by transmission backlash and ensures the miniaturization and stability of the grinding head posture control. At the same time, due to the adoption of replaceable soft jaws 321 made of brass and the control of the contact surface curvature difference within 0.01mm, a high degree of conformal contact between the soft jaws 321 and the curved surface of the irregular workpiece is achieved. This avoids the point contact stress concentration and workpiece surface damage caused by traditional hard jaw clamping, greatly improving the reliability and processing consistency of the clamping process. This solves the problem of insufficient processing accuracy caused by unstable clamping or rough angle adjustment during the grinding of complex curved parts.

[0080] Example 7: In an optional embodiment, this application further defines a CNC grinding machine with an adjustable grinding head according to the above embodiments. One end of the worm 222 of the angle adjustment mechanism 22 meshes with the worm wheel 223, and the other end is directly fixedly connected to the swing shaft of the grinding head body 21. The worm wheel 223 and the worm 222 are both housed inside the adjustment seat 220, which is fixed on the grinding head seat 20. The swing axis of the grinding head body 21 around the horizontal axis is collinear with the central axis of the worm 222.

[0081] Among them, the angle adjustment mechanism 22, as the core execution unit for precise control of the grinding head posture, directly determines the sensitivity, stability, and positioning accuracy of the grinding head angle adjustment through the connection form, arrangement, and positioning accuracy of its transmission structure. In this embodiment, by optimizing and limiting the assembly relationship of the worm gear 222, worm wheel 223, swing shaft, and adjustment seat 220, a precision transmission structure with zero clearance, no eccentricity, and high protection is constructed. This eliminates transmission errors, lateral forces, and external interference from the mechanical construction level, enabling the grinding head to maintain stable angle positioning and smooth movement during complex curved surface grinding.

[0082] The worm gear 222, as the transmission component that directly drives the oscillation of the grinding head, meshes with the worm wheel 223 at one end, while the other end is directly and fixedly connected to the oscillation shaft of the grinding head body 21 without going through intermediate links such as couplings or adapters, forming an integrated transmission structure. The rigid connection between the worm gear 222 and the oscillation shaft eliminates the fit clearance, angle lag, and transmission deviation caused by intermediate transmission links, allowing the torque output by the first servo motor 221 to be directly and synchronously transmitted to the grinding head body 21, significantly improving the response speed and control accuracy of angle adjustment. The worm wheel 223 and worm gear 222, as the core transmission pair, are enclosed inside the adjusting seat 220. The adjusting seat 220 forms a protective shell, isolating the transmission components from the external cutting environment, effectively preventing grinding dust, cutting fluid, and metal chips from intruding into the meshing surface, avoiding wear, jamming, and corrosion of the transmission components, extending the service life of the worm wheel 223 and worm gear 222 mechanism, and maintaining long-term transmission accuracy.

[0083] The adjusting seat 220 is fixedly installed on the grinding head seat 20, forming a stable support base to ensure the overall rigidity of the angle adjusting mechanism 22 and prevent structural loosening or deformation caused by cutting force impact during processing. The swing axis of the grinding head body 21 around the horizontal axis is on the same straight line as the central axis of the worm gear 222, realizing a collinear transmission arrangement. This eliminates transmission eccentricity, lateral force component and radial sway, and avoids vibration, noise and angle deviation caused by axis offset. When the grinding head is adjusted within the range of 0-90°, the movement is smooth and without swaying, and the posture positioning is drift-free.

[0084] Specifically, the working process and principle of this application are as follows: The CNC control system issues angle adjustment commands based on the surface geometry parameters. The first servo motor 221 drives the worm gear 223 to rotate, and the worm gear 223 drives the worm 222 to rotate synchronously. The worm 222 directly drives the swing shaft of the grinding head body 21 to rotate, accurately converting the rotational motion into the angle swing of the grinding head. The power transmission is backlash-free and lossless. The adjustment seat 220 forms a closed protection for the worm gear 223 and worm 222, ensuring continuous and stable meshing of the transmission pair. The swing axis and the worm 222 axis are set collinearly, so that the grinding head always swings smoothly along the ideal axis without eccentricity, offset, or vibration. During the grinding process, the angle and posture of the grinding head are not affected by the transmission backlash and lateral force, and always maintain precise matching with the surface normal, thereby ensuring the contour accuracy and surface quality of the surface grinding.

[0085] As a preferred embodiment, in the grinding of complex curved surfaces such as aero-engine blades and precision molds, the grinding head needs to perform high-frequency, high-precision angle adjustments based on changes in surface curvature and normal. With the transmission structure of this embodiment, the worm gear 222 directly drives the oscillating shaft, significantly reducing angle following error; the enclosed arrangement of the worm wheel 223 and worm gear 222 reduces potential malfunctions; and the collinear arrangement ensures that the grinding head operates without vibration or offset during continuous oscillation. Even under prolonged, high-load cutting conditions, the grinding head's angle positioning remains stable, with no attenuation of transmission accuracy, effectively improving the machining consistency, dimensional accuracy, and surface finish of complex curved surfaces.

[0086] Through the above technical solutions, this application achieves high-precision, high-rigidity, and high-stability transmission in the grinding head angle adjustment mechanism 22. The structure of directly connecting the worm gear 222 to the swing shaft eliminates intermediate transmission backlash, improving angle adjustment accuracy and response speed. Enclosing the worm wheel 223 and worm gear 222 inside the adjustment seat 220 enhances the protective performance and service life of the transmission mechanism. The swing axis and the worm gear 222 axis are arranged collinearly, eliminating eccentricity and lateral forces, reducing grinding vibration, and further improving the grinding head's posture positioning accuracy. This significantly improves the grinding accuracy, processing stability, and equipment reliability of complex curved surface parts.

[0087] Example 8: Existing grinding methods, when machining complex curved surfaces, often rely on operator experience to set key parameters such as grinding head angle, feed rate, and clamping force. This manual control method is not only inefficient but also struggles to accurately match the normal vector changes and curvature characteristics of complex surfaces, leading to problems such as overcutting, undercutting, or workpiece deformation during grinding. Furthermore, the lack of a systematic automated verification and real-time feedback mechanism makes the compatible machining of irregularly shaped and conventional parts extremely difficult, failing to meet the demands of high-precision intelligent manufacturing.

[0088] This application also provides a method for adjusting the accuracy of a CNC grinding machine based on the adjustable grinding head of the above embodiments, the method comprising the following steps: Step S1: Import the 3D model of the workpiece and automatically extract the geometric parameters of the complex surface, including normal vector, curvature, and tangent inclination angle; This step involves the CNC control system receiving a digital 3D model file of the workpiece from an external source and analyzing the model data using a built-in surface machining parameter calculation module. The normal vector is a vector perpendicular to the tangent plane at a point on the surface, representing the spatial orientation of that point; curvature is a geometric quantity describing the degree of surface bending, with a larger value indicating a more curved surface; and the tangent angle is the angle between the tangent line of the surface and a reference horizontal plane. These geometric parameters are calculated using differential geometry algorithms by reading the mesh data or NURBS surface equations of the 3D model. This step provides fundamental data support for subsequent machining path planning, ensuring that all control commands originate from the actual geometric features of the workpiece. For example, when importing a hyperboloid model of an aircraft blade, the system automatically traverses thousands of sampling points on the blade surface, calculating the normal vector coordinates (nx, ny, nz) and the local curvature value k of each sampling point. This automatic extraction method eliminates errors caused by manual measurement, laying a data foundation for high-precision grinding. This step aims to transform the abstract design model into quantified geometric information that can be recognized and processed by the CNC system, thereby enabling the digital reconstruction of complex surface features.

[0089] Step S2: Calculate the processing path parameters; This step, based on the extracted geometric parameters, uses a pre-defined mathematical model and physical formulas to calculate the specific control quantities required to drive the actions of each actuator. Specifically, it includes the following sub-processes: S21, calculate the angle θ between the normal vector of the surface machining point and the direction vector of the grinding head axis. This angle θ reflects the degree of deviation between the grinding head axis and the normal of the workpiece surface. Its calculation formula involves vector dot product operation, where n is the normal vector of the surface machining point and m is the direction vector of the grinding head axis. By calculating this angle, the target angle that the angle adjustment mechanism 22 needs to rotate can be determined to ensure that the grinding head is perpendicular to the surface during grinding. For example, if the normal vector of a certain point is (0,0,1), and the current grinding head axis direction is (0,1,0), then the calculated angle θ is 90°, and the system needs to drive the first servo motor 221 to adjust the grinding head posture until θ approaches 0°.

[0090] Calculation process: Dot product: ; Length of the module: ; Substitute into the formula: ; S22, calculate the grinding head height adjustment amount h based on the radius of curvature R of the curved surface and the horizontal distance l from the contact point between the grinding head and the curved surface to the center of the curved surface. The height adjustment amount h can refer to the distance the grinding head body 21 needs to move in the vertical direction to compensate for the height difference caused by the undulations of the curved surface. Its calculation formula is as follows: This parameter directly determines the extension length of the electric telescopic rod, ensuring that the cutting edge of the grinding head always conforms to the curved surface profile.

[0091] S23. Calculate the angular velocity Ω of the rotary table 301 based on the workpiece rotation radius r and the target grinding linear velocity V. The angular velocity Ω is used to control the rotational speed of the third servo motor 300 to ensure a constant grinding linear velocity at different radii, avoiding uneven surface quality caused by linear velocity fluctuations. The calculation formula is as follows: .

[0092] S24, based on the surface curvature k and the target clamping force requirement, calculate the clamping force F of the clamping mechanism 32. The formula for calculating the clamping force F is as follows: ,in For the curvature of the surface, This is a preset positive constant used to ensure that the clamping force is non-zero when machining a flat surface (with zero curvature). The formula defines the preset clamping force coefficient, where S is the clamping contact area. This formula establishes a dynamic mapping relationship between curvature and clamping force. The greater the curvature (the steeper the surface), the more the required clamping force needs to be adjusted to prevent workpiece slippage or deformation.

[0093] S25, based on grinding force Calculate the locking force required by the electromagnetic locking mechanism based on the contact angle θ between the grinding head and the workpiece. The formula for calculating the locking force is as follows: This parameter is used to guide the CNC system in adjusting the current of the electromagnet to ensure that the grinding head holder 20 or the clamping seat will not undergo slight displacement when subjected to grinding force in a specific direction.

[0094] S26, based on the surface curvature k and the basic feed rate Adaptively adjust the feed speed of feed drive component 4 Feed rate The calculation formula is , where k is the numerical value of the surface curvature. This mechanism achieves adaptive control by slowing down when encountering curves and accelerating when encountering flat surfaces. In areas with large curvature, the feed rate is reduced to ensure machining accuracy, while in flat areas, the rate is increased to improve efficiency.

[0095] The calculation processes for the aforementioned parameters are closely coordinated, with parameters such as angle, height, speed, and force being coupled together to form a complete machining strategy. Through this precise calculation based on mathematical models, complex surface geometry features can be transformed into specific machine instructions, significantly improving the scientific rigor and controllability of the machining process.

[0096] S3: The collision risk and machining trajectory of the machining path parameters calculated above are verified by the virtual simulation module built into the CNC control system. After the verification is passed, step S4 is executed. This step can refer to simulating the entire machining process in a digital twin environment using the virtual simulation module integrated into the CNC system before the actual hardware actions are initiated. The virtual simulation module is based on all the path parameters calculated above (including angle θ, height h, angular velocity Ω, feed rate...). The system constructs a dynamic motion model and detects interference or collisions between the grinding head assembly, clamping assembly, and bed 1 or other components. This step aims to identify potential mechanical conflicts and trajectory errors in advance, preventing equipment damage or workpiece scrap during actual machining. For example, the system simulates whether the oscillation angle of the grinding head during its movement from point A to point B would cause physical contact between the grinding head holder 20 and the fixture base. If the simulation results indicate a collision risk, the system will automatically alarm and pause execution, prompting a replanning of the path; only after the verification is completely successful will the system proceed to the next step. This pre-verification mechanism effectively avoids physical accidents caused by extreme values ​​in parameter calculations or logical flaws, ensuring the safety of equipment operation.

[0097] S4: Measure the actual position and orientation of the workpiece through the online probe system, calculate the clamping error compensation amount Δ, and control the CNC system to perform coordinate system compensation so that the compensation amount meets Δ≤0.002mm; This step utilizes an online probe system equipped on the adjustable clamping assembly 3 to perform high-precision detection of the actual spatial position and orientation of the clamped workpiece. The clamping error compensation Δ refers to the deviation vector between the workpiece's theoretical coordinate system and the actual clamping coordinate system, including translational and rotational deviations. This compensation is calculated by comparing the actual contact data collected by the probe with the theoretical data in the 3D model using the least squares method. Based on the calculated Δ value, the CNC control system automatically corrects the origin and axial deflection of the internal world coordinate system, thereby eliminating systematic errors caused by inaccurate manual clamping. For example, if the probe detects that the workpiece has shifted 0.0015mm in the positive X-axis direction and rotated 0.005° around the Z-axis, the system will immediately update the coordinate transformation matrix, ensuring that all subsequent motion commands are executed based on the corrected coordinate system. This step ensures that the final machining accuracy is not limited by the initial clamping accuracy, controlling the overall clamping error within 0.002mm, achieving micron-level positioning accuracy.

[0098] S5: Based on all the parameters calculated above and the compensation results above, control the grinding head angle adjustment mechanism 22, height adjustment mechanism 23, workpiece rotation and pitch mechanism, and feed drive assembly 4 to work together to achieve high-precision grinding of complex curved surfaces. This step is the execution phase, where the CNC control system distributes the final parameter instructions, after simulation verification and error compensation, to each underlying execution unit. The grinding head angle adjustment mechanism 22 drives the first and second servo motors 224 to adjust the spatial attitude of the grinding head based on the target angle θ; the height adjustment mechanism 23 controls the extension and retraction of the electric telescopic rod according to the height adjustment amount h to maintain consistent grinding depth; the workpiece rotation and pitch mechanism drives the third and fourth servo motors 310 according to the calculated angular velocity Ω and pitch angle, causing the workpiece to perform multi-axis linkage; the feed drive assembly 4 adjusts according to the adaptive feed speed... The ball screw drives a smooth relative feed motion. Simultaneously, the electromagnetic locking mechanism dynamically adjusts the current based on the calculated locking force requirement, locking the sliding mating surfaces. These components are strictly synchronized on the time axis, forming a multi-degree-of-freedom cooperative motion chain. For example, when machining a helical surface, the grinding head continuously changes angle while the workpiece rotates and pitches synchronously, and the feed axis adjusts its speed in real time to match the curvature changes. This step, through high-precision multi-axis linkage, transforms theoretical calculations into an actual material removal process, thereby achieving high-quality grinding of complex curved surface parts.

[0099] S6: During the processing, the angle data of each adjustment mechanism is collected in real time by the angle sensor and compared with the preset parameters to realize closed-loop feedback adjustment and ensure the accuracy and stability of the processing process.

[0100] This step refers to the continuous acquisition of the current actual angle value by angle sensors installed on the angle adjustment mechanism 22, rotation adjustment mechanism 30, and pitch adjustment mechanism 31 during the grinding operation. The preset parameter refers to the theoretical angle target value calculated and compensated as described above. Closed-loop feedback adjustment compares the difference between the real-time acquired actual angle and the theoretical target value. When the difference exceeds a preset small threshold (such as jitter caused by load changes), the CNC control system immediately issues a correction command, fine-tuning the output of the corresponding servo motor to quickly return the actual angle to the target range. This step aims to counteract angle drift caused by cutting force fluctuations, mechanical backlash, or thermal deformation during machining, maintaining the dynamic stiffness of the system. For example, if the grinding head experiences a reaction force during grinding of hard points, causing the angle to deviate by 0.002°, the angle sensor will instantly detect this change, and the system will immediately drive the servo motor to compensate in the opposite direction, eliminating the deviation. Through this real-time closed-loop monitoring and correction, extremely high stability of attitude control throughout the entire machining cycle is ensured, preventing the accumulation of errors.

[0101] This application, through the synergistic effect of the aforementioned technical features, constructs a high-precision control system covering the entire process from data input to closed-loop execution. By importing a 3D model and automatically extracting geometric parameters, and combining this with rigorous mathematical formulas to calculate angle, height, speed, and force parameters, the processing strategy is digitized and made more scientific. Pre-processing verification using a virtual simulation module effectively avoids the risk of physical collisions. Real-time compensation from an online probe system eliminates system errors in the clamping process. Finally, through multi-axis coordinated motion and real-time closed-loop feedback from angle sensors, dynamic accuracy and stability during the grinding of complex curved surfaces are ensured. This progressive control logic not only solves the problem that traditional manual parameter settings cannot adapt to complex curved surfaces, but also improves process robustness through an adaptive adjustment mechanism, achieving efficient and high-precision compatible processing of irregularly shaped and conventional parts.

[0102] Example 9: In an optional embodiment, the method further includes further control over the precision of the grinding head angle adjustment.

[0103] In step S2.1, the grinding head angle adjustment mechanism 22 is controlled to operate so that the matching error between the grinding head angle, workpiece posture, and complex curved surface meets the requirements. ,in The theoretical perspective required for machining complex curved surfaces; This step involves, based on the previously calculated angle between the grinding head axis direction vector and the surface normal vector, sending high-precision drive commands to the first servo motor 221 and the second servo motor 224 through the CNC control system, driving the worm gear 223 and worm 222 pair and the rotating shaft for fine-tuning. This can refer to the theoretically optimal grinding angle calculated based on the surface geometric parameters extracted from the workpiece's 3D model and combined with the grinding process requirements. This angle ensures that the grinding head generatrix is ​​perpendicular to the tangent plane of the surface to be machined at the contact point or forms a preset optimal cutting angle. (Adaptation error) This can refer to the actual angular position reached by the grinding head. From the perspective of theoretical goals The absolute difference between them. This difference is obtained by comparing the actual feedback data collected in real time by a high-resolution angle sensor installed inside the angle adjustment mechanism 22 with the theoretical data stored in the system. Its function is to lock the spatial attitude of the grinding head within a very small tolerance zone to eliminate angle deviations caused by mechanical transmission clearances, thermal deformation, and load changes. Specifically, when the actual angle is detected... Deviation At this time, the CNC control system will automatically generate correction pulses to drive the servo motor for reverse compensation until the error converges. For example, when machining the twisted surface of an aero-engine blade, if the theoretical grinding angle of a certain machining point is... The angle is calculated to be 45.000°. The control system will drive the grinding head assembly to ensure the actual stopping angle. The initial positioning angle falls within the range of 44.999° to 45.001°. If the initial positioning angle is 45.003°, the system will immediately trigger a fine-tuning program, driving the first servo motor 221 to reverse by a small step until the angle sensor reading enters the allowable range. Through this closed-loop angle control at the level of one-thousandth of a degree, the consistency between the grinding head and the surface normal can be greatly enhanced, ensuring that the grinding force mainly acts perpendicularly on the workpiece surface, significantly reducing the lateral shear force caused by angle deviation, thereby effectively improving the surface finish and contour dimensional accuracy of complex curved surfaces.

[0104] This application introduces The stringent precision constraints are closely coordinated with the aforementioned steps of automatically extracting geometric parameters and calculating theoretical angles based on 3D models. On this basis, high-precision angle execution relies on the accurate calculation of normal and direction vectors, while real-time angle feedback provides a reliable attitude reference for subsequent machining trajectory verification and adaptive feed rate adjustment. Furthermore, this precision control strategy effectively solves the problem of insufficient grinding fit caused by accumulated errors in traditional open-loop control, enabling the grinding machine to adapt to machining scenarios with extremely high requirements for surface contours, such as aero-engine blades and optical molds, ultimately achieving high-precision matching across the entire chain from theoretical calculation to physical execution.

[0105] Example 10: In an optional embodiment, the method further includes real-time closed-loop feedback adjustment of the grinding head posture during processing.

[0106] The angle data collected in real time by the angle sensor is compared with the theoretical angle θ calculated in step S2.1. The angle data can refer to the angle at which the first servo motor 221 drives the worm gear 223 to rotate the grinding head body 21 around the horizontal axis, and the angle at which the second servo motor 224 drives the grinding head body 21 to rotate around its own axis. This angle data is continuously collected and transmitted to the CNC control system during the grinding process by a high-precision angle sensor mounted on the angle adjustment mechanism 22. The theoretical angle θ is the ideal fitting angle calculated based on the imported three-dimensional workpiece model, after extracting the surface geometric parameters through the surface machining parameter calculation module, and according to the normal vector of the surface machining point and the direction vector of the grinding head axis. The calculation formula is as follows: ,in Let be the normal vector of the surface machining point. This refers to the direction vector of the grinding head axis. The difference comparison can be performed by the processing unit within the CNC control system, which subtracts the real-time acquired actual angle value from the preset theoretical angle θ to obtain the attitude deviation. For example, when the theoretical angle θ is set to 45.000°, if the actual angle collected by the angle sensor is 44.995°, the system calculates a difference of 0.005°. This step aims to monitor the attitude changes of the grinding head in real time during the machining of complex curved surfaces, identify minute deviations caused by cutting force fluctuations, mechanical vibrations, or thermal deformation, and provide an accurate data basis for subsequent correction actions.

[0107] When the difference exceeds the preset threshold, the CNC control system automatically adjusts the first servo motor 221 and / or the second servo motor 224 to correct the grinding head posture. The preset threshold is the maximum allowable angular deviation value set according to the workpiece surface roughness requirements and the contact characteristics between the grinding head and the workpiece. It is typically set between 0.001° and 0.01° to ensure grinding accuracy. The first servo motor 221 is an actuator that drives the worm gear 223, thereby causing the grinding head body 21 to rotate around the horizontal axis within a range of 0-90°. The second servo motor 224 is an actuator connected to the rotating shaft of the grinding head body 21, used to drive it to rotate around its own axis from 0-360°. Automatic adjustment can be achieved by the CNC control system determining the attitude deviation amount. When the actual angle exceeds a preset threshold, a compensation control command is immediately generated. By changing the frequency or phase of the pulse signal input to the first servo motor 221 or the second servo motor 224, the motor is driven to rotate in the opposite or same direction with fine adjustments until the actual angle returns to the allowable error range of the theoretical angle θ. For example, if the actual angle of the grinding head around the horizontal axis is detected to be less than the theoretical angle and the difference exceeds the threshold, the CNC system will control the first servo motor 221 to rotate slightly in the forward direction. Utilizing the self-locking characteristics and high transmission ratio (1:30-1:50) of the worm gear 222 and worm wheel 223 mechanism, the rotational motion of the motor is converted into a high-precision angular displacement of the grinding head seat 20, thereby offsetting the attitude deviation. This step, by dynamically adjusting the output of the actuator, effectively suppresses the cumulative error caused by external disturbances, ensuring that the grinding head and the complex curved surface maintain the best fit throughout the entire machining path, significantly improving the stability and product qualification rate of long-term continuous grinding tasks.

[0108] This application constructs a complete closed-loop feedback adjustment mechanism through real-time acquisition of angle data, accurate comparison of theoretical values, and dynamic correction of the execution motor in the above steps. Specifically, the angle sensor, as the sensing end, continuously captures the instantaneous posture of the grinding head in a high-speed grinding environment; the CNC control system, as the decision-making end, uses the theoretical angle θ pre-calculated in step S2.1 as a benchmark to quickly determine whether the current state deviates from the optimal machining trajectory; the first servo motor 221 and the second servo motor 224, as the execution end, respond to the system's correction commands and use their high-precision positioning capabilities to correct the pitch and rotation angles of the grinding head at the micrometer or even sub-arcsecond level. This synergistic effect of sensing, decision-making, and execution enables the grinding machine to actively adapt to posture disturbances caused by changes in cutting force, machine tool thermal expansion, or external vibrations during processing, rather than passively bearing errors. Through this dynamic compensation, not only are dynamic error sources that static settings cannot handle eliminated, but also the phenomenon of local over-grinding or under-grinding caused by posture mismatch is significantly reduced. Thus, while ensuring the geometric accuracy of complex curved surfaces, the service life of the grinding head is effectively extended and the overall quality consistency of the workpiece surface is improved.

[0109] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A CNC grinding machine with an adjustable grinding head, comprising a bed (1), characterized in that, The bed (1) is equipped with a numerical control system, an adjustable grinding head assembly (2), an adjustable clamping assembly (3), and a feed drive assembly (4). The CNC control system is electrically connected to the adjustable grinding head assembly (2), the adjustable clamping assembly (3), and the feed drive assembly (4) to control the action of each assembly. The adjustable grinding head assembly (2) and the adjustable clamping assembly (3) are slidably mounted on the bed (1), and the feed drive assembly (4) drives the two to feed relative to each other. The adjustable grinding head assembly (2) includes a grinding head seat (20) and a grinding head body (21) mounted on the grinding head seat (20). An angle adjustment mechanism (22) and a height adjustment mechanism (23) are provided between the grinding head seat (20) and the grinding head body (21). The angle adjustment mechanism (22) includes an adjustment seat (220), a first servo motor (221), a worm (222), a worm wheel (223), and a second servo motor (224). The worm wheel (223) and the first servo motor (221) are disposed in the adjustment seat (220). One end of the worm (222) meshes with the worm wheel (223), and the other end is connected to the grinding head body (21). The first servo motor (221) drives the worm wheel (223), thereby causing the grinding head body (21) to rotate around the horizontal axis from 0 to 90°. The second servo motor (224) is connected to the rotation axis of the grinding head body (21), thereby driving the rotation axis to rotate and causing the grinding head body (21) to rotate around its own axis from 0 to 360°. The height adjustment mechanism (23) includes an electric telescopic rod, which drives the grinding head body (21) to move up and down. The adjustable clamping assembly (3) includes a clamping base and a rotation adjustment mechanism (30), a pitch adjustment mechanism (31), and a clamping mechanism (32) disposed on the clamping base. The rotation adjustment mechanism (30) includes a third servo motor (300) and a rotary table (301). The third servo motor (300) can drive the rotary table (301) to rotate continuously from 0 to 360° around the vertical axis. The pitch adjustment mechanism (31) includes a fourth servo motor (310). The pitch axis (311) and pitch support (312) are provided. The fourth servo motor (310) drives the pitch support (312) to pitch and rotate around the pitch axis (311) in the range of 0-90°. The clamping mechanism (32) includes a hydraulic chuck (320), a replaceable soft claw (321) and a suction cup (322). The replaceable soft claw (321) is mounted on the hydraulic chuck (320), and the vacuum suction cup (322) is mounted at the center of the pitch support (312). Angle sensors are provided on the angle adjustment mechanism (22), rotation adjustment mechanism (30), and pitch adjustment mechanism (31), and the angle sensors are electrically connected to the CNC control system. The CNC control system includes a surface machining parameter calculation module. The module automatically extracts the surface geometric parameters based on the imported three-dimensional model of the workpiece and calculates the angle adjustment amount and height adjustment amount of the adjustable grinding head assembly, the clamping force of the adjustable clamping assembly, and the feed speed of the feed drive assembly and the locking force of the locking mechanism, respectively.

2. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The adjustable grinding head assembly (2) and the adjustable clamping assembly (3) are respectively provided with electromagnetic locking mechanisms, the electromagnetic locking mechanisms including electromagnets, armatures, locking blocks and return springs; The electromagnet is fixedly installed on the grinding head seat (20) or the clamping seat, the armature is fixedly connected to the locking block, and the return spring is sleeved between the locking block and the electromagnet; When the electromagnet is energized, it attracts the armature and drives the locking block to press against the sliding mating surface between the bed and the corresponding sliding component, thus achieving locking. When the power is off, the reset spring pushes the locking block to reset and release. The CNC control system dynamically adjusts the energizing current of the electromagnet according to the real-time grinding force to change the magnitude of the locking force.

3. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The numerical control system adopts a PLC programmable controller, which integrates a virtual simulation module and a process parameter library. It supports direct import of three-dimensional models and has a built-in angle encoder. The virtual simulation module is used to check the collision risk and trajectory of the imported machining path before machining.

4. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The adjustable clamping assembly (3) is equipped with an online probe system, which is used to automatically measure the actual position and orientation of the workpiece. The CNC control system performs coordinate system compensation based on the measurement results to eliminate clamping errors. The compensation amount is ≤0.002mm.

5. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The feed drive assembly (4) includes a feed motor, a ball screw and a guide rail. The feed motor drives the ball screw to rotate, which in turn drives the grinding head seat (20) and the clamping seat to move smoothly along the guide rail. The feed speed can be steplessly adjusted.

6. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The transmission ratio of the worm (222) and worm wheel (223) in the angle adjustment mechanism (22) is 1:30-1:

50. The replaceable soft claw (321) is made of brass, and the difference between the curvature of its contact surface and the curvature of the workpiece surface to be processed is ≤0.001mm.

7. The CNC grinding machine with an adjustable grinding head according to claim 1, characterized in that: The worm (222) of the angle adjustment mechanism (22) is engaged with the worm wheel (223) at one end, and directly fixedly connected to the swing shaft of the grinding head body (21) at the other end; the worm wheel (223) and the worm (222) are both installed inside the adjustment seat (220), the adjustment seat (220) is fixedly installed on the grinding head seat (20), and the swing axis of the grinding head body (21) around the horizontal axis is collinear with the central axis of the worm (222).

8. A method for adjusting the precision of a CNC grinding machine based on an adjustable grinding head according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Import the 3D model of the workpiece and automatically extract the geometric parameters of complex surfaces, including normal vector, curvature, and tangent inclination angle; S2. Calculate the processing path parameters: S2.1 Calculate the angle θ between the normal vector of the surface machining point and the direction vector of the grinding head axis, using the formula: where n is the normal vector of the surface machining point and m is the direction vector of the grinding head axis; S2.

2. Based on the radius of curvature R of the surface and the horizontal distance l from the contact point between the grinding head and the surface to the center of the surface, calculate the grinding head height adjustment amount h. The formula is: h=R-√(R²-l²); S2.

3. Calculate the angular velocity Ω of the rotary table (301) based on the workpiece rotation radius r and the target grinding linear velocity v. The formula is: v = Ω·r; S2.

4. Based on the surface curvature k and the target clamping force requirement, calculate the clamping force F of the clamping mechanism (32). The formula is: F = (k + k_min)·k0·S, where k = 1 / R is the surface curvature, k_min is a preset positive constant used to ensure that the clamping force is non-zero during plane machining, k0 is a preset clamping force coefficient, and S is the clamping contact area. S2.

5. Calculate the locking force required by the electromagnetic locking mechanism based on the contact angle θ between the grinding force F_m and the grinding head and the workpiece. The formula is: F_lock ≥ F_m·sinθ; S2.

6. Based on the surface curvature k and the basic feed speed v0, the feed speed v_f of the feed drive component (4) is adaptively adjusted. The formula is: v_f=v0 / (1+k), where k is the value of the surface curvature in mm. -1 ; S3. The collision risk and machining trajectory of the machining path parameters calculated in step S2 are verified by the virtual simulation module built into the CNC control system. If the verification fails, return to step S2 to readjust and calculate the machining path parameters. After the verification passes, proceed to step S4. S4. Measure the actual position and orientation of the workpiece through the online probe system, calculate the clamping error compensation amount Δ, and control the CNC system to perform coordinate system compensation so that the compensation amount meets Δ≤0.002mm; S5. Based on all the parameters calculated in step S2 and the compensation results in step S4, control the grinding head angle adjustment mechanism (22), height adjustment mechanism (23), workpiece rotation and pitch mechanism, and feed drive assembly (4) to coordinate their actions to achieve high-precision grinding of complex curved surfaces. S6. During the processing, the angle data of each adjustment mechanism is collected in real time by the angle sensor and compared with the preset parameters to realize closed-loop feedback adjustment and ensure the accuracy and stability of the processing process.

9. The method for adjusting the accuracy of a CNC grinding machine according to claim 8, characterized in that: In step S21, the action of the grinding head angle adjustment mechanism (22) is controlled so that the matching error between the grinding head angle, the workpiece posture and the complex curved surface is satisfied |θ-θ0|≤0.001°, where θ is the actual angle between the grinding head axis and the normal of the workpiece surface, and θ0 is the theoretical angle required for the processing of the complex curved surface.

10. The method for adjusting the accuracy of a CNC grinding machine according to claim 8, characterized in that: The closed-loop feedback adjustment in step S6 includes: comparing the angle data collected in real time by the angle sensor with the theoretical angle θ calculated in step S21. When the difference exceeds a preset threshold, the CNC control system automatically adjusts the first servo motor (221) and / or the second servo motor (224) to correct the grinding head posture.

Images