Laser-assisted milling machining head and method

Abstract

This invention relates to a laser-assisted milling head and method. It connects to a machine tool via a machine tool connector and is used for machining workpieces. The machining head includes: a spindle connected to the machine tool connector; a milling cutter connected to the spindle drive end and used for milling the workpiece; and a plurality of laser galvanometer assemblies connected to the spindle and uniformly arranged circumferentially around the spindle's central axis. Each laser galvanometer assembly includes one laser galvanometer, and each group of laser galvanometer assemblies is independently controlled. Compared with existing technologies, this invention can achieve uniform, continuous, and dead-angle-free laser preheating of the workpiece circumferentially, thereby improving the process stability and machining quality of laser-assisted milling.

Description

Technical Field

[0001] This invention relates to the field of laser-assisted milling technology, and in particular to a laser-assisted milling head and method. Background Technology

[0002] Hard and brittle materials such as cemented carbide, engineering ceramics, and composite materials are widely used in high-end manufacturing fields such as aerospace, energy equipment, precision instruments, and defense technology due to their high hardness, high wear resistance, good chemical stability, and excellent high-temperature performance. Components made from these materials often have complex geometries, requiring precision milling to achieve the manufacturing requirements of high accuracy and high surface integrity. However, the inherent high hardness and low fracture toughness of hard and brittle materials lead to problems such as high cutting forces, severe tool wear, low machining efficiency, and susceptibility to machining cracks and chipping during conventional milling, which seriously restrict their machining quality and application reliability.

[0003] Laser-assisted milling technology introduces a high-energy laser beam during the milling process to locally and transiently heat the workpiece's cutting area, causing thermal softening of the material and significantly reducing its hardness and cutting resistance, thereby improving its machinability. This technology can effectively extend tool life, improve cutting efficiency, enhance surface quality, and suppress machining damage, providing an important approach for achieving efficient and precise milling of hard and brittle materials. However, successfully integrating this technology into dynamic milling processes, especially when applied to complex curved surfaces or circumferential milling, faces a key challenge: the laser beam is easily obstructed by the machining tool, workpiece, or fixture during its spatial propagation, resulting in ineffective preheating of the machining area and the formation of machining dead zones.

[0004] To address the problem of laser occlusion, existing technologies have proposed solutions using multiple laser galvanometers. For example, patent publication number CN117564797A discloses a laser galvanometer device for laser-assisted milling of complex curved surfaces. This device employs multiple laser galvanometers optically connected in series via a light guide arm, and uses a deflectable mirror to selectively activate a single galvanometer. This solution effectively avoids optical path occlusion problems under specific poses by switching between activating galvanometers at different positions.

[0005] However, this device operates in a "time-sharing, single-operation" mode, where only one laser galvanometer is activated and outputs laser light at any given time. In high-speed continuous milling, especially in machining scenarios where the tool performs circumferential feed, this mode makes it difficult to achieve synchronous or rapid following heating of the workpiece's circumferential area by the laser beam. Laser heat input may experience delays or missed areas in time and space, leading to uneven and discontinuous material preheating. This uneven heating directly affects the uniformity of material softening, potentially causing problems such as fluctuating cutting forces, inconsistent surface quality, and uneven tool wear, ultimately limiting the overall effectiveness and stability of the laser-assisted milling process.

[0006] Therefore, existing galvanometer-based solutions, while addressing the obstruction problem, introduce a new issue: insufficient continuity of circumferential heating. Currently, there is still a lack of a laser-assisted milling solution that can fundamentally achieve uniform, continuous, and blind-angle-free laser preheating of the workpiece's circumference. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art, which are discontinuous and uneven laser heating due to the time-sharing working mode during high-speed continuous and circumferential milling. This invention provides a laser-assisted milling head and method to achieve uniform, continuous, and dead-angle-free laser preheating of the workpiece circumferentially, thereby improving the process stability and processing quality of laser-assisted milling.

[0008] The objective of this invention can be achieved through the following technical solutions: In one aspect, the present invention provides a laser-assisted milling head, which is connected to a machine tool via a machine tool connector and is used for machining workpieces. The machining head includes: The spindle connected to the machine tool connector; A milling cutter connected to the spindle drive end and used for milling the workpiece; And a plurality of laser galvanometer assemblies connected to the main shaft and uniformly arranged around the central axis of the main shaft, wherein each laser galvanometer assembly includes a laser galvanometer, and each group of laser galvanometer assemblies is independently controlled.

[0009] Furthermore, the laser galvanometer assembly is provided in 2 to 5 groups.

[0010] Furthermore, the laser galvanometer is rotatably connected to the main shaft via a ball gear transmission component; the ball gear transmission component is driven to rotate by a driving component. The ball gear connecting transmission component includes a fixedly connected base and a ball part, wherein the base is fixedly connected to the laser galvanometer.

[0011] Furthermore, the driving component includes a motor and a driving gear. The driving gear is connected to the transmission shaft of the motor and meshes with the ball portion of the ball gear connecting transmission component. The motor drives the driving gear to rotate, thereby causing the ball gear connecting transmission component to rotate.

[0012] Furthermore, the spherical portion is a spherical gear with external teeth formed on its surface. The external teeth on the surface of the spherical portion are continuously distributed along its equatorial region or a specific latitude region, forming a spherical gear structure. The driving gear is a cylindrical gear or a bevel gear, and its tooth profile is adapted to the external teeth of the spherical portion to achieve meshing transmission.

[0013] Furthermore, the spindle is provided with several evenly distributed inclined surfaces in its circumference, and the inclined surfaces are provided with mounting grooves for the ball portion to be inserted. An upper ball cover and a lower ball cover are provided at the opening of the mounting groove. The upper ball cover and the lower ball cover are fixedly connected to the main shaft and constrain the spherical part within the mounting groove, so that the ball gear connecting transmission component and the main shaft form a spherical pair constraint.

[0014] Furthermore, taking the vertical line of the inclined surface as a reference, the rotation angle of the ball gear connecting transmission component is -15° to 15°. The inclination angle of the inclined surface is 0° to 45° with the vertical surface as a reference. When it is 0°, it means that the inclined surface is vertical. Preferably, it is 30° to 45°.

[0015] Furthermore, the processing head also includes a thermal camera assembly mounted on the spindle for acquiring thermal images of the area to be processed of the workpiece; And / or, the machining head further includes a force gauge disposed at the top of the milling cutter and used to acquire the cutting force signal of the milling cutter.

[0016] Furthermore, the thermal camera assembly is provided in several groups, the number of which corresponds to the number of the laser galvanometer assembly, with each group of thermal camera assemblies corresponding to one group of laser galvanometer assemblies.

[0017] Furthermore, the thermal camera assembly is disposed on the lower surface of the main shaft and located between adjacent laser galvanometer assemblies, which are evenly spaced around the central axis of the main shaft.

[0018] Furthermore, the force measuring instrument is provided with one.

[0019] Furthermore, the thermal camera assembly and / or force gauge are connected to a controller, which is electrically connected to the milling cutter and the laser galvanometer assembly.

[0020] Furthermore, the control process of the controller is as follows: Acquire thermal images of the area to be processed from the thermal camera assembly and / or cutting force signals from the force measuring instrument; The controller determines the current machining state based on the thermal image and / or the cutting force signal.

[0021] Furthermore, the machining head is equipped with both a thermal camera assembly and a force measuring instrument. The thermal camera assembly transmits the thermal image cutting force signal to the controller, and the force measuring instrument transmits the cutting force signal to the controller. When the highest temperature in the thermal image exceeds the material burn temperature threshold and the cutting force is less than 30% of the material's normal cutting force, it is judged as "excessive heat input, risk of overheating, or insufficient cutting force". When the highest temperature in the thermal image is less than 50% of the material burn temperature threshold and the cutting force is similar to the normal cutting force of the material (±5%), it is judged as "insufficient heat input and excessive cutting force".

[0022] Furthermore, the machine tool has a feed mechanism that drives the machine tool connector to move laterally and vertically.

[0023] In another aspect, the present invention also provides a laser-assisted milling method, which uses the aforementioned laser-assisted milling head for processing, and includes the following steps: Based on the location of the area to be processed, the operation of each laser galvanometer assembly is independently controlled to open individually, partially simultaneously, or all simultaneously, so that the opened laser galvanometer assembly emits laser beams to the corresponding circumferentially distributed area on the workpiece for preheating. The spindle drives the milling cutter to mill the area after synchronous preheating.

[0024] Furthermore, when the area to be processed is a small local area or located at a specific circumferential angle, a laser galvanometer assembly corresponding to that area is turned on separately to achieve precise and focused local preheating; When the area to be processed is a continuous, large range spanning multiple angles, multiple adjacent laser galvanometer assemblies covering the range are opened simultaneously to achieve continuous and uniform preheating of the area and to match the feed path of the milling cutter. When it is necessary to preheat the workpiece uniformly in the whole or a large area around the circumference, all laser galvanometer components are turned on at the same time to achieve rapid and comprehensive circumferential heating without dead angles, providing a uniform thermal environment for subsequent all-round milling.

[0025] Furthermore, during the milling process, the opening state and laser parameters of the laser galvanometer assembly are dynamically adjusted according to the real-time machining path to ensure that the material to be cut in front of the milling cutter is always in the best preheated state, while avoiding overheating of the machined or unmachined areas.

[0026] Compared with the prior art, the present invention has the following advantages: (1) This invention fundamentally solves the problem of continuous circumferential heating and achieves uniform preheating without dead angles. By uniformly arranging multiple laser galvanometer components around the central axis of the spindle and enabling each component to work independently, this invention ensures that the laser beam can cover the circumference of the workpiece from multiple angles from a physical structure perspective. This completely changes the "time-sharing, single-operation" mode in the prior art. When the tool is performing circumferential feed milling, multiple galvanometers can be controlled to work synchronously or in rapid relay, so that the laser heat input can act continuously and synchronously on the area to be processed in front of the tool, avoiding the problem of uneven material softening caused by laser heating delay or omission, and providing a uniform thermal environment for stable cutting.

[0027] (2) This invention possesses extremely high control flexibility and processing adaptability. Each laser galvanometer assembly can be independently controlled, supporting multiple working modes such as "individual, partial, and complete". It can intelligently select the most suitable laser beam combination mode according to the specific shape, size, and milling path of the area to be processed. Whether it is local finishing, continuous contour processing, or large-area surface processing, it can provide corresponding precise, efficient, or comprehensive preheating solutions, significantly improving the process's adaptability to different processing tasks and optimizing energy utilization efficiency.

[0028] (3) In this invention, each laser galvanometer is fixed to a ball-gear connecting transmission component. The spherical part of this transmission component is constrained within the mounting groove of the main shaft, enabling it to rotate up and down. By adjusting the drive component, the initial direction of the laser galvanometer can be macroscopically deflected, thereby shifting its scanning field of view. This allows the laser beam to dynamically adapt to the processing requirements of different curved surfaces, such as adjusting to the optimal incident angle when processing steep sidewalls, greatly enhancing the system's adaptability and process flexibility to different processing scenarios, and improving processing quality and efficiency.

[0029] (4) This invention constructs a real-time monitoring and feedback control loop for the thermal input and mechanical response during the machining process by integrating a thermal camera group on the spindle and a force gauge mounted on the tool holder, thereby accurately solving the core technological problem of force-thermal coupling balance. The thermal camera continuously acquires the temperature field distribution of the area to be machined, directly quantifying the thermal softening effect of the laser; the force gauge synchronously collects transient cutting forces, directly reflecting the material's cutting resistance and tool load. The control system receives these two signals and compares and makes decisions with the preset process safety range based on the material characteristics of the tool and workpiece. When the system determines that "the thermal input is insufficient and the cutting force is too large", it automatically increases the laser power to enhance softening; when it determines that "the thermal input is too high, there is a risk of overheating, or the cutting force is too small", it automatically reduces the laser power or increases the feed rate. Through this dynamic closed-loop adjustment, the machining area can be stably kept in a balanced state where the material is sufficiently softened and the cutting force is optimal, thereby improving machining efficiency and extending tool life while ensuring the integrity of the machined surface.

[0030] (5) The processing head of the present invention adopts a highly integrated modular design, with a compact structure, which is easy to integrate directly into traditional machine tools, thus reducing the threshold for the transformation and implementation of laser-assisted processing technology. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the milling head shown in Example 1; Figure 2 This is a side view of the milling head shown in Example 1; Figure 3 A partial view of the connection between the laser galvanometer and the spindle shown in Example 1. Figure 2 (Enlarged diagram of part A in the middle) Figure 4 This is an exploded view of the laser galvanometer and ball gear connecting transmission component shown in Example 1; Figure 5 This is a schematic diagram showing the connection between the driving component and the ball gear transmission component as shown in Example 1. Figure 3 (Cross-sectional view along axis BB). Figure 6 The diagram shows the scanning range of the milling head shown in Example 1. View a1, view a2, and laser schematic a3 of the laser-assisted milling head with a rotation angle of -15° for the ball gear connecting transmission component; view b1, view b2, and laser schematic b3 of the laser-assisted milling head with a rotation angle of 0° for the ball gear connecting transmission component; and view c1, view c2, and laser schematic c3 of the laser-assisted milling head with a rotation angle of 15° for the ball gear connecting transmission component. Figure 7The milling head shown in Example 1 is illustrated in the following machining diagrams: a) local finishing, b) continuous contour milling, and c) large-area end face milling. Figure 8 This is a schematic diagram of the circumferential finishing of the milling head shown in Example 1, where a is the milling of the scanning area handled by the first galvanometer, b is the milling of the scanning area handled by the second galvanometer, and c is the milling of the scanning area handled by the third galvanometer. Figure 9 This is a schematic diagram of the milling head shown in Example 2; Figure 10 This is a schematic diagram of the thermal camera assembly shown in Example 2.

[0032] Explanation of markings in the diagram: 1-Machine tool, 11-Frame, 12-Horizontal movement assembly, 13-Vertical movement assembly, 14-Worktable; 2-Machine tool connecting parts; 3-Spindle, 31-Inclined surface, 311-Mounting groove; 4-End mill; 5-Laser galvanometer assembly, 51-Laser galvanometer, 52-Ball gear connection transmission component, 521-Base, 522-Spherical part, 53-Upper ball cover, 54-Lower ball cover; 6-Thermal camera assembly; 7-Force gauge; 8-Drive component, 81-Drive gear, 82-Transmission shaft; 9 - Laser galvanometer scanning range; 10-Laser beam. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. In the following embodiments or examples, unless otherwise specified, the functional components or structures are conventional components or structures used in the art to achieve the corresponding functions.

[0034] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In the following embodiments, the laser galvanometer assembly 5 adopts a conventional structure in the art, so its specific structure and principle will not be described in detail. The following embodiments use the Xinzhiyuan Intelligent Technology XSS-10, whose maximum laser power is 1500W. The motor is a Mingzhi NEMA6 stepper motor. The thermal camera is a Raytron Technology Keen B615 short-wave infrared camera. The force gauge is a Qilasi 9170A rotary force gauge.

[0037] A laser-assisted milling head, connected to a machine tool 1 via a machine tool connector 2, is used for machining workpieces. The machining head includes: The spindle 3 is connected to the machine tool connector 2; A milling cutter 4 connected to the drive end of the spindle 3 and used for milling the workpiece; And a plurality of laser galvanometer assemblies 5 connected to the main shaft 3 and uniformly arranged around the central axis of the main shaft 3, wherein each laser galvanometer assembly 5 includes a laser galvanometer 51, and each group of laser galvanometer assemblies 5 is independently controlled.

[0038] In some specific embodiments, the laser galvanometer assembly 5 is provided with 2 to 5 groups.

[0039] In some specific embodiments, the laser galvanometer 51 is rotatably connected to the main shaft 3 via a ball gear transmission component 52; the ball gear transmission component 52 is driven to rotate by a drive component 8. The ball gear connecting transmission component 52 includes a base 521 and a ball part 522 that are fixedly connected, and the base 521 is fixedly connected to the laser galvanometer 51.

[0040] In some specific embodiments, the driving component 8 includes a motor and a driving gear 81. The driving gear 81 is connected to the transmission shaft 82 of the motor. The driving gear 81 meshes with the ball portion 522 of the ball gear connecting transmission component 52. The motor drives the driving gear 81 to rotate, thereby driving the ball gear connecting transmission component 52 to rotate.

[0041] In some specific embodiments, the spherical portion 522 is a spherical gear with external teeth formed on its surface. The external teeth on the surface of the spherical portion 522 are continuously distributed along its equatorial region or a specific latitude region, forming a spherical gear structure. The driving gear 81 is a cylindrical gear or a bevel gear, and its tooth profile is adapted to the external teeth of the spherical portion 522 to achieve meshing transmission.

[0042] In some specific embodiments, the main shaft 3 is provided with a plurality of evenly distributed inclined surfaces 31 in the circumferential direction, and the inclined surfaces 31 are provided with mounting grooves 311 for the ball portion 522 to be inserted. An upper ball cover 53 and a lower ball cover 54 are provided at the opening of the mounting groove 311. The upper ball cover 53 and the lower ball cover 54 are fixedly connected to the main shaft 3 and constrain the ball part 522 within the mounting groove 311, so that the ball gear connecting transmission component 52 and the main shaft 3 form a spherical pair constraint.

[0043] In some specific embodiments, with the vertical line of the inclined surface 31 as a reference, the rotation angle of the ball gear connecting transmission component 52 is -15° to 15°. The tilt angle of the inclined surface 31 is 0° to 45° with the vertical surface as the reference. When it is 0°, it means that the inclined surface 31 is vertical. Preferably, it is 30° to 45°.

[0044] In some specific embodiments, the processing head further includes a thermal camera assembly 6 disposed on the spindle 3 and used to acquire thermal images of the area to be processed of the workpiece; And / or, the machining head further includes a force measuring instrument 7 disposed at the top of the milling cutter 4 and used to acquire the cutting force signal of the milling cutter 4.

[0045] In some specific embodiments, the thermal camera assembly 6 is provided in several groups, the number of which corresponds to the number of the laser galvanometer assembly 5, with each group of thermal camera assembly 6 corresponding to one group of laser galvanometer assembly 5.

[0046] In some specific embodiments, the thermal camera assembly 6 is disposed on the lower surface of the main shaft 3 and located between adjacent laser galvanometer assemblies 5, and is evenly spaced around the central axis of the main shaft 3.

[0047] In some specific embodiments, one force gauge 7 is provided.

[0048] In some specific embodiments, the thermal camera assembly 6 and / or the force gauge 7 are connected to a controller, which is electrically connected to the milling cutter 4 and the laser galvanometer assembly 5.

[0049] In some specific embodiments, the control process of the controller is as follows: Acquire the thermal image of the area to be processed collected by the thermal camera assembly 6 and / or the cutting force signal collected by the force measuring instrument 7; The controller determines the current machining state based on the thermal image and / or the cutting force signal.

[0050] In some specific embodiments, the processing head is equipped with both a thermal camera assembly 6 and a force gauge 7. The thermal camera assembly 6 transmits the thermal image cutting force signal to the controller, and the force gauge 7 transmits the cutting force signal to the controller. When the highest temperature in the thermal image exceeds the material burn temperature threshold and the cutting force is less than 30% of the material's normal cutting force, it is judged as "excessive heat input, risk of overheating, or insufficient cutting force". When the highest temperature in the thermal image is less than 50% of the material burn temperature threshold and the deviation between the cutting force and the material's normal cutting force is within ±5%, it is judged as "insufficient heat input and excessive cutting force".

[0051] In some specific embodiments, the machine tool 1 has a feed mechanism that drives the machine tool connector 2 to move laterally and vertically.

[0052] A laser-assisted milling method, which uses a laser-assisted milling head for processing, includes the following steps: According to the location of the area to be processed, each of the laser galvanometer components 5 is independently controlled to open individually, partially and simultaneously, or all simultaneously, so that the opened laser galvanometer components 5 emit laser beams 10 to the corresponding circumferentially distributed area on the workpiece for preheating. The spindle 3 drives the milling cutter 4 to mill the area after synchronous preheating.

[0053] In some specific embodiments, when the area to be processed is a small local area or located at a specific circumferential angle, a laser galvanometer assembly 5 corresponding to that area is turned on separately to achieve precise and focused local preheating; When the area to be processed is a continuous and large range spanning multiple angles, multiple adjacent laser galvanometer assemblies 5 covering the range are opened simultaneously to achieve continuous and uniform preheating of the area and to match the feed path of the milling cutter 4. When it is necessary to preheat the workpiece uniformly in the whole or a large area of ​​the circumference, all laser galvanometer components 5 are turned on at the same time to achieve rapid and comprehensive circumferential heating without dead angles, so as to provide a uniform thermal environment for subsequent all-round milling.

[0054] In some specific embodiments, during the milling process, the opening state and laser parameters of the laser galvanometer assembly 5 are dynamically adjusted according to the real-time machining path to ensure that the material to be cut in front of the milling cutter 4 is always in the best preheated state, while avoiding overheating of the machined or unmachined areas.

[0055] Each of the above embodiments can be implemented individually or in any combination of two or more.

[0056] The following description uses specific examples to illustrate the point.

[0057] Example 1 like Figure 1 As shown, a laser-assisted milling head is connected to a machine tool 1 via a machine tool connector 2 and is used for machining workpieces. The machining head includes: The spindle 3 is connected to the machine tool connector 2; A milling cutter 4 connected to the drive end of the spindle 3 and used for milling the workpiece; And three sets of laser galvanometer assemblies 5 connected to the main shaft 3 and evenly arranged around the central axis of the main shaft 3, such as Figure 2 As shown, three sets of laser galvanometer assemblies 5 are evenly arranged around the central axis of the main shaft 3 at 120° intervals. Each laser galvanometer assembly 5 includes a laser galvanometer 51, and each set of laser galvanometer assemblies 5 is independently controlled.

[0058] In this embodiment, as Figure 3 As shown, the laser galvanometer 51 is rotatably connected to the main shaft 3 via a ball gear connecting transmission component 52. Figure 4 As shown, the ball gear connecting transmission component 52 includes an integrally formed base 521 and a ball portion 522, with the base 521 fixedly connected to the housing of the laser galvanometer 51. Figure 5 As shown, the spherical portion 522 is a spherical gear with continuous external teeth machined in its equatorial region. Three inclined surfaces 31 are evenly distributed circumferentially on the main shaft 3, with an inclination angle of 30° relative to the vertical plane. Each inclined surface 31 has a mounting groove 311. The spherical portion 522 is placed into the mounting groove 311 and fixedly connected to the main shaft 3 via an upper ball cover 53 and a lower ball cover 54, thereby constraining the spherical portion 522 within the mounting groove 311, forming a spherical pair that allows it to rotate around its center within a certain angle. A separate drive unit 8 is used to drive the spherical gear connecting transmission member 52 to rotate. The drive unit 8 includes a motor, on which a cylindrical gear-shaped drive gear 81 is mounted. This drive gear 81 meshes with the external teeth in the equatorial region of the spherical portion 522. When the stepper motor operates, the drive gear 81 rotates, driving the spherical gear connecting transmission member 52 to rotate around a horizontal axis (see [reference]) with the vertical line of the inclined surface 31 as a reference. Figure 3The axis (BB) is deflected within a range of ±15°, thereby adjusting the initial emission angle of the laser galvanometer 51 as a whole.

[0059] like Figure 6 As shown, the laser scanning coverage of the three lasers can be adjusted by controlling the ball gear connecting transmission component. Figure 6 When the rotation angle of the ball gear connecting transmission component 52 is -15°, the laser scanning coverage of the three lasers is the smallest. Figure 6 When the rotation angle of the ball gear connecting transmission component 52 is 0°, the laser scanning coverage of the three lasers is centered. (i.e., b1, b2, b3) Figure 6 When the rotation angle of the ball gear connecting transmission component 52 (i.e., c1, c2, c3) is 15°, the laser scanning coverage of the three lasers is at its maximum. The coverage of the three laser galvanometer assemblies 5 can be freely adjusted through the ball gear connecting transmission component 52, giving it better processing adaptability.

[0060] In this embodiment, the machine tool 1 is a three-axis linkage machine tool, which is a conventional structure in the art and does not involve innovation. The machine tool 1 includes: Rack 11; Lateral movement assembly 12 connected to and permissible with the frame 11; A vertical moving component 13 is disposed on the horizontal moving component 12, and the spindle 3 is mounted on the vertical moving component 13 via the machine tool connector 2, so that the spindle 3 can move horizontally and / or vertically.

[0061] In this embodiment, the lateral movement component 12 is an X-axis linear guide module, and the vertical movement component 13 is a Z-axis ball screw slide.

[0062] In this embodiment, the workpiece is placed on the worktable 14. The worktable 14 is mounted on the frame 11 and can move in a horizontal direction (i.e., the Y-axis direction) perpendicular to the moving direction of the transverse moving component 12. Specifically, the worktable 14 is mounted on the frame 11 via a set of Y-axis linear guides and a ball screw drive module. Through the Y-axis movement of the worktable 14, combined with the X and Z-axis movements of the spindle 3, the machining head can achieve workpiece positioning and complex trajectory machining in three-dimensional space (X, Y, Z directions).

[0063] A laser-assisted milling method using the machining head described in Example 1, taking the circumferential milling of the upper end face of a feature part of a nickel-based superalloy GH4169 casing as an example, includes the following steps: S1. Machining head installation and parameter setting: Install the machining head onto the three-axis linkage machine tool 1 via the machine tool connector 2. Based on the workpiece material (GH4169), tool parameters (diameter 8mm), and machining parameters (depth of cut 200μm, feed rate 300mm / min), preset the initial output power of a single laser galvanometer assembly 5 to 800W.

[0064] S2. Path Planning and Galvanometer Control: Based on the toolpath planned by the CNC program, the controller independently controls three sets of laser galvanometer assemblies 5 arranged around the spindle 3, which have three scenarios, such as... Figure 7 As shown: Scenario A (Local Finishing): When the milling cutter 4 mills a narrow groove along a straight path, the controller individually activates a single laser galvanometer assembly 5 in front of the cutter's forward direction to achieve focused, localized linear preheating, such as... Figure 7 As shown in Figure a, when the milling cutter 4 mills circumferentially, Figure 8 This demonstrates a scenario where the circumferential machining area is divided into three parts. Figure 8 In the middle, 'a' represents the milling process of the scanning area handled by the first galvanometer. Figure 8 In the middle, b represents the milling process of the scanning area handled by the second galvanometer. Figure 8 In the middle, c represents the milling process of the scanning area handled by the third galvanometer. Scenario B (Continuous Contour Milling): When the milling cutter 4 performs large-curvature contour milling, the preheating area needs to continuously cover the changing circumferential angle. The controller simultaneously activates two adjacent laser galvanometer assemblies 5 and overlaps their scanning areas on the machining path to achieve continuous relay preheating, such as... Figure 7 As shown in b; Scenario C (Large-area end face milling): When performing 360° full-coverage milling on the upper end face of the workpiece, the controller simultaneously activates all three sets of laser galvanometer assemblies 5 to achieve rapid and uniform preheating of the entire circumference, such as... Figure 7 As shown in c.

[0065] S3. Machining Execution: While the laser preheats the material in front of the tool, the spindle 3 drives the milling cutter 4 to mill the softened area at a set rotational speed (e.g., 5000 rpm) and feed rate. The machining of the entire feature is completed through the coordination of the Y-axis movement of the worktable 14 and the X and Z-axis movements of the spindle 3. This method, through independent and coordinated control of multiple galvanometers, effectively solves the problem of discontinuous and uneven laser heating in circumferential milling, achieving stable and efficient laser-assisted machining of GH4169 material.

[0066] Example 2 like Figure 9As shown, this embodiment is based on embodiment 1. On the lower surface of the main shaft 3, between adjacent laser galvanometer assemblies 5, three thermal camera assemblies 6 are also uniformly arranged circumferentially to monitor the thermal images of the corresponding laser beam 10 irradiated areas, as shown. Figure 10 As shown in the figure, a force gauge 7 is mounted on the top of the milling cutter 4 to collect cutting force signals in real time during the milling process. A controller (not shown in the figure) is electrically connected to the thermal camera assembly 6, the force gauge 7, the laser galvanometer assembly 5, and the machine tool spindle that drives the milling cutter 4, forming a closed-loop control system.

[0067] The control process of the controller is as follows: Acquire the thermal image of the area to be processed collected by the thermal camera assembly 6 and / or the cutting force signal collected by the force measuring instrument 7; The controller determines the current machining state based on the thermal image and / or the cutting force signal.

[0068] In this embodiment, the processing head is equipped with both a thermal camera assembly 6 and a force measuring instrument 7. The thermal camera assembly 6 transmits the thermal image cutting force signal to the controller, and the force measuring instrument 7 transmits the cutting force signal to the controller. When the highest temperature in the thermal image exceeds the material burn temperature threshold and the cutting force is less than 30% of the material's normal cutting force, it is judged as "excessive heat input, risk of overheating, or insufficient cutting force". When the highest temperature in the thermal image is less than 50% of the material burn temperature threshold and the cutting force is the same as the material's normal cutting force, it is judged as "insufficient heat input and excessive cutting force".

[0069] A laser-assisted milling method using the machining head described in Example 2 includes the following steps: S1. Initialization and Parameter Presetting: Install the machining head and preset the key process thresholds in the controller according to the workpiece material. For example, for nickel-based superalloy GH4169, set the material burn temperature threshold T. burn =1000℃, effective softening initiation temperature T of the material soft =600℃, reference cutting force F without laser assistance ref =100N.

[0070] S2. Machining Start-up and Online Monitoring: Upon starting machining, the controller adjusts the working mode (individual / partial / full) of the laser galvanometer assembly 5 according to the tool path. Simultaneously, the thermal camera assembly 6 acquires thermal images of the laser-irradiated area in real time, and the force gauge 7 acquires cutting force signals during the milling process in real time and feeds them back to the controller.

[0071] S3. State Determination and Adaptive Control: Based on real-time monitoring data, the controller executes the following closed-loop control logic: Overheating / burning risk: If the thermal image shows a maximum temperature T max > T burn (1000℃), and the cutting force F < 30%*F ref If the heat input is (30N), it is determined that "the heat input is too high and there is a risk of overheating". The operator should immediately reduce the laser power of the laser galvanometer assembly 5 that is in operation (for example, reduce it by 200-300W).

[0072] Insufficient preheating: If T max < 50% * T burn (500℃) or T max < T soft (600℃), and the cutting force F≈F ref If the heat input is less than 100N, it is determined that "the heat input is insufficient and the material is not softened sufficiently". The operator should increase the laser power of the corresponding laser galvanometer assembly 5 (for example, increase it by 200-300W).

[0073] State optimization: If T soft (600℃) ≤ T max ≤ T burn (1000℃), and F ref (100N) > F > 30%* F ref If (30N), it is determined that the processing status is "good" and the current laser power and processing parameters are maintained.

[0074] Multi-material processing case applications: Machining CMC (Ceramic Matrix Composite) head tapers: CMC material has extremely high hardness, requiring greater energy input. When using large-diameter tools (e.g., 20mm), the heat-affected zone width of a single 1500W galvanometer is insufficient. The controller instructs two adjacent galvanometers to simultaneously activate, each working collaboratively at 1200W power, expanding and homogenizing the preheating area to ensure complete coverage of the tool cutting width, achieving effective machining.

[0075] Processing CFRP (carbon fiber reinforced polymer) composite components: The CFRP resin matrix is ​​prone to thermal decomposition. During processing, a more conservative threshold (such as T) is used in the controller. burn =400℃). Even if the cutting force has a downward trend, as long as the thermal image shows a temperature close to 400℃, priority should be given to cooling (e.g., reducing the power from 300W to 200W) to strictly prevent material burn-off.

[0076] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A laser-assisted milling head, characterized in that, It is connected to the machine tool (1) via a machine tool connector (2) and is used to process workpieces. The processing head includes: The spindle (3) is connected to the machine tool connector (2); A milling cutter (4) connected to the drive end of the spindle (3) and used to mill the workpiece; And a plurality of laser galvanometer assemblies (5) connected to the main shaft (3) and uniformly arranged around the central axis of the main shaft (3), wherein each laser galvanometer assembly (5) includes a laser galvanometer (51), and each group of laser galvanometer assemblies (5) is independently controlled.

2. The laser-assisted milling head according to claim 1, characterized in that, The laser galvanometer (51) is rotatably connected to the main shaft (3) via a ball gear connecting transmission component (52), and the ball gear connecting transmission component (52) is driven to rotate by a driving component (8); The ball gear connecting transmission component (52) includes a fixedly connected base (521) and a ball part (522), wherein the base (521) is fixedly connected to the laser galvanometer (51).

3. The laser-assisted milling head according to claim 2, characterized in that, The main shaft (3) has several evenly distributed inclined surfaces (31) in its circumference, and the inclined surfaces (31) have mounting grooves (311) for the ball part (522) to be inserted. The mounting groove (311) is provided with an upper ball cover (53) and a lower ball cover (54). The upper ball cover (53) and the lower ball cover (54) are fixedly connected to the main shaft (3) and constrain the ball part (522) within the mounting groove (311), so that the ball gear connecting transmission component (52) and the main shaft (3) form a spherical pair constraint.

4. A laser-assisted milling head according to claim 3, characterized in that, With the vertical line of the inclined surface (31) as a reference, the rotation angle of the ball gear connecting transmission component (52) is -15° to 15°; The tilt angle of the inclined surface (31) is 0°~45° with the vertical surface as the reference.

5. A laser-assisted milling head according to claim 1, characterized in that, The processing head also includes a thermal camera assembly (6) mounted on the spindle (3) and used to acquire thermal images of the area to be processed of the workpiece. And / or, the machining head further includes a force measuring instrument (7) disposed at the top of the milling cutter (4) and used to acquire the cutting force signal of the milling cutter (4).

6. A laser-assisted milling head according to claim 5, characterized in that, The thermal camera assembly (6) and / or force gauge (7) are connected to a controller, which is electrically connected to the milling cutter (4) and the laser galvanometer assembly (5).

7. A laser-assisted milling head according to claim 6, characterized in that, The control process of the controller is as follows: Acquire the thermal image of the area to be processed collected by the thermal camera assembly (6) and / or the cutting force signal collected by the force measuring instrument (7); The controller determines the current machining state based on the thermal image and / or the cutting force signal; When the highest temperature in the thermal image exceeds the material burn temperature threshold and the cutting force is less than 30% of the material's normal cutting force, it is judged as "excessive heat input, risk of overheating, or insufficient cutting force"; When the highest temperature in the thermal image is less than 50% of the material burn temperature threshold and the deviation between the cutting force and the material's normal cutting force is within ±5%, it is judged as "insufficient heat input and excessive cutting force".

8. A laser-assisted milling head according to claim 1, characterized in that, The machine tool (1) has a feed mechanism that drives the machine tool connector (2) to move laterally and vertically.

9. A laser-assisted milling method, wherein the machining is performed using a laser-assisted milling head as described in any one of claims 1 to 8, characterized in that, Includes the following steps: According to the location of the area to be processed, each of the laser galvanometer components (5) is independently controlled to open, partially open or all open simultaneously, so that the opened laser galvanometer components (5) emit laser beams (10) to the corresponding circumferential distribution area on the workpiece for preheating; The spindle (3) drives the milling cutter (4) to mill the area after synchronous preheating.

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