Five-axis swinging head for aluminum alloy machining and working method

Abstract

The invention belongs to the technical field of aluminum alloy processing. The invention provides a five-axis swing head for aluminum alloy machining and a working method, relates to the field of precision machining equipment, and aims to solve the problems that an existing swing head is abraded in transmission, slag falls off, braking torque is insufficient, angle detection precision is low, and cables are prone to interference, and the five-axis swing head comprises a C-axis assembly, a B-axis assembly and an electric spindle; a C-axis shell is rigidly connected with a spindle box of the XYZ portal frame, and a C-axis servo motor drives the B-axis shell to rotate through a synchronous belt and a speed reducer; a B-axis servo motor drives a swing arm to swing through a synchronous belt and a speed reducer, an electric main shaft is fixedly installed on the swing arm, and a C-axis assembly and a B-axis assembly are each provided with an encoder to achieve angle closed-loop detection and are provided with a pneumatic brake disc for strengthening braking and a B-axis shell for integrating pipeline wiring, so that cable abrasion and movement interference are avoided, and the transmission stability and the machining precision are improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy processing technology, and in particular to a five-axis oscillating head and its working method for aluminum alloy processing. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the field of aluminum alloy processing, five-axis machining technology is widely used in aluminum profiles, curtain walls, and automotive parts due to its ability to handle complex curved surfaces and multi-angle machining requirements. Five-axis machining equipment, through the coordinated movement of multiple rotary and linear axes, enables the cutting tool to possess multi-degree-of-freedom machining capabilities, thereby significantly improving machining accuracy and efficiency. As the core component of five-axis machining equipment, the oscillating head's transmission accuracy, braking stability, angle detection accuracy, and wiring rationality on its B-axis and C-axis directly determine the final quality of aluminum alloy machining. In recent years, with the development of aluminum alloy processing towards high-end and precision, the performance requirements for the oscillating head have become increasingly stringent, demanding not only high transmission efficiency but also stability and reliability during long-term machining.

[0004] However, existing five-axis oscillating heads have many shortcomings in aluminum alloy machining. On the one hand, traditional transmission components are prone to wear and slag shedding, which not only affects the machining environment but also reduces transmission accuracy, making it difficult to meet the requirements of precision machining of aluminum alloys. On the other hand, the braking mechanism has insufficient torque, and the oscillating head angle is prone to deviation under high cutting forces in aluminum alloy machining scenarios, resulting in poor machining stability. In addition, angle detection is mostly based on single feedback, with limited accuracy; the pipeline routing mostly uses external cable chains, which are prone to problems such as cable wear and motion interference, increasing equipment maintenance costs and failure risks. At the same time, some oscillating head layouts are not compact enough, resulting in low transmission efficiency and insufficient component durability. Frequent component replacements seriously affect the production efficiency of aluminum alloy machining. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a five-axis oscillating head and its working method for aluminum alloy processing. This reduces the space occupied during movement, lowers the risk of interference between components, provides a stable basic transmission guarantee for precision aluminum alloy processing, reduces production stoppages caused by low transmission efficiency, avoids the hassle of frequently replacing worn transmission components, and effectively improves the overall production efficiency of aluminum alloy processing.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a five-axis oscillating head for aluminum alloy machining.

[0007] A five-axis oscillating head for aluminum alloy machining includes a B-axis assembly, a C-axis assembly, and an electric spindle; The C-axis assembly includes a C-axis housing, a C-axis servo motor, a C-axis drive pulley, a C-axis synchronous belt, a C-axis driven pulley, and a C-axis reducer. The C-axis housing is rigidly connected to the spindle box of the XYZ gantry via a flange. The fixed ends of the C-axis servo motor and the C-axis reducer are both fixed to the C-axis housing. The output end of the C-axis servo motor is connected to the C-axis drive pulley, which is then connected to the C-axis driven pulley via the C-axis synchronous belt. The C-axis driven pulley is fixedly connected to the input end of the C-axis reducer, and the output end of the C-axis reducer is rigidly connected to the B-axis housing of the B-axis assembly. The B-axis assembly includes a B-axis housing, a B-axis servo motor, a B-axis drive pulley, a B-axis synchronous belt, a B-axis driven pulley, a B-axis reducer, a B-axis encoder, a reducer side support plate, and a swing arm. The fixed ends of the B-axis servo motor and the B-axis reducer are fixed to the B-axis housing. The output end of the B-axis servo motor is connected to the B-axis drive wheel, which is connected to the B-axis driven wheel via the B-axis synchronous belt. The B-axis driven wheel is fixed to the input end of the B-axis reducer. The output end of the B-axis reducer is fixedly connected to the reducer side support plate. The reducer side support plate is fixedly connected to the swing arm. The electric spindle is fixed on the swing arm.

[0008] In one implementation of the first aspect of the present invention, the C-axis assembly further includes a C-axis encoder, the C-axis encoder stator is fixedly mounted on the C-axis housing via a C-axis encoder bracket, and the C-axis encoder rotor is coaxially fixedly connected to the C-axis driven wheel.

[0009] In one implementation of the first aspect of the present invention, the C-axis assembly further includes a C-axis pneumatic brake disc, which is mounted between the output end of the C-axis reducer and the B-axis housing.

[0010] In one implementation of the first aspect of the present invention, the B-axis assembly further includes a B-axis encoder, the rotor of which is fixed on a second encoder bracket, the second encoder bracket is mounted on a swing arm and rotates with it, the stator of which is mounted on a first encoder bracket, and the first encoder bracket is mounted together with a support sleeve and fixed on the B-axis housing.

[0011] In one implementation of the first aspect of the present invention, the B-axis assembly further includes a B-axis pneumatic brake disc, which is mounted between the output end of the B-axis reducer and the side support plate of the reducer.

[0012] In one implementation of the first aspect of the present invention, the B-axis housing and the C-axis housing integrate wiring and conduits, which are centrally routed through a dedicated sleeve.

[0013] In one implementation of the first aspect of the present invention, the second encoder bracket rotates with the swing arm, and the first encoder bracket is fixed on the support sleeve of the B-axis housing.

[0014] In one implementation of the first aspect of the present invention, the C-axis encoder bracket is fixed inside the C-axis housing, and the rotor of the C-axis encoder rotates with the C-axis driven wheel.

[0015] In one implementation of the first aspect of the present invention, the electric spindle is used to mount cutting tools and cooperates with the B-axis, C-axis and XYZ three-axis gantry feed to achieve five-axis machining of aluminum alloys.

[0016] Secondly, the present invention provides a five-axis oscillating head working method for aluminum alloy processing.

[0017] A five-axis oscillating head working method for aluminum alloy machining, utilizing the five-axis oscillating head for aluminum alloy machining according to the first aspect of the present invention, includes the following process: The C-axis housing is rigidly fixed to the gantry spindle box, and linear feed is achieved along the XYZ axes of the gantry. The C-axis servo motor starts, driving the C-axis drive wheel, which transmits the power through the C-axis synchronous belt and C-axis driven wheel to the C-axis reducer, causing the B-axis housing and the B-axis assembly and electric spindle mounted on it to rotate around the C-axis. The C-axis encoder provides real-time feedback of the rotation angle and corrects position deviations based on the feedback signal. The B-axis servo motor starts, driving the B-axis drive wheel, which transmits the power through the B-axis synchronous belt and B-axis driven wheel to the B-axis reducer, causing the B-axis swing arm and electric spindle to swing around the B-axis. The B-axis encoder provides real-time feedback of the swing angle, and corrects position deviations based on the feedback signal. After the positional deviation of the C-axis assembly and the B-axis assembly is adjusted to the correct position, the C-axis pneumatic brake disc and the B-axis pneumatic brake disc are respectively tightened to a fixed angle. The electric spindle starts and, in conjunction with the linear feed of the XYZ axes of the gantry, completes the five-axis linkage machining of the aluminum alloy workpiece.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a servo motor-synchronous belt-reducer transmission logic for both the C and B axes, forming a coordinated five-axis motion system. The compact layout reduces space occupation and the risk of interference between components, providing a stable foundation for precision aluminum alloy machining. It also reduces production stoppages caused by low transmission efficiency, avoids the hassle of frequent replacement of worn transmission components, and effectively improves the overall production efficiency of aluminum alloy machining. This invention solves the core technical problems of easy wear and slag shedding and low transmission efficiency caused by loose layout in existing five-axis oscillating head transmission components. It overcomes the shortcomings of traditional transmission structures, such as rapid accuracy decay and large power transmission losses, improving the transmission stability and power transmission efficiency of the oscillating head and preventing contamination of the machining environment by impurities caused by wear of transmission components.

[0019] This invention uses a C-axis encoder to collect the rotation angle of the C-axis drive chain in real time and a B-axis encoder to dynamically capture the swing angle of the swing arm, forming a closed-loop feedback control throughout the entire stroke. This ensures that the swing head can correct angle deviations in a timely manner during aluminum alloy processing, avoiding dimensional errors caused by inaccurate angle detection. It provides a reliable angle control basis for processing complex shapes of aluminum alloys, reduces the scrap rate caused by angle deviations, lowers processing costs, and improves the dimensional consistency of batch processing. It meets the precision requirements of aluminum alloy precision machining, solves the technical problems of existing five-axis swing head angle detection, which is mostly single feedback and has limited accuracy, overcomes the defects of angle detection lag and deviation accumulation, and improves the angle detection accuracy and real-time feedback of the B-axis and C-axis.

[0020] This invention designs a dual-axis braking scheme. The C-axis pneumatic brake disc is mounted between the output end of the C-axis reducer and the B-axis housing, and the B-axis pneumatic brake disc is mounted between the output end of the B-axis reducer and the reducer side support plate. This solves the technical problems of insufficient torque in existing five-axis sway head braking structures and cable wear and motion interference caused by external cable carriers. It overcomes the defects of easy sway head angle deviation and easy cable damage under large cutting forces, improves the reliability of sway head braking and cable service life. The dual-axis pneumatic brake discs provide stable braking torque, ensuring that the sway head angle can be firmly maintained under large cutting force scenarios in aluminum alloy processing, avoiding poor processing stability caused by angle deviation. At the same time, the integrated cable routing design replaces the traditional external cable carrier, avoiding cable entanglement, wear and motion interference, reducing equipment maintenance costs and failure risks, extending component durability, avoiding production interruptions caused by cable failure or brake failure, and further ensuring the continuous production efficiency of aluminum alloy processing.

[0021] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 A schematic diagram of the structure of a five-axis oscillating head for aluminum alloy processing provided as an exemplary embodiment of the present invention; Figure 2 A schematic diagram of C-axis rotation is provided for an exemplary embodiment of the present invention; Figure 3 A schematic diagram of B-axis rotation is provided for an exemplary embodiment of the present invention; The components are as follows: 1. C-axis housing; 2. C-axis servo motor; 3. C-axis drive pulley; 4. C-axis synchronous belt; 5. C-axis driven pulley; 6. C-axis RV reducer; 7. C-axis encoder; 8. C-axis pneumatic brake disc; 9. B-axis housing; 10. Electric spindle; 11. B-axis servo motor; 12. B-axis drive pulley; 13. B-axis synchronous belt; 14. B-axis driven pulley; 15. B-axis RV reducer; 16. B-axis encoder; 17. B-axis pneumatic brake disc; 18. Reducer side support plate; 19. Swing arm; 20. Support sleeve; 21. First encoder bracket; 22. Second encoder bracket; 23. C-axis encoder bracket. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] In high-end equipment fields such as aerospace, automobile manufacturing, and medical devices, aluminum alloys are widely used due to their advantages such as lightweight, high strength, and corrosion resistance. However, the processing of complex components such as integral impellers and irregular curved surface parts places stringent requirements on the multi-axis linkage accuracy and motion stability of the equipment. Traditional five-axis oscillating heads often have problems such as structural conflicts between "fixed and rotating", unclear connection logic between the B-axis and C-axis, and poor coordination with the gantry, resulting in insufficient processing accuracy and shortened equipment life. In view of this, this implementation innovatively designs a five-axis oscillating head for aluminum alloy processing. The C-axis assembly uses the C-axis housing as a static support carrier and is directly rigidly connected to the gantry. The B-axis assembly uses the B-axis housing as a rotating carrier and achieves power transmission and relative rotation with the C-axis assembly through the output end of the C-axis RV reducer. The B-axis assembly completes the oscillating motion on its own housing, ultimately forming a five-axis linkage system of "gantry XYZ linear feed + C-axis rotation + B-axis oscillation". This design solves structural conflicts and ensures processing accuracy and stability through a high-precision transmission chain, closed-loop control and reliable braking mechanism, which can meet the precision processing requirements of complex aluminum alloy components.

[0027] In this implementation, the C-axis assembly is a "static support unit" that is fixed to the gantry and provides C-axis rotational drive force output; the B-axis assembly is a "rotation-oscillation composite unit" that rotates with the C-axis using the B-axis housing as a carrier, while independently oscillating in the B-axis; the electric spindle is a "cutting execution unit" that is fixed to the front end of the B-axis swing arm and completes cutting with the movement of the B / C axes and the XYZ axis feed. The overall layout of this invention is compact, with no interference between the strokes of each motion axis. The C-axis rotation range is 0°~360°, and the B-axis oscillation range is -90°~+90°, meeting the posture adjustment requirements for complex curved surface machining.

[0028] In this implementation, the C-axis assembly is the core connection between the oscillating head and the gantry frame, and also provides rotational power around the vertical C-axis. Its structural features are "stationary housing + rotational transmission chain", as follows: Figure 1 As shown, the connection relationships of each component are as follows: The C-axis housing 1, serving as the basic support for the C-axis assembly, is welded from low-alloy high-strength steel, possessing excellent rigidity and resistance to deformation. After welding, it undergoes overall stress-relief annealing to eliminate residual welding stress and prevent deformation during long-term use. Optionally, the top of the C-axis housing 1 is machined with a flange connection surface, rigidly connected to the gantry spindle box via high-strength bolts. The bolts are evenly distributed, and the preload torque is calibrated to ensure no relative displacement at the connection point. The first-order natural frequency is ≥500Hz, meeting the rigidity requirements of high-speed machining. The internal partitions of the C-axis housing 1 include mounting bases for the C-axis servo motor 2, the C-axis RV reducer 6, and the C-axis encoder 7. Each mounting surface is precision milled, with a flatness ≤0.01mm / 100mm and a perpendicularity ≤0.015mm, providing a high-precision mounting reference for internal components.

[0029] In this implementation, the fixed ends of the C-axis servo motor 2 and the C-axis RV reducer 6 are rigidly fixed to the C-axis housing 1, forming a static support foundation. The output end of the C-axis servo motor 2 is connected to the C-axis drive pulley 3 via a flat key, and the power is transmitted to the C-axis driven pulley 5 via the C-axis synchronous belt 4. The C-axis driven pulley 5 is fixedly connected to the input end of the C-axis RV reducer 6, and the output end of the C-axis RV reducer 6 is rigidly connected to the B-axis housing 9. This transmission chain adopts a combination of "servo motor-synchronous belt-RV reducer". The C-axis synchronous belt 4 has buffering and vibration reduction characteristics, while the C-axis RV reducer 6 ensures high transmission accuracy and high torque output. The two work together to achieve a power transmission effect of "high-speed response + high precision + high torque".

[0030] In this implementation, the stator of the C-axis encoder 7 is fixed to the stationary end of the C-axis housing 1, and the rotor of the C-axis encoder 7 is coaxially fixed to the C-axis driven wheel 5 through the C-axis encoder bracket 23. The rotation angle signal of the transmission chain is collected in real time to provide closed-loop feedback for the CNC system, ensuring that the C-axis rotation angle accuracy is ≤0.005°. The C-axis pneumatic brake disc 8 is assembled between the output end of the C-axis RV reducer 6 and the B-axis housing 9. It is a normally closed structure. After the angle is adjusted to the correct position, it is vented and braked. The braking torque is ≥1500 N·m, the response time is ≤0.1s, effectively preventing inertial rotation, and the angle holding accuracy is ≤0.002°.

[0031] In this implementation, the B-axis assembly uses the B-axis housing 9 as its core carrier, rotates around the C-axis along with the output end of the C-axis assembly, and simultaneously independently oscillates around the horizontal axis of the B-axis. Its structural features are "rotating carrier + oscillating transmission chain," and the connection relationships of each component are as follows: The B-axis housing 9, serving as the integrated carrier for the B-axis assembly, is die-cast from ZL201 aluminum alloy. The die-casting process ensures a dense structure and lightweight design. After die-casting, it undergoes T6 heat treatment for solution treatment and artificial aging, achieving a tensile strength ≥320MPa and a yield strength ≥280MPa. This reduces overall weight while maintaining rigidity, thus minimizing the rotational load on the C-axis. The left side of the housing has a flange surface machined to mate with the output end of the C-axis RV reducer 6, with a clearance ≤0.01mm to ensure smooth power transmission. Inside the housing are mounting bases for the B-axis servo motor 11 and the B-axis RV reducer 15, as well as wiring channels. The parallelism of each mounting surface is ≤0.015mm / length, and the channel diameter is ≥30mm, facilitating wiring integration and cable avoidance during movement.

[0032] The fixed ends of the B-axis servo motor 11 and the B-axis RV reducer 15 are fixed to the B-axis housing 9 and rotate synchronously with the housing. The output end of the B-axis servo motor 11 is connected to the B-axis drive wheel 12 via a flat key, and the power is transmitted to the B-axis driven wheel 14 via the B-axis synchronous belt 13. The B-axis driven wheel 14 is fixedly connected to the input end of the B-axis RV reducer 15. The output end of the B-axis RV reducer 15 is welded to the reducer side support plate 18. The reducer side support plate 18 is then connected to the B-axis swing arm 19 by bolts. The output torque of the B-axis RV reducer 15 is ≥1400 N·m, which meets the swing load requirements of the B-axis swing arm 19 and the electric spindle 10.

[0033] In this implementation, the rotor of the B-axis encoder 16 is fixed to the moving end of the B-axis swing arm 19 via the second encoder bracket 22, and the stator of the B-axis encoder 16 is fixed to the carrier end of the B-axis housing 9 via the first encoder bracket 21 and the support sleeve 20. During the swing, the angle signal is collected in real time to form a closed-loop control. The swing angle accuracy is ≤0.005°. The B-axis pneumatic brake disc 17 is assembled between the output end of the B-axis RV reducer 15 and the reducer side support plate 18. It has the same structure as the C-axis pneumatic brake disc 8. After the swing is in place, it is braked and fixed. The angle maintenance accuracy is ≤0.002°, ensuring the stability of the tool posture during the cutting process.

[0034] The B-arm swing arm 19 is made of 6061-T6 aluminum alloy forging. The forging process ensures that the component has a dense structure and uniform mechanical properties. After T6 heat treatment, the tensile strength is ≥300MPa. The front end of the swing arm 19 is machined with a mounting flange for the electric spindle 10. The flatness of the flange surface is ≤0.005mm, and the perpendicularity is ≤0.008mm. The electric spindle 10 is rigidly fixed to the B-arm swing arm 19 through the front flange. The pre-tightening torque of the connecting bolts has been calibrated to ensure that there is no relative displacement between the electric spindle 10 and the B-arm swing arm 19, and the radial runout of the mating surface is ≤0.005mm.

[0035] In this implementation, a dedicated wiring channel is designed inside the B-axis housing 9, integrating the power cable of the electric spindle 10, the cable of the C-axis servo motor 2, the cable of the B-axis servo motor 11, the signal cable of the C-axis encoder 7, the signal cable of the B-axis encoder 16, and the air pipes of the C-axis pneumatic brake disc 8 and the B-axis pneumatic brake disc 17. The cables are high-flexibility drag chain cables, with a bending resistance of ≥10 million cycles. The air pipes are made of PU material, possessing wear-resistant and aging-resistant properties. All lines and pipes are centrally laid through PA66 nylon conduits as defined in claim 8, with power cable conduits, signal cable conduits, and pneumatic pipe conduits arranged according to functional zones. The minimum spacing between conduits is ≥5mm to avoid electromagnetic interference between power cables and signal cables, and to prevent pipe entanglement or wear during movement. After the lines are led out from the B-axis housing 9, they are connected to the fixed lines in the C-axis housing 1 via a rotary joint. The rotary joint supports 360° infinite rotation with a leakage rate ≤0.1L / min, ensuring the reliability of the line connection and the flexibility of movement.

[0036] In this implementation, the C-axis housing 1 is rigidly connected to the XYZ gantry spindle box via a top flange. The gantry spindle box is the core actuator for XYZ axis feed: the X-axis feeds along the length of the gantry beam, the Y-axis feeds along the width of the beam, and the Z-axis feeds vertically. All three axes use precision ball screw drives, with a positioning accuracy of ±0.01mm and a repeatability of ±0.008mm. After the five-axis tilting head is fixed, it achieves linear feed in the XYZ directions along with the spindle box. Simultaneously, angle adjustment is achieved through C-axis rotation and B-axis oscillation, ultimately forming a five-axis linkage of X / Y / Z / B / C, meeting the multi-pose machining requirements of complex aluminum alloy components.

[0037] The specific working principle is as follows: After the CNC system issues a C-axis rotation command, the C-axis servo motor 2 starts, and its output torque is transmitted to the C-axis drive wheel 3 via a flat key, and then to the C-axis driven wheel 5 via the C-axis synchronous belt 4. The C-axis driven wheel 5 drives the input end of the C-axis RV reducer 6 to rotate. The C-axis RV reducer 6 reduces the speed and amplifies the torque, then drives the B-axis housing 9 and the B-axis assembly and electric spindle 10 to rotate around the C-axis via its output end. During the rotation, the C-axis encoder 7 collects angle signals in real time and transmits them to the CNC system. The system calculates the position deviation using a PID algorithm and dynamically adjusts the output of the C-axis servo motor 2 to form a closed-loop control. When the target angle is reached, the system issues a braking command, the C-axis pneumatic brake disc 8 is vented and tightened, fixing the position of the B-axis housing 9 and completing the C-axis angle adjustment. The C-axis rotation speed range is 0~30 r / min, which can be steplessly adjusted by the CNC system according to machining requirements.

[0038] After the CNC system issues a B-axis swing command, the B-axis servo motor 11 starts, and the output torque is transmitted to the B-axis RV reducer 15 via the B-axis drive wheel 12, B-axis synchronous belt 13, and B-axis driven wheel 14. The output end of the B-axis RV reducer 15 drives the reducer side support plate 18 and the B-axis swing arm 19 to swing around the B-axis. During the swing, the B-axis encoder 16 collects the swing angle signal in real time and feeds it back to the CNC system for deviation correction to ensure swing accuracy. After swinging to the target angle, the B-axis pneumatic brake disc 17 is vented and braked to fix the position of the B-axis swing arm 19. The B-axis swing speed range is 0~20° / s, and the swing angle range is -90°~+90°, which can cover the processing posture requirements of most complex aluminum alloy components.

[0039] The five-axis oscillating head is fixed to the gantry spindle box via the C-axis housing 1. It achieves linear feed in the XYZ directions along the spindle box. The X-axis feeds along the gantry beam, the Y-axis feeds laterally along the spindle box, and the Z-axis moves up and down vertically. All three axes are driven by servo motors with precision ball screws. The maximum feed speeds can reach 20m / min, 15m / min, and 10m / min respectively, with a positioning accuracy of ±0.01mm, providing a high-precision linear feed foundation for five-axis linkage.

[0040] To achieve high-precision machining of complex curved surfaces of aluminum alloys, this invention may optionally employ a five-axis linkage kinematic model based on a homogeneous transformation matrix to establish a mapping relationship between the machine tool coordinate system and the workpiece coordinate system, as follows: Coordinate system definition: The origin of the machine tool coordinate system O-XYZ is located at the center of the gantry worktable, the X-axis is along the length of the crossbeam, the Y-axis is along the width of the crossbeam, and the Z-axis is vertically upward; the C-axis rotary coordinate system O1-X1Y1Z1 rotates around the Z-axis with a rotation angle of γ; the B-axis oscillating coordinate system O2-X2Y2Z2 oscillates around the X1 axis with an oscillation angle of β; the origin of the tool coordinate system O3-X3Y3Z3 is located at the tool tip, and the Z3 axis coincides with the axis of the electric spindle 10 along the tool axis.

[0041] Homogeneous transformation matrix: The homogeneous transformation matrix of a five-axis linkage is the product of the transformation matrices of each axis, i.e.: ; in, Let XYZ be the translation transformation matrix. Associating the C-axis rotation transformation matrix with the drive angle of the C-axis servo motor 2, Associating the B-axis rotation transformation matrix with the drive angle of B-axis servo motor 11, This is the tool offset transformation matrix. This matrix can be used to realize the coordinate transformation from any point in the workpiece coordinate system to the machine tool coordinate system, providing a theoretical basis for interpolation calculation in CNC systems.

[0042] Interpolation and Control: The CNC system employs the NURBS non-uniform rational B-spline interpolation algorithm to discretize the complex surface of the CAD model into minute line segments. Through look-ahead processing, the curvature of these segments is analyzed, and the feed rate is dynamically adjusted to ensure smooth cutting. The system uses inverse kinematics to decompose the surface machining path into displacements along the XYZ axes and angular changes along the B / C axes. The interpolation cycle is 0.1 ms, the interpolation accuracy is ≤0.001 mm, and the synchronization error of each axis is ≤0.01 mm.

[0043] Optionally, the five-axis linkage control of the present invention adopts a "master-slave control + closed-loop feedback" architecture, with the following core components: Main controller: It adopts an industrial-grade high-end CNC system, equipped with a high-performance processor and large-capacity storage, and supports functions such as multi-axis synchronous control, 3D graphics simulation, and parametric programming. It can process machining data of complex curved surfaces in real time.

[0044] Servo drive module: It adopts a vector control type servo driver, which is matched with the C-axis servo motor 2, the B-axis servo motor 11 and the XYZ-axis servo motors respectively. The control cycles of the current loop, speed loop and position loop are 0.02ms, 0.1ms and 0.1ms respectively, ensuring that the motor responds quickly and runs smoothly.

[0045] Feedback module: The signals from the C-axis encoder 7, B-axis encoder 16, and XYZ-axis grating ruler are transmitted to the main controller in real time via a high-speed industrial bus with a transmission rate ≥100Mbps and a delay ≤1ms, ensuring the real-time performance and accuracy of angle and position feedback.

[0046] Safety control module: Integrates safety functions such as safety torque shutdown (STO) and safety stop (SS1). When overload, overtravel, emergency stop or other abnormalities occur, the torque of C-axis servo motor 2, B-axis servo motor 11 and XYZ-axis servo motors is immediately cut off, and C-axis pneumatic brake disc 8 and B-axis pneumatic brake disc 17 are simultaneously tightened to prevent equipment damage and personnel injury.

[0047] The five-axis oscillating head of this invention, in conjunction with a gantry frame, can be widely used in the processing of complex aluminum alloy components in fields such as aerospace, automotive manufacturing, and medical devices. The following detailed description includes three typical examples: Case 1: Irregularly shaped curved fan frame for casement window (curved + beveled corner + rounded corner transition structure).

[0048] Workpiece shape and characteristics: Made of 6063-T5 aluminum alloy, used for high-end casement window sash frames. The overall structure is "rectangular + 1 / 4 arc at both ends", with a total length of 1800mm. The rectangular section is 60mm×45mm, and the arc section has a radius of curvature R200mm. Both ends need to be machined with 45° beveled corners (for splicing). There are two sealing grooves (5mm wide and 8mm deep) on the inner side of the sash frame, and the four outer corners are rounded with R5mm. The dimensional tolerance is ±0.03mm, the arc profile is ≤0.05mm, the beveled corner perpendicularity is ≤0.02mm, and the surface roughness Ra is ≤0.8μm. Batch processing is required (500 pieces per batch).

[0049] The processing flow, specifically, includes: For roughing, use a φ12mm carbide end mill (4-flute, sharp cutting edge to prevent sticking); for semi-finishing, use a φ8mm carbide ball end mill; for finishing, use a φ6mm diamond-coated ball end mill; and for machining sealing grooves, use a φ5mm solid carbide groove cutter (5mm cutting width, 10mm cutting length).

[0050] Roughing: Employing a "layered milling + curve following" strategy, the Z-axis depth of cut is 2mm / cut, the X / Y axis feed rate is 8m / min, and the electric spindle speed is 6000r / min. Through 360° C-axis rotation combined with ±30° B-axis oscillation, the material follows the straight and curved sections of the fan frame contour, quickly removing the blank allowance (leaving a 0.3mm finishing allowance) and avoiding overcutting at the junction of straight lines and curves.

[0051] Semi-finishing: The "contour fitting + angle correction" strategy is adopted. The Z-axis cutting depth is 0.3mm / time, the feed rate is 5m / min, the electric spindle speed is 9000r / min, and the B-axis dynamically adjusts the tool posture based on the rotation angle fed back in real time by the C-axis encoder, so that the tool always has an angle ≤8° with the tangent of the sector frame contour, corrects the arc contour error, and reserves 0.1mm finishing allowance.

[0052] Finishing: This process consists of three steps: ① Fine milling of straight and arc segments, with a Z-axis depth of cut of 0.1mm / cut, a feed rate of 3m / min, and an electric spindle speed of 15000r / min. The smoothness of the arc is ensured by using a NURBS interpolation algorithm. ② 45° bevel machining, with the C-axis rotating to position the bevel direction and the B-axis swinging to 45°. The bevel is then completed in conjunction with the Z-axis feed. The perpendicularity of the bevel is controlled by a closed-loop encoder on the B-axis. ③ Sealing groove machining, with the C-axis rotating and the X-axis feed moving synchronously. The B-axis swings to the direction of the groove machining to ensure uniform groove depth (8±0.02mm) and groove width tolerance of ±0.01mm.

[0053] Rounded corner transition: Select a φ5mm ball end mill, swing the B-axis to the rounded corner normal direction, slowly rotate the C-axis (5r / min), and cooperate with the Z-axis micro-feed to complete the R5mm rounded corner finishing to avoid burrs.

[0054] Case 2: Hollow insulated track for sliding doors (multi-cavity + stepped groove + drainage hole structure).

[0055] Workpiece shape and characteristics: Made of 6061-T6 aluminum alloy, used for the bottom track of heavy-duty sliding doors, with a total length of 2400mm and a "three-cavity" structure (width 120mm, height 80mm); the upper surface has two stepped grooves (main track groove 15mm wide, depth 20mm, secondary track groove 12mm wide, depth 18mm), drainage holes on both sides (φ8mm, spacing 300mm), and an internal heat insulation strip mounting groove (width 14mm, depth 60mm, at a 45° angle with the cavity); dimensional tolerance ±0.04mm, stepped groove parallelism ≤0.02mm / m, drainage hole position accuracy ≤0.05mm, surface roughness Ra≤1.0μm.

[0056] The processing flow, specifically, includes: For roughing, use a φ16mm carbide end mill (5-flute, with chip flute); for semi-finishing, use a φ10mm carbide end mill; for finishing stepped grooves, use φ12mm or φ15mm diamond-coated end mills; for machining heat insulation grooves, use a φ14mm long-neck end mill (70mm cutting length); and for machining drainage holes, use a φ8mm carbide drill bit (with internal cooling channel).

[0057] Roughing: A "layered depth reduction + zoned roughing" strategy is adopted, dividing the track section into 3 cavity areas. The Z-axis cutting depth is 3mm / stroke, the X / Y axis feed rate is 10m / min, and the electric spindle speed is 5000r / min. The C-axis rotation combined with the long-stroke X-axis feed quickly removes the excess material inside the cavity (leaving a 0.5mm semi-finishing allowance) to avoid cavity wall deformation.

[0058] Semi-finishing: ① Pre-machining of stepped grooves: C-axis fixed at 0°, B-axis swinging to 0°, and Z-axis feed to machine the rough contour of the main and auxiliary track grooves, leaving a 0.2mm finishing allowance; ② Machining of heat insulation strip grooves: C-axis rotated 90°, B-axis swinging to 45°, using a long-neck end mill, feed from one end of the track, and machine a 45° heat insulation strip mounting groove along the length of the cavity. The tool overhang length is 65mm, and the angle is corrected in real time by the B-axis encoder to avoid the groove wall tilting.

[0059] Finishing: ① Stepped groove milling: B-axis returns to 0°, C-axis is fixed, adopting the strategy of "side wall milling + groove bottom leveling", Z-axis cutting depth 0.2mm / time, feed speed 4m / min, electric spindle speed 12000r / min, ensuring groove wall perpendicularity ≤0.01mm, parallelism ≤0.015mm / m; ② Cavity finishing: C-axis rotates 180°, B-axis swings to -45°, finish milling the other side cavity wall and heat insulation groove, ensuring the three cavities are symmetrical in size; ③ Drainage hole machining: C-axis rotates to position the circumference of the drainage hole, B-axis swings to 90° (drill bit perpendicular to the track surface), C-axis pneumatic brake disc is tightened and positioned, Z-axis feeds and drills, the hole position is controlled by the X-axis feed amount (300mm interval) and C-axis angle, ensuring the drainage hole penetrates the cavity vertically.

[0060] Deburring: Use a φ10mm nylon brush, swing the B-axis to 30°, rotate the C-axis (10r / min), and feed along the X-axis to remove burrs from the grooves and holes, avoiding scratching the pulleys and sealing strips.

[0061] Case 3: Thermally broken aluminum composite sealing pressure line (complex cross section + snap groove + rounded edge structure).

[0062] Workpiece shape and characteristics: Material: 6063-T5 aluminum alloy; used for fixing pressure lines on the glass of thermally broken aluminum windows and doors; total length: 1500mm; cross-section: irregular and complex shape (width: 35mm, height: 25mm); inner side has glass slots (width: 8mm, depth: 12mm, forming a 15° angle with the pressure line); outer side has two buckle slots (width: 3mm, depth: 5mm, used for installing sealing strips); edge is R3mm rounded; dimensional tolerance: ±0.02mm; buckle slot spacing tolerance: ±0.01mm; glass slot angle tolerance: ±0.2°; surface roughness Ra≤0.6μm (appearance requirements).

[0063] The processing flow, specifically, includes: For roughing, use an 8mm carbide end mill (3-flute); for semi-finishing, use a 6mm carbide ball end mill; for glass slot machining, use an 8mm form end mill (15° cutting edge angle); for buckle slot machining, use a 3mm solid carbide slot end mill; and for rounded edge machining, use a 3mm diamond-coated ball end mill.

[0064] Roughing: Employing a "section-by-section milling" strategy, the feed proceeds along the length of the pressure line (X-axis), with a Z-axis depth of cut of 1mm / cut, a feed rate of 6m / min, and an electric spindle speed of 7000r / min. The C-axis rotation, combined with the B-axis ±15° oscillation, rapidly removes the blank allowance (leaving a 0.2mm finishing allowance) following the complex cross-sectional contour, completing the rough profile machining in one pass without changing the clamping angle.

[0065] Semi-finishing: A "contour fitting + groove pre-machining" strategy is adopted, with a Z-axis depth of cut of 0.2 mm / cut, a feed rate of 4 m / min, and an electric spindle speed of 10000 r / min. The tool posture is adjusted by B-axis oscillation, and the glass slot and snap-fit ​​slot are pre-machined separately to correct the cross-sectional contour error and reserve a finishing allowance of 0.1 mm.

[0066] Finishing: ① Outer surface and arc edge: Swing the B-axis to the normal direction of the arc edge, slowly rotate the C-axis (8r / min), and with the X-axis feed, use a φ3mm ball end mill to finish mill the R3mm arc edge and outer surface to ensure a smooth surface without tool marks; ② Glass slot: Fix the C-axis, swing the B-axis to 15°, select a forming end mill, and feed along the X-axis to machine the slot. The slot angle is controlled by the B-axis encoder in a closed loop (15°±0.05°), and the slot width is 8±0.01mm; ③ Clip slot: Return the B-axis to 0°, rotate the C-axis 180°, and use a φ3mm slot end mill to machine two clip slots with a slot depth of 5±0.008mm. Control the slot spacing tolerance to ±0.009mm through the X-axis feed.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 five-axis oscillating head for aluminum alloy machining, characterized in that, Includes B-axis assembly, C-axis assembly, and electric spindle; The C-axis assembly includes a C-axis housing, a C-axis servo motor, a C-axis drive pulley, a C-axis synchronous belt, a C-axis driven pulley, and a C-axis reducer. The C-axis housing is rigidly connected to the spindle box of the XYZ gantry via a flange. The fixed ends of the C-axis servo motor and the C-axis reducer are both fixed to the C-axis housing. The output end of the C-axis servo motor is connected to the C-axis drive pulley, which is then connected to the C-axis driven pulley via the C-axis synchronous belt. The C-axis driven pulley is fixedly connected to the input end of the C-axis reducer, and the output end of the C-axis reducer is rigidly connected to the B-axis housing of the B-axis assembly. The B-axis assembly includes a B-axis housing, a B-axis servo motor, a B-axis drive pulley, a B-axis synchronous belt, a B-axis driven pulley, a B-axis reducer, a B-axis encoder, a reducer side support plate, and a swing arm. The fixed ends of the B-axis servo motor and the B-axis reducer are fixed to the B-axis housing. The output end of the B-axis servo motor is connected to the B-axis drive wheel, which is connected to the B-axis driven wheel via the B-axis synchronous belt. The B-axis driven wheel is fixed to the input end of the B-axis reducer. The output end of the B-axis reducer is fixedly connected to the reducer side support plate. The reducer side support plate is fixedly connected to the swing arm. The electric spindle is fixed on the swing arm.

2. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The C-axis assembly also includes a C-axis encoder. The C-axis encoder stator is fixed to the C-axis housing via a C-axis encoder bracket, and the C-axis encoder rotor is coaxially fixed to the C-axis driven wheel.

3. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The C-axis assembly also includes a C-axis pneumatic brake disc, which is mounted between the output end of the C-axis reducer and the B-axis housing.

4. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The B-axis assembly also includes a B-axis encoder. The rotor of the B-axis encoder is fixed on a second encoder bracket, which is mounted on a swing arm and rotates with it. The stator of the B-axis encoder is mounted on a first encoder bracket, which is installed together with a support sleeve and fixed to the B-axis housing.

5. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The B-axis assembly also includes a B-axis pneumatic brake disc, which is mounted between the output end of the B-axis reducer and the side support plate of the reducer.

6. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The integrated wiring and conduits within the B-axis housing and C-axis housing are routed centrally via dedicated conduits.

7. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The second encoder bracket rotates with the swing arm, while the first encoder bracket is fixed on the support sleeve of the B-axis housing.

8. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The C-axis encoder bracket is fixed inside the C-axis housing, and the rotor of the C-axis encoder rotates with the C-axis driven wheel.

9. The five-axis oscillating head for aluminum alloy machining as described in claim 1, characterized in that, The electric spindle is used to mount cutting tools and, in conjunction with the B-axis, C-axis, and XYZ three-axis gantry feed, enables five-axis machining of aluminum alloys.

10. A five-axis oscillating head working method for aluminum alloy machining, characterized in that, The five-axis oscillating head for aluminum alloy machining according to any one of claims 1-9 includes the following process: The C-axis housing is rigidly fixed to the gantry spindle box, and linear feed is achieved along the XYZ axes of the gantry. The C-axis servo motor starts, driving the C-axis drive wheel, which transmits the power through the C-axis synchronous belt and C-axis driven wheel to the C-axis reducer, causing the B-axis housing and the B-axis assembly and electric spindle mounted on it to rotate around the C-axis. The C-axis encoder provides real-time feedback of the rotation angle and corrects position deviations based on the feedback signal. The B-axis servo motor starts, driving the B-axis drive wheel, which transmits the power through the B-axis synchronous belt and B-axis driven wheel to the B-axis reducer, causing the B-axis swing arm and electric spindle to swing around the B-axis. The B-axis encoder provides real-time feedback of the swing angle, and corrects position deviations based on the feedback signal. After the positional deviation of the C-axis assembly and the B-axis assembly is adjusted to the correct position, the C-axis pneumatic brake disc and the B-axis pneumatic brake disc are respectively tightened to a fixed angle. The electric spindle starts and, in conjunction with the linear feed of the XYZ axes of the gantry, completes the five-axis linkage machining of the aluminum alloy workpiece.

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