Ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center

Abstract

The application discloses a kind of ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center, it is related to composite machining center technical field;The machining center includes machine tool bed, five-axis linkage movement mechanism, low-pressure micro-arc machining electric spindle, low-pressure micro-arc anode upper electrical device, automatic tool changer, composite machining tool handle, low-pressure micro-arc multifunctional power supply, working fluid circulation system and numerical control system;The application will mechanical cutting, low-pressure micro-arc discharge machining, electrolytic machining, ultrasonic vibration auxiliary four processing modes be integrated in same five-axis linkage platform, workpiece once clamping can complete rough machining, finishing, special composite machining etc. multiple processes, eliminate the positioning error caused by multiple clamping;Rely on the cavitation effect of ultrasonic vibration to improve machining gap chip removal effect and break workpiece surface passivation film, can realize the high efficiency, high precision, high surface integrity machining of difficult-to-machine material complex curved surface parts, reduce processing cost, shorten manufacturing cycle.

Description

Technical Field

[0001] This invention belongs to the technical field of composite machining centers, specifically relating to an ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center. Background Technology

[0002] In recent years, the performance requirements of high-end equipment in fields such as aerospace, defense, medical devices and chemicals have been continuously increasing, which has driven the continuous expansion of the application scope of difficult-to-machine materials such as nickel-based high-temperature alloys, titanium alloys and silicon carbide ceramic matrix composites. These materials generally have typical characteristics such as high hardness, high toughness, high temperature resistance and corrosion resistance, which bring severe challenges to the processing technology.

[0003] Traditional machining, as the main method for removing large amounts of metal materials, exposes a series of prominent problems when machining the aforementioned difficult-to-machine materials: rapid tool wear, excessively high temperature in the cutting zone, severe work hardening, significant residual stress, and difficulty in ensuring surface integrity. These problems lead to low machining efficiency, high cost, and in severe cases, even the inability to meet the requirements of precision forming.

[0004] Low-pressure micro-arc machining achieves stable microscale arc discharge by reducing the discharge voltage, significantly reducing heat input density and effectively suppressing ablation and microcrack propagation on the material surface. This technology utilizes high-temperature plasma generated by high-energy arc discharge to achieve thermal erosion of materials, combining the advantages of high efficiency, low cost, and low energy consumption. It has become an effective means of efficiently removing large allowances from difficult-to-machine materials. However, this technology is still constrained by bottlenecks such as the retention of erosion products, instability of the discharge gap, and heat accumulation, and the machining accuracy and surface quality need to be further improved.

[0005] Electrolytic machining removes materials using the principle of electrochemical anodic dissolution. It has advantages such as no tool wear, no heat-affected layer, and good surface quality, making it suitable for precision machining. However, its material removal efficiency is relatively low, and its stability is poor when machining easily passivated materials (such as titanium alloys and high-temperature alloys), often requiring auxiliary means to break the passivation film.

[0006] Ultrasonic vibration machining can effectively improve the medium circulation state of the machining interface through high-frequency micro-impact and cavitation effect, assist in the removal of passivation film and electro-erosion products, and inhibit the propagation of surface micro-cracks. It is particularly suitable for forming and machining hard and brittle materials. However, when used alone, the material removal efficiency is limited and it is difficult to meet the needs of large-mass machining.

[0007] Therefore, it is evident that the deep integration of three energy fields—low-pressure micro-arc high-efficiency erosion, electrolytic high-quality forming, and ultrasonic vibration-assisted control—is expected to achieve high-efficiency, high-precision, and high-surface-integrity machining of complex parts made of difficult-to-machine materials. However, there is currently no mature solution that organically integrates the above three energy fields into the same five-axis machine tool. Existing special machining tools often only have single or dual energy field machining capabilities, while general-purpose five-axis machining centers cannot directly perform electrochemical or electrical discharge machining. As a result, complex curved surface parts such as integral impellers and turbine blades often need to be clamped multiple times between multiple machines, which seriously affects machining accuracy and efficiency.

[0008] Therefore, developing a novel composite machining center that integrates three energy fields—ultrasonic vibration, low-voltage micro-arc discharge, and electrolytic machining—and possesses five-axis linkage capability has significant engineering application value and theoretical research significance. Summary of the Invention

[0009] The purpose of this invention is to provide an ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: an ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center, comprising a machine tool bed, a five-axis linkage motion mechanism disposed on the machine tool bed, a low-pressure micro-arc machining electric spindle mounted on the lower end of the Z-axis feed mechanism of the five-axis linkage motion mechanism, a low-pressure micro-arc anode power supply device disposed around the outside of the low-pressure micro-arc machining electric spindle, an automatic tool changer, a composite machining tool holder mechanism detachably assembled on the lower end of the low-pressure micro-arc machining electric spindle, a low-pressure micro-arc multifunctional power supply, a working fluid circulation system, and a CNC system; The CNC system is electrically connected to the five-axis linkage motion mechanism, the automatic tool changer, the low-voltage micro-arc multi-functional power supply, the working fluid circulation system, and the composite machining tool holder mechanism to achieve linkage control. The low-voltage micro-arc multifunctional power supply is electrically connected to the electrode at the bottom of the composite machining tool holder mechanism and the workpiece on the C-axis rotary table of the five-axis linkage motion mechanism, forming a machining power supply circuit.

[0011] In one preferred embodiment, the five-axis linkage motion mechanism includes an X-axis feed mechanism, a Y-axis feed mechanism, a Z-axis feed mechanism, and an A / C-axis cradle-type double rotary table; The X-axis feed mechanism includes an X-axis servo drive motor, an X-axis bed casting, an X-axis moving slide, an X-axis linear guide, an X-axis ball screw, and an X-axis U-shaped telescopic bellows protective cover. The Y-axis feed mechanism includes a Y-axis servo drive motor, a Y-axis bed base, a Y-axis sliding slide, a Y-axis linear guide, a Y-axis ball screw, and a Y-axis telescopic protective cover; The Z-axis feed mechanism includes a Z-axis servo motor, a Z-axis fixed column, a Z-axis ball screw, and a Z-axis U-shaped telescopic bellows cover. The A / C axis cradle-type double rotary worktable includes an A / C axis servo motor, a cradle fixed base, a cradle swing frame, an A-axis rotary bearing assembly, a C-axis rotary worktable, and a cradle U-shaped telescopic bellows protective cover; Each linear axis is fed linearly by a corresponding servo motor in conjunction with a ball screw and linear guide. Each protective cover extends and retracts synchronously with the corresponding moving parts to achieve dust and chip protection. The A / C axis is driven by an A / C axis servo motor to realize the workpiece's swing and rotation motion.

[0012] In one preferred embodiment, the automatic tool changer includes a robotic arm rotary motor, a robotic arm telescopic tool-drawing motor, a chain rotation drive motor, a tool magazine fixing frame, a roller chain, a tool sleeve, a robotic arm, and a tool changing port; The tool magazine fixing frame is fixed to the side wall of the Z-axis fixing column. Three motors drive the roller chain to index and cycle, the robot arm to rotate and reposition, and the telescopic tool pulling action. Multiple sets of tool sleeves for loading tools or electrodes are arranged in an array on the roller chain.

[0013] In a preferred embodiment, the working fluid circulation system includes a circulation pump body, a multi-stage filtration assembly, a liquid storage tank, a pipeline delivery assembly, and a liquid collection tank; The liquid storage tank is installed at the bottom of the Y-axis bed base, the liquid collection tank is located at the bottom of the cradle fixed base and arranged around the C-axis rotating worktable, the pipeline conveying assembly connects the liquid storage tank and the spindle machining station, the machining waste liquid flows into the multi-stage filtration assembly through the liquid collection tank and then flows back to the liquid storage tank after filtration, forming a closed loop.

[0014] In one preferred embodiment, the low-pressure micro-arc anode power supply device includes a brush, a brush holder, a cylindrical helical compression spring, and a copper tube; The copper tube is fixedly fitted onto the outer wall of the low-pressure micro-arc machining electric spindle. A cylindrical helical compression spring is installed on the brush holder and pushes the brush, so that the brush is continuously in contact with the outer wall of the copper tube, achieving continuous conductivity during spindle rotation.

[0015] In a preferred embodiment, the composite machining tool holder mechanism integrates a composite machining tool holder, an ultrasonic vibration device, and a wireless power-on device; The wireless power-on device receives electrical energy in a non-contact manner and supplies power to the ultrasonic vibration device. The ultrasonic vibration device is connected to the electrodes at the bottom and transmits high-frequency vibrations to the electrodes. The composite machining tool holder mechanism is fully insulated throughout its entire path, and its outer surface is coated with an electrolyte-resistant anti-corrosion coating.

[0016] In a preferred embodiment, the housing of the low-voltage micro-arc multifunctional power supply is provided with an operation panel, a running indicator light, and an emergency stop indicator light, and a cooling fan is provided inside the housing of the low-voltage micro-arc multifunctional power supply. The power output terminal of the low-voltage micro-arc multifunctional power supply is provided with a low-voltage micro-arc power supply positive terminal and a low-voltage micro-arc power supply negative terminal. The low-voltage micro-arc power supply positive terminal is electrically connected to the low-voltage micro-arc machining electric spindle, and the low-voltage micro-arc power supply negative terminal is electrically connected to the C-axis rotary table. The low-voltage micro-arc multifunctional power supply has the function of real-time voltage and current acquisition of the processing circuit, and feeds back the acquired working condition data to the CNC system.

[0017] In a preferred embodiment, the Z-axis feed mechanism further includes a nitrogen balance cylinder assembly, which is installed at the top center of the Z-axis fixed column. The cylinder is filled with nitrogen at a constant pressure to counteract the weight of the ram and the low-pressure micro-arc machining electric spindle, thereby reducing the axial load on the Z-axis ball screw.

[0018] As a preferred embodiment, the CNC system has multiple built-in process control programs, which can switch between four operating modes: mechanical cutting, low-voltage micro-arc discharge, electrolytic machining, and ultrasonic composite machining. It can also dynamically adjust the feed speed and discharge machining parameters of each axis based on the voltage and current data fed back by the low-voltage micro-arc multifunctional power supply.

[0019] In one preferred embodiment, the multi-stage filtration assembly includes a multi-stage gradient filter media structure, which can filter out iron filings, electrolytically precipitated impurities and fine molten particles from the processing waste liquid in stages, thereby realizing the closed-loop recycling and reuse of the working fluid.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention integrates four processing methods—mechanical cutting, low-pressure micro-arc discharge machining, electrolytic machining, and ultrasonic vibration—into a single five-axis machining center. The workpiece can complete multiple processes, including roughing, finishing, and special composite machining, in a single clamping operation. This eliminates the need for multiple disassembly and reassembly of the workpiece for alignment, effectively eliminating positioning errors caused by multiple clamping operations and significantly improving the machining accuracy and production efficiency of complex curved surface parts.

[0021] 2. Relying on the ultrasonic vibration assistance integrated into the composite machining tool holder mechanism, the cavitation effect is used to break the passivation film on the workpiece surface and remove the electro-erosion products in the machining gap in a timely manner during the machining process; coupled with non-contact wireless power transmission to continuously power the ultrasonic components, the interference of lead wire entanglement with spindle rotation is avoided. This not only improves the defects of easy passivation and low removal efficiency in electrolytic machining, but also alleviates the problems of residue retention, unstable gap, heat-affected zone and recast layer in low-pressure micro-arc machining, and simultaneously optimizes the machining stability and surface quality of the finished product of the two special machining processes.

[0022] 3. Each moving axis of the equipment is equipped with a telescopic protective cover, which can extend and retract synchronously with the corresponding component, fully covering the precision transmission components such as guide rails and lead screws, effectively preventing the intrusion of machining chips, working fluid and electrolyte, ensuring transmission accuracy and extending the service life of the equipment.

[0023] 4. The equipment is equipped with an independent closed-loop working fluid circulation system, which, together with multi-stage filtration components, removes iron filings, electrolytically precipitated impurities, and fine molten particles. The working fluid can be repeatedly recycled, reducing consumable consumption and balancing economic efficiency with environmental protection requirements.

[0024] 5. The low-voltage micro-arc anode power supply device uses a spring to press the brush structure, which can still maintain stable conductivity under the high-speed rotation of the low-voltage micro-arc machining electric spindle, solving the problem of continuous power supply to the rotating spindle; after the brush wears, it can be automatically compensated by the spring, extending the maintenance cycle.

[0025] 6. The low-voltage micro-arc multi-functional power supply can collect the voltage and current data of the processing circuit in real time and upload them to the CNC system. The CNC system dynamically adjusts the feed speed and discharge parameters according to the working parameters, effectively avoiding faults such as short circuits and abnormal arcing, and improving the safety of equipment operation.

[0026] 7. Equipped with an automated chain tool changer, it can quickly switch cutting tools, micro-arc electrodes, and electrolytic electrodes according to process requirements. Combined with five-axis linkage, it can flexibly adjust the workpiece machining posture and adapt to the diverse machining needs of various difficult-to-machine complex components such as titanium alloys and high-temperature alloys.

[0027] 8. The Z-axis is equipped with a nitrogen balance cylinder structure, which effectively counteracts the weight of the spindle and slide, reduces the axial load on the lead screw, improves the smoothness and positioning accuracy of the Z-axis feed motion, and extends the service life of the transmission components. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention; Figure 2 This is a schematic diagram of the feed transmission device for the XZ axis of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention. Figure 3 This is a schematic diagram of the feed transmission device for the Y-axis of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention; Figure 4 This is a schematic diagram of the AC cradle rotation device of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention; Figure 5 This is a schematic diagram of the automatic tool changer structure of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention; Figure 6This is a schematic diagram of the working fluid circulation system of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention; Figure 7 This is a schematic diagram of the low-voltage micro-arc anode power supply device in this invention; Figure 8 This is a front view of the low-voltage micro-arc multifunctional power supply for the ultrasonic vibration composite low-voltage micro-arc electrolysis five-axis machining center of the present invention; Figure 9 This is a schematic diagram of the back of the low-voltage micro-arc multifunctional power supply of the ultrasonic vibration composite low-voltage micro-arc electrolysis five-axis machining center of the present invention; Figure 10 This is a schematic diagram of the composite machining tool holder structure of the ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center of the present invention.

[0029] In the diagram: 1. Machine tool bed; 2. CNC system; 3. Low-voltage micro-arc multi-functional power supply; 4. Composite machining tool holder mechanism; 111. Z-axis U-shaped telescopic bellows protective cover; 112. Z-axis servo motor; 113. Nitrogen balance cylinder assembly; 114. Z-axis ball screw; 115. Z-axis fixed column; 121. X-axis servo drive motor; 122. X-axis bed casting; 123. X-axis moving slide; 124. X-axis linear guide; 125. X-axis ball screw; 126. X-axis U-shaped telescopic bellows protective cover; 131. Y-axis servo drive motor; 132. Y-axis bed base; 133. Y-axis sliding slide; 134. Y-axis linear guide; 135. Y-axis ball screw; 136. Y-axis telescopic protective cover; 141. A / C axis servo motor; 142. Cradle mounting base; 143. Cradle swing frame; 144. A-axis rotary bearing assembly; 145. C-axis rotary table; 146. Cradle U-shaped telescopic bellows protective cover; 151. Robotic arm rotary motor; 152. Robotic arm telescopic blade-drawing motor; 153. Chain rotary drive motor; 154. Tool magazine fixing frame; 155. Roller chain; 156. Tool sleeve; 157. Robotic arm; 158. Tool changer; 161. Circulating pump body; 162. Multi-stage filter assembly; 163. Liquid storage tank; 164. Piping delivery assembly; 165. Liquid collection tank; 171. Low-pressure micro-arc machining electric spindle; 172. Copper tube; 173. Brush; 174. Brush holder; 175. Cylindrical helical compression spring; 31. Operation indicator light; 32. Emergency stop indicator light; 33. Cooling fan; 34. Control panel; 35. Positive terminal of low-voltage micro-arc power supply; 36. Negative terminal of low-voltage micro-arc power supply; 42. Wireless power-on device; 43. Electrode; 44. Ultrasonic vibration device; 45. Composite machining tool holder. Detailed Implementation

[0030] The present invention will be further described below with reference to embodiments.

[0031] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0032] Please see Figure 1 This machining center consists of four main parts: machine tool bed 1, CNC system 2, low-voltage micro-arc multi-functional power supply 3, and composite machining tool holder mechanism 4.

[0033] The machine tool bed 1 serves as the mounting base for the entire machine. It is an integrated assembly of the X / Y / Z three-axis feed mechanism, AC cradle rotation mechanism, automatic tool changer, and working fluid circulation system. It supports all moving parts and machining execution parts, realizing five-axis linkage feed and automatic tool changing.

[0034] The CNC system 2 is installed on the side of the machine tool and is electrically connected to the servo motors of each axis, the tool change drive motor, the circulating pump 161, the low-voltage micro-arc multi-functional power supply 3, and the ultrasonic vibration device 44. It uniformly controls the machine's feed trajectory, tool change sequence, working fluid start / stop, and special machining parameter switching. The low-voltage micro-arc multi-functional power supply 3 is independently arranged on the side of the machine tool and is connected to the electrodes 43 of the four composite machining tool holder mechanisms and the C-axis rotary table 145 through wires to form the power supply circuit required for low-voltage micro-arc and electrolytic machining. It collects machining voltage and current signals in real time and feeds them back to the CNC system 2.

[0035] The composite machining tool holder mechanism 4 is detachably clamped at the lower end of the low-pressure micro-arc machining electric spindle 171. With the composite machining tool holder 45 as the mounting base, it has a built-in ultrasonic vibration device 44 and a wireless power supply device 42. It can quickly change mechanical tools, micro-arc electrodes, and electrolytic electrodes 43 with the help of an automatic tool changer, so as to realize the composite operation of multiple machining energy fields such as ultrasonic assistance, low-pressure micro-arc discharge, electrolysis, and mechanical cutting.

[0036] Please see Figure 2 The XZ axis feed transmission device includes an X-axis feed assembly and a Z-axis column slide assembly. The Z-axis column slide assembly is fixedly installed on the sliding end face of the X-axis feed assembly. The X-axis feed assembly is used to realize the transverse X-axis feed of the workpiece, and the Z-axis column slide assembly is used to assemble the spindle components and drive the tool to realize the vertical Z-axis depth feed.

[0037] The X-axis feed assembly includes an X-axis servo drive motor 121, an X-axis bed casting 122, an X-axis moving slide 123, an X-axis linear guide 124, an X-axis ball screw 125, and an X-axis U-shaped telescopic bellows cover 126.

[0038] The X-axis bed casting 122 serves as the fixed mounting base for the entire X-axis. The top surface of the casting is precision machined with two equal-height reference surfaces for parallel arrangement of the X-axis linear guide rails 124. The side wall of the casting is reserved with hoisting screw holes and mounting holes for the machine's feet.

[0039] The X-axis linear guide 124 is fixed to the top reference surface of the X-axis bed casting 122 by locking bolts. Multiple sets of ball sliders are mounted on the guide rail. The upper end of the slider is locked and fixed to the lower end surface of the X-axis moving slide 123 to constrain the X-axis moving slide 123 to slide horizontally only in the X direction.

[0040] The X-axis moving slide 123 is mounted on the slider of the X-axis linear guide 124. The tail of the slide is integrally cast with a nut receiving cavity. The cavity is press-fitted with the double-nut preloaded ball nut matching the X-axis ball screw 125. The ball nut is locked by the end face to prevent axial movement of the round nut.

[0041] The X-axis ball screw 125 is arranged laterally in the middle of the two X-axis linear guides 124. The entire screw is covered and shielded by the X-axis U-shaped telescopic bellows cover 126. The right end of the screw is connected to the output shaft of the X-axis servo drive motor 121 via a bellows coupling.

[0042] The X-axis servo drive motor 121 is fixed to the right end mounting bracket of the X-axis bed casting 122 by flange fastening bolts. As the X-axis feed power source, it can drive the X-axis ball screw 125 to rotate synchronously.

[0043] The X-axis U-shaped telescopic bellows cover 126 is fixed at one end to the end face of the X-axis bed casting 122, and the other end is locked to the side wall of the X-axis moving slide 123. It can extend and retract synchronously with the slide, covering the X-axis linear guide 124 and the X-axis ball screw 125, and playing a protective role against dust and chips.

[0044] The Z-axis column slide assembly includes a Z-axis U-shaped telescopic bellows protective cover 111, a Z-axis servo motor 112, a nitrogen balance cylinder assembly 113, a Z-axis ball screw 114, and a Z-axis fixed column 115.

[0045] The Z-axis fixed column 115 is a frame-type cast iron base. The bottom flange of the column is fastened to the upper end face of the X-axis moving slide 123. The vertical guide rail mounting reference surface is symmetrically machined on the inner side of the column. The top flange of the column is used to assemble the Z-axis servo motor 112 and the nitrogen balance cylinder assembly 113.

[0046] The nitrogen balance cylinder assembly 113 is installed at the top center of the Z-axis fixed column 115; the cylinder is filled with nitrogen at a constant pressure, which can continuously offset the weight of the slide and the lower low-pressure micro-arc machining electric spindle 171 assembly, and reduce the axial load of the Z-axis ball screw 114.

[0047] The Z-axis servo motor 112 is mounted on the top flange of the column next to the nitrogen balance cylinder assembly 113. The motor output shaft is connected to the upper end of the Z-axis ball screw 114 via a coupling, serving as the power input component for the Z-axis lifting action.

[0048] The Z-axis ball screw 114 is vertically housed within the central cavity of the Z-axis fixed column 115 and the inner slide. The upper end of the screw is connected to the Z-axis servo motor 112. When the Z-axis servo motor 112 drives the screw to rotate in place, the ball nut moves vertically along the screw axis, causing the slide and the low-pressure micro-arc machining electric spindle 171 at the bottom to move up and down synchronously for feeding.

[0049] The Z-axis U-shaped telescopic bellows protective cover 111 is fixed at the top of the Z-axis fixed column 115, covering the upper end of the column, the Z-axis servo motor 112 and the outside of the nitrogen balance cylinder assembly 113, and providing dust protection for the upper Z-axis components.

[0050] Please see Figure 3 The Y-axis feed transmission device is mounted on the bottom reference end of the equipment to achieve precise forward and backward Y-axis feed of the entire machine. The Y-axis feed transmission device includes a Y-axis servo drive motor 131, a Y-axis bed base 132, a Y-axis sliding slide 133, a Y-axis linear guide rail 134, a Y-axis ball screw 135, and a Y-axis telescopic protective cover 136.

[0051] The Y-axis bed base 132 is the overall mounting reference component for the Y-axis. Two sets of parallel and equal-height reference surfaces are precision machined on the top surface of the base for arranging the Y-axis linear guide rail 134. The end face of the base is reserved with motor mounting base and protective assembly screw holes.

[0052] The Y-axis linear guide 134 is fixed to the top reference surface of the Y-axis bed base 132 by locking bolts. Multiple sets of precision ball sliders are matched and installed above the guide rail. The upper end of the slider is locked and fixed to the bottom surface of the Y-axis sliding slide 133 to constrain the Y-axis sliding slide 133 to slide linearly forward and backward along the Y direction, so as to ensure the accuracy of the feed motion.

[0053] The Y-axis sliding slide 133 is slidably mounted above the slider of the Y-axis linear guide 134. A screw nut mounting cavity is integrated in the middle of the slide, and the preloaded ball nut matching the Y-axis ball screw 135 is locked and fixed inside the cavity.

[0054] The Y-axis ball screw 135 is arranged horizontally and longitudinally in the center of the two sets of Y-axis linear guides 134. The screw lever body is fully covered and protected by the Y-axis telescopic protective cover 136. One end of the screw is connected to the output shaft of the Y-axis servo drive motor 131 through a coupling. Both ends of the screw are equipped with support bearings and locking limit structures, so that the screw can only rotate on a fixed axis without axial movement error. The screw lever body is inserted through the ball nut of the Y-axis sliding slide plate 133.

[0055] The Y-axis servo drive motor 131 is fixed to the mounting base at the end of the Y-axis bed base 132 by flange bolts. As the Y-axis feed power source, it can precisely drive the Y-axis ball screw 135 to rotate and provide power output for Y-axis feed.

[0056] The Y-axis telescopic protective cover 136 is fixed at both ends to the Y-axis bed base 132 and the Y-axis sliding slide 133 end face, respectively. It can move back and forth synchronously with the Y-axis sliding slide 133, completely covering the Y-axis linear guide 134 and the Y-axis ball screw 135, effectively isolating machining chips and cutting fluid, and protecting the stable operation of the Y-axis transmission structure.

[0057] Please see Figure 4 The AC cradle rotary device is used to realize the swing and rotation motion of the workpiece, and completes five-axis linkage machining in conjunction with three-axis feed. The AC cradle rotary device includes A / C axis servo motors 141, cradle fixed base 142, cradle swing frame 143, A-axis rotary bearing assembly 144, C-axis rotary worktable 145, and cradle U-shaped telescopic bellows protective cover 146.

[0058] The cradle fixing base 142 serves as the installation reference for the AC cradle rotation device. Symmetrical A-axis rotation mounting positions are arranged on both sides of the base, providing a stable support reference for the overall cradle structure. The A / C axis servo motors 141 are fixedly installed on the outer end face of the cradle fixing base 142, including an A-axis swing servo motor and a C-axis rotation servo motor, which provide independent power output for cradle swing and table rotation, respectively, with fast response speed and high positioning accuracy.

[0059] The cradle swing frame 143 is rotatably mounted on the inner side of the cradle fixed base 142 via the A-axis rotary bearing assembly 144. The A-axis rotary bearing assembly 144 ensures that the cradle swing frame 143 can swing at an angle along the A-axis, while bearing the processing load, ensuring the stability and coaxiality of the swing motion.

[0060] The C-axis rotary table 145 is rotatably mounted on the inner side of the middle of the cradle swing frame 143, and can independently complete a 360° rotation. It is used to clamp and fix the workpiece. While swinging synchronously with the cradle swing frame 143, it rotates autonomously to realize multi-angle posture adjustment of the workpiece.

[0061] The U-shaped telescopic bellows protective cover 146 of the cradle covers the outside of the cradle fixed base 142 and the cradle swing frame 143, and shields and protects the internal A-axis rotary bearing assembly 144, transmission structure and motor connection parts to prevent the intrusion of machining chips and cutting fluid, and ensure the long-term stable operation of the AC cradle rotary mechanism.

[0062] Please refer to Figure 5 The automatic tool changer is a chain-type robotic arm tool changing structure, corresponding to the spindle station, used to realize automated switching of machining tools and improve the continuity of equipment processing. The automatic tool changer includes a robotic arm rotary motor 151, a robotic arm telescopic tool-drawing motor 152, a chain rotation drive motor 153, a tool magazine fixing frame 154, a roller chain 155, a tool holder 156, a robotic arm 157, and a tool changing port 158.

[0063] The tool magazine mounting frame 154 is fixed to the side wall of the Z-axis mounting column 115 with high-strength bolts, providing a stable mounting support benchmark for all components of the tool changing device, and the overall structure is rigid and stable. The robot arm rotary motor 151 is installed at the robot arm mounting end of the tool magazine mounting frame 154, providing power for the robot arm's rotation, and can drive the robot arm 157 to precisely rotate and switch positions, realizing the interchange and docking of the tool magazine pick-up position and the spindle tool changing position.

[0064] The telescopic tool-drawing motor 152 is mounted inside the rotating base of the robot arm, providing power for the robot arm's telescopic, tool-drawing, and resetting actions. It drives the robot arm 157 to complete the telescopic displacement, realizing the clamping, pulling out, and assembly of tools. The chain rotation drive motor 153 is fixed to the end of the tool magazine fixing frame 154, providing power for the rotation of the chain-type tool magazine. It can drive the roller chain 155 to rotate cyclically, driving the tool sleeve 156 on the chain to index and switch, completing the precise selection and delivery of the target tool.

[0065] A roller chain 155 is cyclically assembled inside the tool magazine fixing frame 154, with multiple sets of tool sleeves 156 evenly arrayed on the chain to achieve multiple tool storage and rotation. A robotic arm 157 is rotatably mounted at the front end of the tool magazine fixing frame 154, and is matched with two robotic arm drive motors, capable of synchronously completing rotation and extension movements. Its end-gripping structure can stably grasp tools, completing core tool changing actions such as tool retrieval, tool loading, and tool retraction. The tool changing port 158 ​​is located at the tool changing reference position of the tool magazine fixing frame 154, and is a high-precision positioning structure used to define the tool changing position.

[0066] Please see Figure 6 The working fluid circulation filtration system is installed at the bottom of the Y-axis bed base 132 and the rear area of ​​the equipment, and is connected to the machining station of the central AC cradle rotary device. The working fluid circulation filtration system includes a circulation pump body 161, a multi-stage filtration assembly 162, a liquid storage tank 163, a pipeline delivery assembly 164, and a liquid collection tank 165.

[0067] The liquid storage tank 163 is the system's liquid storage reference component. It is fixedly installed in the empty area at the bottom of the Y-axis bed base 132 and is completely sealed. It is used to store the working fluid, electrolyte and cutting fluid required for machining, providing a stable liquid source for the entire circulation system, while avoiding interference from the moving parts of the machine tool.

[0068] The circulating pump body 161 is fixedly mounted on the outer end face of the liquid storage tank 163. As the power component for the circulation of working fluid, it can draw liquid from inside the liquid storage tank 163 and pressurize and transport it to the processing station through the pipeline delivery assembly 164. At the same time, it provides power support for the waste liquid return circulation, ensuring continuous liquid circulation. The multi-stage filter assembly 162 is integrated and installed at the return port of the liquid storage tank 163. It contains multi-stage gradient filter media and can filter out iron filings, electrolytically precipitated impurities, and fine molten particles in stages.

[0069] The pipeline delivery assembly 164 is installed on the side wall and internal empty area of ​​the machine tool. One end is connected to the circulating pump body 161, and the other end extends to the spindle machining station and the AC cradle rotary device station. It can accurately deliver the purified working fluid to the machining area to achieve the functional requirements of cooling, lubrication, electrolytic fluid supply, and discharge chip removal.

[0070] The liquid collection tank 165 is formed on the bottom of the outer periphery of the cradle fixing base 142, corresponding to the processing area of ​​the C-axis rotary worktable 145. It is used to collect waste liquid and waste chips mixed with various impurities after processing. After being collected and summarized, the waste liquid is transported to the multi-stage filtration component 162 through the return pipeline. After filtration and purification, the waste liquid is returned to the liquid storage tank 163 to achieve closed-loop recycling.

[0071] Please see Figure 7 The low-pressure micro-arc anode power supply device is installed inside the Z-axis fixed column 115 and is arranged around the low-pressure micro-arc machining electric spindle 171. Six brushes 173 are arranged in a row and placed in two rows on the brush holder 174. The ends of the brushes are equipped with cylindrical helical compression springs 175. After long-term operation, the brushes 173 wear down and become shorter. The cylindrical helical compression springs 175 generate thrust, pushing the brushes close to the copper tube 172 of the low-pressure micro-arc machining electric spindle 171 for continuous power transmission.

[0072] Please see Figure 8 and Figure 9 During processing, the positive terminal 35 and negative terminal 36 of the low-voltage micro-arc power supply 3 are connected to the low-voltage micro-arc machining electric spindle 171 and the C-axis rotary table 145 respectively by wires.

[0073] The cooling fan 33 is located inside the power supply for heat dissipation and cooling; the operation indicator 31 illuminates during operation, and the emergency stop indicator 32 illuminates when the power supply stops or is in an emergency stop. The operation panel 34 allows adjustment of the voltage, duty cycle, and discharge frequency, and displays real-time voltage and current waveforms.

[0074] Please see Figure 10 The composite machining tool holder mechanism 4 uses a composite machining tool holder 45 as its main body and is equipped with an ultrasonic vibration device 44 inside. A wireless power supply device 42 is connected to the low-voltage micro-arc machining electric spindle 171 to provide power to the ultrasonic vibration device 44 and transmit the ultrasonic vibration to the electrode 43. The outer surface of the composite machining tool holder mechanism 4 is covered with an anti-corrosion and insulating coating to isolate electrolyte corrosion and leakage.

[0075] Working principle and usage process of this invention: The operator inputs the machining program and process parameters through the CNC system 2. The CNC system 2 coordinates and manages the coordinated operation of the servo mechanisms of each axis, the low-voltage micro-arc multi-functional power supply 3, the automatic tool changer, the circulating pump 161, and the ultrasonic vibration device 44.

[0076] First, based on the workpiece processing requirements, the CNC system 2 controls the automatic tool changer to replace the matching machine milling cutter, low-voltage micro-arc electrode, or electrolytic electrode 43 with the composite machining tool holder mechanism 4. During conventional mechanical cutting, the CNC system 2 shuts down the low-voltage micro-arc multi-functional power supply 3 and the ultrasonic vibration device 44, and drives the X / Y / Z / A / C five-axis linkage to complete the milling shape.

[0077] During low-pressure micro-arc machining, the CNC system 2 controls the low-pressure micro-arc multi-functional power supply 3 to output the corresponding voltage and current. The positive terminal 35 of the low-pressure micro-arc power supply is continuously connected to the electrode 43 of the low-pressure micro-arc machining electric spindle 171 and the composite machining tool holder mechanism 4 via the brush 173 pressed by the cylindrical spiral compression spring 175 of the low-pressure micro-arc anode power supply device and the copper tube 172 of the low-pressure micro-arc machining electric spindle 171. The negative terminal 36 of the low-pressure micro-arc power supply is connected to the workpiece on the C-axis rotary table 145 to form a discharge circuit.

[0078] Simultaneously, the ultrasonic vibration device 44 is activated, and the working fluid circulation system pumps special working fluid from the circulation pump body 161 to flush the processing gap. Ultrasonic cavitation is used to remove electrolytic erosion residue. Under the electrolytic finishing condition, the working fluid circulation system switches to deliver electrolyte, and the ultrasonic vibration device 44 continuously vibrates to break the passivation film on the workpiece surface, thereby improving the stability of electrolytic dissolution.

[0079] When performing ultrasonic arc electrolysis composite processing, the CNC system 2 controls the low-voltage micro-arc multifunctional power supply 3 to synchronously output arc discharge and electrolysis adaptation parameters, and the low-voltage micro-arc anode power supply device maintains a continuous conductive state. The three energy fields of ultrasonic vibration, micro-arc arc and electrolysis are synchronously coupled and work together to remove materials.

[0080] The processing waste liquid is collected in the collection tank 165, sent to the multi-stage filtration component 162 for graded impurity removal, and then returned to the storage tank 163 for recycling. Multiple processes can be continuously processed with a single workpiece clamping.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A five-axis machining center with ultrasonic vibration composite low-pressure micro-arc electrolysis, characterized in that, The system includes a machine tool bed (1), a five-axis linkage motion mechanism mounted on the machine tool bed (1), a low-pressure micro-arc machining electric spindle (171) mounted on the lower end of the Z-axis feed mechanism of the five-axis linkage motion mechanism, a low-pressure micro-arc anode power supply device arranged around the outside of the low-pressure micro-arc machining electric spindle (171), an automatic tool changer, a composite machining tool holder mechanism (4) detachably mounted on the lower end of the low-pressure micro-arc machining electric spindle (171), a low-pressure micro-arc multi-functional power supply (3), a working fluid circulation system, and a numerical control system (2). The CNC system (2) is electrically connected to the five-axis linkage motion mechanism, the automatic tool changer, the low-voltage micro-arc multi-functional power supply (3), the working fluid circulation system, and the composite machining tool holder mechanism (4) respectively, and realizes linkage control. The low-voltage micro-arc multifunctional power supply (3) is electrically connected to the electrode (43) at the bottom of the composite machining tool holder mechanism (4) and the workpiece on the C-axis rotary table (145) of the five-axis linkage motion mechanism, forming a machining power supply circuit.

2. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 1, characterized in that: The five-axis linkage motion mechanism includes an X-axis feed mechanism, a Y-axis feed mechanism, a Z-axis feed mechanism, and an A / C-axis cradle-type double rotary table; The X-axis feed mechanism includes an X-axis servo drive motor (121), an X-axis bed casting (122), an X-axis moving slide (123), an X-axis linear guide (124), an X-axis ball screw (125), and an X-axis U-shaped telescopic bellows cover (126). The Y-axis feed mechanism includes a Y-axis servo drive motor (131), a Y-axis bed base (132), a Y-axis sliding slide (133), a Y-axis linear guide (134), a Y-axis ball screw (135), and a Y-axis telescopic protective cover (136). The Z-axis feed mechanism includes a Z-axis servo motor (112), a Z-axis fixed column (115), a Z-axis ball screw (114), and a Z-axis U-shaped telescopic bellows cover (111). The A / C axis cradle-type double rotary table includes an A / C axis servo motor (141), a cradle fixed base (142), a cradle swing frame (143), an A axis rotary bearing assembly (144), a C axis rotary table (145), and a cradle U-shaped telescopic bellows protective cover (146). Each linear axis is fed linearly by a corresponding servo motor in conjunction with a ball screw and a linear guide. Each protective cover extends and retracts synchronously with the corresponding moving parts to achieve dust and chip protection. The A / C axis is driven by an A / C axis servo motor (141) to achieve the swing and rotation of the workpiece.

3. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 2, characterized in that: The automatic tool changer includes a robotic arm rotary motor (151), a robotic arm telescopic tool-drawing motor (152), a chain rotation drive motor (153), a tool magazine fixing frame (154), a roller chain (155), a tool sleeve (156), a robotic arm (157), and a tool changing port (158). The tool magazine fixing frame (154) is fixed to the side wall of the Z-axis fixing column (115). Three motors drive the roller chain (155) to index and cycle, the robot (157) to rotate and reposition, and the telescopic tool pulling action. Multiple sets of tool sleeves (156) for loading tools or electrodes are arranged in an array on the roller chain (155).

4. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 2, characterized in that: The working fluid circulation system includes a circulation pump body (161), a multi-stage filtration assembly (162), a liquid storage tank (163), a pipeline delivery assembly (164), and a liquid collection tank (165). The liquid storage tank (163) is installed at the bottom of the Y-axis bed base (132). The liquid collection tank (165) is located at the bottom of the cradle fixing base (142) and arranged around the C-axis rotating worktable (145). The pipeline conveying assembly (164) connects the liquid storage tank (163) with the spindle machining station. The machining waste liquid flows into the multi-stage filtration assembly (162) through the liquid collection tank (165) for filtration and then flows back to the liquid storage tank (163), forming a closed loop.

5. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 1, characterized in that: The low-pressure micro-arc anode power supply device includes a brush (173), a brush holder (174), a cylindrical helical compression spring (175), and a copper tube (172). The copper tube (172) is fixedly fitted on the outer wall of the low-pressure micro-arc machining electric spindle (171). The cylindrical spiral compression spring (175) is installed on the brush holder (174) and pushes the brush (173) so that the brush (173) and the outer wall of the copper tube (172) are continuously in contact, so as to achieve continuous conductivity in the spindle rotation state.

6. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 1, characterized in that: The composite machining tool holder mechanism (4) integrates a composite machining tool holder (45), an ultrasonic vibration device (44), and a wireless power-on device (42). The wireless power-on device (42) receives electrical energy in a non-contact manner and supplies power to the ultrasonic vibration device (44). The ultrasonic vibration device (44) is connected to the bottom electrode (43) and transmits high-frequency vibration to the electrode (43). The composite machining tool holder mechanism (4) is fully insulated throughout, and its outer surface is coated with an electrolyte-resistant anti-corrosion coating.

7. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 1, characterized in that: The low-voltage micro-arc multifunctional power supply (3) is provided with an operation panel (34), a running indicator (31) and an emergency stop indicator (32) on its housing, and a cooling fan (33) is provided inside the housing of the low-voltage micro-arc multifunctional power supply (3). The power output terminal of the low-voltage micro-arc multifunctional power supply (3) is provided with a low-voltage micro-arc power supply positive terminal (35) and a low-voltage micro-arc power supply negative terminal (36). The low-voltage micro-arc power supply positive terminal (35) is electrically connected to the low-voltage micro-arc machining electric spindle (171), and the low-voltage micro-arc power supply negative terminal (36) is electrically connected to the C-axis rotary table (145). The low-voltage micro-arc multifunctional power supply (3) has the function of real-time voltage and current acquisition of the processing circuit and feeds back the acquired working condition data to the CNC system (2).

8. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 2, characterized in that: The Z-axis feed mechanism also includes a nitrogen balance cylinder assembly (113), which is installed at the top center of the Z-axis fixed column (115). The cylinder is filled with nitrogen at a constant pressure to counteract the weight of the slide and the low-pressure micro-arc machining electric spindle (171) and reduce the axial load of the Z-axis ball screw (114).

9. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 1, characterized in that: The CNC system (2) has multiple built-in process control programs, which can switch between four operating modes: mechanical cutting, low-voltage micro-arc discharge, electrolytic machining, and ultrasonic composite machining. It can also dynamically adjust the feed speed and discharge machining parameters of each axis based on the voltage and current data fed back by the low-voltage micro-arc multifunctional power supply (3).

10. The ultrasonic vibration composite low-pressure micro-arc electrolysis five-axis machining center according to claim 4, characterized in that: The multi-stage filtration component (162) includes a multi-stage gradient filter material structure, which can filter out iron filings, electrolytically precipitated impurities and fine molten particles in the processing waste liquid in stages, so as to realize the closed-loop recycling and reuse of the working liquid.

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