Closed component integrated cathode in-situ continuous full-surface electrolytic machining device and method

Abstract

This invention relates to an in-situ continuous full-surface electrolytic machining apparatus and method for closed components using an integrated cathode, belonging to the field of electrolytic machining. The method is characterized by the following: the integrated cathode consists of an end-face cathode, a blade-base cathode, a blade-back cathode, a hub cathode, a blade-crown cathode, and an insulating support substrate. Each cathode is fixed to the insulating substrate, insulated from each other, and independently energized. The integrated cathode has a hollow structure, enabling internal fluid filling. The energization / de-energization of each cathode is matched with the feed direction; that is, when each cathode feeds along its own surface normal, the cathode is energized, causing electrochemical dissolution of the corresponding workpiece surface, while the other cathodes are de-energized, acting as insulating materials. Based on this, in-situ continuous full-surface electrolytic machining of closed components can be completed sequentially. This invention uses an integrated cathode, enabling in-situ continuous full-surface electrolytic machining of closed components with a single clamping, eliminating the need for multiple sets of cathodes and fixtures, thus improving machining efficiency and quality.

Description

Technical Field

[0001] This invention belongs to the field of electrolytic machining technology, and particularly relates to an in-situ continuous full-surface electrolytic machining device and method for an integrated cathode of a closed component. Background Technology

[0002] Closed-circuit components made of high-temperature alloys and titanium alloys are one of the core components of turbopumps in high-performance turbojet engines and launch vehicle engines. A closed-circuit component typically consists of three parts: the hub, the blade crown, and the blades. Thanks to its integral design with the blade crown, the closed-circuit component can significantly reduce gas flow losses between the blade tip and the blade crown, improving aerodynamic efficiency. Furthermore, because the hub, blades, and blade crown are designed as a single frame structure, the connections between the parts are reduced, making the structure more compact. This reduces the weight of the components while increasing the strength and rigidity of the impeller, significantly improving the reliability and service life of the components.

[0003] From blank to final ideal shape, closed-type components require forming four surfaces: the blade base, blade back, hub, and blade crown. Due to the presence of the blade crown, the blade channel is only open at the intake and exhaust sides. Furthermore, the twisted blades significantly reduce their openness, thus restricting tool movement during traditional cutting processes. This makes interference with the machined surface highly likely, resulting in poor machinability. Moreover, the materials used have poor machinability, making machining difficult. Currently, the main machining methods for closed-type components include CNC milling, electrical discharge machining (EDM), arc discharge machining (EDM), and electrolytic machining. CNC milling offers advantages such as high automation, short preparation time, and high machining accuracy, but it suffers from high tool wear, low machining efficiency, and easy deformation of thin-walled parts. For blades with complex twists and turns, its machinability is also poor. Electrical discharge machining (EDM) offers advantages such as a wide range of material adaptability, high machining accuracy, and the absence of macroscopic cutting forces, enabling the machining of low surface roughness. It is particularly suitable for machining difficult-to-machine materials and thin-walled integral components. However, tool electrode wear affects repeatability, and the recast layer and microcracks generated during EDM can negatively impact the surface quality of the workpiece. Arc discharge machining (ADM) offers high efficiency and low cost, but it suffers from significant electrode wear, material ablation, and the formation of a thick heat-affected zone on the machined surface.

[0004] Electrolytic machining is a process based on the principle of electrochemical anodic dissolution to process anodic workpieces into specific shapes and sizes. It features high material removal rate, good surface quality, no tool and cathode wear, and a wide processing range. It can be used to process any conductive material and is not limited by the material's hardness, strength, toughness, or other mechanical properties. It is commonly used to process various difficult-to-cut metals such as nickel-based superalloys, titanium alloys, and intermetallic compounds. It is particularly suitable for the mass production of parts and the processing of various parts with complex three-dimensional surfaces. It has been widely used in aerospace, weaponry, and other industries, becoming one of the mainstream manufacturing methods for complex-shaped workpieces made of difficult-to-machine materials in aero-engines both domestically and internationally.

[0005] For open integral bladed disks, traditional electrochemical machining (ECM) methods generally consist of two steps: pre-machining of the blade channel and finishing of the blade profile. First, the pre-machining of the blade channel removes most of the material between adjacent blades, forming a channel and leaving a certain machining allowance on the blade blank. In the finishing of the blade profile, the forming cathode moves into the blade channel, and the feed of the forming cathode removes the allowance left in the previous step, forming the final blade profile and completing the finishing of the blade profile. If traditional ECM methods are used to process closed components, in addition to the pre-machining of the blade channel, the finishing of the blade profile requires the separate design of cathodes for the hub surface, crown surface, blade base surface, and blade back surface, along with their corresponding fixtures. Adding to this the need for cathode correction testing, the process is cumbersome and significantly reduces machining efficiency. Repeated positioning errors caused by changing cathodes and fixtures at each step greatly reduce machining accuracy. Therefore, the traditional step-by-step ECM method for integral bladed disks is insufficient to meet the requirements of mass production, necessitating the exploration of new low-cost, high-efficiency, and high-precision ECM processes.

[0006] The patent "A Non-Circular Tool Milling Device Suitable for Machining Closed Complex Curved Surfaces" (Application No. 201710739181.3, Applicant: Beijing University of Aeronautics and Astronautics Zaozhuang Beihang Machine Tool Innovation Research Institute Co., Ltd., Inventors: Chen Zhitong, Yang Jianshi, Quan Fang, Zhang Yunning, Tao Li, Shanshan Si Chuanrui, Tian Ye) employs a non-circular tool milling device for machining closed impellers, impeller rings, and casing flow channels. This device improves the machining efficiency and quality of curved surfaces and is suitable for machining curved surfaces in semi-enclosed spaces. In contrast, this patent uses electrolytic machining, eliminating tool electrode wear, enabling the machining of difficult-to-machine materials, and allowing for the machining of complex, tortuous surfaces with poor openness.

[0007] In the patent "Five-Axis Milling Machining Method for Closed Integral Bladed Disks" (application number 200910219433.5, applicant: Northwestern Polytechnical University, inventors: Yao Changfeng, Ren Junxue, Zhang Dinghua, Shi Yaoyao, Tian Rongxin, Liang Yongshou, Huang Xinchun), the processing area of ​​the closed integral bladed disk is divided, and the milling tool trajectory is obtained for the intake side processing area and the exhaust side processing area, respectively, and the closed integral bladed disk is milled. In comparison, this patent uses electrolytic machining, which has high processing efficiency and short processing cycle, and is suitable for machining complex curved surfaces of bent and twisted composite blades with insufficient openness.

[0008] The patent "Method for EDM forming of integral closed blade rings and its fixture and electrode" (application number 201811059341.0, applicant: Xi'an Xihang Group Wright Aviation Manufacturing Technology Co., Ltd., inventors: Shi Hongmin, Li Changqing, Song Xiaoqing, Peng Mingyou, Zhang Yonggang, Shi Junqiang, Feng Yong, Zheng Xiaosong) proposes a method for EDM forming of integral closed blade rings, along with its fixture and electrode. This method relies on the electrode profile to ensure the blade and airflow channel profiles, and is not limited by the complexity of the blade profile. By using a forming electrode and a matching electrode fixture, multi-axis linkage EDM forming can be achieved on an EDM forming machine. In comparison, this patent uses in-situ continuous full-surface electrolytic machining, eliminating the need to change fixtures and reposition, simplifying the process, and achieving high repeatability accuracy.

[0009] In the patent "Method for Pre-hole Extraction and Chip Removal in Electrical Discharge Machining of Closed Integral Bladed Disk" (application number 201810899563.7, applicant: Shanghai Jiao Tong University Shenzhen Research Institute, inventors: Kang Xiaoming, Zhao Wansheng, Xu Haihua), pre-holes for extraction are machined on the closed integral bladed disk blank, and then multi-axis linkage electrical discharge machining of the blade channel is used, which can effectively remove discharge erosion products and improve machining efficiency. In comparison, this patent uses electrolytic machining, which does not require pretreatment of the workpiece, and can achieve integrated rough and fine machining of closed components in one machining process.

[0010] The patent "Stacked Internal Fluid-Forming Electrode for High-Speed ​​Electrical Discharge Machining" (application number 201210026722.5, applicant: Shanghai Jiao Tong University, inventors: Zhao Wansheng, Gu Lin, Xiang Xiaoli) proposes a stacked internal fluid-forming electrode for high-speed electrical discharge machining (EDM). This electrode includes a stacked electrode assembly and an electrode connector. The stacked electrode assembly is formed by stacking and fastening multiple electrode sheets to create a formed electrode for EDM. Multiple through-grooves are provided on the surface of the electrode sheets, and multiple through-holes are constructed between the formed electrodes through stacking the electrode sheets for internal fluid filling, thus achieving pre-processing of the blade channel. In contrast, this patent adopts an integrated cathode partitioned energizing method, matching the cathode's on / off state with the feed direction. This enables localized dissolution, high machining accuracy, and no cathode loss. It allows for in-situ continuous full-surface finishing, resulting in high machining efficiency. The hollow cathode structure allows for internal fluid filling, improving flow field uniformity and machining stability.

[0011] In the patent "An Electrolytic Machining Method for an Integral Bladed Disk" (application number 201811128151.X, applicant: China Aviation Manufacturing Technology Research Institute, inventors: Huang Mingtao, Zhang Mingqi, Cheng Xiaoyuan, Fu Junying), the machining head used includes the blade basin profile and the blade back profile to complete the precision machining of the open bladed disk cascade channel and blade profile. In comparison, this patent uses an integrated cathode, which can achieve internal flushing, better flow field uniformity, and the energization state and cathode feed direction of the machining cathodes for each profile are matched, so that the entire profile of the closed component is ultimately dissolved in the normal direction, improving the machining accuracy.

[0012] In the patent "Double-sided Combined Dual-Cathode and Segmented Controlled Electrolytic Machining Method for Integral Bladed Disks" (Application No. 202210306217.X, Applicant: Nanjing University of Aeronautics and Astronautics, Inventors: Xu Zhengyang, Shen Zhenyu, Liu Jia, Zhu Dong), a double-sided combined dual-tool cathode is fed simultaneously to perform step-by-step electrolytic machining of the blade cascade channel, blade basin surface, and blade back surface of an open integral bladed disk. In contrast, this patent uses an integrated cathode with good rigidity, enabling full-surface electrolytic machining of closed bladed disks with complex tortuous surfaces. The cathode is hollow inside, allowing for internal fluid filling and ensuring flow field uniformity and machining stability.

[0013] The patent "Electrolytic Machining Device and Method for Closed-Type Screw-In Blade Cascade Channel" (application number 202310111384.3, applicant: Nanjing University of Aeronautics and Astronautics, inventors: Zhu Dong, Yang Tuo, Zuo Hang, Zhu Di) proposes an electrolytic machining device and method for a closed-type screw-in blade cascade channel. During machining, the cathode remains fixed, and the workpiece rotates and feeds along an arc-shaped trajectory along the blade axis. Electrolytic machining is performed on the extreme facet of the cathode, gradually shaping the blade cascade channel. A multi-slit structure is provided on the cathode head to ensure sufficient electrolyte supply to the machining area. In contrast, this patent uses an integrated cathode, allowing for integrated roughing and finishing machining in a single setup, improving machining efficiency. Simultaneously, each cathode is independently energized, discretizing the electric field in the machining area. Each surface machining cathode is fed normally, achieving normal and localized dissolution of the workpiece surface, improving machining accuracy while avoiding stray corrosion, effectively improving the surface quality.

[0014] The patent "Combined Electrode Machining Method for Improving the Efficiency of Electrical Discharge Machining of Turbine Disks with Blades" (application number 201410195975.4, applicant: Capital Aerospace Machinery Corporation, China Academy of Launch Vehicle Technology, inventors: Chen Jilun, Zhong Xiaohong, Zhang Kun, Ma Ning, Sun Xiujing, Zhang Wangang, Shen Yan, Zhu Pingping) proposes a combined electrode machining method to improve the efficiency of electrical discharge machining of turbine disks with blades. This method includes roughing, semi-finishing, and finishing processes. Multiple combined electrodes are used for roughing, increasing the discharge area and improving the overall efficiency of the machining process by approximately 30%. Then, the electrodes for semi-finishing and finishing are replaced, shortening electrode changeover time and improving machine tool utilization. In comparison, this patent uses an integrated cathode, which has a simple structure, reduces cathode costs, simplifies the production process, eliminates the need for multiple clamping and positioning, and effectively improves machining accuracy.

[0015] In the patent "A Multi-channel Parallel Machining Electrode for Rough Machining of Closed Integral Bladed Disks" (application number 202011389263.8, applicant: Harbin Institute of Technology, inventors: Chi Guanxin, Jia Yuchao, Wang Zhenlong, Cui Lijuan, Wang Yukui), a multi-channel parallel machining electrode composed of an electrode base and an electrode head is used to generate arc pulse discharge for rough machining of the closed component, followed by finishing using processes such as electrical discharge machining. In comparison, this patent can achieve in-situ continuous full-surface machining using a single fixture and an integrated cathode, thus improving machining efficiency.

[0016] In the patent "High-Precision Closed-Type Impeller Forming Method" (application number 201210588218.4), the closed-type integral impeller is split into upper and lower parts, which are then separately cut, manufactured, and processed. Finally, they are welded together as a whole and then precision-machined into a finished product. In contrast, this patent achieves full-surface machining of the integral component on a single blank, avoiding the defects introduced by other connection methods and improving the stability and lifespan of the workpiece.

[0017] The patent "Electrolytic Machining Device and Method for Closed Components" (application number 202211135473.3, applicant: Nanjing University of Aeronautics and Astronautics, inventors: Zhu Dong, Hou Zhenhao, Ren Mingzhu, Zhu Di) proposes an electrolytic machining device and method for closed components. This device integrates the cathode and fixture into a single unit for precision machining of the blade profile of closed components. The integrated fixture allows for coordinated movement of the fixture and cathode, enabling simultaneous machining of the internal and external flow channels and blade profiles of the closed component. Simultaneously, it creates a closed flow field in the machining area, improving the uniformity and stability of the flow field. In comparison, this patent uses an integrated cathode, enabling in-situ continuous electrolytic machining of the entire blade profile and cascade channels, avoiding step-by-step electrolysis, reducing processes, and improving machining efficiency.

[0018] In the electrochemical machining process of closed components, most current research requires two separate machining steps from the blank to the desired profile: pre-machining of the blade channel and finishing of the blade profile. Research on completing the integrated roughing and finishing electrochemical machining of closed component blanks within a single cycle is limited. This necessitates the separate design of machining cathodes and fixtures for different machining steps, requiring disassembly and assembly of fixtures on different electrochemical machining tools for individual machining. This results in low machining efficiency, excessively long machining cycles, and reduced machining accuracy. Therefore, to simplify cathode design, improve machining efficiency, shorten machining cycles, reduce clamping and positioning errors, ensure machining accuracy, reduce stray corrosion, and improve surface quality, the inventors provide a method for in-situ continuous full-profile electrochemical machining of closed components using an integrated cathode. Summary of the Invention

[0019] Purpose of the invention: The purpose of this invention is to simplify the cathode design process, improve processing efficiency, shorten the processing cycle, reduce clamping and positioning errors, and ensure processing accuracy. It proposes an in-situ continuous full-surface electrolytic machining method for an integrated closed-type cathode.

[0020] Technical Solution: A closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool, characterized in that it includes a five-sided integrated cathode, a tooling fixture, and a driving device; the five-sided integrated cathode includes an insulating fixed support with a hollow structure, an end face machining cathode is installed at its end, and the end face machining cathode has a liquid outlet; the four sides of the insulating fixed support are respectively equipped with blade basin surface machining cathode, blade back surface machining cathode, hub surface machining cathode, and blade crown surface machining cathode; the aforementioned end face machining cathode, blade basin surface machining cathode, blade back surface machining cathode, hub surface machining cathode, and blade crown surface machining cathode are individually energized and do not conduct to each other; the tooling fixture includes a cathode rod, which has a hollow structure and an internal liquid inlet channel; the upper end of the five-sided integrated cathode is fixed to the cathode rod, and the upper part of the cathode rod is fixed to a first motion shaft and connected to the liquid inlet pipe; the tooling fixture also includes, from bottom to top, a series of... The system includes a support plate, an insulating pad, a sealing chamber, and a flexible sealing cover. The insulating pad is closely attached to the upper surface of the support plate and has several backflow grooves. The positions of the backflow grooves correspond one-to-one with the positions of the blade channel. These grooves are used to accommodate the cathodes that have protruded from the end face after processing. The lower end face of the closed component blank is attached to the upper end face of the insulating pad. The sealing chamber is closely attached to the upper end face of the closed component blank and is used to accommodate the five-sided integrated cathode to ensure that it does not interfere with its vertical movement. The flexible sealing cover is located above the sealing chamber. The driving device includes a first motion shaft, a second motion shaft, and a first rotation shaft. The first motion shaft is fixed to the second motion shaft and moves with it. The direction of movement of the first motion shaft is perpendicular to the direction of movement of the second motion shaft. The upper end face of the first rotation shaft is connected to and attached to the support plate, which can drive the closed component blank to rotate. Its axis is parallel to the direction of movement of the first motion shaft.

[0021] The aforementioned method for in-situ continuous full-surface electrolytic machining of closed-type components with integrated cathode is characterized by:

[0022] Step 1: Install the support plate, insulating pad, and closed component blank. Fix the five-sided integrated cathode to the cathode rod. Install the five-sided integrated cathode, sealing chamber, and flexible sealing cover. Use a dial indicator to measure and position the fixture, closed component blank, and integrated cathode. Install the wires and complete the tool setting. Turn on the electrolyte circulation system and exhaust system, and turn on the electrolytic machining power supply.

[0023] Step 2: Drive the five-sided integrated cathode to the optimal feed position for blade channel machining. The zoned energizing and reversing feed matching system automatically energizes the end face machining cathode. Then, drive the first motion axis to feed the five-sided integrated cathode downward along the axial direction of the closed component. At the same time, drive the first rotary axis to rotate the closed component blank around its axis to complete the rough machining of the blade channel.

[0024] Step 3: Under the same work station, the partition power-on reversing feed matching system automatically switches to powering on the cathode for blade basin surface machining or blade back surface machining, driving the five-sided integrated cathode to the optimal feed position of the blade basin or blade back surface to be machined, keeping the five-sided integrated cathode fixed, and driving the first rotating shaft to rotate the closed component blank towards the corresponding cathode surface, completing the electrolytic finishing of the blade basin surface or blade back surface.

[0025] Step 4: Under the same work station, the partition power-on reversing feed matching system automatically switches to the other side to energize the cathode for processing the blade back or blade basin, driving the five-sided integrated cathode to the optimal feed position of the blade back or blade basin to be processed. Keeping the five-sided integrated cathode fixed, the first rotating shaft drives the closed component blank to rotate towards the corresponding cathode surface, completing the electrolytic finishing of the blade back or blade basin surface.

[0026] Step 5: Under the same work station, the partitioned power-on reversing feed matching system automatically switches to the hub surface machining cathode or the blade crown surface machining cathode to start the power, drive the five-sided integrated cathode to the optimal feed position of the hub surface or the blade crown surface, keep the closed component blank fixed, drive the second motion axis to make the five-sided integrated cathode move towards the surface to be machined in the machining direction, and complete the electrolytic finishing of the hub surface or the blade crown surface;

[0027] Step Six: Under the same work station, the partitioned power-on reversing feed matching system automatically switches to the cathode for blade crown surface machining or hub surface machining, drives the five-sided integrated cathode to the optimal feed position of the blade crown or hub surface, keeps the closed component blank fixed, and drives the second motion axis to make the five-sided integrated cathode move towards the surface to be machined in the machining direction, and completes the electrolytic finishing of the blade crown or hub surface;

[0028] Step 7: After the full profile machining of the blades in a channel is completed, the partitioned power-on reversing feed matching system automatically de-energizes all the end face machining cathodes, blade basin machining cathodes, blade back machining cathodes, hub machining cathodes, and blade crown machining cathodes. It drives the five-sided integrated cathode to reset to the initial machining position according to the set retraction program, and drives the closed component blank to rotate 360 / n deg, where n is the number of blades in the closed component. Repeat steps 2 to 7 above to finally complete the machining of all blades in the closed component blank.

[0029] Step 8: Turn off the electrolyte circulation system and exhaust system, and turn off the electrolytic machining power supply and machine tool.

[0030] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0031] (1) An integrated cathode structure is provided. The five-sided integrated cathode consists of five parts: end face processed cathode, blade basin surface processed cathode, blade back surface processed cathode, hub surface processed cathode and blade crown surface processed cathode. Each part is insulated from each other and is connected and fixed into a whole by insulating support blocks, realizing the "form" as a whole and the "electrical" separation, which simplifies the cathode design.

[0032] (2) A method for integrated roughing and finishing of the entire surface of a closed component is provided. The five-sided integrated cathode is independently energized. Through the partitioned energizing and reversing feed matching system, the segmented energizing of the cathodes for different surface machining and the matching of different feed directions are realized at the same station. The cathodes of the surface are energized to machine the corresponding surface when feeding in the normal direction, and de-energized at other times. The electric field is discrete, local electrolysis is realized, and each machined surface can be dissolved in the normal direction, thus completing the integrated roughing and finishing of the entire surface.

[0033] (3) Integrated cathode in-situ continuous full-surface electrolytic machining is highly efficient, low-cost, and has a short processing cycle. In-situ continuous full-surface electrolytic machining avoids the traditional electrolytic machining of separate rough and fine cathodes, eliminating the need to design two sets of fixtures and two sets of cathodes, reducing cathode design and finishing time, and simplifying the full-surface machining process of closed component blade channels; it simplifies the cathode structure, making it easy to process, and allows for individual replacement of damaged cathodes; it allows for the design and machining of cathodes for blade profiles and their assembly, effectively improving processing efficiency while reducing production costs.

[0034] (4) Integrated cathode partitioned energizing in-situ continuous full-surface electrolytic machining ensures the machining allowance of the blade, improves machining accuracy and surface quality. The partitioned energizing machining method discretizes the electric field, realizes localized dissolution, effectively reduces stray corrosion in non-machined areas, ensures the uniformity of the machining allowance of the blade, and improves surface quality; in-situ continuous electrolytic machining only requires one clamping to realize the machining of all channels, avoids the error caused by repeated clamping and positioning processes, and improves the accuracy of electrolytic machining of closed components.

[0035] (5) The integrated cathode in-situ continuous full-surface electrolytic machining method has a wide range of applications and high machining flexibility. For other bladed disk parts, each machining cathode surface can be designed specifically.

[0036] The aforementioned closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool is characterized in that: each surface of the five-sided integrated cathode is machined by a dovetail groove structure and interlocked with an insulating fixed support, which can fix the cathode without damaging the cathode surface. At the same time, the dovetail groove structure acts as a reinforcing rib, effectively increasing the rigidity of the thin-walled cathode.

[0037] The aforementioned closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool is characterized in that: the size of the backflow groove is larger than the size of the end face machining cathode, and the depth is smaller than the thickness of the end face machining cathode. The backflow groove can be used to accommodate the protruding part of the integrated cathode, preventing the tool from hitting the blade while sealing the electrolyte, and effectively ensuring the stability of the electrolytic hydraulic pressure at the moment of penetration of the blade channel.

[0038] The aforementioned closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool is characterized in that: the aforementioned flexible sealing cover is composed of a base plate, a flexible sealing plate, and a cover plate from bottom to top; the base plate is closely attached to the upper end face of the sealing liquid chamber, and the base plate and the cover plate are provided with rectangular holes larger than the cathode rod. At the same time, the lower part of the cover plate has a groove with a depth greater than the thickness of the flexible sealing plate. The groove is used to accommodate the sliding of the flexible sealing plate inside. The cathode rod passes through the base plate, the flexible sealing plate, and the cover plate in sequence, pressing the cover plate. The flexible sealing cover can not only meet the requirement of moving synchronously with the cathode to achieve the function of flexible sealing, but also has a simple structure and is easy to disassemble. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the in-situ continuous full-surface electrolytic machining method for integrated cathode of closed components in this invention;

[0040] Figure 2 This is a schematic diagram of an integrated cathode structure;

[0041] Figure 3 This is a schematic diagram of the insulating pad structure;

[0042] Figure 4 This is a schematic diagram of the sealing chamber structure;

[0043] Figure 5 This is a partially enlarged view of the in-situ continuous full-surface electrolytic machining of the integrated cathode in this invention;

[0044] Figure 6 This is an exploded schematic diagram of the integrated cathode in-situ continuous full-surface electrolytic machining steps in this invention;

[0045] Figure 7 This is a schematic diagram of a flexible sealing cover structure;

[0046] Labels in the diagram: 1-First rotating shaft, 2-Support plate, 3-Insulating pad, 4-Closed component blank, 5-Five-sided integrated cathode, 6-Sealing chamber, 7-Flexible sealing cover, 8-Cathode rod, 9-Second motion shaft, 10-First motion shaft, 11-End face machined cathode, 12-Illustration back face machined cathode, 13-Hub face machined cathode, 14-Illustration basin face machined cathode, 15-Insulating fixed support, 16-Illustration crown face machined cathode, 17-Reverse flow groove, 18-Hub profile, 19-Illustration basin profile, 20-Illustration crown profile, 21-Illustration back face profile, 22-Flexible sealing cover plate, 23-Flexible sealing plate, 24-Flexible sealing cover bottom plate. Detailed Implementation

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0048] like Figure 1 and Figure 5 As shown, in the integrated cathode in-situ continuous full-surface electrolytic machining method of the present invention, the support plate 2 is installed on the first rotating shaft 1, the insulating pad 3 is tightly fixed to the support plate 2, and the backflow groove 17 is located on the upper end face of the insulating pad 3. When the blade channel is about to be processed through, the electrolyte is backflowed back to the processing area under the action of the backflow groove and will not spread. The closed component blank 4 is attached to and fixed to the upper end face of the insulating pad 3. The position of the blade channel to be processed corresponds one-to-one with the backflow groove 17. The bottom of the sealing chamber 6 is tightly attached to the upper end face of the closed component blank 4. The flexible sealing cover 7 is located on the upper part of the sealing chamber 6. The bottom plate 24 of the flexible sealing cover is tightly attached to the upper end face of the sealing chamber 6. The cathode rod 8 passes through the rectangular hole. While translating, it drives the flexible sealing plate 23 to cooperate with the flexible sealing cover cover 22 to achieve flexible sealing. The upper part of the cathode rod 8 is fixed on the first moving shaft 10 and connected to the liquid inlet pipe. The five-sided integrated cathode 5 comprises five processing parts: end face processed cathode 11, blade basin surface processed cathode 14, blade back surface processed cathode 12, hub surface processed cathode 13, and blade crown surface processed cathode 16, and an insulating fixing support 15. The five surface processed cathodes are installed and fixed on the insulating fixing support 15 and are isolated from each other to achieve independent current drawing. The initial position of the five-sided integrated cathode 5 is located in the annular cavity of the sealing liquid chamber 6 and is fixed on the cathode rod 8. The electrolyte flows from the inside of the cathode rod 8 through the hollow insulating fixing support 15 and is finally sprayed out from the flushing port of the end face processed cathode 11 to supply electrolyte to the processing area.

[0049] The integrated cathode in-situ continuous full-surface electrolytic machining process of this invention includes the following steps:

[0050] Step S1: Install and fix the support plate 2, insulating pad 3, closed component blank 4, and sealing liquid cavity 6 sequentially from bottom to top on the first rotating axis 1 of the machine tool. This can achieve a motion accuracy of 0.001° rotation step. The central rotation axis of the closed component blank 4 coincides with the axis of the first rotating axis 1 of the machine tool. Place the five-sided integrated cathode 5 and cathode rod 8 in the annular cavity of the sealing liquid cavity 6, install and fix the flexible sealing cover 7, connect the other end of the cathode rod 8 to the first motion axis 10, open the electrolyte circulation system and exhaust system, and connect the electrolytic machining power supply.

[0051] Step S2: Connect the five-sided integrated cathode 5 to the partitioned energized reversing feed matching system respectively. The cathode is mounted on the first motion axis 10 through the cathode rod 8. The first motion axis 10 is mounted on the second motion axis 9. The two can achieve a translational motion accuracy of 0.001mm.

[0052] Step S3: Start the cathode CNC platform and the closed component blank CNC platform, drive the five-sided integrated cathode 5 to the optimal feed position for machining the blade channel, turn on the electrolyte circulation system to introduce electrolyte, connect the electrolytic machining power supply, and automatically make the end face machining cathode 11 energized by the zone power-on reversing feed matching system. The CNC program runs according to the set machining trajectory to drive the five-sided integrated cathode to feed along the axial direction of the closed component blank. At the same time, the first rotating axis 1 assists in the rotational motion to complete the pre-machining of the blade channel.

[0053] Step S4-1: After the pre-machining of the blade channel is completed, the sectional power-on reversing feed matching system automatically controls the end face machining cathode 11 to de-energize and drives the five-sided integrated cathode 5 to move to the optimal feed position of the blade basin to be machined. Under the same station, the sectional power-on reversing feed matching system automatically energizes the blade basin surface machining cathode 14 and drives the closed component blank to rotate around the first rotating axis 1, so that it runs the CNC machining program according to the predetermined machining route to complete the electrolytic finishing of the blade basin surface.

[0054] Step S4-2: After completing the electrolytic finishing of the blade basin surface, the partition power-on reversing feed matching system automatically controls the blade basin surface machining cathode 14 to be de-energized and drives the five-sided integrated cathode 5 to move to the optimal feed position of the blade back surface to be machined. Under the same station, the partition power-on reversing feed matching system automatically energizes the blade back surface machining cathode 12 and drives the closed component blank 4 to rotate around the first rotation axis 1 in the opposite direction to step S4-1, so that it runs the CNC machining program according to the predetermined machining path to complete the electrolytic finishing of the blade back surface 21.

[0055] Step S4-3: After completing the electrolytic finishing of the blade back profile, the partitioned energizing and reversing feed matching system automatically controls the de-energization of the blade back machining cathode 12 and drives the five-sided integrated cathode 5 to move to the optimal feed position of the hub profile to be machined. Under the same station, the partitioned energizing and reversing feed matching system automatically energizes the hub surface machining cathode 13 and drives the second motion shaft 9 to feed the cathode along the normal direction of the hub surface, completing the electrolytic finishing of the hub profile 18.

[0056] Step S4-4: After completing the electrolytic finishing of the hub profile, the partitioned energizing and reversing feed matching system automatically controls the hub profile machining cathode 13 to be de-energized and drives the five-sided integrated cathode 5 to move to the optimal feed position of the blade crown profile to be machined. Under the same station, the partitioned energizing and reversing feed matching system automatically energizes the blade crown profile machining cathode 16 and drives the second motion shaft 9 to feed the cathode along the blade crown normal, completing the full-surface electrolytic machining of a single blade channel.

[0057] Step S5: After the full-surface machining of one blade channel is completed, the zoned energizing and reversing feed matching system automatically de-energizes the end face machining cathode 11, blade basin machining cathode 14, blade back machining cathode 12, hub machining cathode 13, and blade crown machining cathode 16. It then drives the five-sided integrated cathode to reset to the initial machining position according to the set retraction program, driving the closed component to rotate 360 / n deg, where n is the number of blades in the closed component. Step S4 is repeated to finally complete the full-surface electrolytic machining of all blades in the closed component blank 4. Finally, the electrolytic machining power supply is disconnected, the exhaust system is shut off, and the electrolyte circulation system is stopped to stop the electrolyte supply.

Claims

1. A closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool, characterized in that: Includes a five-sided integrated cathode (5), tooling fixtures, and a drive unit; The five-sided integrated cathode (5) includes an insulating fixed support (15) with a hollow structure, and an end-face processed cathode (11) is installed at its end. The end-face processed cathode (11) has a liquid outlet. The four sides of the insulating fixed support (15) are respectively equipped with a blade basin surface processed cathode (14), a blade back surface processed cathode (12), a hub surface processed cathode (13), and a blade crown surface processed cathode (16). The end-face processed cathode (11), blade basin surface processed cathode (14), blade back surface processed cathode (12), hub surface processed cathode (13), and blade crown surface processed cathode (16) are individually energized and do not conduct to each other. The tooling fixture includes a cathode rod (8), which is a hollow structure with an internal liquid inlet channel. The upper end of the five-sided integrated cathode (5) is fixed to the cathode rod (8), and the upper part of the cathode rod (8) is fixed to the first motion shaft (10) and connected to the liquid inlet pipe. The tooling fixture also includes a support plate (2), an insulating pad (3), a sealing cavity (6), and a flexible sealing cover (7) from bottom to top. The insulating pad (3) is close to the upper end face of the support plate (2) and has several backflow grooves (17) on it. The position of the backflow grooves corresponds to the position of the blade channel and is used to accommodate the cathode (11) that is extended after processing. The lower end face of the closed component blank (4) is in contact with the upper end face of the insulating pad (3). The sealing cavity (6) is close to the upper end face of the closed component blank and is used to accommodate the five-sided integrated cathode (5) to ensure that it does not interfere when it moves up and down. The flexible sealing cover (7) is located on the upper part of the sealing cavity (6). The driving device includes a first motion shaft (10), a second motion shaft (9), and a first rotation shaft (1); the first motion shaft (10) is fixed to the second motion shaft (9) and moves with it, and the direction of movement of the first motion shaft (10) is perpendicular to the direction of movement of the second motion shaft (9); the upper end face of the first rotation shaft (1) is connected to and fits against the support plate (2), which can drive the closed component blank (4) to rotate, and its axis is parallel to the direction of movement of the first motion shaft (10).

2. The closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool according to claim 1, characterized in that: All the surface-processed cathodes of the above-mentioned five-sided integrated cathode (5) are engaged with the insulating fixed support (15) through the dovetail groove structure.

3. The closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool according to claim 1, characterized in that: The size of the backflow groove is larger than the size of the end face-machined cathode, and the depth is smaller than the thickness of the end face-machined cathode (11).

4. The closed-type integrated cathode in-situ continuous full-surface electrolytic machining tool according to claim 1, characterized in that: The above-mentioned flexible sealing cover is composed of a flexible sealing cover base plate (24), a flexible sealing plate (23), and a flexible sealing cover cover (22) from bottom to top. The flexible sealing cover base plate (24) is close to the upper end face of the sealing liquid cavity (6). The flexible sealing cover base plate (24) and the flexible sealing cover cover (22) are provided with rectangular holes larger than the cathode rod (8). At the same time, the lower part of the flexible sealing cover cover (22) has a groove with a depth greater than the thickness of the flexible sealing plate (23). The groove is used to accommodate the flexible sealing plate (23) to slide inside. The cathode rod (8) passes through the flexible sealing cover base plate (24), the flexible sealing plate (23), and the flexible sealing cover cover (22) in sequence, and presses the flexible sealing cover cover (22). The cathode rod (8) drives the flexible sealing plate (23) to achieve flexible sealing while translating.

5. The method for in-situ continuous full-surface electrolytic machining of an integrated cathode for closed components according to claim 1, characterized in that: Step 1: Install the support plate (2), insulating pad (3), and closed component blank (4). Fix the five-sided integrated cathode (5) to the cathode rod (8). Install the five-sided integrated cathode (5), sealing chamber (6), and flexible sealing cover (7). Use a dial indicator to measure and position the fixture, closed component blank, and five-sided integrated cathode. Install the wire and complete the tool setting. Turn on the electrolyte circulation system and exhaust system, and turn on the electrolytic processing power supply; Step 2: Drive the five-sided integrated cathode (5) to the optimal feed position for blade channel machining. The partitioned energizing and reversing feed matching system automatically energizes the end face machining cathode (11). Then, drive the first motion axis (10) to feed the five-sided integrated cathode (5) downward along the axial direction of the closed component. At the same time, drive the first rotating axis (1) to rotate the closed component blank (4) around its axis to complete the rough machining of the blade channel. Step 3: Under the same work station, the partition power-on reversing feed matching system automatically switches to powering on the blade basin surface machining cathode (14) or the blade back surface machining cathode (12), driving the five-sided integrated cathode (5) to the optimal feed position of the blade basin or blade back surface to be machined, keeping the five-sided integrated cathode (5) fixed, driving the first rotating shaft (1) to drive the closed component blank (4) to rotate towards the corresponding cathode surface, completing the electrolytic finishing of the blade basin surface (19) or the blade back surface (21); Step 4: Under the same work station, the partition power-on reversing feed matching system automatically switches to the other side of the blade back surface machining cathode (12) or blade basin surface machining cathode (14) to drive the five-sided integrated cathode (5) to the optimal feed position of the blade back or blade basin surface to be machined. Keep the five-sided integrated cathode (5) fixed and drive the first rotating shaft (1) to drive the closed component blank (4) to rotate towards the corresponding cathode surface to complete the electrolytic finishing of the blade back surface (21) or blade basin surface (19). Step 5: Under the same work station, the partition power-on reversing feed matching system automatically switches to the hub surface machining cathode (13) or the blade crown surface machining cathode (16) to drive the five-sided integrated cathode (5) to the optimal feed position of the hub profile (18) or the blade crown profile (20), keep the closed component blank (4) fixed, drive the second motion shaft (9) to make the five-sided integrated cathode (5) move towards the surface to be machined in the machining direction, and complete the electrolytic finishing of the hub profile (18) or the blade crown profile (20); Step 6: Under the same work station, the partition power-on reversing feed matching system automatically switches to the cathode (16) for blade crown surface machining or the cathode (13) for hub surface machining to drive the five-sided integrated cathode (5) to the optimal feed position of the blade crown profile (20) or hub profile (18), keep the closed component blank (4) fixed, drive the second motion shaft (9) to make the five-sided integrated cathode (5) move towards the surface to be machined in the machining direction, and complete the electrolytic finishing of the blade crown profile (20) or hub profile (18); Step 7: After the full surface machining of the blades in a channel is completed, the partition power-on reversing feed matching system automatically de-energizes the end face machining cathode (11), blade basin machining cathode (14), blade back machining cathode (12), hub machining cathode (13), and blade crown machining cathode (16), and drives the five-sided integrated cathode (5) to reset to the initial machining position according to the set retraction program, and drives the closed component blank (4) to rotate 360 / n deg, where n is the number of blades of the closed component. Repeat steps 2 to 7 above to finally complete the machining of all blades of the closed component blank. Step 8: Turn off the electrolyte circulation system and exhaust system, and turn off the electrolytic machining power supply and machine tool.

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