Combined sleeve type cathode and blisk rough and fine integrated electrolytic machining method

Abstract

The invention relates to a combined sleeve type cathode and a blisk rough and fine integrated electrolytic machining method. The method is characterized in that the combined sleeve type cathode comprises an end face sleeve type cathode on the front side and a blade basin and blade back type face cathode on the two sides, all the cathodes are mutually insulated and independently powered, and the power-on state of all the cathodes depends on the feeding direction of the combined cathode. During machining, the end face sleeve type cathode on the front side is powered on firstly, the blade basin / blade back type face cathode is powered off, the combined sleeve type cathode is fed in the radial direction of the blisk, and rough machining of the blade is completed; and afterwards, the blade basin or blade back molded surface cathode is powered on, other cathodes are powered off, the combined sleeve type cathode is fed in the normal direction of the blade basin or the blade back, and finish machining of the blade basin or the blade back is completed. According to the method, an integrated tool cathode structure is adopted, rough and fine integrated machining of the blisk can be completed through one-time clamping and one machining procedure, the positioning precision is guaranteed, the design of a tool cathode and a tool clamp is simplified, and the machining efficiency and the machining precision are improved.

Description

Technical Field

[0001] The invention relates to a method for electrolytic machining of a combined sleeve-type cathode and an integral blade disk in an integrated roughing and finishing process, and belongs to the technical field of electrolytic machining. Background Art

[0002] The blisk is an important component of new aircraft engines. It integrates the blades and the disk into one, which greatly reduces the number of engine parts, significantly reduces the weight, and significantly enhances reliability and aerodynamic performance. Since the blisk is mostly made of difficult-to-process materials such as nickel-based high-temperature alloys, and the blades of the blisk have complex structural features such as spatial bending and torsion characteristics and variable cross-sectional profiles, it is extremely difficult to manufacture the blisk efficiently and accurately.

[0003] Electrolytic machining is a special machining technology based on the principle of electrochemical anodic dissolution to remove workpiece materials. Compared with traditional machining technology, electrolytic machining is a non-contact cold machining process with the advantages of no tool loss, high machining efficiency, good machining surface quality, and no restrictions on the hardness and strength of the anode material itself. It is very suitable for the efficient machining of complex surface structural parts of difficult-to-machine materials. Electrolytic machining has high machining efficiency and low machining cost in mass molding of high-strength and high-hardness materials such as high-temperature alloys and titanium alloys, and is widely used in the defense industry and aerospace manufacturing fields.

[0004] At present, the electrochemical machining process of the integral blade disk is generally divided into two processes: blade channel pre-machining and blade surface finishing. As the first process, the blade channel pre-machining is mainly aimed at removing most of the material of the workpiece blank and machining a blade blank with a certain allowance and precision. As the second process, the blade surface finishing is mainly aimed at further removing a small amount of allowance from the blade blank to achieve the machining accuracy requirements of the ideal surface.

[0005] ECM is an electrochemical machining method that removes excess material around the ideal surface of the workpiece through a formed cathode. In ECM, an inner cavity is machined on a metal sheet based on the shape of the pre-machined part and the electrochemical side corrosion gap. This hollow metal sheet is the tool cathode, and the inner cavity edge is the cathode machining edge. The part is formed by the side of the cathode machining edge. During the machining process, the positive and negative poles of the power supply are connected to the workpiece and the tool cathode respectively. The workpiece and the tool cathode move relative to each other under a given feed trajectory. The electrolyte flows at high speed in the machining gap. The workpiece material facing the cathode end face on the workpiece is removed, and the workpiece material corresponding to the cathode machining edge is retained, finally forming a complex part. Since one-time machining can shape the workpiece contour and has the characteristics of high material removal efficiency, ECM has become one of the mainstream processes for rough machining of integral blades.

[0006] Although trepanning electrochemical machining has many advantages, the cathode used in the trepanning electrochemical machining method is only the end face trepanning cathode for rough machining of the workpiece contour, so the workpiece still needs to be further finished after the trepanning machining is completed. In previous processing plans, the cathode for finishing is usually redesigned according to the blade profile, and a set of fixtures is redesigned according to the designed cathode and the movement process of the workpiece, or the workpiece after trepanning electrochemical rough machining is finished using traditional mechanical processing technology. The traditional method requires secondary clamping of the workpiece and redesign of the finishing plan, and there are many problems that need to be solved.

[0007] In the patent "Device and method for processing blades and surface microtextures by pulse electrolysis in one step" (application number 202210695493.X, applicant Changchun University of Science and Technology, inventors Ren Wanfei, Xu Jinkai, Tao Jin, Yu Huadong, Wang Manfei), the combination of cathode sheet and cathode body is used to realize the processing of equal-section blade contours and the manufacture of blade leading and trailing edge surface microtextures, and the blade processing and in-situ manufacturing of blade surface microtextures are realized through the same electrolytic equipment. In contrast, this patent adopts a combined sleeve cathode, which can realize the integrated rough and fine processing of the entire blade disk; at the same time, the combined sleeve cathode has a simple structure, is compact and delicate, and can move under the CNC system of the machine tool after installation without the need to install additional drive devices.

[0008] In the patent "An integral impeller electrolytic sleeve and forming processing device" (application number 202022635196.5 applicant Changzhou Xinjiang Intelligent Equipment Co., Ltd., inventor Xia Renbo Xu Bo Xia Jianbo), the sleeve-shaped cathode for rough machining of the integral blade disk, and the blade basin and blade back sheet cathode for fine machining of the blade profile are installed on the same machine tool. The blade disk blank can be clamped once to complete the rough and fine machining, reducing repeated positioning errors. In comparison, this patent uses a combined sleeve-shaped cathode with an integrated structure. Only one set of cathodes and one set of fixtures are needed. The rough and fine integrated machining of the integral blade disk can be completed in one processing step. It is easy to operate, has high processing efficiency, and low manufacturing cost.

[0009] In the patent "Double-sided combined double cathode and zoned electric control integral blade disk electrolytic processing method" (application number 202210306217.X applicant Nanjing University of Aeronautics and Astronautics, inventors Xu Zhengyang Shen Zhenyu Liu Jia Zhu Dong), a double-sided combined double-tool cathode is used to feed simultaneously for step-by-step electrolytic processing of the blade channel and blade profile of the integral blade disk, which improves the processing efficiency. In comparison, this patent only uses a combined sleeve cathode to achieve integrated rough and fine processing of the integral blade disk, with simple cathode structure design and movement form, low manufacturing cost, simple operation, and strong feasibility.

[0010] In the patent "A method for electrolytic machining of an integral blade disk" (application number 201811128151.X, applicant China Aviation Manufacturing Technology Research Institute, inventors Huang Mingtao, Zhang Mingqi, Cheng Xiaoyuan, Fu Junying), a cathode head including a blade basin profile cathode and a blade back profile cathode is used to first drive the machining tool to feed radially along the integral blade disk blank, electrolytically pre-machine the blade grid channel between the blades, and then drive the integral blade disk blank to rotate clockwise / counterclockwise around its axis to perform blade basin / blade back profile finishing. In comparison, the method used in the present invention belongs to sleeve electrolytic machining, and the proposed combined sleeve cathode and machining method can process a blade shape with a certain margin in one step, and then the blade profile can be finished by simple linear motion of the combined sleeve cathode. The tool cathode structure is simple and has a wide range of applications.

[0011] Through analysis, it can be seen that in order to shorten the processing cycle, simplify the cathode design steps and improve the processing efficiency, a new cathode structure and process method of electrolytic machining tools are urgently needed to realize the integrated rough and fine manufacturing of the integral blisk blades. Summary of the invention

[0012] Purpose of the invention: The purpose of the present invention is to simplify the cathode design steps of the electrolytic machining of the integral blade disk, improve the machining efficiency, shorten the machining cycle, reduce the clamping positioning error, ensure the machining accuracy, and propose a combined sleeve cathode and an integrated electrolytic machining method for roughing and finishing of the integral blade disk.

[0013] A combined sleeve-type cathode, characterized in that it includes an insulating plate, an insulating base, an end face sleeve-type cathode, a blade basin-type cathode, and a blade back-type cathode; the end face sleeve-type cathode is a hollow structure, the end face sleeve-type cathode is located on the front side of the insulating plate, the insulating base is located on the rear side of the insulating plate, and the blade basin-type cathode and the blade back-type cathode are respectively located on both sides of the insulating plate; the end face sleeve-type cathode, the blade basin-type cathode and the blade back-type cathode are insulated from each other and are respectively connected to their own lead-in poles, and each lead-in pole passes through the insulating base and is connected to a partition power control device.

[0014] The electrolytic machining method for the rough and fine integrated blade disk of the combined sleeve cathode is characterized by comprising the following processes: step one: installing the whole blade disk on a dividing table, installing the combined sleeve cathode on a machine tool spindle, rotating the whole blade disk by means of the machine tool dividing table, making the position of the first blade to be machined of the whole blade disk relative to the initial position of the combined sleeve cathode, and keeping a certain initial machining gap between the two; step two: connecting the whole blade disk blank to the positive pole of the power supply, connecting the combined sleeve cathode to the negative pole of the power supply through a partitioned power control device, and turning on the electrolyte supply Liquid system; Step 3: Perform the rough machining process of the first blade of the integral blade disk; the machine tool spindle drives the combined sleeve cathode to feed radially along the integral blade disk, that is, to move along the X-axis slide, and the partitioned power control device sensitively identifies the movement state at the same time, and only supplies power to the end face sleeve cathode, and completes the rough machining of the blade profile through the end face sleeve cathode, and preliminarily processes a blade blank with a certain margin; Step 4: Perform the blade profile finishing process; the combined sleeve cathode is in the same working position condition after the rough machining in step 3, and the machine tool spindle drives the combined sleeve cathode from the original The radial feed is converted into a normal movement along the blade basin or blade back surface, that is, movement along the Y-axis slide, and the partitioned power control device cuts off the power to the end face sleeve cathode, and only supplies power to the blade basin surface cathode or the blade back surface cathode, so as to carry out the blade basin or blade back surface finishing; when the blade basin or blade back surface processing is completed, the machine tool drives the combined sleeve cathode to move along the normal direction of the blade back or blade basin surface, and the partitioned power control device cuts off the power to the blade basin surface cathode or the blade back surface cathode, and only supplies power to the blade back surface cathode or the blade basin surface cathode, so as to realize the blade back or blade basin surface finishing, in one addition Complete the rough and fine integrated precision electrolytic machining of the first blade of the integral blade disk in the process; Step 5: After the processing of the first blade in Step 4 is completed, the combined sleeve cathode returns to the initial processing position, and drives the dividing turntable to rotate the integral blade disk blank around the center of the blank by 360° / N degrees, N is the number of blades, so that it is just in the processing position of the second blade, and the rough and fine integrated machining of the second blade is carried out; Repeat the above processing steps to complete the rough and fine integrated machining of all blades of the integral blade disk in turn; Step 6: Turn off the power supply and the electrolyte supply system.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant features.

[0016] (1) A combined sleeve cathode structure is provided. The combined sleeve cathode is an integrated structure, the end sleeve cathode is located at the front side of the combined cathode, and the other two profile cathodes are located on both sides of the combined cathode and behind the end sleeve cathode. The three cathodes are insulated from each other by an insulating plate and are independently powered. The structure is simple and light, easy to manufacture, and easy to install and operate.

[0017] (2) A method for electrolytic machining of an integral blade disk with a combined sleeve cathode in the same machining cycle is provided. During machining, the front end face sleeve cathode is first energized, the blade basin / blade back cathode is de-energized, and the combined sleeve cathode is fed radially along the entire blade disk to complete the rough machining of the blade; then, the blade basin or blade back cathode is energized, the other cathodes are de-energized, and the combined sleeve cathode is fed along the normal direction of the blade basin or blade back to complete the fine machining of the blade basin or blade back. This method uses a combined sleeve cathode, and can complete the integrated rough and fine machining of the integral blade disk in one clamping and one machining process, ensuring positioning accuracy and improving machining efficiency and machining accuracy.

[0018] (3) The combined sleeve cathode and integrated blisk roughing and finishing electrolytic machining method has a wide range of applications. Since the combined sleeve tool cathode structure is simple and exquisite, the process method is easy to operate, the movement form is simple, and the application range is wide. It is not only suitable for the roughing and finishing integrated machining of outward-facing integral blisk blades, but also suitable for the roughing and finishing integrated machining of single blades and inward-facing integral blisk blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the assembly of the method for rough and fine integrated processing of the integral blade disk using a combined sleeve cathode in the present invention.

[0020] Figure 2 It is a schematic diagram of the assembly of the combined sleeve-type cathode structure of the present invention; Figure 3 It is an exploded view of the combined sleeve cathode structure; Figure 4 , Figure 5 , Figure 6 , Figure 7 This is a schematic diagram of the process of using a combined sleeve cathode to process an integral blade disk in the present invention, wherein Figure 4 is a schematic diagram of the initial processing state. Figure 5 This is a schematic diagram of the state at a certain moment in the middle of the rough machining process. Figure 6 This is a schematic diagram of the fine-machining blade back (or blade basin) profile. Figure 7 for Figure 6 A partial enlarged view of the processing area.

[0021] In the figure: 1. Combined sleeve cathode (101. end sleeve cathode; 102. end sleeve cathode lead-in column; 103. blade basin cathode; 104. blade basin cathode lead-in column; 105. blade back cathode; 106. blade back cathode lead-in column; 107. insulating plate; 108. insulating base); 2. zoned power control device; 3. cathode rod; 4. integral blade disk; 5. machine tool body (501. X-axis slide; 502. Y-axis slide; 503. Z-axis slide; 504. indexing turntable; 505. machine tool platform). DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] The process of electrolytic machining a workpiece using the "combined sleeve cathode and integral blade disc roughing and finishing integrated electrolytic machining method" of the present invention comprises the following steps: Step 1: Install the integral blade disk 4 on the indexing turntable 504, install the combined sleeve cathode 1 on the Z-axis slide 503 of the machine tool, and rotate the integral blade disk 4 through the machine tool indexing turntable 504 so that the first blade position of the integral blade disk 4 to be processed is opposite to the initial position of the combined sleeve cathode 1, and a certain initial processing gap is maintained between the two; Step 2: Connect the integral blade disk 4 to the positive pole of the power supply, connect the combined sleeve cathode 1 to the negative pole of the power supply through the partition power control device 2, and open the electrolyte supply system; Step 3: Perform the rough machining process of the first blade of the blisk 4. The machine tool spindle drives the combined sleeve cathode to feed radially along the blisk, that is, to move along the X-axis slide 501. The partitioned power control device 2 sensitively identifies the movement state at the same time, and only supplies power to the end face sleeve cathode 101. The rough machining of the blade profile is completed through the end face sleeve cathode 101, and a blade blank with a certain margin is initially machined; Step 4: Perform the blade surface finishing process. The combined sleeve cathode 1 is in the same working position condition after the rough machining in step 3 is completed. The machine tool spindle drives the combined sleeve cathode to change from the original radial feed to the normal movement along the blade basin or blade back surface, that is, along the Y-axis slide 502. The partitioned power control device 2 cuts off the power to the end face sleeve cathode 101, and only supplies power to the blade basin surface cathode 103 or the blade back surface cathode 105, to perform the blade basin or blade back surface finishing process; when the blade basin or blade back surface machining is completed, the machine tool drives the combined sleeve cathode 1 to move along the blade back or blade basin surface normal direction, and the partitioned power control device 2 cuts off the power to the blade basin surface cathode 103 or the blade back surface cathode 105, and only supplies power to the blade back surface cathode 105 or the blade basin surface cathode 103, to achieve the blade back or blade basin surface finishing process, and completes the rough and fine integrated precision electrolytic machining of the first blade of the integral blade disk in one machining process; Step 5: After the processing of the first blade in step 4 is completed, the combined sleeve cathode 1 returns to the initial processing position, and the indexing turntable 504 is driven to rotate the integral blade disk 4 around its center by 360° / N degrees (N is the number of blades) so that it is exactly at the processing position of the second blade, and the rough and fine integrated processing of the second blade is performed; the above processing steps are repeated to complete the rough and fine integrated processing of all blades of the integral blade disk 4 in sequence; Step 6: Turn off the power supply and electrolyte supply system.

Claims

1. A combined sleeve cathode, characterized in that: The invention comprises an insulating plate (107), an insulating base (108), an end face sleeve cathode (101), a blade basin cathode (103), and a blade back cathode (105); the end face sleeve cathode (101) is a hollow structure, the end face sleeve cathode (101) is located at the front side of the insulating plate (107), the insulating base (108) is located at the rear side of the insulating plate (107), and the blade basin cathode (103) and the blade back cathode (105) are respectively located at both sides of the insulating plate (107); the end face sleeve cathode (101), the blade basin cathode (103), and the blade back cathode (105) are insulated from each other and are respectively connected to respective lead-in poles, and the respective lead-in poles pass through the insulating base (108) and are connected to a partitioned power control device.

2. The electrolytic machining method for the combined sleeve-type cathode blisk of claim 1 is characterized by comprising the following steps: Step 1: Install the blisk on the indexing table, install the combined sleeve cathode on the machine tool spindle, rotate the blisk through the machine tool indexing table, make the first blade position of the blisk to be processed relative to the initial position of the combined sleeve cathode, and keep a certain initial processing gap between the two; Step 2: Connect the integral blade disk blank to the positive pole of the power supply, connect the combined sleeve cathode to the negative pole of the power supply through the partition power control device, and turn on the electrolyte supply system; Step 3: Perform the rough machining process of the first blade of the blisk; the machine tool spindle drives the combined sleeve cathode to feed radially along the blisk, that is, to move along the X-axis slide, and the partitioned power control device sensitively identifies the movement state at the same time, and only supplies power to the end face sleeve cathode, and completes the rough machining of the blade profile through the end face sleeve cathode, and initially processes a blade blank with a certain margin; Step 4: perform blade surface finishing process; the combined sleeve cathode is in the same working position condition after the rough machining in step 3 is completed, and the machine tool spindle drives the combined sleeve cathode to change from the original radial feed to the normal movement along the blade basin or blade back surface, that is, along the Y-axis slide, and the partitioned power control device cuts off the power to the end face sleeve cathode, and only supplies power to the blade basin surface cathode or the blade back surface cathode to perform blade basin or blade back surface finishing; when the blade basin or blade back surface machining is completed, the machine tool drives the combined sleeve cathode to move along the blade back or blade basin surface normal, and the partitioned power control device cuts off the power to the blade basin surface cathode or the blade back surface cathode, and only supplies power to the blade back surface cathode or the blade basin surface cathode to achieve blade back or blade basin surface finishing, and completes the rough and fine integrated precision electrolytic machining of the first blade of the integral blade disk in one machining process; Step 5: After the processing of the first blade in step 4 is completed, the combined sleeve cathode returns to the initial processing position, and the indexing turntable is driven to rotate the integral blade disk blank around the center of the blank by 360° / N degrees, where N is the number of blades, so that it is exactly at the processing position of the second blade, and the rough and fine integrated processing of the second blade is performed; the above processing steps are repeated to complete the rough and fine integrated processing of all blades of the integral blade disk in sequence; Step 6: Turn off the power supply and electrolyte supply system.

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