Segmented synchronous electrolytic machining device and method for air inlet / outlet edge of large-torsion-angle blade

Abstract

The invention relates to a segmented synchronous electrolytic machining device and method for air inlet / outlet edges of a large-torsion-angle blade, and belongs to the technical field of electrolytic machining. The device is characterized in that an air inlet / outlet edge with a large torsion angle is divided into two sections with small torsion angles along a certain specific section, and two cathodes are designed respectively, so that the two cathodes in different feeding directions are subjected to segmented synchronous electrolytic machining of the air inlet / outlet edge. The device mainly comprises a segmented synchronous feeding mechanism and air inlet / exhaust side tool cathodes, the segmented synchronous feeding mechanism is installed on a machine tool spindle, and single-direction feeding of the spindle can be converted into synchronous cross feeding of the two tool cathodes through a pair of wedge mechanisms; the tool cathode is installed at the front end of the segmented synchronous feeding mechanism, a main liquid inlet and an auxiliary liquid inlet are formed in the upper side and the lower side of a cathode shell respectively, and the main liquid inlet and the auxiliary liquid inlet and the blades form an open type electrolyte flow field. The problem that the air inlet / outlet edge of the large-torsion-angle blade cannot be subjected to electrolytic machining is solved, and the machining precision and machining efficiency of the air inlet / outlet edge are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrolytic machining, and in particular relates to a device and method for segmented synchronous electrolytic machining of an inlet / exhaust edge of a blade with a large twist angle. Background Art

[0002] Blades are one of the key components of modern aircraft engines. New aircraft engine blades often adopt increasingly complex structures such as wide chord and curved swept blades, with a large number of blades, large changes in profile curvature, end bends, and sweeps. The geometric accuracy and comprehensive quality requirements are getting higher and higher, especially for the increasingly stringent dimensional accuracy and geometric shape requirements at the inlet / exhaust edges of the blades, and the molding process and surface integrity assurance are becoming more and more difficult.

[0003] At present, the main processing methods for the inlet / exhaust edge are milling, grinding and electrolytic machining. Milling is a processing method that removes workpiece material through a high-speed rotating milling tool. With the development of multi-axis CNC machining technology, the application scope of milling has become more extensive. At present, it can be applied to the precision machining of twisted structures such as the inlet / exhaust edge of the blade. However, since milling is a contact processing, there is a macro-cutting force between the tool and the workpiece. When machining a smaller-sized inlet / exhaust edge structure, it will cause the workpiece to deform, reducing the machining accuracy. At the same time, if the tool shape and machining parameters are not properly selected, or the machining trajectory planning is unreasonable, it will cause knife marks and micro cracks on the workpiece surface. Grinding technology, as a precision shaping process, is often used for the precision machining of the inlet / exhaust edge of the blade. During machining, the inlet / exhaust edge needs to reserve a certain machining allowance in the previous process in advance. The inlet / exhaust edge is precisely trimmed by precision grinding technology to produce a high-precision, high-surface quality inlet / exhaust edge structure. However, the current inlet / exhaust edge grinding process is difficult to achieve automated production, and its processing efficiency needs to be further improved.

[0004] Electrolytic machining technology is a processing method for removing metal materials based on the principle of electrochemical anodic dissolution. During the processing, the anode workpiece is connected to the positive pole of the power supply, and the tool cathode is connected to the negative pole of the power supply. A very small processing gap is maintained between the two electrodes, and the electrolyte flows through the gap at a high speed. Under the action of the electric field, an oxidation-reduction reaction occurs on the surfaces of the two electrodes in the processing gap, in which an oxidation reaction occurs at the anode, and the metal material is removed in the form of ions; a reduction reaction occurs at the cathode, and hydrogen is precipitated. During the processing, the tool cathode is continuously fed, and the material on the surface of the workpiece is continuously removed and gradually formed. Electrolytic machining is a non-contact processing method that is not limited by the mechanical properties of the material. It has the characteristics of no cutting force and no cutting heat. It has a natural advantage in the processing of small-sized thin-walled parts, so it is very suitable for the processing of blade intake / exhaust edges.

[0005] The traditional method of processing the inlet / exhaust edge structure of a blade relies on the cathode of the blade basin and the cathode of the blade back to feed in opposite directions, so as to form the inlet / exhaust edge structure while processing the blade profile. However, since the curvature of the inlet / exhaust edge varies greatly compared with the blade profile, the electric field and flow field state at the inlet / exhaust edge are constantly changing during the actual processing, making it difficult to ensure the processing accuracy. The tangential feed electrolytic processing method of the inlet / exhaust edge is to feed the cathode of the special tool for the inlet / exhaust edge tangentially along the middle arc line of the blade to remove the processing allowance on the basis of the completed surface processing, thereby realizing the precision processing of the inlet / exhaust edge. This method has great advantages over the traditional two-way feed processing method in terms of cathode design and flow field design, and has great potential in the processing of the inlet / exhaust edge of blades.

[0006] In the patent "Three-element design method for the leading and trailing edge cathode for precision electrolysis of aircraft engine blades" (application number 202210632192.2, applicant Jiangsu Jicui Precision Manufacturing Research Institute Co., Ltd., inventors Wang Zhongheng, He Chao, Zhao Jianshe, Zhang Changhao, and Gao Weizheng), it is proposed to design the cathode by optimizing the three elements of the leading and trailing edge cathode design, reduce the number of cathode iterative corrections, and improve the processing accuracy of the leading and trailing edges of the blades.

[0007] In the patent "A method for designing electrodes for precision electrolytic machining of blade leading and trailing edges" (application number 201711249203.4, applicant China Aviation Industry Corporation Shenyang Liming Aero Engine Co., Ltd., inventors Liu Haibo, Huan Heng, Zheng Xin, Chen Dong, Zhang Yahua), the surface conductivity of the cathode at the leading and trailing edge electric field concentration points is changed through surface treatment to avoid the problem of difficulty in ensuring electrolytic machining accuracy due to electric field concentration and flow field disorder in the leading and trailing edge areas.

[0008] In the patent "A method for adaptively processing the leading and trailing edges of aircraft engine turbine blades" (application number 202110678545.8, applicant Jiangsu Jianghangzhi Aircraft Engine Parts Research Institute Co., Ltd., inventor Wu Jiang, Cao Chunxiao, Yan Xiaolin), a number of evenly distributed follow-up mechanisms are arranged in the swing mechanism, and the tool cathode and the leading edge cathode one and leading edge cathode two arranged inside can adaptively complete the precision electrolytic processing of the leading and trailing edges of the blades, thereby greatly improving the processing efficiency and processing accuracy.

[0009] The patent "A pulse dynamic electrolytic shaping device for the inlet / exhaust edge of a blade or an integral blade disk" (application number 202110617149.4, applicant Nanjing University of Aeronautics and Astronautics, inventors Zhu Di, Liu Jia, Wang Hao, and Wang Jingtao) proposes a pulse dynamic electrolytic machining device for tangential feed machining along the inlet / exhaust edge, which can enable the machining process to be carried out under conditions far smaller than the conventional machining gap, thereby significantly improving the contour accuracy of the inlet / exhaust edge of the blade.

[0010] In the patent "Tools and methods for precision electrolytic shaping of blade inlet / exhaust edges" (application number 202210402862.1, applicant Nanjing University of Aeronautics and Astronautics, inventors Wang Jingtao, Liu Jia, Zhu Di, Xu Zhengyang, Wei Haodi, Wang Jing), an integrated cathode with tangential feeding of the inlet / exhaust edge and a method for precision shaping of the inlet / exhaust edge are proposed. During the processing, electrolytic machining of the inlet / exhaust edge can be achieved without disassembling any tooling and tool setting devices, which improves the degree of automation of the inlet / exhaust edge electrolytic machining to a certain extent.

[0011] However, the current tangential feed electrolytic machining method still has defects in practical applications when machining blades with twisted blade shapes and large inlet / exhaust edge torsion angles. Currently, the cathode feed direction of the inlet / exhaust edge is along the angular bisector of the inlet / exhaust edge torsion angle. For blades with too large a torsion angle, this will cause the cathode machining angle of certain parts of the inlet / exhaust edge to be too large, making it impossible to evenly dissolve the arc of the inlet / exhaust edge. Therefore, in order to overcome the problem that high-precision electrolytic machining cannot be achieved for the inlet / exhaust edges of blades with large torsion angles, the present invention provides a segmented synchronous electrolytic machining device and method for the inlet / exhaust edges of blades with large torsion angles. Summary of the invention

[0012] Purpose of the invention: The purpose of the present invention is to overcome the bottleneck problem that high-precision electrolytic machining of the inlet / exhaust edges of large-twist-angle blades cannot be achieved, and to propose a segmented synchronous electrolytic machining device and method for the inlet / exhaust edges of large-twist-angle blades.

[0013] Technical solution: A method for synchronous electrochemical machining of the intake / exhaust edge of a large torsion angle blade, characterized in that: the large torsion angle blade is synchronously machined in sections, wherein the determination method of the segmentation section and the feeding direction of the tool cathode after segmentation are determined by the following methods: Step 1. Cut the tip section contour line and the root section contour line on the blade 3D model and project them on the same plane; Step 2. Draw a number of inscribed circles in the projected contours of the blade tip section contour line and the blade root section contour line; and fit the center arcs through the centers of the inscribed circles to form the center arcs of the blade tip section and the blade root section respectively; Step 3. At the intersection of the middle arc line of the blade tip section and the inlet edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line inlet edge tangent of the blade tip section; at the intersection of the middle arc line of the blade root section and the inlet edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line inlet edge tangent of the blade root section; at the intersection of the middle arc line of the blade tip section and the exhaust edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line exhaust edge tangent of the blade tip section; at the intersection of the middle arc line of the blade root section and the exhaust edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line exhaust edge tangent of the blade root section; Step 4. Take the angle bisector direction of the tangent of the mid-arc inlet edge of the blade tip section and the angle bisector direction of the tangent of the mid-arc inlet edge of the blade root section as the reference direction, and take the blade section whose mid-arc tangent direction is consistent with the reference direction as the dividing surface of the inlet edge; the angle bisector direction of the reference direction and the direction of the tangent of the mid-arc inlet edge of the blade tip section is the feed direction of the tool cathode on the blade tip side of the inlet edge, and the angle bisector direction of the reference direction and the direction of the tangent of the mid-arc inlet edge of the blade root section is the feed direction of the tool cathode on the blade root side of the inlet edge; The directions of the angle bisectors of the tangents of the mid-arc exhaust edge of the blade tip section and the tangents of the mid-arc exhaust edge of the blade root section are respectively used as reference directions, and the blade section whose direction of the mid-arc tangent is consistent with the reference direction is used as the dividing surface of the exhaust edge; the direction of the angle bisector of the reference direction and the direction of the tangents of the mid-arc exhaust edge of the blade tip section is the feeding direction of the tool cathode on the blade tip side of the exhaust edge, and the direction of the angle bisector of the reference direction and the direction of the tangents of the mid-arc exhaust edge of the blade root section is the feeding direction of the tool cathode on the blade root side of the exhaust edge.

[0014] The method for segmented synchronous electrolytic machining of the intake / exhaust edges of large twist angle blades is characterized in that: after segmentation, the intake edge blade tip side and the intake edge blade root side are processed simultaneously; or the exhaust edge blade tip side and the exhaust edge blade root side are processed simultaneously.

[0015] The device of the segmented synchronous electrochemical machining method for the inlet / exhaust edge of the large twist angle blade is characterized by: It includes a segmented synchronous feeding mechanism, a blade root side tool cathode, and a blade tip side tool cathode; the segmented synchronous feeding mechanism is composed of a spindle adapter block and a blade root side inclined wedge mechanism and a blade tip side inclined wedge mechanism; The blade root side inclined wedge mechanism is composed of a blade root side guide rail base, a blade root side cathode base, and a blade root side guide rod; the blade root side guide rail base is fixedly mounted on the machine tool platform, and the blade root side cathode base is mounted on the blade root side guide rail base through a corresponding guide rail slider; the blade root side guide rod is mounted in the inclined groove of the blade root side cathode base to form a pair of inclined wedge mechanisms, and the end face of the blade root side guide rod is mounted on the machine tool spindle through a spindle adapter block; the blade root side tool cathode is mounted on the corresponding blade root side cathode base; the blade root side inclined wedge mechanism angle is consistent with the feed direction of the blade root side tool cathode on the intake side or the feed direction of the blade root side tool cathode on the exhaust side; The blade tip side inclined wedge mechanism consists of a blade tip side guide rail base, a blade tip side cathode base, and a blade tip side guide rod; the blade tip side guide rail base is fixedly installed on the machine tool platform, and the blade tip side cathode base is installed on the blade tip side guide rail base through a corresponding guide rail slider; the blade tip side guide rod is installed in the inclined groove of the blade tip side cathode base to form a pair of inclined wedge mechanisms, and the end face of the blade tip side guide rod is installed on the machine tool spindle through a spindle adapter block; the blade tip side tool cathode is installed on the corresponding blade tip side cathode base; the angle of the blade tip side inclined wedge mechanism is consistent with the feed direction of the blade tip side tool cathode on the intake side or the feed direction of the blade tip side tool cathode on the exhaust side.

[0016] The method for segmented synchronous electrochemical machining of the inlet / exhaust edge of a large twist angle blade is characterized by comprising the following machining steps: Step 1: Install the segmented synchronous feeding mechanism on the machine tool, and connect the spindle adapter block 6) to the spindle of the machine tool; adjust the position of the two segmented tool cathodes by adjusting the position of the machine tool spindle, so that the cathode surfaces of the two tools form a complete and continuous cathode surface; Step 2: Install the blade blank in the fixture, measure and locate it, and perform tool setting, and keep the initial machining gap between the tool cathode on the blade tip side, the tool cathode on the blade root side and the blade blank; Step 3: The blade blank is connected to the positive electrode of the power supply, and the tool cathode on the blade tip side and the tool cathode on the blade root side are connected to the negative electrode of the power supply; the processing flow field adopts a double-side liquid inlet counterflow flow field, and the electrolyte is divided into four paths, which flow into the processing gap from the main liquid inlet on the blade tip side, the main liquid inlet on the blade root side and the auxiliary liquid inlet, flow through the inlet / exhaust edge, and freely flow out from the open outlet formed by the lower guide shell on the blade tip side, the lower guide shell on the blade root side and the blade; Step 4: During processing, the machine tool spindle pushes the blade tip side guide rod and the blade root side guide rod to feed in the horizontal direction at the same time; the inclined wedge mechanism formed by the blade tip side guide rod and the blade tip side cathode base converts the horizontal feeding of the blade tip side guide rod into the feeding of the blade tip side cathode base in the direction of the inclination angle of the blade tip side guide rail base, thereby driving the blade tip side tool cathode to approach the inlet / exhaust edge; the inclined wedge mechanism formed by the blade root side guide rod and the blade root side cathode base converts the horizontal feeding of the blade root side guide rod into the feeding of the blade root side cathode base in the direction of the inclination angle of the blade root side guide rail base, thereby driving the blade root side tool cathode to approach the inlet / exhaust edge; under the synchronous movement of the blade tip side tool cathode and the blade root side tool cathode and the action of electrochemical dissolution, the synchronous forming of the inlet / exhaust edge is realized; Step 5: Turn off the power supply, electrolyte circulation system and machine tool.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant features: (1) A method for tangential electrochemical machining of the inlet / exhaust edge of a blade with a large twist angle is proposed. The inlet / exhaust edge of a blade with a large twist angle is divided into two sections along a certain cross section to reduce the twist angle of each section of the inlet / exhaust edge, and then the two sections of the inlet / exhaust edge of the blade are tangentially electrochemically machined simultaneously. This method of segmented synchronous electrochemical machining of the inlet / exhaust edge of a blade effectively solves the problem of excessive deviation in the size of the inlet / exhaust edge of the blade due to the large twist angle when tangentially machining the inlet / exhaust edge of a blade with a large twist angle, which is caused by the large angle between the feed direction and the tangent direction of the arc in the cross-sectional profile.

[0018] (2) A device for synchronous electrochemical machining of the inlet / exhaust edge of a blade with a large torsion angle was designed. The linear motion of a single motion axis directly drives the cathodes of the two inlet / exhaust edges to move synchronously along a certain angle, which ensures the synchronization and consistency of the cathode feed of the two tools. This device can effectively complete the synchronous machining of the inlet / exhaust edge of a blade with a large torsion angle.

[0019] (3) The tangential electrolytic machining method for the inlet / exhaust edge of large-twist blades has a wide range of applications and high machining flexibility. For parts such as the inlet / exhaust edge of integral blisk blades and the inlet / exhaust edge of diffuser blades, the inlet / exhaust edge tool cathode can be designed specifically for machining. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a segmented synchronous feeding electrolytic machining device; Figure 2 It is a partial cross-sectional view of a segmented synchronous feed electrochemical machining device; Figure 3 Schematic diagram of segmented synchronous feeding of cathode on intake / exhaust sides; Figure 4 It is a schematic diagram of the blade inlet / exhaust edge segmentation surface; Figure 5 Schematic diagram of arc tangent and feed direction in each section; Figure 6 It is a schematic diagram of cathode feeding direction for synchronous feeding of each segment; Names of the numbers in the figure: 1. Guide rail base on blade root side, 2. Guide rail slider, 3. Cathode base on blade root side, 4. Guide rod on blade root side, 5. Guide rail base on blade tip side, 6. Spindle adapter block, 7. Guide rod on blade tip side, 8. Cathode base on blade tip side, 9. Cathode upper guide shell on blade tip side, 10. Cathode upper guide shell on blade root side, 11. Cathode lower guide shell on blade tip side, 12. Blade, 13. Cathode lower guide shell on blade root side, 14. Cathode insulating block, 15. Tool cathode on blade root side, 16. Tool cathode on blade tip side, 17. Section contour line of blade tip, 18. Segmented synchronous processing split surface, 19. Section contour line of split surface, 20. Section contour line of blade root. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0022] like Figure 1 and Figure 2As shown, the segmented synchronous feeding mechanism includes a blade root side inclined wedge mechanism, a blade tip side inclined wedge mechanism and a spindle adapter block 6. The two inclined wedge mechanisms mainly include: a blade tip side guide rod 7 and a blade root side guide rod 4 with opposite inclination angles, a blade tip side cathode base 8 and a blade root side cathode base 3 with inclined grooves corresponding to the guide rod inclination angles, two pairs of guide rail sliders 2 (only one pair is shown in the figure), and a blade tip side guide rail base 5 and a blade root side guide rail base 1 with opposite end face inclination angles. During installation, the guide rail bases 1 and 5 are fixedly mounted on the machine tool platform, the cathode bases 3 and 8 are respectively mounted on the guide rail bases 1 and 5 through the guide rail sliders, the blade root side guide rod 4 and the blade tip side guide rod 7 are respectively mounted in the inclined grooves on the blade root side cathode base 3 and the blade tip side cathode base 8 to form an inclined wedge mechanism, and the bottoms of the blade root side guide rod 4 and the blade tip side guide rod 7 are mounted on the machine tool spindle through the spindle adapter block 6. The tool cathode on the inlet / exhaust side includes a tool cathode 15 on the blade root side of the inlet / exhaust side and a tool cathode 16 on the blade tip side of the inlet / exhaust side. Each tool cathode includes a tool cathode body, a cathode insulating block, an upper guide shell with a main liquid inlet, a lower guide shell with an auxiliary liquid inlet, and the like. The upper and lower guide shells and the cathode insulating block are directly mounted on the tool cathode body, and there is no need for frequent disassembly and assembly during processing. The tool cathode 15 on the blade root side and the tool cathode 16 on the blade tip side are respectively mounted on the cathode base 3 on the blade root side and the cathode base 8 on the blade tip side, forming a complete segmented synchronous electrolytic machining device. During processing, the main spindle of the machine tool simultaneously pushes the blade root side guide rod 4 and the blade tip side guide rod 7 to feed in the horizontal direction. The blade root side guide rod 4 and the blade tip side guide rod 7 form a pair of inclined wedge mechanisms with the blade root side cathode base 3 and the blade tip side cathode base 8 respectively, which converts the horizontal feeding of the guide rod into the feeding of the blade root side cathode base 3 and the blade tip side cathode base 8 along the inclination angle direction of their respective guide rail bases, thereby driving the blade root side inlet / exhaust side tool cathode 15 and the blade tip side inlet / exhaust side tool cathode 16 to synchronously feed and process the inlet / exhaust side. During processing, the flow field adopts a double-side liquid inlet counterflow flow field, and the electrolyte is divided into four paths, which flow into the processing gap from the upper guide shell 10 on the blade root side and the 9 main liquid inlets and auxiliary liquid inlets on the upper guide shell on the blade tip side, respectively, flow through the inlet / exhaust side of the blade blank 12, and freely flow out from the open outlet formed by the lower guide shell 13 on the blade root side, the lower guide shell 11 on the blade tip side and the blade 14.

[0023] like Figure 4 and Figure 5 As shown, the method for determining the feeding direction of the cathode of the inlet / exhaust edge tool and the inlet / exhaust edge segmentation section of the blade includes the following steps: Step S1: intercept the tip section contour line 17 and the root section contour line 20 on the blade three-dimensional model and project them on the same plane, draw a number of inscribed circles in the two section contours, and fit the centers of all the inscribed circles into mid-arcs.

[0024] Step S2: Draw a tangent to the mid-arc line at the intersection of the mid-arc line and the inlet / exhaust edge toward the outside of the cross-sectional contour, with the direction of the angle bisector of the tangents to the mid-arc line of the tip section and the root section as the reference direction.

[0025] Step S3: The blade section whose mid-arc tangent direction is consistent with the reference direction is used as the dividing surface 18 of the inlet / exhaust edge, the direction of the bisector of the angle between the reference direction and the direction of the mid-arc tangent of the blade tip cross-sectional profile is the feed direction 1 of the tool cathode 16 on the inlet / exhaust edge tip side, and the direction of the bisector of the angle between the reference direction and the direction of the mid-arc tangent of the blade root cross-sectional profile is the feed direction 2 of the tool cathode 15 on the inlet / exhaust edge root side.

[0026] like Figure 1 and Figure 6 As shown, the segmented synchronous electrochemical machining method for the inlet / exhaust edge of a large twist angle blade of the present invention includes the following machining steps: Step 1: Install the segmented synchronous feeding mechanism on the machine tool, and connect the spindle adapter block 6 to the machine tool spindle; adjust the position of the two segmented tool cathodes by adjusting the position of the machine tool spindle, so that the cathode surfaces of the two tools form a complete and continuous cathode surface; Step 2: Install the blade blank 12 in the fixture, measure and position it, and perform tool alignment, and keep the initial machining gap between the tool cathode 16 on the blade tip side, the tool cathode 15 on the blade root side and the blade blank 12; Step 3: The blade blank 12 is connected to the positive electrode of the power supply, and the tool cathode 16 on the blade tip side and the tool cathode 15 on the blade root side are connected to the negative electrode of the power supply; the processing flow field adopts a double-side liquid inlet counterflow flow field, and the electrolyte is divided into four paths, which flow into the processing gap from the main liquid inlet on the blade tip side, the main liquid inlet on the blade root side and the auxiliary liquid inlet, flow through the inlet / exhaust edge, and freely flow out from the open outlet formed by the lower guide shell 11 on the blade tip side, the lower guide shell 12 on the blade root side and the blade; Step 4: During processing, the machine tool spindle pushes the blade tip side guide rod 7 and the blade root side guide rod 4 to feed in the horizontal direction at the same time; the inclined wedge mechanism formed by the blade tip side guide rod 7 and the blade tip side cathode base 8 converts the feeding of the blade tip side guide rod 7 in the horizontal direction into the feeding of the blade tip side cathode base 8 in the direction of the inclined angle of the blade tip side guide rail base 5, thereby driving the blade tip side tool cathode 16 to approach the inlet / exhaust edge; the inclined wedge mechanism formed by the blade root side guide rod 4 and the blade root side cathode base 3 converts the feeding of the blade root side guide rod 4 in the horizontal direction into the feeding of the blade root side cathode base 3 in the direction of the inclined angle of the blade root side guide rail base 1, thereby driving the blade root side tool cathode 15 to approach the inlet / exhaust edge; under the synchronous movement of the blade tip side tool cathode 16 and the blade root side tool cathode 15 and the action of electrochemical dissolution, the synchronous forming of the inlet / exhaust edge is realized; Step 5: Turn off the power supply, electrolyte circulation system and machine tool.

Claims

1. A method for synchronous electrochemical machining of the inlet / exhaust edges of large torsion angle blades, characterized in that: The blades with large twist angles are processed synchronously in sections, where the determination of the segmented sections and the feed direction of the tool cathode after segmentation are determined by the following methods: Step 1. Cutting a blade tip cross-sectional contour line (17) and a blade root cross-sectional contour line (20) on the blade three-dimensional model and projecting them on the same plane; Step 2. Draw a plurality of inscribed circles in the projected contours of the blade tip cross-section contour line (17) and the blade root cross-section contour line (20); and fit the center arcs through the centers of the inscribed circles to form the center arcs of the blade tip cross-section and the center arcs of the blade root cross-section respectively; Step 3. At the intersection of the middle arc line of the blade tip section and the inlet edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line inlet edge tangent of the blade tip section; at the intersection of the middle arc line of the blade root section and the inlet edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line inlet edge tangent of the blade root section; at the intersection of the middle arc line of the blade tip section and the exhaust edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line exhaust edge tangent of the blade tip section; at the intersection of the middle arc line of the blade root section and the exhaust edge, a middle arc line tangent is made to the outside of the section contour, which is called the middle arc line exhaust edge tangent of the blade root section; Step 4. Take the angle bisector direction of the tangent of the mid-arc inlet edge of the blade tip section and the angle bisector direction of the tangent of the mid-arc inlet edge of the blade root section as the reference direction, and take the blade section whose mid-arc tangent direction is consistent with the reference direction as the dividing surface of the inlet edge; the angle bisector direction of the reference direction and the direction of the tangent of the mid-arc inlet edge of the blade tip section is the feed direction of the tool cathode on the blade tip side of the inlet edge, and the angle bisector direction of the reference direction and the direction of the tangent of the mid-arc inlet edge of the blade root section is the feed direction of the tool cathode on the blade root side of the inlet edge; The directions of the angle bisectors of the tangents of the mid-arc exhaust edge of the blade tip section and the tangents of the mid-arc exhaust edge of the blade root section are respectively used as reference directions, and the blade section whose direction of the mid-arc tangent is consistent with the reference direction is used as the dividing surface of the exhaust edge; the direction of the angle bisector of the reference direction and the direction of the tangents of the mid-arc exhaust edge of the blade tip section is the feeding direction of the tool cathode on the blade tip side of the exhaust edge, and the direction of the angle bisector of the reference direction and the direction of the tangents of the mid-arc exhaust edge of the blade root section is the feeding direction of the tool cathode on the blade root side of the exhaust edge.

2. The method for segmented synchronous electrochemical machining of the inlet / exhaust edge of a large twist angle blade according to claim 1, characterized in that: After segmentation, the inlet blade tip side and the inlet blade root side are processed simultaneously; or the exhaust blade tip side and the exhaust blade root side are processed simultaneously.

3. A device for implementing the segmented synchronous electrochemical machining method of the large twist angle blade inlet / exhaust edge according to claim 2, characterized in that: It comprises a segmented synchronous feeding mechanism, a blade root side tool cathode (15), and a blade tip side tool cathode (16); the segmented synchronous feeding mechanism is composed of a spindle adapter block (6) and a blade root side inclined wedge mechanism and a blade tip side inclined wedge mechanism; The blade root side inclined wedge mechanism is composed of a blade root side guide rail base (1), a blade root side cathode base (3), and a blade root side guide rod (4); the blade root side guide rail base (1) is fixedly mounted on a machine tool platform, and the blade root side cathode base (3) is mounted on the blade root side guide rail base (1) via a corresponding guide rail slider; the blade root side guide rod (4) is mounted in an inclined groove of the blade root side cathode base (3) to form a pair of inclined wedge mechanisms, and the end surface of the blade root side guide rod (4) is mounted on the machine tool spindle via a spindle adapter block (6); the blade root side tool cathode (15) is mounted on the corresponding blade root side cathode base (3); the angle of the blade root side inclined wedge mechanism is consistent with the feed direction of the blade root side tool cathode on the intake side or the feed direction of the blade root side tool cathode on the exhaust side; The blade tip side inclined wedge mechanism is composed of a blade tip side guide rail base (5), a blade tip side cathode base (8), and a blade tip side guide rod (7); the blade tip side guide rail base (5) is fixedly mounted on a machine tool platform, and the blade tip side cathode base (8) is mounted on the blade tip side guide rail base (5) via a corresponding guide rail slider; the blade tip side guide rod (7) is mounted in an inclined groove of the blade tip side cathode base (8) to form a pair of inclined wedge mechanisms, and the end surface of the blade tip side guide rod (7) is mounted on the machine tool spindle via a spindle adapter block (6); the blade tip side tool cathode (16) is mounted on the corresponding blade tip side cathode base (8); and the angle of the blade tip side inclined wedge mechanism is consistent with the feed direction of the blade tip side tool cathode on the intake side or the feed direction of the blade tip side tool cathode on the exhaust side.

4. A method for processing a segmented synchronous electrolysis device for the inlet / exhaust edge of a large twist angle blade according to claim 3, characterized in that The following steps are involved: Step 1: Install the segmented synchronous feeding mechanism on the machine tool, and connect the spindle adapter block (6) to the spindle of the machine tool; adjust the position of the spindle of the machine tool and then adjust the cathode positions of the two segmented tools so that the cathode surfaces of the two tools form a complete and continuous cathode surface; Step 2: Install the blade blank (12) in a fixture, measure and position it, and perform tool alignment, and keep an initial machining gap between the tool cathode (16) on the blade tip side, the tool cathode (15) on the blade root side, and the blade blank (12); Step 3: The blade blank (12) is connected to the positive electrode of the power supply, and the tool cathode (16) on the blade tip side and the tool cathode (15) on the blade root side are connected to the negative electrode of the power supply; the processing flow field adopts a double-side liquid inlet counterflow flow field, and the electrolyte is divided into four paths, which flow into the processing gap from the main liquid inlet on the blade tip side, the main liquid inlet on the blade root side and the auxiliary liquid inlet, flow through the inlet / exhaust edge, and freely flow out from the open outlet formed by the lower guide shell (11) on the blade tip side, the lower guide shell (12) on the blade root side and the blade; Step 4: During processing, the machine tool spindle pushes the blade tip side guide rod (7) and the blade root side guide rod (4) to feed in the horizontal direction at the same time; the blade tip side guide rod (7) and the blade tip side cathode base (8) form an inclined wedge mechanism, which converts the blade tip side guide rod (7) feeding in the horizontal direction into the blade tip side cathode base (8) feeding in the direction of the inclined angle of the blade tip side guide rail base (5), thereby driving the blade tip side tool cathode (16) to approach the inlet / exhaust edge; the blade root side guide rod (4) and the blade root side cathode base (3) form an inclined wedge mechanism, which converts the blade root side guide rod (4) feeding in the horizontal direction into the blade root side cathode base (3) feeding in the direction of the inclined angle of the blade root side guide rail base (1), thereby driving the blade root side tool cathode (15) to approach the inlet / exhaust edge; under the synchronous movement of the blade tip side tool cathode (16) and the blade root side tool cathode (15) and the electrochemical dissolution effect, the inlet / exhaust edge is synchronously formed; Step 5: Turn off the power supply, electrolyte circulation system and machine tool.

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