Device and method for electrochemical machining of complex curved outer spiral surfaces of large aspect ratio all-metal rotors

Abstract

The present invention discloses an electrolytic machining device and method for the complex curved surface of an all-metal rotor with a large aspect ratio. Aiming at the problem of machining the complex curved surface of a metal rotor, the present invention designs a cathode structure for electrolytic machining of the complex curved surface of a metal rotor, which integrates guidance, insulation, and sealing. The cathode structure includes a three-jaw chuck, a cathode body, a self-propelled cathode box, a tailstock, a servo motor, and a guide rail support. The present invention also designs a self-propelled cathode box device, which consists of a cathode body, a telescopic sealing sleeve, a base support, and a drive, and can realize the machining of longer workpieces. The telescopic sealing sleeve allows the electrolyte to be concentrated and converged in the tailstock cavity and flow back to the electrolyte tank through the liquid outlet pipe, realizing efficient circulation of the electrolyte. The present invention can realize one-time rapid prototyping of the complex curved surface of the metal rotor under the conditions of low voltage, high current, small gap, and high electrolyte flow rate, with good machining surface quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolytic machining equipment manufacturing, and in particular relates to a device and method for electrolytic machining of an outer spiral complex curved surface of an all-metal rotor with a large aspect ratio. Background Art

[0002] As deep, ultra-deep, and geothermal wells continue to drill deeper, downhole temperatures are gradually rising, reaching or even exceeding 120-300°C. High temperatures can cause the screw drill tool material to expand, deform, wear, and corrode, placing a significant strain on its reliability and service life. All-metal screw drill tools offer high-temperature resistance far exceeding that of ordinary screw drills, significantly improving the drilling efficiency of deep, ultra-deep, and geothermal wells. Therefore, all-metal screw drill tool rotors have become an indispensable, key component in oil drilling.

[0003] The use of traditional CNC machining technology to process the outer contour of the all-metal screw drill rotor has problems such as severe tool wear, poor machining surface quality, and easy deformation.

[0004] The outer contour of the rotor processed by extrusion molding technology has problems such as poor surface quality and cracks, and can only be processed in multiple stages, and each stage is finally spliced ​​together, resulting in low precision.

[0005] Electrochemical machining is a method that utilizes the principle of electrochemical anodic dissolution. Under conditions of low voltage, high current, and high flow rate, it is not limited by the strength, hardness, and toughness of metal materials. It can achieve efficient and high-quality one-time rapid prototyping of complex surfaces of difficult-to-machine materials. It has the advantages of high machining efficiency, good surface quality, no tool cathode loss, no cutting stress, and no burrs. It provides an irreplaceable advanced machining method for large aspect ratio external helical complex curved shaft parts.

[0006] At present, the literature and reports on electrochemical machining of external spiral structures with large aspect ratios are as follows:

[0007] A method and equipment for electrolytic machining of slender titanium alloy shafts (patent number: ZL201410186767.8) uses a moving copper tube cathode to machine the surface of the slender shaft. However, this method can only perform surface finishing on workpieces with a small outer radius and simple surfaces, resulting in a small amount of removal. It cannot perform forming processing on the complex outer contours of large shaft parts.

[0008] The electrochemical machining method for the external cylindrical forming of shaft workpieces (patent number: ZL201910187963.X) first adopts an integral cathode fixed processing, and the integral cathode is the same axial length as the shaft workpiece, and then adopts a movable cathode fine processing. It is processed through a two-step method, but it does not design specific processing equipment and requires the replacement of the cathode; on the other hand, it can only optimize the surface roughness and cannot perform one-step forming processing on the complex outer contour of shaft parts.

[0009] The above documents only mention surface finishing or external cylindrical forming of workpieces with a small outer radius and simple surface. The cathode is driven by a hollow pull rod to achieve a combination of radial reciprocating motion and axial rotational motion of the cathode. The required hollow pull rod diameter should be larger than the blank diameter, which is difficult to manufacture and assemble. Moreover, they cannot achieve one-time forming of complex outer contours of long axis parts.

[0010] The literature and reports found on electrochemical machining of internal spiral structures with large aspect ratios are as follows:

[0011] A high-efficiency electrochemical machining device for complex spiral structures with large aspect ratios (patent number: ZL201911251481.2) proposes an electrochemical machining machine structure for special-shaped internal spiral parts. The electrochemical machining machine uses a pull rod to drive the cathode rotation and feed to achieve inner hole machining, and only a small force is required to achieve stable control of the cathode movement; however, the device cannot achieve the machining of external spiral complex curved surface shaft parts.

[0012] A high-efficiency precision electrolytic processing equipment and processing method for complex internal spiral wires of titanium alloy (patent number: ZL202010892863.X) solves the processing needs of shaft parts with internal spiral shapes and improves the surface quality and processing efficiency of parts, but cannot be used for the processing of complex curved surfaces of external spirals.

[0013] The above-mentioned documents only mention the electrolytic machining of internal spiral parts. In the electrolytic machining of internal spiral parts, the electrolyte is always in a closed space inside the workpiece, and a fixed support is used, so the sealing and conductivity problems are easier to solve; during the machining process, the hollow pull rod is too long, and there are high requirements for the machining stability; the equipment and machining method can only process shaft parts with internal spiral structure, but cannot realize the machining of shaft parts with complex curved surfaces of external spiral.

[0014] Compared with the electrochemical machining of internal spiral structures, the electrochemical machining of external spiral complex surfaces is to machine the outer surface of the workpiece. The workpiece is long, the machining process is more complicated, and the sealing of the electrolyte and the design of the conductive seat in the machining area become a difficulty. Under the conditions of long-term, high-pressure, and high-current continuous machining, if hollow pull rods are used for liquid supply and cathode drive, the machining stability will decrease as the working conditions become more complicated. Summary of the Invention

[0015] The purpose of the present invention is to address the shortcomings and problems of the existing technology and propose an electrolytic processing device and processing method for the complex curved surface of the outer spiral of a large aspect ratio all-metal rotor to solve the problem of one-time forming processing of the outer contour spiral line of the screw drill rotor.

[0016] To achieve the above-mentioned object, the technical solution adopted by the present invention is: an electrochemical machining device for an all-metal rotor with a large aspect ratio and a complex curved surface, comprising an electrochemical machining machine, a filtration system, a filter, a filtration system pump, a filtration system overflow valve, an electrolytic cell, an electrolyte overflow valve, an electrolyte pump, a power supply cooling device, a temperature controller, a DC power supply and a voltage stabilizer;

[0017] The electrochemical machining machine tool includes a three-jaw chuck, a tailstock, a conductive seat and a support seat. The workpiece is arranged between the three-jaw chuck and the tailstock, and is tightened by the top and locked by the sleeve locking handle. The three-jaw chuck presses the workpiece and drives the workpiece to rotate at a low speed; it also includes an external spiral complex curved surface electrochemical machining cathode and a telescopic sealing sleeve arranged on the inner side of the tailstock and sleeved on the workpiece; the external spiral complex curved surface electrochemical machining cathode is arranged on the support seat, and a guide rail support plate is provided at the bottom of the support seat to enable the support seat to move axially; the external spiral complex curved surface electrochemical machining cathode is arranged at the processing end of the workpiece, and the telescopic sealing sleeve is arranged between the external spiral complex curved surface electrochemical machining cathode and the tailstock;

[0018] The cathode for electrochemical machining of an external spiral complex curved surface comprises a front guide, a cathode body and a rear guide, wherein the cathode body is arranged between the front guide and the rear guide.

[0019] Furthermore, the inner wall of the cathode body is a spiral structure with sizes increasing from small to large, and is provided with a corresponding liquid increasing groove.

[0020] Furthermore, the above-mentioned front guide and rear guide are respectively ring-shaped, the front end of the front guide is connected to the liquid inlet pipe through bolts, and the rear end is connected to the cathode body through threads to form a whole; the rear end of the rear guide is connected to the telescopic sealing sleeve through studs, and the front end is connected to the cathode body through threads to form a whole.

[0021] Furthermore, the telescopic sealing sleeve is connected to the rear guide and the tailstock of the machine tool through studs, and is telescopic and retracted following the feeding of the cathode to achieve the return of the electrolyte.

[0022] Furthermore, the guide rail support plate drives the gear rack mechanism through an external servo motor to achieve axial feeding on the machine tool guide rail, thereby controlling the axial movement of the cathode for electrochemical machining of the external spiral complex curved surface.

[0023] Furthermore, the cathode for electrolytic machining of the external spiral complex curved surface passes through the process head at the left end of the workpiece and is sleeved on the workpiece, and the front guide is completely sleeved on the section to be processed and sealed by a sealing ring.

[0024] Furthermore, the three-jaw chuck is connected to the positive electrode of the DC power supply through a conductive box; the cathode of the external spiral complex surface electrolytic machining is connected to the negative electrode of the DC power supply through a conductive seat.

[0025] Furthermore, the cathode body is made of brass; the front guide and the rear guide are made of epoxy resin.

[0026] Furthermore, the above-mentioned method for electrochemically processing the outer spiral complex curved surface of the large aspect ratio all-metal rotor comprises the following steps:

[0027] 1) Connect the front and rear guides in the cathode for electrochemical machining of complex external spiral surfaces to the support base with bolts; then, use studs to install the telescopic sealing sleeve on the rear guide and tailstock; clean and dry the outer surface of the workpiece with the glued sleeve, and use a crane to install the process head with the sleeve on the three-jaw chuck;

[0028] 2) Turn on the power regulator, machine tool control and operation panel, and move the cathode of the external spiral complex surface electrochemical machining to the initial machining position by controlling the servo motor; move the tailstock of the machine tool to the other end of the workpiece to install the process head, press the top tip against the center cone hole of the process head, tighten it with the handwheel at the rear end of the tailstock, and then tighten the sleeve locking handle;

[0029] 3) Turn on the electrolyte pump, temperature controller and filtration system pump through the machine tool control and operation panel, introduce electrolyte into the pipeline, check whether the liquid circulation system is leaking, wait for the electrolyte to be adjusted to the appropriate processing temperature after the inspection is correct, and finally turn on the DC power supply and power cooling device to start electrolytic machining of the workpiece. The machining area of ​​the complex outer spiral and complex curved surface is a closed space. The electrolyte is pumped to make the electrolyte flow from the electrolytic cell through the liquid inlet pipe into the machining area, then flow out through the telescopic sealing sleeve and the liquid outlet pipe, and then enter the liquid outlet filter for filtration, and finally flow back to the electrolytic cell through the electrolyte pipeline;

[0030] 4) After the processing is completed, turn off the processing power supply, temperature controller, electrolytic cell pump and filtration system pump in sequence; wait for 3 to 5 minutes and then execute the tool retraction program through the machine tool control cabinet to retract the cathode of the external spiral complex surface electrolytic machining to the initial processing position; then use the crane to bear the weight of the workpiece, and also place a jack under the workpiece; loosen the sleeve locking handle, move the machine tailstock away, and control the cathode of the external spiral complex surface electrolytic machining away from the workpiece; finally, loosen the three-jaw chuck, disassemble the workpiece by crane and clean it. At this point, the entire processing process is completed.

[0031] Furthermore, the electrolysis voltage is 12V to 24V, the electrolyte temperature is 25°C to 30°C, and the electrolyte inlet pressure is 1.0MPa to 2.0MPa.

[0032] Compared with the prior art, the advantages of the present invention are as follows:

[0033] 1) Under the conditions of low voltage, high current, small gap and high electrolyte flow rate, the machining process of the present invention is free of contact between the tool and the workpiece, and there is no residual stress on the machined surface; and there is no cathode loss. This method can realize one-time rapid prototyping of the complex curved surface of the outer spiral of the rotor of the all-metal petroleum screw drill, which can effectively improve the machining quality, reduce the manufacturing cost, shorten the machining time and improve the machining efficiency.

[0034] 2) The cathode structure for electrolytic machining of external spiral complex curved surfaces of the present invention integrates guiding, insulation and sealing. The front guide, cathode body and rear guide parts are connected by means of threads with the same rotation direction as the workpiece during machining, ensuring that the connection of the various parts is reliable during machining. At the same time, the joints are sealed by gaskets, thereby ensuring stable and reliable operation of the entire machining device.

[0035] 3) Based on the electrolytic machining back-copy forming principle, the cathode body of this invention is designed as a complex internal helical surface. The cathode teeth have a reasonable transition from small to large size, meeting the requirements of roughing to finishing during machining. Simultaneously, the cathode body cross-section is arranged from large to small, which not only ensures a uniform gap during machining but also forms a convergent flow field as the electrolyte enters the machining gap from the front inlet hole to exit through the rear inlet hole. This ensures a stable machining process and significantly improves the surface machining quality of the part, achieving a surface roughness better than Ra0.8μm.

[0036] 4) The present invention adopts a self-propelled cathode box electrolytic processing device, which realizes the rotation of the workpiece by rotating the machine tool spindle, and the external servo motor drive device feeds the self-propelled cathode box axially. Through the two coordinated movements of axial rotation of the workpiece and radial feeding of the cathode body in the self-propelled cathode box, a one-time rapid prototyping processing of the complex curved surface of the outer spiral of the all-metal rotor with a large aspect ratio is achieved. Compared with the feeding method of using a pull rod to pull the cathode, the processing method using a self-propelled cathode box can realize the processing of longer-sized workpieces. When processed on the same machine tool, the processing length can be up to twice that of using a pull rod to pull, which greatly saves the machine tool's floor space. The introduction of the telescopic sealing sleeve allows the electrolyte to be concentrated in the tailstock cavity and flow back to the electrolyte tank through the outlet pipe, realizing efficient circulation of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of the processing device of the present invention;

[0038] Figure 2 Schematic diagram of the structure of the cathode of the present invention;

[0039] Figure 3 is a three-dimensional cross-sectional view of the cathode of the present invention;

[0040] Figure 4This is a schematic diagram of the structure of the cathode support and drive of the present invention;

[0041] Figure 5 This is a schematic diagram of the tailstock structure of this device;

[0042] Figure 6 This is the main view of the conductive seat of this device;

[0043] Figure 7 yes Figure 5 Left view of;

[0044] Figure 8 This is the main view of the telescopic sealing sleeve of the device;

[0045] Figure 9 yes Figure 8 Left view of;

[0046] Figure 10 It is a schematic diagram of the parts processed by this device.

[0047] In the figure, 1. three-jaw chuck, 2. sleeve, 3. workpiece, 4. liquid inlet filter, 5. liquid inlet pipe, 6. cathode for electrochemical machining of external spiral complex curved surface, 7. telescopic sealing sleeve, 8. tailstock, 9. liquid outlet pipe, 10. liquid outlet filter, 11. guide rail support plate, 12. guide rail, 13. insulating plate, 14. conductive seat, 15. copper plate, 16. support seat, 17. servo motor, 18. filtration system, 19. filter, 20. filtration system pump, 2 1. Filtration system overflow valve, 22. Electrolytic cell, 23. Electrolyte overflow valve, 24. Electrolyte pump, 25. Power supply cooling device, 26. Temperature controller, 27. DC power supply, 28. Power voltage stabilizer, 29. Control and operation panel, 30. Front guide, 31. Cathode body, 32. Rear guide, 33. Gasket, 34. Sealing ring, 35. Tip, 36. Sleeve locking handle, 37. Tip sleeve, 38. Auxiliary block, 39. Handwheel. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following detailed description of the apparatus and method for electrochemical machining of complex curved surfaces of an all-metal rotor with a large aspect ratio, in conjunction with the accompanying drawings and specific embodiments, is provided. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0049] This embodiment provides an electrochemical machining device for the external spiral complex curved surface of a large aspect ratio all-metal rotor. Figure 1, including an electrochemical machining machine, a filtration system 18, a filter 19, a filtration system pump 20, a filtration system overflow valve 21, an electrolytic cell 22, an electrolyte overflow valve 23, an electrolyte pump 24, a power supply cooling device 25, a temperature controller 26, a DC power supply 27, a voltage stabilizer 28 and a control and operation panel 29;

[0050] The electrochemical machining machine tool includes a three-jaw chuck 1, an external spiral complex surface electrochemical machining cathode 6, a telescopic sealing sleeve 7, a tailstock 8, a conductive seat 14, a support seat 16, and a servo motor 17; the external spiral complex surface electrochemical machining cathode 6, the telescopic sealing sleeve 7, the support seat 16, and the servo motor 17 constitute a self-propelled cathode box. The external spiral complex surface electrochemical machining cathode 6 includes a front guide 30, a cathode body 31, and a rear guide 32. The cathode body 31 is arranged between the front guide 30 and the rear guide 32. Figure 2 and Figure 3 shown.

[0051] The workpiece 3 is arranged between the three-jaw chuck 1 and the tailstock 8, and is tightened by the top 35 and locked by the sleeve locking handle 36. The three-jaw chuck 1 presses the workpiece and drives the workpiece 3 to rotate at a low speed; the insulating sleeve 2 is installed on the process head at the fixed end of the three-jaw chuck 1 by glue, and the outer diameter is consistent with the size of the section to be processed of the workpiece. At the end of the processing, the cathode body 31 is ensured to realize the whole section processing of the workpiece 3, saving processing materials. The three-jaw chuck 1 is connected to the positive pole of the DC power supply 27 through the conductive box; the cathode 6 for electrolytic processing of external spiral complex curved surfaces is connected to the negative pole of the DC power supply 27 through the conductive seat 14, as shown Figures 6-10 shown.

[0052] The cathode 6 for electrolytic machining of complex external spiral surfaces passes through the process head at the other end of the workpiece 3 and is sleeved on the workpiece. The front guide 30 is completely sleeved on the section to be machined, and the connection part is sealed by a sealing ring 34. The other end of the workpiece 3 is fixed by a tailstock 8; the front guide 30 and the rear guide 32 are connected to the cathode body 31 through threads, and the sealing of the joint is achieved by a gasket 33. The telescopic sealing sleeve 7 is connected to the rear guide 32 at one end through a stud, and the other end is connected to the tailstock 8, and the sealing of the joint is achieved by a gasket 33; the telescopic sealing sleeve 7 is arranged between the cathode 6 for electrolytic machining of complex external spiral surfaces and the tailstock 8. The telescopic sealing sleeve 7 is respectively connected to the rear guide 32 and the tailstock 8 of the machine tool through studs, and gradually expands and contracts with the feed of the cathode 6 to achieve centralized liquid return of the electrolyte.

[0053] The support seat 16 is connected to the rear guide 32 and the guide rail support plate 11 through a stud, and supports the cathode 6 for electrolytic machining of external spiral complex surfaces, and can match guide devices of different sizes through insulating bearings with through holes; the conductive seat 14 is connected to the insulating plate 13 through a stud to prevent current from flowing to the machine tool; the insulating plate 13 is fixed to the guide rail support plate 11 through a stud, and a guide rail support plate 11 is provided at the bottom of the support seat 16. The guide rail support plate 11 drives the gear rack mechanism provided inside the machine tool through an external servo motor 17 to realize axial feeding on the machine tool guide rail 12, and controls the axial movement of the cathode 6 for electrolytic machining of external spiral complex surfaces. Figure 4 shown.

[0054] The cathode body 31 is supported by brass, and the inner wall is an inner spiral surface, with the size increasing from small to large. A liquid-increasing groove corresponding to the internal cavity is provided on the cathode body to stabilize the flow field in the machining gap.

[0055] The front guide device 30 is made of epoxy resin and is annular. The front end is connected to the liquid inlet pipe 5 by bolts, and the rear end is connected to the cathode body by threads to form a whole.

[0056] The rear guide device 32 is made of epoxy resin and is annular. Its front end is connected to the cathode body through threads to form a whole, and its rear end is connected to the telescopic sealing sleeve 7 through studs.

[0057] The tailstock 8 is composed of a center 35, a sleeve locking handle 36, a center sleeve 37, an auxiliary block 38, and a handwheel 39. The center 35 is pre-placed in the center sleeve 37, with the right end close to the tail of the handwheel 39 and fixed in position by the sleeve locking handle 36. The handwheel 39 is installed in the tailstock 8 from the rear end through a thread, and the center 35 is pushed to fix the workpiece 3 by tightening the thread. The center sleeve 37 and the center 35 are sealed by the sleeve locking handle 36. Figure 5 shown.

[0058] The conductive seat 14 is provided with a water cooling channel. Water flows out of the power supply cooling device, passes through the liquid inlet, the cooling channel, the liquid outlet, the power supply cooling device, and finally flows back to the power supply cooling device to avoid ablation of the equipment due to excessive current.

[0059] The electrochemical machining device of the present invention realizes helical electrochemical machining of the outer contour of a full-metal rotor with a large aspect ratio by combining the rotational motion of the workpiece 3 and the axial feed motion of the cathode 6 .

[0060] The processing area of ​​the complex external spiral and complex curved surface of the present invention is a closed space. By using the electrolyte pump 24, the electrolyte flows from the electrolytic cell 22 into the processing area through the liquid inlet pipe 5, and then flows out through the telescopic sealing sleeve 7 and the liquid outlet pipe 9 (arranged on the tailstock 8), and then enters the liquid outlet filter 10 for filtration, and finally flows back to the electrolytic cell 22 through the electrolyte pipeline, thereby realizing the recycling of the electrolyte.

[0061] A processing method of an electrochemical processing device for an all-metal rotor with a large aspect ratio and a complex curved surface is as follows:

[0062] 1) Connect the front and rear guides of the cathode 6 in the electrolytic machining of the external spiral complex curved surface to the support base 16 through bolts; then, use studs to install the telescopic sealing sleeve 7 on the rear guide 32 and the tailstock 8; clean and dry the outer surface of the workpiece 3, to which the sleeve 2 has been glued, to prevent the cathode from short-circuiting due to surface debris during the machining process; then, use a crane to install the process head equipped with the sleeve 2 on the three-jaw chuck 1. Here, to ensure concentricity and safety, a jack can be placed under the workpiece 3 and removed after the workpiece is installed;

[0063] 2) Turn on the power regulator 28 and the machine tool control and operation panel 29, and install the cathode 6 for electrochemical machining of external spiral complex curved surfaces to the initial machining position by controlling the servo motor 17; move the machine tool tailstock 8 to the process head at the other end of the workpiece 3 for installation, and press the center tip 35 against the center cone hole of the process head. Tighten it with the handwheel 39 at the rear end of the tailstock 8, and then tighten the sleeve locking handle 36; note that the entire workpiece clamping process is carried out with the crane fully lifting the workpiece, and the crane is not removed until the workpiece clamping is completed;

[0064] 3) Turn on the electrolyte pump 24, temperature controller 26, and filtration system pump 20 through the machine tool control and operation panel 29, introduce electrolyte into the pipeline, check the liquid circulation for leakage, wait for the electrolyte to be adjusted to the appropriate processing temperature after the inspection is complete, and finally turn on the DC power supply 27 and power supply cooling device 25 to start electrolytic machining of the workpiece;

[0065] 4) After the processing is completed, turn off the processing power supply 27, temperature controller 26, electrolyte pump 24 and filtration system pump 20 in sequence; then, wait for 3 to 5 minutes and execute the tool retraction program through the machine tool control cabinet to retract the cathode 6 of the external spiral complex surface electrolytic machining to the initial processing position; then use a crane to bear the weight of the workpiece, and also place a jack under the workpiece 3 to avoid damage to the cathode and ejector pin due to crane operation errors; loosen the sleeve locking handle 36, move the machine tailstock 8 away, and control the cathode 6 of the external spiral complex surface electrolytic machining away from the workpiece 3; finally, loosen the three-jaw chuck 1, disassemble the workpiece 3 by the crane and clean it. At this point, the entire processing process is completed.

[0066] According to the analysis of the current electrolytic machining conditions of the internal spiral all-metal screw drill stator, the electrolytic voltage is set to 12V~24V, the electrolyte temperature is 25℃~30℃, the electrolyte inlet pressure is 1.0MPa~2.0MPa, and the main component of the electrolyte is NaCl.

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An electrochemical machining device for an all-metal rotor with a large aspect ratio and a complex curved surface, comprising an electrochemical machining machine, a filter system (18), a filter (19), a filter system pump (20), a filter system overflow valve (21), an electrolytic cell (22), an electrolyte overflow valve (23), an electrolyte pump (24), a power supply cooling device (25), a temperature controller (26), a DC power supply (27) and a voltage stabilizer (28); the electrochemical machining machine comprises a three-jaw chuck (1), a tailstock (8), a conductive seat (14) and a support seat (16); a workpiece (3) is arranged between the three-jaw chuck (1) and the tailstock (8), is tightened by a top (35) and locked by a sleeve locking handle (36), the three-jaw chuck (1) presses the workpiece and drives the workpiece (3) to rotate at a low speed, and is characterized in that: It also includes an external spiral complex curved surface electrolytic machining cathode (6) and a telescopic sealing sleeve (7) arranged on the inner side of the tailstock (8) and sleeved on the workpiece (3); the external spiral complex curved surface electrolytic machining cathode (6) is arranged on the support seat (16), and a guide rail support plate (11) is arranged at the bottom of the support seat (16) to enable the support seat (16) to move axially; the external spiral complex curved surface electrolytic machining cathode (6) is arranged at the machining end of the workpiece (3), and the telescopic sealing sleeve (7) is arranged between the external spiral complex curved surface electrolytic machining cathode (6) and the tailstock (8); The cathode (6) for electrochemical machining of an external spiral complex curved surface comprises a front guide (30), a cathode body (31) and a rear guide (32), wherein the cathode body (31) is arranged between the front guide (30) and the rear guide (32); The inner wall of the cathode body (31) is a spiral structure with sizes increasing from small to large, and is provided with a corresponding liquid-increasing groove; The front guide (30) and the rear guide (32) are respectively annular, the front end of the front guide (30) is connected to the liquid inlet pipe (5) by a bolt, and the rear end is connected to the cathode body by a thread to form a whole; the rear end of the rear guide (32) is connected to the telescopic sealing sleeve (7) by a stud, and the front end is connected to the cathode body by a thread to form a whole; The telescopic sealing sleeve (7) is connected to the rear guide (32) and the machine tool tailstock (8) respectively through studs, and is telescopic in response to the feeding of the cathode (6), thereby realizing the return of the electrolyte.

2. The electrochemical machining device for the external spiral complex curved surface of a large aspect ratio all-metal rotor according to claim 1, characterized in that: The guide rail support plate (11) drives a gear rack mechanism via an external servo motor (17) to achieve axial feeding on the machine tool guide rail (12), thereby controlling the axial movement of the cathode (6) for electrochemical machining of an external spiral complex curved surface.

3. The electrochemical machining device for an all-metal rotor with a large aspect ratio and complex curved surface according to claim 2, characterized in that: The cathode (6) for electrochemical machining of an external spiral complex curved surface passes through the left end of the workpiece (3) and is sleeved on the workpiece (3). The front guide (30) is completely sleeved on the section to be processed and sealed by a sealing ring (34).

4. The electrochemical machining device for an all-metal rotor with a large aspect ratio and complex curved surface according to claim 3, characterized in that: The three-jaw chuck (1) is connected to the positive pole of a DC power supply (27) through a conductive box; the cathode (6) of the external spiral complex curved surface electrolytic machining is connected to the negative pole of the DC power supply (27) through a conductive seat (14).

5. The electrochemical machining device for the external spiral complex curved surface of an all-metal rotor with a large aspect ratio according to claim 4, characterized in that: The material of the cathode body (31) is brass; the material of the front guide (30) and the rear guide (32) is epoxy resin.

6. The processing method of the electrochemical processing device for the external spiral complex curved surface of a large aspect ratio all-metal rotor according to claim 1 is characterized in that: The following steps are involved: 1) Connect the front guide (30) and the rear guide (32) in the cathode (6) for electrochemical machining of an external spiral complex curved surface to the support seat (16) through bolts; then, use studs to install the telescopic sealing sleeve (7) on the rear guide (32) and the tailstock (8); clean and dry the outer surface of the workpiece (3) with the glued sleeve (2), and use a crane to install the process head equipped with the sleeve (2) on the three-jaw chuck (1); 2) Turn on the power regulator (28) and the machine tool control and operation panel (29), and move the cathode (6) for electrochemical machining of an external spiral complex curved surface to the initial machining position by controlling the servo motor (17); move the tailstock (8) of the machine tool to the process head at the other end of the workpiece (3) for installation, and place the top (35) on the center cone hole of the process head, tighten it with the handwheel (39) at the rear end of the tailstock (8), and then tighten the sleeve locking handle (36); 3) Turn on the electrolyte pump (24), the temperature controller (26) and the filter system pump (20) through the machine tool control and operation panel (29), introduce electrolyte into the pipeline, check whether the liquid circulation system is leaking, wait for the electrolyte to be adjusted to a suitable processing temperature after the inspection is correct, and finally turn on the DC power supply (27) and the power supply cooling device (25) to start electrolytic processing of the workpiece. The processing area of ​​the complex outer spiral and complex curved surface is a closed space. The electrolyte is caused to flow from the electrolytic cell (22) through the liquid inlet pipe (5) into the processing area through the electrolyte pump (24), and then flow out through the telescopic sealing sleeve (7) and the liquid outlet pipe (9), and then enter the liquid outlet filter (10) for filtration, and finally flow back to the electrolytic cell (22) through the electrolyte pipeline; 4) After the processing is completed, turn off the processing power supply (27), the temperature controller (26), the electrolytic cell pump (24) and the filtration system pump (20) in sequence; wait for 3 to 5 minutes, and then execute the tool retraction program through the machine control cabinet to retract the cathode (6) of the electrolytic processing of the external spiral complex surface to the initial processing position; then use a crane to bear the weight of the workpiece, and also place a jack under the workpiece (3); loosen the sleeve locking handle (36), move the machine tailstock (8), and control the cathode (6) of the electrolytic processing of the external spiral complex surface to be away from the workpiece (3); finally, loosen the three-jaw chuck (1), and use the crane to disassemble the workpiece (3) and clean it. At this point, the entire processing process is completed.

7. The method for electrochemical machining of an all-metal rotor with a large aspect ratio and a complex curved surface according to claim 6, characterized in that: The electrolysis voltage is 12V~24V, the electrolyte temperature is 25℃~30℃, and the electrolyte inlet pressure is 1.0MPa~2.0MPa.

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