Electrochemical machining device and gate electrode electrochemical machining method

Abstract

The application discloses an electrolytic machining device and a machine gate electrolytic machining method. The electrolytic machining device comprises a cathode assembly, a workpiece clamping assembly and an elastic buffer assembly. The workpiece clamping assembly is used for fixing and clamping the machine gate. The cathode assembly is arranged opposite to the machine gate, and a machining gap is arranged between the cathode assembly and the machine gate. The elastic buffer assembly comprises a connecting rod and an elastic buffer unit. The first end of the connecting rod is connected to a machine tool rotating shaft, the second end of the connecting rod is connected to the workpiece clamping assembly, the elastic buffer unit is arranged on the connecting rod and cooperates with the workpiece clamping assembly, and the workpiece clamping assembly is used for conducting the axial stress generated in the machine gate electrolytic machining process to the elastic buffer assembly for buffering and offsetting. In the electrolytic machining device, the cathode is not lost in the electrolysis process, the axial and radial deformation of the machine gate after electrolysis is small, the qualified rate of the machine gate is high, and the electrolytic machining device is very suitable for large-batch, efficient and low-cost manufacturing of thin-wall machine gates.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic machining of an aero-engine, in particular to an electrolytic machining device and a turbine bucket electrolytic machining method. BACKGROUND

[0002] The turbine bucket is an important part of an aero-engine, and the material thereof is usually a difficult-to-cut material such as a nickel-based high-temperature alloy. The turbine bucket has a thickness of less than 1 mm and is a typical thin-walled structural part. The outer surface of the thin-walled turbine bucket is usually designed with a large number of irregular bosses. At present, five-axis numerical control milling is mainly used to machine the bosses, and the tool is severely worn, the cost is high, and the machining efficiency is low, which cannot meet the requirements of mass production.

[0003] Electrolytic machining is a special machining method for realizing workpiece machining and forming by using the principle of metal electrochemical anode dissolution. Compared with other machining methods, electrolytic machining has the following characteristics: 1. The tool cathode is not theoretically worn and can be used unlimitedly; 2. The machining efficiency is high; 3. The machining surface quality is good; and 4. It is a non-contact machining method and does not introduce cutting stress, which is very suitable for thin-walled part machining. For the thin-walled turbine bucket part with bosses, the most commonly used process method at present is mask electrolytic machining technology, that is, an insulating protective layer is made on the surface of the part. The cathode is fixed and the turbine bucket is continuously rotated during electrolytic machining. Under the action of electrochemistry, the surface material of the turbine bucket is continuously dissolved. However, due to the shape difference and irregular distribution of the bosses on the surface of the turbine bucket, as well as the existence of electric field concentration around the bosses during electrolytic machining, the materials are removed inconsistently in different regions of the part, and the residual stress of the part after electrolytic machining is redistributed, which causes the axial and radial deformation of the turbine bucket, the roundness and the flatness of the end surface are unqualified, and the qualified rate of the part is reduced. Therefore, it is necessary to design an electrolytic machining device and method capable of inhibiting the deformation of the turbine bucket, inhibiting the deformation degree of the turbine bucket during electrolytic machining, and improving the qualified rate of the part. SUMMARY

[0004] The present application provides an electrolytic machining device and a turbine bucket electrolytic machining method to solve the technical problem of axial and radial deformation during the electrolytic machining of the turbine bucket.

[0005] According to one aspect of the present application, an electrolytic machining device for electrolytic machining of a turbine bucket of an aero-engine is provided, which comprises a cathode assembly, a workpiece clamping assembly and an elastic buffer assembly; the workpiece clamping assembly is used for fixing and clamping the turbine bucket, the cathode assembly is used for being arranged towards a to-be-machined position of the turbine bucket and having a machining gap between the turbine bucket; the elastic buffer assembly comprises a connecting rod, an elastic buffer unit and an axial limiting piece, the workpiece clamping assembly is movably mounted on the connecting rod, a first end of the connecting rod is used for being connected with a rotating shaft of a machine tool, the axial limiting piece is arranged at a second end of the connecting rod, the elastic buffer unit is arranged on the connecting rod and is used for elastically pressing and abutting the workpiece clamping assembly to the axial limiting piece, and the workpiece clamping assembly is used for conducting axial stress generated in the electrolytic machining of the turbine bucket to the elastic buffer assembly for buffering and offsetting.

[0006] Further, the elastic buffer unit comprises a spring and a sleeve, the connecting rod is sequentially provided with a first segment and a second segment along a length direction thereof, a diameter of the first segment is greater than that of the second segment, so as to form a limiting step between the first segment and the second segment, an inner diameter of the sleeve is matched with an outer diameter of the first segment, the sleeve is sleeved on the second segment and extends to the first segment, a limiting ring is arranged at an end of the sleeve away from the first segment, an inner diameter of the limiting ring is matched with the outer diameter of the second segment, the spring is sleeved on the second segment, a first end of the spring abuts against the limiting step, and a second end of the spring abuts against the limiting ring, and the sleeve is used for elastically pressing and abutting the workpiece clamping assembly to the axial limiting piece under the elastic force of the spring.

[0007] Further, the electrolytic machining device further comprises a support plate and a mounting plate, the elastic buffer assembly is provided in plurality, the plurality of elastic buffer assemblies are mounted on the support plate and are arranged in a circumferential direction of the support plate; the support plate is connected with the first ends of the plurality of connecting rods respectively, and the workpiece clamping assemblies are connected with the second ends of the plurality of connecting rods respectively.

[0008] The support plate is fixed on the mounting plate, and the mounting plate is connected with the rotating shaft of the machine tool.

[0009] Further, the cathode assembly comprises a cathode and a cathode seat, internal passages of the cathode and the cathode seat are communicated with each other, serving as inflow passages of electrolyte; a machining end face of the cathode is arrayed with a plurality of liquid outlet grooves, serving as outflow passages of electrolyte; and the liquid outlet grooves are used for outputting electrolyte to the machining gap.

[0010] Further, the workpiece clamping assembly comprises a clamp and a flange plate, the clamp is fixedly installed on the flange plate, and the clamp is used for installing the machine brake; the flange plate is provided with a connecting hole for the connecting rod to pass through, and the axial limiting piece and the elastic buffering unit abut against opposite surfaces of the flange plate respectively.

[0011] Further, the workpiece clamping assembly further comprises a pressing plate and an insulating plate, and the pressing plate and the insulating plate are arranged at two ends of the clamp respectively, and are used for fixing the two ends of the machine brake in the axial direction.

[0012] Further, the electrolytic machining device further comprises a positive anode protection device, the positive anode protection device comprises a sacrificial anode sheet and a low-voltage direct-current power supply, the sacrificial anode sheet is installed on the cathode assembly, the sacrificial anode sheet is connected to the positive pole of the low-voltage direct-current power supply, and the negative pole of the low-voltage direct-current power supply is used for being connected to the machine brake.

[0013] Further, the low-voltage direct-current power supply is a power supply with a voltage of 3-6V.

[0014] According to another aspect of the present application, a machine brake electrolytic machining method is also provided, comprising the following steps:

[0015] S1: using a three-coordinate measuring instrument to measure the roundness of the machine brake after electrolytic machining, marking the high point area of the machine brake deformation, and marking the corresponding area M on the mask sheet; using a three-coordinate measuring instrument to measure the roundness of the machine brake to be machined, and marking the low point area N;

[0016] S2: under the condition of darkroom and light shielding, coating the outer surface of the machine brake to be machined with a photosensitive ink, and drying;

[0017] S3: attaching the mask sheet to the surface of the machine brake to be machined, and overlapping the area M on the mask sheet with the low point area N on the machine brake to be machined;

[0018] S4: performing ultraviolet exposure on the machine brake to be machined with the mask sheet attached, and developing the machine brake to be machined in a sodium carbonate solution, and removing the ink in the electrolytic machining area.

[0019] S5: installing the machine brake to be machined on the electrolytic machining device, starting the power supply and the electrolyte system, driving the machine brake to be machined to rotate through the rotating shaft of the machine tool, and gradually electrolyzing the surface machining area of the machine brake under the electrochemical action.

[0020] Further, in S4, the soaking time of the machine brake is 25-35min, the concentration of the sodium carbonate solution is 20%, and the solution temperature is 35℃-50℃.

[0021] The present application has the following beneficial effects:

[0022] 1. The electrolytic processing device provided by the present application, by setting the elastic buffer assembly in the axial direction of the machine gate, the axial stress generated in the machine gate electrolysis process is transmitted to the elastic buffer assembly, under the buffering action of the elastic buffer assembly, the position of the machine gate in the axial direction changes slightly, the axial stress is buffered and offset, avoiding the axial deformation of the machine gate caused by rigid constraint; and the machine tool structure required for electrolytic processing is simple, the cathode has no loss during electrolysis, the machine gate processing efficiency is high, and it is very suitable for mass production, high efficiency and low cost manufacturing of thin-walled machine gate.

[0023] 2. The electrolysis method provided by the present application can effectively solve the problem of radial deformation of the machine gate after electrolytic processing, improve the size accuracy, and improve the qualified rate of machine gate processing; at the same time, the method can realize the overall machining and forming of a large number of irregular bosses on the surface of the machine gate.

[0024] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings that form a part of this application are intended to provide a further understanding of the present application, and the illustrative embodiments of the present application and their description are intended to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0026] Figure 1 is a structural schematic view of the electrolytic processing device of the present application;

[0027] Figure 2 is a structural schematic view of the array liquid outlet tank of the present application;

[0028] Figure 3 is a schematic view of the electric field distribution around the boss of the machine gate before and after the application of the active anode protection device of the present application;

[0029] Figure 4 is a schematic view of the mask sheet of the present application;

[0030] Figure 5 is a schematic view of the machine gate blank of the present application;

[0031] Figure 6 is a schematic view of the machine gate of the present application;

[0032] Figure 7 is a schematic view of the machine gate after electrolytic processing measured by a three-coordinate measuring instrument.

[0033] Wherein: 1, cathode seat, 2, cathode, 3, pressing plate, 4, clamp, 5, machine brake, 6, insulating plate, 7, flange plate, 8, locking nut B, 9, sleeve, 10, spring, 11, connecting rod, 12, support plate, 13, locking nut A, 14, mounting plate, 15, machining gap, 16, sacrificial anode sheet, 17, liquid outlet groove, 18, axial stress direction. DETAILED DESCRIPTION

[0034] The embodiments of the present application will be described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0035] Reference Figures 1 to 3 , the first aspect of the embodiments of the present application provides an electrolytic machining device for electrolytic machining of the machine brake 5 of the aero-engine, the electrolytic machining device comprises a cathode assembly, a workpiece clamping assembly and an elastic buffer assembly; the workpiece clamping assembly is used for fixing and clamping the machine brake 5, the cathode assembly is used for being directed to the to-be-machined position of the machine brake 5 and having a machining gap 15 between the machine brake 5; the elastic buffer assembly comprises a connecting rod 11, an elastic buffer unit and an axial limiting piece, the workpiece clamping assembly is movably mounted on the connecting rod 11, a first end of the connecting rod 11 is used for being connected with the rotating shaft of the machine tool, the axial limiting piece is arranged at a second end of the connecting rod 11, the elastic buffer unit is arranged on the connecting rod 11 and is used for pressing and abutting the workpiece clamping assembly to the axial limiting piece, and the workpiece clamping assembly is used for conducting the axial stress generated in the electrolytic machining process of the machine brake 5 to the elastic buffer assembly for buffering and offsetting.

[0036] The electrolytic machining device of the present application is provided with an elastic buffer assembly, wherein the connecting rod 11 in the elastic buffer assembly is connected with the rotating shaft of the machine tool and the workpiece clamping assembly respectively, so that the machine brake 5 can be rotated under the driving of the rotating shaft of the machine tool; the elastic buffer unit in the elastic buffer assembly has the effect of elastic deformation, the axial stress generated in the electrolytic machining process of the machine brake 5 is conducted to the elastic buffer assembly, the axial stress is offset through the elastic deformation of the elastic buffer assembly, so that the machine brake 5 moves slightly in the axial direction, and the axial deformation of the machine brake 5 caused by rigid constraint is avoided.

[0037] The cathode assembly is fixed and connected to the negative pole of the machine tool power supply, so that the cathode assembly is electrified with negative electricity; the machine gate 5 is installed on the rotating shaft of the machine tool through the workpiece clamping assembly and the elastic buffer assembly, and the rotating shaft of the machine tool is connected to the positive pole of the machine tool power supply, so that the machine gate 5 is electrified with positive electricity. The electrolyte in the electrolyte device flows through the machining gap 15 between the machine gate 5 and the cathode assembly, and the machine gate 5 rotates to perform electrolytic machining under the drive of the rotating shaft of the machine tool. In the electrolytic machining process, the boss on the surface of the machine gate 5 is gradually formed, and the inconsistent material removal, inconsistent wall thickness, different boss shapes and uneven distribution of each region on the surface of the machine gate 5 will cause the release of residual stress in the machine gate 5, resulting in axial stress, and the direction of the axial stress is 18 Figure 1 , the axial stress is transmitted to the elastic buffer assembly through the workpiece clamping assembly, the elastic buffer unit is compressed, and the position of the machine gate 5 in the axial direction changes slightly, so that the axial stress is buffered and offset. On the basis of realizing the rapid and efficient machining of the boss on the outer surface of the thin-walled machine gate 5, the electrolytic machining device can inhibit the deformation caused by the redistribution of residual stress, and further improve the part qualification rate.

[0038] Referring to Figure 1In the embodiment of the present application, the elastic buffering unit comprises a spring 10 and a sleeve 9, the connecting rod 11 is sequentially provided with a first section and a second section along the length direction thereof, the diameter of the first section is larger than that of the second section to form a limiting step between the first section and the second section, the inner diameter of the sleeve 9 is matched with the outer diameter of the first section, the sleeve 9 is sleeved on the second section and extends to the first section, the end of the sleeve 9 away from the first section is provided with a limiting ring, the inner diameter of the limiting ring is matched with the outer diameter of the second section, the spring 10 is sleeved on the second section, the first end of the spring 10 abuts against the limiting step, the second end of the spring 10 abuts against the limiting ring, and the sleeve 9 is used to press and abut the workpiece clamping assembly against the axial limiting piece under the elastic force of the spring 10. The sleeve 9 and the second section form a closed containing cavity, which not only can seal and protect the spring from foreign matters, but also can better limit the spring to avoid radial deformation of the spring and ensure the stress release effect. The sleeve body can be guided and matched with the first section, and the limiting ring on the sleeve can be guided and matched with the second section, so that the movement direction of the sleeve is limited and can only move axially without shaking in other directions, thereby improving the stability of the sleeve. When the elastic buffering unit is subjected to an axial stress, the sleeve 9 moves in the direction of the first section of the connecting rod 11 under the action of the axial stress to compress the spring 10, so that the axial position of the machine brake 5 changes slightly, the axial stress is buffered and offset, and the machine brake 5 is prevented from being rigidly constrained to produce axial deformation; when the axial stress disappears or the electrolytic machining is completed, the sleeve 9 can move in the direction of the second section of the connecting rod 11 under the reset action of the spring 10 to restore the original state.

[0039] In a more preferred embodiment of the present application, the electrolytic machining device further comprises a support plate 12 and a mounting plate 14, a plurality of elastic buffering assemblies are arranged, the plurality of elastic buffering assemblies are arranged on the support plate 12 and are arranged circumferentially along the support plate 12; the support plate 12 is respectively connected with the first ends of the plurality of connecting rods 11, and the workpiece clamping assemblies are respectively connected with the second ends of the plurality of connecting rods 11; specifically, the two ends of the connecting rod 11 are provided with threads, the end of the connecting rod 11 connected with the support plate 12 is locked by a locking nut A13, and the end of the connecting rod 11 connected with the workpiece clamping assembly is locked by a locking nut B8, so as to connect the entire workpiece clamping assembly and the elastic buffering assembly. The number of the elastic buffering assemblies in the present application is set according to the circumferential area of the machine brake 5 to improve the connection stability with the machine brake 5.

[0040] Further, the support plate 12 is fixed on the mounting plate 14, and the mounting plate 14 is connected with the machine tool rotating shaft. The support plate 12 is used to install the plurality of elastic buffering components into a whole, and then the elastic buffering components are connected to the machine tool rotating shaft through the mounting plate 14, and the machine tool rotating shaft is used to provide rotating power for the electrolytic machining of the machine gate 5.

[0041] Referring to Figure 1 and Figure 2 In the embodiment of the present application, the cathode assembly comprises a cathode 2 and a cathode seat 1, and the internal passages of the cathode 2 and the cathode seat 1 are communicated with each other as inflow passages of electrolyte; the machining section array of the cathode 2 is arranged with outflow grooves 17 as outflow passages of electrolyte; and the outflow grooves 17 are used to output electrolyte to the machining gap 15. The cathode seat 1 is connected with the cathode 2 by screws, electrolyte enters from the internal passage of the cathode seat 1, passes through the internal passage of the cathode 2, and flows out from the array outflow grooves 17 of the cathode 2, so as to flush the machining gap 15 between the cathode 2 and the machine gate 5, and provide necessary conditions for electrochemical reaction, while taking away electrolytic products and heat.

[0042] In the embodiment of the present application, the workpiece clamping assembly comprises a clamp 4 and a flange plate 7, the clamp 4 is fixedly installed on the flange plate 7, and the clamp 4 is used to install the machine gate 5; the flange plate 7 is provided with connecting holes for the connecting rods 11 to pass through, and the axial limiting members and the elastic buffering units respectively abut against opposite two sides of the flange plate. The clamp 4 is an I-shaped clamp 4, the I-shaped clamp 4 is installed on the flange plate 7 by screws, and the machine gate 5 is installed on the I-shaped clamp 4. The flange plate 7 is connected with the second ends of the plurality of connecting rods 11, so as to connect the workpiece clamping assembly and the elastic buffering assembly to form a whole, the end portions of the connecting rods 11 are locked by lock nuts B8, and the flange plate 7 abuts against the sleeve 9 of the elastic buffering unit, so as to conduct the axial stress generated in the electrolytic machining process of the machine gate 5 to the elastic buffering unit, and offset the axial stress through the elastic compression of the spring 10.

[0043] In another preferred embodiment of the present application, the workpiece clamping assembly further comprises a pressing plate 3 and an insulating plate 6, and the pressing plate 3 and the insulating plate 6 are respectively arranged at two ends of the clamp 4, and are used to fix the axial two ends of the machine gate 5. The large end surface of the machine gate 5 abuts against the insulating plate 6, and the small end surface of the machine gate 5 is pressed by the pressing plate 3, so as to fix the machine gate 5 on the I-shaped clamp 4, and improve the installation stability of the machine gate 5.

[0044] Referring to Figure 1In an embodiment of the present invention, the electrolytic machining apparatus further includes an active anodic protection device, comprising a sacrificial anode sheet 16 and a low-voltage DC power supply. The sacrificial anode sheet 16 is mounted on the cathode assembly and connected to the positive terminal of the low-voltage DC power supply, while the mechanical switch 5 is connected to the negative terminal of the low-voltage DC power supply. Furthermore, the low-voltage DC power supply has a voltage of 3-6V. Preferably, the low-voltage DC power supply has a voltage of 3V.

[0045] The low-voltage DC power supply is different from the machining power supply. The machining power supply is converted from 380V industrial AC power through the electrolytic machine's rectifier into DC power for electrolytic machining (the machining voltage is generally 18-24V, and the current varies depending on parameters such as the machining area, machining gap 15, voltage, and conductivity). The positive pole of the power supply is connected to the machine's rotating shaft and the machine switch 5; the negative pole is connected to the machine's feed shaft and the cathode 2. During electrolytic machining, the workpiece undergoes an oxidation reaction under the action of the electric field, gradually being removed in the form of ions, while the tool cathode 2 undergoes a reduction reaction. The hydrogen ions in the electrolyte gain electrons, generating hydrogen gas that precipitates on the surface of cathode 2, leaving cathode 2 intact. The low-voltage DC power supply is an external power supply with a voltage of less than 6V. The sacrificial anode protection voltage of the present invention is 3V.

[0046] See also Figure 3 The sacrificial anode piece 16 is made of TC4 titanium alloy. The sacrificial anode piece 16 is connected to the positive electrode of the low-voltage DC power supply, and the machine gate 5 is connected to the negative electrode of the low-voltage DC power supply. Figure 3 This is a schematic diagram of the electric field distribution around the boss of the machine gate 5. During electrolytic machining, the electric field around the boss is concentrated ( Figure 3 As shown in a), the current density is high, and the electrolytic machining material removal rate around the boss is higher than that in other areas, resulting in uneven wall thickness in each area of ​​the machine gate 5, which affects the uniformity of the residual stress distribution, and ultimately exacerbates the uneven redistribution of the residual stress of the machine gate 5, resulting in increased deformation of the part. When the low-voltage DC power supply is turned on during electrolytic machining of the machine gate 5, a low-voltage electric field can be applied between the cathode 2 and the machine gate 5, which can significantly improve the electric field concentration phenomenon around the boss and make the electric field distribution in each area of ​​the part surface tend to be consistent ( Figure 3 b), thereby improving the uniformity of wall thickness and reducing the deformation of parts.

[0047] During electrolytic machining, with the mechanical brake 5 connected to the anode and the cathode assembly connected to the cathode 2, the electric field lines are concentrated at the edge of the boss, resulting in a higher electrolytic intensity. Consequently, the material removal rate at the boss edge is greater than in the rest of the area, leading to an electric field edge effect. The electric field direction of the additional low-voltage DC power supply applied in the present invention is opposite to that during electrolytic machining. With the mechanical brake 5 connected to the cathode 2 and the cathode assembly connected to the anode, this opposite electric field direction shifts the electric field from the boss edge toward the periphery, making the electric field around the boss more uniform and thus improving the electric field edge effect.

[0048] Referring to Figures 4 to 7 According to the second aspect of the present application, a machine brake electrochemical machining method is provided, comprising the following steps:

[0049] S1: using a three-coordinate measuring instrument to measure the roundness of the machine brake after electrochemical machining, marking the high point area of the machine brake deformation, and marking the corresponding area M on the mask; using a three-coordinate measuring instrument to measure the roundness of the machine brake blank before electrochemical machining, and marking the low point area N; the machine brake after electrochemical machining described herein is a machine brake electrochemically machined by a conventional method, and the uneven distribution of residual stress of the machine brake due to the different shapes and distributions of the bosses on the outer surface of the machine brake causes the radial deformation of the machine brake. Generally speaking, the deformation of the machine brake is the largest at the area with the largest boss, therefore, these areas are marked by the mask;

[0050] S2: under darkroom light-proof conditions, the outer surface of the machine brake is coated with a photosensitive ink, and is dried;

[0051] S3: the mask is attached to the surface of the machine brake blank, the area M on the mask is overlapped with the low point area N of the machine brake blank, and the positions of the bosses with large deformation on the mask are corresponded with the low point areas on the machine brake blank blank, so as to inhibit the radial deformation of the machine brake through spatial position compensation;

[0052] S4: the machine brake with the mask attached is subjected to ultraviolet exposure, and is immersed in a sodium carbonate solution for development, the immersion time of the machine brake is 25-35 min, the concentration of the sodium carbonate solution is 20%, and the solution temperature is 35-50 DEG C, so as to remove the ink in the area to be electrochemically machined;

[0053] S5: the machine brake is installed on the electrochemical machining device, the pressing plate is pressed, the power supply and the electrolyte system are started, the machining parameters are set, the cathode is fixed, the machine brake is continuously rotated, and the surface of the machine brake to be machined is gradually machined away under the electrochemical action, so that the bosses are gradually formed.

[0054] The present application adopts three-coordinate measurement to measure the inner side of the machine brake electrochemically machined by a conventional method, referring to Figure 7 The area with the largest boss is the high point area with the largest deformation, and similarly, the three-coordinate measurement is performed on the machine brake blank before electrochemical machining, the high point area and the low point area are determined, and are marked on the machine brake blank. When the mask is attached, the boss area (i.e. the high point area of the deformation) of the mask is corresponded with the low point area of the machine brake blank, so as to compensate the electrochemical machining deformation in the spatial position, thereby reducing the deformation degree of the machine brake during electrochemical machining. It is verified by actual machining that the roundness of the machine brake electrochemically machined by the method of the present application is reduced from about 0.6 mm to about 0.15 mm, and the effect is remarkable.

[0055] The electrolysis method can effectively solve the problem of radial deformation after the machine gate electrolysis processing, improve the size precision, and improve the qualified rate of machine gate processing; meanwhile, the method can realize the overall processing and forming of a large number of and special bosses on the surface of the machine gate.

[0056] The above merely provides the preferred embodiments of the present application but not for limiting the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of electrochemical machining by a machine brake, characterized in that, The method comprises the following steps: S1: using a three-coordinate measuring instrument to measure the roundness of the gate after electrolytic machining, marking the high point area of the gate deformation, and marking the corresponding area M on the mask; Using a three-coordinate measuring instrument to measure the roundness of the gate to be machined, and marking the low point area N; S2: Under darkroom light-proof conditions, apply a photosensitive ink to the entire outer surface of the gate to be machined, and dry it; S3: Paste the mask on the surface of the gate to be machined, and align the area M on the mask with the low point area N on the gate to be machined; S4: Perform ultraviolet exposure on the gate to be machined with the mask pasted thereon, and develop the gate to be machined by immersing it in a sodium carbonate solution to remove the ink in the area to be electrolytically machined; S5: Install the gate to be machined on the electrolytic machining device, start the power supply and electrolyte system, and drive the gate to be machined to rotate through the rotating shaft of the machine tool, so that the machining area on the surface of the gate is gradually electrolyzed under the action of electrochemistry. The electrolytic machining device is used for electrolytic machining of a gate (5) of an aero-engine, and comprises a cathode assembly, a workpiece clamping assembly, and an elastic buffer assembly. The workpiece clamping assembly is used for fixing and clamping the gate (5), and the cathode assembly is used for being arranged towards a machining position of the gate (5) and having a machining gap (15) between the gate (5). The elastic buffer assembly comprises a connecting rod (11), an elastic buffer unit, and an axial limiting piece. The workpiece clamping assembly is movably installed on the connecting rod (11). A first end of the connecting rod (11) is used for being connected with a rotating shaft of a machine tool. The axial limiting piece is arranged at a second end of the connecting rod (11). The elastic buffer unit is arranged on the connecting rod (11) and is used for pressing and abutting the workpiece clamping assembly against the axial limiting piece. The workpiece clamping assembly is used for conducting axial stress generated in the electrolytic machining process of the gate (5) to the elastic buffer assembly for buffering and offsetting.

2. The electrochemical machining method of claim 1, wherein The elastic buffer unit comprises a spring (10) and a sleeve (9). The connecting rod (11) sequentially comprises a first segment and a second segment along a length direction thereof. A diameter of the first segment is greater than that of the second segment, so as to form a limiting step between the first segment and the second segment. An inner diameter of the sleeve (9) is matched with an outer diameter of the first segment. The sleeve (9) is sleeved on the second segment and extends to the first segment. An end of the sleeve (9) away from the first segment is provided with a limiting ring. An inner diameter of the limiting ring is matched with an outer diameter of the second segment. The spring (10) is sleeved on the second segment. A first end of the spring (10) abuts against the limiting step. A second end of the spring (10) abuts against the limiting ring. The sleeve (9) is used for pressing and abutting the workpiece clamping assembly against the axial limiting piece under the elastic force of the spring (10).

3. The electrochemical machining method of claim 2, wherein The electrolytic machining device further comprises a support plate (12) and a mounting plate (14), the plurality of elastic buffering components are arranged on the support plate (12) and are arranged circumferentially along the support plate (12); the support plate (12) is connected with the first ends of the plurality of connecting rods (11) respectively, and the workpiece clamping assembly is connected with the second ends of the plurality of connecting rods (11) respectively. The support plate (12) is fixed on the mounting plate (14), and the mounting plate (14) is connected with the rotating shaft of the machine tool.

4. The electrochemical machining method of claim 1, wherein The cathode assembly comprises a cathode (2) and a cathode seat (1), and the internal passages of the cathode (2) and the cathode seat (1) are communicated with each other as inflow passages of electrolyte; the machining end surface of the cathode (2) is arranged with a plurality of liquid outlet grooves (17) as outflow passages of electrolyte; the liquid outlet grooves (17) are used for outputting electrolyte to the machining gap (15).

5. The electrochemical machining method of claim 3, wherein The workpiece clamping assembly comprises a clamp (4) and a flange plate (7), the clamp (4) is fixedly installed on the flange plate (7), and the clamp (4) is used for installing the machine gate (5); the flange plate (7) is provided with a connecting hole for penetrating the connecting rod (11), and the axial limiting member and the elastic buffering unit abut against opposite two surfaces of the flange plate respectively.

6. The electrochemical machining method of claim 5, wherein The workpiece clamping assembly further comprises a pressing plate (3) and an insulating plate (6), the pressing plate (3) and the insulating plate (6) are arranged at two ends of the clamp (4) respectively, and are used for fixing the axial two ends of the machine gate (5).

7. The electrochemical machining method of claim 1, wherein The electrolytic machining device further comprises a positive anode protection device, the positive anode protection device comprises a sacrificial anode sheet (16) and a low-voltage direct-current power supply, the sacrificial anode sheet (16) is installed on the cathode assembly, the sacrificial anode sheet (16) is connected with the positive pole of the low-voltage direct-current power supply, and the negative pole of the low-voltage direct-current power supply is used for being connected with the machine gate (5).

8. The electrochemical machining method of claim 7, wherein The low-voltage direct-current power supply is a power supply with a voltage of 3-6V.

9. The electrochemical machining method of claim 1, wherein In the step S4, the machine gate is soaked for 25-35 min, the concentration of the sodium carbonate solution is 20%, and the temperature of the solution is 35-50 DEG C. In the step S4, the machine gate is soaked for 25-35 min, the concentration of the sodium carbonate solution is 20%, and the temperature of the solution is 35-50 DEG C.

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