Blisk electrolytic machining process and electrolytic shaping machining equipment

Abstract

The application discloses a blisk electrolytic machining process and an electrolytic forming machining device, and relates to the technical field of electrolytic machining. The blisk electrolytic machining process comprises the following steps: electrolytic rough machining: machining blade blanks and blade row channels from an original blisk blank; electrolytic forming machining: using a cathode tool to uniformly and efficiently form a forming blank by machining the blade blanks after the rough machining; wherein the appearance of the cathode tool is designed according to the distribution of the excess amount of the surface of the blade blank to be machined; and electrolytic finishing machining: machining the forming blank into a blade with an accurate shape and profile. The application further provides an electrolytic forming machining device. The scheme provided by the application can improve the electrolytic machining efficiency and quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic machining, in particular to a blisk electrolytic machining process and an electrolytic shaping machining device. BACKGROUND

[0002] Blisk is a new type of structure of advanced aero-engine, which converts the traditional rotating disc and rotor blade from the assembled structure to the integrated structure. This change greatly reduces the number of engine parts, improves the power performance of the engine, and significantly reduces the weight of the engine itself. However, blisk usually has complex structural characteristics, high machining precision requirements, and the material used is mostly difficult to cut, which brings many difficulties to manufacturing.

[0003] At present, mechanical machining and electrolytic machining are two important ways of blisk machining. Compared with traditional mechanical machining, electrolytic machining has many advantages, such as: 1. Suitable for machining various difficult-to-cut metal materials; 2. Theoretically, the cathode tool can be used permanently and will not be worn out; 3. Electrochemical machining is a non-contact machining process, there is no macro cutting force and concentrated heat affected zone in the machining process, and the workpiece surface will not appear defects such as residual stress, recast layer and micro-cracks, so the machining surface quality is good. Therefore, electrolytic machining has been widely used in the production process of complex components such as aero-engine blades, blisks and casings. In the existing electrolytic machining process, the machining of blisk is usually divided into two processes of rough machining of blade channel and fine machining of blade surface. After the blade channel is electrolytically machined, the residual amount of the blade blank is usually extremely uneven. Due to the existence of genetic error in electrolytic machining, if the fine machining cathode cannot enter the balanced state in the limited machining allowance, the error caused by electrolytic machining of the blade channel cannot be completely removed, which is not conducive to ensuring the size accuracy and repeat accuracy of the final blade surface. However, due to the extremely narrow blade channel after machining and the extremely uneven residual amount of the blade blank surface, it is difficult for the subsequent fine machining to enter the balanced state. Therefore, it is of great significance to add electrolytic efficient shaping machining process based on non-equilibrium electrolytic machining law between rough machining of blade channel and fine machining of blade surface. The cathode machining designed by using the traditional method (cathode tool design method based on electrolytic machining equilibrium state) is easy to cause the machining residual amount to be still out of tolerance or the small residual amount area to be seriously overcut under the limited machining space and machining allowance of the blade channel.

[0004] Therefore, there is an urgent need for a new scheme to solve the above problems. SUMMARY

[0005] The purpose of the present application is to provide a blisk electrolytic machining process and an electrolytic shaping machining device to solve the problems existing in the prior art and improve the electrolytic machining efficiency and quality.

[0006] To achieve the above object, the present application provides the following scheme:

[0007] The present application provides a blisk electrochemical machining process, comprising:

[0008] Electrochemical rough machining: machining blade blanks and blade passage from original blisk blank;

[0009] Electrochemical finishing machining: using cathode tool to efficiently and uniformly finish the blade blank after rough machining to form a finishing blank; wherein the morphology of the cathode tool is designed according to the residual amount distribution of the surface to be machined of the blade blank;

[0010] Electrochemical finishing machining: machining the finishing blank to have precise shape and profile.

[0011] Preferably, the part of the cathode tool corresponding to the large residual amount area towards the surface to be machined is a convex structure, and the part corresponding to the small residual amount area is a concave, insulating or hollow structure.

[0012] Preferably, during the electrochemical finishing machining process, the machining parameters during machining are monitored in real time on the control panel, including but not limited to current density, electrolyte pressure, electrolyte flow, residual machining distance and feed speed.

[0013] Preferably, during electrochemical finishing machining, after machining of one blade is completed, the cathode tool exits the blade passage, the blisk mounting disc rotates by one index, the next blade blank enters the machining area, and the electrochemical finishing machining process is repeated until all blade blanks on the entire blisk are machined.

[0014] Preferably, for different models and different residual amount distributions of blisks, efficient finishing machining can be performed by changing the structure of the surface of the cathode tool.

[0015] The present application also provides an electrochemical finishing machining device, comprising an electrolyte circulation system, a machine tool machining system and a control system, the machine tool machining system comprising a machine tool body, a machine tool connecting shaft, a cathode tool and a blisk mounting disc, the cathode tool being installed on the machine tool body through the machine tool connecting shaft, the control system controlling the machine tool body to drive the cathode tool to be inserted into or exit from the blade passage, the morphology of the cathode tool being designed according to the residual amount distribution of the surface to be machined of the blade blank; using the cathode tool to efficiently and uniformly finish the blade blank after rough machining to form a finishing blank.

[0016] Preferably, the cathode tool is installed on the machine tool connecting shaft through a mounting seat, and the cathode tool is detachably arranged on the mounting seat.

[0017] Preferably, the cathode tool is a thin sheet electrode plate.

[0018] The present application has the following technical effects relative to the prior art:

[0019] (1) The present application adds a high-efficiency electrolytic sizing process between rough machining and finish machining to solve the problem of uneven distribution of the rough machining allowance of the blade of the blisk, which leads to poor finish machining precision. The process utilizes the non-equilibrium electrolytic machining law and the bidirectional feeding machining method to quickly homogenize the allowance of the blade rough surface; (2) The cathode of the process has a special structure (such as protrusions, pits, local insulation, and hollow structures), which can concentrate on removing the material in the large-allowance area of the rough surface while ensuring that the small-allowance area is less affected, so as to achieve the purpose of allowance homogenization with extremely small feeding amount; (3) The tool cathode adopts a thin sheet cathode, which can enter the blade channel through the coordinated movement of multiple degrees of freedom of the machine tool and realize fully automatic machining through numerical control programming, thereby improving the efficiency of the sizing process; (4) The process method and device are convenient to disassemble and replace, and can be applied not only to the production and machining of blisks but also to other production and manufacturing occasions where electrolytic finish machining cannot enter a balanced state, such as the production and manufacturing of engine diffusers. (5) A completely new "three-step" electrolytic machining process flow different from the existing "two-step" electrolytic machining process flow of the blisk is proposed, which integrates electrolytic high-efficiency sizing. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0021] Figure 1 for the electrolytic machining process flow of the blisk in the prior art;

[0022] Figure 2 for the electrolytic machining process flow of the blisk in the prior art;

[0023] Figure 3 for the electrolytic sizing process;

[0024] Figure 4 for the cross-sectional view of the cathode tool and the blade anode during electrolytic sizing;

[0025] Figure 5 for the structure of the cathode tool and the mounting seat;

[0026] Figure 6 A schematic diagram of another cathode tool and mounting base;

[0027] Figure 7 A schematic diagram of the structure for machining blade blanks and blade cascade channels, as well as the machine tool connecting shaft and base;

[0028] In the figure: 1-Cathode tool; 2-Blade blank; 11-Cathode tool on the back of the blade; 12-Cathode tool on the base of the blade; 31-Protrusion; 32-Dent; 4-Mounting base; 5-Blade disk blank; 6-Base; 7-Machine tool connecting shaft. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 The diagram illustrates the existing process flow of electrolytic machining of integral bladed disks, which employs a "two-step" process.

[0032] This invention provides an electrolytic machining process for integral bladed disks, such as... Figures 2-4 As shown, it includes:

[0033] Electrolytic rough machining: The blade blank 2 and the blade passage are machined from the original bladed disk blank 5;

[0034] Electrolytic shaping: The cathode tool 1 is used to efficiently homogenize and shape the rough-machined blade blank 2 to form a shaped blank; wherein, the shape of the cathode tool 1 is designed according to the allowance distribution on the surface to be machined of the blade blank 2.

[0035] Electrolytic finishing: machining the shaped blank into blades with precise shape and profile.

[0036] The whole blade disc electrochemical machining process provided by the application proposes a whole blade disc "three-step method" electrochemical machining process flow, which adds an efficient shaping machining process based on the existing "two-step method" process flow. The machining stability and precision of the whole blade disc with a higher twisted blade surface can be greatly improved. Specifically, the special structure on the cathode tool 1 for electrolytic shaping corresponds to the large excess area and small excess area on the blade blank 2. This special cathode structure can efficiently remove the material in the large excess area of the blank and ensure that the material in the small excess area is less affected, so that the excess uniformity of the blade blank 2 can be completed in a very short machining time. After efficient shaping machining, the excess difference of the blade blank 2 is significantly reduced, which is beneficial to the electrolytic machining to reach the equilibrium state quickly during the finishing machining, and then ensures the repeat accuracy and profile size accuracy of the finished blade.

[0037] In the electrochemical shaping machining step, the process feature is to use a special shaping cathode to perform efficient excess uniformity shaping on the rough-machined blade blank 2. The efficient shaping machining of the whole blade disc blade blank 2 can be based on the non-equilibrium state machining rule of electrochemical machining. In a few minutes, the material in the large excess area of the blank is quickly removed in the narrow blade passage and under the condition of limited machining excess, while the material in the small excess area is less affected, so as to quickly reduce the excess difference and achieve the purpose of uniformizing the excess distribution. The excess difference of the blade blank 2 is quickly reduced. This is beneficial to the electrolytic machining to reach the equilibrium state quickly during the finishing machining, and then ensures the repeat accuracy and profile size accuracy of the finished blade of the whole blade disc.

[0038] During machining, two thin sheet cathode tools 1 are usually used, which are a blade back cathode tool 11 and a blade basin cathode tool 12. Due to the special structure of the thin sheet, it can be inserted into the narrow blade passage of the whole blade disc and perform bidirectional feeding, translation, yawing and rotation and other movements. The thin sheet cathode tool 1 moves relative to the blade blank 2 in the narrow blade passage. This thin sheet cathode tool 1 can not only overcome the narrow problem of the whole blade disc blade passage, but also facilitate precise movement in the blade passage through the machine tool motion shaft. The efficient shaping machining process method for the complex profile of the whole blade disc has high shaping efficiency and good effect. At the same time, the thin sheet cathode tool 1 is easy to replace. This process method can be applied not only to the production and machining of whole blade discs, but also to other production and manufacturing occasions where electrolytic machining cannot reach the equilibrium state, such as the production and manufacturing of an aero-engine diffuser.

[0039] In some embodiments, as shown in Figures 5-6 The part of the cathode tool 1 corresponding to the large excess area towards the surface to be machined is a convex structure, and the part corresponding to the small excess area is a concave, insulating or hollow structure.

[0040] Understandably, the aforementioned raised, recessed, insulating, or hollowed-out structures are designed to adapt to the allowance distribution on the surface to be processed. That is, this special structure helps to quickly remove the material in the large allowance area of ​​the blank, while ensuring that the material in the small allowance area is less affected, thereby completing the uniformization of the allowance of the blade blank 2 in a very short processing time.

[0041] In some embodiments, during the electrolytic shaping process, various processing parameters are monitored in real time on the control panel. These processing parameters include, but are not limited to, current density, electrolyte pressure, electrolyte flow rate, remaining processing distance, and feed rate.

[0042] In some embodiments, during electrolytic shaping, after the processing of one blade is completed, the cathode tool 1 exits the blade channel, the overall blade disk mounting plate rotates one index, and the next blade blank 2 enters the processing area. The electrolytic shaping process is repeated until all blade blanks 2 on the entire blade disk are processed.

[0043] In some embodiments, for integral bladed disks of different models and with different allowance distributions, efficient shaping can be achieved by changing the structure of the cathode tool 1 surface, thereby improving the applicability.

[0044] The present invention also provides an electrolytic shaping processing device, such as... Figures 3-7 As shown, it includes: an electrolyte circulation system, a machine tool processing system, and a control system. The machine tool processing system includes a machine tool body, a machine tool connecting shaft 7, a cathode tool 1, and an integral bladed disk mounting plate. The cathode tool 1 is mounted on the machine tool body via the machine tool connecting shaft 7. The control system controls the machine tool body to drive the cathode tool 1 to insert into or retract from the blade cascade channel. The shape of the cathode tool 1 is designed according to the allowance distribution on the surface to be machined of the blade blank 2. The cathode tool 1 is used to efficiently homogenize and shape the rough-machined blade blank 2 to form a shaped blank.

[0045] The electrolytic shaping equipment provided in this embodiment of the invention is used to perform the overall bladed disk electrolytic machining process in the above embodiments. Therefore, this embodiment of the invention has all the advantages of the above embodiments, and will not be repeated here.

[0046] In some embodiments, the cathode tool 1 is mounted on the machine tool connecting shaft 7 via the mounting base 4, and the cathode tool 1 is detachably mounted on the mounting base 4.

[0047] This embodiment can perform efficient shaping processing on integral bladed disks of different models and with different allowance distributions by changing the structure of the cathode tool 1 surface.

[0048] In some embodiments, the mounting base 4 is connected to the base 6 by bolts or other fasteners, and the base 6 is mounted on the machine tool connecting shaft 7.

[0049] In some embodiments, the cathode tool 1 is a sheet electrode plate.

[0050] In summary, the process provided by the present application adds efficient overall blisk blade blank shaping machining based on non-equilibrium electrolytic machining rules to the original machining process. The cathode tool used in this special shaping machining process has a unique cathode design method. This cathode has a very high flattening ratio, which can achieve concentrated removal of the material at the large excess amount of the blank, while the material in the small excess amount area is less affected. This special process can complete the shaping work of the blade profile in the narrow blade channel and with a small machining feed amount, and has very high efficiency. This special process can efficiently reduce the excess amount difference of the blade blank after rough machining of the blade channel, and improve the excess amount distribution, which is beneficial to the next electrolytic finishing process.

[0051] The principles and implementation manners of the present application are described by using specific examples in the present application. The above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In summary, the content of the present application should not be understood as a limitation of the present application.

Claims

1. A bulk blade disc electrochemical machining process characterized by: The application relates to a method for machining a whole blade disc, comprising the following steps: electrolytic rough machining: machining blade blanks and blade channel from original blade disc blanks; electrolytic finishing machining: using a cathode tool to uniformly and efficiently finish the blade blanks after rough machining to form finished machining blanks; wherein the appearance of the cathode tool is designed according to the residual amount distribution of the surface of the blade blank to be machined; electrolytic finishing machining: machining the finished machining blanks into blades with accurate shapes and surfaces; the part of the cathode tool corresponding to the region with large residual amount on the surface to be machined is a convex structure, and the part corresponding to the region with small residual amount is a concave, insulating or hollow structure.

2. The blisk electrochemical machining process of claim 1, wherein: In the electrolytic finishing machining process, the machining parameters during machining are monitored in real time on a control panel, and the machining parameters include but are not limited to current density, electrolyte pressure, electrolyte flow, residual machining distance and feeding speed.

3. The blisk electrochemical machining process of claim 1, wherein: In the electrolytic finishing machining process, after the machining of one blade is completed, the cathode tool exits the blade channel, the whole blade disc mounting disc rotates by one index, the next blade blank enters the machining area, and the electrolytic finishing machining process is repeated until the machining of all the blade blanks on the whole blade disc is completed.

4. The blisk electrochemical machining process of claim 1, wherein: For different types and different residual amount distributions of the whole blade disc, efficient finishing machining can be carried out by changing the structure of the surface of the cathode tool.

5. An electrochemical contouring apparatus comprising: An electrolyte circulating system, a machine tool machining system and a control system, characterized in that: the machine tool machining system comprises a machine tool body, a machine tool connecting shaft, a cathode tool and a whole blade disc mounting disc, the cathode tool is installed on the machine tool body through the machine tool connecting shaft, the control system controls the machine tool body to drive the cathode tool to be inserted into or exit from the blade channel, the appearance of the cathode tool is designed according to the residual amount distribution of the surface of the blade blank to be machined; the cathode tool is used to uniformly and efficiently finish the blade blanks after rough machining to form finished machining blanks; the part of the cathode tool corresponding to the region with large residual amount on the surface to be machined is a convex structure, and the part corresponding to the region with small residual amount is a concave, insulating or hollow structure.

6. The electrochemical contouring apparatus of claim 5, wherein: The cathode tool is installed on the machine tool connecting shaft through a mounting seat, and the cathode tool can be detachably arranged on the mounting seat.

7. The electrochemical contouring apparatus of claim 5, wherein: The cathode tool is a sheet electrode plate.

Images