Electrochemical machining device, electrochemical machining method, and aircraft engine

Abstract

The application discloses an electrolytic machining device, an electrolytic machining method and an aero-engine, which are used for fixing a case on an electrolytic machining equipment. The electrolytic machining equipment comprises a main shaft chuck, a cathode and a lathe rotating shaft. The electrolytic machining device comprises a positioning plate, which is used for being installed on the lathe rotating shaft to serve as a positioning reference and a mounting base; a fixing member, which is used for tightly fixing a small end of the case on the positioning plate to axially and radially position the case on the lathe rotating shaft; and a sealing member, which is used for being connected with the fixing member and sealed to an inner wall of a large end of the case. The case does not need to be dismounted from the lathe rotating shaft, and can be directly measured on the lathe, so that the machining allowance can be quickly determined, the remaining machining time can be determined, the clamping operation time is saved, and the machining efficiency is greatly improved. The case does not need to be dismounted, and the machining error and the measurement error caused by secondary clamping can be prevented, and the machining consistency and the machining precision are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of electrochemical machining, and in particular, to an electrochemical machining apparatus, an electrochemical machining method, and an aero-engine. Background Technology

[0002] The casing is one of the key components of an aero-engine. To reduce its weight, a thin-walled structure is often used. In addition, the casing is often made of difficult-to-machine materials such as high-temperature alloys, which poses a significant challenge to traditional machining techniques. Turning is prone to deformation during machining, roundness is difficult to guarantee, tool wear is severe, costs are high, and machining efficiency is low, resulting in obvious drawbacks.

[0003] Electrolytic machining, based on the principle of electrochemical anodic dissolution, can remove material from the casing surface using a simple-shaped cathode, thus achieving surface removal. This method avoids contact between the cathode and casing during processing, eliminating contact stress. Furthermore, only a reduction reaction occurs at the cathode, releasing hydrogen gas, resulting in no material loss and high processing efficiency, making it ideal for casing surface removal. Currently, a common method involves fixing the cathode while the casing rotates continuously. Under electrochemical action, the casing surface material is continuously dissolved. However, the tooling used in this method cannot achieve online measurement; the casing needs to be periodically removed to measure the wall thickness and determine the remaining machining allowance or processing time to avoid over-cutting. This frequent disassembly of the casing easily leads to secondary clamping errors and significantly reduces production efficiency. Summary of the Invention

[0004] This invention provides an electrolytic machining apparatus, an electrolytic machining method, and an aero-engine to solve the technical problem in the prior art where the frequent disassembly of the casing during casing electrolytic machining leads to clamping errors and low machining efficiency.

[0005] The technical solution adopted in this invention is as follows:

[0006] An electrochemical machining apparatus is used to fix a machine casing to an electrochemical machining equipment, the electrochemical machining equipment including a spindle chuck, a cathode, and a machine tool spindle, the electrochemical machining apparatus comprising:

[0007] A positioning plate is used to be installed on the machine tool spindle as a positioning reference and mounting base;

[0008] A fastener is used to press and fix the small end of the housing onto the positioning plate so that the housing is axially and radially positioned on the machine tool spindle.

[0009] A seal is used to connect with the fastener and seal the inner wall of the large end of the casing.

[0010] As a further improvement to the above technical solution, the positioning plate has a stepped structure for engaging with the small end face of the casing. The stepped structure is annular, and the annular surface of the stepped structure matches the inner annular surface of the small end of the casing to radially position the casing.

[0011] As a further improvement to the above technical solution, the height of the step structure is less than the thickness of the small end face of the casing.

[0012] As a further improvement to the above technical solution, an insulating sleeve is provided on the outer wall of the positioning plate. The insulating sleeve is used to fit onto the positioning plate, and the two ends of the insulating sleeve respectively abut against the small end of the machine tool spindle and the machine casing to isolate the electrolyte from the positioning plate during electrolytic machining.

[0013] As a further improvement to the above technical solution, the outer diameter of the fastener is larger than the diameter of the inner ring surface of the small end of the casing and smaller than the diameter of the inner wall of the casing; the fastener is used to press against the inner end surface of the small end of the casing and to connect with the fastener.

[0014] As a further improvement to the above technical solution, the seal includes a connecting section and a sealing section distributed along the axial direction, the height of the seal matches the height of the casing, and the sealing section has an oblique outer circular surface for matching the inner wall of the large end of the casing.

[0015] As a further improvement to the above technical solution, the spindle chuck and the cathode are respectively provided with internal channels for the electrolyte to pass through; the machining edge of the cathode is provided with an outlet groove, and the width, spacing and number of the outlet grooves are optimized according to the results of flow field simulation.

[0016] As a further improvement to the above technical solution, the spindle chuck, the cathode, and the positioning plate are all made of stainless steel; the fixing component and the sealing component are all made of insulating material.

[0017] According to another aspect of the present invention, an electrochemical machining method is also provided, which utilizes any of the electrochemical machining apparatuses described above, the machining method comprising:

[0018] S1. The positioning plate is connected to the machine tool spindle and aligned to ensure that the positioning plate is concentric with the machine tool spindle;

[0019] S2. Position the small end of the casing on the positioning plate and press it firmly with the fastener;

[0020] S3. Install the seal onto the fastener to seal the large end of the casing;

[0021] S4. Set the processing parameters and turn on the processing power to start electrolytic processing;

[0022] S5. After the stage processing is completed, cut the processing power supply, move the cathode away from the casing, and remove the seals to expose the inner and outer walls of the casing.

[0023] S6. Measure the wall thickness of the casing using a thickness gauge, and determine the processing time for the next stage based on the wall thickness;

[0024] S7. Install the seals and repeat steps S4-S6 until the wall thickness meets the requirements.

[0025] According to another aspect of the present invention, an aero-engine is also provided, including a casing, wherein the electrolytic machining method described above is applied.

[0026] This invention has the following advantages: The electrolytic machining apparatus uses a positioning plate mounted on the machine tool spindle as a positioning reference and mounting base. The positioning plate is concentric with the machine casing, positioning the small end of the casing on the positioning plate, which is concentric with the positioning plate and thus with the machine tool spindle. A fixing component presses the small end of the casing to secure it. A sealing component connects to the fixing component, simultaneously sealing the inner wall of the large end of the casing, thus completing the installation and sealing of the casing. Electrolytic machining of the casing can then begin. After stage machining, removing the sealing component and removing the cathode completely exposes both the inner and outer walls of the casing. The two probes of the thickness gauge can then extend from the large end of the casing towards the small end to measure the wall thickness without disassembling the casing from the machine tool spindle. Measurements can be performed directly on the machine tool, quickly determining the machining allowance and remaining machining time, saving clamping time and significantly improving machining efficiency. Simultaneously, the elimination of the need to disassemble the casing prevents machining and measurement errors caused by secondary clamping, greatly improving machining consistency and accuracy.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a cross-sectional view of the electrolytic processing apparatus according to a preferred embodiment of the present invention;

[0030] Figure 2 yes Figure 1 Enlarged view of a portion at point A;

[0031] Figure 3 This is a schematic diagram of thickness measurement using an electrolytic machining apparatus according to a preferred embodiment of the present invention;

[0032] Figure 4 yes Figure 3A magnified view of section B;

[0033] Figure 5 This is a schematic diagram of the cathode structure of a preferred embodiment of the present invention;

[0034] 1. Spindle chuck 2. Cathode 3. Casing 4. Seal 5. Fixing component 6. Insulating sleeve 7. Positioning plate 8. Machine tool spindle 9. Machining blade 10. Machining clearance 11. Liquid outlet trough 12. Thickness gauge. Detailed Implementation

[0035] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Reference Figures 1 to 5 A preferred embodiment of the present invention provides an electrolytic machining apparatus for fixing a housing 3 to an electrolytic machining equipment. The electrolytic machining equipment includes a spindle chuck 1, a cathode 2, and a machine tool spindle 8. The electrolytic machining apparatus includes:

[0037] Positioning plate 7 is used to be installed on machine tool spindle 8 as a positioning reference and mounting base;

[0038] The fastener 5 is used to press and fix the small end of the housing 3 onto the positioning plate 7 so that the housing 3 is axially and radially positioned on the machine tool spindle 8; in this embodiment, the fastener 5 is a circular pressure plate.

[0039] Seal 4 is used to connect with fastener 5 and seal the inner wall of the large end of casing 3.

[0040] Understandably, this electrolytic machining apparatus uses a positioning plate 7 mounted on the machine tool spindle 8 as a positioning reference and mounting base. The positioning plate 7 is concentric with the housing 3, positioning the small end of the housing 3 on the positioning plate 7, which is concentric with the positioning plate 7 and, consequently, with the machine tool spindle 8. The small end of the housing 3 is pressed by the fixing member 5 to fix the housing 3. The sealing member 4 connects with the fixing member 5 to seal the inner wall of the large end of the housing 3, thus completing the installation and sealing of the housing 3. Electrolytic machining of the housing 3 can then begin for staged processing. Afterwards, removing the seal 4 and the cathode 2 will completely expose the inner and outer walls of the housing 3. The two probes of the thickness gauge 12 can then be inserted from the large end to the small end of the housing 3 to measure the wall thickness. There is no need to remove the housing 3 from the machine tool spindle 8. The measurement can be performed directly on the machine tool, quickly determining the machining allowance and remaining machining time, saving clamping operation time, and greatly improving machining efficiency. At the same time, since there is no need to remove the housing 3, machining and measurement errors caused by secondary clamping can be prevented, greatly improving machining consistency and machining accuracy.

[0041] In this embodiment, the positioning plate 7 has a stepped structure for engaging with the small end face of the casing 3. The stepped structure is annular, and the annular surface of the stepped structure matches the inner annular surface of the small end of the casing 3 to radially position the casing 3. At the same time, the small end of the casing 3 abuts against the end face of the stepped structure to achieve axial positioning. The small end of the casing 3 is pressed against the stepped structure by the fastener 5 and the positioning plate 7 to achieve axial fixation.

[0042] The fastener 5 and the positioning plate 7 are connected by screws. The height of the step structure is slightly less than the thickness of the small end face of the casing 3, so that the force of the fastener 5 acts on the small end face of the casing 3, making the fixation stable.

[0043] In this embodiment, an insulating sleeve 6 is provided on the outer wall of the positioning plate 7. The insulating sleeve 6 is used to fit on the positioning plate 7, and the two ends of the insulating sleeve 6 respectively abut against the small ends of the machine tool spindle 8 and the machine casing 3 to isolate the electrolyte from the positioning plate 7 during electrolytic machining.

[0044] Furthermore, the sum of the thickness of the insulating sleeve 6 and the width of the stepped structure matches the width of the small end face of the casing 3.

[0045] In this embodiment, the outer diameter of the fastener 5 is greater than the diameter of the inner ring surface of the small end of the casing 3 and less than the diameter of the inner wall of the casing 3; the fastener 5 is used to press against the inner end surface of the small end of the casing 3 and to connect with the fastener 5.

[0046] In this embodiment, the sealing element 4 includes a cylindrical connecting section and a disc-shaped sealing section distributed along the axial direction. The height of the sealing element 4 matches the height of the casing 3. The sealing section has an oblique outer circular surface for matching the inner wall of the large end of the casing 3. The taper of the outer circular surface matches the taper of the inner wall of the casing 3 so that the sealing section and the inner wall of the casing 3 are interference-fitted to ensure the sealing effect.

[0047] Specifically, the machine tool spindle has threaded holes for installation and connection. In this embodiment, the positioning plate 7 has countersunk holes corresponding to the threaded holes of the machine tool, so as to be connected by screws or the like without interfering with the pressure plate. The positioning plate 7 has threaded holes, and the fixing member 5 has countersunk holes corresponding to the threaded holes of the positioning plate 7, so as to fix the fixing member 5 to the positioning plate 7 by screws without interfering with the sealing member 4. The fixing member 5 has threaded holes, and the sealing member 4 has through holes or countersunk holes corresponding to the threaded holes of the fixing member 5, so as to connect the sealing member 4 to the fixing member 5 by screws.

[0048] In this embodiment, the spindle chuck 1 and the cathode 2 are respectively provided with internal channels for the electrolyte to pass through; after the cathode 2 is installed on the spindle chuck 1, the internal channels of the two are connected; a liquid outlet groove 11 is opened on one end of the cathode 2 located at the machining edge 9. The liquid outlet groove 11 is strip-shaped and arranged in an array of multiple grooves. The groove width, groove spacing and number of the liquid outlet groove 11 are optimized by using the results of flow field simulation to improve the machining effect and machining efficiency.

[0049] In this embodiment, the spindle chuck 1, cathode 2, and positioning plate 7 are all made of stainless steel to ensure rigidity, meet the positioning accuracy requirements, and serve as a conductive medium; the fixing part 5 and the sealing part 4 are all made of insulating materials such as POM to meet rigidity requirements while preventing stray corrosion on themselves and the workpiece surface.

[0050] On the other hand, this embodiment also provides an electrolytic machining method, which uses the above-mentioned electrolytic machining apparatus. This machining method includes:

[0051] S1. The positioning plate 7 is connected to the machine tool spindle 8 and is aligned to make the positioning plate 7 concentric with the machine tool spindle 8;

[0052] Specifically, the positioning plate 7 is connected to the machine tool spindle 8 by screws. The outer diameter of the positioning plate 7 is aligned by dial indicator, and then the screws are tightened to ensure the concentricity of the positioning plate 7 and the machine tool spindle 8.

[0053] S2. Position the small end of the casing 3 on the positioning plate 7 and press it firmly with the fastener 5;

[0054] Specifically, the inner circle of the small end of the casing 3 is fitted onto the outer ring surface of the stepped structure of the positioning plate 7 and abuts against the end face of the stepped structure. The fastener 5 presses the casing 3 and locks it in place with screws.

[0055] S3. Install the seal 4 onto the fastener 5 to seal the large end of the housing 3;

[0056] Specifically, after the seal 4 extends into the housing 3, the oblique outer circular surface of its sealing section abuts against the inner wall of the large end of the housing 3 to seal. The seal 4 is locked and fixed to the fixing part 5 by screws so that it fits tightly with the housing 3 to ensure the sealing effect.

[0057] S4. Set the processing parameters and turn on the processing power to start electrolytic processing;

[0058] It is understandable that before any of steps S1-S4, the cathode 2 is connected to the spindle chuck 1 to make the internal channel of the spindle chuck 1 and the cathode 2 connected, and the spindle chuck 1 is connected to the machine tool spindle.

[0059] In step S4, the machine tool spindle 8 is connected to the positive terminal of the machining power supply, so that the housing 3 is positively charged, and the spindle chuck 1 is connected to the negative terminal of the machine tool machining power supply, so that the cathode 2 is negatively charged; the machine tool's liquid inlet pipe is connected to the internal channel of the spindle chuck 1 and then to the internal channel of the cathode 2. The electrolyte enters from the spindle chuck 1, flows through the internal channel of the spindle chuck 1 and the internal channel of the cathode 2 to the liquid outlet 11 of the cathode 2, flushes the machining gap 10 between the cathode 2 and the housing 3, provides the necessary conditions for the electrochemical reaction to occur, and carries away the electrolysis products and heat with the flow of electrolyte;

[0060] S5. After the stage processing is completed, cut the processing power supply, move the cathode 2 away from the casing 3, and remove the seal 4 to expose the inner and outer walls of the casing 3.

[0061] Specifically, after the first stage of processing is completed, the processing power supply and electrolyte delivery system are cut off, the machine tool spindle is raised to move the cathode 2 away from the housing 3, and then the cover plate is removed to expose the inner and outer surfaces of the housing 3.

[0062] S6. Measure the wall thickness of the casing 3 using the thickness gauge 12, and determine the processing time for the next stage based on the wall thickness;

[0063] Specifically, the two probes of the measuring instrument are respectively contacted with the inner and outer walls of the housing 3 and inserted from the large end of the housing 3 into the small end of the housing 3 to measure the wall thickness. The remaining processing time is determined based on the measured wall thickness value.

[0064] S7. Install seal 4, i.e. reinstall seal 4, and repeat steps S4-S6 until the wall thickness meets the requirements.

[0065] It is evident that this processing method enables online measurement of the wall thickness of the casing 3 without disassembling the casing 3, avoiding secondary clamping errors caused by frequent clamping of the casing 3, improving processing consistency and accuracy, quickly determining the processing allowance and remaining processing time, eliminating the need for frequent disassembly and clamping of the casing 3, and improving production efficiency.

[0066] On the other hand, this embodiment also provides an aero engine, including a casing, which is processed by the above-described electrolytic machining method.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrolytic machining apparatus for fixing a housing (3) to an electrolytic machining equipment, the electrolytic machining equipment comprising a spindle chuck (1), a cathode (2), and a machine tool spindle (8), characterized in that, The electrolytic processing apparatus includes: Positioning plate (7) is used to be installed on the machine tool spindle (8) as a positioning reference and mounting base; The fastener (5) is used to press and fix the small end of the housing (3) onto the positioning plate (7) so that the housing (3) is axially and radially positioned on the machine tool spindle (8); A sealing element (4) is used to connect with the fixing element (5) and seal the inner wall of the large end of the housing (3); the sealing element (4) includes a connecting section and a sealing section distributed along the axial direction, the height of the sealing element (4) matches the height of the housing (3), and the sealing section has an oblique outer circular surface for matching the inner wall of the large end of the housing (3); the sealing element (4) is used to be removed after stage processing and cooperate with the cathode withdrawal action to completely expose the inner and outer walls of the housing (3) so that the two probes of the thickness gauge (12) can extend from the large end of the housing (3) to the small end for wall thickness measurement.

2. The electrolytic processing apparatus according to claim 1, characterized in that, The positioning plate (7) has a stepped structure for engaging with the small end face of the casing (3). The stepped structure is annular, and the annular surface of the stepped structure matches the inner annular surface of the small end of the casing (3) to radially position the casing (3).

3. The electrolytic processing apparatus according to claim 2, characterized in that, The height of the stepped structure is less than the thickness of the small end face of the casing (3).

4. The electrolytic processing apparatus according to claim 2, characterized in that, An insulating sleeve (6) is provided on the outer wall of the positioning plate (7). The insulating sleeve (6) is used to fit on the positioning plate (7), and the two ends of the insulating sleeve (6) respectively abut against the small end of the machine tool spindle (8) and the machine casing (3) to isolate the electrolyte from the positioning plate (7) during electrolytic machining.

5. The electrolytic processing apparatus according to claim 1, characterized in that, The outer diameter of the fastener (5) is greater than the diameter of the inner ring surface of the small end of the casing (3) and less than the diameter of the inner wall of the casing (3); the fastener (5) is used to press against the inner end face of the small end of the casing (3) and to connect with the fastener (5).

6. The electrolytic processing apparatus according to claim 1, characterized in that, The spindle chuck (1) and the cathode (2) are respectively provided with internal channels for the electrolyte to pass through; the machining edge (9) end of the cathode (2) is provided with a liquid outlet groove (11), and the groove width, groove spacing and number of the liquid outlet groove (11) are optimized according to the results of flow field simulation.

7. The electrolytic processing apparatus according to claim 1, characterized in that, The spindle chuck (1), the cathode (2) and the positioning plate (7) are all made of stainless steel; the fixing part (5) and the sealing part (4) are all made of insulating material.

8. An electrolytic machining method, characterized in that, The processing method, using the electrolytic processing apparatus as described in any one of claims 1-7, comprises: S1. The positioning plate is connected to the machine tool spindle and aligned to ensure that the positioning plate is concentric with the machine tool spindle; S2. Position the small end of the casing on the positioning plate and press it firmly with the fastener; S3. Install the seal onto the fastener to seal the large end of the casing; S4. Set the processing parameters and turn on the processing power to start electrolytic processing; S5. After the stage processing is completed, cut the processing power supply, move the cathode away from the casing, and remove the seals to expose the inner and outer walls of the casing. S6. Measure the wall thickness of the casing using a thickness gauge, and determine the processing time for the next stage based on the wall thickness; S7. Install the seals and repeat steps S4-S6 until the wall thickness meets the requirements.

9. An aircraft engine, characterized in that, Includes a casing, wherein the casing is subjected to the electrolytic machining method as described in claim 8.

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