A multi-rigidity porous cathode mask electrolytic processing method and implementation device

Abstract

The present invention discloses a multi-rigidity porous cathode mask electrolytic machining method and implementation device, belonging to the field of electrolytic machining technology. It includes a base plate, a workpiece, a flexible fabric cathode, a liquid hose, a solenoid valve, a set screw, a liquid inlet cavity, a pipe joint, a liquid separation plate, a connecting plate, a liquid medium, a pulse power supply, a liquid collection cavity, a sleeve, a mask plate, and an adhesive tape. The method is characterized in that by simply replacing the liquid medium with rigid nickel foam or flexible sponge, rigid and flexible porous cathode mask electrolytic machining can be achieved on the same process device, meeting the high consistency machining requirements of the upper and lower surface textures of diversified surfaces and reducing the design and manufacturing costs of the process device; the pulse and vibration synchronization method is used to regulate the pulse power supply and electrolyte supply, so that the electrolyte forms a pulsed dynamic flow and the workpiece material undergoes intermittent dissolution, which is beneficial to suppressing the accumulation of electrolytic products and stray electric field corrosion in the gap area and improving the machining localization of the surface texture.

Description

Technical Field

[0001] The invention relates to a multi-rigidity multi-porous cathode mask electrolytic machining method and an implementation device, belonging to the technical field of electrolytic machining. Background Art

[0002] The preparation of micro-textures on the surface of parts can store lubricating media, reduce the wear of parts, and effectively improve the friction and wear performance of the surface of parts. Therefore, surface texturing is widely used in mechanical sealing, heat and mass transfer, and surface wetting. Common processing methods for surface texturing include electrospark machining, laser machining, electrolytic machining, etc. Among them, surface texturing by electrospark machining can achieve high precision, but the electrode loss is serious and there is a recast layer; although femtosecond laser overcomes the defects of traditional laser in causing thermal stress on the workpiece, it is expensive and has low efficiency in large-area processing; mask electrolytic machining is a cold processing method based on the principle of electrochemical anodic dissolution to achieve metal material removal. It has the advantages of no cathode loss, no stress, and no heat-affected zone. In addition, the mask covering the surface of the workpiece can be made into a hollow pattern with complex structure, which can achieve low-cost and high-efficiency processing of large-area micro-textures on the surface of metal parts.

[0003] Compared with the solid cathode or hollow cathode used in traditional mask electrolytic machining, the introduction of a rigid porous cathode with a large specific surface area and an interconnected microporous structure is conducive to uniformizing the electric field distribution, promoting uniform dissolution of materials, and obtaining high-precision surface textures. Existing rigid porous cathode mask electrolytic machining usually adopts a fixed cathode mode, and the electrolyte flow mode mostly adopts side flow, positive flow and jet flow. Among them, in side flow and positive flow machining, the electrolyte flow rate is low, and the heat and products generated by the machining are difficult to be discharged in time. In addition, in side flow machining, the electrolytic products accumulate along the process, causing the electrolyte conductivity to gradually decrease; while in positive flow machining, the electrolyte flow field distribution is relatively disordered, which is not conducive to the stable progress of the machining process. In jet machining, a high-pressure jet method is used to force the electrolyte into the machining area. It has the characteristics of fast electrolyte renewal speed and rapid product discharge, which is conducive to improving the machining depth and machining consistency of the surface texture. However, it should be noted that bubbles can escape through the pores of the porous cathode, while some insoluble products remain in the processing area and on the surface of the porous cathode, adversely affecting the current conductivity of the porous cathode. In addition, rigid porous cathodes are difficult to apply to the processing of surface textures on curved workpieces due to their poor shape adaptability.

[0004] Recent international research indicates that using flexible cathodes with excellent bending properties to match curved workpieces can achieve the machining of various upper and lower surface textures. However, due to the close contact between the flexible cathode and the mask, electrolyte renewal and electrolysis product removal within the machining area are extremely difficult. Insoluble electrolysis products are still prone to accumulating on the flexible cathode surface, hindering the improvement of surface texture consistency and machining localization.

[0005] At present, rigid porous cathodes can achieve highly localized processing of surface textures on planes and simple cylindrical surfaces, but the processing adaptability of rigid porous cathodes is poor, and it is difficult to meet the processing needs of surface textures on various curved workpieces. In addition, insoluble electrolytic products are easily left at the bottom of the cathode, affecting the current conduction performance of the processing area. Although flexible cathodes can match curved workpieces of different shapes, it is extremely difficult to discharge electrolytic products in the processing area. In addition, regardless of whether a rigid porous cathode or a flexible porous cathode is used, for the surface texture processing needs of different shapes, it is often necessary to equip multiple sets of special electrolytic processing process equipment. Not only is the design and manufacturing cost of the process equipment high, but the development cycle of the process technology is also long. Summary of the Invention

[0006] 1. In response to the shortcomings of existing mask electrolytic machining technology, the present invention proposes a multi-rigidity porous cathode mask electrolytic machining method and implementation device, which promotes the discharge of insoluble products in the machining area and the porous cathode surface, meets the high-consistency machining requirements of the upper and lower surface textures of diversified surfaces, and reduces the design and manufacturing costs of the process equipment.

[0007] 2. In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is: a multi-rigidity porous cathode mask electrolytic processing method, which uses a flexible fabric cathode wrapped with a liquid medium to perform mask electrolytic processing on the workpiece covered with a mask plate, and the flexible fabric cathode and the workpiece are respectively connected to the negative and positive poles of the power supply, thereby transmitting the electric field energy to the processing area; the electrolyte flow is controlled by adjusting the opening size of the solenoid valves on both sides of the liquid collection cavity, and the electrolyte inside the liquid medium is quantitatively supplemented; the liquid medium is replaced with rigid foam nickel or flexible sponge, and rigid and flexible porous cathode mask electrolytic processing modes can be realized respectively; when the rigid porous cathode mask electrolytic processing mode is adopted, the bottom end of the flexible fabric cathode wrapped with foam nickel sprays electrolyte, and the generated fluid dynamic pressure presses the mask plate tightly to the workpiece; when the flexible porous cathode mask electrolytic processing mode is adopted, the bottom end of the flexible fabric cathode wrapped with sponge permeates electrolyte, and the elastic deformation of the sponge is used to press the mask plate tightly to the workpiece.

[0008] The pulse power supply and electrolyte supply are regulated by the pulse and vibration synchronization method. The flexible fabric cathode coated with the liquid medium vibrates in a trapezoidal wave driven by the liquid inlet cavity. When the rigid porous cathode mask electrolytic processing mode is adopted, the flexible fabric cathode coated with foam nickel is non-contact with the mask plate. When the flexible fabric cathode moves to the bottom of the trapezoidal wave, the pulse power supply is turned on and the material is removed. When the flexible fabric cathode is away from the bottom of the trapezoidal wave, the pulse power supply is turned off and the electrolyte in the processing area is updated. When the flexible porous cathode mask electrolytic processing mode is adopted, the flexible fabric cathode coated with the sponge is tightly fitted with the mask plate. When the fabric cathode moves to the bottom of the trapezoidal wave and the sponge pressing force is large, the pulse power supply is turned on and the material is removed. When the flexible fabric cathode is away from the bottom of the trapezoidal wave and the sponge pressing force is reduced, the pulse power supply is turned off and no material is removed.

[0009] Another technical purpose of the present invention is to provide a device for realizing electrolytic machining of multi-rigidity porous cathode mask, comprising a base plate, a curved workpiece, a flexible fabric cathode, a liquid hose, an electromagnetic valve, a set screw, a liquid inlet cavity, a pipe joint, a liquid separation plate, a connecting plate, a liquid medium, a pulse power supply, a liquid collection cavity, a sleeve, a mask plate, and an adhesive tape; the upper end of the liquid inlet cavity is connected to the machine tool vibration device, threaded holes are provided on both sides, and the liquid inlet cavity and the connecting plate are fastened with set screws; a liquid collection cavity is provided below the connecting plate, and the liquid collection cavity Threaded holes are symmetrically provided on both sides of the body, and the liquid separation plate and the liquid medium are fixed to the inner wall of the liquid collection cavity by means of set screws; a sleeve is provided under the liquid collection cavity, and the inner wall of the sleeve fits the flexible fabric cathode, the inner side of the flexible fabric cathode tightly covers the liquid medium, and the upper end is pressed tightly against the sleeve and the end face of the liquid collection cavity, and the liquid collection cavity, the sleeve and the connecting plate are connected as a whole by means of set screws; a mask plate is provided under the flexible fabric cathode, and the mask plate is fixed to the surface of the workpiece by means of adhesive tape; the workpiece is fixedly connected to the base plate by set screws.

[0010] When the rigid porous cathode mask electrolytic machining mode is adopted, the liquid medium is rigid nickel foam with a pore density of 20-100PPI, an average pore diameter of 50-500μm, and a porosity of 30%-90%; when the flexible porous cathode mask electrolytic machining mode is adopted, the liquid medium is polyurethane sponge with a pore density of 20-100PPI and a porosity of 80%-96%.

[0011] The mask plate is made of polyimide material, and a hollow pattern is processed on the mask plate by a laser method.

[0012] 3. The beneficial effects of the present invention are: (1) The present invention can realize rigid and flexible porous cathode mask electrolytic processing on the same process device only by replacing the liquid medium with rigid nickel foam or flexible sponge, thereby meeting the high consistency processing requirements of the upper and lower surface textures of diversified surfaces and reducing the design and manufacturing costs of the process device; (2) The present invention adopts a pulse and vibration synchronization method to regulate the pulse power supply and electrolyte supply, so that the workpiece material is dissolved intermittently, which is beneficial to suppress the accumulation of electrolytic products in the gap area and stray electric field corrosion, and improve the processing localization of the surface texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a half-section schematic diagram of the overall structure of the device for electrolytic machining of multi-rigidity porous cathode masks according to the present invention.

[0014] Figure 2 Schematic diagram of the structure of the liquid separation plate of the present invention.

[0015] Figure 3 Schematic diagram of the liquid medium structure of the present invention.

[0016] In the figure: 1, base plate, 2, workpiece, 3, flexible fabric cathode, 4, liquid hose, 5, solenoid valve, 6, set screw, 7, liquid inlet cavity, 8, pipe joint, 9, liquid separation plate, 10, connecting plate, 11, liquid medium, 12, pulse power supply, 13, liquid collection cavity, 14, sleeve, 15, mask plate, 16, adhesive tape. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1The figure is a half-section diagram of the overall structure of the device for realizing electrolytic machining of multi-rigidity porous cathode masks, which includes: 1. base plate, 2. workpiece, 3. flexible fabric cathode, 4. liquid hose, 5. solenoid valve, 6. set screw, 7. liquid inlet cavity, 8. pipe joint, 9. liquid separator, 10. connecting plate, 11. liquid medium, 12. pulse power supply, 13. liquid collection cavity, 14. sleeve, 15. mask plate, 16. adhesive tape; the upper end of the liquid inlet cavity 7 is connected to the machine tool vibration device, and threaded holes are provided on both sides, and the liquid inlet cavity 7 is fastened to the connecting plate 10 by a set screw 6; the electrolyte flow rate is controlled by adjusting the opening size of the solenoid valve 5 on both sides of the liquid collection cavity 13, and the electrolyte inside the liquid medium 11 is adjusted. The liquid is quantitatively replenished; a liquid collection cavity 13 is provided below the connecting plate 10, and threaded holes are symmetrically provided on both sides of the liquid collection cavity 13, and the liquid separation plate 9 and the liquid medium 11 are fixed to the inner wall of the liquid collection cavity 13 by means of set screws 6; a sleeve 14 is provided below the liquid collection cavity 13, and the inner wall of the sleeve 14 fits the flexible fabric cathode 3, and the inner side of the flexible fabric cathode 3 tightly covers the liquid medium 11, and the upper end is pressed tightly against the sleeve 14 and the end face of the liquid collection cavity 13, and the liquid collection cavity 13, the sleeve 14 and the connecting plate 10 are connected as a whole by means of set screws 6; a mask plate 15 is provided below the flexible fabric cathode 3, and the mask plate 15 is fixed to the surface of the workpiece 2 by means of adhesive tape 16; the workpiece 2 is fixedly connected to the base plate 1 by means of set screws 6.

[0019] By replacing the liquid medium 11 with rigid nickel foam or flexible sponge, rigid and flexible porous cathode mask electrolytic processing modes can be realized respectively, and in the rigid and flexible porous cathode mask electrolytic processing processes, the pulse power supply 12 and the electrolyte supply are regulated by pulse and vibration synchronization. The flexible fabric cathode 3 coated with the liquid medium 11 vibrates in a trapezoidal wave under the drive of the liquid inlet cavity 7; when the rigid porous cathode mask electrolytic processing mode is adopted, the electrolyte is sprayed from the bottom end of the flexible fabric cathode 3 coated with nickel foam, and the mask plate 15 is pressed tightly against the workpiece 2 by means of fluid dynamic pressure. The flexible fabric cathode 3 coated with nickel foam is in non-contact with the mask plate 15. When the flexible fabric cathode 3 moves When it reaches the bottom of the trapezoidal wave, the pulse power supply 12 is turned on and material is removed. When the flexible fabric cathode 3 is away from the bottom of the trapezoidal wave, the pulse power supply 12 is turned off and the electrolyte in the processing area is updated. When the flexible porous cathode mask electrolytic processing mode is adopted, the bottom of the flexible fabric cathode 3 covered with sponge is infiltrated with electrolyte, and the elastic deformation of the sponge is used to press the mask plate 15 tightly against the surface of the workpiece 2. The flexible fabric cathode 3 covered with sponge is tightly fitted to the mask plate 15. When the flexible fabric cathode 3 moves to the bottom of the trapezoidal wave and the sponge pressing force is large, the pulse power supply 12 is turned on and material is removed. When the flexible fabric cathode 3 is away from the bottom of the trapezoidal wave and the sponge pressing force is reduced, the pulse power supply 12 is turned off and no material is removed.

[0020] Figure 2Schematic diagram of the liquid separator plate structure. An evenly distributed array of through holes is provided inside the liquid separator plate 9, so that the electrolyte flows evenly from the liquid inlet cavity 7 into the liquid collection cavity 13 and the liquid medium 11, and limits the vertical displacement of the liquid medium 11.

[0021] Figure 3 This is a schematic diagram of the liquid medium structure. By replacing the liquid medium 11 with rigid nickel foam or flexible sponge as the electrolyte flow channel, a rigid or flexible porous cathode mask electrolytic processing mode can be achieved. The rigid nickel foam and the flexible sponge both have interconnected microporous structures.

[0022] The present invention has many specific application paths. The above is only the preferred implementation method of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technology and rights protection of the present invention.

Claims

1. A method for electrolytic machining of multi-rigidity porous cathode masks, characterized in that: A flexible fabric cathode (3) wrapped with a liquid medium is used to perform mask electrolytic processing on a workpiece (2) covered with a mask plate (15), and the flexible fabric cathode (3) and the workpiece (2) are respectively connected to the negative electrode and the positive electrode of the power supply, thereby transmitting the electric field energy to the processing area; the electrolyte flow rate is controlled by adjusting the opening size of the electromagnetic valve (5) on both sides of the liquid collection cavity (13), and the electrolyte inside the liquid medium (11) is quantitatively supplemented; the liquid medium (11) is replaced with rigid foam nickel or flexible seawater. The invention can realize rigid and flexible porous cathode mask electrolytic processing modes respectively; when the rigid porous cathode mask electrolytic processing mode is adopted, the bottom end of the flexible fabric cathode (3) coated with foam nickel sprays electrolyte, and the generated fluid dynamic pressure presses the mask plate (15) tightly to the workpiece (2); when the flexible porous cathode mask electrolytic processing mode is adopted, the bottom end of the flexible fabric cathode (3) coated with sponge permeates electrolyte, and the elastic deformation of the sponge is used to press the mask plate (15) tightly to the workpiece (2); The pulse power supply (12) and the electrolyte supply are regulated by using a pulse and vibration synchronization method, and the flexible fabric cathode (3) coated with the liquid medium (11) vibrates in a trapezoidal wave under the drive of the liquid inlet cavity (7); when the rigid porous cathode mask electrolytic processing mode is adopted, the flexible fabric cathode (3) coated with the foam nickel is in non-contact with the mask plate (15), and when the flexible fabric cathode (3) moves to the bottom of the trapezoidal wave, the pulse power supply (12) is turned on and material is removed, and when the flexible fabric cathode (3) is far away, the flexible fabric cathode (3) is turned on and material is removed. When the flexible fabric cathode (3) moves to the bottom of the trapezoidal wave and the sponge pressing force is large, the pulse power supply (12) is turned on and the material is removed. When the flexible fabric cathode (3) moves away from the bottom of the trapezoidal wave and the sponge pressing force decreases, the pulse power supply (12) is turned off and the material is not removed.

2. The device for implementing the multi-rigidity porous cathode mask electrolytic machining method according to claim 1 comprises a base plate (1), a workpiece (2), a flexible fabric cathode (3), a liquid hose (4), a solenoid valve (5), a set screw (6), a liquid inlet cavity (7), a pipe joint (8), a liquid separation plate (9), a connecting plate (10), a liquid medium (11), a pulse power supply (12), a liquid collection cavity (13), a sleeve (14), a mask plate (15), and an adhesive tape (16), characterized in that: The upper end of the liquid inlet cavity (7) is connected to the machine tool vibration device, and threaded holes are provided on both sides. The liquid inlet cavity (7) is fastened to the connecting plate (10) by a set screw (6); a liquid collection cavity (13) is provided below the connecting plate (10), and threaded holes are symmetrically provided on both sides of the liquid collection cavity (13). The liquid separation plate (9) and the liquid medium (11) are fixed to the inner wall of the liquid collection cavity (13) by the set screw (6); a sleeve (14) is provided below the liquid collection cavity (13), and the inner wall of the sleeve (14) is in contact with the flexible fabric inner wall. The flexible fabric cathode (3) is tightly covered with a liquid medium (11) on the inner side, and the upper end is pressed against the sleeve (14) and the end face of the liquid collecting cavity (13); the liquid collecting cavity (13), the sleeve (14) and the connecting plate (10) are connected as a whole through a set screw (6); a mask plate (15) is provided below the flexible fabric cathode (3), and an adhesive tape (16) is used to fix the mask plate (15) to the surface of the workpiece (2); and the workpiece (2) is fixedly connected to the base plate (1) through the set screw (6).

3. The device for implementing the multi-rigidity porous cathode mask electrolytic machining method according to claim 2, characterized in that: When the rigid porous cathode mask electrolytic processing mode is adopted, the liquid medium (11) is a rigid nickel foam with a pore density of 20-100 PPI, an average pore diameter of 50-500 μm, and a porosity of 30%-90%; when the flexible porous cathode mask electrolytic processing mode is adopted, the liquid medium (11) is a polyurethane sponge with a pore density of 20-100 PPI and a porosity of 80%-96%.

4. The device for implementing the multi-rigidity porous cathode mask electrolytic machining method according to claim 2, characterized in that: The mask plate (15) is made of polyimide material, and a hollow pattern is processed on the mask plate (15) by means of a laser method.

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