A cathode local insulation device for electrochemical machining

Abstract

This invention relates to the field of electrochemical machining technology and discloses a cathode partial insulation device for electrochemical machining. It includes a cathode body and an adjustable insulating cover structure. The working surface of the cathode body has multiple mounting slots, each with a snap-fit ​​part. Multiple insulating modules are detachably mechanically connected to the mounting slots via snap-fit ​​connections, allowing the insulating modules to be independently disassembled and replaced according to machining requirements. In a second embodiment, a flexible insulating film is attached to the working surface of the cathode body. The flexible insulating film has weakening lines dividing it into multiple zones, and each zone has a traction tag at its edge. During machining, the traction tag is pulled along the weakening lines to gradually remove each zone. This invention solves the problem that existing electrochemical machining cathode insulation layers cannot be configured and dynamically adjusted in three dimensions according to the requirements of complex twisted surfaces, and is suitable for electrochemical machining of complex surface workpieces such as integral bladed disks of aircraft engines.

Description

Technical Field

[0001] This invention relates to the field of electrolytic machining technology, and more specifically, to a cathode local insulation device for electrolytic machining. Background Technology

[0002] Electrolytic machining is a special machining method that uses the principle of anodic dissolution of metal in an electrolyte to shape workpieces. During electrolytic machining, the cathode acts as the tool electrode, and its surface shape determines the workpiece's forming contour. To control the electrolytic reaction to occur only in specific areas, an insulating layer is usually applied to the non-machined areas of the cathode surface, preventing these areas from participating in the electrolytic reaction.

[0003] In existing technologies, the insulating layer on the cathode surface is usually formed by integral spraying or dip coating processes, and the coating is fixedly bonded to the cathode substrate. When the workpiece being processed is a workpiece with a complex torsional profile, such as an integral bladed disk blade of an aircraft engine, the torsion angle of the blade profile changes continuously from the blade root to the blade tip, and the distribution requirements of the cathode insulation area are different at different cross-sectional locations.

[0004] The insulation layer formed by integral coating has the following shortcomings: First, once the insulation layer is formed, it cannot be adjusted. When it is necessary to change the distribution of the insulation area during processing, the entire cathode must be replaced or recoated, resulting in reduced processing efficiency. Second, integral coating is difficult to form an insulation distribution that meets the differentiated requirements of each cross section on a three-dimensional curved surface, resulting in uneven processing allowance. Third, the boundary accuracy of the coating process is limited. During the spraying process, the splashing and flowing of the paint creates a gradual transition zone in the boundary area, making it difficult to form a clear dividing line. In situations where precise control of the insulation boundary is required, it is difficult to meet the surface accuracy requirements. Summary of the Invention

[0005] This invention provides a cathode local insulation device for electrolytic machining, which solves the technical problem that the existing electrolytic machining cathode insulation layer cannot be configured and dynamically adjusted in three dimensions according to the requirements of complex tortuous surfaces.

[0006] This invention discloses a cathode partial insulation device for electrolytic machining, comprising: a cathode body made of conductive material, the cathode body having a three-dimensional curved surface shape on its working surface, and a plurality of mounting slots distributed along the curved contour of the working surface; a plurality of detachable insulation units, each of the detachable insulation units comprising an insulator and a detachable connecting structure, the insulator being made of insulating material, and the detachable connecting structure being disposed on the side of the insulator facing away from the working surface; wherein, the inner wall of the mounting slot is provided with a mating part that cooperates with the detachable connecting structure, the detachable connecting structure and the mating part forming a detachable mechanical connection, allowing the detachable insulation unit to be independently installed in or removed from the mounting slot.

[0007] Furthermore, the detachable connection structure is a snap-fit ​​connection part, and the mating part is a snap-fit ​​mating part; the snap-fit ​​mating part is an annular groove arranged circumferentially along the inner wall of the mounting slot, and the snap-fit ​​connection part is an elastic claw arranged circumferentially along the back side of the insulator. The elastic claw undergoes elastic deformation during insertion and is engaged in the annular groove to form a locking fit.

[0008] Furthermore, the cathode body is provided with a positioning pin hole, and the detachable insulating unit is provided with a positioning pin corresponding to the positioning pin hole. The positioning pin is integrally formed with the insulator and protrudes outward from the back of the insulator. During installation, the positioning pin is inserted into the positioning pin hole to form a positioning fit.

[0009] Furthermore, the outer surface of the insulator is provided with a sealing lip, which extends circumferentially along the insulator. When the detachable insulating unit is installed in place, the sealing lip fits tightly against the opening edge of the mounting slot.

[0010] Furthermore, it also includes a conductive filler, which is a conductive block that matches the shape of the mounting slot. Its structure is the same as that of the detachable insulating unit, and it is also provided with a detachable connection structure and a positioning pin. It is fixed in the mounting slot through the detachable connection structure. The outer surface of the conductive filler is flush with the working surface of the cathode body, and the conductive filler and the cathode body form an electrical connection.

[0011] This invention also discloses a cathode partial insulation device for electrolytic processing, comprising: a cathode body made of conductive material, the cathode body having a three-dimensional curved surface shape on its working surface; a flexible insulating film comprising a film substrate, weakening lines, traction tags, and an adhesive layer; the film substrate being made of flexible insulating material and capable of conforming to the three-dimensional curved working surface of the cathode body through bending deformation; the weakening lines being local thinning structures disposed on the film substrate along a preset path, the weakening lines dividing the film substrate into multiple independent partitions; the traction tags being strip-shaped portions extending outward from the edges of each partition; the adhesive layer being located on the side of the film substrate facing away from the working surface, the adhesive layer being formed using a peelable adhesive material; wherein, when a tearing force is applied along the weakening lines, the film substrate breaks and separates along the weakening lines, separating adjacent partitions and allowing them to be peeled off from the surface of the cathode body.

[0012] Furthermore, the weakening lines are formed by laser scribing. The laser scans the surface of the membrane substrate along a preset path, causing the membrane substrate to locally vaporize along the laser path to form a groove-shaped thinning structure.

[0013] Furthermore, guide reinforcement strips are provided on both sides of the weakening line. The guide reinforcement strips are locally thickened areas that extend parallel to both sides of the weakening line. The strength of the guide reinforcement strips is higher than that at the weakening line. When a tearing force is applied, the tear develops along the weakening line.

[0014] Furthermore, the membrane substrate is provided with positioning marks, and the working surface of the cathode body is provided with positioning references corresponding to the positioning marks. During attachment, the positioning marks are aligned with the positioning references to ensure the attachment position of the flexible insulating film on the surface of the cathode body.

[0015] Furthermore, each of the partitions is provided with a region identifier, which is formed on the outer surface of the membrane substrate and is used to indicate the processing stage number corresponding to the partition; the outer surface of the membrane substrate is also provided with a corrosion-resistant coating, which covers the side of the membrane substrate facing the electrolyte.

[0016] The cathode local insulation device for electrolytic machining provided by the present invention solves the technical problem that the existing electrolytic machining cathode insulation layer cannot be configured and dynamically adjusted in three dimensions according to the requirements of complex tortuous surfaces.

[0017] When a modular, detachable insulation coating structure is adopted, the detachable insulation unit and the cathode body are connected by a detachable connection structure and mating parts to form a detachable mechanical connection. Each detachable insulation unit can be disassembled and assembled independently, so the distribution of the insulation area can be flexibly configured according to processing requirements. Since the installation slots are distributed along the three-dimensional curved working surface of the cathode body, the insulation area is configured in three-dimensional space. Since the insulation unit can be disassembled, replaced or recombined during processing intervals, it has the ability to dynamically adjust the insulation area in stages.

[0018] When using a flexible insulating film partitioned bonding structure, the weakening lines are pre-formed on the film substrate, and the position of the insulation boundary is precisely defined by the weakening lines, overcoming the problem of blurred boundaries in the spraying process. Because the film substrate is flexible, it can be bent and deformed to fit the three-dimensional curved surface of the cathode body. Because the flexible insulating film is divided into multiple independent partitions by the weakening lines, each partition can be peeled off one by one by pulling the label, which has the ability to adjust the insulation area in stages during the processing. Because the adhesive layer is formed by a peelable adhesive material, the adhesive layer is completely peeled off from the cathode surface without residue when peeled off, and the newly exposed cathode surface remains clean and conductive. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the cathode local insulation device for electrolytic machining according to Embodiment 1. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the cathode local insulation device for electrolytic machining according to Embodiment 1. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the cathode local insulation device for electrolytic machining according to Embodiment 1. Figure 3 ; Figure 4 This is a cross-sectional view of the cathode local insulation device for electrolytic machining according to Embodiment 1; Figure 5 This is a schematic diagram of the cathode local insulation device for electrolytic machining according to Embodiment 2; Detailed Implementation

[0020] Implementation Method 1: Electrolytic machining is a special machining method that uses the principle of anodic dissolution of metal in an electrolyte to shape workpieces. During electrolytic machining, the cathode acts as the tool electrode, and its surface shape determines the workpiece's forming contour. To control the electrolytic reaction to occur only in specific areas, an insulating layer is usually applied to the non-machined areas of the cathode surface, preventing these areas from participating in the electrolytic reaction.

[0021] In existing technologies, the insulating layer on the cathode surface is usually formed by integral spraying or dip coating processes, and the coating is fixedly bonded to the cathode substrate. When the workpiece being processed is a workpiece with a complex torsional profile, such as an integral bladed disk blade of an aircraft engine, the torsion angle of the blade profile changes continuously from the blade root to the blade tip, and the distribution requirements of the cathode insulation area are different at different cross-sectional locations.

[0022] The insulation layer formed by integral coating has the following shortcomings: First, once the insulation layer is formed, it cannot be adjusted. When it is necessary to change the distribution of the insulation area during processing, the entire cathode must be replaced or recoated, resulting in reduced processing efficiency. Second, integral coating is difficult to form an insulation distribution that meets the differentiated requirements of each cross section on a three-dimensional curved surface, resulting in uneven processing allowance. Third, the boundary accuracy of the coating process is limited, making it difficult to meet the surface accuracy requirements in situations where precise control of the insulation boundary is required.

[0023] According to an embodiment of this invention, a cathode partial insulation device for electrolytic machining is provided, used to provide adjustable partial insulation coverage to the cathode surface during electrolytic machining. The cathode partial insulation device for electrolytic machining includes at least a cathode body 1 and a plurality of insulation modules 2, wherein the insulation modules 2 and the cathode body 1 form a detachable mechanical connection.

[0024] The cathode body 1 is a tool electrode made of conductive metal, and its working surface has a three-dimensional curved shape, which corresponds to the profile of the workpiece to be processed. Multiple mounting slots are formed on the working surface of the cathode body 1, and these slots are distributed in a grid pattern along the curved contour of the working surface. Each mounting slot is a recessed cavity structure formed on the surface of the cathode body 1, with the opening of the cavity facing outwards from the cathode working surface.

[0025] The inner wall of the mounting slot is provided with a snap-fit ​​part, which is an annular flange or groove structure extending circumferentially along the inner wall of the cavity. The cathode body 1 is also provided with positioning pin holes 7 corresponding to each mounting slot. The positioning pin holes 7 are opened at adjacent positions of the mounting slots and penetrate the surface of the cathode body 1.

[0026] The insulation module 2 is an independently detachable insulation unit. Each insulation module 2 includes an insulator and a snap-fit ​​connection part 6. The insulator is made of an insulating material that is resistant to electrolyte corrosion. Its outer surface shape matches the opening shape of the mounting slot. When the insulation module 2 is installed in the mounting slot, the outer surface of the insulator forms a continuous curved surface with the working surface of the cathode body 1.

[0027] The snap-fit ​​connection part 6 is integrally formed with the insulator and is located on the side of the insulator facing away from the working surface. Its structure is adapted to the snap-fit ​​mating part in the mounting slot. When the insulating module 2 is inserted into the mounting slot, the snap-fit ​​connection part 6 and the snap-fit ​​mating part form a snap-fit ​​engagement, fixing the insulating module 2 in the mounting slot. When a disassembly force is applied, the snap-fit ​​connection part 6 can disengage from the snap-fit ​​mating part, allowing the insulating module 2 to be removed from the mounting slot.

[0028] The insulation module 2 is also equipped with a positioning pin, which is integrally formed with the insulator and protrudes outward from the back of the insulator. Its position corresponds to the positioning pin hole 7 on the cathode body 1. During installation, the positioning pin is inserted into the positioning pin hole 7. The gap fit between the positioning pin and the positioning pin hole 7 ensures the positional accuracy and repeatability of the insulation module 2 in the installation slot.

[0029] In some embodiments, the snap-fit ​​part is an annular groove circumferentially arranged along the inner wall of the mounting slot, and the snap-fit ​​connection part 6 is an elastic claw circumferentially arranged along the back side of the insulator. The elastic claw undergoes elastic deformation during insertion, and after passing the edge of the groove, it springs back and snaps into the groove, forming a locking fit.

[0030] In some embodiments, the outer surface of the insulator is provided with a sealing lip that extends circumferentially along the insulator. When the insulating module 2 is installed in place, the sealing lip fits tightly against the opening edge of the mounting slot, preventing electrolyte from seeping into the mating gap between the insulating module 2 and the mounting slot.

[0031] Furthermore, to adapt to the varying insulation coverage requirements at different processing stages, a modular component library is formed by configuring insulation modules 2 of various specifications. The modular component library includes insulation modules 2 with different coverage areas. Insulation modules 2 with larger coverage areas can span multiple adjacent mounting slots and simultaneously engage with multiple mounting slots via multiple snap-fit ​​connections 6; insulation modules 2 with smaller coverage areas occupy only a portion of a single mounting slot. The modular component library also includes insulation modules 2 with different thicknesses. After installation, insulation modules 2 of different thicknesses have different protrusion heights relative to the cathode working surface, which can be used to adjust the processing clearance in localized areas.

[0032] Furthermore, in order to facilitate the identification and management of insulation modules 2 of different specifications, each insulation module 2 has a specification marking area on its outer surface. The specification marking area indicates the coverage area and thickness specifications of the corresponding insulation module 2 through color coding or raised symbols.

[0033] According to this embodiment, the electrolytic processing process includes the following steps: Obtain the surface data of the workpiece to be processed, analyze the electrolytic machining allowance distribution requirements at each cross-section position based on the surface distortion characteristics, and determine the required insulation configuration scheme for each region of the cathode.

[0034] According to the insulation configuration scheme, select the corresponding specification of insulation module 2 from the modular component library, and install the insulation module 2 one by one into the corresponding mounting slot of the cathode body 1. During installation, align the positioning pin of the insulation module 2 with the positioning pin hole 7 of the cathode body 1, press the insulation module 2 towards the mounting slot, and lock it after the snap-fit ​​connection part 6 passes over the snap-fit ​​mating part, thus completing the installation of a single insulation module 2. Repeat the above operation until all insulation modules 2 are installed.

[0035] The installed cathode is then assembled onto an electrolytic machining tool for the first stage of electrolytic machining. During the machining process, the area with the insulating module 2 installed does not undergo an electrolytic reaction, while the area without the insulating module 2 is considered the effective machining area and participates in the electrolytic reaction.

[0036] After the first stage of processing reaches the preset depth, processing is paused and the cathode is removed. Based on the intermediate test results, it is determined whether the insulation configuration needs adjustment. If adjustment is required, some insulation modules 2 are disassembled or replaced with insulation modules 2 of different specifications. During disassembly, a force is applied to the insulation module 2 in the disengagement direction to disengage the snap-fit ​​connection part 6 from the snap-fit ​​mating part, and the insulation module 2 is removed from the mounting slot.

[0037] The adjusted cathode is reassembled onto the machine tool for subsequent electrolytic machining. The process of inspection, adjustment, and machining is repeated until the entire twisted surface is machined.

[0038] In some embodiments, before the first stage of processing, the method further includes filling the mounting slot where the insulating module 2 is not installed with a conductive filler. The conductive filler is a conductive block that matches the shape of the mounting slot. Its structure is the same as that of the insulating module 2, and it also has a snap-fit ​​connection part 6 and a positioning pin, which are fixed in the mounting slot by snap-fit ​​engagement. The outer surface of the conductive filler is flush with the cathode working surface, so that the cathode working surface maintains a continuous curved surface shape. The conductive filler and the cathode body 1 form an electrical connection, so that the area where the conductive filler is located participates in the electrolytic processing.

[0039] Technical effects of this embodiment; The cathode local insulation device for electrolytic machining provided in this embodiment adopts a modular assembly structure to decompose the overall insulation layer into multiple independent insulation units.

[0040] Since the insulating module 2 and the cathode body 1 are connected by a snap-fit ​​connection part 6 and a snap-fit ​​mating part, each insulating module 2 can be independently disassembled and assembled without affecting other modules. This overcomes the limitation that the overall coated insulating layer cannot be locally adjusted, and the distribution of the insulating area can be flexibly configured according to processing requirements.

[0041] Since the installation slots are distributed in a grid pattern along the three-dimensional curved working surface of the cathode body 1, the outer surface of the insulation module 2 after installation forms a continuous curved surface with the working surface. Therefore, the insulation area is configured in three-dimensional space, which meets the needs of differentiated insulation distribution for complex tortuous surfaces.

[0042] Since the insulation module 2 can be disassembled, replaced, or reassembled during processing intervals, it has the ability to dynamically adjust the insulation area in stages, enabling a single cathode to adapt to multi-stage, variable-parameter processing requirements.

[0043] The fit between the locating pin and the locating pin hole 7 ensures the positional accuracy of the insulation module 2 during repeated installation, thus guaranteeing the consistency of the insulation boundary position during the phased processing, which is beneficial to improving the contour accuracy of the surface processing.

[0044] Implementation Method Two: In electrolytic machining, the boundary position of the insulating layer on the cathode surface determines the boundary between the electrolytic reaction area and the non-reaction area, and the insulating boundary directly affects the forming contour accuracy of the workpiece. When machining tortuous surface workpieces such as integral bladed disks of aircraft engines, the insulating boundary needs to be precisely positioned along the three-dimensional curved surface, and deviations in the boundary position will lead to a decrease in the surface contour accuracy.

[0045] In existing technologies, cathode insulating layers are mainly formed using spraying or dip coating processes. Spraying processes have the following drawbacks when forming insulating boundaries: First, the splashing and flowing of paint during spraying creates a gradual transition zone in the boundary area, blurring the boundary position and making it difficult to form a clear dividing line; second, when spraying on complex three-dimensional curved surfaces, the angle and distance at which different parts of the surface receive the paint vary, resulting in uneven coating thickness; third, the insulating layer formed by spraying is fixedly bonded to the cathode substrate, making it impossible to change the distribution of the insulating area during processing.

[0046] For machining twisted surfaces, the ideal machining method is to gradually change the distribution of the insulating region as the machining depth increases to adapt to changes in the twist angle of the surface. The fixed boundaries of existing sprayed insulating layers cannot meet this requirement, limiting the machining accuracy and efficiency of twisted surfaces.

[0047] According to an embodiment of this invention, a cathode partial insulation device for electrolytic machining is provided, used to form a clearly defined and step-adjustable insulating cover on the cathode surface. The cathode partial insulation device for electrolytic machining includes at least a cathode body 1 and a flexible insulating film 5, the flexible insulating film 5 being attached to the working surface of the cathode body 1 by a peelable adhesive method.

[0048] The cathode body 1 is a tool electrode made of conductive metal, and its working surface has a three-dimensional curved shape. The working surface of the cathode body 1 has undergone surface treatment to achieve a surface condition suitable for bonding.

[0049] The flexible insulating film 5 is a prefabricated thin-film insulating cover, including a film substrate, a weakening line 3, a traction label 4, and an adhesive layer.

[0050] The membrane substrate is made of a polymer film resistant to electrolyte corrosion and possesses flexibility that allows for bending and deformation. The planar unfolded shape of the membrane substrate is determined based on the curved unfolded profile of the working surface of the cathode body 1. When the membrane substrate is attached to the working surface, it can conform to the shape of the three-dimensional curved surface through bending deformation. The thickness of the membrane substrate is minimized while ensuring insulation performance to facilitate deformation adaptability when conforming to the curved surface.

[0051] The weakening line 3 is a thinning structure set along a predetermined path on the membrane substrate, dividing the membrane substrate into multiple independent sections. The depth of the weakening line 3 is less than the thickness of the membrane substrate, allowing each section to remain connected at the weakening line 3, but with reduced connection strength. When a tearing force is applied along the weakening line 3, the membrane substrate breaks and separates along the weakening line 3, separating adjacent sections. The path of the weakening line 3 is determined according to the boundaries of the areas to be exposed at each stage of the processing, and the shape and size of each section correspond to the insulation requirements of each processing stage.

[0052] The traction tag 4 is a strip-shaped portion extending outward from the edge of each partition, integrally formed with the membrane substrate of the corresponding partition, and extends to the outside of the cathode working area. The traction tag 4 is used to provide a force point during the tearing operation. The operator applies tearing force to the partition by pulling the traction tag 4, causing the corresponding partition to separate from the adjacent partition along the weakening line 3 and peel off from the cathode surface.

[0053] The adhesive layer is located on the side of the membrane substrate facing away from the working surface, and the adhesive layer is formed using a peelable adhesive. The peelable adhesive forms sufficient adhesive strength with the surface of the cathode body 1, so that the flexible insulating film 5 remains attached and does not fall off during the electrolytic processing; at the same time, the peelable adhesive has the characteristic of being able to be peeled off in one piece, so that when a peeling force is applied by pulling the tag 4, the adhesive layer can be completely peeled off from the cathode surface without leaving any residue.

[0054] In some embodiments, the weakening line 3 is formed by laser etching. The laser scans the surface of the film substrate along a preset path, causing the film substrate to locally vaporize along the laser path to form a groove-like thinning structure. The depth of the groove is controlled by the laser power and scanning speed.

[0055] In some embodiments, the weakening line 3 is formed by mechanical indentation. The molding die applies pressure to the film substrate along a preset path, causing the film substrate to undergo plastic deformation along the indentation path to form a groove-shaped thinning structure.

[0056] In some embodiments, each partition is provided with a region identifier, which is formed on the outer surface of the membrane substrate by printing or embossing, indicating the processing stage number of the corresponding partition. The operator determines which partition should be removed at each stage based on the region identifier.

[0057] Furthermore, to guide the tear along the weakening line 3 without deviation during the tearing process, guide reinforcement strips are provided on both sides of the weakening line 3. These guide reinforcement strips are locally thickened areas extending parallel to both sides of the weakening line 3, formed by coating or hot-pressing an additional layer at the corresponding position on the membrane substrate. The additional layer is bonded to the membrane substrate. The strength of the thickened areas is higher than that at the weakening line 3. When tearing force is applied, the tear preferentially develops along the weakening line 3, where the strength is lowest, and the guide reinforcement strips prevent the tear from deviating to either side.

[0058] Furthermore, to facilitate the bonding and positioning of the flexible insulating film 5 on complex curved surfaces, positioning marks are provided on the film substrate, and positioning references corresponding to the positioning marks are provided on the working surface of the cathode body 1. The positioning marks are crosshairs or circular markings printed or formed on the edge of the film substrate, and the positioning references are corresponding patterns engraved or etched on the edge of the working surface of the cathode body 1. During bonding, the operator aligns the positioning marks with the positioning references to ensure accurate bonding of the flexible insulating film 5 on the cathode surface.

[0059] Furthermore, to improve the durability of the flexible insulating membrane 5 in an electrolyte environment, a corrosion-resistant coating is provided on the outer surface of the membrane substrate. The corrosion-resistant coating covers the side of the membrane substrate facing the electrolyte, preventing the electrolyte from corroding the membrane substrate.

[0060] The steps to be performed; According to this embodiment, the electrolytic processing process includes the following steps: Based on the surface data of the workpiece to be processed and the processing requirements, the distribution of the insulation area required for each processing stage is determined. According to the changes in the insulation boundaries at each stage, the path of the weakening line 3 is planned, and the flexible insulating film 5 is divided into multiple zones corresponding to each stage.

[0061] A flexible insulating film 5 is prepared according to the planned partition pattern, forming a film substrate, a weakening line 3, a traction label 4, and an adhesive layer.

[0062] The flexible insulating film 5 is attached to the working surface of the cathode body 1. During attachment, the positioning marks are aligned with the positioning reference on the cathode body 1, and the flexibility of the film substrate is used to gradually conform it to the three-dimensional curved surface, expelling air bubbles between the film substrate and the working surface, so that the adhesive layer is tightly bonded to the working surface.

[0063] The attached cathode is assembled onto an electrolytic machining tool for the first stage of electrolytic machining. At this time, all sections of the flexible insulating film 5 cover the cathode surface, and only the preset initial exposed area (the area not covered by the flexible insulating film 5) participates in the electrolytic reaction.

[0064] After the first stage of processing is completed, processing is paused. According to the processing requirements, the traction tag 4 of the first partition is pulled, and the first partition is peeled off from the cathode surface along the weakening line 3. After peeling, the area originally covered by the first partition is exposed and becomes a new effective processing area.

[0065] The second stage of electrolytic processing continues, with the newly exposed areas participating in the electrolytic reaction.

[0066] Repeat the process of tearing off the partitions and processing, tearing off each partition in sequence according to the preset stage order, gradually expanding the effective processing area until the processing of the entire twisted surface is completed.

[0067] In some embodiments, before attaching the flexible insulating film 5, the process further includes cleaning and activating the working surface of the cathode body 1 to remove surface oil and oxide layers, thereby improving the bonding reliability between the adhesive layer and the working surface.

[0068] Technical effects of this embodiment; The cathode local insulation device for electrolytic machining provided in this embodiment uses a prefabricated partitioned flexible insulating film 5 instead of the spray-coated insulating layer.

[0069] Since the weakening line 3 is pre-formed on the film substrate by laser marking or mechanical indentation, the path position of the weakening line 3 is precisely determined in the preparation stage. Therefore, the position of the insulation boundary is precisely defined by the weakening line 3, which overcomes the problem of blurred boundaries in the spraying process and forms a clear dividing line between the insulating area and the non-insulating area.

[0070] Since the membrane substrate is made of a flexible polymer film, it can be bent and deformed to fit the three-dimensional curved surface of the cathode body 1, thus achieving insulation coverage on complex twisted surfaces and adapting to the geometry of various parts of the curved surface.

[0071] Because the flexible insulating film 5 is divided into multiple independent sections by the weakening line 3, each section can be peeled off one by one by pulling the tag 4, thus enabling the ability to adjust the insulation area in stages during processing. Each time a section is peeled off, the insulation coverage area shrinks accordingly, and the effective processing area expands accordingly, so that the insulation boundary changes gradually with the processing stage, adapting to the need for gradual adjustment of the insulation area in twisted surface processing.

[0072] Because the adhesive layer is formed using a peelable adhesive, it can be completely peeled off from the cathode surface without leaving any residue when removed. Therefore, the newly exposed cathode surface remains clean and conductive, without affecting the uniformity of the electrolytic reaction in subsequent processing stages.

Claims

1. A cathode local insulation device for electrolytic machining, characterized in that, include: The cathode body is made of conductive material and its working surface is a three-dimensional curved surface. The working surface is provided with multiple mounting slots, which are distributed along the curved contour of the working surface. Multiple detachable insulating units, each of the detachable insulating units including an insulator and a detachable connection structure, the insulator being made of insulating material, and the detachable connection structure being disposed on the side of the insulator facing away from the working surface; The inner wall of the mounting slot is provided with a mating part that cooperates with the detachable connection structure. The detachable connection structure and the mating part form a detachable mechanical connection, so that the detachable insulation unit can be independently installed in the mounting slot or removed from the mounting slot.

2. The cathode local insulation device for electrolytic machining according to claim 1, characterized in that, The detachable connection structure is a snap-fit ​​connection part, and the mating part is a snap-fit ​​mating part; the snap-fit ​​mating part is an annular groove arranged circumferentially along the inner wall of the mounting slot, and the snap-fit ​​connection part is an elastic claw arranged circumferentially along the back side of the insulator. The elastic claw undergoes elastic deformation during insertion and is locked into the annular groove to form a locking fit.

3. The cathode local insulation device for electrolytic machining according to claim 1, characterized in that, The cathode body is provided with a positioning pin hole, and the detachable insulating unit is provided with a positioning pin corresponding to the positioning pin hole. The positioning pin is integrally formed with the insulator and protrudes outward from the back of the insulator. During installation, the positioning pin is inserted into the positioning pin hole to form a positioning fit.

4. The cathode local insulation device for electrolytic machining according to claim 1, characterized in that, The outer surface of the insulator is provided with a sealing lip, which extends circumferentially along the insulator. When the detachable insulating unit is installed in place, the sealing lip fits tightly against the opening edge of the mounting slot.

5. The cathode local insulation device for electrolytic machining according to claim 1, characterized in that, It also includes a conductive filler, which is a conductive block that matches the shape of the mounting slot. Its structure is the same as that of the detachable insulating unit. It is also provided with a detachable connection structure and a positioning pin. It is fixed in the mounting slot through the detachable connection structure. The outer surface of the conductive filler is flush with the working surface of the cathode body. The conductive filler and the cathode body are electrically connected.

6. A cathode local insulation device for electrolytic machining, characterized in that, include: The cathode body is made of conductive material and its working surface has a three-dimensional curved shape. A flexible insulating film includes a film substrate, weakening lines, traction tags, and an adhesive layer. The film substrate is made of a flexible insulating material and can be bent and deformed to conform to the three-dimensional curved working surface of the cathode body. The weakening lines are localized thinning structures set on the film substrate along a preset path, dividing the film substrate into multiple independent sections. The traction tags are strip-shaped portions extending outward from the edges of each section. The adhesive layer is located on the side of the film substrate facing away from the working surface and is formed using a peelable adhesive material. When a tearing force is applied along the weakening line, the film substrate breaks and separates along the weakening line, separating adjacent sections and enabling them to be peeled off from the cathode body surface.

7. The cathode local insulation device for electrolytic machining according to claim 6, characterized in that, The weakening lines are formed by laser scribing. The laser scans the surface of the membrane substrate along a preset path, causing the membrane substrate to be locally vaporized along the laser path to form a groove-shaped thinning structure.

8. The cathode local insulation device for electrolytic machining according to claim 6, characterized in that, The weakening line is provided with guide reinforcement strips on both sides. The guide reinforcement strips are locally thickened areas that extend parallel to both sides of the weakening line. The strength of the guide reinforcement strips is higher than that of the weakening line. When tearing force is applied, the tear develops along the weakening line.

9. The cathode local insulation device for electrolytic machining according to claim 6, characterized in that, The membrane substrate is provided with positioning marks, and the working surface of the cathode body is provided with positioning references corresponding to the positioning marks. When attaching, the positioning marks are aligned with the positioning references to ensure the attachment position of the flexible insulating film on the surface of the cathode body.

10. The cathode local insulation device for electrolytic machining according to claim 6, characterized in that, Each of the partitions is provided with a region identifier, which is formed on the outer surface of the membrane substrate and is used to indicate the processing stage number corresponding to the partition; the outer surface of the membrane substrate is also provided with a corrosion-resistant coating, which covers the side of the membrane substrate facing the electrolyte.

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