Additive manufacturing inner channel redundancy removal molded surface finishing electrochemical machining electrode and method

Abstract

The invention relates to the technical field of electrochemical machining and additive manufacturing post-treatment, and discloses an additive manufacturing inner channel redundancy removal molded surface finishing electrochemical machining electrode and method. The electrode comprises a pull wire, a front-end electrode, a front-end insulation sleeve wrapping the front-end electrode, a rear-end flexible electrode, an insulation isolation layer, electrode insulation bristles, a front-end flexible electrode power line, a rear-end flexible electrode power line and a mooring line, the front-end electrode is used for accurately removing an auxiliary support, and the rear-end flexible electrode is used for surface finishing. The electrode insulation seta provide a self-centering function to ensure that a machining gap is uniform, and the machining method comprises the steps of electrode feeding, electrolytic removal of an auxiliary support, surface finishing and dynamic current regulation and control. The front-end electrode and the rear-end flexible electrode are combined, support is accurately removed, the surface is polished, over-corrosion is avoided, the precision is improved through segmented current control, loss is reduced, electrode insulation seta ensure centering, electrolyte flowing is optimized, deposition is prevented, the flexible woven electrode adapts to channel change, and a blind area is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic machining and additive manufacturing post-processing, and in particular to an electrolytic machining electrode and method for removing excess material from an inner channel of additive manufacturing and trimming the profile. Background Art

[0002] In additively manufactured parts, the internal channel structure is often complex, with centerlines that can be curved or even show significant meandering variations. The channel's cross-sectional dimensions and shape can also be non-uniform. These characteristics complicate subsequent processing, particularly ensuring surface quality and dimensional accuracy while removing residual material and auxiliary supports generated during the printing process. This has been a long-standing technical challenge.

[0003] Currently, the main methods used for surface finishing of channels with larger cross-sections include manual polishing, abrasive flow machining, electrochemical polishing, water jetting, sandblasting, CNC grinding and polishing, and laser polishing. Abrasive flow and electrochemical polishing are considered more suitable for channels with complex surfaces and complex centerline structures due to their greater accessibility.

[0004] Abrasive flow machining relies on flowing abrasive to remove material from the channel surface, but this method still has obvious limitations in its application. Overcutting is prone to occur at the entrance, resulting in local dimensional deviations, while areas with large angle changes inside the channel are often difficult to evenly finish. In addition, the cleaning of abrasive residues is also an important issue. If not handled properly, it may affect the final performance of the part. At the same time, the efficiency of abrasive flow machining is low, and the processing area cannot be precisely controlled. Especially when processing internal channels with auxiliary supports, it is difficult to effectively remove the support structure while ensuring dimensional accuracy. When trying to completely remove the support, other areas are often over-etched, affecting the final part accuracy.

[0005] Unlike abrasive flow machining, electrochemical machining utilizes an electrolyte as the machining medium, rather than relying on solid abrasives. This makes it suitable for finishing curved or narrow channels. However, this method requires that the electrode and channel structure match, otherwise machining quality may be compromised. Maintaining good electrode clearance within complex channels while ensuring machining uniformity is a key challenge.

[0006] Some existing patents attempt to address the adaptability issues of electrochemical machining. For example, JP1987224522A proposes a flexible metal electrode wrapped with a spiral of insulating material. The electrode reciprocates within a curved tube filled with electrolyte to smooth the channel surface. However, this solution primarily focuses on reducing surface roughness and does not provide specific solutions for removing residue or support structures within the channel.

[0007] The comparative document with announcement number CN112077402A proposes an electrolytic machining tool electrode that combines a flexible metal electrode with an elastic insulating column. This solution supports the flexible metal electrode through multiple elastic insulating columns, allowing it to float inside the channel and avoid direct contact with the channel wall to prevent short circuits. When in use, the tool electrode and the workpiece are immersed in the electrolyte together, and connected to the positive and negative poles of the power supply respectively. By moving the electrode, the entire channel surface is uniformly electrolytically smoothed. This method enhances the flexibility of electrolytic machining, can be applied to internal channels with different degrees of curvature to a certain extent, and improves the finishing quality.

[0008] Overall, although the existing electrolytic machining scheme can improve the roughness of the internal channel surface to a certain extent, there is still much room for improvement in terms of residue cleaning in the channel after additive manufacturing, auxiliary support removal, and processing consistency. Summary of the Invention

[0009] In response to the shortcomings of the existing technology, the present invention provides an electrolytic machining electrode and method for removing excess material from the internal channel of additive manufacturing and trimming the surface, which solves the problem of removing residues and auxiliary supports in the internal channel of additive manufacturing.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: an electrolytic machining electrode for removing excess material from an inner channel of an additive manufacturing process and finishing the surface, comprising:

[0011] Traction line, front-end electrode, front-end insulating sleeve, rear-end flexible electrode, insulating isolation layer, electrode insulating bristles, front-end flexible electrode power line, rear-end flexible electrode power line, mooring line;

[0012] The side and rear end of the front end electrode are wrapped by the front end insulating sleeve, and the edge of the front end insulating sleeve extends forward beyond the exposed part of the front end electrode to form an electrochemical machining gap. The rear end flexible electrode is formed by weaving or winding a plurality of metal wires around the outer insulating layer of the rear end flexible electrode power cord, and its cross-sectional size is smaller than the channel cross-sectional size minus the value of the electrochemical machining gap. The insulating isolation layer separates the front end electrode and the rear end flexible electrode. The electrode insulating bristles pass through the metal wire structure of the rear end flexible electrode, and the exposed length at both ends is greater than the machining gap and extends outward in a natural state. The traction line enters the channel entrance and is led out from the outlet under the action of the electrolyte flow field, and is connected to the front end insulating sleeve or the front end electrode. The mooring line is fixedly connected to the rear end flexible electrode, the front end flexible electrode power cord or the rear end flexible electrode power cord, and is used to pull the electrode out of the entrance again.

[0013] Preferably, the electrode insulating bristles are evenly distributed axially along the rear end flexible electrode and arranged radially at intervals. Under the action of traction force, they elastically deform to maintain a symmetrical gap between the rear end flexible electrode and the inner wall of the channel. In the natural state, the sum of the cross-sectional dimensions of the electrode insulating bristles and the rear end flexible electrode is greater than the cross-sectional dimension of the channel. The electrode insulating bristles are multiple highly elastic insulating materials.

[0014] Preferably, the forward extension length of the edge of the front end insulating sleeve is greater than the width of the electrochemical machining gap, so as to prevent the front end electrode from contacting the auxiliary support in the channel.

[0015] Preferably, the rear flexible electrode power line passes through the insulating isolation layer to be insulated and isolated from the front electrode, and the front flexible electrode power line and the rear flexible electrode power line are independently connected to power source one and power source two, respectively.

[0016] Preferably, the cross-sectional dimensions of the metal wire braided structure of the rear flexible electrode are larger than the cross-sectional dimensions of the channel in a natural state, and the channel cross-sectional dimensions are adapted to changes through elastic compression and deformation of the electrode insulating bristles.

[0017] Preferably, the front end electrode is made of metal material, and its front end is conical or circular.

[0018] The present invention also provides a method for removing excess material from an inner channel of an electrolytic machining electrode by surface finishing based on the additive manufacturing method, which is characterized by comprising the following steps:

[0019] S1, the electrode is introduced into the channel through the pulling wire, and the electrolyte is continuously flushed into the inlet and flows out from the outlet;

[0020] S2. When the traction wire stops feeding because the front end insulation sleeve contacts the auxiliary support, the power supply of the front end electrode is started to directionally erode the auxiliary support;

[0021] S3. After the auxiliary support is removed, the traction line feed is restarted and the power supply of the rear flexible electrode is started. The machining gap is maintained by the electrode insulating bristles, and the inner surface of the channel is electrolytically smoothed.

[0022] S4, dynamically adjusting the power current density of the rear flexible electrode according to the change of the channel cross-sectional size;

[0023] S5. After processing, the electrode is recovered through the mooring line

[0024] Preferably, in step S2, the power supply current density of the front-end electrode is greater than the power supply current density of the rear-end flexible electrode, and the power supply of the rear-end flexible electrode is turned off during the auxiliary support removal stage.

[0025] Preferably, in step S3, the electrode insulating bristles are elastically bent to reduce the processing gap when the channel cross-sectional size is reduced, and are elastically restored to expand the gap when the cross-sectional size is increased.

[0026] The present invention provides an electrolytic machining electrode and method for removing excess material from an inner channel in additive manufacturing and trimming the profile.

[0027] It has the following beneficial effects:

[0028] 1. The present invention achieves the dual goals of auxiliary support removal and channel surface smoothing by adopting a processing method that combines a front-end electrode with a rear-end flexible electrode. The front-end electrode controls the electric field action area through an insulating cover to ensure that only the support structure is electrolytically processed without affecting the channel sidewall. Compared with the traditional single-electrode processing method, the present invention avoids the problems of incomplete support removal or over-etching of the channel surface.

[0029] 2. The present invention optimizes the energy distribution in different processing stages by separately controlling the current waveforms of the front-end electrode and the rear-end flexible electrode. The front-end electrode accurately removes the support at high current density, while the rear-end flexible electrode evenly smoothes the surface at low current density. Compared with the traditional fixed current processing method, this solution effectively improves the processing accuracy and reduces unnecessary material loss.

[0030] 3. The present invention arranges electrode insulating bristles on the periphery of the electrode, and utilizes its elastic deformation characteristics to realize the self-centering function in the channel. The bristles can automatically adjust the supporting force according to the change of the channel cross-section to ensure that the electrode is always in the center position, so that the processing gap is uniform and stable. Compared with the traditional rigid support structure, the bristle structure is more adaptable to the variable cross-section channel, and the processing uniformity is greatly improved.

[0031] 4. The bristle support structure of the present invention has an extremely small diameter and takes up almost no additional space. It can provide stable support and allow the electrolyte to flow smoothly. It can effectively discharge the erosion products and prevent deposition and blockage, thereby making the processing process more stable. Compared with the traditional rigid electrode support method, the bristle structure improves the removal efficiency of the electrolysis products and reduces the local over-etching phenomenon.

[0032] 5. The present invention adopts a flexible braided electrode, which can adapt to the shape changes of the channel, ensure that the processing gap in all directions remains consistent, and make the surface finishing effect more uniform. Compared with the processing blind area problem caused by the fixed shape of traditional rigid electrodes, the present invention significantly improves the surface quality through the flexible structure and eliminates local rough spots.

[0033] 6. The rear-end flexible electrode of the present invention is in full contact with the electrolyte, and the entire electrode can effectively participate in the processing, avoiding the processing blind area caused by the insulation layer covering the traditional segmented electrode. This solution improves the electrode utilization rate and enhances the processing uniformity. Compared with the partially exposed electrode method, the processing time is shorter, the efficiency is higher, and the surface quality is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1Schematic diagram of the front and rear electrode insulation isolation layer of the present invention;

[0035] Figure 2 Schematic diagram of the connection relationship of the mooring line of the present invention;

[0036] Figure 3 Flowchart of the method of the present invention.

[0037] Among them, 1. traction line; 2. front end electrode; 3. front end insulating sleeve; 4. rear end flexible electrode; 5. insulating isolation layer; 6. electrode insulating bristles; 7. front end flexible electrode power cord; 8. rear end flexible electrode power cord; 9. mooring line; 10. auxiliary support; 11. power supply 1; 12. power supply 2. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] Please see the attached Figure 1 and attached Figure 2 The embodiment of the present invention provides an electrolytic machining electrode for removing excess material from an inner channel of additive manufacturing and finishing the surface, comprising:

[0040] Pull line 1, front electrode 2, front insulating sleeve 3, rear flexible electrode 4, insulating isolation layer 5, electrode insulating bristles 6, front flexible electrode power line 7, rear flexible electrode power line 8, mooring line 9;

[0041] The side and rear end of the front end electrode 2 are wrapped by the front end insulating sleeve 3, and the edge of the front end insulating sleeve 3 extends forward beyond the exposed part of the front end electrode 2 to form an electrochemical machining gap. The rear end flexible electrode 4 is made of multiple metal wires woven or wound around the outer insulation layer of the rear end flexible electrode power cord 8. Its cross-sectional size is smaller than the channel cross-sectional size minus the value of the electrochemical machining gap. The insulating isolation layer 5 separates the front end electrode 2 and the rear end flexible electrode 4. The electrode insulating bristles 6 pass through the metal wire structure of the rear end flexible electrode 4. The exposed length at both ends is greater than the machining gap and extends outward in a natural state. The traction line 1 enters the channel entrance and exits the outlet under the action of the electrolyte flow field, and is connected to the front end insulating sleeve 3 or the front end electrode 2. The mooring line 9 is fixedly connected to the rear end flexible electrode 4, the front end flexible electrode power cord 7 or the rear end flexible electrode power cord 8, and is used to pull the electrode out from the entrance again.

[0042] Specifically, the pull wire 1 enters the channel driven by the flow of electrolyte. Feeding is stopped when the edge of the front insulating sleeve 3 contacts the auxiliary support 10. When the front electrode 2 is energized, the electrolyte creates a high electric field density in the exposed area, directionally etching away the support structure. The rear electrode remains de-energized to prevent overcutting of the channel surface.

[0043] The rear flexible electrode 4 is constructed of braided metal wire. When naturally extended, the outer insulating bristles extend beyond the channel's cross-section. Traction forces the bristles to elastically compress, forming symmetrical support points that automatically align the electrode's center with the channel's axis. Electrolyte flows at high speed through the gaps between the bristles, flushing away reaction products.

[0044] As the cross-section changes, the bristles bend adaptively: in narrow areas, the bristles tilt more, reducing the machining gap; in expanding areas, the bristles stretch back, expanding the erosion range. The elastic support range covers the extreme tolerances of the channel dimensions, maintaining a stable gap.

[0045] After the auxiliary support 10 is removed, the traction wire 1 resumes feeding, and the rear electrode is energized and activated. Under low current density, the braided wire electrode forms a uniform electric field with the channel surface, gradually stripping away adhered powder. Processing parameters are dynamically adjusted with the traction speed to match the material removal requirements of different curvature sections.

[0046] After the operation is completed, the mooring line 9 pulls the electrode in reverse and exits. If the channel size suddenly exceeds the limit, a new electrode module with appropriate bristle length and braid density is replaced. The split electrode structure allows for independent replacement of the front or back components, reducing maintenance costs.

[0047] The electrode insulating bristles 6 are evenly distributed axially along the rear end flexible electrode 4 and arranged radially at intervals. Under the action of traction force, they elastically deform to maintain a symmetrical gap between the rear end flexible electrode 4 and the inner wall of the channel. In the natural state, the sum of the cross-sectional dimensions of the electrode insulating bristles 6 and the rear end flexible electrode 4 is greater than the cross-sectional dimensions of the channel. The electrode insulating bristles 6 are multiple highly elastic insulating materials.

[0048] Specifically, under traction, the highly elastic insulating bristles are squeezed along the surface of the braided electrode. When stretched naturally, the combined cross-section of the bristles and electrode exceeds the channel dimensions. The deformed bristles form multi-point symmetrical supports, forcing the electrode centerline to align with the channel axis.

[0049] When the electrolyte flows through the gaps between the bristles, it flushes the erosion products between the electrode and the channel wall. In areas with varying cross-sections, the bristle bending angles are adaptively adjusted: in narrow areas, the bristles fall more sharply to maintain the minimum machining gap; in expanded areas, the bristles partially rebound to expand the erosion coverage.

[0050] The radially spaced bristles create discrete contact points, reducing resistance to electrolyte flow. Their uniform axial arrangement ensures stable support during electrode movement and prevents radial deviation. The elastic nature of the material allows the bristles to quickly return to their original shape after repeated deformation, extending their service life.

[0051] In general, the electrode insulating bristles 6 are multiple strands of highly elastic insulating material, such as synthetic fiber brush filaments. When the rear flexible electrode 4 is made by braiding or winding multiple bundles of metal wire, each bristle passes through the rear flexible electrode 4, with both ends exposed by a length greater than the machining gap. The bristles are fastened to the rear flexible electrode 4 by the braiding or winding force. The bristles are evenly distributed axially on the rear flexible electrode 4 and preferably spaced radially (forming a shape similar to the middle of a test tube brush). After the flexible electrode enters the channel, because the cross-sectional dimensions of the rear flexible electrode 4 and the additional bristles are larger than the channel cross-sectional dimensions, the bristles deform backward under the action of traction while still maintaining a certain degree of elasticity. The evenly distributed bristles around the rear flexible electrode 4 form an effective, self-centering support, keeping the center of the rear flexible electrode 4 approximately on the channel centerline, and the elastic bristles provide insulation between the outer side of the flexible electrode and the inner wall of the channel. The advantages of this design are: in addition to the elastic support provided by the bristles for the rear flexible electrode 4 to self-align, the gap between the rear flexible electrode 4 and the inner wall 13 of the workpiece channel can still be used to circulate the electrolyte 14, thereby discharging the heat and erosion products generated by the processing out of the processing area. Furthermore, the elasticity of the bristles allows them to deform over a wide range without blocking the machining channel. When the cross-sectional dimensions decrease, the distance between the rear flexible electrode 4 and the inner surface of the channel decreases, causing the bristles to bend or tilt more. When the cross-sectional dimensions increase, the degree of bending or tilting decreases, but the bristles still provide self-centering support during machining. Therefore, the entire flexible electrode system can perform stable machining with radially symmetrical clearances in channels with variable cross-sectional dimensions. Significant changes in the cross-sectional dimensions or channel length require replacement with new electrodes of the corresponding dimensions.

[0052] The edge of the front end insulating sleeve 3 extends forward by a length greater than the width of the electrochemical machining gap, and is used to prevent the front end electrode 2 from contacting the auxiliary support 10 in the channel.

[0053] Specifically, the edge of the front insulating sleeve 3 extends forward to cover the exposed electrode area. As the traction wire 1 advances, the edge of the insulating sleeve first contacts the auxiliary support 10, triggering a stop signal. At that moment of contact, the insulating sleeve forms a mechanical barrier with the support surface, isolating the electrode from direct contact with the support.

[0054] The electrolyte flows in through the gap, creating a concentrated electric field between the exposed electrode surface and the support. High current density results in a directionally etched support structure. The edge of the insulating sleeve is longer than the gap width to prevent lateral electrode deviation and short circuits. During machining, power supply parameters are dynamically adjusted based on support hardness, balancing erosion efficiency and surface quality.

[0055] The gap width is determined by the extension length of the insulating sleeve and the support surface topography. Etched products are discharged from the outlet along with the electrolyte flow, preventing stagnation and interference with the electric field distribution. After the support is cleared, traction wire 1 resumes feeding, and the edge of the insulating sleeve leaves the contact area.

[0056] The rear flexible electrode power line 8 passes through the insulating isolation layer 5 to be insulated and isolated from the front electrode 2, and the front flexible electrode power line 7 and the rear flexible electrode power line 8 are independently connected to power supply 1 11 and power supply 2 12 respectively.

[0057] Specifically, an insulating isolation layer 5 physically separates the front and rear electrode power lines. The front flexible electrode power line 7 is independently connected to Power Supply 1 11, while the rear electrode power line is connected to Power Supply 2 12. During machining, these two power sources are independently controlled: during the auxiliary support 10 removal phase, Power Supply 1 11 delivers a high current density to the front electrode 2; during the surface finishing phase, Power Supply 2 12 activates a low-current mode to drive the rear electrode.

[0058] When the front electrode 2 is energized, the electrolyte creates a strong electric field in the exposed area, rapidly eroding the auxiliary support 10. The rear electrode remains powered off or at a low current level to prevent overcutting of the channel surface. After the support is removed, power supply 11 is disconnected, and power supply 2 12 is increased to the finishing threshold. The two power supplies are interlocked to prevent current crosstalk that could cause uncontrolled machining.

[0059] The insulation layer is resistant to electrolyte corrosion and blocks leakage current between the front and rear electrodes. Power supply parameters are dynamically adjusted by an external controller to match the feed speed of the traction line 1 and the curvature of the channel. The modular design of the electrodes allows individual power cables to be replaced, reducing maintenance complexity.

[0060] The cross-sectional dimensions of the metal wire braided structure of the rear flexible electrode 4 are larger than the channel cross-sectional dimensions in the natural state, and the changes in the channel cross-sectional dimensions are adapted through the elastic compression deformation of the electrode insulating bristles 6 .

[0061] Specifically, the cross-section of the braided wire electrode in its naturally relaxed state is slightly larger than the channel. When traction forces the electrode into the channel, the insulating bristles are squeezed and elastically contracted by the channel walls. This compression and deformation of the bristles releases radial pressure, forcing the braided wire structure to radially contract and conform to the channel's cross-section.

[0062] In narrow areas, the bristles bend more, passively increasing the wire braid density to maintain the minimum machining gap between the electrode and the channel wall. In expanded areas, the bristles rebound and stretch, loosening the wire braid structure and expanding the electrode coverage.

[0063] During elastic compression, the wires slide relative to each other, preventing the structure from becoming stuck. The bristle deformation adapts to the channel's extreme size, ensuring uniform electrolyte flow across different cross-sectional areas. After processing is complete, the traction is removed, and the electrode returns to its original dimensions, facilitating the retrieval of the mooring line 9.

[0064] The front end electrode 2 is made of metal, and its front end is conical or circular.

[0065] Specifically, when the conical or circular electrode tip cuts into the channel opening, the geometry reduces contact resistance. The conductive area of the metal material is exposed, and the electrolyte forms an electric field concentration zone at the electrode tip. Under high current density, the surface of the auxiliary support 10 rapidly ionizes and dissolves.

[0066] An insulating sleeve encases the sides and rear end of the electrode, leaving only the front end exposed. The edge extension mechanically blocks contact between the electrode and the channel wall, forcing a stable erosion gap. As the traction wire 1 advances, the electrode's conical surface guides the direction, preventing stagnation.

[0067] The round tip adapts to the curved channel entrance, evenly distributing the electrolyte flow field. The conical tip penetrates the powder accumulation area and directionally removes the support structure. Processing parameters are dynamically adjusted according to the tip shape: the conical electrode uses pulsed current to improve etching efficiency; the circular electrode uses a constant current mode to ensure surface uniformity.

[0068] When the electrode is retracted, the front geometry reduces friction with the channel wall, preventing secondary scratching of the machined surface.

[0069] Please see the attached Figure 3 A method for removing excess material from an inner channel of an electrochemical machining electrode based on additive manufacturing and surface finishing comprises the following steps:

[0070] S1, the electrode is introduced into the channel through the pulling line 1, and the electrolyte is continuously flushed into the channel from the inlet and flows out from the outlet;

[0071] S2. When the traction wire 1 stops feeding because the front end insulating sleeve 3 contacts the auxiliary support, the power supply of the front end electrode 2 is started to directionally etch away the auxiliary support;

[0072] S3. After the auxiliary support is removed, the traction line 1 is restarted to feed and the power supply of the rear flexible electrode 4 is started. The processing gap is maintained by the electrode insulating bristles 6, and the inner surface of the channel is electrolytically smoothed.

[0073] S4, dynamically adjusting the power current density of the rear flexible electrode 4 according to the change in the channel cross-sectional size;

[0074] S5. After the processing is completed, the electrode is recovered through the mooring line 9.

[0075] In step S2, the power supply current density of the front electrode 2 is greater than the power supply current density of the rear flexible electrode 4, and the power supply of the rear flexible electrode 4 is turned off during the auxiliary support removal stage.

[0076] In step S3 , the electrode insulating bristles 6 elastically bend to reduce the machining gap when the channel cross-sectional size decreases, and elastically recover to expand the gap when the cross-sectional size increases.

[0077] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Additive manufacturing inner channel excess removal and surface finishing electrolytic machining electrode, characterized in that: include: A traction line (1), a front-end electrode (2), a front-end insulating sleeve (3), a rear-end flexible electrode (4), an insulating isolation layer (5), electrode insulating bristles (6), a front-end flexible electrode power line (7), a rear-end flexible electrode power line (8), and a mooring line (9); The side and rear end of the front electrode (2) are wrapped by the front insulating sleeve (3), and the edge of the front insulating sleeve (3) extends forward beyond the exposed part of the front electrode (2) to form an electrochemical machining gap. The rear flexible electrode (4) is formed by weaving or winding a plurality of metal wires around the outer insulating layer of the rear flexible electrode power cord (8), and its cross-sectional size is smaller than the channel cross-sectional size minus the value of the electrochemical machining gap. The insulating isolation layer (5) separates the front electrode (2) and the rear flexible electrode (4). The electrode insulating bristles (6) pass through the metal wire structure of the rear flexible electrode (4), and the exposed length at both ends is greater than the machining gap and extends outward in a natural state. The traction line (1) enters the channel entrance and is led out from the exit under the action of the electrolyte flow field, and is connected to the front insulating sleeve (3) or the front electrode (2). The mooring line (9) is fixedly connected to the rear flexible electrode (4), the front flexible electrode power cord (7) or the rear flexible electrode power cord (8), and is used to re-extract the electrode from the entrance.

2. The electrolytic machining electrode for removing excess material from inner channels of additive manufacturing according to claim 1, characterized in that: The electrode insulating bristles (6) are evenly distributed along the axial direction of the rear flexible electrode (4) and arranged at intervals in the radial direction. Under the action of traction, they elastically deform to maintain a symmetrical gap between the rear flexible electrode (4) and the inner wall of the channel. In a natural state, the sum of the cross-sectional dimensions of the electrode insulating bristles and the rear flexible electrode (4) is greater than the cross-sectional dimension of the channel. The electrode insulating bristles (6) are multiple pieces of highly elastic insulating material.

3. The electrochemical machining electrode for removing excess material from inner channels in additive manufacturing according to claim 1, characterized in that: The edge of the front end insulating sleeve (3) extends forward by a length greater than the width of the electrochemical machining gap, and is used to prevent the front end electrode (2) from contacting the auxiliary support (10) in the channel.

4. The electrochemical machining electrode for removing excess material from inner channels in additive manufacturing according to claim 1, characterized in that: The rear flexible electrode power line (8) passes through the insulating isolation layer (5) and is insulated from the front electrode (2), and the front flexible electrode power line (7) and the rear flexible electrode power line (8) are independently connected to power source 1 (11) and power source 2 (12), respectively.

5. The electrochemical machining electrode for removing excess material from inner channels in additive manufacturing according to claim 1, characterized in that: The metal wire braided structure of the rear flexible electrode (4) has a cross-sectional dimension larger than the channel cross-sectional dimension in a natural state, and adapts to channel cross-sectional changes through elastic compression deformation of the electrode insulating bristles (6).

6. The electrochemical machining electrode for removing excess material from inner channels in additive manufacturing according to claim 1, characterized in that: The front end electrode (2) is made of metal material, and its front end is conical or circular.

7. A method for removing excess material from an inner channel of an additively manufactured electrolytic machining electrode according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, the electrode is introduced into the channel through the pulling line (1), and the electrolyte is continuously flushed into the channel from the inlet and discharged from the outlet; S2, when the traction wire (1) stops feeding because the front end insulating sleeve (3) contacts the auxiliary support, starting the power supply of the front end electrode (2) to directionally etch away the auxiliary support; S3, after the auxiliary support is removed, the traction line (1) is restarted to feed and the power supply of the rear flexible electrode (4) is started, and the processing gap is maintained by the electrode insulating bristles (6), and the inner surface of the channel is electrolytically smoothed; S4, dynamically adjusting the power current density of the rear flexible electrode (4) according to the change in the channel cross-sectional size; S5. After the processing is completed, the electrode is recovered through the mooring line (9).

8. The method for removing excess material from an inner channel of an additive manufacturing electrochemical machining electrode and trimming the surface according to claim 7, characterized in that: In step S2, the power supply current density of the front-end electrode (2) is greater than the power supply current density of the rear-end flexible electrode (4), and the power supply of the rear-end flexible electrode (4) is turned off during the auxiliary support removal stage.

9. The method for removing excess material from an inner channel of an additive manufacturing electrochemical machining electrode and trimming the surface according to claim 7, characterized in that: In the step S3, the electrode insulating bristles (6) are elastically bent to reduce the processing gap when the channel cross-sectional size is reduced, and are elastically restored to expand the gap when the cross-sectional size is increased.

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