Electrochemical machining electrode structure based on octopus antenna imitating structure

Abstract

The invention discloses an electrochemical machining electrode based on an octopus antenna imitating structure, and belongs to the technical field of electrochemical machining. The electrode is characterized in that a metal hollow tubular structure is used as a base body, and a non-metal disc of an octopus-antenna-imitating suction cup structure is embedded into the surface of the base body. The center of the non-metal disc is of a hollow structure, and a gradient transition bionic protrusion shape is formed on the combination portion of the non-metal disc and the base body, so that contact between a cathode and an anode in the machining process can be effectively avoided, and short-circuit arc burn is prevented. And through the hollow base body and the hollow structure of the disc, internal flushing liquid can be rapidly discharged, the self-adaptive adsorption function is achieved, the discharging characteristic can be stabilized, and therefore the polishing efficiency is improved. The electrode has the characteristics of high machining efficiency and low element damage rate, and is particularly suitable for electrochemical machining of inner holes with complex shapes.

Description

Technical Field

[0001] The present invention relates to the field of special processing, and particularly to an electrochemical machining electrode structure based on the structure of an octopus tentacle. Background Art

[0002] Additive manufacturing technology is an advanced manufacturing method based on a computer-aided design model. By using high-energy beams such as lasers to melt and stack materials layer by layer, a complete part or component is finally formed. With its high flexibility, short manufacturing process cycle, and significant material saving advantages, this technology has been widely applied in many fields such as aerospace, customized medical implants, and chemical catalysts. Especially in manufacturing workpieces with complex internal channel structures, additive manufacturing technology has shown unique advantages.

[0003] However, additive manufacturing technology still faces some challenges in practical applications. Problems such as balling effect, powder adhesion, and staircase effect result in a rough surface of the machined part with a large number of protrusions, making it difficult to meet the high-precision requirements of workpieces in fields such as aerospace. Therefore, post-processing such as finishing is usually required for such parts. Especially for workpieces with complex internal structures, the poor visibility of their internal channels and limited tool operation space make finishing machining particularly difficult. How to effectively process workpieces with complex curved internal channels has become an urgent problem to be solved in the current manufacturing industry.

[0004] Currently, the commonly used polishing processes for additive manufacturing parts at home and abroad mainly include mechanical polishing, laser polishing, abrasive flow polishing, and chemical polishing. Among them, mechanical polishing is widely used due to its high material removal ability and good surface treatment effect, but its processing procedures are complex and it is difficult to deal with complex internal channels. Although laser polishing is efficient, local high temperature may cause deformation or cracks in the workpiece, and it is difficult for the laser beam to precisely process complex internal channel structures. Abrasive flow polishing has the problem of abrasive residue. Especially in internal channels, it is difficult to completely remove abrasive particles, affecting the control of surface roughness.

[0005] In contrast, electrochemical polishing, as a non-contact processing method, is not restricted by the mechanical properties of materials and mainly achieves material removal through anodic dissolution in an electrochemical reaction. This method has high flexibility and excellent processing effects, and is particularly suitable for the finishing machining of complex internal channels, providing a new way to solve the surface treatment problems in additive manufacturing.

[0006] Although traditional electrochemical polishing techniques can, to a certain extent, solve the processing problems of complex internal channels, the design of their electrode structures still has limitations. Conventional rigid electrodes are difficult to adapt to the geometric changes of complex curved internal channels, resulting in poor processing uniformity, low efficiency, and even possible short circuits or processing failures due to the contact between the electrode and the inner wall of the workpiece. Conventional electrodes produce waste liquid during the processing. If the waste liquid cannot be discharged in time, it will lead to low processing quality and efficiency. Therefore, developing a new electrode structure that can flexibly adapt to complex internal channel structures and ensure efficient and stable processing has become an important research direction in current electrochemical polishing technology. Summary of the Invention

[0007] Object of the Invention:

[0008] In nature, the octopus tentacles, with their unique flexibility and adaptability, can flexibly grasp and manipulate objects in complex environments. This biological characteristic provides new inspiration for the design of electrochemical machining electrodes. Bionics research shows that by imitating the structural characteristics of octopus tentacles, an electrode structure with flexibility and adaptability can be designed, enabling it to freely deform in complex internal channels and closely fit the inner wall of the channel, thereby achieving uniform and efficient electrochemical polishing. In addition, the sucker structure on the surface of the octopus tentacles can also enhance the contact stability between the electrode and the workpiece surface, further improving the processing accuracy and consistency. Its hollow sucker structure and hollow metal conduit can achieve internal and external compound flushing, quickly discharging the waste liquid and electrolytic impurities generated during the processing, and improving the processing efficiency.

[0009] Technical Solution:

[0010] An electrode imitating the octopus tentacle structure, characterized in that: the electrode imitating the octopus tentacle structure is an overall hollow metal conduit, and its pipe wall is provided with radial through grooves distributed at equal angles and uniformly arranged in the axial direction, making it have better flexibility; the bionic sucker unit is made of rubber material and is installed in the radial through grooves through a detachable structure;

[0011] Among them, the bionic sucker unit includes:

[0012] A stepped boss, the inner diameter d of the boss satisfies the relationship: d = 0.8D (D is the outer diameter of the boss). The boss has a certain height, which can effectively prevent direct contact between the metal conduit and the inner surface of the internal channel of the workpiece to be processed and cause short-circuit burns. A central through hole with a diameter of 0.2 - 0.3d is communicated with the inner cavity of the hollow metal conduit for positioning, and at the same time, the electrode imitating the octopus tentacle structure can discharge the internal electrolyte more evenly during the processing. An annular insulating inner buckle skirt is buckled on the inner surface of the electrode to play a fixing role.

[0013] The octopus tentacle structure - inspired electrode according to claim 1 is characterized in that: the distribution density of the bionic sucker units is adjustable, and the height of the stepped bosses can be adaptively adjusted according to the inner hole diameter and curvature of the workpiece to be machined; the hollow metal conduit can be made circular or elliptical according to the shape of the inner channel.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The electrochemical machining electrode structure inspired by the octopus tentacle structure proposed by the present invention is composed of bionic sucker units embedded on a hollow metal conduit, having good flexibility and capable of performing reciprocating and highly curved motions in complex curved inner channels.

[0016] 2. During the polishing process, for complex curved inner channels with poor surface quality, the bionic sucker units can deform and adsorb by virtue of the electrolyte pressure and material flexibility, adsorbing on the relatively convex parts of the surface to achieve uniform and efficient electrolytic polishing. Moreover, the bionic sucker units adsorb on the surface of the complex curved inner channels, improving the contact stability with the surface and enhancing the machining accuracy and consistency.

[0017] 3. The boss - shaped suckers formed by the bionic sucker units can change their boss height and distribution density according to the inner hole diameter and curvature of the part to be machined, avoiding direct contact between the hollow metal conduit and the part to be machined and preventing short - circuit arc burns.

[0018] 4. The hollow - structured bionic sucker units and the hollow metal conduit can achieve internal liquid injection and external discharge, enabling rapid exchange of the electrolyte, timely discharging of waste liquid and replenishing of new electrolyte, thereby improving the machining efficiency.

[0019] 5. The hollow metal conduit can be made elliptical according to the shape of the inner channel, and the bionic sucker units are embedded at both ends of the major axis of the ellipse, enabling machining of nearly right - angled structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an overall schematic diagram of the octopus tentacle structure - inspired electrode;

[0021] Figure 2 is a schematic diagram of the structure of the bionic sucker unit;

[0022] Figure 3 is a schematic diagram of the electrochemical polishing of complex inner channels using the octopus tentacle structure - inspired electrode;

[0023] Figure 4 is a sectional view of the octopus tentacle structure - inspired electrode;

[0024] Figure 5 is a comparison diagram of the morphologies of the circular and elliptical hollow metal conduits of the octopus tentacle structure - inspired electrode.

[0025] The reference numerals in the figure are named as follows: 1. Octopus-antenna-structure electrode; 2. Bionic sucker unit; 3. Hollow metal conduit; 4. Inner-channel surface of the workpiece to be machined; 5. Workpiece to be machined; 6. Liquid collection cavity; 7. Fixture of the first main spindle of the machine tool; 8. Fixture of the second main spindle of the machine tool; 9. Power supply; 10. Circulation system. Detailed implementation manners

[0026] The following provides the detailed implementation manners of the present invention in conjunction with the accompanying drawings.

[0027] According to Figure 1 As shown, the octopus-antenna-structure electrode 1 is composed of a hollow metal conduit 3 made of 304 stainless steel and a rubber bionic sucker unit 2. Four axial through grooves are equally spaced at 90° on the surface of the hollow metal conduit 3, and the bionic sucker unit 2 is assembled on the surface of the hollow metal conduit 3.

[0028] According to Figure 2 As shown, the bionic sucker unit 2 is injection-molded from a corrosion-resistant rubber material. Its base is a stepped cylindrical structure, including: a stepped boss 2-1; a central through hole 2-2 is provided in the center; an annular insulating skirt 2-3 is provided at the bottom. The hollow metal conduit 3 is heated to 120 ± 5 °C, and at the same time, the bionic sucker unit 2 is cooled to -20 ± 5 °C. The interference fit is realized by using the thermal expansion and contraction effect, and the assembly accuracy is controlled within ±0.02 mm and fixed by an internal snap skirt. The spacing of the bionic sucker units 2 can be adjusted according to the curvature of the workpiece, and the standard spacing is 3 - 8 mm. For the setting of the spacing of the bionic sucker units at both ends of the long axis of the elliptical hollow metal conduit, it is necessary to adjust according to the curvature and the spacing on the standard plane to ensure that the surface areas at both ends of the long axis are equal to the standard plane, so as to ensure the uniformity of the electrolyte distribution and the consistency of the machining efficiency.

[0029] According to Figure 3 As shown, the bionic sucker unit 2 is assembled on the surface of the hollow metal conduit 3 by interference fit and internal snap skirt. The internal snap skirt can prevent the bionic sucker unit 2 from falling off due to the bending of the hollow metal conduit 3.

[0030] According to Figure 4As shown in the figure, during polishing, the workpiece 5 to be processed is fixed on the machine tool workbench. The positive pole of the power supply 9 is connected to the workpiece 5 to be processed, and the negative pole of the power supply 9 is connected to the octopus-antenna-structure electrode 1. The octopus-antenna-structure electrode 1 is placed inside the workpiece 5 to be processed, and both ends of the octopus-antenna-structure electrode are clamped by the first spindle fixture 7 and the second spindle fixture 8 of the machine tool. Through the internal channel of the fixture, internal flushing is carried out inside the octopus-antenna-structure electrode 1. Due to the different fluid pressures inside and outside the octopus-antenna-structure electrode 1, the internal electrolyte is injected into the internal hole cavity of the workpiece 5 to be processed through the hollow structure inside the bionic suction cup unit 2. The electrolyte in the hole cavity comes into full contact with the surface 4 of the internal channel of the workpiece to be processed, and an electrochemical reaction occurs to achieve polishing. After the electrochemical reaction ends, electrolytic waste liquid is generated, and the newly injected electrolyte flushes out the electrolytic waste liquid from the inner cavity of the workpiece 5 to be processed, realizing internal flushing and external discharge. The external flushing flushes out the electrolytic waste liquid, and the electrolytic waste liquid is collected through the liquid collection cavity 6 for waste liquid recovery. A circulation system 10 is set up to purify and cool the electrolytic waste liquid, and the electrolyte is recycled to achieve sustainable electrochemical processing.

[0031] According to Figure 5 As shown in the figure, the hollow metal conduit of the present invention can modify the shape of the hollow metal conduit according to the morphology of the internal channel of the workpiece to be processed, and circular and elliptical metal conduits can be designed. The elliptical metal conduit can utilize the characteristic that the curvature of the long-axis endpoints is relatively large to carry out electrochemical processing on workpieces with internal channels having nearly right angles. The number of channels on the plane where the long-axis endpoints of the elliptical metal conduit are located is relatively more than that on other planes, which can ensure that the processing efficiency on the plane where the long-axis endpoints are located is the same as that on other planes, and avoid poor local processing effects.

Claims

1. An octopus tentacle structure electrode, characterized in that: The octopus tentacle-like structure electrode (1) is a hollow metal conduit (3) whose wall is provided with radial through grooves distributed at equal angles and evenly distributed in an array along the axial direction, so that it has good flexibility; the bionic suction cup unit (2) is made of rubber material and is embedded in the radial through groove through a detachable structure; Wherein, the bionic suction cup unit (2) comprises: The stepped boss (2-1) has an inner diameter d satisfying the relationship: d=0.8D (D is the outer diameter of the boss). The boss (2-1) has a certain height, which can effectively prevent the metal conduit (3) and the inner channel surface (4) of the workpiece to be processed from directly contacting each other during processing to cause short circuit burns. The central through hole (2-2) has a hole diameter of 0.2-0.3d, which is connected to the inner cavity of the hollow metal conduit (3) for positioning, and at the same time enables the octopus tentacle structure electrode (1) to discharge the internal electrolyte more evenly during processing. The annular insulating inner skirt (2-3) is buckled inside the inner surface of the electrode to fix it.

2. The octopus tentacle-like structure electrode according to claim 1, characterized in that: The distribution density of the bionic suction cup unit (2) is adjustable, and the height of the stepped boss can be adaptively adjusted as the diameter and curvature of the inner hole of the workpiece to be processed change; the hollow metal conduit (3) can be made into a circular or elliptical shape according to the shape of the inner channel.

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