Electrolysis discharge milling cathode device utilizing motion alternating magnetic field to assist arc breaking

Abstract

The invention discloses an electrolysis discharge milling machining cathode device utilizing a motion alternating magnetic field to assist arc breaking. The electrolysis discharge milling machining cathode device comprises a cathode rod, an insulation sleeve cover, a magnetic ring and a cathode head. The cathode rod is of a hollow structure and is used for conveying electrolyte; a shaft shoulder structure is arranged on the lower portion of the cathode rod and connected with the cathode head through a spring. The insulating sleeve cover is provided with an annular groove for embedding the magnetic ring, the magnetic ring is formed by circumferentially splicing a plurality of axially magnetized fan-shaped magnets, and N-S poles are alternately arranged. The cathode head is of a hollow structure and is in clearance fit with the cathode rod, liquid outlet holes are evenly distributed in the bottom and the side wall, and an external thread connector is arranged at the top end and assembled on the insulation sleeve cover. During machining, the cathode device rotates, the magnetic ring forms a rotating alternating magnetic field above a workpiece machining area, the movement direction of charged particles in an electric arc is disturbed, and arc breaking is accelerated. Modularized assembly is adopted, rapid disassembly, assembly and maintenance are facilitated, the maintenance cost is reduced, and the machining efficiency and the workpiece surface quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical discharge composite machining, and particularly to a cathode device for electrochemical discharge milling machining assisted by a moving alternating magnetic field to break arcs. Background Art

[0002] With the continuous improvement of the requirements for the reliability and energy consumption rate of structural parts in the aerospace field, integration and lightweight have become the two core trends in the development of structural parts in this field. Titanium alloys, superalloys, and metal matrix composites have become the preferred materials for manufacturing key structural parts of aircraft due to their excellent comprehensive properties, including high strength, high thermal strength, and corrosion resistance. However, the high-strength characteristics of these materials also pose significant technical challenges to processing equipment and processes during machining.

[0003] When traditional machining methods are used to process these high-strength materials, a large cutting force needs to be applied, which not only causes the workpiece to be prone to deformation but also, due to severe work hardening, increases the accumulation of cutting heat, exacerbates tool wear, and further leads to workpiece deformation and surface defects. Electrochemical milling machining technology, as a combination of electrochemical machining and numerical control technology, removes materials by anodic oxidation dissolution, avoiding the generation of cutting force and being particularly suitable for machining difficult-to-cut metal materials such as titanium alloys. However, the low material removal rate of this technology limits its application in the efficient production of aerospace structural parts.

[0004] The electrochemical discharge composite milling machining technology combines the advantages of electrochemical milling and discharge machining, and further improves the machining efficiency through intermittent discharge on the basis of electrochemical machining. During this process, electrochemical machining erodes part of the anode material and forms a hydrogen film on the cathode end face, creating conditions for discharge machining. When the electric field and gas film in the machining gap meet the discharge breakdown conditions, discharge occurs, melting or vaporizing the anode material using the instantaneous high temperature and high pressure, thereby achieving efficient material removal.

[0005] However, during the direct current electrochemical discharge composite milling machining process, the generation of continuous arcs will lead to an increase in electrode loss and a decrease in the surface quality of the workpiece. Currently, mainly by means of cathode rotation combined with high-speed flushing between electrodes to forcibly break the discharge channel. However, when increasing the cathode feed rate, the discharge energy increases, and it is easier to form a stable arc, and the above method is difficult to achieve rapid arc breaking. Therefore, how to accelerate the arc breaking process, reduce electrode loss, and improve the machining surface quality while improving the machining efficiency has become a key issue in the popularization and application of the electrochemical discharge composite milling machining technology. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this section, the abstract, and the title, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] Therefore, to solve the above technical problems, the present invention provides the following technical solution: an electro-discharge milling cathode device using a moving alternating magnetic field to assist in arc breaking, comprising a cathode rod, an insulating sleeve cover, a magnetic ring, and a cathode head;

[0008] The cathode rod is of a hollow structure, and the inner cavity of the cathode rod is provided as an axial hole, which penetrates the upper and lower end faces for electrolyte delivery; a shoulder structure is provided at the lower part of the cathode rod, and a spring is sleeved on the cathode rod at the bottom of the shoulder structure. The top end of the spring is connected to the lower surface of the shoulder structure, and the bottom end of the spring is connected to the upper end face of the cathode head;

[0009] The insulating sleeve cover is provided with an annular groove for embedding the magnetic ring, the magnetic ring is embedded in the annular groove, and the insulating sleeve cover embedded with the magnetic ring is pressed above the shoulder structure of the cathode rod; a threaded blind hole with an upward opening is provided at the center of the insulating sleeve cover for connecting the cathode head;

[0010] The magnetic ring is formed by circumferentially splicing a plurality of axially magnetized sector magnets, and the end face magnetic poles of adjacent sector magnets are arranged alternately as N-S poles;

[0011] The cathode head is of a hollow structure, the inner hole of the cathode head is in clearance fit with the lower part of the cathode rod, and liquid outlet holes are evenly distributed on the bottom and side walls of the cathode head; an external threaded joint is arranged at the top end of the cathode head, and the external threaded joint is assembled in the threaded blind hole of the insulating sleeve cover.

[0012] As a preferred scheme of the electro-discharge milling cathode device using a moving alternating magnetic field to assist in arc breaking according to the present invention, wherein: the insulating sleeve cover is made of an engineering plastic with electrolytic insulation properties (such as polyether ether ketone (PEEK)).

[0013] As a preferred scheme of the electro-discharge milling cathode device using a moving alternating magnetic field to assist in arc breaking according to the present invention, wherein: the insulating sleeve cover embedded with the magnetic ring is pressed above the shoulder structure of the cathode rod.

[0014] As a preferred scheme of the electro-discharge milling cathode device using a moving alternating magnetic field to assist in arc breaking according to the present invention, wherein: the cathode head is made of graphite or copper-tungsten alloy material, which is convenient for timely replacement after wear.

[0015] As a preferred embodiment of the cathode device for electro - discharge milling using a moving alternating magnetic field to assist in arc interruption according to the present invention, wherein: the liquid outlet holes on the circumferential outer wall of the cathode head are distributed in layers along the axial direction, and the liquid outlet holes in each layer are equally spaced along the circumferential direction of the circumferential outer wall of the cathode head.

[0016] As a preferred embodiment of the cathode device for electro - discharge milling using a moving alternating magnetic field to assist in arc interruption according to the present invention, wherein: during machining, as the cathode device rotates, the magnetic poles formed by the magnetic ring above the machining area of the workpiece continuously change direction, generating a rotating alternating magnetic field in the vertical direction to disrupt the movement direction of charged particles in the arc and accelerate the arc interruption process.

[0017] Advantages of the present invention:

[0018] 1. The present invention adopts a modular assembly structure. The quick disassembly and assembly are realized through the threaded connection between the insulating sleeve cover and the cathode head. The spring pre - tightening mechanism is used to ensure reliable contact between components, which not only significantly improves the maintenance efficiency, but also facilitates the timely replacement of worn - out parts, reduces the maintenance cost, and extends the service life of the device.

[0019] 2. The present invention integrates the magnetic field generating device inside the rotating cathode through an innovative magnetic ring inlay structure. The automatic switching of the magnetic field direction is realized by the rotation of the cathode itself without an additional driving device, which simplifies the system structure. The rotating alternating magnetic field effectively disrupts the movement direction of charged particles in the arc, accelerates the arc interruption process, thereby reducing electrode wear and improving the machining efficiency and the surface quality of the workpiece.

[0020] 3. The cathode head in the present invention adopts a replaceable design. The quick replacement of different materials and different nozzle (liquid outlet hole) structures is realized through a standardized interface, which not only facilitates the timely replacement of worn - out parts and reduces the maintenance cost, but also can flexibly adjust the structure of the cathode head according to the machining requirements, improving the machining efficiency and the surface quality of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. Among them:

[0022] Figure 1 is the overall structure schematic diagram of the present invention.

[0023] Figure 2 is the exploded structure schematic diagram of the present invention.

[0024] Figure 3 is the structure schematic diagram of the machining system of the cathode device of the present invention.

[0025] Figure 4 This is a schematic structural diagram of the cathode device of the present invention showing the changes in the magnetic field and the force direction on the arc during rotation.

[0026] In the figure: 100, cathode rod; 101, axial center hole; 102, shaft shoulder structure; 103, spring;

[0027] 200, insulating sleeve cover; 201, annular groove; 202, threaded blind hole;

[0028] 300, magnetic ring;

[0029] 400, cathode head; 401, liquid outlet hole; 402, external thread joint;

[0030] 500, workpiece. Specific embodiments

[0031] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings of the specification.

[0032] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0033] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that can be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that mutually excludes other embodiments.

[0034] Thirdly, the present invention is described in detail with reference to the schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0035] Referring to Figures 1 to 4 , for an embodiment of the present invention, there is provided an electro-discharge milling cathode device using a moving alternating magnetic field to assist in arc breaking, including a cathode rod 100, an insulating sleeve cover 200, a magnetic ring 300, and a cathode head 400;

[0036] The cathode rod 100 is designed as a hollow structure, and its inner cavity is defined as the axial hole 101. The axial hole 101 penetrates through the upper and lower end faces of the cathode rod 100 for the transportation of electrolyte. At the lower part of the cathode rod 100, a shoulder structure 102 is constructed. At the bottom of the shoulder structure 102, a spring 103 is sleeved on the cathode rod 100. The top end of the spring 103 is tightly connected to the lower surface of the shoulder structure 102, and its bottom end is connected to the upper end face of the cathode head 400 to ensure the stable floating of the cathode head 400 during the processing.

[0037] The insulating sleeve cover 200 is made of an engineering plastic material with electrolytic insulation properties (such as polyetheretherketone (PEEK)) to ensure its durability and safety in the electrolyte environment. An annular groove 201 is opened on the insulating sleeve cover for embedding the magnetic ring 300. After the magnetic ring 300 is embedded, the lower part of the insulating sleeve cover 200 is clamped above the shoulder structure 102 of the cathode rod 100 to ensure the stability of the structure. A threaded blind hole 202 with an upward opening is provided at the center of the insulating sleeve cover 200 for connecting with the cathode head 400.

[0038] The magnetic ring 300 is formed by circumferentially splicing multiple axially magnetized sector magnets. The magnetic poles of adjacent magnets are opposite, that is, the end face magnetic poles of adjacent sector magnets are arranged alternately as N-S poles. Such a design enables the magnetic ring 300 to form a magnetic pole with continuously changing directions above the processing area of the workpiece 500 when the cathode device rotates, thereby generating a rotating alternating magnetic field in the vertical direction. As Figure 4 shown, the rotating alternating magnetic field generates an alternating Lorentz force on the charged particles in the arc, disturbing the movement direction of the particles and making it difficult for the arc to maintain stability, thus achieving efficient arc breaking.

[0039] The cathode head 400 is also a hollow structure. Its inner hole is in clearance fit with the lower part of the cathode rod 100, allowing the cathode head 400 to have a certain floating space under the action of the spring. The bottom and side walls of the cathode head 400 are evenly distributed with liquid outlet holes 401. These liquid outlet holes 401 are arranged in layers along the axial direction on the circumferential outer wall of the cathode head 400, and each layer of liquid outlet holes is evenly spaced circumferentially along the circumferential outer wall of the cathode head 400, optimizing the distribution and flow of the electrolyte and improving the processing efficiency. An external threaded joint 402 is arranged at the top end of the cathode head 400, and this joint is assembled in the threaded blind hole 202 of the insulating sleeve cover 200 to achieve the stable connection between the two. The cathode head 400 is made of graphite or copper-tungsten alloy material, which has good electrical conductivity, corrosion resistance and electric erosion resistance, and can be quickly replaced after being worn, extending the service life of the device.

[0040] As Figure 3As shown in the figure, the machining system consists of a cathode device, a power supply, and a workpiece 500; the cathode rod 100 is connected to the negative pole of the power supply, and the workpiece 500 is connected to the positive pole of the power supply; during machining, the workpiece 500 rotates and feeds forward, and the cathode device erodes materials through electrolytic discharge. As the cathode device rotates, the magnetic ring 300 forms a rotating alternating magnetic field above the machining area of the workpiece 500, generating a periodic Lorentz force perturbation on the charged particles in the arc, disturbing the particle movement trajectory, and accelerating the arc-breaking process. At the same time, the liquid outlet hole 401 of the cathode head 400 sprays high-speed electrolyte, further assisting in arc-breaking and discharging the electrolytic products in the machining area, ensuring the stability and efficiency of the machining process.

[0041] The cathode device of the present invention realizes the following technical effects by integrating the moving alternating magnetic field-assisted arc-breaking technology:

[0042] Efficient arc-breaking: The combined action of the rotating alternating magnetic field and the high-speed electrolyte spraying significantly shortens the arc maintenance time and improves the machining efficiency;

[0043] Low loss: The alternating magnetic field perturbation reduces the arc thermal influence, reduces the loss of the cathode head 400, and extends the service life;

[0044] High surface quality: The dynamic magnetic field promotes the discharge of electrolytic products, avoids short-circuit phenomena, and improves the surface quality of the workpiece;

[0045] Process adaptability: The modular design facilitates the rapid replacement of the cathode head 400 to adapt to different materials and machining requirements.

[0046] In summary, the present invention solves the problems in traditional electrolytic discharge milling machining, such as difficult and rapid arc-breaking, large electrode loss, and poor surface quality, through innovative structural design and magnetic field-assisted arc-breaking mechanism, realizing efficient, stable, and low-loss electrolytic discharge composite milling machining, which is particularly suitable for the efficient and precision machining of difficult-to-machine materials in the aerospace field.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking, characterized in that: It comprises a cathode rod (100), an insulating cover (200), a magnetic ring (300) and a cathode head (400); The cathode rod (100) is a hollow structure, the inner cavity of the cathode rod (100) is arranged as an axial hole (101), and the axial hole (101) passes through the upper and lower end surfaces for electrolyte transportation; the lower part of the cathode rod (100) is provided with a shoulder structure (102), and a spring (103) is sleeved on the cathode rod (100) at the bottom of the shoulder structure (102), the top end of the spring (103) is connected to the lower surface of the shoulder structure (102), and the bottom end of the spring (103) is connected to the upper end surface of the cathode head (400); The insulating sleeve (200) is provided with an annular groove (201) for embedding the magnetic ring (300), the magnetic ring (300) is embedded in the annular groove (201), and the insulating sleeve (200) embedded with the magnetic ring (300) is clamped on the upper side of the shoulder structure (102) of the cathode rod (100); the center of the insulating sleeve (200) is provided with a threaded blind hole (202) with an opening facing upwards, which is used for connecting the cathode head (400); The magnetic ring (300) is formed by circumferentially splicing a plurality of axially magnetized sector-shaped magnets, and the end surface magnetic poles of adjacent sector-shaped magnets are alternately arranged in the form of NS poles; The cathode head (400) is a hollow structure, the inner hole of the cathode head (400) is in clearance with the lower part of the cathode rod (100), and the bottom and side walls of the cathode head (400) are evenly distributed with liquid outlet holes (401); the top of the cathode head (400) is arranged with an external threaded joint (402), and the external threaded joint (402) is assembled in the threaded blind hole (202) of the insulating cover (200).

2. The cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking as claimed in claim 1, characterized in that: The insulating sleeve cover (200) is made of engineering plastics having electrolytic insulation properties.

3. The cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking as claimed in claim 1, characterized in that: The insulating sleeve cover (200) embedded in the magnetic ring (300) is clamped on the upper side of the shaft shoulder structure (102) of the cathode rod (100).

4. The cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking as claimed in claim 1, characterized in that: The cathode head (400) is made of graphite or copper-tungsten alloy material, and is easy to replace in time after being worn out.

5. The cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking as claimed in claim 1, characterized in that: The liquid outlet holes (401) on the circumferential outer wall of the cathode head (400) are distributed in layers along the axial direction, and the liquid outlet holes (401) in each layer are distributed at equal intervals along the circumferential outer wall of the cathode head (400).

6. The cathode device for electrolytic milling machining using a moving alternating magnetic field to assist arc breaking as claimed in claim 1, characterized in that: During processing, as the cathode device rotates, the magnetic poles formed by the magnetic ring (300) above the processing area of ​​the workpiece (500) continuously switch directions, generating a rotating alternating magnetic field in a vertical direction to disrupt the movement direction of charged particles in the arc and accelerate the arc breaking process.

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