CN106238838A - Method for electrochemically machining ellipsoidal bamboo joint hole - Google Patents

Abstract

A method for electrochemically machining an ellipsoidal bamboo hole comprises the following steps: 1) preparing a tool electrode A; 2) preparing a tool electrode B; 3) machining a circular bamboo hole; firstly feeding the tool electrode A into a pre-machined light hole on a workpiece to be machined, and then flowing the electrolyte from bottom to top along the gap between the tool electrode A and the inner wall of the light hole on the workpiece to be machined, and the surface of the workpiece to be machined is removed under the action of the electric field to form a circular bamboo hole; 4) machining an ellipsoidal bamboo hole: taking out the tool electrode A in step 3), inserting the tool electrode B into the circular bamboo hole, and driving the tool electrode B to swing back and forth along the circumferential direction at a set angle through the machine tool spindle, and the inner wall surface of the circular bamboo hole in the electrolytic machining area is subjected to secondary electrolytic machining, and the circular bamboo hole gradually forms an ellipsoidal bamboo hole. The present invention can machine a small aperture size, and the surface performance of the machined workpiece will not be affected by the cutting force.

Description

A Method for Electrochemically Machining Ellipsoidal Slub Holes

technical field

The invention relates to the field of electrochemical machining, in particular to a method for electrochemically machining ellipsoidal bamboo joint holes.

Background technique

With the progress of society and the development of science and technology, in modern aerospace, automobile, machine tool and other manufacturing industries, for parts that are subjected to severe stress and heat during use, in order to reduce the deformation of parts caused by incomplete cooling and prolong their use More and more non-circular special-shaped cross-sections are used, that is, the cross-section is not circular, but non-circular shapes such as ellipse, variable ellipse, and cycloid. For example, the special-shaped pin hole design commonly used in the modern piston manufacturing industry can avoid elastic deformation under high combustion pressure, alleviate the problem of stress concentration inside the pin hole, and enable the piston to obtain better performance. In addition, the use of non-circular raceways in aero-engine roller bearings can effectively solve the phenomenon of roller slippage at high speed and light load, and avoid destructive effects on the engine. These non-circular special-shaped cross-section parts have high requirements on manufacturing and processing technology because of their complex shape and processing accuracy.

At present, the machining methods of non-circular special-shaped cross-section parts are mostly realized through the synthesis of the rotary motion of the spindle and the radial telescopic motion of the cutting tool. However, there are various problems in actual processing, mainly because there are problems such as small installation space and high difficulty in implementing control and measurement when installing high-frequency micro-feeding mechanism and control drive device on the rotary boring bar.

Contents of the invention

In order to overcome the deficiencies in the prior art, the present invention provides a method for electrochemically machining ellipsoidal bamboo-shaped holes, which uses the principle of electrochemical dissolution of metal materials in the state of electricity, and uses specially designed tool electrodes to control Processing time, processing voltage, and the swing of the tool electrode realize the processing of the ellipsoidal microstructure on the small-aperture surface.

The technical solution adopted by the present invention to solve its technical problems is:

A method for electrochemically machining ellipsoidal bamboo joint holes, said method comprising the following steps:

1) Preparation of tool electrode A:

The surface of a smooth cylindrical metal wire or metal tube is made into annular grooves at equal intervals along the circumferential direction, and then insulating material is coated and cured in the annular grooves to form a bamboo joint with metal conductive parts and insulating parts spaced apart from each other Shaped tool electrode A;

2) Preparation of tool electrode B:

The surface of a smooth cylindrical metal wire or metal tube is made into planes parallel to each other along the front and rear sides of the axial direction, and arc-shaped grooves are made at equal intervals on the left and right sides of the axial direction, and then the arc-shaped grooves and the front and rear Insulating material is coated on two parallel planes and cured to form a tool electrode B in which the front and rear sides are insulated, and the metal conductive parts on the left and right sides are spaced from the insulating part; wherein, two adjacent arcs on the tool electrode B The interval between the grooves is the same as the distance between two adjacent annular grooves on the tool electrode A, and the upper and lower widths of the annular grooves on the tool electrode A are the same as the upper and lower widths of the arc-shaped grooves on the tool electrode B , the radius of the cross-section of the metal conducting part of the tool electrode B is the same as the radius of the cross-section of the metal conducting part of the tool electrode A;

3) Processing of circular slub holes:

First feed the tool electrode A into the pre-processed light hole on the workpiece to be processed, and then flow the electrolyte from bottom to top along the gap between the tool electrode A and the inner wall of the light hole on the workpiece to be processed, and then The workpiece to be processed is connected to the positive pole of the power supply, and the tool electrode A is connected to the negative pole of the power supply. An electrolytic machining zone is formed between the workpiece to be processed surrounded by the electrolyte and the metal conductive part of the tool electrode A. The surface of the workpiece to be processed is removed under the action of an electric field to form a circle. shaped bamboo hole;

4) Processing of ellipsoidal bamboo joint holes:

Take out the tool electrode A in step 3), insert the tool electrode B into the circular slub hole, and the metal conductive part and the insulating part of the tool electrode B are aligned with the metal conductive part and the insulating part of the tool electrode A in the axial direction. Correspondingly, at the same time, the insulating layers on the front and rear sides of the tool electrode B are arranged front and back; the machining voltage and energization time of the electrolyte are set, and the tool electrode B is driven to reciprocate along the circumferential direction by the machine tool spindle at a set angle, and the circular bamboo joint The inner wall surface of the hole in the electrolytic processing area is subjected to secondary electrolytic processing, and the circular slub hole gradually forms an ellipsoidal slub hole. When the set electrification time is reached, the circular slub hole completely forms an ellipsoidal slub hole;

Wherein, the setting angle of the reciprocating swing of the tool electrode B is 30°-60°.

Further, in the step 1) preparation of the tool electrode A;

The surface of a smooth cylindrical metal wire or metal tube is coated with a layer of insulating glue at equal intervals along the circumferential direction, and cured under ultraviolet light, and then immersed in an electrolyte solution with a mass concentration of 10% NaNO ₃ Electrolytic corrosion, connect the cylindrical metal wire or metal pipe coated with insulating glue to the positive pole of the power supply, and the iron sheet in the electrolyte solution with a mass concentration of 10% NaNO ₃ to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical metal wire or a metal tube, so that the metal material on the exposed part of the cylindrical wire or metal tube surface is corroded into an annular groove shape, and then the previously coated layer of insulating glue is removed to form the metal conductive part of the tool electrode A. A photosensitive resin containing 15% SiC was evenly coated in the corroded annular groove and cured under ultraviolet light irradiation, and the photosensitive resin layer in the annular groove formed the insulating part of the tool electrode A, thereby producing the tool electrode A.

Further, the step 2) is in the preparation of the tool electrode B;

Stretch the surface of a smooth cylindrical metal wire or metal tube along the left and right sides of the axis, coat a layer of insulating glue and cure it under ultraviolet light, and then infiltrate it into a prepared mass concentration of 10% NaNO ₃ In the electrolyte, connect the cylindrical metal wire or metal tube coated with insulating glue to the positive pole of the power supply, and connect the iron sheet in the electrolyte with a mass concentration of ₁₀ % NaNO3 to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical Metal wire or metal tube, so that the metal material of the exposed part of the surface of the cylindrical metal wire or metal tube is corroded, and the front and rear sides of the axial direction form parallel planes, and 15% SiC photosensitive resin is coated on the plane, and Curing under ultraviolet light to obtain metal wires or metal tubes insulated on the front and rear sides of the axial direction;

Then, coat a layer of insulating glue on the left and right sides of the axially left and right sides of the insulated metal wire or metal tube at equal intervals, and cure it under ultraviolet light. After curing, immerse it in a concentration of 10% Electrolytic corrosion is carried out in the _NaNO3 electrolyte, and the cylindrical metal wire or metal tube insulated on the front and rear sides is connected to the positive pole of the power supply. The iron sheet in the NaNO3 electrolyte with a mass concentration of ₁₀ % is connected to the negative pole of the power supply. After the electrolytic corrosion reaches the set time , take out the metal wire or metal tube, so that the metal material on the exposed part of the metal wire or metal tube surface is corroded into an arc-shaped groove, and then remove the previously coated layer of insulating glue to form the metal conductive part of the tool electrode B, Finally, a photosensitive resin containing 15% SiC is evenly coated in the corroded arc-shaped groove and cured under ultraviolet light. The photosensitive resin layer in the arc-shaped groove forms the insulating part of the tool electrode B, thereby making the tool Electrode B.

The main beneficial effects of the present invention are: the processing of non-circular cross-section cooling holes in the circumferential direction can be realized; the processing process is simple; in the case of array electrodes, multi-hole processing can be performed at one time, and the efficiency is high; the processing accuracy is high, and the size of the processable aperture is small , The surface properties of the processed workpiece will not be affected by the cutting force.

Description of drawings

Fig. 1a is a schematic structural diagram of a metal wire whose surface is in the shape of an annular groove.

Fig. 2a is a schematic structural view of the tool electrode A made in Fig. 1a.

Fig. 1b is a schematic structural view of a metal tube with an annular groove on its surface.

Fig. 2b is a schematic structural diagram of the tool electrode A2 made in Fig. 1b.

Fig. 3 is a schematic diagram of the structure of a metal wire whose axially front and rear sides are corroded into flat surfaces, and whose axially left and right sides are corroded into arc-shaped grooves.

FIG. 4 is a schematic structural view of the tool electrode B made in FIG. 3 .

Fig. 5 is a schematic diagram of the electrolytic machining of ellipsoidal bamboo joint holes.

FIG. 6 is a longitudinal sectional view of a circular slub hole processed by a tool electrode A. FIG.

Fig. 7 is a front view of Fig. 6 .

Fig. 8 is a schematic diagram of the tool electrode B periodically oscillating axially and circumferentially in the circular slub hole.

Fig. 9 is a longitudinal sectional view of an ellipsoidal bamboo joint hole.

Fig. 10 is a front view of Fig. 9 .

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 to 10, a method for electrochemically machining ellipsoidal bamboo joint holes, the method includes the following steps:

2) Preparation of tool electrode A:

The surface of a smooth cylindrical metal wire or metal tube is made into annular grooves at equal intervals along the circumferential direction, and then insulating material is coated and cured in the annular grooves to form a bamboo joint with metal conductive parts and insulating parts spaced apart from each other Shaped tool electrode A;

3) Preparation of tool electrode B:

The surface of a smooth cylindrical metal wire or metal tube is made into planes parallel to each other along the front and rear sides of the axial direction, and arc-shaped grooves are made at equal intervals on the left and right sides of the axial direction, and then the arc-shaped grooves and the front and rear Insulating material is coated on two parallel planes and cured to form a tool electrode B in which the front and rear sides are insulated, and the metal conductive parts on the left and right sides are spaced from the insulating part; wherein, two adjacent arcs on the tool electrode B The interval between the grooves is the same as the distance between two adjacent annular grooves on the tool electrode A, and the upper and lower widths of the annular grooves on the tool electrode A are the same as the upper and lower widths of the arc-shaped grooves on the tool electrode B , the radius of the cross-section of the metal conducting part of the tool electrode B is the same as the radius of the cross-section of the metal conducting part of the tool electrode A;

3) Processing of circular slub holes:

First feed the tool electrode A into the pre-processed optical hole on the workpiece 6 to be processed, and then flow the electrolyte along the gap between the tool electrode A and the inner wall of the optical hole on the workpiece 6 from bottom to top, Then the workpiece to be processed is connected to the positive pole of the power supply, and the tool electrode A is connected to the negative pole of the power supply. An electrolytic machining zone is formed between the workpiece 6 surrounded by the electrolyte and the metal conductive part of the tool electrode A, and the surface of the workpiece 6 to be processed is under the action of an electric field. Removed to form a circular slub hole;

4) Processing of ellipsoidal bamboo joint holes:

Take out the tool electrode A in step 3), insert the tool electrode B into the circular slub hole, and the metal conductive part and the insulating part of the tool electrode B are aligned with the metal conductive part and the insulating part of the tool electrode A in the axial direction. Correspondingly, at the same time, the insulating layers on the front and rear sides of the tool electrode B are arranged front and back; the machining voltage and energization time of the electrolyte are set, and the tool electrode B is driven to reciprocate along the circumferential direction by the machine tool spindle at a set angle, and the circular bamboo joint The inner wall surface of the hole in the electrolytic processing area is subjected to secondary electrolytic processing, and the circular slub hole gradually forms an ellipsoidal slub hole. When the set electrification time is reached, the circular slub hole completely forms an ellipsoidal slub hole;

Wherein, the setting angle of the reciprocating swing of the tool electrode B is 30°-60°.

Further, in the step 1) preparation of the tool electrode A;

The surface of a smooth cylindrical metal wire or metal tube is coated with a layer of insulating glue at equal intervals along the circumferential direction, and cured under ultraviolet light, and then immersed in an electrolyte solution with a mass concentration of 10% NaNO ₃ Electrolytic corrosion, connect the cylindrical metal wire or metal pipe coated with insulating glue to the positive pole of the power supply, and the iron sheet in the electrolyte solution with a mass concentration of 10% NaNO ₃ to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical metal wire or a metal tube, so that the metal material on the exposed part of the cylindrical wire or metal tube surface is corroded into an annular groove shape, and then the previously coated layer of insulating glue is removed to form the metal conductive part 1 of the tool electrode A, and finally in the The corroded annular groove 2 is evenly coated with a photosensitive resin containing 15% SiC and cured under ultraviolet light irradiation. The photosensitive resin layer 3 in the annular groove 2 forms the insulating part of the tool electrode A, thereby making the tool electrode a.

Further, the step 2) is in the preparation of the tool electrode B;

Stretch the surface of a smooth cylindrical metal wire or metal tube along the left and right sides of the axis, coat a layer of insulating glue and cure it under ultraviolet light, and then infiltrate it into a prepared mass concentration of 10% NaNO ₃ In the electrolyte, connect the cylindrical metal wire or metal tube coated with insulating glue to the positive pole of the power supply, and connect the iron sheet in the electrolyte with a mass concentration of ₁₀ % NaNO3 to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical Metal wire or metal tube, so that the metal material of the exposed part of the surface of the cylindrical metal wire or metal tube is corroded, and the front and rear sides of the axial direction form a plane 4 parallel to each other, and 15% SiC photosensitive resin is coated on the plane 4 , and cured under ultraviolet light to obtain a metal wire or a metal tube insulated on the front and rear sides of the axial direction;

Then, coat a layer of insulating glue on the left and right sides of the axially left and right sides of the insulated metal wire or metal tube at equal intervals, and cure it under ultraviolet light. After curing, immerse it in a concentration of 10% Electrolytic corrosion is carried out in the _NaNO3 electrolyte, and the cylindrical metal wire or metal tube insulated on the front and rear sides is connected to the positive pole of the power supply. The iron sheet in the NaNO3 electrolyte with a mass concentration of ₁₀ % is connected to the negative pole of the power supply. After the electrolytic corrosion reaches the set time , take out the metal wire or metal tube, so that the metal material on the exposed part of the metal wire or metal tube surface is corroded into an arc-shaped groove, and then remove the previously coated layer of insulating glue to form the metal conductive part of the tool electrode B, Finally, a photosensitive resin containing 15% SiC is evenly coated in the corroded arc-shaped groove 5 and cured under ultraviolet light irradiation, and the photosensitive resin layer 3 in the arc-shaped groove 5 forms the insulating part of the tool electrode B, thereby Tool electrode B was prepared.

Of course, the metal wire/tube whose surface is corroded into an annular groove can be obtained by other processing methods, such as 3D printing, turning, and then further coated with insulating materials such as photosensitive resin on the annular groove to obtain the tool electrode A The metal wires/tubes that are corroded into planes on the front and rear sides of the axial direction and arc-shaped grooves on the left and right sides of the axial direction can be obtained by other processing methods, such as 3D printing, turning, and then further processed in the axial direction. The front and rear sides and the arc-shaped groove are coated with insulating materials such as photosensitive resin to obtain the tool electrode B.

Electrolytic machining principle of the present invention is:

The electrolyte flows from bottom to top along the gap between the tool electrode A and the side wall of the light hole of the workpiece 6 to be processed. The workpiece 6 to be processed is connected to the positive pole of the power supply, and the tool electrode A is connected to the negative pole. The workpiece 6 to be processed and the tool electrode surrounded by the electrolyte The electrolytic machining zone is formed between the metal conductive parts of A, and the surface material of the workpiece is removed under the action of the electric field. According to the electric field distribution around the tool electrode A, the electric field intensity of the metal conductive part facing the tool electrode A presents a symmetrical arc, so it is in the tool The corrosion rate of the surface material of the workpiece near the exposed metal material of the cathode of electrode A shows the law of fast in the middle and slow on both sides. Finally, the light hole is processed into a circular bamboo hole, that is, the cross section of the bamboo hole is a circular section 8; after that, the tool The electrode A is taken out, and the tool electrode B10 is inserted at the corresponding position, and the secondary electrolytic machining is performed again. Since the front and rear sides of the tool electrode B are coated with an insulating material containing 15% SiC photosensitive resin, the processed round-section bamboo Only a part of the inner side of the knot hole is electrolytically corroded again. During the electrolytic machining process of the tool electrode B10, the tool electrode B10 is driven to a certain angle by controlling the spindle of the machine tool. Processing voltage and electrification time, control the circular slub hole in the inner wall of the electrolytic processing area to be further corroded, the circular slub hole gradually forms an ellipsoidal slub hole, and the cross section of the ellipsoidal slub hole is elliptical9 .

Example one:

1. Preparation of tool electrodes.

The tool electrode 7 includes a tool electrode A and a tool electrode B;

Preparation of tool electrode A: Take a cylindrical metal wire with a diameter of 1.5mm and a length of 60mm, and apply insulating glue evenly along the circumferential direction at a certain distance, that is, at equal intervals such as 5mm, and cure it under ultraviolet light, and then fix it On the machine tool, the feed is immersed in a ₁₀ % NaNO3 electrolyte, the cylindrical wire coated with insulating glue is connected to the positive electrode of the power supply, and the iron sheet in the ₁₀ % NaNO3 electrolyte is connected to the power supply Negative electrode, apply a voltage of 8V, take out the metal wire after 5 minutes of working time, remove the insulating glue on the surface of the wire, and form the metal conductive part of the tool electrode A to obtain the tool electrode A substrate; then corrode the ring on the metal surface of the tool electrode A substrate The groove is coated with a photosensitive resin containing 15% SiC, and is cured under an ultraviolet light curing machine for 3 minutes to form an insulating part of the tool electrode A, that is, the tool electrode A is prepared.

Preparation of tool electrode B: Take a cylindrical metal wire with a diameter of 1.5 mm and a length of 60 mm, stretch it straight along the left and right sides of its axis, apply insulating glue and cure it, then fix the wire on the machine tool, and feed it to the equipped In the ₁₀ % NaNO3 electrolyte, connect the cylindrical metal wire or metal pipe coated with insulating glue to the positive pole of the power supply, and the iron sheet in the electrolyte with a mass concentration of ₁₀ % NaNO3 is connected to the negative pole of the power supply, and add a working voltage of 8V. Take out the metal wire after 5 minutes; coat the photosensitive resin containing 15% SiC on the front and rear sides of the metal wire that have been corroded, and cure it under a UV curing machine for 3 minutes, and take it out at equal intervals such as 5mm along the circumferential direction after cooling down Evenly coat the insulating glue and cure it, and immerse it in the electrolyte solution with a mass concentration of ₁₀ % NaNO3 for the second time for electrolytic corrosion. Since the front and rear sides of the metal wire are protected by photosensitive resin insulation, only the metal of the metal wire will be corroded during the electrolysis process The exposed part gradually forms an arc-shaped groove. Apply a voltage of 8V. After 5 minutes of working time, take out the metal wire and evenly coat the photosensitive resin containing 15% SiC in the arc-shaped groove, and cure it under a UV curing machine for 3 minutes. That is, the tool electrode B is prepared.

2. Processing of ellipsoidal bamboo joint holes.

Process the workpiece 6 with an aperture of 2mm and a depth of 60mm, i.e. a smooth through hole, and fix the workpiece 6 in the fixture of the workbench. _The electrolyte with a mass concentration of 15% NaNO3 flows from the bottom of the smooth through hole. And upward flow; first feed the tool electrode A into the smooth through hole on the workpiece 6 to be processed, the tool electrode A is connected to the negative pole of the power supply, the workpiece 6 to be processed is connected to the positive pole of the power supply, the applied voltage is 10V, the processing time is 10min, and the processing ends Finally, the tool electrode A is taken out; then the tool electrode B10 is fed to the same position again for secondary electrolytic machining, the applied voltage is 10V, and the processing time is 10min. The conductive parts of the tool electrode B10 are located on the left and right sides in the axial direction thereof. During the processing, the tool electrode B10 swings back and forth in the circumferential direction at an angle of 60°, and the ellipsoidal bamboo hole is obtained after the processing is completed.

Claims (3)

1. A method for electrochemically machining ellipsoidal bamboo joint holes, characterized in that: said method may further comprise the steps: 1) Preparation of tool electrode A: The surface of a smooth cylindrical metal wire or metal tube is made into annular grooves at equal intervals along the circumferential direction, and then insulating material is coated and cured in the annular grooves to form a bamboo joint with metal conductive parts and insulating parts spaced apart from each other Shaped tool electrode A; 2) Preparation of tool electrode B: The surface of a smooth cylindrical metal wire or metal tube is made into planes parallel to each other along the front and rear sides of the axial direction, and arc-shaped grooves are made at equal intervals on the left and right sides of the axial direction, and then the arc-shaped grooves and the front and rear Insulating material is coated on two parallel planes and cured to form a tool electrode B in which the front and rear sides are insulated, and the metal conductive parts on the left and right sides are spaced from the insulating part; wherein, two adjacent arcs on the tool electrode B The interval between the grooves is the same as the distance between two adjacent annular grooves on the tool electrode A, and the upper and lower widths of the annular grooves on the tool electrode A are the same as the upper and lower widths of the arc-shaped grooves on the tool electrode B , the radius of the cross-section of the metal conducting part of the tool electrode B is the same as the radius of the cross-section of the metal conducting part of the tool electrode A; 3) Processing of circular slub holes: First feed the tool electrode A into the pre-processed light hole on the workpiece to be processed, and then flow the electrolyte from bottom to top along the gap between the tool electrode A and the inner wall of the light hole on the workpiece to be processed, and then The workpiece to be processed is connected to the positive pole of the power supply, and the tool electrode A is connected to the negative pole of the power supply. An electrolytic machining zone is formed between the workpiece to be processed surrounded by the electrolyte and the metal conductive part of the tool electrode A. The surface of the workpiece to be processed is removed under the action of an electric field to form a circle. shaped bamboo hole; 4) Processing of ellipsoidal bamboo joint holes: Take out the tool electrode A in step 3), insert the tool electrode B into the circular slub hole, and the metal conductive part and the insulating part of the tool electrode B are aligned with the metal conductive part and the insulating part of the tool electrode A in the axial direction. Correspondingly, at the same time, the insulating layers on the front and rear sides of the tool electrode B are arranged front and back; the machining voltage and energization time of the electrolyte are set, and the tool electrode B is driven to reciprocate along the circumferential direction by the machine tool spindle at a set angle, and the circular bamboo joint The inner wall surface of the hole in the electrolytic processing area is subjected to secondary electrolytic processing, and the circular slub hole gradually forms an ellipsoidal slub hole. When the set electrification time is reached, the circular slub hole completely forms an ellipsoidal slub hole; Wherein, the setting angle of the reciprocating swing of the tool electrode B is 30°-60°. 2. a kind of method for electrochemically machining ellipsoidal bamboo joint hole as claimed in claim 1, is characterized in that: described step 1) in the preparation of tool electrode A; The surface of a smooth cylindrical metal wire or metal tube is coated with a layer of insulating glue at equal intervals along the circumferential direction, and cured under ultraviolet light, and then immersed in an electrolyte solution with a mass concentration of 10% NaNO ₃ Electrolytic corrosion, connect the cylindrical metal wire or metal pipe coated with insulating glue to the positive pole of the power supply, and the iron sheet in the electrolyte solution with a mass concentration of 10% NaNO ₃ to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical metal wire or a metal tube, so that the metal material on the exposed part of the cylindrical wire or metal tube surface is corroded into an annular groove shape, and then the previously coated layer of insulating glue is removed to form the metal conductive part of the tool electrode A. A photosensitive resin containing 15% SiC was uniformly coated in the corroded annular groove and cured under ultraviolet light irradiation. The photosensitive resin layer in the annular groove formed the insulating part of the tool electrode A, thereby producing the tool electrode A. 3. a kind of method for electrochemical machining ellipsoidal bamboo joint hole as claimed in claim 1, is characterized in that: in the preparation of described step 2) tool electrode B; Stretch the surface of a smooth cylindrical metal wire or metal tube along the left and right sides of the axis, coat a layer of insulating glue and cure it under ultraviolet light, and then infiltrate it into a prepared mass concentration of 10% NaNO ₃ In the electrolyte, connect the cylindrical metal wire or metal tube coated with insulating glue to the positive pole of the power supply, and connect the iron sheet in the electrolyte with a mass concentration of ₁₀ % NaNO3 to the negative pole of the power supply. After the electrolytic corrosion reaches the set time, take out the cylindrical Metal wire or metal tube, so that the metal material of the exposed part of the surface of the cylindrical metal wire or metal tube is corroded, and the front and rear sides of the axial direction form parallel planes, and 15% SiC photosensitive resin is coated on the plane, and Curing under ultraviolet light to obtain metal wires or metal tubes insulated on the front and rear sides of the axial direction; Then, coat a layer of insulating glue on the left and right sides of the axially left and right sides of the insulated metal wire or metal tube at equal intervals, and cure it under ultraviolet light. After curing, immerse it in a concentration of 10% Electrolytic corrosion is carried out in the _NaNO3 electrolyte, and the cylindrical metal wire or metal tube insulated on the front and rear sides is connected to the positive pole of the power supply. The iron sheet in the NaNO3 electrolyte with a mass concentration of ₁₀ % is connected to the negative pole of the power supply. After the electrolytic corrosion reaches the set time , take out the metal wire or metal tube, so that the metal material on the exposed part of the metal wire or metal tube surface is corroded into an arc-shaped groove, and then remove the previously coated layer of insulating glue to form the metal conductive part of the tool electrode B, Finally, a photosensitive resin containing 15% SiC is evenly coated in the corroded arc-shaped groove and cured under ultraviolet light. The photosensitive resin layer in the arc-shaped groove forms the insulating part of the tool electrode B, thereby making the tool Electrode B.