CN115837497A

CN115837497A - Method for processing V-shaped groove of ultra-long thin-walled tube

Info

Publication number: CN115837497A
Application number: CN202211517482.9A
Authority: CN
Inventors: 张亚雄; 伏金娟; 武晓会; 徐彩丽; 蔡延华; 荣田; 邢鹏
Original assignee: Beijing Electric Processing Research Institute Co ltd; Beijing Xinghang Electromechanical Equipment Co Ltd
Current assignee: Beijing Electric Processing Research Institute Co ltd; Beijing Xinghang Electromechanical Equipment Co Ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-03-24

Abstract

The invention relates to a method for processing a V-shaped groove of an ultra-long thin-walled tube, belongs to the technical field of ultra-long tube processing, and solves the problem that the V-shaped groove is difficult to be processed on the ultra-long thin-walled tube with high precision in the prior art. The method comprises the following steps: aligning the tool electrode by using a universal adjustable clamp; clamping the thin-walled tube by using the bearing assembly and aligning the thin-walled tube; the machining of the V-shaped groove on the surface to be machined is realized by utilizing the working state of a plurality of electric spark machining point positions of the tool electrode, which are circumferentially arranged around the thin-walled tube; the same electric spark machining point comprises a working state and a non-working state. The high-precision machining of the V-shaped groove of the ultra-long thin-walled tube is realized, meanwhile, the V-shaped groove can be machined in place at one time, and the machining efficiency is obviously improved.

Description

Method for processing V-shaped groove of ultra-long thin-walled tube

Technical Field

The invention relates to the technical field of processing of ultra-long pipe fittings, in particular to a processing method of a V-shaped groove of an ultra-long thin-walled pipe.

Background

V-shaped grooves need to be processed on some ultra-long and thin flying products, and the V-shaped grooves processed on the ultra-long and thin flying products have the characteristics of small diameter and thin wall thickness, so that the sizes of the V-shaped grooves are smaller. For the aviation products with the vital size control, the machining precision requirement of the V-shaped groove puts higher requirements on the machining mode of the V-shaped groove.

The machining precision requirement of the V-shaped groove is difficult to meet by adopting the traditional turning machining mode. This is because the machining accuracy of the V-groove is inevitably affected by both the clamping of the part and the application of the cutting force in the turning process.

Therefore, in order to meet the requirement of processing the V-shaped groove on the ultra-long aviation product, a new V-shaped groove processing method needs to be explored.

Disclosure of Invention

In view of the above analysis, the embodiment of the present invention aims to provide a method for machining a V-shaped groove of an ultra-long thin-walled tube, so as to solve the problem that it is difficult to machine a V-shaped groove on an ultra-long thin-walled tube with high precision.

On one hand, the embodiment of the invention provides a processing method of an ultra-long thin-walled tube V-shaped groove, which comprises the following steps:

the method comprises the following steps:

step 1: aligning the tool electrode by using a universal adjustable clamp;

step 2: clamping the thin-walled tube by using the bearing assembly and aligning the thin-walled tube;

and step 3: the machining of the V-shaped groove on the surface to be machined is realized by utilizing the working state of a plurality of electric spark machining point positions of the tool electrode, which are circumferentially arranged around the thin-walled tube;

and changing the distance between the electric spark machining point and the surface to be machined to enable the same electric spark machining point to be in a working state or a non-working state.

Based on further improvement of the method, the universal adjustable clamp comprises a clamping part for clamping the tool electrode, a first adjusting part for aligning the tool electrode on the XY surface of the machine tool, and a second adjusting part for aligning the tool electrode on the YZ surface of the machine tool;

the clamping part comprises a reference seat, a clamping seat arranged on the reference seat and a fastening screw for adjusting the clamping force of the tool electrode;

the first adjusting part comprises a first fixed seat and a second fixed seat which are distributed up and down, the second fixed seat is arranged at the lower end of the first fixed seat through a plurality of vertical screws, and the clamping part is arranged at the lower end of the second fixed seat;

the second adjusting part comprises a clamp head arranged on the machine tool, a first connecting body fixedly connected with the clamp head, a rotating body rotatably connected with the first connecting body in the horizontal direction, and a second connecting body fixedly connected with the rotating body; the second connecting body is connected with the first fixed seat;

one end of the rotating body is provided with a corner adjusting bolt, and one end of the corner adjusting bolt is screwed on the rotating body; and an angle value scale surface is arranged on the end surface of the first connecting body.

Based on a further improvement of the above method, the step 1 comprises:

s11: clamping the tool electrode by using a clamping part of the universal adjustable clamp, and pressing the tool electrode tightly by using a fastening screw;

s12: in the XY plane direction of the machine tool, the upper and lower spatial positions of the vertical screw are adjusted to adjust the inclination angle of the second fixed seat in the horizontal direction;

s13: the position of the rotating body on the horizontal plane is adjusted in the direction of the YZ plane of the machine tool, so that the inclination angle of the tool electrode on the YZ plane of the machine tool is adjusted.

Based on a further improvement of the above method, the step S13 includes:

s131: in the YZ plane direction of the machine tool, taking the discharge end surface of the tool electrode as a reference surface, and moving the tool electrode on the reference surface along the Y axis direction of the machine tool by using a dial indicator to align the tool electrode;

s132: and pushing the corner adjusting bolt to drive the rotating body to rotate through the corner adjusting bolt so as to adjust the inclination angle of the tool electrode on the YZ plane of the machine tool.

Based on the further improvement of the method, in step S132, the surface provided with the scales on the end surface of the first connecting body is used as a reference surface, the corner adjusting bolt is pushed, and the pushing angle is β;

wherein, use the center of rotor as the centre of a circle, angle beta that corner adjusting bolt promoted satisfies:

s is the movement distance of a pointer of a dial gauge when the inclination angle of the tool electrode is detected in the direction of a YZ surface of the machine tool; v. of ₁ The speed of movement of the dial indicator; t is t ₁ The time of dial indicator movement.

Based on the further improvement of the method, the central line of the discharge end of the tool electrode is parallel to the upper end surface and the lower end surface of the second fixed seat, and the tool electrode moves synchronously when the second fixed seat is adjusted.

Based on the further improvement of the method, one end of the tool electrode is a discharge end, the discharge end comprises a plurality of electric spark machining points circumferentially arranged around the thin-walled tube, during machining, the plurality of electric spark machining points circumferentially arranged around the thin-walled tube form a continuous circular ring, and the inner circular end of the circular ring is matched with the V-shaped groove in shape;

the discharging end of the tool electrode is sleeved on the thin-walled tube, and during machining, the discharging end of the tool electrode moves eccentrically around the central axis of the inner cavity of the thin-walled tube.

Based on the further improvement of the method, when the discharge end of the tool electrode performs eccentric motion around the central axis of the inner cavity of the thin-walled tube for machining, the single-side feed O ₁ O ₂ Satisfies the following conditions:

O ₁ O ₂ ＝S ₁ +(H ₁ -H ₂ )-S ₂

wherein H ₁ The wall thickness of the thin-walled tube; h ₂ The wall thickness of the V-shaped groove; s ₁ The distance between the discharge end of the tool electrode and the surface to be processed is the distance before processing; s ₂ To machine the gap.

Based on the further improvement of the method, the driving component is utilized to drive the discharging end of the tool electrode to perform eccentric motion around the central axis of the inner cavity of the thin-walled tube;

wherein the non-electrical parameters satisfy:

the swing speed of the driving component is 0.4-0.6 rpm, the processing clearance is 10-50 μm, and the processing speed is 0.02-0.045 g/min.

Wherein the electrical parameter satisfies:

the pulse width is 30-60 mus, the pulse interval is 20-30 mus, the average processing current is 0.8-2A, and the average processing voltage is 30-60V.

Based on the further improvement of the method, the step 2 comprises the following steps:

s21: fixing the bearing assembly on a workbench of a machine tool, and aligning the bearing assembly by using the machine tool;

s22: penetrating the thin-walled tube through the discharge end of the tool electrode, and clamping the thin-walled tube by using the bearing assembly;

s23: and adjusting the bearing assembly through a machine tool to drive the thin-wall tube to move until the central axis of the inner cavity of the thin-wall tube is superposed with the central line of the discharge end of the tool electrode.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

1. the inclination angle of the tool electrode on the horizontal plane is adjusted through the first adjusting part of the universal adjustable clamp; according to the detection value of the dial indicator and the moving time and speed of the dial indicator, the inclination angle of the tool electrode on the YZ surface of the machine tool is determined, the angle scale value on the first connecting body is compared, the rotation angle adjusting bolt is pushed to the corresponding scale, the inclination angle of the tool electrode on the YZ surface of the machine tool can be adjusted in a high-precision mode, the tool electrode is aligned, operation is convenient, and machining efficiency and precision are improved.

2. During machining, the ultra-long thin-walled tube is placed in the V-shaped grooves in the equal-height positioning blocks and the auxiliary bearing blocks, the clamping plate is used for limiting the upper surface of the ultra-long thin-walled tube, the ultra-long thin-walled tube can be clamped and positioned, the clamping is convenient and fast, and the stability of the ultra-long thin-walled tube in the machining process can be ensured.

3. The tool electrode has a circular discharge end which is sleeved on the outer end face of the ultra-thin-walled tube to perform eccentric motion, the distance between the end face of the discharge end and the end face to be machined of the ultra-thin and long thin-walled tube is continuously changed in the process, the end face which is closer is a working end, and the end face which is farther is a non-working end, so that the outer end face of the ultra-thin and long thin-walled tube is subjected to electric spark machining through the working end; the position of the working end is continuously changed on the inner circle end face of the discharge end along the machining direction, namely when the inner circle end face of the discharge end is close to the outer end face of the ultra-long thin-walled tube, the end face of the discharge end is a working end, when the end face is far away from the outer end face of the ultra-long thin-walled tube, the end face is changed into a non-working end, and dynamic change between the working end and the non-working end is realized, so that the working end of the tool electrode is prevented from being in a continuous machining state, loss of the working end of the tool electrode is greatly reduced, loss of the tool electrode is not more than 1%, and further, deformation of the working end face of the tool electrode is reduced, and machining precision of a V-shaped groove of the ultra-long thin-walled tube is improved.

4. The discharge end of the tool electrode is sleeved on the ultra-thin-walled tube to do eccentric motion, when in machining, the distance between the discharge end and the ultra-thin-walled tube is reduced from large to small and then increased from small to large, metal debris can be generated between the discharge end and the thin-walled tube in the process of reducing the distance from large to small, at the moment, part of the metal debris can be discharged along with working fluid through a machining gap, in the process of reducing the distance to large, the distance between the discharge end and the thin-walled tube can be increased by nearly 200 times, the efficiency of discharging the metal debris is remarkably improved, the metal debris is prevented from being accumulated at the discharge end due to untimely discharge, the loss of the tool electrode is reduced, and the risk of short circuit caused by the fact that the tool electrode is directly connected with the thin-walled tube through the metal debris is avoided.

5. The discharge end sleeve of the tool electrode can perform eccentric motion on the ultra-thin-walled tube, so that metal scraps can be efficiently discharged, and further, the electric spark machining can be performed with a small machining gap, so that the machining current and the machining voltage can be reduced, the machining cost is reduced, and the V-shaped groove with low surface roughness can be obtained.

6. The V-shaped grooves with different wall thicknesses can be machined by adjusting the value of the single-side feeding amount, the machining of the sizes of different oblique angles alpha can be realized by adjusting the shape of the discharge end of the tool electrode, and a foundation is laid for the rapid production and batch production of products.

7. The tool electrode eccentrically moves for a circle around the central axis of the inner cavity of the ultra-long and thin stainless steel pipe, so that the processing of the broken groove of the ultra-long and thin stainless steel pipe can be finished, the one-time processing in place is realized, and the processing efficiency is obviously improved.

8. The invention abandons the traditional turning mode for the ultra-long stainless steel pipe, utilizes the working end of the tool electrode to discharge and corrode and remove the metal on the surface of the ultra-long stainless steel pipe, and carries out the fracture groove machining, namely, in the machining process, the tool electrode is not contacted with the surface of the ultra-long stainless steel pipe, thereby not causing the deformation of the ultra-long stainless steel pipe and overcoming the damage problem of the cutting force to the ultra-long stainless steel pipe.

9. The invention utilizes the eccentric motion of the discharge end of the tool electrode around the central axis of the inner cavity of the ultra-long stainless steel pipe to process the breaking groove of the ultra-long stainless steel pipe, namely, the ultra-long stainless steel can realize the processing of the annular breaking groove on the outer surface without rotating in the processing process, thereby overcoming the problem that the coaxiality of the ultra-long stainless steel pipe is deteriorated in the rotation process to influence the processing precision.

10. The discharging end of the tool electrode eccentrically moves around the central axis of the inner cavity of the stainless steel pipe, so that the single-side feeding amount of the end face of each discharging end is the same, the consistency of the processing depth of the breaking groove is ensured, and the processing precision of the breaking groove is improved.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a flow chart of the processing method of the V-shaped groove of the ultra-long thin-walled tube of the invention;

FIG. 2 is a schematic view of a tool electrode structure according to the present invention;

FIG. 3 is a schematic view of the overall structure of the universally adjustable clamp of the present invention;

FIG. 4 is a schematic cross-sectional view of a universally adjustable clamp of the present invention;

FIG. 5 is a schematic view of a mating structure of the adjusting screw and the first connecting body according to the present invention;

FIG. 6 isbase:Sub>A schematic cross-sectional view taken at A-A in FIG. 2;

FIG. 7 is a schematic structural diagram of the tool electrode of the present invention with the center line of the discharge end coinciding with the central axis of the inner cavity of the stainless steel tube;

FIG. 8 is a schematic view of the tool electrode of the present invention when the center line of the tool electrode is deviated from the central axis of the inner cavity of the stainless steel tube;

FIG. 9 is a schematic cross-sectional view of the discharge end of the tool electrode of the present invention fitted over a stainless steel tube;

FIG. 10 is a view showing the center O of the discharge end of the tool electrode of the present invention moving eccentrically around the central axis of the inner cavity of the stainless steel tube ₂ Schematic diagram of motion trail of;

FIG. 11 shows that when the discharge end of the tool electrode of the present invention eccentrically moves around the central axis of the inner cavity of the stainless steel tube, any point O on the discharge end ₃ Schematic diagram of motion trail of;

FIG. 12 is a schematic view of the structure of the stainless steel pipe rupture groove of the present invention;

FIG. 13 is a schematic view of the structure of the load bearing assembly of the present invention engaged with a stainless steel tube;

FIG. 14 is a schematic view of the structure of the positioning blocks, clamping plates and stainless steel tubes of the present invention;

FIG. 15 is a schematic view of the structure of the auxiliary bearing block and the stainless steel tube;

FIG. 16 is a schematic view showing a processed stainless steel pipe fracture groove according to the present invention.

Reference numerals:

1-a tool electrode; 101-a discharge end; 102-a working end; 103-non-working end; 104-a conductive terminal; 2-a transmission rod; 3-equal-height positioning blocks; 4-an auxiliary bearing block; 5-clamping the plate; 6-stainless steel tube; 601-breaking the groove; 7-machine direction; 8-direction of eccentric motion; 9-a machine tool workbench; 10-a reference seat; 11-a holder; 12-a fastening screw; 13-a first fixed seat; 14-a second fixed seat; 15-vertical screws; 16-an insulating plate; 17-a gripper head; 18-a first connector; 19-a second linker; 20-a rotor; 21-corner adjusting bolts; 22-notches; 23-the moving direction of the dial indicator on the discharge end surface of the tool electrode along the Z-axis direction of the machine tool; 24-the moving direction of the dial indicator on the discharge end surface of the tool electrode along the Y-axis direction of the machine tool; h ₁ -wall thickness of stainless steel tube; h ₂ -breaking groove wall thickness; alpha-breaking groove bevel angle; s. the ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ -actual residual gap values between four points selected on the circular working end of the tool electrode to the outer end face of the stainless steel tube; s ₂ -machining the gap; o is ₁ -a discharge end center point; o is ₂ -stainless steel tube lumen center point; o is ₃ -a selected point on the discharge end.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

The ratio of the diameter to the length is 1. For example, the stainless steel tube used on a certain aviation product has the outer diameter of 2mm, the inner diameter of 1mm and the length of 1-1.2 m, and the ratio of the outer diameter to the length of the stainless steel tube is 1-600, and the stainless steel tube belongs to an ultra-long stainless steel tube. When the device is used, a V-shaped groove is generally required to be processed on the ultra-long steel pipe, and the V-shaped groove is a fracture groove and used for separating the flying product guidance system from the product fairing body when a product reaches a preset height and position.

Because the superfine stainless steel pipe has small diameter and thin wall thickness, and the wall thickness of the breaking groove is thinner, if the wall thickness of the breaking groove is 0.3 +/-0.05 mm, the important size of the superfine stainless steel pipe cannot be obtained through direct measurement; when the breaking groove is machined at a certain position of the ultra-thin and long stainless steel pipe, the wall thickness of the breaking groove is difficult to ensure by adopting a traditional turning machining mode, because the centrifugal force of the workpiece rotating caused by the overlong length in the rotating process is larger, the coaxiality of the workpiece is worse, and the generated cutting force easily causes the deformation of the ultra-thin and long stainless steel pipe.

In order to solve the problems, the invention provides a method for processing a V-shaped groove of an ultra-long thin-walled tube, which comprises the following steps:

step 1: aligning the tool electrode by using a universal adjustable clamp;

Specifically, one end of the tool electrode 1 is a discharge end 101, and the discharge end 101 comprises a plurality of electric spark machining points circumferentially arranged around the thin-walled tube;

when the distance between the electric spark machining point and the surface to be machined is larger than a threshold value, the electric spark machining point is in a non-working state;

when the distance between the electric spark machining point and the surface to be machined is smaller than or equal to a threshold value, the electric spark machining point is in a working state;

the threshold value is the discharge distance between the electric spark machining point position meeting the machining requirement and the surface to be machined.

It can be understood that the discharge end 101 includes a plurality of electrical discharge machining points circumferentially arranged around the thin-walled tube, and the plurality of electrical discharge machining points circumferentially arranged around the thin-walled tube may be continuously and circumferentially distributed around the thin-walled tube, or may be discontinuously distributed around the thin-walled tube, so that continuous machining and forming of the V-shaped groove on the surface to be machined can be achieved.

In a possible embodiment, one end of the tool electrode 1 is annular, that is, a plurality of electrical discharge machining points arranged around the circumference of the thin-walled tube form a continuous annular shape, as shown in fig. 6 to 9, the inner circle end of the annular ring is matched with the shape of the V-shaped groove, that is, the inner circle end is convex, the V-shaped groove is concave, and the cross-sectional size of the convex shape is the same as the cross-sectional shape of the concave shape; the other end of the tool electrode 1 is a conductive end 104, and is electrically connected with an output end of a power supply device arranged on the machine tool, so as to introduce current and transmit the current to an inner circle end, at this time, the inner circle end is a discharge end 101, and the machining of the V-shaped groove on the surface to be machined is realized through the working state of a plurality of electric spark machining points of the discharge end 101, which are circumferentially arranged around the thin-walled tube.

In a possible embodiment, the discharge end is a rigid structure, and the discharge end 101 is sleeved on the outer end surface of the stainless steel tube 6; when in processing, the stainless steel tube 6 is electrically connected with the other output end of the power supply device, and the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6; wherein, in the process of the eccentric motion of the tool electrode 1, the distance between the inner circle end surface of the discharge end 101 and the end surface to be processed of the stainless steel tube 6 is constantly changed; when the distance between the electric spark machining point and the surface to be machined is larger than the threshold value, the electric spark machining point is in a non-working state, and at the moment, the electric spark machining point is a non-working end 103; when the distance between the electric spark machining point and the surface to be machined is smaller than or equal to the threshold value, the electric spark machining point is in a working state, and at the moment, the electric spark machining point is a working end 102, so that the working state and the non-working state are changed at the same electric spark machining point, the working states of all the electric spark machining points jointly realize machining of the broken groove on the surface to be machined, namely, the position of the working end 102 is continuously changed in the inner circular end surface of the discharge end 101, the circular discharge end of the tool electrode eccentrically moves for a circle around the central axis of the inner cavity of the stainless steel pipe, and all the working ends form continuous circular discharge ends around the stainless steel pipe in the circumferential direction, so that the discharge end 101 of the tool electrode 1 is prevented from being in a continuous machining state, and further the loss of the tool electrode 1 is reduced.

The annular discharge end 101 of the tool electrode 1 comprises a plurality of working ends 102 which are distributed annularly, and when the discharge end eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6 to be machined, the working ends 102 are in an asynchronous and non-continuous machining state; and the processing tracks of the plurality of working ends jointly form a breaking groove of the stainless steel pipe 6.

After the tool electrode 1 eccentrically moves for a circle, all end faces of the discharge end 101 participate in electric spark machining, namely, all working ends 102 form the complete discharge end 101, and machining tracks of all working ends 102 form the ultra-long stainless steel pipe breaking groove 601 together; along the machining direction 7, the working ends 102 have a circular motion phenomenon on the discharge end 101, that is, the positions of the working ends 102 are different at different times, so that all the working ends 102 are machined alternately and orderly, the machining direction 7 is the circumferential direction around the outer end surface of the stainless steel tube 6, and the surface where the circumferential direction is located is perpendicular to the central axis of the inner cavity of the stainless steel tube 6.

Compared with the prior art, the tool electrode can be conveniently aligned by using the universal adjustable clamp, the thin-wall tube can be aligned by using the bearing assembly, so that the central axis of the inner cavity of the thin-wall tube is superposed with the central line of the discharge end of the tool electrode, the value of single-side feeding amount can be conveniently determined, meanwhile, the discharge end of the tool electrode eccentrically moves around the central axis of the inner cavity of the thin-wall tube, the equal single-side feeding amount values of a plurality of electric spark machining point positions are realized, and the machining precision of the V-shaped groove is further improved. And the discharge end 101 of the tool electrode 1 is in a circular ring shape and is sleeved on the outer end face of the stainless steel tube 6 to perform eccentric motion, in the process, the distance between the end face of the discharge end 101 and the end face to be machined of the stainless steel tube 6 is continuously changed, the end face which is closer is the working end 102, the end face which is farther is the non-working end 103, the outer end face of the stainless steel tube 6 is subjected to electric spark machining through the working end 102, and along the machining direction, the position of the working end 102 is continuously changed in the inner circle end face of the discharge end 101, namely, when the inner circle end face of the discharge end 101 is close to the outer end face of the stainless steel tube 6, the end face of the discharge end 101 is the working end 102, and when the end face is far away from the outer end face of the stainless steel tube 6, the end face is changed into the non-working end 103, so that dynamic change between the working end 102 and the non-working end 103 is realized, thereby avoiding that the working end 102 of the tool electrode 1 is in a continuous machining state, greatly reducing the loss of the working end of the tool electrode 1, realizing that the loss of the tool electrode is less than or equal to 1, further reducing the working end face deformation of the tool electrode, and improving the precision of the broken groove 601 of the stainless steel tube 601 for machining of the ultra-long stainless steel tube.

The criterion for determining whether the discharge end 101 is the working end 102 is whether the distance between the discharge end 101 and the surface to be processed of the stainless steel tube 6 is greater than 50 μm, if not, the discharge end 101 is the working end 102, and if so, the discharge end 101 is the non-working end 103.

Wherein, the surface on which the moving tracks in the X-axis direction and the Y-axis direction of the machine tool are located is an XY surface, namely a horizontal plane; the plane on which the moving track of the machine tool moves in the Y-axis direction and the Z-axis direction is the YZ plane.

Specifically, the step 1 includes the steps of:

s11: clamping the tool electrode 1 by using a clamping part of the universal adjustable clamp, and pressing the tool electrode 1 by using a fastening screw 12;

s12: in the XY plane direction of the machine tool, the upper and lower spatial positions of the vertical screw 15 are adjusted to adjust the inclination angle of the second fixed seat 14 in the horizontal direction;

s13: the position of the rotating body 20 in the horizontal plane is adjusted in the machine tool YZ plane direction, thereby adjusting the tilt angle of the tool electrode 1 in the machine tool YZ plane.

In S11, the clamping portion of the universal adjustable fixture includes a reference seat 10 and a clamping seat 11 installed on the reference seat 10, where as shown in fig. 3-4, a clamping space for installing the tool electrode 1 is formed between adjacent surfaces of the clamping seat 11 and the reference seat 10, and when the universal adjustable fixture is installed, the upper end of the tool electrode 1 is installed in the clamping space, so as to clamp the tool electrode 1. The clamping part further comprises a fastening screw 12 for adjusting the clamping force of the tool electrode 1, the fastening screw 12 is screwed on the clamping seat 11, and one end of the fastening screw penetrates through the clamping seat 11 and is located in the clamping space. When the tool electrode 1 is installed, after the upper end of the tool electrode 1 is placed in the clamping space, the fastening screw 12 is rotated, and the end face of the tool electrode 1 is pressed by the fastening screw 12 to press the tool electrode 1 tightly to prevent the tool electrode 1 from sliding.

Further, the inner end face of the clamping space connected with the tool electrode 1 is a V-shaped face, the upper end face of the tool electrode 1 is matched with the V-shaped face, and the angle of the V-shaped face is 90 degrees, so that the tool electrode 1 is prevented from sliding in the horizontal direction in the process of pressing the tool electrode 1 by the fastening screw 12. Thus, the clamping of the tool electrode 1 is realized.

Specifically, in S12, the tilt angle of the tool electrode 1 on the XY plane is adjusted by the first adjustment portion of the universally adjustable jig. The first adjusting part comprises a first fixed seat 13 and a second fixed seat 14 which are distributed up and down, the second fixed seat 14 is installed at the lower end of the first fixed seat 13 through a vertical screw 15, and a gap is formed between adjacent surfaces of the first fixed seat 13 and the second fixed seat 14; wherein, the one end of vertical screw 15 passes through first fixing base 13 and second fixing base 14 to with first fixing base 13 spiro union, and with second fixing base 14 sliding connection, be equipped with the nut in the bottom of vertical screw 15, with in the direction of perpendicular to second fixing base 14, carry out spacing so as to adjust the inclination of second fixing base 14 in the XY direction through rotatory vertical screw 15 to second fixing base 14.

Wherein, be equipped with four perpendicular screws 15, and vertical, even distribution is on first fixing base 13, and the top of four perpendicular screws 15 is the rotating head, is convenient for from here application of force in order to rotate perpendicular screw 15, and under the initial condition, be equipped with the same surplus clearance between the rotating head of all perpendicular screws 15 and the up end of first fixing base 13 to ensure that perpendicular screw 15 has sufficient precession space.

Further, an insulating plate 16 is fixedly mounted at the lower end of the second fixing seat 14, and the reference seat 10 is fixedly connected with the lower end face of the insulating plate 16, so that when the inclination angle of the second fixing seat 14 in the horizontal direction is adjusted, the tool electrode 1 can be aligned in the vertical direction, and meanwhile, the insulating plate 16 can prevent an operator from getting an electric shock.

Exemplarily, the vertical screw 15 located at the left end of the first fixing base 13 is rotated clockwise, and then the vertical screw 15 drives the left end of the second fixing base 14 to incline downwards, at this time, the second fixing base 14 drives the reference base 10 to move synchronously through the insulating plate 16, and then drives the lower end of the tool electrode 1 to incline rightwards. Therefore, by rotating any one vertical screw 15, the second fixing seat 14 can be locally adjusted to move up and down in the Z axis and direction, the inclination angle of the second fixing seat 14 in the XY direction can be adjusted, and the inclination angle of the tool electrode in the XY direction can be adjusted.

Specifically, in S13, the tilt angle of the tool electrode 1 in the YZ direction of the machine tool is adjusted by the second adjusting portion of the universally adjustable jig. As shown in fig. 3 to 5, the second adjusting portion includes a clamp head 17, a first connecting body 18, a second connecting body 19 and a rotating body 20, wherein the clamp head 17 is mounted on the machine tool, the first connecting body 18 is fixedly connected to the clamp head 17, the rotating body 20 is located between the first connecting body 18 and the second connecting body 19, an upper end of the rotating body 20 is rotatably connected to the first connecting body 18 in a horizontal direction, a lower end of the rotating body 20 is fixedly connected to the second connecting body 19, and a lower end of the second connecting body 19 is fixedly connected to a top of the first fixing base 13, so that the rotating body 20 rotates in the horizontal direction to control the second connecting body 19 to rotate in the horizontal plane, thereby adjusting a position of the first fixing base 13 in the horizontal direction, and further aligning the tool electrode 1 in a YZ direction of the machine tool.

The lower end of the first connecting body 18 is provided with a cavity for placing the rotating body 20, the rotating body 20 is placed in the cavity, and the upper end of the rotating body 20 is rotatably installed on the top wall of the cavity; one end of the rotating body 20 is provided with a corner adjusting bolt 21, one end of the corner adjusting bolt 21 is screwed on the rotating body 20, and the other end of the corner adjusting bolt 21 penetrates through the cavity wall of the first connecting body 18 and is positioned outside the first connecting body 18; a notch 22 is formed on the side end face of the first connecting body 18, so that when the rotating body 20 rotates, the rotation angle adjusting bolt 21 can slide in the notch 22; the end part of the corner adjusting bolt 21, which is located outside the first connecting body 18, is a bolt head, and by rotating the bolt head, the corner adjusting bolt 21 can be close to or far away from the first connecting body in the direction towards the first connecting body, so that the pressing force of the corner adjusting bolt 21 on the first connecting body 18 can be adjusted, and the state of the rotating body 20 can be adjusted.

Illustratively, the rotation angle adjusting bolt 21 is rotated counterclockwise until the pressing force of the rotation angle adjusting bolt 21 on the first connecting body 18 is removed, at which time the rotating body 20 can rotate freely, and the rotation angle is limited by the length of the notch 22.

Illustratively, the rotation angle adjusting bolt 21 is rotated clockwise until the rotation angle adjusting bolt 21 presses against the end face of the first connecting body 18, at which time the rotor 20 cannot rotate.

Furthermore, the length direction of the notch 22 is provided with a scale of a rotation angle, wherein the rotation angle adjusting bolt 21 is positioned at the middle part of the notch 22 and is 0 degree, and when the rotation angle adjusting bolt 21 rotates clockwise, the maximum position of the rotation angle adjusting bolt 21 moving is 10-30 degrees; when the tool electrode 1 rotates anticlockwise, the maximum position of the rotation angle adjusting bolt 21 is-30 degrees to-10 degrees, so that the rotation angle of the rotating body 20 can be accurately adjusted, and the tool electrode 1 can be accurately adjusted.

Wherein, the surface of the first connecting body 18 with the scale on the end surface is used as a reference surface to push the corner adjusting bolt 21 to rotate, and the pushing angle is beta;

wherein, with the center of the rotating body 20 as the center of circle, the angle β that the corner adjusting bolt 21 promotes satisfies:

wherein, S: taking the discharge end face of the tool electrode 1 as a reference surface, moving a dial indicator in the Y-axis direction of the machine tool, wherein the movement distance of a pointer of the dial indicator is S;

v ₁ the speed of movement of the dial indicator;

t ₁ the time of dial indicator movement.

In the process of aligning the tool electrode 1, a dial indicator is used for aligning the tool electrode 1 to set a reference surface to adjust the universal adjustable fixture, so that the relative position error of the tool electrode and the XYZ axis of the machine tool is less than or equal to 0.01mm.

Specifically, in step 2, the bearing assembly comprises an equal-height positioning block 3 and an auxiliary bearing block 4 which are arranged on the machine tool; so as to place the stainless steel tube 6 on the equal-height positioning block 3 and the auxiliary bearing block 4 to clamp the stainless steel tube 6.

Specifically, as shown in fig. 12 to 15, two equal-height positioning blocks 3 are provided, and the two equal-height positioning blocks 3 are respectively located at two sides of the position to be processed of the stainless steel tube 6, so as to ensure the stability of the position to be processed of the stainless steel tube 6 during the processing process. Illustratively, the distance between two equal-height positioning blocks 3 is 20-50mm.

Specifically, two auxiliary bearing blocks 4 are arranged, and two equal-height positioning blocks 3 are located between the two auxiliary bearing blocks 4, so that the two ends of the stainless steel pipe 6 are supported and positioned through the two auxiliary bearing blocks 4, and the stability of the stainless steel pipe 6 in the machining process is further ensured.

The upper end faces of the equal-height positioning block 3 and the auxiliary bearing block 4 are flush, a V-shaped groove is formed in the upper end faces of the equal-height positioning block 3 and the auxiliary bearing block 4, and the stainless steel pipe 6 is placed in the V-shaped groove to limit the stainless steel pipe 6.

Furthermore, the equal-height positioning blocks 3 are also provided with clamping plates 5, the clamping plates 5 cover the V-shaped grooves and are clamped on the equal-height positioning blocks 3 to limit the stainless steel pipes 6, and the stability of the stainless steel pipes 6 is further improved. Illustratively, the V-shaped groove has an angle of 60 to 90 degrees and a depth of 5 to 10mm.

Before the stainless steel tube 6 is placed on the equal-height positioning block 3, firstly, a machine tool is used for centering and aligning the tool electrode 1, then the stainless steel tube 6 is inserted into the discharge end 101 of the tool electrode 1, finally, the equal-height positioning block 3, the auxiliary bearing block 4 and the clamping plate 5 are used for clamping the stainless steel tube 6, and the equal-height positioning block 3 and the auxiliary bearing block 4 are used for centering the stainless steel tube 6.

Specifically, after the tool electrode 1 is aligned, the XYZ axes of the machine tool are utilized to adjust the positions of the equal-height positioning block 3 and the auxiliary bearing block 4 on the machine tool so as to align the stainless steel tube 6, ensure that the central axis of the inner cavity of the stainless steel tube 6 coincides with the central line of the discharge end 101 of the tool electrode 1, so as to determine the value of the unilateral feeding amount and further improve the machining precision.

The alignment process of the stainless steel pipe 6 is as follows.

Firstly, fixing 2 equal-height positioning blocks 3 and 2 auxiliary supporting blocks 4 on a workbench 9 of a machine tool, and then utilizing a dial indicator to align the side surface of the dial indicator to be parallel to the X axis of the machine tool, wherein the parallelism error is less than or equal to 0.01mm.

Before the stainless steel tube 6 is placed on the equal-height positioning block 3, the stainless steel tube 6 is firstly inserted into the discharge end 101 of the tool electrode 1, and then the stainless steel tube 6 is placed on the equal-height positioning block 3 and the auxiliary bearing block 4, so that the stainless steel tube 6 is aligned through the equal-height positioning block 3 and the auxiliary bearing block 4.

Specifically, in step 3, the tool electrode 1 is clamped in the clamping part, and the reference seat 10 of the clamping part is connected with a driving assembly, wherein the driving assembly comprises a transmission rod 2, namely, one end of the transmission rod 2 is connected with the reference seat 10 and is parallel to the central line of the discharge end 101 of the tool electrode 1; in the machining process, the other end of the transmission rod 2 is installed on a machine tool to move through the machine tool to drive the transmission rod 2 to swing, and then the tool electrode 1 and the universal adjustable fixture are driven to move through the transmission rod 2, so that the discharge end 101 of the tool electrode 1 does eccentric motion around the central axis of the inner cavity of the stainless steel tube 6, therefore, the discharge end 101 of the tool electrode surrounds the end face of the stainless steel tube 6 to perform electric spark machining, the machining direction 7 is the circumferential direction around the outer end face of the stainless steel tube 6, and the central line of the circumferential direction is overlapped with the central axis of the inner cavity of the stainless steel tube 6.

Specifically, before the tool electrode 1 performs eccentric motion, the center of the inner circular end of the discharge end 101 of the tool electrode 1 needs to be adjusted to coincide with the central axis of the stainless steel tube 6, and a margin gap is formed between the discharge end 101 and the outer end surface of the stainless steel tube 6, that is, the discharge end101 have a diameter dimension greater than the outer diameter dimension of the stainless steel tube 6, illustratively 10 to 20mm, which is 5 to 10 times the outer diameter of the stainless steel tube 6. Thereby, during the electric discharge machining, the determination of the single-side feed amount O is facilitated ₁ O ₂ The value of (c).

Wherein the single-side feed amount O ₁ O ₂ Satisfies the following conditions:

O ₁ O ₂ ＝S ₁ +(H ₁ -H ₂ )-S ₂

wherein, O ₁ Represents the center point of the discharge end 101 of the tool electrode 1;

O ₂ the center point of the inner cavity of the stainless steel pipe 6 is shown;

H ₁ the wall thickness of the stainless steel tube 6;

H ₂ the wall thickness of the breaking groove 601;

S ₁ a margin gap is formed between the discharge end 101 and the outer end face of the stainless steel tube 6;

S ₂ the machining clearance is the closest distance between the working end 102 and the end face of the stainless steel pipe 601 when the tool electrode 1 moves eccentrically.

Wherein S is ₁ Satisfies the following conditions:

wherein, as shown in FIG. 7, S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ Four points are evenly distributed on the discharge end 101 for the actual margin gap value between the selected four points on the discharge end 101 of the tool electrode 1 and the outer end surface of the stainless steel pipe 6.

Exemplary, S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ Respectively 2.055mm, 2.060mm, 2.065mm, 2.050mm, in which case S ₁ ＝2.058mm。

Wherein the machining gap S ₂ The value is 10-50 μm to meet the requirement of electric spark machining.

Exemplary, S ₂ ＝10μm；H ₁ ＝0.5mm，H ₂ ＝0.3mm，S ₁ =2.058mm, in which case O ₁ O ₂ ＝2.248mm。

Wherein the measurement S can be performed by means of an automatic centering module on the machine tool ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ If the four values are equal, the center of the inner circular end of the discharge end 101 of the tool electrode 1 coincides with the central axis of the inner cavity of the stainless steel tube 6.

Wherein, after the center of the discharge end 101 of the tool electrode 1 is adjusted by the machine tool to coincide with the central axis of the inner cavity of the stainless steel tube 6, the actually measured S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ The closer the four values of (1) are, the more precise the value of S1 and thus the one-sided feed O ₁ O ₂ The more accurate, the more accurate the machining gap during the eccentric motion of the tool electrode 1 can be ensured, and the machining depth of the working end 102 can be ensured, so as to ensure the dimensional accuracy of the machined breaking groove 601.

Specifically, after the center of the discharge end 101 of the tool electrode 1 is adjusted to coincide with the central axis of the inner cavity of the stainless steel tube 6, the tool electrode 1 is driven by a machine tool to perform eccentric motion, and the detailed process is shown below.

At the center point O of the discharge end 101 of the tool electrode 1 ₁ And the center point O of the inner cavity of the stainless steel pipe 6 ₂ The motion trajectory of (2) is illustrated as follows:

moving the tool electrode 1 so that O ₁ Away from O ₂ Distance of travel and one-side feed O ₁ O ₂ Same, at this time, O ₁ And O ₂ Has a distance of O ₁ O ₂ ；

With O ₂ Centered on O ₁ O ₂ To a radius, adding O ₁ Around O ₂ Rotation at this time, O ₁ The moving track is a circle, as shown in FIG. 10, the center of which is O ₂ Radius of O ₁ O ₂ ；

Wherein in the movement of O ₁ When the shortest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10 μm, the power supply is turned on to supply pulses to the tool electrode 1 and the stainless steel tube 6Punching voltage and etching the metal on the surface of the stainless steel pipe 6 at a processing speed of 0.04g/min until O ₁ And O ₂ Has a distance of O ₁ O2, then O ₁ Around O ₂ Performing a circular motion.

To further illustrate the motion trajectory of the tool electrode 1, an arbitrary point O on the discharge end 101 is selected ₃ With O ₃ Is illustrated as follows:

moving the tool electrode 1 so that O ₃ Towards O ₂ Moving by a distance O ₁ O ₂ ；

At O ₁ Around O ₂ At the time of rotation, O is shown in FIG. 11 ₃ The trajectory of (a) is: with O ₃ Is taken as the center of a circle and takes O as the center ₁ O ₂ A circle with a radius;

wherein, in O ₃ In the moving process, when the nearest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10 micrometers, a power supply device is started to transmit pulse voltage to the tool electrode 1 and the stainless steel tube 6, and metal on the surface of the stainless steel tube 6 is etched at the machining speed of 0.04g/min until O is reached ₃ Is moved by a distance of O ₁ O ₂ Then, O ₃ Then, the initial position is used as the center of a circle to do circular motion.

Therefore, in the process of the eccentric motion of the tool electrode 1, the distance between the inner circular end surface of the discharge end 101 and the outer surface of the stainless steel tube 6 is continuously changed, the distance between each part of the inner circular end surface of the discharge end 101 and the outer end surface of the stainless steel tube 6 is changed from close to far, and further, the discharge end 101 is changed from the working state to the non-working state, namely, the dynamic change between the working end 102 and the non-working end 103 is realized.

An allowance gap is formed between the discharge end 101 and the outer end face of the stainless steel tube 601, so that a non-machining gap between the non-working end 103 of the discharge end 101 and the end face of the stainless steel tube 6 is large enough, and the pulse voltage released from the non-working end 103 cannot erode metal on the surface of the stainless steel tube 6. Thus, dynamic switching between the working end 102 and the non-working end 103 is achieved when the tool electrode 1 is moved eccentrically.

The conductive end 104 of the tool electrode 1 is electrically connected with one output end of a power supply device arranged on the machine tool, the stainless steel tube 6 is electrically connected with the other output end of the power supply device, wherein the power supply device comprises a pulse power supply, and the two output ends of the pulse power supply are respectively connected with the positive electrode and the negative electrode of the pulse power supply and used for outputting pulse voltage.

During processing, the stainless steel tube 6 and the discharge end 101 of the tool electrode 1 are immersed in a liquid medium with a certain degree of insulation, such as kerosene, mineral oil or deionized water; when pulse voltage is applied to the discharge end 101 and the stainless steel tube 6, the liquid medium at the closest point between the stainless steel tube 6 and the discharge end 101 under the current condition is broken down to form a discharge channel, and the sectional area of the channel is small, so the discharge time is extremely short, and the energy is highly concentrated (10) ⁶ W/cm ² ) The instantaneous high temperature generated in the discharge area is enough to melt and even evaporate the metal on the surface of the stainless steel pipe 6, so that a small pit is formed; after the first pulse discharge is finished, and a short interval time is passed, the second pulse is subjected to breakdown discharge at the closest point between the two electrodes, so that the high-frequency cycle is repeated, the tool electrode 1 is continuously fed to the stainless steel tube 6, the shape of the tool electrode is finally copied on the stainless steel tube 6, and a required machining surface is formed; in the machining process, although a small part of the total energy is also released to the tool electrode 1 to cause the loss of the tool electrode 1, the discharging end 101 of the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6, and the working end 102 at the discharging end 101 continuously changes positions, so that the loss of the tool electrode 1 is reduced by avoiding the continuous machining of the working end 102, and further, the working end 102 of the discharging end 101 keeps a complete shape at each time of machining, and the machining precision is improved.

Illustratively, during the machining, the electrical parameters satisfy:

Specifically, during machining, the tool electrode 1 is controlled by the machine tool to move eccentrically, and the stainless steel pipe 6 is kept stationary.

The tool electrode 1 is connected with a driving device arranged on a machine tool, the driving device comprises a transmission rod 2, and when in machining, the machine tool controls the transmission rod 2 to swing, so that the tool electrode 1 is driven to do eccentric motion through the transmission rod 2;

specifically, the transmission rod 2 swings clockwise in a swing plane YZ, and the swing plane YZ is parallel to a plane where the discharge end 101 is located, so that the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6.

Illustratively, during the machining process, the non-electrical parameters satisfy:

Therefore, the discharge end 101 of the tool electrode 1 eccentrically moves for a circle around the central axis of the inner cavity of the stainless steel tube 6, so that the machining of the stainless steel tube fracture groove 601 can be completed, the one-time machining in place is realized, and the machining efficiency is obviously improved.

In order to better utilize the processing method to process the V-shaped groove of the ultra-long thin-walled tube, the invention also provides a processing device which comprises a tool electrode 1 arranged on a machine tool, a universal adjustable clamp used for aligning the tool electrode, a driving assembly used for controlling the tool electrode to be in an eccentric motion state and a bearing assembly used for clamping the thin-walled tube, so that the problem that the V-shaped groove of the ultra-long thin-walled tube is difficult to be processed on the ultra-long thin-walled tube at high precision in the prior art is solved by carrying out electric spark processing on the V-shaped groove of the ultra-long thin-walled tube by the tool electrode 1.

One end of the tool electrode 1 is a discharge end 101, the discharge end comprises a plurality of electric spark machining points circumferentially arranged around the thin-walled tube, and the same electric spark machining point comprises a working state and a non-working state;

the threshold is a discharge distance between an electric discharge machining point and a surface to be machined, which meets machining requirements, and is 0-50 μm in an exemplary manner.

The V-shaped groove on the surface to be machined is machined by the working state of a plurality of electric spark machining point positions arranged around the circumference of the thin-walled tube.

In a possible embodiment, one end of the tool electrode 1 is annular, that is, a plurality of electrical discharge machining points arranged around the circumference of the thin-walled tube form a continuous annular shape, the inner circle end of the annular shape matches with the shape of the V-shaped groove, that is, the inner circle end is convex, the V-shaped groove is concave, and the cross-sectional size of the convex shape is the same as the cross-sectional shape of the concave groove; the other end of the tool electrode 1 is a conductive end 104, and is electrically connected with an output end of a power supply device arranged on the machine tool, so as to introduce current and transmit the current to an inner circle end, at this time, the inner circle end is a discharge end 101, and the machining of the V-shaped groove on the surface to be machined is realized through the working state of a plurality of electric spark machining points of the discharge end 101, which are circumferentially arranged around the thin-walled tube.

In a possible embodiment, the discharge end is a rigid structure, and the discharge end 101 is sleeved on the outer end surface of the stainless steel tube 6; when in processing, the stainless steel tube 6 is electrically connected with the other output end of the power supply device, and the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6; wherein, in the process of the eccentric motion of the tool electrode 1, the distance between the inner circle end surface of the discharge end 101 and the end surface to be processed of the stainless steel tube 6 is constantly changed; when the distance between the electric spark machining point and the surface to be machined is greater than the threshold value, the electric spark machining point is in a non-working state, and at the moment, the electric spark machining point is a non-working end 103; when the distance between the electric spark machining point and the surface to be machined is smaller than or equal to the threshold value, the electric spark machining point is in a working state, and at the moment, the electric spark machining point is a working end 102, so that the working state and the non-working state are changed at the same electric spark machining point, the working states of all the electric spark machining points jointly realize machining of the broken groove on the surface to be machined, namely, the position of the working end 102 is continuously changed in the inner circular end surface of the discharge end 101, the circular discharge end of the tool electrode eccentrically moves for a circle around the central axis of the inner cavity of the stainless steel pipe, and all the working ends form continuous circular discharge ends around the stainless steel pipe in the circumferential direction, so that the discharge end 101 of the tool electrode 1 is prevented from being in a continuous machining state, and further the loss of the tool electrode 1 is reduced.

Wherein, in the process of the eccentric motion of the tool electrode 1, the distance between the end surface of the discharge end 101 and the end surface to be processed of the stainless steel tube 6 is constantly changed, the end surface with the distance of 10-50 μm is in a working state, namely the working end 102, and the end surface with the distance of more than 50 μm is in a non-working state, namely the non-working end 103. Wherein, the processing tracks of all the working ends 102 together form an ultra-long stainless steel pipe breaking groove 601.

Specifically, one end of the tool electrode 1 is mounted on the machine tool, the discharge end 101 of the tool electrode 1 is sleeved on the outer end face of the stainless steel tube 6, and the tool electrodeThe center of the inner circular end of the discharge end 101 of the electrode 1 coincides with the central axis of the inner cavity of the stainless steel tube 6, and an allowance gap is formed between the discharge end 101 and the outer end surface of the stainless steel tube 6, namely the diameter of the inner circular end of the discharge end 101 is larger than the outer diameter of the stainless steel tube 6, illustratively, the diameter of the inner circular end is 10-20mm, which is 5-10 times the outer diameter of the stainless steel tube 6. Thereby, during the electric discharge machining, the determination of the single-side feed amount O is facilitated ₁ O ₂ The value of (c). During machining, the tool electrode 1 is driven to swing through a machine tool, and at the moment, the discharge end 101 of the tool electrode 1 is in an eccentric motion state around the central axis of the inner cavity of the stainless steel pipe 6.

Wherein the one-side feed amount O ₁ O ₂ Satisfies the following conditions:

O ₁ O ₂ ＝S ₁ +(H ₁ -H ₂ )-S ₂

wherein, O ₁ Represents the center point of the discharge end 101 of the tool electrode;

O ₂ represents the center point of the inner cavity of the stainless steel pipe 6;

H ₁ the wall thickness of the stainless steel tube 6;

H ₂ the wall thickness of the breaking groove 601;

S ₂ the machining gap is the closest distance between the working end 102 and the end face of the stainless steel pipe 601 when the tool electrode 1 eccentrically moves;

S ₁ there is a margin gap between the discharge end 101 and the outer end surface of the stainless steel pipe 6.

Wherein S is ₁ Satisfies the following conditions:

wherein S is ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ The four points are evenly distributed on the discharge end 101 for the actual margin gap value between the discharge end 101 of the tool electrode and the outer end surface of the stainless steel tube 6.

Exemplary, S ₂ ＝10μm；H ₁ ＝0.5mm，H ₂ ＝0.3mm，S ₁ =2.058mm, at this time, O ₁ O ₂ ＝2.248mm。

Wherein, after the center of the discharge end 101 of the tool electrode 1 is adjusted by the machine tool to coincide with the central axis of the inner cavity of the stainless steel tube 6, the actually measured S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ The closer the four values of (1) are, the more precise the value of S1 and thus the one-sided feed O ₁ O ₂ The more accurate, the more accurate the machining gap can be ensured during the eccentric motion of the tool electrode 1, and the machining depth of the working end 101 can be further ensured, so as to ensure the dimensional accuracy of the machined breaking groove 601.

After the center of the discharge end 101 of the tool electrode 1 is adjusted to coincide with the central axis of the inner cavity of the stainless steel tube 6, the tool electrode 1 is in an eccentric motion state under the action of a machine tool, and the detailed process is shown below.

At the center point O of the discharge end 101 of the tool electrode 1 ₁ And the center O of the inner cavity of the stainless steel pipe 6 ₂ The motion trajectory of (a) is illustrated as follows:

With O ₂ Centered on O ₁ O ₂ To a radius, adding O ₁ Around O ₂ Rotation at this time, O ₁ The track of the movement is a circle,the center of the circle is O ₂ Radius of O ₁ O ₂ ；

Wherein in the movement of O ₁ When the shortest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10 μm, the power supply is started to supply pulse voltage to the tool electrode 1 and the stainless steel tube 6, and metal on the surface of the stainless steel tube 6 is etched at a processing speed of 0.04g/min until O is reached ₁ And O ₂ Has a distance of O ₁ O ₂ Then O is ₁ Around O ₂ Performing a circular motion.

At O ₁ Around O ₂ While rotating, at this time, O ₃ The trajectory of (a) is: with O ₃ Is taken as the center of a circle and takes O as the center ₁ O ₂ A circle with a radius;

wherein at O ₃ In the moving process, when the closest distance between the end face of the discharge end 101 and the surface of the stainless steel pipe 6 reaches 10 micrometers, a power supply device is started to transmit pulse voltage to the tool electrode 1 and the stainless steel pipe 6, and metal on the surface of the stainless steel pipe 6 is etched at a processing speed of 0.04g/min until O ₃ A moving distance of O ₁ O ₂ Then, O ₃ Then, the initial position is used as the center of a circle to do circular motion.

Therefore, in the process of the eccentric motion of the tool electrode 1, the distance between the inner circle end face of the discharge end 101 and the outer surface of the stainless steel tube 6 is continuously changed, the distance between each part of the inner circle end face of the discharge end 101 and the outer end face of the stainless steel tube 6 is changed from close to far, and further, the discharge end 101 is changed from the working state to the non-working state, namely, the dynamic change between the working end 102 and the non-working end 103 is realized, so that the working end 102 of the tool electrode 1 is prevented from being in a continuous machining state, and the loss of the working end 102 of the tool electrode 1 is greatly reduced.

Wherein, a margin gap S is arranged between the discharge end 101 and the outer end surface of the stainless steel pipe 601 ₁ The pulse voltage is used for ensuring that the non-processing gap between the non-working end 103 at the discharge end 101 and the end surface of the stainless steel tube 6 is large enough, and further ensuring that the pulse voltage released at the non-working end 103 cannot erode the metal on the surface of the stainless steel tube 6. Thus, dynamic switching between the working end 102 and the non-working end 103 is achieved when the tool electrode 1 is moved eccentrically.

The conductive end of the tool electrode 1 is electrically connected with one output end of a power supply device arranged on the machine tool, the stainless steel tube 6 is electrically connected with the other output end of the power supply device, the power supply device comprises a pulse power supply, and the two output ends of the pulse power supply are respectively connected with the positive electrode and the negative electrode of the pulse power supply and used for outputting pulse voltage.

Illustratively, during the machining process, the electrical parameters satisfy:

Specifically, the driving assembly comprises a transmission rod 2, one end of the transmission rod 2 is connected with the tool electrode 1 through a universal adjustable clamp, the other end of the transmission rod 2 is installed on a machine tool, the transmission rod 2 can be controlled to swing through the machine tool, and then the transmission rod 2 drives the discharge end 101 of the tool electrode 1 to do eccentric motion around the central axis of the inner cavity of the stainless steel pipe 6.

Specifically, the transmission rod 2 swings clockwise in a swing plane YZ, and the swing plane YZ is parallel to a plane where the discharge end 101 is located, so that the discharge end of the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6. Wherein the stainless steel pipe 6 is kept still during the processing.

the swing speed of the driving component is 0.4-0.6 rpm, the processing gap is 10-50 μm, the processing speed is 0.02-0.045 g/min, and the single-side feed amount is 2.214-2.2.316 mm.

Specifically, the universal adjustable fixture is connected with the tool electrode 1 and used for adjusting the control position of the tool electrode 1 to realize alignment of the tool electrode and ensure the machining precision.

The universal adjustable clamp comprises a clamping part for clamping the tool electrode 1, a first adjusting part for aligning the tool electrode 1 in the XY plane direction of the machine tool, and a second adjusting part for aligning the tool electrode 1 in the YZ plane direction of the machine tool, wherein the clamping part, the first adjusting part and the second adjusting part are sequentially connected with one another from bottom to top; in the alignment, the tool electrode 1 is first aligned in the XY plane direction of the machine tool by the first adjustment portion, and then the tool electrode 1 is aligned in the YZ plane direction of the machine tool by the second adjustment portion to ensure that the discharge end surface of the tool electrode 1 is perpendicular to the position to be machined of the stainless steel pipe.

Specifically, the clamping part includes a reference seat 10 and a clamping seat 11 installed on the reference seat 10, wherein a clamping space for installing the tool electrode 1 is provided between adjacent surfaces of the clamping seat 11 and the reference seat 10, and during installation, the upper end of the tool electrode 1 is installed in the clamping space so as to clamp the tool electrode 1.

Furthermore, the clamping part further comprises a fastening screw 12 for adjusting the clamping force of the tool electrode 1, the fastening screw 12 is screwed on the clamping seat 11, and one end of the fastening screw penetrates through the clamping seat 11 and is located in the clamping space. When the tool electrode 1 is installed, after the upper end of the tool electrode 1 is placed in the clamping space, the fastening screw 12 is rotated, and the end face of the tool electrode 1 is pressed by the fastening screw 12 to press the tool electrode 1 tightly to prevent the tool electrode 1 from sliding.

The inner end face of the clamping space connected with the tool electrode 1 is a V-shaped face, the upper end face of the tool electrode 1 is matched with the V-shaped face, and the angle of the V-shaped face is 90 degrees so as to prevent the tool electrode 1 from sliding in the horizontal direction in the process of pressing the tool electrode 1 by the fastening screw 12. Thus, the clamping of the tool electrode 1 is realized.

Specifically, the first adjusting part comprises a first fixed seat 13 and a second fixed seat 14 which are distributed up and down, the second fixed seat 14 is installed at the lower end of the first fixed seat 13 through a vertical screw 15, and a gap is formed between adjacent surfaces of the first fixed seat 13 and the second fixed seat 14; wherein, the one end of vertical screw 15 passes through first fixing base 13 and second fixing base 14 to with first fixing base 13 spiro union, and with second fixing base 14 sliding connection, be equipped with the nut in the bottom of vertical screw 15, with in the direction of perpendicular to second fixing base 14, carry out spacingly with adjusting the inclination of second fixing base 14 on the horizontal direction through rotatory vertical screw 15 to second fixing base 14.

Wherein, be equipped with four perpendicular screws 15, and vertical, even distribution is on first fixing base 13 to this, rotatory arbitrary perpendicular screw 15 can realize the inclination of local regulation second fixing base 14 on the horizontal direction. The top of the four vertical screws 15 is a rotating head, so that a force can be applied to rotate the vertical screws 15, and in an initial state, the same allowance gap is provided between the rotating heads of all the vertical screws 15 and the upper end surface of the first fixing seat, so as to ensure that the vertical screws 15 have a sufficient screwing space.

Illustratively, when the vertical screw 15 at the left end of the first fixing base 13 is rotated clockwise, the vertical screw 15 drives the left end of the second fixing base 14 to tilt downwards.

Illustratively, when the left end of the second fixed seat 14 is inclined downward, the tool electrode 1 is inclined rightward.

Specifically, the second adjustment portion includes the anchor clamps head 17, first connector 18, second connector 19 and rotor 20, wherein, anchor clamps head 17 is installed on the lathe, first connector 18 and anchor clamps head 17 fixed connection, rotor 20 is located between first connector 18 and the second connector 19, and the upper end of rotor 20 and first connector 18 are at the horizontal direction rotatable coupling, the lower extreme and the second connector 19 of rotor 20 are fixed to meet, the lower extreme of second connector 19 and the top fixed connection of first fixing base 13, with this, rotate in the horizontal direction through rotor 20, realize controlling second connector 19 and rotate at the horizontal plane, and then realize adjusting the position of first fixing base 13 in the horizontal direction, and then realize finding tool electrode 1 in the YZ direction of lathe.

The lower end of the first connecting body 18 is provided with a cavity for placing the rotating body 20, the rotating body 20 is placed in the cavity, and the upper end of the rotating body 20 is rotatably installed on the top wall of the cavity; one end of the rotating body 20 is provided with a corner adjusting bolt 21, one end of the corner adjusting bolt 21 is screwed on the rotating body 20, and the other end of the corner adjusting bolt 21 penetrates through the cavity wall of the first connecting body 18 and is positioned outside the first connecting body 18; a notch 22 is formed on the side end surface of the first connecting body 18 so that the rotation angle adjusting bolt 21 can slide in the notch 22 when the rotating body 20 rotates; the end part of the corner adjusting bolt 21, which is located outside the first connecting body 18, is a bolt head, and by rotating the bolt head, the corner adjusting bolt 21 can be close to or far away from the first connecting body in the direction towards the first connecting body, so that the pressing force of the corner adjusting bolt 21 on the first connecting body 18 can be adjusted, and the state of the rotating body 20 can be adjusted.

Furthermore, an angle value scale surface, namely a scale surface of a rotation angle, is arranged in the length direction of the notch 22, wherein the rotation angle adjusting bolt 21 is positioned in the middle of the notch 22 and is 0 degree, and when the rotation angle adjusting bolt 21 rotates clockwise, the maximum position of the rotation angle adjusting bolt 21 moving is 10-30 degrees; when the tool electrode 1 rotates anticlockwise, the maximum position of the rotation angle adjusting bolt 21 is-30 degrees to-10 degrees, so that the rotation angle of the rotating body 20 can be accurately adjusted, and the tool electrode 1 can be accurately adjusted.

wherein, the center of the rotating body 20 is used as the center of a circle, and the angle β pushed by the corner adjusting bolt 21 satisfies the following conditions:

v ₁ the speed of the dial indicator moving is shown;

t ₁ the time of dial indicator movement.

Specifically, one end of the transmission rod 2 is fixedly connected with the reference seat 10, and the transmission rod 2 is parallel to the central line of the discharge end 101 of the tool electrode 1; in the machining process, the other end of the transmission rod 2 is installed on a machine tool so as to move through the machine tool to drive the transmission rod 2 to swing, and then the tool electrode 1 and the universal adjustable fixture are driven to move through the transmission rod 2, so that the discharge end 101 of the tool electrode 1 can eccentrically move around the central axis of the inner cavity of the stainless steel tube 6.

Specifically, the bearing assembly comprises an equal-height positioning block 3 and an auxiliary bearing block 4 which are arranged on a machine tool; so as to place the stainless steel tube 6 on the equal-height positioning block 3 and the auxiliary bearing block 4 to clamp the stainless steel tube 6.

Specifically, two equal-height positioning blocks 3 are arranged, and the two equal-height positioning blocks 3 are respectively positioned on two sides of the position to be machined of the stainless steel tube 6, so that the stability of the position to be machined of the stainless steel tube 6 is ensured in the machining process. Illustratively, the distance between two equal-height positioning blocks 3 is 20-50mm.

Furthermore, the equal-height positioning blocks 3 are also provided with clamping plates 5, the clamping plates 5 cover the V-shaped grooves and are clamped on the equal-height positioning blocks 3 to limit the stainless steel pipes 6, and the stability of the stainless steel pipes 6 is further improved. Illustratively, the angle of the V-shaped groove is 60-90 degrees, and the depth is 5-10mm.

Specifically, after the tool electrode 1 is aligned, the positions of the equal-height positioning block 3 and the auxiliary bearing block 4 on the machine tool are adjusted by utilizing the XYZ axes of the machine tool so as to align the stainless steel tube 6, and ensure that the central axis of the inner cavity of the stainless steel tube 6 is superposed with the central line of the discharge end 101 of the tool electrode 1, so that the value of the unilateral feeding amount is determined, and the machining precision is further improved.

The alignment process of the stainless steel pipe 6 is as follows.

Firstly, fixing 2 equal-height positioning blocks 3 and 2 auxiliary supporting blocks 4 on a workbench 9 of a machine tool, and then utilizing a dial indicator pull gauge to align the side surface of the equal-height positioning blocks to be parallel to the X axis of the machine tool, wherein the parallelism error is less than or equal to 0.01mm.

Before the stainless steel tube 6 is placed on the equal-height positioning block 3, the stainless steel tube 6 penetrates into the discharge end 101 of the tool electrode 1, and then the stainless steel tube 6 is placed on the equal-height positioning block 3 and the auxiliary bearing block 4, so that the stainless steel tube 6 is aligned through the equal-height positioning block 3 and the auxiliary bearing block 4.

Compared with the prior art, the inclination angle of the tool electrode 1 on the horizontal plane is adjusted through the first adjusting part of the universal adjustable clamp; according to the detection value of the dial indicator and the moving time and speed of the dial indicator, the inclination angle of the tool electrode 1 on the YZ surface of the machine tool is determined, the angle scale value on the first connecting body 18 is compared, the corner adjusting bolt 21 is pushed to corresponding scales, the inclination angle of the tool electrode 1 on the YZ surface of the machine tool can be adjusted in a high-precision mode, the tool electrode 1 is aligned, operation is convenient, and machining efficiency and precision are improved.

When processing, the stainless steel pipe 6 with the ultra-long length is placed in the V-shaped grooves on the equal-height positioning blocks 3 and the auxiliary bearing blocks 4, the clamping plate 5 is utilized to limit the upper surface of the stainless steel pipe with the ultra-long length, the clamping and the positioning of the stainless steel pipe with the ultra-long length can be realized, the clamping is convenient, and the stability of the stainless steel pipe 6 with the ultra-long length in the processing process can be ensured.

The discharge end 101 of the tool electrode 1 is annular and is sleeved on the outer end face of the ultra-long stainless steel tube 6 to perform eccentric motion, in the process, the distance between the end face of the discharge end 101 and the end face to be processed of the ultra-long stainless steel tube 6 is changed continuously, the closer distance is a working end 102, and the farther distance is a non-working end 103, so that the outer end face of the ultra-long stainless steel tube 6 is subjected to electric spark processing through the working end 102; namely, along the machining direction, the position of the working end 102 is continuously changed on the inner circular end face of the discharge end 101, namely, when the inner circular end face of the discharge end 101 is close to the outer end face of the ultra-long stainless steel tube 6, the end face of the discharge end 101 is the working end 102, when the end face is far away from the outer end face of the ultra-long stainless steel tube 6, the end face is changed into the non-working end 103, and dynamic change between the working end 102 and the non-working end 103 is realized, so that the working end 102 of the tool electrode 1 is prevented from being in a continuous machining state, the loss of the working end 102 of the tool electrode 1 is greatly reduced, the loss of the tool electrode is less than or equal to 1%, and further the deformation of the working end face of the tool electrode 1 is reduced, thereby improving the machining precision of the breaking groove 601 of the ultra-long stainless steel tube.

According to the tool electrode 1, the discharging end 101 of the tool electrode 1 is sleeved on the ultra-long stainless steel pipe 6 to perform eccentric motion, when the tool electrode is machined, the distance between the discharging end 101 and the ultra-long stainless steel pipe 6 is reduced from large to small and then increased from small to large, metal debris is generated between the discharging end 101 and the stainless steel pipe 6 in the process of reducing the distance from large to small, at the moment, part of the metal debris can be discharged along with working liquid through a machining gap, in the process of reducing the distance from small to large, the distance between the discharging end 101 and the stainless steel pipe 6 can be increased by nearly 200 times, the efficiency of discharging the metal debris is remarkably improved, the phenomenon that the metal debris is accumulated at the discharging end 101 due to untimely discharging of the metal debris is avoided, the loss of the tool electrode 1 is reduced, and the risk that the tool electrode 1 is directly connected with the stainless steel pipe 6 through the metal debris to cause short circuit is avoided.

The discharge end 101 of the tool electrode 1 is sleeved on the ultra-long stainless steel pipe 6 to do eccentric motion, so that metal scraps can be efficiently discharged, and further, the electric spark machining can be performed with a small machining gap, so that the machining current and the machining voltage value can be reduced, the machining cost is reduced, and the fracture groove 601 with low surface roughness can be obtained.

The machining of the breaking grooves 601 with different wall thicknesses can be realized by adjusting the value of the single-side feeding amount, the machining of the sizes of different oblique angles alpha can be realized by adjusting the shape of the discharge end 101 of the tool electrode 1, and a foundation is laid for the rapid production and batch production of products.

The discharge end 101 of the tool electrode 1 eccentrically moves for a circle around the central axis of the inner cavity of the ultra-long stainless steel pipe 6, so that the processing of the broken groove 601 of the ultra-long stainless steel pipe can be completed, one-time processing is realized, and the processing efficiency is obviously improved.

The invention abandons the traditional turning mode for the ultra-long stainless steel pipe, utilizes the working end 102 of the tool electrode 1 to discharge and corrode and remove the metal on the surface of the ultra-long stainless steel pipe 6, and carries out the machining of the fracture groove 601, namely, in the machining process, the tool electrode 1 is not in contact with the surface of the ultra-long stainless steel pipe, thereby avoiding the deformation of the ultra-long stainless steel pipe and overcoming the damage problem of the cutting force to the ultra-long stainless steel pipe.

The invention utilizes the discharge end 101 of the tool electrode 1 to eccentrically move around the central axis of the inner cavity of the ultra-long stainless steel pipe to process the breaking groove 601 of the ultra-long stainless steel pipe, namely, the ultra-long stainless steel can realize the processing of the annular breaking groove 601 on the outer surface of the ultra-long stainless steel pipe without moving in the processing process, thereby overcoming the problem that the coaxiality of the ultra-long stainless steel pipe is deteriorated to influence the processing precision in the rotation process.

The discharging end 101 of the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel pipe 6, so that the single-side feeding amount of the end face of each position of the discharging end 101 is the same, the consistency of the processing depth of the breaking groove 601 is ensured, and the processing precision of the breaking groove 601 is improved.

Example 1

A method for processing a breaking groove of an ultra-long stainless steel pipe comprises the following steps:

step 1: aligning the tool electrode by using a universal adjustable clamp;

specifically, the spatial position of the tool electrode 1 is adjusted by the spatial position of the universally adjustable clamp 5.

The tool electrode 1 is fixed on a universal adjustable fixture 5, a dial indicator is used for aligning the tool electrode 1 to set a reference surface, and the universal adjustable fixture is adjusted to enable the relative position error of the tool electrode 1 and the XYZ axis of the machine tool to be less than or equal to 0.01mm.

Specifically, a reference surface in the XYZ three-dimensional direction is selected on the tool electrode 1, a gauge head of the dial gauge is respectively touched to the reference surface, then the dial gauge is moved, if the pointer on the dial gauge moves 0-10 μm, the precision meets the requirement, the alignment process is finished, if the pointer on the dial gauge moves more than 10 μm, the precision does not meet the requirement, the positions of the tool electrode in three dimensions on the machine tool are correspondingly adjusted by using the universal adjustable clamp until the pointer on the dial gauge moves 0-10 μm, and therefore the alignment of the tool electrode 1 is achieved.

The tool electrode is aligned in the three-dimensional directions of XYZ of the machine tool by using the dial indicator, and after alignment is completed, the value of the dial indicator moving in the three dimensions of XYZ of the dial indicator is an alignment error, namely a relative position error.

Among them, in three directions of XYZ axes of the machine tool, a facet can be machined on the tool electrode 1 as a reference surface.

Illustratively, the tool electrode 1 is aligned in the Z-axis direction of the machine tool by using a dial indicator; the method comprises the steps of taking the discharge end face 101 of a tool electrode 1 as a reference surface, touching the gauge head of a dial indicator to the horizontal plane of the upper end of a transmission rod 2, moving the dial indicator up and down, enabling the position of the tool electrode 1 in the Z-axis direction to meet requirements if the gauge needle of the dial indicator moves by 0-10 microns, adjusting the position of the tool electrode 1 through a first adjusting part of a universal adjustable clamp if the gauge needle of the dial indicator moves by more than 10 microns, and continuously detecting by using the dial indicator after adjustment until the dial indicator moves within 0-10 microns.

Wherein, the adjustment process of universal adjustable anchor clamps is as follows:

specifically, the tool electrode 1 is first mounted in the clamping portion, and the tool electrode is pressed with the fastening screw 12;

then, taking the discharge end face of the tool electrode 1 as a reference face, enabling a gauge head of a dial gauge to touch the reference face and move in the Z-axis direction of the machine tool, wherein if a gauge needle of the dial gauge moves by 0-10 microns, the position of the tool electrode does not need to be adjusted in the front-back direction of the XY face of the machine tool, and if the gauge needle of the dial gauge moves by more than 10 microns, the position of the tool electrode 1 needs to be adjusted through a first adjusting part;

in the process of moving the dial indicator upwards, if the pointer moves clockwise, the upper end of the tool electrode 1 inclines towards the reference surface, if the pointer moves anticlockwise, the upper end of the tool electrode 1 inclines towards the opposite direction of the reference surface, and at the moment, the upper and lower space positions of the vertical screws 15 close to the two sides of the discharge end surface are adjusted, so that the tool electrode 1 can be aligned in the front-back direction of the XY surface of the machine tool.

Wherein the vertical screw 15 at the higher end is rotated clockwise and the vertical screw 15 at the lower end is rotated counterclockwise to align the tool electrode 1 in the front-rear direction of the XY plane of the machine tool.

Then, with the upper end face of the second fixed seat 14 as a reference face, touching the gauge head of the dial gauge to the reference face and moving the dial gauge in the Y-axis direction of the machine tool, wherein if the gauge needle of the dial gauge moves 0-10 μm, the position of the tool electrode 1 does not need to be adjusted in the left-right direction of the XY face of the machine tool, and if the gauge needle of the dial gauge moves more than 10 μm, the position of the tool electrode 1 needs to be adjusted by the first adjusting part;

the upper end face of the tool electrode 1 is a plane parallel to the center line of the discharge end 101, the plane is connected with the lower end face of the insulating plate 16, the upper end face of the second fixing seat 14 is parallel to the upper end face of the tool electrode 1, and therefore the tool electrode 1 can be aligned in the left-right direction of the XY plane of the machine tool by taking the upper end face of the second fixing seat 14 as a reference plane.

In the process that the dial indicator moves rightwards, if the pointer moves clockwise, the right end of the second fixing seat 14 is higher, and at the moment, the vertical screw 15 close to the right end of the second fixing seat 14 can be adjusted to rotate clockwise, or the vertical screw 15 close to the left end of the second fixing seat 14 can be adjusted to rotate anticlockwise.

In the process that the dial indicator moves rightwards, if the pointer moves anticlockwise, the left end of the second fixing seat 14 is higher, at the moment, the vertical screw 15 close to the left end of the second fixing seat 14 can be adjusted to rotate clockwise, or the vertical screw 15 close to the right end of the second fixing seat 14 can be adjusted to rotate anticlockwise, so that the tool electrode can be aligned in the left and right directions of the XY surface of the machine tool.

Then, with the discharge end face of the tool electrode 1 as a reference surface, the gauge head of the dial indicator touches the reference surface and moves in the Y-axis direction of the machine tool; if the pointer of the dial indicator moves 0-10 mu m, the position of the tool electrode 1 does not need to be adjusted in the YZ plane direction of the machine tool, and if the pointer of the dial indicator moves more than 10 mu m, the position of the tool electrode needs to be adjusted through the second adjusting part;

in the process of moving the dial indicator to the right, if the pointer moves clockwise, the tool electrode 1 tilts in the clockwise direction, and at this time, the rotation angle adjusting bolt 21 rotates counterclockwise, and if the pointer moves counterclockwise, the tool electrode 1 tilts in the counterclockwise direction, and at this time, the rotation angle adjusting bolt 21 rotates clockwise.

The method comprises the steps of controlling the dial indicator to move in the three-dimensional directions of XYZ by using a machine tool, and recording the moving time and speed of the dial indicator so as to obtain the inclination of a tool electrode in the three-dimensional directions of XYZAnd (4) oblique angle. Wherein, in the YZ plane direction of the machine tool, the tool electrode 1 is aligned by using a dial indicator, and the movement time of the dial indicator is recorded as t ₁ Velocity v ₁ Clockwise rotation distance of a pointer of the dial indicator is S; if 0 μm<S<10 μm, in which case the angle adjusting bolt 21 need not be adjusted; if S>10 μm, the rotation angle adjusting bolt 21 needs to be adjusted counterclockwise, and the pushed angle β of the rotation angle adjusting bolt 21 with the center of the rotating body 20 as the center of the circle satisfies the following conditions:

when the corner adjusting bolt 21 needs to be pushed anticlockwise, the corner adjusting bolt 21 is firstly rotated anticlockwise to enable the corner adjusting bolt 21 to be movably connected with the first connecting body 18, then the corner adjusting bolt 21 is pushed anticlockwise, the pushing angle is-beta, in the process, adjustment is carried out according to the scales at the notch 22 of the first connecting body 18, the tool electrode 1 can be aligned in the YZ plane direction of the machine tool, and after alignment is finished, the corner adjusting bolt 21 is rotated clockwise to be tightly pressed on the end face of the first connecting body 18, so that the corner adjusting bolt 21 is prevented from sliding.

In this way, the alignment process of the tool electrode 1 is achieved.

Step 2: clamping the stainless steel pipe 6 by using the bearing assembly, and aligning the stainless steel pipe 6;

specifically, firstly, 2 equal-height positioning blocks 3 and 2 auxiliary supporting blocks 4 are fixed on a workbench 9, a dial indicator is utilized to align the side surfaces of the equal-height positioning blocks and the auxiliary supporting blocks to be parallel to the X axis of a machine tool, the machine tool is utilized to adjust the positions of the equal-height positioning blocks 3 and the auxiliary supporting blocks 4, and the error of parallelism is less than or equal to 0.01mm.

Then placing the stainless steel tube 6 on the equal-height positioning blocks 3, penetrating the stainless steel tube 6 through the inner round end at the lower end of the tool electrode 1 before placing, and ensuring that the stainless steel tube 6 is in a horizontal position through the equal-height positioning blocks 3, wherein the distance between 2 equal-height positioning blocks 3 is 30mm;

then, both ends of the stainless steel pipe 6 are placed on the auxiliary support blocks 4, and finally, fixed by the clamping plates 5.

And step 3: the center line of the discharge end 101 of the tool electrode 1 is adjusted by a machine tool to coincide with the central axis of the inner cavity of the stainless steel tube 6;

specifically, the position of the stainless steel tube 6 is adjusted by moving the bearing assembly in the X-axis direction by the machine tool, so that the position to be machined of the stainless steel tube 6 is located in the discharge end 101 of the tool electrode 1;

then, by means of the automatic centering module of the machine tool, measure S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ If the four values are equal or the error is within +/-0.02 mm, the center of the discharge end 101 of the tool electrode 1 is coincided with the central axis of the inner cavity of the stainless steel tube 6, and if the four values are not coincided, the position of the bearing assembly is continuously adjusted through a machine tool until the requirements are met.

And 4, step 4: kerosene and water were used as working liquids, and the stainless steel pipe 6 was subjected to electric discharge machining using the tool electrode 1 in the working liquid.

S101: controlling the discharge end 101 of the tool electrode 1 to eccentrically move around the central axis of the inner cavity of the stainless steel pipe 6;

specifically, the machine tool drives the transmission rod 2 to swing on a YZ plane, and then the discharge end 101 of the tool electrode 1 is controlled by the transmission rod 2 to perform eccentric motion around the central axis of the inner cavity of the stainless steel tube 6; the direction of eccentric movement 8 is shown in fig. 10.

Wherein the swing speed of the transmission rod 2 is 0.5rpm;

S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ the actual measurement values were 2.055mm, 2.060mm, 2.065mm, and 2.050mm, respectively, at which time S ₁ ＝2.058mm；

Machining gap S ₂ Is 10 μm;

single side feed O ₁ O ₂ ＝S ₁ +(H ₁ -H ₂ )-S ₂ ＝2.058+(0.5-0.3)-0.01＝2.248mm；

The processing speed was 0.04g/min.

S102: when the tool electrode 1 is eccentrically moved, the tool electrode 1 is energized to perform electric discharge machining.

Specifically, the electrical parameters satisfy:

pulse width 40 μ s, pulse interval 26 μ s, average machining current 1A, and average machining voltage 40V.

Therefore, the discharging end of the tool electrode eccentrically moves for a circle around the central axis of the inner cavity of the stainless steel pipe, so that the machining of the stainless steel pipe fracture groove can be completed, the one-time machining in place is realized, and the machining efficiency is obviously improved.

The #01- #10 pieces of ultra-long stainless steel pipes were subjected to the break groove processing by the above processing method, and the processing parameters are shown in table 1 below.

TABLE 1 processing parameters

Processing requirements are as follows: the wall thickness of the breaking groove is 0.3 +/-0.05 mm, and the oblique angle alpha is 90 degrees.

The results of the measurements are shown in Table 2 below.

TABLE 2 test results

Wherein, the electrode consumption ratio is E/W100%, wherein E is the diameter size variation of the discharge end of the tool electrode, and W is the initial diameter size of the inner circle end of the tool electrode.

As can be seen from table 2, the average value of the groove depth of the breaking groove of 10 stainless steel pipes processed by the method of the present invention is 0.2146mm, the standard deviation is 0.01427, the dispersion coefficient is 0.07, the breaking groove angles are 90 °, the average value of the wall thickness of the breaking groove is 0.299mm, the standard deviation is 0.006681, and the dispersion coefficient is 0.02.

Those skilled in the art will appreciate that all or part of the flow of the method implementing the above embodiments may be implemented by a computer program, which is stored in a computer readable storage medium, to instruct related hardware. The computer readable storage medium is a magnetic disk, an optical disk, a read-only memory or a random access memory.

While the invention has been described with reference to specific preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. The processing method of the V-shaped groove of the ultra-long thin-walled tube is characterized by comprising the following steps of:

step 1: aligning the tool electrode by using a universal adjustable clamp;

and 3, step 3: the machining of the V-shaped groove on the surface to be machined is realized by utilizing the working state of a plurality of electric spark machining point positions of the tool electrode, which are circumferentially arranged around the thin-walled tube;

2. The method of claim 1, wherein: the universal adjustable clamp comprises a clamping part for clamping a tool electrode, a first adjusting part for aligning the tool electrode on the XY surface of the machine tool, and a second adjusting part for aligning the tool electrode on the YZ surface of the machine tool;

3. The method of claim 2, wherein step 1 comprises:

4. The method according to claim 3, wherein the step S13 comprises:

5. The method of claim 4, wherein: in step S132, the surface on which the scales are provided on the end surface of the first connecting body is used as a reference surface, and the corner adjusting bolt is pushed by an angle β;

s is the movement distance of a pointer of a dial indicator when the inclination angle of the tool electrode is detected in the direction of a YZ plane of the machine tool; v. of ₁ The speed of the dial indicator moving is shown; t is t ₁ The time of dial indicator movement.

6. The method of claim 3, wherein: the center line of the discharge end of the tool electrode is parallel to the upper end surface and the lower end surface of the second fixing seat, and the tool electrode moves synchronously when the second fixing seat is adjusted.

7. The method of claim 1, wherein: one end of the tool electrode is a discharge end, the discharge end comprises a plurality of electric spark machining point positions arranged around the circumference of the thin-walled tube, when in machining, the plurality of electric spark machining point positions arranged around the circumference of the thin-walled tube form a continuous ring shape, and the inner circular end of the ring is matched with the V-shaped groove in shape;

the discharge end of the tool electrode is sleeved on the thin-walled tube, and during machining, the discharge end of the tool electrode eccentrically moves around the central axis of the inner cavity of the thin-walled tube.

8. The method of claim 7, wherein: when the discharge end of the tool electrode performs eccentric motion around the central axis of the inner cavity of the thin-walled tube for processing, the single-side feed O ₁ O ₂ Satisfies the following conditions:

O ₁ O ₂ ＝S ₁ +(H ₁ -H ₂ )-S ₂

wherein H ₁ The wall thickness of the thin-walled tube; h ₂ The wall thickness of the V-shaped groove; s ₁ The distance between the discharge end of the tool electrode and the surface to be processed is the distance before processing;S ₂ to machine the gap.

9. The method of claim 7, wherein: the driving component is used for driving the discharge end of the tool electrode to perform eccentric motion around the central axis of the inner cavity of the thin-walled tube;

wherein the non-electrical parameters satisfy:

Wherein the electrical parameter satisfies:

10. The method of claim 6, wherein the step 2 comprises:

s21: fixing the bearing component on a workbench of a machine tool, and aligning the bearing component by using the machine tool;