CN115971590A

CN115971590A - Machining device and method for breaking groove of ultra-long stainless steel pipe

Info

Publication number: CN115971590A
Application number: CN202211540089.1A
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: 2023-04-18

Abstract

The invention relates to a device and a method for machining a breaking groove of an ultra-long stainless steel pipe, belongs to the technical field of ultra-long pipe fitting machining, and solves the problem that the breaking groove is difficult to be machined on the ultra-long stainless steel pipe at high precision in the prior art. The machining device comprises a tool electrode arranged on a machine tool, a bearing assembly used for clamping a stainless steel pipe and a driving assembly used for controlling the moving state of the tool electrode; one end of the tool electrode is a discharge end, the discharge end comprises a plurality of electric spark machining points which are circumferentially arranged around the stainless steel, and the same electric spark machining point comprises a working state and a non-working state; and machining the fracture groove on the surface to be machined by the working state of a plurality of electric spark machining point positions arranged around the circumference of the stainless steel pipe. The method realizes high-precision machining of the breaking groove of the ultra-long stainless steel pipe, can be machined in place at one time, and obviously improves the machining efficiency.

Description

Machining device and method for breaking groove of ultra-long stainless steel pipe

Technical Field

The invention relates to the technical field of processing of ultra-long and ultra-long pipe fittings, in particular to a device and a method for processing a breaking groove of an ultra-long and ultra-long stainless steel pipe.

Background

The method comprises the following steps that (1) breaking grooves need to be processed on some ultra-long and slender flying products, and the breaking grooves are used for separating a flying product guiding system from a product fairing body when the products reach a preset height and position; because the ultra-slender flight navigation product has the characteristics of small diameter and thin wall thickness, the size of the fracture groove processed on the ultra-slender flight navigation product is smaller. For the flight products with the size which is vital to control, the machining precision requirement of the breaking groove puts higher requirements on the machining mode of the breaking groove.

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

Therefore, in order to meet the machining requirements of the break groove in the ultra-long aviation product, a new break groove machining device and a new break groove machining method need to be searched.

Disclosure of Invention

In view of the above analysis, the embodiments of the present invention are directed to a device and a method for processing a breaking groove of an ultra-long stainless steel tube, so as to solve the problem that it is difficult to process a breaking groove on an ultra-long stainless steel tube with high precision.

On one hand, the embodiment of the invention provides a machining device for a breaking groove of an ultra-long stainless steel pipe, which comprises a tool electrode, a bearing assembly and a driving assembly, wherein the tool electrode is arranged on a machine tool;

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 stainless steel pipe, and the same electric spark machining point comprises a working state and a non-working state;

and machining the broken groove on the surface to be machined by the working state of the electric spark machining points which are circumferentially arranged around the stainless steel pipe.

Based on the further improvement of the device, the bearing assembly comprises an equal-height positioning block, an auxiliary positioning block and a clamping plate which are arranged on a machine tool;

the equal-height positioning blocks and the auxiliary supporting blocks are used for clamping the stainless steel pipes;

the clamping plate is clamped on the equal-height positioning block and used for limiting the stainless steel pipe;

the equal-height positioning blocks and the auxiliary positioning blocks can be adjusted in position on the machine tool.

Based on the further improvement of the device, the bearing assembly comprises two equal-height positioning blocks and two auxiliary bearing blocks;

the two equal-height positioning blocks are respectively positioned on two sides of the position to be processed of the stainless steel pipe and positioned between the two auxiliary bearing blocks;

wherein, the distance between the two equal-height positioning blocks is 20-50mm.

Based on the further improvement of the device, the upper end surfaces of the equal-height positioning blocks and the auxiliary bearing blocks are flush, and the upper end surfaces of the equal-height positioning blocks and the auxiliary bearing blocks are provided with V-shaped grooves for placing stainless steel pipes so as to limit the stainless steel pipes.

Based on further improvement of the device, 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.

Based on the further improvement of the device, a plurality of electric spark machining point positions arranged around the circumference of the stainless steel pipe are continuously distributed around the circumference of the stainless steel pipe in an uninterrupted manner.

Based on the further improvement of the device, a plurality of electric spark machining point positions arranged around the circumference of the stainless steel pipe form a continuous ring shape, and the inner circle end of the ring is matched with the shape of the breaking groove.

Based on the further improvement of the device, the annular discharge end of the tool electrode is of a rigid structure and is sleeved on the stainless steel pipe, and during machining, the annular discharge end of the tool electrode makes eccentric motion around the central axis of the inner cavity of the stainless steel pipe.

Based on the further improvement of the device, the driving assembly comprises a transmission rod, one end of the transmission rod is connected with the tool electrode, and the other end of the transmission rod is installed on a machine tool during machining so as to drive the transmission rod to swing through the machine tool to drive the discharge end of the tool electrode to perform eccentric motion around the central axis of the inner cavity of the stainless steel pipe.

On one hand, the embodiment of the invention also provides a processing method of the breaking groove of the ultra-long stainless steel pipe, which comprises the steps that the processing device processes the breaking groove of the stainless steel pipe;

wherein, when processing, the non-electric parameter satisfies:

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

wherein, during processing, the electrical parameters satisfy:

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.

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

1. when the invention is processed, the clamping and positioning of the ultra-long stainless steel pipe can be realized only by placing the ultra-long stainless steel pipe in the V-shaped grooves on the equal-height positioning blocks and the auxiliary bearing blocks and limiting the upper surface of the ultra-long stainless steel pipe by using the clamping plate, the clamping and the positioning are convenient, and the stability of the ultra-long stainless steel pipe in the processing process can be ensured

2. The tool electrode has a circular discharge end which is sleeved on the outer end face of the ultra-thin stainless steel pipe to perform eccentric motion, in the process, the distance between the end face of the discharge end and the end face to be processed of the ultra-thin stainless steel pipe is continuously changed, the end face with the closer distance is a working end, and the end face with the farther distance is a non-working end, so that the outer end face of the ultra-thin stainless steel pipe is subjected to electric spark processing through the working end; along the direction of processing promptly, the position of working end constantly changes on the interior circle terminal surface of discharge end, when the interior circle terminal surface of discharge end is close to the outer terminal surface of super long stainless steel pipe promptly, the terminal surface of this discharge end is the working end, when the outer terminal surface of super long stainless steel pipe is kept away from to this terminal surface, this terminal surface changes into non-working end, dynamic transition between working end and the non-working end has been realized, with this, the working end of having avoided tool electrode is in lasting processing state, greatly reduced the loss to the working end of tool electrode, it is less than or equal to 1% to have realized that tool electrode loss, and then reduced tool electrode's working end face deformation, with this precision to super long stainless steel pipe rupture groove processing has been improved.

3. The discharge end of the tool electrode is sleeved on the ultra-long stainless steel pipe to perform eccentric motion, when the tool electrode is machined, the distance between the discharge end and the ultra-long stainless steel pipe is reduced from large to small and then increased from small to large, metal debris can be generated between the discharge end and the stainless steel pipe 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 discharge end and the stainless steel pipe 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 direct connection of the tool electrode and the stainless steel pipe through the metal debris is avoided.

4. The discharge end sleeve of the tool electrode can perform eccentric motion on the ultra-long stainless steel pipe, metal scraps can be efficiently discharged, and then electric spark machining is performed with a small machining gap, so that machining current and machining voltage values can be reduced, machining cost is reduced, and a fracture groove with low surface roughness can be obtained.

5. 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.

6. The invention utilizes the discharge end of the tool electrode to eccentrically move 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 of the ultra-long stainless steel pipe without rotating in the processing process, and the problem that the processing precision is influenced by the coaxiality of the ultra-long stainless steel pipe in the rotation process is solved.

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

8. 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 surface at each position of the discharge 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.

9. The discharging end of the tool electrode is the same as the breaking groove in shape, namely the discharging end is convex, the breaking groove is concave, the cross section of the convex is the same as the cross section of the concave, therefore, after the tool electrode eccentrically moves for a circle around the central axis of the inner cavity of the ultra-long stainless steel tube, the depth and the oblique angle of the processed breaking groove are the required depth and oblique angle of the breaking groove, and the processing precision is obviously improved.

10. The machining of the broken grooves 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 of the tool electrode, and a foundation is laid for the rapid production and batch production of products.

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

FIG. 2 is a schematic view of a tool electrode configuration of the present invention;

FIG. 3 isbase:Sub>A schematic cross-sectional view taken at A-A in FIG. 2;

FIG. 4 is a schematic cross-sectional view taken at B-B of FIG. 2;

FIG. 5 is a schematic structural diagram of the tool electrode of the present invention when the center line of the discharge end coincides with the central axis of the inner cavity of the stainless steel tube;

FIG. 6 is a schematic structural diagram of the tool electrode of the present invention with its center line offset from the central axis of the inner cavity of the stainless steel tube;

FIG. 7 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. 8 is a central point O of the discharge end of the tool electrode of the present invention when the discharge end eccentrically moves around the central axis of the inner cavity of the stainless steel tube ₂ Schematic diagram of motion trail of;

FIG. 9 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. 10 is a schematic structural view of a stainless steel pipe rupture groove according to the present invention;

FIG. 11 is a schematic view of the structure of the positioning blocks, clamping plates and stainless steel tubes of the present invention;

FIG. 12 is a schematic view of the structure of the auxiliary bearing block and the stainless steel tube;

FIG. 13 is a schematic view of a stainless steel pipe after being processed into a break 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 table; 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. During processing, a breaking groove is generally needed to be processed on the ultra-long steel pipe, and the breaking groove is used for separating the flying product guiding system from the product fairing body when the 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 position of the breaking groove is thinner, if the wall thickness of the position 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 a V-shaped 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, and the reason is that the centrifugal force of the workpiece rotating caused by the overlong length in the rotating process is larger, the coaxiality of the workpiece is poorer, 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 machining device for a breaking groove of an ultra-long stainless steel pipe, which comprises a tool electrode, a bearing assembly and a driving assembly, wherein the tool electrode is arranged on a machine tool;

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 stainless steel pipe 6, and the same electric spark machining point comprises a working state and a non-working state;

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;

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 machining of the fracture groove on the surface to be machined is realized by the working state of a plurality of electric spark machining points circumferentially arranged around the stainless steel pipe 6.

It can be understood that the discharge end 101 includes a plurality of electrical discharge machining points circumferentially arranged around the stainless steel tube, and the plurality of electrical discharge machining points circumferentially arranged around the stainless steel tube may be continuously and circumferentially distributed around the stainless steel tube, or may be discontinuously distributed around the stainless steel tube, so that continuous machining and forming of the break 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 stainless steel tube form a continuous annular shape, as shown in fig. 2-7, the inner circle end of the annular shape matches with the shape of the breaking groove 601, that is, the inner circle end is convex, the breaking groove 601 is concave, and the cross-sectional dimension 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 to an output end of a power supply device arranged on the machine tool, so as to introduce current and transmit the current to the inner circle end, and at this time, the inner circle end is a discharge end 101, so as to realize the machining of the fracture groove on the surface to be machined through the working state of a plurality of electric spark machining points of the discharge end 101, which are circumferentially arranged around the stainless steel 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 electrical discharge machining point and the surface to be machined is smaller than or equal to the threshold value, the electrical discharge machining point is in a working state, and at the moment, the electrical discharge machining point is a working end 102, so that the working state and the non-working state are converted in the same electrical discharge machining point, the working states of all the electrical discharge machining points jointly realize the machining of the broken groove on the surface to be machined, namely, the position of the working end 102 is changed continuously 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 tube, and all the working ends form continuous circular discharge ends around the circumferential direction of the stainless steel tube, so that the discharge end 101 of the tool electrode 1 is prevented from being in a continuous machining state, and the loss of the tool electrode 1 is further 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, in the machining process, the tool electrode 1 is not in contact with the surface of the stainless steel pipe 6, so that the stainless steel pipe 6 is not deformed, the annular fracture groove 601 can be machined on the outer surface of the stainless steel pipe 6 without moving in the machining process, and the problem that the machining precision is influenced due to the fact that the coaxiality of the stainless steel pipe 6 is poor in the rotation process is solved; the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel pipe 6 for a circle, so that the machining of the stainless steel pipe fracture groove 601 can be completed, one-time machining in place is realized, and the machining efficiency is obviously improved; and the discharge end 101 of the tool electrode 1 is annular 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 with the shorter distance is the working end 102, the end face with the longer distance 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, the working end 102 of the tool electrode 1 is prevented from being in a continuous machining state, the loss of the tool electrode 1 is greatly reduced, the loss of the tool electrode is not more than 1%, and further, and the broken groove machining precision of the ultra-fine stainless steel tube is improved.

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 machined 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. Thus, the dynamic transition between the working end 102 and the non-working end 103 prevents the discharge end 101 of the tool electrode 1 from being in a continuous machining state, thereby reducing wear on the tool electrode 1.

Specifically, one end of the tool electrode 1 is mounted on a machine tool, the discharge end 101 of the tool electrode 1 is sleeved on the outer end surface of the stainless steel tube 6, 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, 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, as shown in FIG. 5, S 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 ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ 2.055mm, 2.060mm, 2.065mm, 2.050mm, respectively, at which time 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 can be ensured during the eccentric movement of the tool electrode 1, and the machining depth of the working end 101 can be 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:

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. 8, 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.

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 During rotation, at this time, O is shown in FIG. 9 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 When the end face of the discharge end 101 is 10 μm away from the surface of the stainless steel tube 6 during the movement, the power supply is turned on to supply power to the tool electrode 1The stainless steel pipe 6 is sent with pulse voltage and the metal on the surface of the stainless steel pipe 6 is etched at the 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, 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, 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 tube 6.

Specifically, the transmission rod 2 swings clockwise in a swing plane ZY which is parallel to the 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.

Illustratively, during processing, 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, the processing speed is 0.02-0.045 g/min, and the single-side feed amount is 2.214-2.2.316mm.

Specifically, the bearing assembly comprises an equal-height positioning block 3 and an auxiliary supporting block 4 which are arranged on a machine tool, so that the stainless steel pipe 6 is placed on the equal-height positioning block 3 and the auxiliary supporting block 4 to clamp the stainless steel pipe 6.

Specifically, as shown in fig. 1, 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 the two equal-height positioning blocks 3 are positioned between the two auxiliary bearing blocks 4 so as to support and position the two ends of the stainless steel tube 6 through the two auxiliary bearing blocks 4, thereby further ensuring the stability of the stainless steel tube 6 in the machining process.

As shown in fig. 10 to 12, the upper end surfaces of the equal-height positioning block 3 and the auxiliary bearing block 4 are flush, V-shaped grooves are formed in the upper end surfaces 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 grooves to limit the position of 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, the tool electrode 1 needs to be centered and aligned, then, the stainless steel tube 6 penetrates 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 stainless steel tube 6 is aligned through the equal-height positioning block 3 and the auxiliary bearing block 4.

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 unilateral feeding amount O can be conveniently determined ₁ O ₂ Further, the machining accuracy is 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.

Wherein, one end of the transmission rod 2 is connected with the tool electrode 1 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 so as to move through the machine tool to drive the transmission rod 2 to swing, and then the transmission rod 2 drives the tool electrode 1 to move, 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.

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 addition, the invention also provides a method for processing the breaking groove of the ultra-long stainless steel pipe, which comprises the step of carrying out electric spark processing on the breaking groove of the stainless steel pipe by using the processing device so as to solve the problem that the high-precision processing of the breaking groove on the ultra-long stainless steel pipe is difficult to realize in the prior art.

Specifically, the method comprises the step of machining the fracture groove on the surface to be machined by utilizing the working state of a plurality of electric spark machining points of the tool electrode 1, which are circumferentially arranged around the stainless steel pipe.

One end of the tool electrode is a discharge end, the discharge end comprises a plurality of electric spark machining points arranged around the circumference of the stainless steel, and the same electric spark machining point comprises a working state and a non-working state;

The discharge end 101 comprises a plurality of electrical discharge machining points circumferentially arranged around the stainless steel pipe, the plurality of electrical discharge machining points circumferentially arranged around the stainless steel pipe can be continuously distributed circumferentially around the stainless steel pipe or discontinuously distributed circumferentially around the stainless steel pipe, and continuous machining and forming of the broken 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 stainless steel tube form a continuous annular shape, the inner circle end of the annular shape matches with the shape of the breaking groove 601, that is, the inner circle end is convex, the breaking groove 601 is concave, and the cross-sectional dimension 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 to an output end of a power supply device arranged on the machine tool, so as to introduce current and transmit the current to the inner circle end, and at this time, the inner circle end is a discharge end 101, so as to realize the machining of the fracture groove on the surface to be machined through the working state of a plurality of electric spark machining points of the discharge end 101, which are circumferentially arranged around the stainless steel tube.

In a possible embodiment, the discharge end is a rigid structure, and the discharge end 101 is sleeved on the outer end face 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.

After the tool electrode 1 eccentrically moves for one circle, all end surfaces of the discharge end 101 participate in the electric spark machining, that is, all the working ends 102 form the complete discharge end 101, and the machining tracks of all the working ends 102 jointly form the super-long stainless steel pipe break groove 601; 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.

Specifically, the tool electrode 1 is mounted on a machine tool, and during machining, the machine tool drives the tool electrode 1 to perform eccentric motion, so that 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 an allowance gap is formed between the discharge end 101 and the outer end surface of the stainless steel tube 6, that is, the diameter of the inner circular end of the discharge end 101 is larger than the outer diameter of the stainless steel tube 6, and exemplarily, 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).

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;

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 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 moves eccentrically.

Wherein S is ₁ Satisfies the following conditions:

wherein S is ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ Four points are uniformly distributed on the discharge end 101 for actual allowance gap values between the discharge end 101 of the tool electrode 1 and the outer end surface of the stainless steel pipe 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 (a) 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 The same applies, 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 be a radius, adding O ₁ Around O ₂ Rotation at this time, O ₁ The moving track is a circle, and the center of the circle is O ₂ Radius of O ₁ O ₂ ；

Wherein in the movement of O ₁ When the closest 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 ₁ And O ₂ Has a distance of O ₁ O2, then O ₁ Around O ₂ Performing a circular motion.

At O ₁ Around O ₂ At the time of rotation, 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 circular motion is performed by taking the initial position as the center of a circle.

Therefore, 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 outer surface of the stainless steel tube 6 is changed continuously, the distance between each part of the inner circle 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.

A margin gap is formed between the discharge end 101 and the outer end surface of the stainless steel pipe 601 to ensure that a non-machining gap between the non-working end 103 of the discharge end 101 and the end surface of the stainless steel pipe 6 is sufficiently large, so as to ensure that the pulse voltage released from the non-working end 103 cannot corrode metal on the surface of the stainless steel pipe 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; during 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 working end 102 at the discharging end 101 is constantly changed in position by the eccentric motion of the discharging end 101 of the tool electrode 1 around the central axis of the inner cavity of the stainless steel tube 6, so that the continuous machining of the working end 102 is avoided to reduce the pair number of the tool electrode 1The loss of the tool electrode 1 and further the working end 102 of the discharge end 101 maintains a relatively complete shape at each time of machining, thereby improving the machining precision.

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 ZY which is parallel to the 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:

the swing speed of the transmission rod 2 is 0.4-0.6 rpm, the processing clearance is 10-50 μm, the processing speed is 0.02-0.045 g/min, and the single-side feed amount is 2.214-2.2.316mm.

Specifically, the stainless steel tube 6 is placed on the equal-height positioning block 3 and the auxiliary bearing block 4 to clamp the stainless steel tube 6.

The two equal-height positioning blocks 3 are used for clamping two sides of the position to be machined of the stainless steel pipe 6 respectively, so that the stability of the position to be machined of the stainless steel pipe 6 is ensured in the machining process. Illustratively, the distance between two equal-height positioning blocks 3 is 30mm.

The two equal-height positioning blocks 3 are positioned between the two auxiliary bearing blocks 4, and the two ends of the stainless steel tube 6 are supported and positioned by the two auxiliary bearing blocks 4, so that the stability of the stainless steel tube 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.

Further, cover grip block 5 on V type groove to the joint is on equal altitude locating piece 3, in order to carry on spacingly to stainless steel pipe 6, further improves stainless steel pipe 6's stability. 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 blocks 3, firstly, the tool electrode 1 needs to be centered and aligned by using a machine tool, then the stainless steel tube 6 penetrates into the discharge end 101 of the tool electrode 1, finally, the equal-height positioning blocks 3, the auxiliary bearing blocks 4 and the clamping plates 5 are used for clamping the stainless steel tube 6, and the stainless steel tube 6 is aligned through the equal-height positioning blocks 3 and the auxiliary bearing blocks 4.

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

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.

Wherein, one end of the transmission rod 2 is connected with the tool electrode 1 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 so as to move through the machine tool to drive the transmission rod 2 to swing, and then the tool electrode 1 is 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.

Compared with the prior art, 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, so that the deformation of the ultra-long stainless steel pipe can not be caused, and the problem of the damage of the cutting force to the ultra-long stainless steel pipe is solved.

The invention utilizes the eccentric motion of the discharge end 101 of the tool electrode 1 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.

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

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 finished, one-time processing in place is realized, and the processing efficiency is obviously improved.

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.

The shape of the discharge end 101 of the tool electrode 1 is the same as that of the breaking groove 601, that is, the discharge end 101 is convex, the breaking groove 601 is concave, and the size of the convex cross section is the same as that of the concave cross section, so that after the discharge end 101 of the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the ultra-long stainless steel tube 6 for one circle, the depth and the oblique angle of the machined breaking groove 601 are the depth and the oblique angle of the required breaking groove 601, and the machining precision is obviously improved.

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.

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.

Example 1

The utility model provides a processingequipment of super thin and long stainless steel pipe rupture groove, is including installing tool electrode 1, carrier assembly and the drive assembly on the lathe, and wherein, carrier assembly is used for the stainless steel pipe 6 of clamping, and drive assembly is used for driving tool electrode 1 around the eccentric motion of stainless steel pipe 6's inner chamber axis to realize carrying out spark-erosion machining to the rupture groove 601 of stainless steel pipe, solve the current problem that is difficult to realize processing the rupture groove on super long and thin stainless steel pipe.

Specifically, one end of the tool electrode 1 is annular, the inner circular end of the annular is the same as the shape of the breaking groove 601, the other end of the tool electrode 1 is a conductive end 104, and the conductive end is electrically connected with one output end of a power supply device arranged on the machine tool and used for introducing current and transmitting the current to the inner circular end, at this time, the inner circular end is a discharge end 101, and the discharge end 101 is sleeved on the outer end face 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 discharge end 101 of the tool electrode 1 eccentrically moves around the central axis of the inner cavity of the stainless steel tube 6, at this time, the discharge end 101 comprises a working end 102 and a non-working end 103, so that when in processing, the working end 102 is used for discharging and corroding metal on the surface of the stainless steel tube 6.

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.

Wherein, the center of the inner circle 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, and a margin gap is arranged between the discharge end 101 and the outer end surface of the stainless steel tube 6, wherein the diameter of the end surface of the discharge end 101 is 20mm, which is 10 times of the outer diameter of the stainless steel tube 6, so as to determine the unilateral feeding O ₁ O ₂ A value of (d); during processing, the tool electrode 1 is driven to swing through the driving assembly, 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.

In which the measurement S is carried out by means of an automatic centering module on the machine tool ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ 2.055mm, 2.060mm, 2.065mm, 2.050mm, respectively, in which case, S ₁ ＝2.058mm。

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

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 the driving assembly.

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

Wherein, in the course of processing, the electrical parameter satisfies:

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

Specifically, the driving assembly comprises a transmission rod 2, one end of the transmission rod 2 is connected with the tool electrode 1, 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 tube 6. Wherein the stainless steel pipe 6 is kept still during the processing.

Wherein, in the course of processing, the non-electric parameter satisfies:

the swing speed of the transmission rod 2 is 0.5rpm, and the machining gap S ₂ 10 μm, a processing speed of 0.04g/min, a single-side feed O ₁ O ₂ Is 2.248mm.

Wherein, two equal-height positioning blocks 3 are arranged, the two equal-height positioning blocks 3 are respectively positioned at two sides of the position to be processed of the stainless steel tube 6, and the distance between the two equal-height positioning blocks 3 is 30mm.

Wherein, be equipped with two auxiliary bearing blocks 4, two equal altitude locating pieces 3 are located between two auxiliary bearing blocks 4 to support, fix a position stainless steel pipe 6's both ends through two auxiliary bearing blocks 4.

Wherein, the upper end faces of the equal-height positioning block 3 and the auxiliary bearing block 4 are flush, the upper end faces of the equal-height positioning block 3 and the auxiliary bearing block 4 are provided with V-shaped grooves, and the stainless steel pipe 6 is placed in the V-shaped grooves 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-groove has an angle of 90 ° and a depth of 10mm.

Before the stainless steel tube 6 is placed on the equal-height positioning blocks 3, firstly, the tool electrode 1 needs to be centered and aligned, then, the stainless steel tube 6 penetrates into the discharge end 101 of the tool electrode 1, finally, the equal-height positioning blocks 3, the auxiliary bearing blocks 4 and the clamping plates 5 are used for clamping the stainless steel tube 6, and the stainless steel tube 6 is aligned through the equal-height positioning blocks 3 and the auxiliary bearing blocks 4.

Example 2

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

step 1: adjusting the position of the tool electrode 1 by using the machine tool, so that the plane of the discharge end 101 of the tool electrode 1 is vertical to the working table surface 9 of the machine tool;

specifically, the working table 9 of the machine tool is a horizontal plane, and the tool electrode 1 is vertically installed on the machine tool and connected with a transmission rod installed on the machine tool.

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: adjusting the center line of the discharge end 101 of the tool electrode 1 to coincide with the central axis of the inner cavity of the stainless steel tube 6 by using a machine tool;

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 numerical values are equal or the error is within +/-0.02 mm, the coincidence of the center of the discharge end 101 of the tool electrode 1 and the central axis of the inner cavity of the stainless steel tube 6 is realized, and if the four numerical values are not coincident, the position of the bearing assembly is continuously adjusted by 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 transmission rod 2 controls the discharge end 101 of the tool electrode 1 to eccentrically move around the central axis of the inner cavity of the stainless steel tube 6; the direction of eccentric movement 8 is shown in fig. 9.

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

S ₁₁ 、S ₁₂ 、S ₁₃ 、S ₁₄ the actual measurement values are 2.055mm, 2.060mm, 2.065mm, 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:

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 bevel 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 circular end of the tool electrode.

It can be seen from table 2 that the average value of the groove depth of the break groove of 10 stainless steel pipes processed by the method is 0.2146mm, the standard deviation is 0.01427, the dispersion coefficient is 0.07, the break groove angles are all 90 degrees, the average value of the wall thickness of the break 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 utility model provides a processingequipment in nonrust steel pipe rupture groove of superfine length which characterized in that: the device comprises a tool electrode arranged on a machine tool, a bearing assembly used for clamping a stainless steel pipe and a driving assembly used for controlling the moving state of the tool electrode;

one end of the tool electrode is a discharge end, the discharge end comprises a plurality of electric spark machining points which are circumferentially arranged around the stainless steel pipe, and the same electric spark machining point comprises a working state and a non-working state;

and the working state of the electric spark machining points which are circumferentially arranged around the stainless steel pipe realizes the machining of the fracture groove on the surface to be machined.

2. The apparatus of claim 1, wherein: the bearing assembly comprises an equal-height positioning block, an auxiliary positioning block and a clamping plate which are arranged on a machine tool;

the clamping plate is connected to the equal-height blocks and used for limiting the stainless steel pipe;

3. The apparatus of claim 2, wherein: the bearing assembly comprises two equal-height positioning blocks and two auxiliary bearing blocks;

wherein the distance between the two equal-height positioning blocks is 20-50mm.

4. The apparatus of claim 2 or 3, wherein: the upper end faces of the equal-height positioning block and the auxiliary bearing block are flush, and V-shaped grooves are formed in the upper end faces of the equal-height positioning block and the auxiliary bearing block and used for placing stainless steel pipes to limit the stainless steel pipes.

5. The apparatus of claim 1, wherein: when the distance between the electric spark machining point location and the surface to be machined is larger than a threshold value, the electric spark machining point location is in a non-working state;

6. The apparatus of claim 1, wherein: and a plurality of electric spark machining point positions which are arranged around the stainless steel pipe in the circumferential direction are continuously distributed around the stainless steel pipe in the circumferential direction.

7. The apparatus of claim 1, wherein: the plurality of electric spark machining point positions arranged around the circumference of the stainless steel pipe form a continuous ring shape, and the inner circle end of the ring is matched with the fracture groove in shape.

8. The apparatus of claim 1, wherein: the annular discharge end of the tool electrode is of a rigid structure and is sleeved on the stainless steel pipe, and during machining, the annular discharge end of the tool electrode moves eccentrically around the central axis of the inner cavity of the stainless steel pipe.

9. The apparatus of claim 8, wherein: the driving assembly comprises a transmission rod, one end of the transmission rod is connected with the tool electrode, and the other end of the transmission rod is arranged on the machine tool during machining so as to drive the transmission rod to swing through the machine tool to drive the discharge end of the tool electrode to move eccentrically around the central axis of the inner cavity of the stainless steel pipe.

10. A method for processing a breaking groove of an ultra-long stainless steel pipe is characterized by comprising the following steps: comprises processing the stainless steel pipe fracture groove by using the processing device of any one of claims 1-9;

wherein, during processing, the non-electric parameters satisfy:

wherein, when processing, the electrical parameter satisfies: