A machining device and method for a V-shaped groove of an ultra-fine long thin-walled pipe

Abstract

The present application relates to a kind of processing device and method of ultra-long thin-walled pipe V-shaped groove, belong to the technical field of ultra-long pipe processing, solve the problem that high-precision processing V-shaped groove on ultra-long thin-walled pipe is difficult to realize in prior art.The processing device includes tool electrode installed on machine tool, universal adjustable clamp for aligning tool electrode, driving assembly for controlling the moving state of tool electrode, and bearing assembly for clamping thin-walled pipe;The tool electrode one end includes a plurality of circumferentially arranged electric spark machining point around thin-walled pipe, and the working state of a plurality of circumferentially arranged electric spark machining point around thin-walled pipe realizes the processing of V-shaped groove on the surface to be processed.High-precision processing of ultra-long thin-walled pipe V-shaped groove is realized, and it can be processed in place at one time, and processing efficiency is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of ultra-slender tube processing technology, and in particular to a processing apparatus and method for V-grooves in ultra-slender thin-walled tubes. Background Technology

[0002] V-grooves need to be machined on some ultra-slender aircraft products. Due to the small diameter and thin wall thickness of these products, the dimensions of the V-grooves need to be even smaller. For aircraft products where dimensional control is crucial, the precision requirements for V-groove machining place higher demands on the machining methods.

[0003] Traditional turning methods are insufficient to meet the machining accuracy requirements of V-grooves. This is because the clamping of the part and the application of cutting forces during turning inevitably affect the machining accuracy of the V-grooves.

[0004] Therefore, in order to meet the processing requirements of V-grooves on ultra-slender aircraft products, it is necessary to explore new V-groove processing devices. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a processing apparatus and method for V-grooves in ultra-slender thin-walled tubes, in order to solve the problem that it is difficult to achieve high-precision processing of V-grooves on ultra-slender thin-walled tubes.

[0006] On one hand, embodiments of the present invention provide a processing device for V-grooves of ultra-thin and long thin-walled tubes, including a tool electrode mounted on a machine tool, a universal adjustable clamp for aligning the tool electrode, a drive assembly for controlling the movement state of the tool electrode, and a bearing assembly for clamping the thin-walled tube.

[0007] One end of the tool electrode includes multiple electrical discharge machining points arranged around the circumference of the thin-walled tube. The working state of the multiple electrical discharge machining points arranged around the circumference of the thin-walled tube realizes the machining of V-grooves on the surface to be machined.

[0008] Based on further improvements to the above-mentioned processing device, the universal adjustable fixture includes a clamping part for clamping the tool electrode, a first adjustment part for aligning the tool electrode on the XY plane of the machine tool, and a second adjustment part for aligning the tool electrode on the YZ plane of the machine tool.

[0009] From bottom to top, the clamping part, the first adjusting part, and the second adjusting part are sequentially connected to each other.

[0010] Based on further improvements to the above-mentioned processing device, the first adjustment part includes a first fixed seat and a second fixed seat distributed on the upper and lower sides. The second fixed seat is installed at the lower end of the first fixed seat by a plurality of vertical screws, and the clamping part is installed at the lower end of the second fixed seat.

[0011] Wherein, the adjacent surfaces of the first fixing seat and the second fixing seat are provided with a gap;

[0012] The tilt angle of the second fixed seat in the XY direction of the machine tool is adjusted by adjusting the position of the vertical screw in the Z-axis direction of the machine tool.

[0013] Based on further improvements to the above-mentioned processing device, the second adjustment unit includes a clamping head mounted on the machine tool, a first connecting body fixedly connected to the clamping head, a rotating body rotatably connected to the first connecting body in the horizontal direction, and a second connecting body fixedly connected to the rotating body; the second connecting body is connected to the first fixed seat.

[0014] The rotating body is equipped with an angle adjustment bolt, which allows the spatial position of the rotating body to be adjusted.

[0015] Based on the further improvement of the above processing device, one end of the angle adjusting bolt is screwed onto the rotating body so as to drive the rotating body to rotate when the angle adjusting bolt is pushed;

[0016] The lower end of the first connecting body has a cavity for placing the rotating body. The rotating body is installed in the cavity. A slot is provided on the side wall of the cavity. The other end of the angle adjusting bolt is slidably installed in the slot.

[0017] Based on further improvements to the aforementioned processing device, when the angle adjustment bolt is pushed to adjust the tilt angle of the tool electrode on the YZ plane of the machine tool, the pushing angle β satisfies:

[0018] Where S is the distance the dial indicator needle moves; v1 is the speed at which the dial indicator moves; and t1 is the time it takes for the dial indicator to move.

[0019] Based on further improvements to the above-mentioned processing device, the drive assembly includes a transmission rod, one end of which is mounted on the clamping part. During processing, the other end of the transmission rod is mounted on the machine tool so as to drive the clamping part to move through the transmission rod, thereby driving the tool electrode to move.

[0020] Based on the further improvement of the above processing device, one end of the tool electrode is a discharge end, and the discharge end includes a plurality of electrical discharge machining points arranged around the circumference of the thin-walled tube. The same electrical discharge machining point includes a working state and a non-working state.

[0021] During processing, multiple electrical discharge machining points arranged around the circumference of the thin-walled tube form a continuous ring, and the inner end of the ring matches the shape of the V-groove.

[0022] Based on further improvements to the above-mentioned processing device, the discharge end of the tool electrode is sleeved on the thin-walled tube, and during processing, the discharge end of the tool electrode makes an eccentric movement around the central axis of the inner cavity of the thin-walled tube.

[0023] On the one hand, embodiments of the present invention also provide a method for processing an ultra-thin, long, thin-walled tube V-groove, including using the above-mentioned processing device to perform electrical discharge machining on the thin-walled tube V-groove.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] 1. This invention adjusts the tilt angle of the tool electrode on the horizontal plane through the first adjustment part of the universal adjustable fixture; based on the detection value of the dial indicator and the time and speed of the dial indicator movement, the tilt angle of the tool electrode on the YZ plane of the machine tool is determined, compared with the angle scale value on the first connecting body, and the rotation adjustment bolt is pushed to the corresponding scale, so as to achieve high-precision adjustment of the tilt angle of the tool electrode on the YZ plane of the machine tool, thereby realizing the alignment of the tool electrode, which is convenient to operate and improves processing efficiency and accuracy.

[0026] 2. During processing, simply place the ultra-thin stainless steel tube in the V-shaped groove on the level positioning block and auxiliary bearing block, and use the clamping plate to limit the upper surface of the ultra-thin stainless steel tube to achieve clamping and positioning of the ultra-thin stainless steel tube. The clamping is convenient and can ensure the stability of the ultra-thin stainless steel tube during the processing.

[0027] 3. The discharge end of the tool electrode of the present invention is annular, which is fitted onto the outer end face of the ultra-thin stainless steel tube and moves eccentrically. During this process, the distance between the end face of the discharge end and the end face of the ultra-thin stainless steel tube to be processed is constantly changing. The closer end is the working end, and the farther end is the non-working end. In this way, the outer end face of the ultra-thin stainless steel tube is subjected to electrical discharge machining through the working end. That is, along the processing direction, the position of the working end on the inner circular end face of the discharge end is constantly changing. When the inner circular end face of the discharge end is close to the outer end face of the ultra-thin stainless steel tube, the end face of the discharge end is the working end. When the end face is far away from the outer end face of the ultra-thin stainless steel tube, the end face becomes the non-working end. This realizes the dynamic transformation between the working end and the non-working end, thereby avoiding the working end of the tool electrode being in a continuous processing state, greatly reducing the wear of the working end of the tool electrode, achieving a tool electrode wear of ≤1%, and further reducing the deformation of the working end face of the tool electrode, thereby improving the accuracy of processing the fracture groove of the ultra-thin stainless steel tube.

[0028] 4. The discharge end of the tool electrode of the present invention is fitted onto an ultra-thin stainless steel tube and moves eccentrically. During processing, the distance between the discharge end and the ultra-thin stainless steel tube decreases and then increases. During the process of decreasing distance, metal debris is generated between the discharge end and the stainless steel tube. At this time, some of the metal debris will be discharged with the working fluid through the processing gap. During the process of increasing distance, the distance between the discharge end and the stainless steel tube can increase by nearly 200 times, which significantly improves the efficiency of metal debris discharge. This avoids the accumulation of metal debris at the discharge end due to untimely discharge, thereby reducing the wear of the tool electrode and avoiding the risk of short circuit caused by the tool electrode directly connecting to the stainless steel tube through metal debris.

[0029] 5. By using the discharge end of the tool electrode to make an eccentric movement on the ultra-thin stainless steel tube, metal chips can be efficiently discharged, thereby enabling electrical discharge machining with a smaller machining gap. This reduces the machining current and voltage, lowers machining costs, and produces fracture grooves with low surface roughness.

[0030] 6. By adjusting the value of the single-sided feed, it is possible to process fracture grooves with different wall thicknesses. By adjusting the shape of the discharge end of the tool electrode, it is possible to process dimensions with different bevel angles α, laying the foundation for rapid production and mass production of products.

[0031] 7. The tool electrode of the present invention can complete the processing of the fracture groove of the ultra-thin stainless steel tube by moving eccentrically around the central axis of the inner cavity of the ultra-thin stainless steel tube for one revolution, achieving one-time processing and significantly improving processing efficiency.

[0032] 8. This invention abandons the traditional turning process for ultra-thin stainless steel tubes. It uses the working end of the tool electrode to discharge and erode the metal on the surface of the ultra-thin stainless steel tube to perform the fracture groove processing. That is, during the processing, the tool electrode does not contact the surface of the ultra-thin stainless steel tube, so it will not cause deformation and overcomes the problem of damage to the ultra-thin stainless steel tube by cutting force.

[0033] 9. This invention utilizes the eccentric movement of the discharge end of the tool electrode around the central axis of the inner cavity of the ultra-thin stainless steel tube to process the fracture groove of the ultra-thin stainless steel tube. That is, during the processing, the ultra-thin stainless steel tube does not need to rotate, and a ring-shaped fracture groove can be processed on its outer surface. This overcomes the problem that the coaxiality of the ultra-thin stainless steel tube deteriorates during rotation, which affects the processing accuracy.

[0034] 10. By eccentrically moving the tool electrode around the central axis of the inner cavity of the stainless steel tube, the single-sided feed amount of each end face at the discharge end can be made the same, ensuring the consistency of the processing depth of the break groove, thereby improving the processing accuracy of the break groove.

[0035] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0036] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0037] Figure 1 This is a schematic diagram of the tool electrode structure of the present invention;

[0038] Figure 2 This is a schematic diagram of the overall structure of the universal adjustable clamp of the present invention;

[0039] Figure 3 This is a cross-sectional schematic diagram of the universal adjustable clamp of the present invention;

[0040] Figure 4 This is a schematic diagram of the mating structure between the adapter adjusting bolt and the first connecting body of the present invention;

[0041] Figure 5 for Figure 1 Schematic diagram of the cross-section at point AA;

[0042] Figure 6 This is a schematic diagram of the structure when the center line of the discharge end of the tool electrode of the present invention coincides with the central axis of the inner cavity of the stainless steel tube;

[0043] Figure 7 This is a schematic diagram of the structure when the center line of the tool electrode of the present invention deviates from the central axis of the inner cavity of the stainless steel tube;

[0044] Figure 8 This is a cross-sectional schematic diagram of the discharge end of the tool electrode of the present invention when it is fitted onto a stainless steel tube.

[0045] Figure 9 This is a schematic diagram of the trajectory of the center point O2 of the discharge end when the discharge end of the tool electrode moves eccentrically around the central axis of the inner cavity of the stainless steel tube in this invention.

[0046] Figure 10 This is a schematic diagram of the motion trajectory of any point O3 on the discharge end of the tool electrode when it moves eccentrically around the central axis of the inner cavity of the stainless steel tube in this invention.

[0047] Figure 11 This is a schematic diagram of the stainless steel pipe breakage groove in this invention;

[0048] Figure 12 This is a schematic diagram of the structure of the load-bearing component and the stainless steel tube of the present invention.

[0049] Figure 13 This is a schematic diagram of the structure of the equal-height positioning block, clamping plate and stainless steel tube in this invention.

[0050] Figure 14 This is a schematic diagram of the auxiliary support block and the stainless steel pipe working together in this invention;

[0051] Figure 15 This is a schematic diagram of the actual product after the stainless steel pipe fracture groove has been processed in this invention.

[0052] Figure label:

[0053] 1-Tool electrode; 101-Discharge end; 102-Working end; 103-Non-working end; 104-Conductive end; 2-Transmission rod; 3-Equal height positioning block; 4-Auxiliary bearing block; 5-Clamping plate; 6-Stainless steel tube; 601-Break groove; 7-Machining direction; 8-Eccentric motion direction; 9-Machine tool worktable; 10-Reference seat; 11-Clamping seat; 12-Fastening screw; 13-First fixed seat; 14-Second fixed seat; 15-Vertical 16-Straight screw; 17-Insulating plate; 18-Clamp head; 19-First connecting body; 20-Second connecting body; 21-Rotating body; 22-Angle adjusting bolt; 23-Slot; 24-Movement direction of dial indicator on the discharge end face of tool electrode along the Z-axis of machine tool; H1-Wall thickness of stainless steel pipe; H2-Wall thickness of fracture groove; α-Angle of fracture groove; S 11 S 12 S 13 S 14 - Actual clearance values ​​between four points selected on the circular working end of the tool electrode and the outer end face of the stainless steel tube; S2 - Machining clearance; O1 - Center point of the discharge end; O2 - Center point of the inner cavity of the stainless steel tube; O3 - Point selected on the discharge end; S - Distance of movement of the dial indicator needle; v1*t1 - Distance of movement of the dial indicator. Detailed Implementation

[0054] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0055] A diameter-to-length ratio of 1:100–150 generally qualifies as an ultra-slender shaft. For example, a stainless steel tube used in a certain aircraft product has an outer diameter of 2mm, an inner diameter of 1mm, and a length of 1–1.2m. This stainless steel tube has an outer diameter-to-length ratio of 1:500–600, classifying it as an ultra-slender stainless steel tube. During processing, a V-groove is typically machined into the ultra-slender steel tube. This V-groove serves as a breakaway groove, used to separate the aircraft product's guidance system from the fairing when the product reaches a predetermined altitude and position.

[0056] Because ultra-thin stainless steel tubes have small diameters and thin walls, and the wall thickness at the break groove location is even thinner (e.g., 0.3±0.05mm), it is impossible to determine their critical dimensions through direct measurement. When machining a break groove at a certain location on an ultra-thin stainless steel tube, it is difficult to guarantee the wall thickness at the break groove location using traditional turning methods. This is because the excessive length will result in a greater centrifugal force during the rotation of the workpiece, leading to poorer coaxiality of the workpiece, and the resulting cutting force can easily cause deformation of the ultra-thin stainless steel tube.

[0057] To solve the above problems, the present invention provides a processing device for V-grooves of ultra-thin and long thin-walled tubes, including a tool electrode 1 mounted on a machine tool, a universal adjustable clamp for aligning the tool electrode 1, a drive assembly for controlling the movement state of the tool electrode 1, and a bearing assembly for clamping the thin-walled tube.

[0058] The tool electrode 1 includes multiple electrical discharge machining points arranged around the circumference of the thin-walled tube. The working state of the multiple electrical discharge machining points arranged around the circumference of the thin-walled tube realizes the machining of V-grooves on the surface to be machined.

[0059] Specifically, one end of the tool electrode 1 is a discharge end 101, which includes multiple electrical discharge machining points arranged around the thin-walled tube in the circumferential direction. The same electrical discharge machining point includes a working state and a non-working state.

[0060] When the distance between the EDM point and the surface to be processed is greater than the threshold, the EDM point is in a non-working state.

[0061] When the distance between the EDM point and the surface to be processed is less than or equal to the threshold, the EDM point is in working state.

[0062] The above threshold is the discharge distance between the EDM point that meets the processing requirements and the surface to be processed. For example, this distance is 0-50μm.

[0063] It is understandable that the discharge end 101 includes multiple electrical discharge machining points arranged around the circumference of the thin-walled tube. These multiple electrical discharge machining points can be continuously and uninterruptedly distributed around the circumference of the thin-walled tube, or they can be discontinuously distributed around the circumference of the thin-walled tube, as long as they can achieve continuous machining and forming of V-shaped grooves on the surface to be machined.

[0064] In one possible implementation, such as Figure 1 As shown, one end of the tool electrode 1 is annular, meaning that multiple electrical discharge machining points arranged around the circumference of the thin-walled tube form a continuous annular shape, such as... Figure 5-8 As shown, the inner circle of the ring matches the shape of the V-groove, that is, the inner circle is convex and the V-groove is concave. The cross-sectional dimensions of the convex shape are the same as the cross-sectional shape of the concave shape. The other end of the tool electrode 1 is a conductive end 104, which is electrically connected to an output end of a power supply device installed on the machine tool to introduce current and transmit the current to the inner circle. At this time, the inner circle is a discharge end 101, so that the V-groove on the surface to be processed can be realized through the working state of multiple electrical discharge machining points arranged around the thin-walled tube through the discharge end 101.

[0065] In one possible implementation, the discharge end is a rigid structure, with the discharge end 101 fitted onto the outer end face of the stainless steel tube 6. During processing, the stainless steel tube 6 is electrically connected to another output end of the power supply device, and the tool electrode 1 moves eccentrically around the central axis of the inner cavity of the stainless steel tube 6. During the eccentric movement of the tool electrode 1, the distance between the inner circular end face of the discharge end 101 and the end face of the stainless steel tube 6 to be processed continuously changes. When the distance between the electrical discharge machining point and the surface to be processed is greater than a threshold, the electrical discharge machining point is in a non-working state; at this time, the electrical discharge machining point is the non-working end 103. When the distance between the electrical discharge machining point and the surface to be processed is less than or equal to a threshold, the electrical discharge machining point is in a non-working state. When the threshold is reached, the electrical discharge machining (EDM) point is in the working state. At this time, the EDM point is the working end 102. In this way, the transition between the working state and the non-working state is realized at the same EDM point. The working states of all EDM points together realize the machining of the fracture groove on the surface to be machined. That is to say, the position of the working end 102 is constantly changing within the inner circular end face of the discharge end 101. The circular discharge end of the tool electrode moves eccentrically around the central axis of the inner cavity of the stainless steel tube. All the working ends form a continuous circular discharge end around the circumference of the stainless steel tube. In this way, the discharge end 101 of the tool electrode 1 is avoided from being in a continuous machining state, thereby reducing the wear of the tool electrode 1.

[0066] During the eccentric movement of the tool electrode 1, the distance between the end face of the discharge end 101 and the end face to be processed of the stainless steel tube 6 continuously changes. A distance of 10-50 μm indicates the working state, i.e., the working end 102, while a distance greater than 50 μm indicates the non-working state, i.e., the non-working end 103. The processing trajectories of all working ends 102 together constitute the ultra-slender stainless steel tube breakage groove 601.

[0067] Among them, the annular discharge end 101 of the tool electrode 1 includes several working ends 102 distributed in a ring. When the discharge end moves eccentrically around the central axis of the inner cavity of the stainless steel tube 6 for processing, the several working ends 102 are in a non-synchronous and non-continuous processing state; and the processing trajectory of the several working ends together constitutes the break groove of the stainless steel tube 6.

[0068] In this process, after the tool electrode 1 completes one eccentric movement, all end faces of the discharge end 101 participate in electrical discharge machining. That is, all working ends 102 constitute a complete discharge end 101, and the machining trajectories of all working ends 102 together form the ultra-slender stainless steel tube breakage groove 601. Along the machining direction 7, the working ends 102 exhibit a "circular motion" phenomenon on the discharge end 101. That is, the position of the working ends 102 is different at different times. In this way, all working ends 102 are processed alternately and in an orderly manner. The machining direction 7 is the circumferential direction around the outer end face of the stainless steel tube 6, and the plane containing this circumferential direction is perpendicular to the central axis of the inner cavity of the stainless steel tube 6.

[0069] Compared with the prior art, the present invention utilizes a universal adjustable fixture to conveniently align the tool electrode and uses a bearing component to align the thin-walled tube, thereby aligning the central axis of the inner cavity of the thin-walled tube with the center line of the discharge end of the tool electrode, so as to determine the value of the single-sided feed. At the same time, by using the eccentric movement of the discharge end of the tool electrode around the central axis of the inner cavity of the thin-walled tube, the single-sided feed value of multiple EDM points is made equal, thereby improving the machining accuracy of the V-groove. Furthermore, the discharge end 101 of the tool electrode 1 is annular, and it moves eccentrically around the outer end face of the stainless steel tube 6. During this process, the distance between the end face of the discharge end 101 and the end face of the stainless steel tube 6 to be processed is constantly changing. The closer end is the working end 102, and the farther end is the non-working end 103. The outer end face of the stainless steel tube 6 is subjected to electrical discharge machining through the working end 102. Along the machining direction, the position of the working end 102 is constantly changing within the inner circular end face of the discharge end 101, that is, the inner circular end face of the discharge end 101 is close to the stainless steel tube 6. When the discharge end 101 is on the outer end face of the 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 stainless steel tube 6, the end face changes to the non-working end 103, realizing the dynamic transformation between the working end 102 and the non-working end 103. In this way, the working end 102 of the tool electrode 1 is not in a continuous processing state, which greatly reduces the wear on the working end of the tool electrode 1, achieving a tool electrode wear of ≤1%, thereby reducing the deformation of the working end face of the tool electrode 1, and thus improving the processing accuracy of the ultra-thin stainless steel tube break groove 601.

[0070] Specifically, one end of the tool electrode 1 is mounted on a machine tool, and the discharge end 101 of the tool electrode 1 is fitted onto the outer end face of the stainless steel tube 6. The center of the inner circle 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 there is a clearance between the discharge end 101 and the outer end face of the stainless steel tube 6. That is, the diameter of the inner circle of the discharge end 101 is larger than the outer diameter of the stainless steel tube 6. For example, the diameter of the inner circle is 10-20 mm, which is 5-10 times the outer diameter of the stainless steel tube 6. This facilitates the determination of the single-sided feed rate O1O2 during the electrical discharge machining process. During machining, the tool electrode 1 is oscillated by the machine tool. At this time, 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 tube 6.

[0071] Among them, the unilateral feed rate O1O2 satisfies:

[0072] O1O2=S1+(H1-H2)-S2

[0073] Where O1 represents the center point of the discharge terminal 101 of the tool electrode;

[0074] O2 indicates the center point of the inner cavity of the stainless steel pipe 6;

[0075] H1 is the wall thickness of stainless steel pipe 6;

[0076] H2 is the wall thickness of the fracture groove 601;

[0077] S2 is the machining clearance, which refers to the closest distance between the working end 102 and the end face of the stainless steel tube 601 when the tool electrode 1 moves eccentrically.

[0078] S1 indicates that there is a margin gap between the discharge end 101 and the outer end face of the stainless steel tube 6.

[0079] Wherein, S1 satisfies:

[0080]

[0081] Among them, such as Figure 6 As shown, S 11 S 12 S 13 S 14 The actual clearance value between four points selected on the discharge end 101 of the tool electrode and the outer end face of the stainless steel tube 6 is given. These four points are evenly distributed on the discharge end 101.

[0082] For example, S 11 S 12 S 13 S 14 The corresponding values ​​are 2.055mm, 2.060mm, 2.065mm, and 2.050mm, respectively. At this time, S1 = 2.058mm.

[0083] The machining gap S2 is set to 10-50 μm to meet the requirements of electrical discharge machining.

[0084] For example, S2 = 10 μm; H1 = 0.5 mm, H2 = 0.3 mm, S1 = 2.058 mm, and O1O2 = 2.248 mm.

[0085] Among them, the automatic centering module on the machine tool can be used to measure S. 11 S 12 S 13 S 14 If the four values ​​are equal, the center of the inner circle 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.

[0086] Among them, after the center of the discharge end 101 of the machine tool adjustment tool electrode 1 is aligned with the central axis of the inner cavity of the stainless steel tube 6, the actual measured S 11 S 12 S 13 S 14The closer the four values ​​are, the more accurate the value of S1 will be, and the more accurate the single-sided feed amount O1O2 will be. In this way, the accuracy of the machining gap can be ensured during the eccentric movement of the tool electrode 1, thereby ensuring the machining depth of the working end 101 and ensuring the dimensional accuracy of the machined break groove 601.

[0087] In this process, after the center of the discharge end 101 of the adjustment tool electrode 1 coincides 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 machine tool. The detailed process is as follows.

[0088] The movement trajectories of the center point O1 of the discharge terminal 101 of the tool electrode 1 and the center point O2 of the inner cavity of the stainless steel tube 6 are described below:

[0089] Move tool electrode 1 so that O1 is away from O2. The moving distance is the same as the unilateral feed amount O1O2. At this time, the distance between O1 and O2 is O1O2.

[0090] With O2 as the center and O1O2 as the radius, rotate O1 around O2. The trajectory of O1's movement will then be a circle, as shown below. Figure 9 As shown, the center of the circle is O2, and the radius is O1O2;

[0091] During the movement of O1, when the closest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10μm, the power supply device is turned on to deliver a pulse voltage to the tool electrode 1 and the stainless steel tube 6, and the metal on the surface of the stainless steel tube 6 is etched at a processing speed of 0.04g / min until the distance between O1 and O2 is O1O2, and then O1 moves in a circular motion around O2.

[0092] To further illustrate the motion trajectory of tool electrode 1, an arbitrary point O3 on discharge terminal 101 is selected, and the trajectory of O3 is used for illustration, as follows:

[0093] Move tool electrode 1 so that O3 moves toward O2, and the moving distance is O1O2;

[0094] As O1 rotates around O2, at this time, as... Figure 10 As shown, the trajectory of O3 is a circle with the initial position of O3 as the center and O1O2 as the radius;

[0095] During the movement of O3, when the closest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10μm, the power supply device is turned on to deliver a pulse voltage to the tool electrode 1 and the stainless steel tube 6, and the metal on the surface of the stainless steel tube 6 is etched at a processing speed of 0.04g / min until the moving distance of O3 reaches O1O2. Then, O3 moves in a circle with its initial position as the center.

[0096] Thus, during the eccentric movement of the tool electrode 1, the distance between the inner circular end face of the discharge end 101 and the outer surface of the stainless steel tube 6 changes continuously. The distance between each part of the inner circular end face of the discharge end 101 and the outer end face of the stainless steel tube 6 changes from close to far away. Consequently, the discharge end 101 changes from a working state to a non-working state, that is, the dynamic transformation between the working end 102 and the non-working end 103 is realized. In this way, the working end 102 of the tool electrode 1 is avoided from being in a continuous processing state, which greatly reduces the wear on the working end 102 of the tool electrode 1.

[0097] The discharge end 101 has a clearance S1 between itself and the outer end face of the stainless steel tube 601. This clearance ensures that the non-working end 103 at the discharge end 101 and the end face of the stainless steel tube 6 have a sufficiently large non-processing clearance, thereby 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, when the tool electrode 1 moves eccentrically, the working end 102 and the non-working end 103 can be dynamically switched.

[0098] The conductive end of the tool electrode 1 is electrically connected to one output end of the power supply device installed on the machine tool, and the stainless steel tube 6 is electrically connected to the other output end of the power supply device. The power supply device includes a pulse power supply, and its two output ends are respectively connected to the positive and negative terminals of the pulse power supply to output pulse voltage.

[0099] For example, during the processing, the electrical parameters satisfy:

[0100] Pulse width 30–60 μs, pulse interval 20–30 μs, average machining current 0.8–2 A, average machining voltage 30–60 V.

[0101] Specifically, the aforementioned drive assembly includes a transmission rod 2. One end of the transmission rod 2 is connected to the tool electrode 1 via a universal adjustable clamp, and the other end of the transmission rod 2 is mounted on a machine tool. The machine tool can control the swing of the transmission rod 2, thereby driving the discharge end 101 of the tool electrode 1 to make an eccentric movement around the central axis of the inner cavity of the stainless steel tube 6.

[0102] Specifically, the transmission rod 2 swings clockwise within the swing plane YZ, which is parallel to the plane containing the discharge end 101. This achieves the eccentric movement of the discharge end of the tool electrode 1 around the central axis of the inner cavity of the stainless steel tube 6. During processing, the stainless steel tube 6 remains stationary.

[0103] For example, during the processing, the non-electrical parameters satisfy:

[0104] The oscillation speed of the drive component is 0.4 to 0.6 rpm, the machining gap is 10 to 50 μm, the machining speed is 0.02 to 0.045 g / min, and the single-sided feed rate is 2.214 to 2.2316 mm.

[0105] The plane containing the trajectory of movement in both the X and Y axes of the machine tool is called the XY plane, which is the horizontal plane; the plane containing the trajectory of movement in both the Y and Z axes of the machine tool is called the YZ plane.

[0106] Specifically, the universal adjustable fixture is connected to the tool electrode 1 and is used to adjust the control position of the tool electrode 1 to achieve alignment of the tool electrode and ensure machining accuracy.

[0107] Among them, such as Figure 2-4 As shown, the universal adjustable fixture includes a clamping part for clamping the tool electrode 1, a first adjustment part for aligning the tool electrode 1 in the XY plane of the machine tool, and a second adjustment part for aligning the tool electrode 1 in the YZ plane of the machine tool. The clamping part, the first adjustment part, and the second adjustment part are sequentially connected to each other from bottom to top. During alignment, the first adjustment part is first used to align the tool electrode 1 in the XY plane of the machine tool, and then the second adjustment part is used to align the tool electrode 1 in the YZ plane of the machine tool to ensure that the discharge end face of the tool electrode 1 is perpendicular to the position to be processed of the stainless steel tube.

[0108] Specifically, the clamping part includes a reference base 10 and a clamping seat 11 mounted on the reference base 10. The space between the adjacent surfaces of the clamping seat 11 and the reference base 10 is a clamping space for mounting the tool electrode 1. During installation, the upper end of the tool electrode 1 is mounted in the clamping space to achieve clamping of the tool electrode 1.

[0109] Furthermore, the aforementioned clamping part also includes a fastening screw 12 for adjusting the clamping force on the tool electrode 1. The fastening screw 12 is screwed onto the clamping seat 11, with one end passing through the clamping seat 11 and located within the clamping space. During installation, after placing the upper end of the tool electrode 1 within the clamping space, the fastening screw 12 is rotated to press against the end face of the tool electrode 1, thereby clamping the tool electrode 1 and preventing it from slipping.

[0110] The inner end face of the clamping space that connects with the tool electrode 1 is a V-shaped surface, and the upper end face of the tool electrode 1 is adapted to this V-shaped surface. The angle of the V-shaped surface is 90° to prevent the tool electrode 1 from sliding in the horizontal direction during the clamping process of the fastening screw 12. This achieves the clamping of the tool electrode 1.

[0111] Specifically, the first adjustment part includes a first fixing seat 13 and a second fixing seat 14 distributed vertically. The second fixing seat 14 is installed at the lower end of the first fixing seat 13 by a vertical screw 15, and there is a gap between the adjacent surfaces of the first fixing seat 13 and the second fixing seat 14. One end of the vertical screw 15 passes through the first fixing seat 13 and the second fixing seat 14 and is screwed to the first fixing seat 13 and slidably connected to the second fixing seat 14. A nut is provided at the bottom of the vertical screw 15 to limit the second fixing seat 14 in a direction perpendicular to the second fixing seat 14 so that the tilt angle of the second fixing seat 14 in the horizontal direction can be adjusted by rotating the vertical screw 15.

[0112] The system includes four vertical screws 15, evenly distributed vertically on the first fixing base 13. Rotating any one of these screws allows for localized adjustment of the horizontal tilt angle of the second fixing base 14. Each screw 15 has a rotating head at its top, facilitating the application of force to rotate it. Initially, all screw heads have the same clearance with the upper surface of the first fixing base to ensure sufficient screw-in space.

[0113] For example, if the vertical screw 15 located at the left end of the first fixing seat 13 is rotated clockwise, the vertical screw 15 will cause the left end of the second fixing seat 14 to tilt downward.

[0114] Furthermore, an insulating plate 16 is fixedly installed at the lower end of the second fixed base 14. The reference base 10 is fixedly connected to the lower end face of the insulating plate 16. Thus, when adjusting the tilt angle of the second fixed base 14 in the horizontal direction, the tool electrode 1 can be aligned in the vertical direction. At the same time, the insulating plate 16 can prevent the operator from being electrocuted.

[0115] For example, when the left end of the second fixing seat 14 tilts downward, the lower end of the tool electrode 1 tilts to the right.

[0116] Specifically, the second adjustment unit includes a clamp head 17, a first connecting body 18, a second connecting body 19, and a rotating body 20. The clamp head 17 is mounted on the machine tool, the first connecting body 18 is fixedly connected to the clamp head 17, and the rotating body 20 is located between the first connecting body 18 and the second connecting body 19. The upper end of the rotating body 20 is rotatably connected to the first connecting body 18 in the horizontal direction, and the lower end of the rotating body 20 is fixedly connected to the second connecting body 19. The lower end of the second connecting body 19 is fixedly connected to the top of the first fixed seat 13. Thus, by rotating the rotating body 20 in the horizontal direction, the rotation of the second connecting body 19 in the horizontal plane is controlled, thereby adjusting the position of the first fixed seat 13 in the horizontal direction, and thus aligning the tool electrode 1 in the YZ direction of the machine tool.

[0117] The first connecting body 18 has a cavity at its lower end for placing the rotating body 20, which is placed inside the cavity. The upper end of the rotating body 20 is rotatably mounted on the top wall of the cavity. An angle adjusting bolt 21 is installed at one end of the rotating body 20. One end of the angle adjusting bolt 21 is screwed onto the rotating body 20, and the other end passes through the cavity wall of the first connecting body 18 and is located outside the first connecting body 18. A slot 22 is provided on the side end face of the first connecting body 18 so that the angle adjusting bolt 21 can slide in the slot 22 when the rotating body 20 rotates. The end of the angle adjusting bolt 21 located outside the first connecting body 18 is a bolt head. By rotating the bolt head, the angle adjusting bolt 21 can be moved closer to or away from the first connecting body, thereby adjusting the clamping force of the angle adjusting bolt 21 on the first connecting body 18 and thus adjusting the state of the rotating body 20.

[0118] For example, the angle adjusting bolt 21 is rotated counterclockwise until the clamping force of the angle adjusting bolt 21 on the first connecting body 18 is eliminated. At this time, the rotating body 20 can rotate freely, and the rotation angle is limited by the length of the slot 22.

[0119] For example, the angle adjusting bolt 21 is rotated clockwise until it is pressed against the end face of the first connecting body 18. At this time, the rotating body 20 cannot rotate.

[0120] Furthermore, an angle value scale surface, i.e. a scale surface for rotation angle, is provided along the length direction of the slot 22. The angle adjustment bolt 21 is located at the middle of the slot 22 as 0°. When rotating clockwise, the maximum position of the angle adjustment bolt 21 is 10° to 30°. When rotating counterclockwise, the maximum position of the angle adjustment bolt 21 is -30° to -10°. In this way, the rotation angle of the rotating body 20 can be precisely adjusted, thereby achieving precise adjustment of the tool electrode 1.

[0121] Among them, the surface with a scale on the end face of the first connector 18 is used as a reference surface to push the angle adjusting bolt 21 to rotate, and the pushing angle is β;

[0122] Among them, with the center of the rotating body 20 as the center, the angle β pushed by the angle adjusting bolt 21 satisfies:

[0123]

[0124] Wherein, S: with the discharge end face of tool electrode 1 as the reference plane, the dial indicator is moved in the Y-axis direction of the machine tool, and the distance the dial indicator needle moves is S;

[0125] v1 is the speed at which the dial indicator moves;

[0126] t1 is the time it takes for the dial indicator to move.

[0127] During the alignment of tool electrode 1, a dial indicator is used to align the reference surface of tool electrode 1, and the universal adjustable fixture is adjusted to ensure that the relative positional error between the tool electrode and the machine tool's XYZ axes is ≤0.01mm.

[0128] Specifically, one end of the transmission rod 2 is fixedly connected to the reference base 10, and the transmission rod 2 is parallel to the center line of the discharge end 101 of the tool electrode 1. During the processing, the other end of the transmission rod 2 is mounted on the machine tool, so that the machine tool drives the transmission rod 2 to swing, and then drives the tool electrode 1 and the universal adjustable fixture to move, so as to realize that the discharge end 101 of the tool electrode 1 makes an eccentric movement around the central axis of the inner cavity of the stainless steel tube 6.

[0129] Specifically, such as Figure 11-14 As shown, the bearing assembly includes a height positioning block 3 and an auxiliary bearing block 4 mounted on the machine tool; the stainless steel pipe 6 is placed on the height positioning block 3 and the auxiliary bearing block 4 to clamp the stainless steel pipe 6.

[0130] Specifically, two equal-height positioning blocks 3 are provided, which are located on both sides of the position to be processed of the stainless steel tube 6, to ensure the stability of the position to be processed during the processing. For example, the distance between the two equal-height positioning blocks 3 is 20-50mm.

[0131] Specifically, two auxiliary support blocks 4 are provided, and two equal-height positioning blocks 3 are located between the two auxiliary support blocks 4, so as to support and position the two ends of the stainless steel pipe 6 through the two auxiliary support blocks 4, and further ensure the stability of the stainless steel pipe 6 during the processing.

[0132] The upper surfaces of the equal-height positioning block 3 and the auxiliary bearing block 4 are flush, and a V-shaped groove is provided on the upper surfaces of the equal-height positioning block 3 and the auxiliary bearing block 4. The stainless steel pipe 6 is placed in the V-shaped groove to limit the movement of the stainless steel pipe 6.

[0133] Furthermore, a clamping plate 5 is provided on the leveling positioning block 3. The clamping plate 5 covers the V-groove and is engaged with the leveling positioning block 3 to limit the movement of the stainless steel tube 6 and further improve the stability of the stainless steel tube 6. For example, the angle of the V-groove is 60°-90° and the depth is 5-10mm.

[0134] Before placing the stainless steel tube 6 on the leveling block 3, the tool electrode 1 needs to be aligned using a machine tool. Then, the stainless steel tube 6 is inserted into the discharge end 101 of the tool electrode 1. Finally, the stainless steel tube 6 is clamped using the leveling block 3, the auxiliary bearing block 4, and the clamping plate 5, and the leveling block 3 and the auxiliary bearing block 4 are used to align the stainless steel tube 6.

[0135] Specifically, after the tool electrode 1 is aligned, the position of the equal height positioning block 3 and the auxiliary bearing block 4 on the machine tool is adjusted using the XYZ axis of the machine tool to align the stainless steel tube 6, ensuring that the central axis of the inner cavity of the stainless steel tube 6 coincides with the center line of the discharge end 101 of the tool electrode 1, so as to determine the value of the single-sided feed amount and thus improve the machining accuracy.

[0136] The alignment process for stainless steel pipe 6 is as follows.

[0137] First, fix two equal-height positioning blocks 3 and two auxiliary support blocks 4 on the machine tool's worktable 9. Then, use a dial indicator to align the sides of the blocks with the X-axis of the machine tool, ensuring a parallelism error of ≤0.01mm.

[0138] Before placing the stainless steel tube 6 on the leveling block 3, first insert the stainless steel tube 6 into the discharge end 101 of the tool electrode 1, and then place the stainless steel tube 6 on the leveling block 3 and the auxiliary support block 4. In this way, the leveling block 3 and the auxiliary support block 4 are used to align the stainless steel tube 6.

[0139] In addition, the present invention also provides a method for processing V-grooves in ultra-slender thin-walled tubes, including the following steps:

[0140] Step 1: Align the tool electrode using a universal adjustable clamp;

[0141] Step 2: Clamp the thin-walled tube using the bearing assembly and align the thin-walled tube;

[0142] Step 3: The V-groove on the surface to be machined is achieved by utilizing the working state of multiple electrical discharge machining points arranged around the circumference of the thin-walled tube using the tool electrode;

[0143] Specifically, by changing the distance between the EDM point and the surface to be processed, the same EDM point can be in a working state or a non-working state.

[0144] Specifically, one end of the tool electrode 1 is a discharge end 101, which includes a plurality of electrical discharge machining (EDM) points arranged circumferentially around the thin-walled tube. When the distance between the EDM point and the surface to be machined is greater than a threshold, the EDM point is in a non-working state; when the distance between the EDM point and the surface to be machined is less than or equal to the threshold, the EDM point is in a working state. The threshold is the discharge distance between the EDM point and the surface to be machined that meets the machining requirements.

[0145] In this process, the annular discharge end 101 is fitted onto the outer end face of the stainless steel tube 6 and moves eccentrically around the central axis of the inner cavity of the stainless steel tube. During processing, the conductive end 104 at the other end of the tool electrode 1 is electrically connected to the output end of the power supply device to introduce a pulse voltage, thereby realizing the electrical discharge machining of the broken groove of the stainless steel tube.

[0146] During processing, the stainless steel tube 6 is electrically connected to another output end of the power supply device. During the eccentric movement of the tool electrode 1, the distance between the inner circular end face of the discharge end 101 and the end face to be processed of the stainless steel tube 6 is constantly changing. When the distance between the EDM point and the surface to be processed is greater than the threshold, the EDM point is in a non-working state, and at this time, the EDM point is a non-working end 103. When the distance between the EDM point and the surface to be processed is less than or equal to the threshold, the EDM point is in a working state, and at this time, the EDM point is a working end 102. In this way, the working state and non-working state are changed at the same EDM point, and the working states of all EDM points together realize the processing of the break groove on the surface to be processed.

[0147] In other words, the position of the working end 102 changes continuously within the inner circular end face of the discharge end 101. The circular discharge end of the tool electrode moves eccentrically around the central axis of the inner cavity of the stainless steel tube. All the working ends form a continuous annular discharge end around the circumference of the stainless steel tube. This avoids the discharge end 101 of the tool electrode 1 being in a continuous processing state, thereby reducing the wear and tear on the tool electrode 1.

[0148] Among them, the annular discharge end 101 of the tool electrode 1 includes several working ends 102 distributed in a ring. When the discharge end moves eccentrically around the central axis of the inner cavity of the stainless steel tube 6 for processing, the several working ends 102 are in a non-synchronous and non-continuous processing state; and the processing trajectory of the several working ends together constitutes the break groove of the stainless steel tube 6.

[0149] In this process, after the tool electrode 1 completes one eccentric movement, all end faces of the discharge end 101 participate in electrical discharge machining. That is, all working ends 102 constitute a complete discharge end 101, and the machining trajectories of all working ends 102 together form the ultra-slender stainless steel tube breakage groove 601. Along the machining direction 7, the working ends 102 exhibit a "circular motion" phenomenon on the discharge end 101. That is, the position of the working ends 102 is different at different times. In this way, all working ends 102 are processed alternately and in an orderly manner. The machining direction 7 is the circumferential direction around the outer end face of the stainless steel tube 6, and the plane containing this circumferential direction is perpendicular to the central axis of the inner cavity of the stainless steel tube 6.

[0150] 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 50μm. If not, the discharge end 101 is the working end 102; if so, the discharge end 101 is the non-working end 103.

[0151] Specifically, step 1 above includes the following steps:

[0152] S11: The tool electrode 1 is clamped using the clamping part of the universal adjustable clamp, and the tool electrode 1 is pressed tightly using the fastening screw 12;

[0153] S12: Adjust the upper and lower spatial positions of the vertical screw 15 in the XY plane of the machine tool to adjust the tilt angle of the second fixed seat 14 in the horizontal direction.

[0154] S13: Adjust the position of the rotating body 20 on the horizontal plane in the YZ plane of the machine tool to adjust the tilt angle of the tool electrode 1 on the YZ plane of the machine tool.

[0155] In step S11, after placing the upper end of the tool electrode 1 in the clamping space, the fastening screw 12 is rotated to press the end face of the tool electrode 1, thereby pressing the tool electrode 1 and preventing it from sliding.

[0156] Furthermore, the V-shaped inner end face of the clamping space is used to limit the tool electrode 1, so as to prevent the tool electrode 1 from sliding in the horizontal direction during the process of the fastening screw 12 pressing the tool electrode 1.

[0157] Specifically, in S12, the tilt angle of the tool electrode 1 in the horizontal direction is adjusted by using the first adjustment part of the universal adjustable clamp.

[0158] Rotating any vertical screw 15 allows for local adjustment of the tilt angle of the second fixing seat 14 in the horizontal direction.

[0159] For example, rotating the vertical screw 15 located at the left end of the first fixing seat 13 clockwise causes the vertical screw 15 to drive the left end of the second fixing seat 14 to tilt downward, thereby causing the lower end of the tool electrode 1 to tilt to the right through the transmission of the insulating plate.

[0160] Specifically, in S13, the tilt angle of the tool electrode 1 in the YZ direction of the machine tool is adjusted by using the second adjustment part of the universal adjustable fixture.

[0161] The rotating body 20 rotates in the horizontal direction, thereby controlling the second connecting body 19 to rotate in the horizontal plane, and thus adjusting the position of the first fixed seat 13 in the horizontal direction, thereby aligning the tool electrode 1 in the YZ direction of the machine tool.

[0162] By rotating the bolt head, the angle adjusting bolt 21 can be moved closer to or further away from the first connecting body, thereby adjusting the clamping force of the angle adjusting bolt 21 on the first connecting body 18, and thus adjusting the state of the rotating body 20.

[0163] For example, the angle adjusting bolt 21 is rotated counterclockwise until the clamping force of the angle adjusting bolt 21 on the first connecting body 18 is eliminated. At this time, the rotating body 20 can rotate freely, and the rotation angle is limited by the length of the slot 22.

[0164] For example, the angle adjusting bolt 21 is rotated clockwise until it is pressed against the end face of the first connecting body 18. At this time, the rotating body 20 cannot rotate.

[0165] Among them, the surface with a scale on the end face of the first connector 18 is used as a reference surface to push the angle adjusting bolt 21 to rotate, and the pushing angle is β;

[0166] Among them, with the center of the rotating body 20 as the center, the angle β pushed by the angle adjusting bolt 21 satisfies:

[0167]

[0168] Wherein, S: with the discharge end face of tool electrode 1 as the reference plane, the dial indicator is moved in the Y-axis direction of the machine tool, and the distance the dial indicator needle moves is S;

[0169] v1 is the speed at which the dial indicator moves;

[0170] t1 is the time it takes for the dial indicator to move.

[0171] During the alignment of tool electrode 1, a dial indicator is used to align the reference surface of tool electrode 1, and the universal adjustable fixture is adjusted to ensure that the relative positional error between the tool electrode and the machine tool's XYZ axes is ≤0.01mm.

[0172] Specifically, in step 2, the stainless steel pipe 6 is placed on the level positioning block 3 and the auxiliary bearing block 4 to clamp the stainless steel pipe 6.

[0173] Two equal-height positioning blocks 3 are used to clamp the stainless steel tube 6 on both sides of the position to be processed, so as to ensure the stability of the position of the stainless steel tube 6 during processing. For example, the distance between the two equal-height positioning blocks 3 is 20-50mm.

[0174] Two equal-height positioning blocks 3 are placed between two auxiliary bearing blocks 4 to support and position the two ends of the stainless steel pipe 6, thereby further ensuring the stability of the stainless steel pipe 6 during processing.

[0175] The stainless steel pipe 6 is placed in the V-shaped groove opened on the upper end face of the equal height positioning block 3 and the auxiliary bearing block 4 to limit the movement of the stainless steel pipe 6.

[0176] Furthermore, the clamping plate 5 is placed over the V-groove and engaged with the leveling block 3 to limit the movement of the stainless steel tube 6, thereby further improving the stability of the stainless steel tube 6. For example, the angle of the V-groove is 60°-90° and the depth is 5-10mm.

[0177] Before placing the stainless steel tube 6 on the leveling block 3, the tool electrode 1 needs to be aligned using a machine tool. Then, the stainless steel tube 6 is inserted into the discharge end 101 of the tool electrode 1. Finally, the stainless steel tube 6 is clamped using the leveling block 3, the auxiliary bearing block 4, and the clamping plate 5, and the leveling block 3 and the auxiliary bearing block 4 are used to align the stainless steel tube 6.

[0178] Specifically, after the tool electrode 1 is aligned, the position of the equal height positioning block 3 and the auxiliary bearing block 4 on the machine tool is adjusted using the XYZ axis of the machine tool to align the stainless steel tube 6, ensuring that the central axis of the inner cavity of the stainless steel tube 6 coincides with the center line of the discharge end 101 of the tool electrode 1, so as to determine the value of the single-sided feed amount and thus improve the machining accuracy.

[0179] The alignment process for stainless steel pipe 6 is as follows.

[0180] First, fix two equal-height positioning blocks 3 and two auxiliary support blocks 4 on the machine tool's worktable 9. Then, use a dial indicator to align the sides of the blocks with the X-axis of the machine tool, ensuring a parallelism error of ≤0.01mm.

[0181] Before placing the stainless steel tube 6 on the leveling block 3, first insert the stainless steel tube 6 into the discharge end 101 of the tool electrode 1, and then place the stainless steel tube 6 on the leveling block 3 and the auxiliary support block 4. In this way, the leveling block 3 and the auxiliary support block 4 are used to align the stainless steel tube 6.

[0182] 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 to the drive assembly. The drive assembly includes a transmission rod 2, one end of which is connected to the reference seat 10 and is parallel to the center line of the discharge end 101 of the tool electrode 1. During the processing, the other end of the transmission rod 2 is mounted on the machine tool, so that the machine tool drives the transmission rod 2 to swing, and then drives the tool electrode 1 and the universal adjustable fixture to move, so as to realize that the discharge end 101 of the tool electrode 1 makes an eccentric movement around the central axis of the inner cavity of the stainless steel tube 6. In this way, the discharge end 101 of the tool electrode is used for electrical discharge machining around the end face of the stainless steel tube 6. The machining direction 7 is the circumferential direction around the outer end face of the stainless steel tube 6, and the center line of the circumferential direction coincides with the central axis of the inner cavity of the stainless steel tube 6.

[0183] Specifically, before the tool electrode 1 makes an eccentric movement, it is necessary to adjust the center of the inner circle of the discharge end 101 of the tool electrode 1 to coincide with the central axis of the stainless steel tube 6, and there should be a margin gap between the discharge end 101 and the outer end face of the stainless steel tube 6. That is, the diameter of the inner circle of the discharge end 101 is larger than the outer diameter of the stainless steel tube 6. For example, the diameter of the inner circle is 10 to 20 mm, which is 5 to 10 times the outer diameter of the stainless steel tube 6. In this way, it is easy to determine the value of the single-sided feed rate O1O2 during the electrical discharge machining process.

[0184] Among them, the unilateral feed rate O1O2 satisfies:

[0185] O1O2=S1+(H1-H2)-S2

[0186] Where O1 represents the center point of the discharge terminal 101 of the tool electrode 1;

[0187] O2 indicates the center point of the inner cavity of the stainless steel pipe 6;

[0188] H1 is the wall thickness of stainless steel pipe 6;

[0189] H2 is the wall thickness of the fracture groove 601;

[0190] S1 indicates that there is a margin gap between the discharge terminal 101 and the outer end face of the stainless steel tube 6.

[0191] S2 is the machining clearance, which refers to the closest distance between the working end 102 and the end face of the stainless steel tube 601 when the tool electrode 1 moves eccentrically.

[0192] Wherein, S1 satisfies:

[0193]

[0194] Among them, S 11 S 12 S 13 S14 The actual clearance value between four points selected on the discharge end 101 of the tool electrode 1 and the outer end face of the stainless steel tube 6 is given. These four points are evenly distributed on the discharge end 101.

[0195] For example, S 11 S 12 S 13 S 14 The corresponding values ​​are 2.055mm, 2.060mm, 2.065mm, and 2.050mm, respectively. At this time, S1 = 2.058mm.

[0196] The machining gap S2 is set to 10-50 μm to meet the requirements of electrical discharge machining.

[0197] For example, S2 = 10 μm; H1 = 0.5 mm, H2 = 0.3 mm, S1 = 2.058 mm, and O1O2 = 2.248 mm.

[0198] Among them, the automatic centering module on the machine tool can be used to measure S. 11 S 12 S 13 S 14 If the four values ​​are equal, the center of the inner circle 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.

[0199] Among them, after the center of the discharge end 101 of the machine tool adjustment tool electrode 1 is aligned with the central axis of the inner cavity of the stainless steel tube 6, the actual measured S 11 S 12 S 13 S 14 The closer the four values ​​are, the more accurate the value of S1 will be, and the more accurate the single-sided feed amount O1O2 will be. In this way, the accuracy of the machining gap can be ensured during the eccentric movement of the tool electrode 1, thereby ensuring the machining depth of the working end 102 and ensuring the dimensional accuracy of the machined break groove 601.

[0200] Specifically, after the center of the discharge end 101 of the adjustment tool electrode 1 is aligned with the central axis of the inner cavity of the stainless steel tube 6, the machine tool drives the tool electrode 1 to make an eccentric movement. The detailed process is as follows.

[0201] The movement trajectories of the center point O1 of the discharge terminal 101 of the tool electrode 1 and the center point O2 of the inner cavity of the stainless steel tube 6 are described below:

[0202] Move tool electrode 1 so that O1 is away from O2. The moving distance is the same as the unilateral feed amount O1O2. At this time, the distance between O1 and O2 is O1O2.

[0203] With O2 as the center and O1O2 as the radius, rotate O1 around O2. At this time, the trajectory of O1 is a circle with O2 as the center and O1O2 as the radius.

[0204] During the movement of O1, when the closest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10μm, the power supply device is turned on to deliver a pulse voltage to the tool electrode 1 and the stainless steel tube 6, and the metal on the surface of the stainless steel tube 6 is etched at a processing speed of 0.04g / min until the distance between O1 and O2 is O1O2, and then O1 moves in a circular motion around O2.

[0205] To further illustrate the motion trajectory of tool electrode 1, an arbitrary point O3 on discharge terminal 101 is selected, and the trajectory of O3 is used for illustration, as follows:

[0206] Move tool electrode 1 so that O3 moves toward O2, and the moving distance is O1O2;

[0207] When O1 rotates around O2, the trajectory of O3 is a circle with the initial position of O3 as the center and O1O2 as the radius.

[0208] During the movement of O3, when the closest distance between the end face of the discharge end 101 and the surface of the stainless steel tube 6 reaches 10μm, the power supply device is turned on to deliver a pulse voltage to the tool electrode 1 and the stainless steel tube 6, and the metal on the surface of the stainless steel tube 6 is etched at a processing speed of 0.04g / min until the moving distance of O3 reaches O1O2. Then, O3 moves in a circle with its initial position as the center.

[0209] Thus, during the eccentric movement of the tool electrode 1, the distance between the inner circular end face of the discharge end 101 and the outer surface of the stainless steel tube 6 changes continuously. The distance between each part of the inner circular end face of the discharge end 101 and the outer end face of the stainless steel tube 6 changes from close to far away. Consequently, the discharge end 101 changes from the working state to the non-working state, that is, the dynamic transformation between the working end 102 and the non-working end 103 is realized.

[0210] The discharge end 101 has a clearance between itself and the outer end face of the stainless steel tube 601 to ensure that the non-working end 103 at the discharge end 101 and the end face of the stainless steel tube 6 have a sufficiently large non-processing clearance, thereby 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, when the tool electrode 1 moves eccentrically, the working end 102 and the non-working end 103 can be dynamically switched.

[0211] 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, for example, kerosene, mineral oil, or deionized water; when a 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 given conditions is broken down, forming a discharge channel. Due to the very small cross-sectional area of ​​the channel and the extremely short discharge time, the energy is highly concentrated (10). 6 W / cm 2 The instantaneous high temperature generated in the discharge area is sufficient to melt or even evaporate the metal on the surface of the stainless steel tube 6, resulting in a small pit. After the first pulse discharge ends, after a very short interval, the second pulse discharges at the closest point between the other electrodes. This process continues at a high frequency, and the tool electrode 1 continuously feeds into the stainless steel tube 6. Its shape is eventually replicated on the stainless steel tube 6, forming the required machining surface. During the machining process, although a small portion of the total energy is released onto the tool electrode 1, causing wear on the tool electrode 1, the working end 102 at the discharge end 101 is constantly changing position due to the eccentric movement of the discharge end 101 around the central axis of the inner cavity of the stainless steel tube 6. This reduces wear on the tool electrode 1 by avoiding continuous machining of the working end 102. Consequently, at each moment of machining, the working end 102 of the discharge end 101 maintains a relatively complete shape, improving machining accuracy.

[0212] For example, during the processing, the electrical parameters satisfy:

[0213] Pulse width 30–60 μs, pulse interval 20–30 μs, average machining current 0.8–2 A, average machining voltage 30–60 V.

[0214] Specifically, during processing, the tool electrode 1 is eccentrically moved by the machine tool control, while the stainless steel tube 6 remains stationary.

[0215] The tool electrode 1 is connected to a drive device installed on the machine tool. The drive device includes a transmission rod 2. During processing, the machine tool controls the transmission rod 2 to swing, thereby driving the tool electrode 1 to make an eccentric motion through the transmission rod 2.

[0216] Specifically, the transmission rod 2 swings clockwise within the swing plane YZ, which is parallel to the plane where the discharge end 101 is located. In this way, the tool electrode 1 achieves eccentric movement around the central axis of the inner cavity of the stainless steel tube 6.

[0217] For example, during the processing, the non-electrical parameters satisfy:

[0218] The oscillation speed of the drive component is 0.4 to 0.6 rpm, the machining gap is 10 to 50 μm, and the machining speed is 0.02 to 0.045 g / min.

[0219] In this way, the discharge end 101 of the tool electrode 1 moves eccentrically around the central axis of the inner cavity of the stainless steel tube 6 for one revolution, which can complete the processing of the stainless steel tube break groove 601, achieving one-time processing and significantly improving processing efficiency.

[0220] Compared with the prior art, the present invention adjusts the tilt angle of the tool electrode 1 on the horizontal plane through the first adjustment part of the universal adjustable fixture; the tilt angle of the tool electrode 1 on the YZ plane of the machine tool is determined according to the detection value of the dial indicator and the time and speed of the dial indicator movement; by comparing the angle scale value on the first connecting body 18 and pushing the angle adjustment bolt 21 to the corresponding scale, the tilt angle of the tool electrode 1 on the YZ plane of the machine tool can be adjusted with high precision, thereby realizing the alignment of the tool electrode 1, which is convenient to operate and improves processing efficiency and accuracy.

[0221] During processing, the ultra-thin stainless steel tube 6 is simply placed in the V-shaped groove on the equal height positioning block 3 and the auxiliary bearing block 4, and the upper surface of the ultra-thin stainless steel tube is limited by the clamping plate 5. This allows for the clamping and positioning of the ultra-thin stainless steel tube, which is convenient and ensures the stability of the ultra-thin stainless steel tube 6 during processing.

[0222] The discharge end 101 of the tool electrode 1 of the present invention is annular and moves eccentrically around the outer end face of the ultra-thin stainless steel tube 6. During this process, the distance between the end face of the discharge end 101 and the end face to be processed of the ultra-thin stainless steel tube 6 is constantly changing. The closer end is the working end 102, and the farther end is the non-working end 103. Thus, the outer end face of the ultra-thin stainless steel tube 6 is subjected to electrical discharge machining through the working end 102. That is, along the machining direction, the position of the working end 102 on the inner circular end face of the discharge end 101 is constantly changing, that is, the inner circular end face of the discharge end 101 is closer to the ultra-thin stainless steel tube 6. When the discharge end 101 is on the outer end face of the slender 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-slender stainless steel tube 6, the end face transforms into the non-working end 103, realizing the dynamic transformation between the working end 102 and the non-working end 103. In this way, the working end 102 of the tool electrode 1 is not in a continuous processing state, which greatly reduces the wear on the working end 102 of the tool electrode 1, achieving a tool electrode wear of ≤1%, thereby reducing the deformation of the working end face of the tool electrode 1, and thus improving the processing accuracy of the fracture groove 601 of the ultra-slender stainless steel tube.

[0223] The discharge end 101 of the tool electrode 1 of the present invention is fitted onto the ultra-thin stainless steel tube 6 and moves eccentrically. During processing, the distance between the discharge end 101 and the ultra-thin stainless steel tube 6 decreases and then increases. During the process of decreasing distance, metal debris is generated between the discharge end 101 and the stainless steel tube 6. At this time, some of the metal debris will be discharged through the processing gap with the working fluid. During the process of increasing distance, the distance between the discharge end 101 and the stainless steel tube 6 can increase by nearly 200 times, which significantly improves the efficiency of metal debris discharge. This avoids the accumulation of metal debris at the discharge end 101 due to untimely discharge, thereby reducing the wear of the tool electrode 1 and avoiding the risk of short circuit caused by direct connection of the tool electrode 1 to the stainless steel tube 6 through metal debris.

[0224] By having the discharge end 101 of the tool electrode 1 made eccentric motion on the ultra-thin stainless steel tube 6, metal chips can be efficiently discharged, thereby enabling electrical discharge machining with a smaller machining gap. This reduces the machining current and voltage, lowers the machining cost, and allows for the production of a fracture groove 601 with a lower surface roughness.

[0225] By adjusting the value of the single-sided feed, the fracture groove 601 with different wall thicknesses can be processed. By adjusting the shape of the discharge end 101 of the tool electrode 1, the size processing of different oblique angles α can be achieved, laying the foundation for rapid production and mass production of products.

[0226] The discharge end 101 of the tool electrode 1 of the present invention can complete the processing of the fracture groove 601 of the ultra-thin stainless steel tube by moving eccentrically around the central axis of the inner cavity of the ultra-thin stainless steel tube 6 once, thus achieving one-time processing and significantly improving processing efficiency.

[0227] Example 1

[0228] A device for processing the fracture groove of an ultra-slender stainless steel tube includes: a tool electrode 1 mounted on a machine tool, a universal adjustable clamp for aligning the tool electrode 1, a drive assembly for driving the tool electrode 1 to move eccentrically around the central axis of the inner cavity of the stainless steel tube 6, and a bearing assembly for clamping the stainless steel tube 6.

[0229] Specifically, one end of the tool electrode 1 is annular, and the inner circle of this annular ring matches the shape of the breakage groove 601. The other end of the tool electrode 1 is a conductive end 104, which is electrically connected to an output end of a power supply device installed on the machine tool to introduce current and transmit it to the inner circle end. At this time, the inner circle end is the discharge end 101, which is fitted onto the outer end face of the stainless steel tube 6. During processing, the stainless steel tube 6 is electrically connected to the other output end of the power supply device, and the discharge end 101 of the tool electrode 1 moves eccentrically around the central axis of the inner cavity of the stainless steel tube 6. During the eccentric movement of the tool electrode 1, the distance between the end face of the discharge end 101 and the end face of the stainless steel tube 6 to be processed is constantly changing. A distance of 10-50 μm is the working state, i.e., the working end 102, and a distance greater than 50 μm is the non-working state, i.e., the non-working end 103. The processing trajectories of all working ends 102 together constitute the ultra-slender stainless steel tube breakage groove 601.

[0230] The center of the inner circle 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 there is a clearance between the discharge end 101 and the outer end face of the stainless steel tube 6. The diameter of the end face of the discharge end 101 is 20mm, which is 10 times the outer diameter of the stainless steel tube 6, so as to facilitate the determination of the value of the single-sided feed amount O1O2. During processing, the tool electrode 1 is driven to swing by the drive assembly. At this time, 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 tube 6.

[0231] Among them, the automatic centering module on the machine tool is used to measure S. 11 S 12 S 13 S 14 The corresponding values ​​are 2.055mm, 2.060mm, 2.065mm, and 2.050mm, respectively. At this time, S1 = 2.058mm.

[0232] Where S2 = 10 μm; H1 = 0.5 mm, H2 = 0.3 mm, S1 = 2.058 mm, and O1O2 = 2.248 mm.

[0233] When the center of the discharge end 101 of the adjustment tool electrode 1 coincides 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 drive assembly.

[0234] The conductive end 104 of the tool electrode 1 is electrically connected to one output end of the power supply device installed on the machine tool, and the stainless steel tube 6 is electrically connected to the other output end of the power supply device. The power supply device includes a pulse power supply, and its two output ends are respectively connected to the positive and negative terminals of the pulse power supply to output pulse voltage.

[0235] During the processing, the electrical parameters must meet the following requirements:

[0236] Pulse width 40μs, pulse interval 26μs, average machining current 1A, average machining voltage 40V.

[0237] Specifically, the aforementioned drive assembly includes a transmission rod 2, one end of which is connected to the tool electrode 1, and the other end of which is mounted on a machine tool. The machine tool can control the transmission rod 2 to swing, thereby causing the discharge end 101 of the tool electrode 1 to move eccentrically around the central axis of the inner cavity of the stainless steel tube 6. During processing, the stainless steel tube 6 remains stationary.

[0238] During the processing, the non-electrical parameters satisfy the following:

[0239] The swing speed of transmission rod 2 is 0.5 rpm, the machining gap S2 is 10 μm, the machining speed is 0.04 g / min, and the single-sided feed amount O1O2 is 2.248 mm.

[0240] Specifically, the universal adjustable clamp includes a clamping part, a first adjusting part, and a second adjusting part; wherein, the clamping part includes a reference base 10 and a clamping seat 11 mounted on the reference base 10, wherein the adjacent surfaces of the clamping seat 11 and the reference base 10 form a clamping space for mounting the tool electrode 1. During installation, the upper end of the tool electrode 1 is mounted in the clamping space, and includes a fastening screw 12 for adjusting the clamping force on the tool electrode 1. The fastening screw 12 is screwed onto the clamping seat 11, and one end of the screw passes through the clamping seat 11 and is located in the clamping space.

[0241] The inner end face of the clamping space that connects with the tool electrode 1 is a V-shaped surface with an angle of 90°.

[0242] The first adjustment part includes a first fixing seat 13 and a second fixing seat 14 distributed vertically. The second fixing seat 14 is installed at the lower end of the first fixing seat 13 by four vertical screws 15, and there is a gap between the adjacent surfaces of the first fixing seat 13 and the second fixing seat 14. One end of the vertical screw 15 passes through the first fixing seat 13 and the second fixing seat 14 and is screwed to the first fixing seat 13 and slidably connected to the second fixing seat 14. A nut is provided at the bottom of the vertical screw 15 to limit the second fixing seat 14 in a direction perpendicular to the second fixing seat 14 so that the tilt angle of the second fixing seat 14 in the horizontal direction can be adjusted by rotating the vertical screw 15.

[0243] An insulating plate 16 is fixedly installed at the lower end of the second fixed base 14, and the reference base 10 is fixedly connected to the lower end face of the insulating plate 16.

[0244] The second adjustment part includes a clamp head 17, a first connecting body 18, a second connecting body 19, and a rotating body 20. 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. The upper end of the rotating body 20 is rotatably connected to the first connecting body 18 in the horizontal direction. The lower end of the rotating body 20 is fixedly connected to the second connecting body 19. The lower end of the second connecting body 19 is fixedly connected to the top of the first fixed seat 13.

[0245] 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 mounted on the top wall of the cavity. An angle adjusting bolt 21 is installed at one end of the rotating body 20. One end of the angle adjusting bolt 21 is screwed onto the rotating body 20, and the other end passes through the cavity wall of the first connecting body 18 and is located outside the first connecting body 18. A slot 22 is provided on the side end face of the first connecting body 18 so that the angle adjusting bolt 21 can slide in the slot 22 when the rotating body 20 rotates.

[0246] The groove 22 has a scale for the rotation angle along its length, which allows for precise control of the angle of the rotation adjustment bolt and improves the alignment accuracy of the tool electrode on the YZ plane of the machine tool.

[0247] The angle β pushed by the angle adjusting bolt 21 satisfies:

[0248]

[0249] Wherein, S: with the discharge end face of tool electrode 1 as the reference plane, the dial indicator is moved in the Y-axis direction of the machine tool, and the distance the dial indicator needle moves is S;

[0250] v1 is the speed at which the dial indicator moves;

[0251] t1 is the time it takes for the dial indicator to move.

[0252] Specifically, the motion assembly includes a transmission rod 2, one end of which is fixedly connected to the reference base 10, and the transmission rod 2 is parallel to the center line of the discharge end 101 of the tool electrode 1. During the processing, the other end of the transmission rod 2 is mounted on the machine tool, so that the machine tool drives the transmission rod 2 to swing, and then drives the tool electrode 1 and the universal adjustable fixture to move, so as to realize that the discharge end 101 of the tool electrode 1 makes an eccentric movement around the central axis of the inner cavity of the stainless steel tube 6.

[0253] Specifically, the load-bearing components include a height positioning block 3 and an auxiliary support block 4 installed on the machine tool to place the stainless steel pipe 6 on the height positioning block 3 and the auxiliary support block 4 to clamp the stainless steel pipe 6.

[0254] The system includes two equal-height positioning blocks 3, which are located on both sides of the stainless steel pipe 6 to be processed, with a distance of 30mm between them.

[0255] The system includes two auxiliary support blocks 4 and two equal-height positioning blocks 3 located between the two auxiliary support blocks 4, so as to support and position the two ends of the stainless steel pipe 6 through the two auxiliary support blocks 4.

[0256] The upper surfaces of the level positioning block 3 and the auxiliary bearing block 4 are flush, and a V-shaped groove is provided on the upper surfaces of the level positioning block 3 and the auxiliary bearing block 4. The stainless steel pipe 6 is placed in the V-shaped groove to limit the movement of the stainless steel pipe 6.

[0257] Furthermore, a clamping plate 5 is provided on the leveling positioning block 3. The clamping plate 5 covers the V-groove and is engaged with the leveling positioning block 3 to limit the movement of the stainless steel tube 6 and further improve the stability of the stainless steel tube 6. For example, the angle of the V-groove is 90° and the depth is 10mm.

[0258] Before placing the stainless steel tube 6 on the leveling block 3, the tool electrode 1 needs to be aligned first. Then, the stainless steel tube 6 is inserted into the discharge end 101 of the tool electrode 1. Finally, the leveling block 3, the auxiliary bearing block 4 and the clamping plate 5 are used to clamp the stainless steel tube 6, and the leveling block 3 and the auxiliary bearing block 4 are used to align the stainless steel tube 6.

[0259] Example 2

[0260] A method for processing a fracture groove in an ultra-slender stainless steel tube includes the following steps:

[0261] Step 1: Use a universal adjustable clamp to align the tool electrode;

[0262] Specifically, the spatial position of the tool electrode 1 is adjusted by using the spatial position of the universal adjustable clamp 5.

[0263] The tool electrode 1 is fixed on the universal adjustable fixture 5. A dial indicator is used to align the reference surface of the tool electrode 1. The universal adjustable fixture is adjusted so that the relative position error between the tool electrode 1 and the three dimensions of the XYZ axis of the machine tool is ≤0.01mm.

[0264] Specifically, select a reference plane in the XYZ three-dimensional direction on the tool electrode, touch the dial indicator head to the reference plane respectively, and then move the dial indicator. If the dial indicator needle on the dial shows a movement of 0-10μm, the accuracy meets the requirements, and the alignment process ends. If the dial indicator needle on the dial shows a movement of more than 10μm, the accuracy does not meet the requirements. Use the universal adjustable fixture to adjust the position of the tool electrode in the three dimensions on the machine tool until the dial indicator needle on the dial shows a movement of 0-10μm, thereby achieving alignment of the tool electrode.

[0265] In this process, a dial indicator is used to align the tool electrode in the XYZ directions of the machine tool. After alignment, the value of the movement of the dial indicator needle in the XYZ directions is the alignment error, which is the relative position error.

[0266] Among them, small planes can be machined on the tool electrode as reference surfaces in the XYZ axes of the machine tool.

[0267] For example, in the Z-axis direction of the machine tool, a dial indicator is used to align the tool electrode. Using the discharge end face of the tool electrode as a reference plane, the dial indicator head touches the upper horizontal plane of the transmission rod. The dial indicator is moved up and down. If the dial indicator needle moves 0-10 μm, the position of the tool electrode in the Z-axis direction meets the requirements. If the dial indicator needle moves more than 10 μm, the position of the tool electrode is adjusted using the first adjustment part of the universal adjustable fixture. After adjustment, the dial indicator is used to continue testing until the dial indicator moves within 0-10 μm.

[0268] The adjustment process of the universal adjustable clamp is as follows:

[0269] Specifically, first install the tool electrode into the clamping part and then tighten the tool electrode using fastening screws;

[0270] Next, with the discharge end face of the tool electrode as the reference plane, the dial indicator touches the reference plane and moves in the Z-axis direction of the machine tool. If the dial indicator needle moves 0-10μm, the tool electrode does not need to be adjusted in the front-back direction of the XY plane of the machine tool. If the dial indicator needle moves more than 10μm, the position of the tool electrode needs to be adjusted through the first adjustment unit.

[0271] During the upward movement of the dial indicator, if the pointer moves clockwise, the upper end of the tool electrode tilts toward the reference surface; if the pointer moves counterclockwise, the upper end of the tool electrode tilts toward the reference surface in the opposite direction. At this time, by adjusting the upper and lower spatial positions of the vertical screws near both sides of the discharge end face, the tool electrode can be aligned in the front-back direction of the XY plane of the machine tool.

[0272] The tool electrode is aligned in the front-to-back direction of the XY plane by rotating the vertical screw at the higher position clockwise and the vertical screw at the lower position counterclockwise.

[0273] Next, using the upper end face of the second fixed seat as the reference plane, the dial indicator head touches the reference plane and moves in the Y-axis direction of the machine tool. If the dial indicator needle moves 0-10μm, the position of the tool electrode does not need to be adjusted in the left and right directions of the XY plane of the machine tool. If the dial indicator needle moves more than 10μm, the position of the tool electrode needs to be adjusted through the first adjustment part.

[0274] The upper surface of the tool electrode is a plane, which is parallel to the center line of the discharge end and is connected to the lower surface of the insulating plate. The upper surface of the second fixed seat is parallel to the upper surface of the tool electrode. Thus, the tool electrode can be aligned in the left and right directions of the XY plane of the machine tool by using the upper surface of the second fixed seat as the reference plane.

[0275] During the movement of the dial indicator to the right, if the pointer moves clockwise, the right end of the second fixed base will be too high. In this case, the vertical screw near the right end of the second fixed base can be adjusted to rotate it clockwise, or the vertical screw near the left end of the second fixed base can be adjusted to rotate it counterclockwise.

[0276] During the movement of the dial indicator to the right, if the indicator needle moves counterclockwise, the left end of the second fixed seat will be too high. In this case, the vertical screw near the left end of the second fixed seat can be adjusted to rotate clockwise, or the vertical screw near the right end of the second fixed seat can be adjusted to rotate counterclockwise. This will allow the tool electrode to be aligned in the left and right directions of the XY plane of the machine tool.

[0277] Next, with the discharge end face of the tool electrode as the reference plane, the dial indicator head touches the reference plane and moves in the Y-axis direction of the machine tool; if the dial indicator needle moves 0-10μm, the position of the tool electrode does not need to be adjusted in the YZ plane direction of the machine tool; if the dial indicator needle moves more than 10μm, the position of the tool electrode needs to be adjusted through the second adjustment unit.

[0278] During the movement of the dial indicator to the right, if the pointer moves clockwise, the tool electrode tilts clockwise. At this time, turn the angle adjustment screw counterclockwise. If the pointer moves counterclockwise, the tool electrode tilts counterclockwise. At this time, turn the angle adjustment screw clockwise.

[0279] Among them, the dial indicator is controlled by the machine tool to move in the X, Y, and Z directions, and the moving time and speed of the dial indicator are recorded to obtain the tilt angles of the tool electrode in the X, Y, and Z directions. Among them, in the YZ plane direction of the machine tool, the tool electrode is aligned with the dial indicator, and the moving time of the dial indicator is recorded as t1, the speed is v1, and the distance that the pointer of the dial indicator rotates clockwise is S; if 0μm < S < 10μm, at this time, there is no need to adjust the rotation angle adjustment bolt; if S > 10μm, at this time, the rotation angle adjustment bolt needs to be adjusted counterclockwise. Taking the center of the rotating body as the center of the circle, the angle β pushed by the rotation angle adjustment bolt satisfies:

[0280]

[0281] Among them, when it is necessary to push the rotation angle adjustment bolt counterclockwise, first rotate the rotation angle adjustment bolt counterclockwise so that the rotation angle adjustment bolt is movably connected to the first connecting body, and then push the rotation angle adjustment bolt counterclockwise with a pushing angle of -β. During this process, adjust according to the scale at the notch of the first connecting body, and the tool electrode can be aligned in the YZ plane direction of the machine tool. After the alignment is completed, rotate the rotation angle adjustment bolt clockwise to press it against the end face of the first connecting body to prevent the rotation angle adjustment bolt from sliding.

[0282] In this way, the alignment process of the tool electrode is realized.

[0283] Step 2: Clamp the stainless steel pipe 6 with the bearing component and align the stainless steel pipe 6.

[0284] Specifically, first fix two equal-height positioning blocks 3 and two auxiliary support blocks 4 on the workbench 9, use a dial indicator to align its side surface parallel to the X axis of the machine tool, and use the machine tool to adjust the positions of the equal-height positioning blocks 3 and the auxiliary bearing blocks 4, where the parallelism error ≤ 0.01mm.

[0285] Then place the stainless steel pipe 6 on the equal-height positioning blocks 3. Before placing it, pass the stainless steel pipe 6 through the inner circular end at the lower end of the tool electrode 1, and ensure that the stainless steel pipe 6 is in a horizontal position through the equal-height positioning blocks 3. The distance between the two equal-height positioning blocks 3 is 30mm;

[0286] Next, place both ends of the stainless steel pipe 6 on the auxiliary support blocks 4, and finally fix it with the clamping plate 5.

[0287] Step 3: Use the machine tool to adjust the center line of the discharge end 101 of the tool electrode 1 to coincide with the inner cavity central axis of the stainless steel pipe 6;

[0288] Specifically, first move the bearing component in the X-axis direction through the machine tool to adjust the position of the stainless steel pipe 6 so that the machining position of the stainless steel 6 is located inside the discharge end 101 of the tool electrode 1;

[0289] Next, the S is measured using the machine tool's automatic centering module. 11 S 12 S 13 S 14 If the four values ​​are equal or the error is within ±0.02mm, then the center of the discharge end 101 of the tool electrode 1 is aligned with the central axis of the inner cavity of the stainless steel tube 6. If they are not aligned, the position of the bearing component is adjusted by the machine tool until the requirements are met.

[0290] Step 4: Using kerosene and water as the working fluid, perform electrical discharge machining on the stainless steel tube 6 using the tool electrode 1 in the working fluid.

[0291] S101: Control the discharge end 101 of the tool electrode 1 to move eccentrically around the central axis of the inner cavity of the stainless steel tube 6.

[0292] Specifically, the machine tool drives the transmission rod 2 to swing in the YZ plane, thereby controlling the discharge end 101 of the tool electrode 1 to perform eccentric motion around the central axis of the inner cavity of the stainless steel tube 6 via the transmission rod 2; the direction of eccentric motion 8 is as follows: Figure 9 As shown.

[0293] The swing speed of transmission rod 2 is 0.5 rpm;

[0294] S 11 S 12 S 13 S 14 The actual measured values ​​were 2.055mm, 2.060mm, 2.065mm, and 2.050mm, respectively. At this time, S1 = 2.058mm.

[0295] The machining clearance S2 is 10 μm;

[0296] Single-sided feed rate O1O2=S1+(H1-H2)-S2=2.058+(0.5-0.3)-0.01=2.248mm;

[0297] The processing speed is 0.04 g / min.

[0298] S102: When the tool electrode 1 is in eccentric motion, energize the tool electrode 1 to perform electrical discharge machining.

[0299] Specifically, the electrical parameters meet the following requirements:

[0300] Pulse width 40μs, pulse interval 26μs, average machining current 1A, average machining voltage 40V.

[0301] In this way, the discharge end of the tool electrode can complete the processing of the stainless steel tube break groove by eccentrically moving around the central axis of the inner cavity of the stainless steel tube for one revolution, achieving one-time processing and significantly improving processing efficiency.

[0302] The above processing method was used to process the fracture grooves of the ultra-slender stainless steel tubes #01-#10. The processing parameters are shown in Table 1 below.

[0303] Table 1 Processing Parameters

[0304]

[0305] Processing requirements: The wall thickness of the fracture groove is 0.3±0.05mm, and the bevel angle α is 90°.

[0306] The test results are shown in Table 2 below.

[0307] Table 2 Detection Results

[0308]

[0309]

[0310] The electrode consumption ratio is E / W*100%, where E is the change in the diameter of the discharge end of the tool electrode, and W is the initial diameter of the inner end of the tool electrode.

[0311] As shown in Table 2, the average depth of the fracture grooves of the 10 stainless steel tubes processed by this invention is 0.2146 mm, the standard deviation is 0.01427, and the coefficient of variation is 0.07. The fracture groove angle is 90°. The average wall thickness of the fracture groove is 0.299 mm, the standard deviation is 0.006681, and the coefficient of variation is 0.02. It can be seen that the processing method of this invention can realize the processing of fracture grooves on ultra-thin stainless steel tubes, and the processed fracture grooves have high precision and stability, will not damage the ultra-thin stainless steel tubes, and have less wear on the tool electrode.

[0312] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0313] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A processing device for V-grooves in ultra-slender, thin-walled tubes, characterized in that: It includes a tool electrode mounted on a machine tool, a universal adjustable clamp for aligning the tool electrode, a drive assembly for controlling the movement of the tool electrode, and a load-bearing assembly for clamping thin-walled tubes. One end of the tool electrode includes multiple electrical discharge machining points arranged around the circumference of the thin-walled tube. The working state of the multiple electrical discharge machining points arranged around the circumference of the thin-walled tube realizes the machining of V-grooves on the surface to be machined. The discharge end of the tool electrode is sleeved on the thin-walled tube. During processing, the discharge end of the tool electrode moves eccentrically around the central axis of the inner cavity of the thin-walled tube. One end of the tool electrode is a discharge end, and the discharge end includes a plurality of electrical discharge machining points arranged around the circumference of the thin-walled tube. The same electrical discharge machining point includes a working state and a non-working state. During processing, multiple electrical discharge machining points arranged around the circumference of the thin-walled tube form a continuous ring, and the inner end of the ring matches the shape of the V-groove; during processing, the tool electrode is eccentrically moved by the machine tool control, and the thin-walled tube remains stationary. The processing direction is circumferential around the outer end face of the thin-walled tube, and the center line of this circumferential direction coincides with the central axis of the inner cavity of the thin-walled tube. By changing the distance between the EDM point and the surface to be processed, the same EDM point can be in a working or non-working state.

2. The processing apparatus according to claim 1, characterized in that: The universal adjustable fixture includes a clamping part for clamping a tool electrode, a first adjusting part for aligning the tool electrode on the XY plane of the machine tool, and a second adjusting part for aligning the tool electrode on the YZ plane of the machine tool. From bottom to top, the clamping part, the first adjusting part, and the second adjusting part are sequentially connected to each other.

3. The processing apparatus according to claim 2, characterized in that: The first adjustment part includes a first fixed seat and a second fixed seat distributed on the upper and lower sides. The second fixed seat is installed at the lower end of the first fixed seat by a plurality of vertical screws, and the clamping part is installed at the lower end of the second fixed seat. Wherein, the adjacent surfaces of the first fixing seat and the second fixing seat are provided with a gap; The tilt angle of the second fixed seat in the XY direction of the machine tool is adjusted by adjusting the position of the vertical screw in the Z-axis direction of the machine tool.

4. The processing apparatus according to claim 3, characterized in that: The second adjustment unit includes a clamp head mounted on a machine tool, a first connecting body fixedly connected to the clamp head, a rotating body rotatably connected to the first connecting body in the horizontal direction, and a second connecting body fixedly connected to the rotating body; the second connecting body is connected to the first fixed base. The rotating body is equipped with an angle adjustment bolt, which allows the spatial position of the rotating body to be adjusted.

5. The processing apparatus according to claim 4, characterized in that: One end of the angle adjusting bolt is screwed onto the rotating body so that the rotating body can be rotated when the angle adjusting bolt is pushed. The lower end of the first connecting body has a cavity for placing the rotating body. The rotating body is installed in the cavity. A slot is provided on the side wall of the cavity. The other end of the angle adjusting bolt is slidably installed in the slot.

6. The processing apparatus according to claim 5, characterized in that: When adjusting the tilt angle of the tool electrode on the YZ plane of the machine tool by pushing the angle adjusting bolt, the pushing angle β satisfies: Where S is the distance the dial indicator needle moves; v1 is the speed at which the dial indicator moves; and t1 is the time it takes for the dial indicator to move.

7. The processing apparatus according to claim 2, characterized in that: The drive assembly includes a transmission rod, one end of which is mounted on the clamping part. During processing, the other end of the transmission rod is mounted on the machine tool so that the clamping part can be moved through the transmission rod, thereby moving the tool electrode.

8. A method for processing a V-groove in an ultra-slender, thin-walled tube, characterized in that: This includes using the processing apparatus according to any one of claims 1-7 to perform electrical discharge machining on V-grooves of thin-walled tubes.

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