Rotating ball array electrode for electric discharge machining and array feature machining method

Abstract

The present invention discloses a rotary ball array electrode for electrospark machining (EDM) and an array feature machining method, relating to the technical field of EDM equipment. The electrode comprises a clamping spindle, a rotating disk rotatably connected to the lower end of the clamping spindle, a clamping mechanism fixedly connected to the lower end of the rotating disk, a ball squeezing assembly clamped and fixedly connected to the lower end of the clamping mechanism, the ball squeezing assembly comprising a clamping limit plate, a ball pressure plate, and a lifting support assembly, the lifting support assembly comprising a lifting support bolt, a lifting control nut, and a compression spring, a support plate disposed below the ball pressure plate, the support plate fixedly connected to the clamping spindle, a plurality of supporting ball holes distributed in an array, each supporting ball hole being used to place a discharge ball, the discharge ball protruding from the lower surface of the support plate, the ball pressure plate rotating and squeezing each discharge ball, causing each discharge ball to rotate in the same horizontal plane. The present invention can achieve efficient and high-quality batch machining of array features.

Description

Technical Field

[0001] The present invention relates to the technical field of electric spark machining equipment, and in particular to a rotary ball array electrode for electric spark machining and an array feature machining method. Background Art

[0002] Microlens arrays, with their excellent optical properties, have widespread and important applications in the optical field. Molding has proven to be a high-quality, efficient method for mass-producing microlens array lenses. Molding relies on the precise shaping of preforms using a mold. Therefore, the manufacture of microlens array molds is crucial for this process. Currently, the most common manufacturing techniques for array feature molds include ultra-precision machining and electrospark forming.

[0003] Ultra-precision cutting processing represented by single-point diamond cutting technology mainly uses diamond tools to turn or mill mold blanks. The amount of material removed is extremely small, usually in the micron and nanometer levels, so excellent processing surface quality and morphology can be obtained. Therefore, it has extremely wide applications in ultra-precision array feature mold processing.

[0004] As a non-contact, specialized machining method, EDM is not limited by the hardness of conductive metals and lacks the contact stress of cutting, effectively replicating surface topography. Therefore, it is widely used in mold manufacturing. For machining curved array features, existing EDM uses a forming electrode method, producing a reversed shape corresponding to the specified mold form.

[0005] Although ultra-precision cutting can achieve extremely high machining topography accuracy and surface roughness, its processing materials are greatly limited. Diamond tools can only process crystals, metals, and plastics such as copper, aluminum, and polymers such as PMMA. When processing carbon-containing steel materials, affinity causes carburization wear. When processing hard and brittle materials such as tungsten carbide and silicon carbide, severe friction damage to the tool directly affects the roughness, topography accuracy, and machinable area of ​​the machined surface. Furthermore, its cutting depth is relatively small, and its processing efficiency is extremely low for large-area feature arrays, making it impossible to achieve high-efficiency large-scale processing.

[0006] As for EDM, its processing efficiency is far superior to cutting due to its reverse handcuffing principle. However, it must be realized that the electrode loss during EDM cannot be ignored, especially when the array unit size becomes smaller. The electrode loss will become more prominent. The electrode loss will cause differences in the array feature morphology, ultimately affecting the surface quality. Moreover, for the overall array feature processing, it is almost impossible to correct the electrode loss, and the cost of forming the array electrode is high.

[0007] To sum up, it can be seen that the efficient and high-quality processing of array feature molds has always lacked an effective processing technology. Therefore, it is necessary to design a processing method to solve the problem of efficient and high-quality batch processing of array features. Summary of the Invention

[0008] The purpose of the present invention is to provide a rotary ball array electrode for electrospark machining and an array feature machining method to solve the problems existing in the above-mentioned prior art and to achieve efficient and high-quality batch machining of array features.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention provides a rotating ball array electrode for electrospark machining, comprising a clamping spindle, the lower end of the clamping spindle is rotatably connected to a rotating disk, the lower end of the rotating disk is fixedly connected to a clamping mechanism, the lower end of the clamping mechanism is clamped and fixedly connected to a ball squeezing assembly, the ball squeezing assembly comprises a clamping limit plate, a ball pressure plate and a lifting support assembly, the clamping limit plate is clamped and fixed to the lower end of the clamping mechanism by a column, the ball pressure plate is connected to the bottom of the clamping limit plate through a plurality of lifting support assemblies, the lifting support assembly comprises a lifting support bolt, a lifting control nut and a compression spring, the lifting support bolt passes through the ball pressure plate and the through holes on the clamping limit plate in sequence from the bottom The rear end of the hole is threadedly connected to the lifting control nut, and the compression spring is sleeved on the outside of the lifting support bolt. The compression spring is in a contracted state and its two ends are respectively against the ball pressure plate and the clamping limit plate. A support plate is provided under the ball pressure plate, and the support plate is fixedly connected to the clamping spindle through a connecting assembly. A plurality of supporting ball holes distributed in an array are provided on the support plate, and each supporting ball hole is used to place and support the discharge ball. The discharge ball protrudes from the lower surface of the support plate. The rotation of the rotating disk can drive the ball pressure plate to rotate around the vertical axis. The ball pressure plate rotates and squeezes each discharge ball, so that each discharge ball rotates in the same horizontal plane.

[0011] Preferably, the clamping mechanism includes a rotating chuck and a clamping nut, the rotating chuck is fixedly connected to the lower end of the rotating disk, the clamping nut is fixedly connected to the lower end of the rotating chuck, and the column is clamped and fixed in the clamping nut.

[0012] Preferably, the connecting assembly includes a fixing bolt, a transition load-bearing ring and a load-bearing bolt. The transition load-bearing ring is sleeved outside the clamping nut. The transition load-bearing ring is connected to the clamping spindle through a plurality of the fixing bolts and is connected to the support plate through a plurality of the load-bearing bolts.

[0013] Preferably, each of the fixing bolts is evenly connected to the transition load-bearing ring along the circumferential direction, and each of the load-bearing bolts is evenly connected to the transition load-bearing ring along the circumferential direction and is staggered with each of the fixing bolts.

[0014] Preferably, the support plate is a square support plate, and the number of the load-bearing bolts is four, with each of the four corners of the square support plate being connected with a load-bearing bolt.

[0015] Preferably, the number of the lifting support assemblies is four, and each of the lifting support assemblies is evenly connected to the ball pressure plate along the circumferential direction.

[0016] The present invention also provides a method for machining array features on a workpiece surface, using the above-mentioned rotating ball array electrode for electrospark machining, comprising the following steps:

[0017] S1: placing one discharge ball into each of the support ball holes on the support plate;

[0018] S2: Adjusting the lifting control nut at multiple positions so that the ball pressure plate can press each of the discharge balls and level the ball pressure plate;

[0019] S3: Turn on the rotation function. The rotation of the rotating disk drives the ball pressure plate to rotate around the vertical axis. The pressure of the ball pressure plate on the discharge balls and the friction coefficient of the friction pair are set. The ball pressure plate rotates and, under the action of friction force, causes the discharge balls to rotate in the same horizontal plane.

[0020] S4: starting the EDM program, and realizing a one-time multi-point forming process of the array feature by setting the distance between the discharge ball and the workpiece;

[0021] S5: Move the clamping spindle, set the single movement distance of the clamping spindle according to the distance between the discharge balls, perform sequential processing according to the program, and form large-area curved surface array features on the surface of the workpiece.

[0022] Preferably, in step S2, the pressure between each discharge ball and the ball pressure plate is detected respectively by a pressure sensor, and the lifting control nut is adjusted to make each detected pressure value equal to achieve leveling of the ball pressure plate.

[0023] Preferably, during the processing, after the rotation loss of the discharge ball reaches the loss limit value, the clamping spindle is moved to the specified friction block area, the lifting control nut is adjusted so that each discharge ball is in a free state, and the ball is fed vertically downward by a specified distance, so that a friction pair is formed between the lower surface of each discharge ball and the friction block to achieve the update of the discharge area. After the discharge area is updated, the clamping spindle is moved back to the processing area to continue processing.

[0024] Preferably, when the processed surfaces of the discharge beads are all worn out to the limit, the lifting control nut is adjusted, the worn discharge beads are taken out, and new discharge beads are replaced, and steps S2 to S5 are repeated.

[0025] Compared with the prior art, the present invention has achieved the following technical effects:

[0026] The present invention provides a rotary ball array electrode for electrospark machining and an array feature machining method. The discharge ball is used as the main area for electrospark machining, a support plate and its connecting assembly are constructed to limit the discharge ball, and a ball squeezing assembly and its clamping mechanism are established to enable the discharge ball to rotate. This can achieve full and efficient utilization of the discharge ball machining surface and realize efficient, high-quality batch manufacturing of array features. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 Schematic diagram of the three-dimensional structure of the rotating ball array electrode for electrospark machining in Example 1;

[0029] Figure 2 This is a schematic diagram of the main structure of the rotary ball array electrode for electrospark machining in Example 1;

[0030] Figure 3 It is a side view schematic diagram of the present invention in which the ball pressure plate rotates to drive the discharge ball to rotate;

[0031] Figure 4 This is a top view schematic diagram of the discharge ball rotating on the support plate of the present invention;

[0032] Figure 5 Schematic diagram of the workpiece surface array feature processing process of the present invention;

[0033] Figure 6 This is a schematic diagram of the updated discharge area of ​​the discharge ball of the present invention;

[0034] Figure 7 Schematic diagram of the three-dimensional structure of the rotating ball array electrode for electrospark machining in Example 2;

[0035] Figure 8 This is a schematic diagram of the main structure of the rotary ball array electrode for electrospark machining in Example 2;

[0036] In the figure: 1-clamping spindle, 2-rotating disk, 3-clamping mechanism, 4-ball extrusion assembly, 5-clamping limit plate, 6-ball pressure plate, 7-lifting support assembly, 8-column, 9-lifting support bolt, 10-lifting control nut, 11-compression spring, 12-support plate, 13-connecting assembly, 14-support ball hole, 15-discharge ball, 16-rotating chuck, 17-clamping nut, 18-fixing bolt, 19-transition bearing ring, 20-bearing bolt, 21-friction block, 22-workpiece. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] The purpose of the present invention is to provide a rotary ball array electrode for electrospark machining and an array feature machining method to solve the problems existing in the prior art and to achieve efficient and high-quality batch machining of array features.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] like Figures 1-6As shown, this embodiment provides a rotating ball array electrode for electrospark machining, including a clamping spindle 1, the lower end of the clamping spindle 1 is rotatably connected to a rotating disk 2, the lower end of the rotating disk 2 is fixedly connected to a clamping mechanism 3, the lower end of the clamping mechanism 3 is clamped and fixedly connected to a ball squeezing assembly 4, the ball squeezing assembly 4 includes a clamping limit plate 5, a ball pressure plate 6 and a lifting support assembly 7, the clamping limit plate 5 is clamped and fixed to the lower end of the clamping mechanism 3 by a column 8, the ball pressure plate 6 is connected to the bottom of the clamping limit plate 5 through a plurality of lifting support assemblies 7, the lifting support assembly 7 includes a lifting support bolt 9, a lifting control nut 10 and a compression spring 11, the lifting support bolt 9 passes through the ball pressure plate 6 and the clamping limit plate 5 from the bottom in sequence. The through hole is threadedly connected to the lifting control nut 10, and the compression spring 11 is sleeved on the outside of the lifting support bolt 9. The compression spring 11 is in a contracted state and its two ends are respectively against the ball pressure plate 6 and the clamping limit plate 5. A support plate 12 is provided under the ball pressure plate 6. The support plate 12 is fixedly connected to the clamping spindle 1 through a connecting assembly 13. A plurality of supporting ball holes 14 distributed in an array are provided on the support plate 12. Each supporting ball hole 14 is used to place and support the discharge ball 15. The discharge ball 15 protrudes from the lower surface of the support plate 12. The rotation of the rotating disk 2 can drive the ball pressure plate 6 to rotate around the vertical axis. The ball pressure plate 6 rotates and squeezes each discharge ball 15, so that each discharge ball 15 rotates in the same horizontal plane.

[0042] The clamping spring 11, lifting support bolt 9 and lifting control nut 10 between the clamping limit plate 5 and the ball pressure plate 6 can effectively limit and rotate the discharge ball 15, making the processing process automated and controllable. The lifting control nut 10 can realize the leveling and pressure control of the ball pressure plate 6. The clamping spring 11 can ensure the pressure of the ball pressure plate 6 on the discharge ball 15, and can limit the discharge ball 15 and rotate the discharge ball 15 under friction. The introduction of the discharge ball 15 makes the array feature electrospark forming processing a standardized production process, and the standardized production of the discharge ball 15 makes its morphology extremely consistent, which will greatly improve the consistency of the processed surface morphology compared with traditional forming electrodes, and its replaceability can ensure rapid mass production.

[0043] In this embodiment, the clamping mechanism 3 includes a rotating chuck 16 and a clamping nut 17. The rotating chuck 16 is fixedly connected to the lower end of the rotating disk 2, and the clamping nut 17 is fixedly connected to the lower end of the rotating chuck 16. The column 8 is clamped and fixed within the clamping nut 17. The rotating chuck 16 is a standard module and is used in conjunction with the clamping nut 17 to clamp the column 8 below.

[0044] In this embodiment, the connecting assembly 13 includes a fixing bolt 18, a transition load-bearing ring 19, and a load-bearing bolt 20. The transition load-bearing ring 19 is sleeved over the clamping nut 17. The transition load-bearing ring 19 is connected to the clamping spindle 1 via a plurality of fixing bolts 18, and is connected to the support plate 12 via a plurality of load-bearing bolts 20. The fixing bolts 18, transition load-bearing ring 19, and load-bearing bolts 20 securely connect the support plate 12 to the clamping spindle 1, thereby securing the position of the support plate 12. The structure is simple and easy to adjust and install.

[0045] In this embodiment, the fixing bolts 18 are evenly connected to the transition load-bearing ring 19 along the circumference, and the load-bearing bolts 20 are evenly connected to the transition load-bearing ring 19 along the circumference and staggered with the fixing bolts 18. This makes the structure more stable and the force more uniform.

[0046] In this embodiment, support plate 12 is a square support plate with four load-bearing bolts 20, one at each corner of the square support plate. Four fixing bolts 18 are provided, and these bolts 18 and load-bearing bolts 20 are alternately connected to transition load-bearing rings 19 at 45° intervals to ensure structural stability.

[0047] In this embodiment, four lifting support assemblies 7 are provided, and each lifting support assembly 7 is evenly connected to the ball pressure plate 6 along the circumferential direction, so that the ball pressure plate 6 can be adjusted more conveniently.

[0048] Example 2

[0049] like Figure 7-Figure 8 As shown, this embodiment provides a rotating ball array electrode for electrospark machining. The difference from the first embodiment is that the connecting component 13 includes load-bearing bolts 20, and the support plate 12 is directly connected to the clamping spindle 1 through multiple load-bearing bolts 20, making the structure of the connecting component 13 simpler.

[0050] Example 3

[0051] A method for machining array features on a workpiece surface, using the rotary ball array electrode for electrospark machining described in the first or second embodiment, comprises the following steps:

[0052] S1: Place a discharge ball 15 into each supporting ball hole 14 on the supporting plate 12;

[0053] S2: Adjust the lifting control nut 10 in multiple positions so that the ball pressure plate 6 can press each discharge ball 15 and level the ball pressure plate 6;

[0054] S3: Turn on the rotation function. The rotating disk 2 rotates to drive the ball pressure plate 6 to rotate around the vertical axis. The pressure of the ball pressure plate 6 on the discharge balls 15 and the friction coefficient of the friction pair are set. The ball pressure plate 6 rotates and, under the action of friction, causes the discharge balls 15 to rotate in the same horizontal plane.

[0055] S4: Starting the EDM program, and realizing a one-time multi-point forming process of the array feature by setting the distance between the discharge ball 15 and the workpiece 22;

[0056] S5: Move the clamping spindle 1, set the single movement distance of the clamping spindle 1 according to the distance between the discharge balls 15, perform sequential processing according to the program, and form a large-area curved array feature on the surface of the workpiece 22.

[0057] Among them, the rotating disk 2 can be connected to a powered wire to achieve access to one pole of the power supply, and the workbench is connected to the other pole of the power supply. The workpiece 22 is placed on the workbench and is in conductive contact with the workbench, thereby realizing electric spark machining between the discharge ball 15 and the workpiece 22.

[0058] In step S2, the pressure between each discharge ball 15 and the ball pressure plate 6 is detected by a pressure sensor, and the lifting control nut 10 is adjusted to make the detected pressure values ​​equal to achieve leveling of the ball pressure plate 6.

[0059] During the machining process, due to the inevitability of EDM loss, after the discharge ball 15 rotates and loses to the loss limit value, that is, the electrode loss limit when its machining feature morphology no longer meets the requirements, the clamping spindle 1 is moved to the specified friction block 21 area, and the lifting control nut 10 is adjusted to move the ball pressure plate 6 upward without squeezing the discharge ball 15, so that each discharge ball 15 is in a free state, and is fed vertically downward a specified distance, so that a friction pair is formed between the lower surface of each discharge ball 15 and the friction block 21 to achieve the update of the discharge area. The discharge area refers to the area on the electrode where discharge behavior occurs after each discharge. After the discharge area is updated, the clamping spindle 1 is moved back to the machining area to continue machining.

[0060] When all the processed surfaces of the discharge beads 15 have been worn to the limit, the lifting control nut 10 is adjusted to remove the worn discharge beads 15, replace them with new ones, and repeat steps S2 to S5. A spherical surface can accommodate many flattened areas after discharge. The processed surfaces of the discharge beads 15 have been worn to the limit when all the flattened areas on the discharge beads 15 have been worn to the limit.

[0061] The assembly design of the rotary ball array electrode for EDM proposed in the present invention reduces the manufacturing cost of the integrally formed array electrode, and rapid processing of array features can be achieved by simply changing the position and batch of discharge balls.

[0062] The rotation of the rotating disk 2 connected to the clamping spindle of the forming spark machine drives the ball pressure plate 6 to rotate, and then drives the discharge ball 15 to rotate, and it can realize multiple functions according to needs. When the ball pressure plate 6 rotates, the discharge ball 15 can realize a function similar to discharge milling. When the ball pressure plate 6 does not rotate, the discharge ball 15 does not move, which can ensure single-point processing, that is, the electrode will be processed multiple times at the same position. Either way, the discharge area can be greatly improved.

[0063] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A rotary ball array electrode for electrospark machining, characterized in that: It includes a clamping spindle, the lower end of the clamping spindle is rotatably connected to a rotating disk, the lower end of the rotating disk is fixedly connected to a clamping mechanism, the lower end of the clamping mechanism is clamped and fixedly connected to a ball extrusion assembly, the ball extrusion assembly includes a clamping limit plate, a ball pressure plate and a lifting support assembly, the clamping limit plate is clamped and fixed to the lower end of the clamping mechanism through a column, the ball pressure plate is connected to the bottom of the clamping limit plate through a plurality of lifting support assemblies, the lifting support assembly includes a lifting support bolt, a lifting control nut and a compression spring, the lifting support bolt passes through the through holes on the ball pressure plate and the clamping limit plate from the bottom in sequence and then engages with the lifting control nut The cam is connected with the lifting and lowering members, and the cam is connected to the lifting and lowering members by a threaded connection. The cam is in a retracted state and both ends are respectively against the ball pressure plate and the clamping limit plate. A support plate is provided under the ball pressure plate, and the support plate is fixedly connected to the clamping spindle through a connecting assembly. A plurality of supporting ball holes distributed in an array are provided on the support plate, and each supporting ball hole is used to place and support the discharge ball. The discharge ball protrudes from the lower surface of the support plate. The rotation of the rotating disk can drive the ball pressure plate to rotate around the vertical axis. The ball pressure plate rotates and squeezes each discharge ball, so that each discharge ball rotates in the same horizontal plane.

2. The rotary ball array electrode for electric discharge machining according to claim 1, characterized in that: The clamping mechanism includes a rotating chuck and a clamping nut. The rotating chuck is fixedly connected to the lower end of the rotating disk. The clamping nut is fixedly connected to the lower end of the rotating chuck. The column is clamped and fixed in the clamping nut.

3. The rotary ball array electrode for electric discharge machining according to claim 2, characterized in that: The connecting assembly includes a fixing bolt, a transition load-bearing ring and a load-bearing bolt. The transition load-bearing ring is sleeved outside the clamping nut. The transition load-bearing ring is connected to the clamping spindle through a plurality of the fixing bolts and is connected to the support plate through a plurality of the load-bearing bolts.

4. The rotary ball array electrode for electric discharge machining according to claim 3, characterized in that: The fixing bolts are evenly connected to the transition load-bearing ring along the circumferential direction, and the load-bearing bolts are evenly connected to the transition load-bearing ring along the circumferential direction and are staggered with the fixing bolts.

5. The rotary ball array electrode for electric discharge machining according to claim 4, characterized in that: The support plate is a square support plate, and four load-bearing bolts are provided, with each of the four corners of the square support plate being connected with a load-bearing bolt.

6. The rotary ball array electrode for electric discharge machining according to claim 1, characterized in that: The lifting support components are provided in four, and each lifting support component is evenly connected to the ball pressure plate along the circumferential direction.

7. A method for processing array features on a workpiece surface, characterized in that: The rotary ball array electrode for electrospark machining according to any one of claims 1 to 6 comprises the following steps: S1: placing one discharge ball into each of the support ball holes on the support plate; S2: Adjusting the lifting control nut at multiple positions so that the ball pressure plate can press each of the discharge balls and level the ball pressure plate; S3: Turn on the rotation function. The rotation of the rotating disk drives the ball pressure plate to rotate around the vertical axis. The pressure of the ball pressure plate on the discharge balls and the friction coefficient of the friction pair are set. The ball pressure plate rotates and, under the action of friction force, causes the discharge balls to rotate in the same horizontal plane. S4: starting the EDM program, and realizing a one-time multi-point forming process of the array feature by setting the distance between the discharge ball and the workpiece; S5: Move the clamping spindle, set the single movement distance of the clamping spindle according to the distance between the discharge balls, perform sequential processing according to the program, and form large-area curved surface array features on the surface of the workpiece.

8. The method for machining array features on a workpiece surface according to claim 7, wherein: In step S2, the pressure between each discharge ball and the ball pressure plate is detected by a pressure sensor, and the lifting control nut is adjusted to make the detected pressure values ​​equal to achieve leveling of the ball pressure plate.

9. The method for machining array features on a workpiece surface according to claim 7, wherein: During the processing, after the rotation loss of the discharge ball reaches the loss limit value, the clamping spindle is moved to the specified friction block area, the lifting control nut is adjusted so that each discharge ball is in a free state, and the clamping spindle is fed vertically downward by a specified distance, driving the support plate to move downward synchronously, so that a friction pair is formed between the lower surface of each discharge ball and the friction block to achieve the update of the discharge area. After the discharge area is updated, the clamping spindle is moved back to the processing area to continue processing.

10. The method for machining array features on a workpiece surface according to claim 9, wherein: When the processed surfaces of the discharge balls are all worn out to the limit, the lifting control nut is adjusted to remove all the worn discharge balls, replace them with new ones, and repeat steps S2 to S5.

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