A wheel-and-ring type magnetorheological polishing device based on electromagnetic principle

Abstract

The application discloses a wheel-ring type magnetorheological polishing device based on electromagnetic principle, which comprises a transmission shaft and an excitation assembly with a coil, the end of the transmission shaft is provided with an annular polishing wheel, the coil is sleeved on the outside of the transmission shaft, and one side of the coil is provided with a magnetic isolation assembly for forming a working area and a non-working area of the annular polishing wheel, so that the contact area of the polishing belt with a workpiece is increased, and the machining efficiency is improved; the magnetic isolation assembly restrains and isolates the magnetic field of the non-machining area, guarantees the magnetic field intensity in the machining area, prevents the magnetic field of the non-machining area from interfering with the magnetic field of the machining area, effectively prevents the magnetic field from affecting the circulation of the magnetorheological fluid in the nozzle and the recycler, improves the gradient magnetic field intensity of the machining area, and improves the machining stability.

Description

Technical Field

[0001] This invention relates to magnetorheological polishing technology, specifically to a ring-type magnetorheological polishing device based on electromagnetic principles. Background Technology

[0002] With the modernization of society and the advancement of science and technology, the application range of optical components is becoming increasingly wide, and the performance indicators of optical components are also becoming increasingly demanding. This poses continuous challenges to the manufacturing technology of optical components, as traditional optical manufacturing techniques are no longer applicable, leading to the emergence of various new polishing technologies. Magnetorheological polishing technology has the advantages of wide application range, small subsurface damage, high processing accuracy, and high surface convergence rate, and has broad development prospects. Currently, wheel-type magnetorheological polishing is widely used, but it has obvious polishing texture, small polishing spots, low processing efficiency, and a constant magnetic field strength. In order to better achieve high-efficiency, high-precision, and high surface quality processing of optical mirrors, new magnetorheological polishing technologies are constantly emerging, such as clustered magnetorheological polishing, magnetic composite fluid magnetorheological polishing, and chemical mechanical magnetorheological polishing. Most of these technologies improve material removal efficiency by increasing the contact area between the polishing mold and the workpiece. However, existing technologies still have problems such as the magnetorheological fluid not being recyclable, the magnetic field strength being unchangeable, the gradient magnetic field not being constrained and shielded, and the magnetic field strength not being guaranteed, making it difficult to guarantee the stability of material removal efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a ring-type magnetorheological polishing device based on electromagnetic principles, which aims to achieve recyclable magnetorheological fluid, variable magnetic field strength, and magnetic isolation treatment of gradient magnetic field to ensure magnetic field strength, thereby achieving high and stable material removal efficiency.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A ring-type magnetorheological polishing device based on electromagnetic principles includes a drive shaft and an excitation assembly with a coil. The end of the drive shaft is provided with an annular polishing wheel, the coil is sleeved on the outside of the drive shaft, and one side of the coil is provided with a magnetic shielding assembly for forming a working area and a non-working area of ​​the annular polishing wheel.

[0006] As a further improvement to the above technical solution:

[0007] The excitation assembly also includes an iron core, which is an open annular structure sleeved on the outside of the transmission shaft and arranged coaxially with the annular polishing wheel; the iron core is fixed below the fixed connecting plate by a connector and a coil groove is provided on the inner side of the iron core, and the coil is installed in the coil groove.

[0008] A cooling assembly is installed around the coil.

[0009] The iron core is provided with uniformly arranged arc-shaped inner and outer magnetic poles. The surface of the annular polishing wheel corresponding to the tips of the inner and outer magnetic poles is the processing area; the surface of the annular polishing wheel corresponding to the opening area is the non-processing area.

[0010] The annular polishing wheel has a groove near the excitation assembly, and the tips of the inner and outer magnetic poles form a slit in the groove of the annular polishing wheel.

[0011] The magnetic shielding assembly includes a magnetic shielding plate and a magnetic shielding cover. The magnetic shielding cover has an annular opening structure and an annular groove inside for wrapping the coil in the non-working area. A magnetic shielding plate is provided above the magnetic shielding cover. The magnetic shielding plate has a circular structure, is installed above the iron core and is connected to the fixed connecting plate through a connector. An air gap is left between the magnetic shielding plate and the magnetic shielding cover.

[0012] The excitation component and the magnetic isolation component are equipped with protective sleeves on their outer sides.

[0013] The fixed connecting plate is a circular structure located above the magnetic shielding plate. A bearing is installed between the inner side of the fixed connecting plate and the transmission shaft to fix the connecting plate and the machine tool body, so that the fixed connecting plate and the machine tool body remain relatively stationary during the operation of the transmission shaft.

[0014] The fixed connecting plate is equipped with an inverted C-shaped nozzle frame and a recovery frame. The nozzle frame and the recovery frame are symmetrically distributed on both sides of the non-working area of ​​the annular polishing wheel. The nozzle frame and the recovery frame wrap around the annular polishing wheel from the fixed connecting plate to the lower end of the annular polishing wheel, which is directly opposite the annular polishing wheel, so as to realize the spraying and recovery of magnetorheological fluid in the non-processing area of ​​the annular polishing wheel by the nozzle and the recovery device.

[0015] A processing platform is provided below the annular polishing wheel, and the processing platform includes a processing platform base and a raising platform.

[0016] Compared with the prior art, the advantages of the present invention mainly include: The present invention includes a drive shaft and an excitation assembly with a coil. The end of the drive shaft is provided with an annular polishing wheel. The coil is sleeved on the outside of the drive shaft, and one side of the coil is provided with a magnetic shielding assembly for forming a working area and a non-working area of ​​the annular polishing wheel. This increases the contact area between the polishing ribbon and the workpiece and improves the processing efficiency. The magnetic shielding assembly constrains and isolates the magnetic field in the non-processing area, ensuring the magnetic field strength in the processing area and preventing the magnetic field in the non-processing area from interfering with the magnetic field in the processing area. This effectively prevents the magnetic field from affecting the circulation of the magnetorheological fluid in the nozzle and the recoverer, increases the gradient magnetic field strength in the processing area, and improves the processing stability. Attached Figure Description

[0017] Figure 1This is a perspective view of an embodiment of the present invention.

[0018] Figure 2 This is a perspective view of the component above the fixed connecting plate that mates with the drive shaft.

[0019] Figure 3 This is a perspective view of the excitation device excluding the coil and cooling device in an embodiment of the present invention.

[0020] Figure 4 This is a three-dimensional view of the complete excitation device according to an embodiment of the present invention.

[0021] Figure 5 This is a perspective view of the magnetic shielding device according to an embodiment of the present invention.

[0022] Figure 6 This is a side view of the magnetic shielding device according to an embodiment of the present invention.

[0023] Figure 7 This is a side view of the excitation device and the magnetic isolation device during assembly according to an embodiment of the present invention.

[0024] Figure 8 for Figure 7 Cross-sectional view.

[0025] Figure 9 This is a schematic diagram illustrating the processing of an embodiment of the present invention.

[0026] Legend: 1. Excitation device; 11. Iron core; 12. Outer magnetic pole; 13. Inner magnetic pole; 14. Coil; 15. Cooling device; 16. Coil slot; 2. Magnetic shielding device; 21. Magnetic shielding plate; 22. Magnetic shielding cover; 23. Air gap; 3. Drive shaft; 31. Bushing; 32. Angular contact ball bearing; 33. Fastening nut; 34. End cover; 35. Pulley; 36. Polishing wheel connecting plate; 4. Fixed connecting plate; 41. Spray nozzle frame; 42. Recycling frame; 43. Groove; 5. Protective sleeve; 6. Machine tool connecting plate; 7. Annular polishing wheel; 8. Machining platform; 81. Machining platform base; 82. Elevating platform; 83. Workpiece. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] like Figures 1-9 The embodiment shown illustrates a ring-type magnetorheological polishing device based on electromagnetic principles, comprising: a drive shaft 3 and an excitation assembly 1 with a coil 14. The end of the drive shaft 3 is equipped with an annular polishing wheel 7. The coil 14 is sleeved on the outside of the drive shaft 3, and one side of the coil 14 has a magnetic shielding assembly 2 for forming a working area and a non-working area on the annular polishing wheel 7. The end of the drive shaft 3 is equipped with a polishing wheel connecting plate 36. The annular polishing wheel 7 and the polishing wheel connecting plate 36 are fixed by a connector, enabling the drive shaft 3 to drive the annular polishing wheel 7 to rotate. When the coil 14 of the excitation assembly 1 is energized, it generates a gradient magnetic field in the processing area. The magnetic shielding assembly constrains the magnetic field generated by the coil, preventing the magnetic field in the non-processing area from interfering with the magnetic field in the processing area, ensuring the magnetic field strength in the processing area, and forming a good gradient magnetic field on the surface of the annular polishing wheel. When the magnetorheological fluid flows through the processing area, it transforms into a Bingham fluid state similar to a solid, processing the workpiece; when it flows through the non-processing area, the magnetorheological fluid returns to a flowable liquid state, ensuring the recycling and circulation of the magnetorheological fluid. The end of the drive shaft 3 is provided with a polishing wheel connecting plate 36. The annular polishing wheel 7 is fixed to the polishing wheel connecting plate 36 by a connector, so that the drive shaft 3 can drive the annular polishing wheel 7 to rotate.

[0030] like Figure 3 , Figure 4 As shown, in this embodiment, the excitation assembly 1 also includes an iron core 11. The iron core 11 is an open annular structure sleeved on the outside of the transmission shaft 3 and arranged coaxially with the annular polishing wheel 7. The iron core 11 is fixed below the fixed connecting plate 4 by a connector, and a coil groove 16 is provided on the inner side of the iron core 11. The coil 14 is installed in the coil groove 16. In this embodiment, the current in the coil 14 can be changed according to the processing requirements, thereby changing the magnetic field strength. The magnetic field generated by the energized coil 14 is guided to the outer magnetic pole 12 and the inner magnetic pole 13 through the iron core 11.

[0031] like Figure 8As shown, in this embodiment, a cooling component 15 is installed around the coil 14. The cooling component 15 is filled with coolant at a certain flow rate to prevent the coil 14 from overheating and causing the enameled wire to melt, thereby reducing the ambient temperature of the magnetorheological fluid and improving the stability of the magnetorheological fluid operation, thus enabling the device to operate for a long time and operate stably.

[0032] like Figure 8 As shown, in this embodiment, the iron core 11 is provided with an inner magnetic pole 13 and an outer magnetic pole 12 with a uniformly arranged arc structure below it. The surface of the annular polishing wheel 7 corresponding to the tip of the inner magnetic pole 13 and the outer magnetic pole 12 is the processing area; the surface of the annular polishing wheel 7 corresponding to the opening area is the non-processing area. Undoubtedly, the opening angle of the iron core 11 with the opening, the inner magnetic pole 13 and the outer magnetic pole 12 can be adjusted according to the processing needs. In this embodiment, the preferred opening area central angle is 180°.

[0033] like Figure 8 As shown, in this embodiment, the annular polishing wheel 7 has a groove near the excitation assembly 1. The tips of the inner magnetic pole 13 and the outer magnetic pole 12 form a slit in the groove of the annular polishing wheel 7. A gradient magnetic field is generated at the slit between the outer magnetic pole 12 and the inner magnetic pole 13. The gradient magnetic field exists only in the processing area of ​​the annular polishing wheel 7. In this embodiment, both the excitation assembly 1 and the magnetic isolation assembly 2 are arranged in the groove of the annular polishing wheel 7.

[0034] like Figure 1 As shown, in this embodiment, the machine tool is connected to the machine tool via a machine tool connecting plate 6. The drive pulley 35 rotates, driving the transmission shaft 3 to rotate. The transmission shaft 3 drives the annular polishing wheel 7 to rotate, and the workpiece is polished using the processing area of ​​the annular polishing wheel 7.

[0035] like Figures 5-8 As shown, in this embodiment, the magnetic shielding assembly 2 includes a magnetic shielding plate 21 and a magnetic shielding cover 22. The magnetic shielding cover 22 has an annular opening structure and an annular groove inside for enclosing the coil 14 in the non-working area. The magnetic shielding plate 21 is positioned above the magnetic shielding cover 22. The magnetic shielding plate 21 has a circular structure, is installed above the iron core 11, and is connected to the fixed connecting plate 4 via a connector. An air gap 23 is left between the magnetic shielding plate 21 and the magnetic shielding cover 22 to prevent direct contact between the magnetic shielding plate 21 and the iron core 11, which could affect the magnetic field circuit of the processing area. The magnetic shielding plate 21 shields the magnetic field generated by the excitation device 1, preventing magnetic leakage and ensuring the magnetic field strength of the processing area. Both the magnetic shielding plate 21 and the magnetic shielding cover 22 are made of magnetically conductive material.

[0036] like Figure 8As shown, a protective sleeve 5 is installed on the outside of the excitation assembly 1 and the magnetic isolation assembly 2. The protective sleeve 5 is tightly attached to the fixed connecting plate 4 and the iron core 11, and a gap is left between it and the magnetic isolation plate 21 to prevent the magnetic isolation plate 21 from interfering with the magnetic field circuit on the iron core 11. The protective sleeve 5 prevents iron powder in the magnetorheological fluid from entering the device through the magnetic field, keeps the inside of the device clean, and improves the stability of the device operation. The protective sleeve 5 is made of non-magnetic material.

[0037] like Figure 6 , Figure 8 As shown, in this embodiment, the fixed connecting plate 4 is a circular structure located above the magnetic shielding plate 21. A bearing is installed between the inner side of the fixed connecting plate 4 and the transmission shaft 3 to fix the connecting plate 4 and the machine tool body, so that the fixed connecting plate 4 and the machine tool body remain relatively stationary during the operation of the transmission shaft 3. A load-bearing bearing is installed above the fixed connecting plate 4, and a fastening nut 33 is installed above the bearing to reinforce it. An end cover 34 is installed on the outside of the bearing and the fastening nut 33 to protect them, and a fastening nut 33 is installed above the end cover 34 to reinforce it. The bearing includes a sleeve shaft 31 and an angular contact bearing 32.

[0038] like Figure 1 , Figure 9 As shown, in this embodiment, an inverted C-shaped nozzle frame 41 and a recovery frame 42 are installed on the fixed connecting plate 4. The nozzle frame 41 and the recovery frame 42 are symmetrically distributed on both sides of the non-working area of ​​the annular polishing wheel 7. The nozzle frame 41 and the recovery frame 42 extend from the fixed connecting plate 4, wrap around the annular polishing wheel 7, and extend to the lower end of the annular polishing wheel 7, directly opposite the annular polishing wheel 7. This allows the nozzle and the recovery device to spray and recover the magnetorheological fluid in the non-processing area of ​​the annular polishing wheel 7, thereby achieving the circulation of the magnetorheological fluid. The magnetic shield 22 isolates the magnetic field in the non-processing area to prevent it from interfering with the magnetic field in the processing area, thus avoiding the magnetorheological effect of the magnetorheological fluid on the nozzle frame 41 and the recovery frame 42, which would affect the spraying and recovery of the magnetorheological fluid.

[0039] like Figures 1-8 As shown, in this embodiment, when processing the workpiece, the drive device drives the pulley 35 to rotate, the pulley 35 drives the transmission shaft 3 to rotate, and the transmission shaft 3 drives the annular polishing wheel 7 to rotate. The nozzle frame 41 and the recovery frame 42 are placed below the non-processing area of ​​the annular polishing wheel 7. When the magnetorheological fluid is sprayed from the nozzle on the nozzle frame 41 and flows through the processing area of ​​the annular polishing wheel 7, the magnetorheological effect occurs, and the magnetorheological fluid turns into a Bingham body state similar to a solid, and processes the workpiece 83. When the magnetorheological fluid flows out of the processing area, due to the weakening of the magnetic field strength, the magnetorheological fluid returns to a flowable liquid state. At the same time, the recovery device on the recovery frame 42 recovers the magnetorheological fluid.

[0040] like Figure 9As shown, in this embodiment, a processing platform 8 is provided below the annular polishing wheel 7. The processing platform 8 includes a processing platform base 81 and a lifting platform 82. The lifting platform 82 is placed between the processing platform base 81 and the workpiece 83 to prevent interference between the nozzle frame 41, the recovery frame 42 and the processing platform 81. The lifting platform of a certain height is installed on the processing platform, and the workpiece to be processed is placed on the lifting platform to increase the distance between the annular polishing wheel and the processing platform, thus reserving working space for the nozzle and the recovery frame.

[0041] In summary, the ring-type magnetorheological polishing device based on electromagnetic principles in this embodiment forms a processing area by generating a gradient magnetic field in a 180° region on the lower surface of the ring polishing wheel 7 using coil 14. This increases the contact area between the magnetorheological ribbon and the workpiece 83, improving processing efficiency. Furthermore, the current in coil 14 can be adjusted to change the magnetic field strength according to processing requirements. A magnetic shielding device 2 is also provided to confine the magnetic field generated by coil 14, improving the magnetic field strength and stability of the processing area and preventing interference from the magnetic field in the non-processing area. A protective sleeve 5 is provided around the iron core 11 to prevent iron powder in the magnetorheological fluid from entering the device with the magnetic field, serving a cleaning and protective function and improving the operational stability of the device.

[0042] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A ring-type magnetorheological polishing device based on electromagnetic principles, characterized in that, The device includes a drive shaft (3) and an excitation assembly (1) with a coil (14). The end of the drive shaft (3) is provided with an annular polishing wheel (7). The coil (14) is sleeved on the outside of the drive shaft (3). One side of the coil (14) is provided with a magnetic shielding assembly (2) for forming a processing area and a non-processing area with the annular polishing wheel (7). This allows the coil (14) of the excitation assembly (1) to generate a gradient magnetic field in the processing area after being energized. The magnetic shielding assembly (2) includes a magnetic shielding plate (21) and a magnetic shielding cover (22). The magnetic shielding cover (22) is an annular opening structure with an annular groove inside for wrapping the coil (14) in the non-processing area. The magnetic shielding cover (22) is provided with a magnetic shielding plate (21) above it. The magnetic shielding plate (21) is a circular structure, installed above the iron core (11) and connected to the fixed connecting plate (4) through a connector. An air gap (23) is left between the magnetic shielding plate (21) and the magnetic shielding cover (22).

2. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 1, characterized in that, The excitation assembly (1) also includes an iron core (11), which is an open annular structure sleeved on the outside of the transmission shaft (3) and arranged coaxially with the annular polishing wheel (7); the iron core (11) is fixed below the fixed connecting plate (4) by a connector and a coil groove (16) is provided on the inner side of the iron core (11), and the coil (14) is installed in the coil groove (16).

3. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 2, characterized in that, A cooling assembly (15) is installed around the coil (14).

4. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 2, characterized in that, The iron core (11) is provided with an inner magnetic pole (13) and an outer magnetic pole (12) of a uniformly arranged arc structure below it. The surface of the annular polishing wheel (7) corresponding to the tip of the inner magnetic pole (13) and the outer magnetic pole (12) is the processing area; the surface of the annular polishing wheel (7) corresponding to the opening area of ​​the open annular structure is the non-processing area.

5. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 4, characterized in that, The annular polishing wheel (7) has a groove near the excitation assembly (1), and the tips of the inner magnetic pole (13) and the outer magnetic pole (12) form a slit in the groove of the annular polishing wheel (7).

6. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 1, characterized in that, The excitation assembly (1) and the magnetic isolation assembly (2) are equipped with protective sleeves (5) on their outer sides.

7. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 5, characterized in that, The fixed connecting plate (4) is a circular structure located above the magnetic shielding plate (21). A bearing is installed between the inner side of the fixed connecting plate (4) and the transmission shaft (3) to fix the connecting plate (4) and the machine tool body, so that the fixed connecting plate (4) and the machine tool body remain relatively stationary during the operation of the transmission shaft (3).

8. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 7, characterized in that, The fixed connecting plate (4) is equipped with an inverted C-shaped nozzle frame (41) and a recovery frame (42). The nozzle frame (41) and the recovery frame (42) are symmetrically distributed on both sides of the non-processing area of ​​the annular polishing wheel (7). The nozzle frame (41) and the recovery frame (42) wrap around the annular polishing wheel (7) from the fixed connecting plate (4) to the lower end of the annular polishing wheel (7) directly opposite the annular polishing wheel (7), so that the nozzle and the recovery device can spray and recover magnetorheological fluid in the non-processing area of ​​the annular polishing wheel (7).

9. The ring-type magnetorheological polishing device based on electromagnetic principles according to claim 1, characterized in that, The annular polishing wheel (7) is provided with a processing platform (8) below it. The processing platform (8) includes a processing platform base (81) and a raising platform (82).

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