Magnetic field array polishing apparatus

Abstract

The application relates to the technical field of polishing equipment and discloses a magnetic field array polishing device which comprises an array carrier, a rotating shaft and an outer sleeve. Two rows of edge magnet groups and one row of middle magnet groups are arranged on the side surface of the array carrier; one end of the rotating shaft is inserted into the bottom of the array carrier, and the other end extends out of the array carrier; the rotating shaft is driven by an output source to rotate the array carrier; and the outer sleeve is arranged on the outer side of the array carrier. The magnetic field of each N-pole of the polishing device is obviously brush-shaped, the brush-shaped magnetic field of the multiple N-poles is continuously distributed in an S-shaped mode from the side surface of the array carrier, the number and intensity of the magnetic field passing through any 30mm-long line segment on the outer side of the array carrier parallel to the array carrier axial direction are consistent when the array rotates one round, the magnetorheological polishing is more uniform and sufficient, and the efficiency and capacity of the magnetorheological polishing are improved.

Description

Technical Field

[0001] This invention relates to the field of polishing equipment technology, and more specifically, to a magnetic field array polishing device. Background Technology

[0002] Magnetorheological fluids consist of magnetizable micron-sized iron particles, a non-magnetizable matrix or carrier fluid, and additives to combat sedimentation and agglomeration. The rheological properties of magnetorheological fluids change with a magnetic field; they flow freely in the absence of a magnetic field, but when a magnetic field is applied, they rapidly transform into a solid-like structure within milliseconds. Magnetorheological polishing slurries are obtained by adding abrasives to a magnetorheological fluid and thoroughly stirring.

[0003] Magnetorheological polishing technology is a technique that uses magnetorheological polishing fluid to polish objects. It has the characteristics of high surface accuracy, low surface roughness, controllable processing, small subsurface damage depth, and no new damage generated during processing. It is often used in ultra-precision machining fields with high precision requirements, the most common of which is the surface processing of optical parts.

[0004] Figure 1 The figure shows the changes in carbonyl iron powder particles (CIPs) and abrasive particles in a magnetorheological polishing slurry with and without a magnetic field. As can be seen from the figure, without a magnetic field, the carbonyl iron powder particles and abrasive particles are randomly mixed in the carrier fluid, allowing the fluid to flow freely. When a magnetic field is applied, the carbonyl iron powder particles form a chain-like arrangement along the direction of the magnetic field, randomly trapping abrasive particles between them. This results in a structure where the carbonyl iron powder particles and abrasive particles form a chain-like arrangement. Figure 1 (b) shows a linear sandwich chain structure. When a magnetic field and shear strain are applied simultaneously, the shear strain forces the linear sandwich chain structure to deviate towards the shear strain direction. The interparticle gaps inside the structure increase, but it still remains a linear chain. This causes some abrasive particles to detach from the linear sandwich chain structure in the shear strain direction. A large number of free abrasive particles come into contact with the surface of the object being polished under the combined effect of the shear strain applied to the linear sandwich chain structure and the magnetic tendency of the chain structure to return to its original direction, thus shearing the surface of the object and achieving flexible polishing. This is the microscopic mechanism of magnetorheological polishing. As can be seen from the above, the magnetorheological polishing process is highly dependent on the external magnetic field. Theoretically, the stronger the external magnetic field, the higher the polishing efficiency and the stronger the polishing ability in the magnetorheological polishing process.

[0005] like Figure 2As shown in the paper, Zhang Xianglei, Chen Zhuojie, et al., published a study on chemical magnetorheological polishing of medical titanium alloys using a Hellbeck magnetic field array [J]. The Journal of Hunan University (Natural Science Edition) discloses a polishing device comprising an array carrier, a shaft, magnets, and a copper sleeve. The manufacturing method involves hollowing out the array carrier, embedding magnets in designated positions according to the Hellbeck array (a magnet array that concentrates most of the magnet's energy on one side to form a high-energy magnetic field, commonly used in CT scanners, magnetic levitation, and other industries requiring high-energy magnetic fields), then fitting the copper sleeve onto the surface of the array carrier, and finally installing the shaft. The high-energy magnetic field generated by the Hellbeck array makes the magnetic flux structure in the magnetorheological polishing fluid more stable, and the abrasive particles on its surface can generate greater pressure and shear force on the surface of the object being polished, thereby improving polishing efficiency and polishing capability.

[0006] However, the square magnets used in the above design make it difficult to process the magnet array. The magnetic induction intensity on the magnet surface is only less than 400mT at a distance of 2mm from the magnet surface, and the polishing distance is very limited. Summary of the Invention

[0007] The purpose of this invention is to provide a magnetic field array polishing device. This magnetic field array polishing device is simple to process, and the magnetic induction intensity at a distance of 6mm from the surface of the N pole of the magnet reaches 610mT. Its magnetic properties are much stronger than those of the prior art, and the polishing distance is also 3 times that of the prior art.

[0008] To achieve the above objectives, the present invention provides a magnetic field array polishing apparatus, comprising:

[0009] An array carrier has two rows of edge magnet groups and one row of middle magnet groups on its side. The two rows of edge magnet groups are respectively located at both ends of the side of the array carrier, and the middle magnet group is located in the middle of the side of the array carrier. The first magnets on the two rows of edge magnet groups and the second magnets on the row of middle magnet groups are all cylindrical magnets of the same size. The outward magnetic poles of adjacent first magnets in the same row are opposite, and the outward magnetic poles of two first magnets in the same axial direction are opposite. The outward magnetic poles of the second magnets are both N poles. The second magnets on the middle magnet group and the first magnets on the edge magnet groups are arranged alternately.

[0010] A rotating shaft, one end of which is inserted into the bottom of the array carrier, and the other end of which extends out of the array carrier, is connected to an external output source to drive the array carrier to rotate;

[0011] An outer cover, which is fitted over the outside of the array carrier.

[0012] Preferably, the side of the array carrier is provided with mounting holes corresponding to the first magnet and the second magnet.

[0013] Preferably, the included angle between adjacent first magnets and adjacent second magnets is 60°, and the included angle between the first magnet and adjacent second magnets is 30°.

[0014] Preferably, the distance from the center of the first magnet to the nearest end of the array carrier is greater than the radius of the first magnet.

[0015] Preferably, the radius of the first magnet is 4 mm, and the distance from the center of the first magnet to the nearest end of the array carrier is 5.5 mm.

[0016] Preferably, the array carrier is an aluminum alloy cylinder with a diameter of 30 mm and a height of 30 mm.

[0017] Preferably, the rotating shaft is fixed inside the array carrier by a pin.

[0018] Preferably, the side of the array carrier is provided with two first through holes and one second through hole, the axes of the first through hole and the second through hole are perpendicular to each other, the rotating shaft is provided with insertion holes corresponding to the first through hole and the second through hole, and the rotating shaft is fixed to the array carrier by three pins passing through the corresponding first through hole and second through hole.

[0019] Preferably, the centers of the two first perforations are collinear with the center lines of the two rows of edge magnet groups.

[0020] Preferably, the second perforation is located at the center of the side of the array carrier, and its center is collinear with the center line of the intermediate magnet group.

[0021] The beneficial effects of this invention are as follows: It makes full use of the excellent magnetic properties of neodymium iron boron, so that the effective polishing distance of the magnetic field array reaches 6mm, and the magnetic induction intensity at this point is above 0.61T, which is much higher than the magnetic induction intensity of the magnetic field generated by the Heilbeck array. Moreover, the magnetic field with each N pole facing outward has a distinct brush shape. The brush-shaped magnetic fields of multiple N poles are distributed in a continuous "S" shape when viewed from the side of the array carrier. When the array rotates one revolution, the number of times and the intensity of the magnets scratching any 30mm long line segment outside the carrier parallel to the axis of the array carrier are consistent, making the magnetorheological polishing more uniform and thorough, and improving the efficiency and capability of magnetorheological polishing.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 The changes of abrasive grains and iron powder particles under the presence and absence of a magnetic field and external shear strain are shown.

[0025] Figure 2 A schematic diagram of a prior art polishing array is shown;

[0026] Figure 3 A schematic diagram of a magnetic field array polishing device according to an embodiment of the present invention is shown;

[0027] Figure 4 A schematic diagram of an array carrier structure according to an embodiment of the present invention is shown;

[0028] Figure 5 A schematic diagram of a magnetic field array polishing device according to an embodiment of the present invention is shown (excluding the outer casing);

[0029] Figure 6 A schematic diagram of a rotating shaft structure according to an embodiment of the present invention is shown;

[0030] Figure 7 A simulation result of the magnetic field of an embodiment of the present invention is shown. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0032] Please refer to Figures 2-7 This embodiment discloses a magnetic field array polishing device, including an array carrier 1, a rotating shaft 2, and an outer sleeve 3. The array carrier 1 has two rows of edge magnet groups 11 and one row of middle magnet groups 12 arranged on its side. The two rows of edge magnet groups 11 are respectively located at both ends of the side of the array carrier 1, and the middle magnet groups 12 are located in the middle of the side of the array carrier 1. The first magnets 111 on the two rows of edge magnet groups 11 and the second magnets 121 on the row of middle magnet groups 12 are all cylindrical magnets of the same size. The outward magnetic poles of adjacent first magnets 111 in the same row are opposite, and the outward magnetic poles of two first magnets 111 in the same axial direction are opposite. The outward magnetic poles of the second magnets 121 are both N poles. The second magnets 121 on the middle magnet group 12 and the first magnets 111 on the edge magnet groups 11 are arranged alternately. One end of the rotating shaft 2 is inserted into the bottom of the array carrier 1, and the other end extends out of the array carrier 1. The rotating shaft 2 is connected to an external output source to drive the array carrier 1 to rotate. The outer sleeve 3 is fitted over the outside of the array carrier 1. The side of the array carrier 1 is provided with mounting holes 101 corresponding to the first magnet 111 and the second magnet 121.

[0033] In this embodiment, the array carrier 1 is a 6061 aluminum alloy cylinder with a diameter of 30 mm and a height of 30 mm. The first magnet 111 and the second magnet 121 are both N52 permanent magnets with a diameter of 8 mm and a thickness of 5 mm. The rotating shaft 2 is a 304 stainless steel cylindrical rotating shaft with a diameter of 7 mm and a thickness of 90 mm. The outer sleeve 3 is a uniform copper sleeve with an inner diameter of 30 mm, an outer diameter of 34 mm, and a height of 30 mm.

[0034] The magnets in the prior art are cuboids, which requires the magnetic field carrier to be processed with square holes and chamfers at the corners of the holes, making the processing very troublesome. In contrast, this embodiment only requires drilling round holes and through holes at the corresponding positions, making the processing simpler and the production efficiency higher.

[0035] Please refer to Figures 2-5 In the actual processing, a CNC machine tool is used to drill holes in the array carrier 1 blank to create mounting holes 101. The rows are arranged from top to bottom as the first row, second row, and third row. The first row corresponds to the first end of the array carrier 1, and the third row corresponds to the second end of the array carrier 1. The first and third rows correspond to the two rows of edge magnet groups 11, and the second row corresponds to the middle magnet group 12. Each row has six mounting holes 101, with a 60° interval between adjacent mounting holes 101. The diameter of the drilled holes is 8mm, and the depth is 5mm. The mounting holes 101 in the first row are numbered 11, 12, 13, 14, 15, and 16; the mounting holes 101 in the second row are numbered 21, 22, 23, 24, 25, and 26; and the mounting holes 101 in the third row are numbered 31, 32, 33, 34, 35, and 36. The mounting holes 101 in the first and third rows correspond one-to-one. The angle between the second row of mounting holes 101 and the adjacent third row of mounting holes 101 is 30°, that is, the angle between hole 11 and hole 21 is 30°. The distance from the first row of mounting holes 101 to the first end of the array carrier 1 is the same as the distance from the third row of mounting holes 101 to the second end of the array carrier 1, both being 5.5mm. The distance from the second row of mounting holes 101 to both ends of the array carrier 1 is the same, both being 15mm. After the mounting holes 101 are drilled, the first magnet 111 and the second magnet 121 are inserted into the corresponding mounting holes 101.

[0036] Specifically, the included angle between adjacent first magnets 111 and adjacent second magnets 121 is 60°, the included angle between first magnet 111 and adjacent second magnet 121 is 30°, the distance from the center of the first magnet 111 to the nearest end of the array carrier 1 is greater than the radius of the first magnet 111, and the distance from the center of the first magnet 111 to the nearest end of the array carrier 1 is 5.5mm.

[0037] In this embodiment, the outward-facing magnetic poles of holes 11-16 are N, S, N, S, N, S, respectively; the outward-facing magnetic poles of holes 31-36 are S, N, S, N, S, N, respectively; and the outward-facing magnetic poles of holes 21-26 are all N. This results in a distinct brush-like magnetic field for each N-pole, expanding the polishing range. The multiple brush-like magnetic fields of the N poles, viewed from the side of the array carrier, form a continuous, S-shaped distribution. When the array rotates one revolution, the number of times and intensity of magnetic strokes along any 30mm segment outside the carrier parallel to the axial direction of array carrier 1 are consistent, making magnetorheological polishing more uniform and thorough, thus improving the efficiency and capability of magnetorheological polishing.

[0038] like Figure 7 As shown, this embodiment makes full use of the excellent magnetic properties of neodymium iron boron, so that the effective polishing distance of the magnetic field array reaches 6mm, and the magnetic induction intensity at this point is above 0.61T, which is much higher than the magnetic induction intensity of the magnetic field generated by the Heilbeck array.

[0039] To ensure that the array carrier 1 can be driven by the rotating shaft 2, the rotating shaft 2 is fixed inside the array carrier 1 by pins 21. Specifically, the side of the array carrier 1 is provided with two first through holes 102 and one second through hole 103. The axes of the first through holes 102 and the second through holes 103 are perpendicular to each other. The rotating shaft 2 is provided with insertion holes 201 corresponding to the first through holes 102 and the second through holes 103. The rotating shaft 2 is fixed to the array carrier 1 by three pins 21 passing through the corresponding first through holes 102 and the second through holes 103. The centers of the two first through holes 102 are collinear with the center lines of the two rows of edge magnet groups 11. The second through hole 103 is located at the center of the side of the array carrier 1, and its center is collinear with the center line of the middle magnet group 12.

[0040] Specifically, during drilling, a first through hole 102 and a second through hole 103 are drilled on the side of the array carrier 1. In this embodiment, the two first through holes 102 are located on both sides of hole 21, and the centers of the three holes are on the same vertical line. One end of one first through hole 102 is located between holes 11 and 12, and the other end is located between holes 14 and 15; the other first through hole 102 is located between holes 31 and 32, and the other end is located between holes 34 and 35; one end of the second through hole 103 is located between holes 13 and 33, and the other end is located between holes 16 and 36. The diameter of the first through hole 102 and the second through hole 103 is 2 mm, and the depth is 30 mm.

[0041] To install the rotating shaft 2, a hole with a diameter of 7 mm and a depth of 30 mm is drilled in the center of the array carrier 1. Insertion holes 201 corresponding to the two first through holes 102 are drilled on the side of the rotating shaft 2. The distances of the two insertion holes 201 from the ends of the rotating shaft 2 are 5.5 mm and 24.5 mm, respectively. Then, the rotating shaft 2 is rotated 90°, and insertion holes 201 corresponding to the second through hole 103 are drilled. The distance of this insertion hole 201 from the same end is 15 mm. All three insertion holes 201 have a diameter of 2 mm and a depth of 7 mm. During installation, the end of the rotating shaft 2 with the insertion holes 201 is inserted into the center hole of the array carrier 1, so that the corresponding through holes correspond to the corresponding insertion holes. Then, the pin 21 is inserted to connect the array carrier 1 and the rotating shaft 2.

[0042] After sequentially installing the magnet, rotating shaft 2, and pin 21 into the array carrier 1, the outer jacket 3, heated in a water bath, is then rotated and fitted onto the entire array carrier 1. Assembly is complete once the magnetic field array has completely cooled. The Curie temperature (magnetic field failure temperature) of neodymium iron boron is as high as 300°C, while the water bath heating temperature is only below 100°C. Therefore, the above operation will not cause demagnetization of neodymium iron boron.

[0043] In summary, this embodiment fully utilizes the excellent magnetic properties of neodymium iron boron, enabling the effective polishing distance of the magnetic field array to reach 6mm, with a magnetic induction intensity of over 0.61T at this point, far exceeding the magnetic induction intensity of the magnetic field generated by the Heilbeck array. Moreover, the magnetic field with each N pole facing outward exhibits a distinct brush-like shape, and the multiple brush-like magnetic fields of the N poles are distributed in a continuous "S"-shaped pattern when viewed from the side of the array carrier 1. When the array rotates one revolution, the number of times and intensity of the magnets grazing any 30mm long line segment outside the carrier parallel to the axis of the array carrier 1 are consistent, making the magnetorheological polishing more uniform and thorough, and improving the efficiency and capability of magnetorheological polishing.

[0044] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0045] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A magnetic field array polishing device, characterized in that, include: An array carrier has two rows of edge magnet groups and one row of middle magnet groups on its side. The two rows of edge magnet groups are respectively located at both ends of the side of the array carrier, and the middle magnet group is located in the middle of the side of the array carrier. The first magnets on the two rows of edge magnet groups and the second magnets on the row of middle magnet groups are all cylindrical magnets of the same size. The outward magnetic poles of adjacent first magnets in the same row are opposite, and the outward magnetic poles of two first magnets in the same axial direction are opposite. The outward magnetic poles of the second magnets are both N poles. The second magnets on the middle magnet group and the first magnets on the edge magnet groups are arranged alternately. A rotating shaft, one end of which is inserted into the bottom of the array carrier, and the other end of which extends out of the array carrier, is connected to an external output source to drive the array carrier to rotate; An outer cover, which is fitted over the outside of the array carrier.

2. The magnetic field array polishing device according to claim 1, characterized in that, The array carrier has mounting holes on its side corresponding to the first magnet and the second magnet.

3. The magnetic field array polishing device according to claim 1, characterized in that, The included angle between adjacent first magnets and adjacent second magnets is 60°, and the included angle between the first magnet and adjacent second magnets is 30°.

4. The magnetic field array polishing device according to claim 1, characterized in that, The distance from the center of the first magnet to the nearest end of the array carrier is greater than the radius of the first magnet.

5. The magnetic field array polishing device according to claim 4, characterized in that, The radius of the first magnet is 4 mm, and the distance from the center of the first magnet to the nearest end of the array carrier is 5.5 mm.

6. The magnetic field array polishing device according to claim 5, characterized in that, The array carrier is an aluminum alloy cylinder with a diameter of 30 mm and a height of 30 mm.

7. The magnetic field array polishing apparatus according to any one of claims 1-6, characterized in that, The rotating shaft is fixed inside the array carrier by a pin.

8. The magnetic field array polishing apparatus according to claim 7, characterized in that, The array carrier has two first through holes and one second through hole on its side. The axes of the first through hole and the second through hole are perpendicular to each other. The rotating shaft has insertion holes corresponding to the first through hole and the second through hole. The rotating shaft is fixed to the array carrier by passing through the corresponding first through hole and second through hole via three pins.

9. The magnetic field array polishing apparatus according to claim 8, characterized in that, The centers of the two first perforations are collinear with the center lines of the two rows of edge magnets, respectively.

10. The magnetic field array polishing apparatus according to claim 9, characterized in that, The second perforation is located at the center of the side of the array carrier, and its center is collinear with the center line of the middle magnet group.

Images