Grinding device for polishing gyromagnetic ferrite single crystal pellets

Abstract

The invention discloses a grinding device for polishing gyromagnetic ferrite single crystal pellets, and belongs to the field of post-processing equipment of brittle and hard spherical materials, the grinding device comprises a grinding cavity (3) and a polishing shaft (1), the inner wall of the grinding cavity (3) is a curved surface, a grinding cover (2) with a through hole in the center is arranged at the upper end of the grinding cavity (3), and the polishing shaft (1) extends into the inner bottom of the grinding cavity (3). Polishing slurry (4) is arranged on the side face of the polishing shaft (1), and an axial V-shaped groove (7) is formed in the polishing slurry (4). The ball in the polishing shaft is in point and curved surface contact with the inner wall of the grinding cavity, so that the ball is more easily driven to do phase-changing orientation grinding motion, the grinding track on the surface of the ball is uniformly distributed, the diameter of a small ball is more uniform, the roundness is smaller, the smoothness is better, and the grinding quality of the small ball is improved; meanwhile, the polishing device is simple in structure, small in size, convenient to use and capable of being used for polishing the single crystal balls in batches.

Description

Technical Field

[0001] The invention relates to the field of post-processing equipment for brittle and hard spherical materials, and in particular to a grinding device for polishing a gyromagnetic ferrite single crystal ball. Background Art

[0002] Gyromagnetic ferrite is a ferrimagnetic material. When it is used in gyromagnetic single crystal magnetic tuning devices, it is often processed into spherical components with high surface finish. As the core component of magnetic tuning microwave devices, the diameter of the single crystal sphere is crucial to the regulation of the device coupling loop parameters. Over-coupling or weak coupling can cause problems such as bandwidth, ripple, and false response during device debugging. At the same time, the roundness difference of the gyromagnetic ferrite single crystal sphere can easily excite the static magnetomode, causing the resonance frequency to shift, thus leading to problems such as narrow generation width of microwave devices, poor sideband steepness, poor intra-band flatness, and poor phase noise. The surface finish of the gyromagnetic ferrite single crystal sphere can directly affect the resonant linewidth of the single crystal sphere. Problems such as surface pits, defects, and cracks can cause the linewidth of the single crystal sphere to increase significantly.

[0003] Therefore, in order to reduce the impact of post-processing on the performance of ferrite single crystal balls, meet the application of single crystal balls in microwave devices, and improve the performance of microwave devices, it is urgent to find an efficient and simple grinding and polishing method. China Patent Publication No. CN109719603A discloses a YIG ball polishing device, which pressurizes and fixes the ball on the lower grinding disc by the upper grinding disc, and drives the ball to rotate by the rotation of the lower grinding disc to achieve ball polishing. The ball and the upper grinding disc are point-to-plane contact, which is prone to reduce the roundness of the ball and surface damage, resulting in a low product yield, and the processing device is large in size and complex in structure, which is not conducive to mass production. China Patent Publication No. CN 111872750 A discloses a polishing device that uses an asymmetric groove for grinding and polishing. Although it has a simple structure and stable processing, the main part is made of pure copper. Since the device is still point-to-plane contact when polishing, the contact part of the upper grinding disc will be polished for a long time and the corresponding dents will be engraved on the upper plane, thereby affecting the processing efficiency and increasing the difficulty of processing.

[0004] Therefore, there is an urgent need in the art for a polishing and grinding device that can achieve more effective processing efficiency, reduce processing difficulty, improve polishing effect, and has a simple structure. Summary of the invention

[0005] The purpose of the present invention is to provide a grinding device for polishing a small gyromagnetic ferrite single crystal ball to solve the above problems.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a grinding device for polishing a small single crystal ball of rotating magnetic ferrite, comprising a grinding chamber and a polishing shaft, the inner wall of the grinding chamber is a curved surface, a grinding cover with a through hole in the center is arranged at the upper end of the grinding chamber, the polishing shaft extends from the grinding cover through the through hole into the bottom of the grinding chamber, a polishing slurry is arranged on the side of the polishing shaft, an axial V-groove is arranged on the polishing slurry at a position adjacent to the inner wall of the grinding chamber; a polishing shaft for driving the polishing slurry to rotate is arranged at the upper end of the grinding chamber, and the polishing shaft is connected to the polishing slurry.

[0007] As a preferred technical solution, a positioning groove is provided on the upper part of the polishing shaft, and the precision-machined polishing shaft is fixed on the polishing slurry by screws, so that the small balls in the V-groove of the polishing slurry maintain multi-point contact with the inner wall of the grinding chamber.

[0008] As a preferred technical solution, the polishing shaft is flush with the bottom of the polishing slurry to prevent the balls from falling from the bottom during the polishing process.

[0009] As a preferred technical solution, the grinding cover is fixed to the grinding chamber via a threaded connection to prevent the grinding liquid from spilling out during the polishing process.

[0010] As a preferred technical solution, the rotating unit is controlled by the grinding slurry outside the grinding chamber, and the speed and rotation direction can be manually controlled. The grinding slurry in the grinding chamber rotates by rotating the rotating unit, driving the balls to rotate and revolve, thereby achieving a ball polishing effect.

[0011] As a preferred technical solution, the grinding cover and the grinding chamber are made of brass, the polishing slurry is made of one of polyurethane, polytetrafluoroethylene, polysulfone, and brass, and the polishing shaft is made of brass or stainless steel.

[0012] Compared with the prior art, the advantages of the present invention are: the sphere in the polishing shaft of the grinding device of the present invention and the inner wall of the grinding chamber are point-to-surface contact. Compared with the fixed three-point contact between a point and a plane, the contact points of the present invention are greater than or equal to 3. For single crystal small balls with poor roundness, the contact points are more, such as Figure 1 As shown, it is easier to drive the ball to perform variable relative azimuth grinding motion, so that the grinding track on the surface of the ball is evenly distributed, so that the diameter of the ball is more uniform, the roundness is smaller, the smoothness is better, and the grinding quality of the ball is improved; at the same time, the structure of the present invention is simple, the volume is small, and it is easy to use, and it can be used for batch single crystal ball polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of contact points of three-point contact (a) of plane grinding and polishing in the prior art and four-point contact (b) of curved surface grinding and polishing of the present invention; Figure 2is a front cross-sectional view of the grinding device of the present invention; Figure 3 A top view of the polishing slurry inside the grinding chamber of the grinding device of the present invention; Figure 4 This is a comparison diagram of the spinning ferrite single crystal ball before and after polishing of Sample 1 in the embodiment.

[0014] In the figure: 1. polishing shaft; 2. grinding cover; 3. grinding chamber; 4. polishing slurry; 5. screw; 6. small ball; 7. V-groove. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings.

[0016] It should be noted that the "roundness" mentioned in this application refers to geometric roundness, that is, the maximum deviation of the distance from each point on the surface of a sphere to the center of the sphere. For an ideal sphere, the roundness is zero.

[0017] Example:

[0018] See also Figure 2 A grinding device for polishing a single crystal ball of a rotating magnetic ferrite comprises a grinding chamber 3 and a polishing shaft 1. The inner wall of the grinding chamber 3 is a curved surface. In this embodiment, the cross section of the inner wall of the grinding chamber 3 is a circle. Figure 3 As shown, a grinding cover 2 with a through hole in the center is provided at the upper end of the grinding chamber 3, and the polishing shaft 1 extends from the grinding cover 2 through the through hole into the bottom of the grinding chamber 3. A polishing slurry 4 is provided on the side of the polishing shaft 1, and an axial V-shaped groove 7 is provided on the polishing slurry 4 at a position adjacent to the inner wall of the grinding chamber 3; The polishing shaft 1 is fixedly connected to the polishing slurry 4 by screws 5, and it is ensured that the polishing shaft 1 is flush with the bottom of the polishing slurry 4; the grinding cover 2 is fixed to the grinding chamber 3 by threaded connection; The polishing requirements of single crystal balls 6 of different sizes can be achieved by replacing the polishing slurry of V-grooves 7 of different depths, wherein the relationship between the depth d of the V-groove 7 and the radius r of the ball 6 satisfies d=2r-0.15 (mm); Table 1 lists the changes in diameter and roundness of two different sizes of single crystal ball samples before and after polishing using the device of this embodiment. The "roundness" mentioned in this application refers to geometric roundness, that is, the maximum deviation of the distance from each point on the surface of the sphere to the center of the sphere. An ideal sphere has a roundness of zero, which can be tested by a profilometer. From the test results, the roundness of the polished single crystal ball is optimized from 1.5μm to 0.9μm, and the size uniformity is also improved, indicating that this device can effectively improve the size uniformity and roundness of the ball after processing. Figure 4 As shown, after being polished by the device, the surface smoothness of the ferrite single crystal ball is significantly improved through microscopic observation, achieving a polishing effect.

[0019] Table 1 Changes in diameter and roundness of ball samples of different sizes before and after polishing

[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A grinding device for polishing a single crystal ball of a spinning ferrite, characterized in that: The invention comprises a grinding chamber (3) and a polishing shaft (1), wherein the inner wall of the grinding chamber (3) is a curved surface, a grinding cover (2) with a through hole in the center is arranged at the upper end of the grinding chamber (3), the polishing shaft (1) extends from the grinding cover (2) through the through hole into the bottom of the grinding chamber (3), a polishing slurry (4) is arranged on the side of the polishing shaft (1), and an axial V-shaped groove (7) is arranged on the polishing slurry (4) at a position adjacent to the inner wall of the grinding chamber (3); and a polishing shaft for driving the polishing slurry (4) to rotate is arranged at the upper end of the grinding chamber (3).

2. The grinding device for polishing a gyromagnetic ferrite single crystal ball according to claim 1, characterized in that: The polishing shaft (1) is fixedly connected to the polishing slurry (4) via screws (5).

3. The grinding device for polishing a gyromagnetic ferrite single crystal ball according to claim 1, characterized in that: The polishing shaft (1) is flush with the bottom of the polishing slurry (4).

4. The grinding device for polishing a gyromagnetic ferrite single crystal ball according to claim 1, characterized in that: The grinding cover (2) and the grinding chamber (3) are fixed via threaded connection.

5. The grinding device for polishing a gyromagnetic ferrite single crystal ball according to claim 1, characterized in that: The grinding cover (2) and the grinding chamber (3) are made of brass, the polishing slurry (4) is made of one of polyurethane, polytetrafluoroethylene, polysulfone and brass, and the polishing shaft (1) is made of brass or stainless steel.

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