Method for adjusting magnetic field intensity uniformity of magnetic pole of radiation orientation magnetic ring

Abstract

The invention relates to a method for adjusting the magnetic field intensity uniformity of magnetic poles of a radiation orientation magnetic ring, belongs to the technical field of magnetic field uniformity control, and solves the problems in the prior art that the difference value of nonuniformity between the magnetic poles of a magnetic ring is large; the magnetic field intensity uniformity of the magnetic poles of the magnetic rings is not high; and the distribution consistency of the magnetic field intensity of the magnetic poles of the magnetic rings is difficult to accurately control and adjust. A radiation orientation magnetic ring magnetic pole magnetic field intensity uniformity adjusting method sequentially carries out magnetic field intensity local adjustment on magnetic ring magnetic poles in sequence in an open circuit environment, and the adjusting method comprises the steps that an adjusting magnetic field is applied to each magnetic pole at the local position of a single magnetic pole, and meanwhile the surface area of each magnetic pole is heated to a certain temperature. And the regulation and control preparation of the high-uniformity radiation orientation magnetic ring is realized.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic field uniformity control, and in particular to a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring. Background Art

[0002] As an important type of functional material, magnetic materials have been widely used in advanced manufacturing fields such as precision machine tools, aerospace equipment, industrial robots and power equipment. Radiation-oriented magnetic rings are a type of magnetic material with a special orientation structure. The easy magnetization direction of its grains is radially arranged. The overall structure is compact, the assembly is tight, the stray magnetic field is small, and the output magnetic field is highly stable. It is particularly suitable for high-end permanent magnet motors and high-precision magnetic sensors.

[0003] Traditional methods for making radiation-oriented magnetic rings include splicing, sintering, bonding and hot pressing / hot deformation integral magnetic rings. Magnetic rings prepared by different methods have different performances. According to the requirements of the service environment, magnetic rings with corresponding magnetic field distribution and strength such as internal and external monopole radiation magnetization and multipole radiation magnetization can be achieved.

[0004] In order to ensure the stable and reliable operation of magnetic equipment, the magnetic field intensity distribution of the magnetic ring poles usually needs to be highly consistent. Due to limitations in manufacturing processes and other aspects, it is difficult to achieve complete consistency in the organizational structure and magnetization state of the magnetic ring, resulting in differences in the magnetic field intensity distribution of the magnetic ring poles. The difference in uniformity between the poles of existing magnetic rings generally exceeds 4%, and it is very difficult to further improve the consistency of the magnetic field intensity distribution by improving the uniformity of the magnetic ring itself.

[0005] In response to the application requirements of higher uniformity magnetic rings, optimization can be achieved by adding shim plates, or partially demagnetizing the magnetized area of ​​the magnetic ring through an external magnetic field. These processing methods require complex designs and limited operating space. It is difficult to achieve more accurate adjustment of the magnetic field change and is not suitable for small-sized multi-pole magnetic rings with many poles. Summary of the invention

[0006] In view of the above analysis, an embodiment of the present invention aims to provide a method for adjusting the uniformity of the magnetic field strength of the magnetic poles of a radiation-oriented magnetic ring, so as to solve at least one of the problems that the difference in unevenness between the magnetic poles of the existing magnetic ring is large, the uniformity of the magnetic field strength of the magnetic poles of the magnetic ring is not high, and the consistency of the magnetic field strength distribution of the magnetic poles of the magnetic ring is difficult to accurately control and adjust.

[0007] A method for adjusting the uniformity of the magnetic field strength of a radiation-oriented magnetic ring pole is disclosed. The magnetic field strength of the magnetic ring pole is locally adjusted in sequence under an open circuit environment. The adjustment method is to apply a regulating magnetic field to the pole at a local position of a single pole and heat the surface area of ​​the pole to a certain temperature.

[0008] Furthermore, the order of adjustment is to adjust the magnetic field strength of each magnetic pole in order from large to small according to the difference between the magnetic field strength of the magnetic pole and the target value.

[0009] Preferably, the local position of the single magnetic pole is a peak region of each magnetic pole, and the included polar angle width is no greater than 20°.

[0010] It should be noted that the magnitude of the regulating magnetic field applied during the adjustment process is no greater than 5000 Gs, and the distance from the surface of the magnetic ring is no greater than 0.5 mm.

[0011] Furthermore, the adjustment temperature range applied during the adjustment process is 150-400°C, and the temperature action area is no larger than 1mm 2 , single time is no more than 3s.

[0012] It is worth noting that the number of local adjustments of the magnetic field strength at each magnetic pole is greater than 1, and the range of the single adjustment magnetic pole difference is 1 to 70 Gs.

[0013] Specifically, before the uniformity adjustment of the magnetic field strength of the magnetic ring poles is performed, the magnetic ring is subjected to unipolar radiation orientation magnetization or multipolar radiation orientation magnetization, and the magnetic ring is placed in a corresponding orientation magnetic field for saturation magnetization. After magnetization, the magnetic field strength of the magnetic ring poles is 1000 to 5000 Gs, and the deviation range of each magnetic pole strength is 2 to 15%.

[0014] Preferably, the method for locally adjusting the magnetic field strength of the magnetic ring poles is applicable to magnetic ring size characteristics including: the axial height of the magnetic ring is not less than 1 mm, the radius of the magnetic ring is in the range of 5 to 30 mm, and the ratio of the inner and outer diameters is 0.55 to 0.95.

[0015] Exemplarily, the method for locally adjusting the magnetic field strength of a magnetic ring pole is applicable to a magnetic ring made of a permanent magnetic material, with a coercive force of not less than 10 kOe and a magnetic energy product of not less than 10 MGOe.

[0016] Specifically, the uniformity of the magnetic field intensity distribution of the magnetic ring magnetic poles is less than 2% after adjustment.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0018] 1. In order to solve the problem that the magnetic field adjustment position of the magnetic poles of a multi-polar magnetic ring needs to be consistent with that during orientation preparation, the present invention adopts a method of adjusting the local magnetization characteristics, processes the magnetic poles of the radiation-oriented magnetic ring in sequence according to the magnitude of the magnetic pole strength deviation, and strictly controls the polar angle width of the adjustment position, thereby reducing the impact on adjacent magnetic poles and improving the adjustment accuracy.

[0019] 2. In order to solve the problem that the magnetization state of small-sized magnetic rings is easily affected by external magnetic fields and has significant hysteresis phenomenon, the present invention adopts magnetic field and temperature field to perform composite adjustment on the local magnetization state of the magnetic pole, and accurately controls the application area of ​​the magnetic field and temperature field, as well as the time and number of adjustments for a single adjustment. By focusing the processing of a small area in a short time, the adjustment stability and accuracy are significantly improved, the adjustment deviation is effectively reduced, and the loss of magnetic properties outside the processing area is reduced.

[0020] 3. The present invention adopts a method of adjusting the local magnetization characteristics, processes the radiation-oriented magnetic ring poles in sequence according to the magnitude of the magnetic pole strength deviation, strictly controls the polar angle width of the adjustment position, and uses the magnetic field and temperature field to perform a composite adjustment on the local magnetization state of the magnetic pole, thereby achieving a significant improvement in the adjustment stability and accuracy, effectively reducing the adjustment deviation, and reducing the magnetic property loss outside the processing area, thereby obtaining a magnetic field intensity distribution with high uniformity and consistency of the magnetic poles, and the magnetic field strength deviation of the magnetic ring poles is within 2%, meeting the application requirements of high-uniformity magnetic rings.

[0021] 4. The present invention utilizes a method of compositely processing the magnetic field and temperature field of the local magnetization characteristics of the magnetic pole of the magnetic ring to achieve the accuracy and stability of the magnetic pole magnetic field strength difference adjustment control, and can obtain a radiation-oriented magnetic ring with excellent uniformity of the magnetic pole magnetic field strength. At the same time, it significantly improves the axial consistency of the magnetic ring, and has basically no effect on the magnetic properties of the adjacent areas of the local adjustment of the magnetic ring.

[0022] 5. The present invention accurately controls the application area of ​​the magnetic field and temperature field, as well as the time and number of adjustments for a single adjustment. By focusing on a small area in a short time, the impact on adjacent areas is effectively reduced, thereby achieving higher stability and control accuracy.

[0023] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0025] Figure 1 Magnetic field intensity distribution curve after the magnetic poles of the magnetic ring are adjusted in Example 2 of the present invention;

[0026] Figure 2 Magnetic field intensity distribution curve of the axial magnetic pole of the magnetic ring in Example 3 of the present invention. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0028] For large magnets, the uniformity of the magnetic field can be adjusted by adding shims. Shims are generally metal sheets used to adjust the uniformity of the magnetic field. When adjusting the magnetic field, these shims are placed inside or outside the magnet. By changing their position or number, the uniformity of the magnetic field is optimized, which requires a larger placement space.

[0029] During the preparation process of existing small-sized multi-polar magnetic rings, the deviation of the magnetic field strength of the magnetic poles of the magnetic rings is usually controlled as much as possible within a relatively low range (generally above 4%). However, as the requirements for the use of small-sized multi-polar magnetic rings in high-precision fields such as motors become increasingly higher, the deviation of the magnetic field strength of the magnetic poles above 4% can no longer meet the application requirements of high-precision fields, and the deviation of the magnetic field strength of the magnetic poles needs to be further reduced.

[0030] Small-sized magnetic rings are limited by size, and multi-pole magnetic rings are limited by geometric shape. The operating space is limited, making it difficult to place shims. It is difficult to determine the appropriate magnetic field strength and accurately control the adjustment amount by only partially demagnetizing the magnetized area of ​​the magnetic ring through an external magnetic field.

[0031] The magnetic field adjustment position of the magnetic poles of a multi-pole magnetic ring needs to be consistent with that during the orientation preparation. Any misalignment may affect the magnetic field distribution and performance of the final product, which places higher requirements on the precise control of the adjustment process. The magnetization state of a small-sized magnetic ring interacts more significantly with the external magnetic field, and its magnetic field strength is more susceptible to fluctuations due to the external magnetic field. Due to its size limitation, the hysteresis phenomenon is more significant, and the magnetic field stability is poor, requiring more precise control to adjust its magnetic field strength. In summary, small-sized and multi-pole magnetic rings have higher requirements for the uniformity adjustment of magnetic field strength due to their size limitations, design complexity, and precision requirements for magnetic field adjustment.

[0032] A specific embodiment of the present invention discloses a method for adjusting the uniformity of the magnetic field strength of a radiation-oriented magnetic ring pole, in which the magnetic field strength of the magnetic ring pole is locally adjusted in sequence under an open circuit environment. The adjustment method is to apply a regulating magnetic field to the pole at a local position of a single pole, and at the same time heat the surface area of ​​the pole to a certain temperature.

[0033] Specifically, the adjustment sequence is to adjust the magnetic field strength of each magnetic pole in order from large to small according to the difference between the magnetic field strength of the magnetic pole and the target value, which can gradually reduce the fluctuation of the magnetic field, thereby improving the stability of the magnetic field.

[0034] Preferably, the local position of the single magnetic pole is the peak area of ​​each magnetic pole, and the polar angle width included is no more than 20°. Too large a polar angle width will affect the magnetic properties of adjacent areas.

[0035] Furthermore, the magnitude of the regulating magnetic field applied during the adjustment process is no greater than 5000Gs, and the distance from the surface of the magnetic ring is no greater than 0.5mm. Preferably, the regulating magnetic field is 2000Gs, 2500Gs, 3000Gs, 3500Gs, 4000Gs, 4500Gs, or 5000Gs.

[0036] If the applied magnetic field strength is too large, it will cause a significant change in the magnetization state of the magnetic ring, or cause a large loss in magnetic field strength, causing the magnetic ring to fail to meet the magnetic performance requirements.

[0037] It should be noted that the adjustment magnetic field is applied through a demagnetization coil.

[0038] Furthermore, the magnetic characteristics of the local position of the magnetic ring magnetic pole adjust the surface heating temperature in the range of 150 to 400°C, and the temperature action area is no more than 1mm 2 , and the single time is no more than 3s. Preferably, the heating temperature is 150°C, 200°C, 250°C, 300°C, 350°C, or 400°C.

[0039] The magnetic pole surface area is heated by heat conduction through a heater, and the range of the effective area is controlled by the contact area between the heater and the magnetic pole surface.

[0040] It is worth noting that the number of local adjustments of the magnetic field strength at each magnetic pole is greater than 1, and the range of the single adjustment magnetic pole difference is 1 to 70 Gs.

[0041] During the local adjustment of the magnetic field strength of the magnetic pole of the magnetic ring, under the combined action of the magnetic field of the demagnetization coil and the high temperature of the surface, the magnetization state of the magnetic pole changes, forming a continuous micro-demagnetization area, and effectively controlling the range of the demagnetization area to achieve the control of the magnetic field strength of the magnetic pole and reduce the magnetic pole deviation.

[0042] It should be noted that before the uniformity adjustment of the magnetic field strength of the magnetic ring poles is carried out, the magnetic ring is subjected to unipolar radiation orientation magnetization or multipolar radiation orientation magnetization, and the magnetic ring is placed in the corresponding orientation magnetic field for saturation magnetization. After magnetization, the magnetic field strength of the magnetic ring poles is 1000 to 5000 Gs, and the deviation range of each magnetic pole strength is 2 to 15%.

[0043] After the magnetic ring is magnetized in radiation orientation, the distribution of the magnetic field strength of the magnetic ring poles is obtained in the open circuit state. The target value for uniformity adjustment is selected based on the distribution. The magnetic field strength of the magnetic ring poles is detected after saturation magnetization. According to the magnitude of the magnetic pole strength deviation, the target value for uniformity adjustment of the magnetic ring is determined to meet the uniformity requirements of the magnetic ring.

[0044] It should be noted that the magnetic ring size characteristics applicable to the local adjustment method of the magnetic ring magnetic pole magnetic field strength include: the axial height of the magnetic ring is not less than 1mm, the radius of the magnetic ring is in the range of 5 to 30mm, and the ratio of the inner and outer diameters is 0.55 to 0.95;

[0045] The method for locally adjusting the magnetic field strength of the magnetic ring pole is applicable to a magnetic ring made of permanent magnetic material, with a coercive force of not less than 10 kOe and a magnetic energy product of not less than 10 MGOe.

[0046] Preferably, the uniformity of the magnetic field intensity distribution of the magnetic ring poles is adjusted to be less than 2%.

[0047] In summary, the present invention adopts a method of adjusting the local magnetization characteristics to sequentially process the deviation size of the radiation-oriented magnetic ring pole, and uses different magnetic fields and temperatures to perform composite adjustments on the local magnetization state of the pole according to the control range of the magnetic ring pole position area, thereby achieving significant improvements in adjustment stability and accuracy, effectively reducing adjustment deviations, and reducing magnetic property losses outside the processing area, thereby obtaining a magnetic field intensity distribution with high uniformity and consistency at the pole, and the uniformity of the magnetic field intensity distribution of the magnetic ring pole is within 2%, meeting the application requirements of high-uniformity magnetic rings.

[0048] The method for adjusting the uniformity of the magnetic field intensity of the magnetic poles of a radiation-oriented magnetic ring of the present invention is described below in conjunction with specific embodiments.

[0049] Example 1

[0050] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0051] The processing object is a multi-pole magnetic ring, the magnetic ring dimensions are: magnetic ring radius 16mm, inner and outer diameter ratio 0.78, magnetic ring height 2mm, pole number 4, the magnetic field strength after saturation magnetization of the magnetic ring poles is N pole: 3651Gs, 3884Gs, S pole: 3738Gs, 3977Gs; the magnetic pole strength deviation is 4.3%.

[0052] The specific process is as follows:

[0053] Step 1. Determine the adjustment target value: set the magnetic ring uniformity adjustment target value to 3700Gs;

[0054] Step 2, local adjustment of magnetic pole magnetic field: in an open circuit environment, adjust each magnetic pole in order from large to small according to the difference between the magnetic pole strength and the target value, and adjust in order: N pole 3884Gs, S pole 3977Gs, N pole 3651Gs, S pole 3738Gs area, and adjust the maximum width of the regional polar angle to 10°;

[0055] The magnetic coil is placed directly at the peak area of ​​each magnetic pole, with a distance of 0.5 mm, and a magnetic field of 4500 Gs is applied. At the same time, the surface area of ​​the magnetic ring magnetic pole is heated to 350 ° C and acts on 0.3 mm 2 , single processing time 2s, divided into 5 adjustments, the maximum adjustment difference is 50Gs;

[0056] Under the combined effect of the demagnetization coil magnetic field and the surface temperature, the magnetization state of the area with high magnetization intensity distribution at the magnetic pole changes, forming a continuous micro-demagnetization zone, thereby achieving regulation to reduce the deviation of the magnetic field intensity of the magnetic pole. After adjustment, the magnetic ring naturally returns to the initial temperature and the demagnetization coil is turned off.

[0057] After the test and adjustment, the corresponding magnetic pole sizes are N pole: 3647Gs, 3749Gs, S pole: 3732Gs, 3723Gs. The magnetic pole strength deviation after adjustment is 1.77%, which significantly improves the adjustment control accuracy and obtains excellent uniformity of the magnetic ring pole distribution.

[0058] Example 2

[0059] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0060] The processing object is a sintered radiation-oriented permanent magnet ring. The size of the magnet ring is a radius of 22mm, the ratio of the inner and outer diameters is 0.9, the height of the magnet ring is 12mm, and the magnetic properties of the radiation-oriented magnet ring direct ring-cut samples are a coercive force of 23kOe and a magnetic energy product of 19MGOe. The outer circumference of the magnet ring is the N pole, and the inner side is the S pole. The magnetic field distribution deviation of the N pole on the outer circumference of the magnet ring is adjusted. After saturation magnetization, the distribution of the N pole magnetic field intensity is: the maximum is 2729Gs, the minimum is 2187Gs, and the magnetic pole intensity deviation is 11.03%.

[0061] The specific process is as follows:

[0062] Step 1: Determine the target value for adjustment: the target value for magnetic ring uniformity adjustment is 2200Gs;

[0063] Step 2: Local adjustment of magnetic pole magnetic field: Test the area where the N pole deviates from the target value along the circumference and mark the order in sequence according to the difference. The magnetic adjustment coil is facing the position area where the magnetic pole strength deviates. The corresponding polar angle width of each position area is 15°, the distance is 0.1mm, and the magnetic field is applied at 5000Gs. At the same time, the surface area of ​​the magnetic ring magnetic pole is heated to 400℃, and the application area is 1mm 2 The processing time is 3s, and the adjustment is divided into 15 times. The maximum adjustment difference is 70Gs. The magnetic field intensity of the magnetic pole is reduced along the N-pole axis according to the difference between the magnetic field intensity and 2200Gs. With the continuous increase of the magnetization state change area, the magnetic field intensity distribution of the magnetic ring pole tends to be consistent. After adjustment, the magnetic ring naturally returns to the initial room temperature.

[0064] After the test, the magnetic field intensity distribution of the N pole of the outer circumference of the magnetic ring after adjustment is: the maximum value is 2263Gs, the minimum value is 2176Gs, and the deviation of the circumferential magnetic pole intensity distribution after adjustment is 1.96%, which significantly improves the uniformity of the magnetic field intensity of the magnetic ring magnetic pole. The magnetic field intensity distribution curve after adjustment is as follows Figure 1 shown.

[0065] Example 3

[0066] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0067] The processing object is a multi-pole magnetized radiation-oriented magnetic ring, with a radius of 13.5mm, an inner and outer diameter ratio of 0.59, a height of 10mm, magnetic properties of 15kOe coercive force, and a magnetic energy product of 31MGOe. The magnetic ring is multi-pole oriented magnetized with 10 poles. The magnetic field strength of the axial corresponding magnetic poles at an interval of 2mm is tested in sequence along the axial height direction of the magnetic ring. After multi-pole saturation magnetization of the magnetic ring, the magnetic field strengths of the 5 corresponding S magnetic poles at equal intervals along the axial direction are 2878Gs, 3021Gs, 2804Gs, 2738Gs, and 2763Gs, respectively. The axial magnetic pole strength of the multi-pole magnetic ring is biased by 6.3%.

[0068] The specific process is as follows:

[0069] Step 1: Determine the target value for adjustment: the target value for magnetic ring uniformity adjustment is 2800Gs;

[0070] Step 2, local adjustment of magnetic pole magnetic field: adjust the difference between the magnetic pole strength and the target value in an open circuit environment. The adjustment order is: 3021Gs, 2878Gs, 2738Gs, 2763Gs, 2804Gs area, adjust the maximum width of the regional polar angle to 5°, point the magnetic adjustment coil directly at the peak area of ​​a single magnetic pole position, with a distance of 0.2mm, apply a magnetic field of 2000Gs, and heat the surface area of ​​the magnetic ring magnetic pole to 150℃, acting on 0.6mm 2 , the processing time is 1s, and the magnetic pole strength is adjusted in sequence along the axial direction, divided into 6 adjustments, and the maximum adjustment difference is 25Gs;

[0071] Under the combined effect of the magnetic field and the high temperature of the surface, the magnetization state of the axial magnetic pole position changes, reducing the magnetization intensity of the magnetic pole, and obtaining a magnetic field intensity deviation of the magnetic pole that is reduced according to the design requirements. After adjustment, the magnetic ring naturally returns to its initial temperature.

[0072] After the axial magnetic poles of the magnetic ring are adjusted, the corresponding magnetic pole strengths are: 2811Gs, 2827Gs, 2802Gs, 2729Gs, 2732Gs. After adjustment, the deviation of the axial magnetic pole strength of the multi-pole ring is 1.83%, achieving the adjustment and optimization of the axial magnetic pole uniformity, and obtaining a magnetic ring with high uniformity. The axial magnetic pole magnetic field strength distribution curve is shown in Figure 2As shown (adjusted δ(B T )).

[0073] Comparative Example 1

[0074] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0075] The size and magnetic properties of the magnetic ring are the same as those of Example 1.

[0076] The specific process is basically the same as that of Example 1, except that step 3 is different:

[0077] Step 3: Apply a magnetic field to the entire magnetic ring to adjust it: apply a magnetic field of 5000Gs.

[0078] After the test and adjustment, the magnetic field intensity distribution of the outer circumference of the magnetic ring is: N pole 3649Gs, 3872Gs, S pole: 3735Gs, 3960Gs. The deviation of the circumferential magnetic pole intensity distribution after adjustment is 4.10%.

[0079] Comparative Example 2

[0080] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0081] The size and magnetic properties of the magnetic ring are the same as those of Example 2.

[0082] The specific process is basically the same as that of Example 2, except that step 3 is different:

[0083] Step 3: Place the entire magnetic ring in an oven and heat it to 400°C for 5 seconds. After adjustment, the magnetic ring will naturally return to its initial room temperature.

[0084] After the test and adjustment, the magnetic field intensity distribution of the N-pole on the outer circumference of the magnetic ring is: maximum value 2611Gs, minimum value 2039Gs, and the deviation of the circumferential magnetic pole intensity distribution after adjustment is 12.3%.

[0085] Comparative Example 3

[0086] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0087] The size and magnetic properties of the magnetic ring are the same as those of Example 3.

[0088] The specific process is basically the same as that of Example 2, except that in step 3, the magnetic pole angle control area is larger, 30°.

[0089] After testing the adjusted magnetic ring, the corresponding magnetic pole strengths are: 2835Gs, 2896Gs, 2787Gs, 2709Gs, and 2722Gs. The deviation of the axial magnetic pole strength of the adjusted multi-pole ring is 3.81%.

[0090] Comparative Example 4

[0091] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0092] The size and magnetic properties of the magnetic ring are the same as those of Example 2.

[0093] The specific process is basically the same as that of Example 2, except that in step 3, only one adjustment is performed, and the adjustment time is 1 minute.

[0094] The adjusted magnetic ring was tested and the results showed that the magnetic field strength distribution of the N-pole on the outer circumference of the magnetic ring was as follows: maximum value 2199Gs, minimum value 1531Gs, and the deviation of the adjusted circumferential magnetic pole strength distribution was 17.9%.

[0095] Comparative Example 5

[0096] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0097] The size and magnetic properties of the magnetic ring are the same as those of Example 2.

[0098] The specific process is basically the same as that of Example 2, except that in step 3, the magnetic field is adjusted to be too strong, 6000 Gs.

[0099] The adjusted magnetic ring was tested and the results showed that the magnetic field intensity distribution of the outer circumference of the magnetic ring was as follows: maximum value 2335Gs, minimum value 2156Gs, and the deviation of the circumferential magnetic pole intensity distribution after adjustment was 3.99%.

[0100] Comparative Example 6

[0101] This embodiment provides a method for adjusting the uniformity of magnetic field intensity of magnetic poles of a radiation-oriented magnetic ring.

[0102] The size and magnetic properties of the magnetic ring are the same as those of Example 2.

[0103] The specific process is basically the same as that of Example 2, except that in step 3, the temperature is too high, which is 500°C.

[0104] The adjusted magnetic ring was tested and the results showed that the magnetic field intensity distribution of the outer circumference of the magnetic ring was as follows: maximum value 2327Gs, minimum value 2011Gs, and the deviation of the circumferential magnetic pole intensity distribution after adjustment was 7.28%.

[0105] It can be seen from Examples 1 to 3 that the present invention utilizes a method of compositely processing the local magnetization characteristics of the magnetic poles of the magnetic ring with magnetic field and temperature field to achieve the accuracy and stability of the magnetic pole magnetic field strength difference adjustment control, and can obtain a radiation-oriented magnetic ring with excellent uniformity of magnetic pole magnetic field strength, while significantly improving the axial consistency of the magnetic ring, and the magnetic pole strength deviation meets the requirement of <2%;

[0106] It can be seen from Comparative Example 1 and Example 1 that the magnetic field is applied to the entire magnetic ring to adjust the magnetic field strength. After the adjustment, the distribution deviation of the circumferential magnetic pole strength is still relatively large, at 4.10%;

[0107] It can be seen from Comparative Example 2 and Example 2 that the magnetic ring is heated as a whole and a temperature field is applied to adjust the magnetic field strength. After the adjustment, the distribution deviation of the circumferential magnetic pole strength is higher than that before the adjustment, which is 12.3%;

[0108] It can be seen from Comparative Example 3 and Example 3 that the magnetic pole angle control area is relatively large, and the deviation of the circumferential magnetic pole intensity distribution after adjustment is still relatively large, at 3.81%;

[0109] It can be seen from Comparative Example 4 and Example 2 that each magnetic pole is adjusted only once for a relatively long time, and the stability and control accuracy are poor. The deviation of the circumferential magnetic pole intensity distribution after adjustment is higher than that before adjustment, which is 17.9%;

[0110] It can be seen from Comparative Example 5 and Example 2 that the magnetic field strength applied during each adjustment is relatively large, resulting in excessive changes in the magnetization state of the magnetic ring. After the adjustment, the deviation of the circumferential magnetic pole intensity distribution is still relatively large, at 3.99%;

[0111] It can be seen from Comparative Example 6 and Example 2 that the heating temperature is too high, resulting in poor control accuracy. After adjustment, the deviation of the circumferential magnetic pole intensity distribution is still relatively large, at 7.28%.

[0112] In summary, the technology of the present invention can be used to effectively adjust the magnetic ring with poor uniformity of the magnetic pole magnetic field, control the deviation of the magnetic pole strength of the radiation-oriented magnetic ring, improve the uniformity of the magnetic ring, and prepare a high-uniformity magnetic ring through the composite regulation of the local magnetization state to meet the application requirements of high magnetic pole strength consistency.

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for adjusting the uniformity of magnetic field intensity of a radiation-oriented magnetic ring pole, characterized in that: In an open circuit environment, the magnetic field strength of the magnetic poles of the magnetic ring is locally adjusted in sequence. The adjustment method is to apply a regulating magnetic field to the magnetic pole at a local position of a single magnetic pole and heat the surface area of ​​the magnetic pole to a certain temperature.

2. The adjustment method according to claim 1, characterized in that: The order of adjustment is to adjust the magnetic field strength of each magnetic pole in order from large to small according to the difference between the magnetic field strength of the magnetic pole and the target value.

3. The adjustment method according to claim 1, characterized in that: The local position of the single magnetic pole is the peak area of ​​each magnetic pole, and the polar angle width included is no more than 20°.

4. The adjustment method according to claim 1, characterized in that: The magnitude of the magnetic field applied during the adjustment process is no greater than 5000Gs, and the distance from the surface of the magnetic ring is no greater than 0.5mm.

5. The adjustment method according to claim 1, characterized in that: The adjustment temperature range during the adjustment process is 150~400℃, and the temperature action area is no larger than 1mm 2 , single time is no more than 3s.

6. The adjustment method according to claim 2, characterized in that: The number of local adjustments of the magnetic field strength of each magnetic pole is greater than 1, and the range of the single adjustment magnetic pole difference is 1 to 70Gs.

7. The adjustment method according to claim 1, characterized in that: Before the uniformity adjustment of the magnetic field strength of the magnetic ring poles is carried out, the magnetic ring is subjected to unipolar radiation orientation magnetization or multipolar radiation orientation magnetization, and the magnetic ring is placed in the corresponding orientation magnetic field for saturation magnetization. After magnetization, the magnetic field strength of the magnetic ring poles is 1000-5000Gs, and the deviation range of each magnetic pole strength is 2-15%.

8. The adjustment method according to claim 1, characterized in that: The method for locally adjusting the magnetic field strength of the magnetic ring poles is applicable to the following magnetic ring size characteristics: the axial height of the magnetic ring is not less than 1 mm, the radius of the magnetic ring is in the range of 5 to 30 mm, and the ratio of the inner and outer diameters is 0.55 to 0.

95.

9. The adjustment method according to claim 8, characterized in that: The method for locally adjusting the magnetic field strength of the magnetic ring pole is applicable to a magnetic ring made of permanent magnetic material, with a coercive force of not less than 10 kOe and a magnetic energy product of not less than 10 MGOe.

10. The adjustment method according to claim 1, characterized in that: After adjustment, the uniformity of the magnetic field intensity distribution of the magnetic ring poles is less than 2%.

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