A magnet surface treatment device, system and surface treatment method of NdFeB magnet

Abstract

The present invention relates to a magnet surface treatment device, system and method for surface treatment of NdFeB magnets. The magnet surface treatment device of the present invention comprises: a main shaft and a spiral rotating channel wound on the main shaft; the main shaft is used to provide support; the spiral rotating channel is spirally wound on the main shaft and is used to load and transport magnets. The method is to place the NdFeB magnet in the spiral rotating device channel, and under the action of the main shaft vibration system and gravity, the NdFeB magnet slides from the top of the spiral rotating device channel to the bottom under the full immersion of the treatment liquid, thereby completing the surface treatment. The NdFeB magnet surface treatment device and system of the present invention occupy a small area and greatly improve the production efficiency while ensuring good cleaning and passivation film quality. A single device can achieve the cleaning and passivation requirements of NdFeB magnets of any size and shape.

Description

Technical Field

[0001] The invention belongs to the field of magnet surface treatment, and relates to a magnet surface treatment device, a system and a surface treatment method for NdFeB magnets, and is particularly suitable for automatic line surface treatment of magnets of different sizes and shapes in batches. Background Art

[0002] In recent years, the market demand and industrial scale of sintered NdFeB permanent magnet materials are developing rapidly, and its application fields cover many industries such as modern home appliances, industrial motors, microelectronic motors, new energy vehicles, etc. However, there are certain disadvantages in its promotion. These magnetic materials are easily corroded in the process of contact with air and moisture, resulting in changes in performance, so surface treatment is essential.

[0003] The surface treatment of NdFeB magnets mainly includes the degreasing, pickling, washing and passivation processes of surface pretreatment, as well as subsequent electroplating, spraying, vacuum coating, etc. The core of NdFeB magnet surface treatment technology is equipment and methods. The existing magnet surface treatment devices are mainly rollers and hangers.

[0004] Drum processing is mainly suitable for small magnet products. It has the advantages of easy loading and unloading and high production efficiency. However, it is easy to knock the edges during the production process, and the appearance is uneven after surface treatment. It is also unable to process thin sheets and larger magnet products. Hanging parts are mainly suitable for the surface treatment of large magnet products. It has the advantages of no knocking the edges during the production process and uniform appearance after surface treatment, but the production efficiency is low. Although the surface treatment devices using drums and hanging parts can solve the surface treatment of most products, there are still some magnet products in the actual production process that cannot be treated by any of the above surface treatment methods alone, or the treatment efficiency is low, or the defective rate is high after treatment, such as smaller thin sheet magnet products and thicker magnet products. Different magnet products need to be equipped with different surface treatment devices, which increases production and management costs.

[0005] For example, patent document CN106148927 discloses a device and method for surface treatment of a large-size magnet roller; patent document CN106435678B discloses a surface treatment method for a specific roller equipped with steel balls; patent document CN207537583U discloses a special tool for plating large-size NdFeB magnets. The above-mentioned treatment devices or treatment methods cannot meet the surface treatment requirements of NdFeB magnets of any size and shape, and it is difficult to improve the surface treatment efficiency and reduce the defective rate caused by surface treatment. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides:

[0007] A magnet surface treatment device comprises a main shaft and a spiral rotation channel wound around the main shaft.

[0008] According to an embodiment of the present invention, the main shaft is used to provide support.

[0009] According to an embodiment of the present invention, the spiral turning channel is spirally wound on the main shaft and is used for loading and transporting magnets.

[0010] According to an embodiment of the present invention, the spiral turning channel is spiral. Preferably, the present invention has no particular limitation on the number of turns of the spiral turning channel, which can be reasonably designed according to the demand for the magnets to be surface treated. Preferably, the number of turns is 1-5 turns.

[0011] According to an embodiment of the present invention, a channel inlet and a channel outlet are provided on the spiral turning channel, and in the vertical direction, the channel inlet is higher than the channel outlet.

[0012] Preferably, the channel inlet and the channel outlet are respectively arranged near the two ends of the spiral turning channel. As an example, when the inner diameter of each circle of the spiral turning channel gradually increases from top to bottom, the channel inlet is arranged near the center of the spiral turning channel, and the channel outlet is at the outermost layer of the channel.

[0013] Preferably, the channel slope of the spiral turning channel is selected from 0-45°, for example, the channel slope is 10°, 15°, 20°, 25°, 30°, 35°, 40° or 45°.

[0014] Preferably, the inner wall material of the spiral turning channel is selected from non-metal composite materials. Preferably, the non-metal composite materials are selected from polyurethane, polytetrafluoroethylene, polypropylene, polyethylene, polyvinyl chloride and polyester polyol.

[0015] Preferably, the spiral turning channel is selected from a closed type or an open type. For example, the cross-sectional shape of the spiral turning channel can be selected from Figure 4 The closed U-shaped or open U-shaped shown. In the present invention, the cross-sectional dimensions of the spiral rotation channel can be arbitrarily designed according to the dimensions of the magnet to be processed.

[0016] Preferably, when the cross-sectional shape of the spiral rotating channel is a closed U-shape or an open U-shape, the inner width of the cross-sectional shape is ≤45 cm, and the height of the cross-sectional shape is ≤25 cm.

[0017] According to the embodiment of the present invention, the present invention has no special requirements on the size and shape of the magnet to be surface treated. For example, the shape of the magnet is selected from rectangular, tile-shaped, dovetail, cylindrical and other special shapes.

[0018] According to an embodiment of the present invention, the spiral rotation channel further includes a transmission medium, and the transmission medium can move in the spiral rotation channel. When the transmission medium and the magnet are in the spiral rotation channel at the same time, the transmission medium can change the residence time of the magnet in the spiral rotation channel.

[0019] Preferably, the residence time of the magnet in the spiral rotation channel can be controlled by controlling the weight ratio, quantity ratio or volume ratio of the magnet to the transmission medium. The present invention has no particular limitation on the quantity ratio of the magnet to the transmission medium, as long as the residence time of the magnet in the spiral rotation channel can be changed by the transmission medium. Exemplarily, the weight ratio of the magnet to the transmission medium is 5:1, 6:1, 10:1, 15:1, 20:1, etc.

[0020] Preferably, the shape of the transmission medium is selected from a sphere.

[0021] Preferably, the diameter of the sphere is smaller than the length of the magnet in any direction. For example, when the magnet is a cube, the diameter of the sphere is smaller than the width or height of the cuboid; when the magnet is an irregular shape, the diameter of the sphere is smaller than the length of the magnet in any direction.

[0022] Preferably, the transmission medium is selected from acid-resistant and alkali-resistant wear-resistant materials. Preferably, the density of the transmission medium is selected from 2 to 4×10 3 kg / m 3 .

[0023] Exemplarily, the transmission medium is selected from at least one of glass balls, zirconia balls, alumina balls, and the like.

[0024] According to an embodiment of the present invention, the surface treatment device further includes a vibration unit.

[0025] Preferably, the vibration unit is connected to the main shaft, and the spiral rotation channel can vibrate under the action of the vibration unit. When the magnet enters the spiral rotation channel, the residence time of the magnet in the spiral rotation channel is controlled by adjusting the vibration frequency of the vibration unit, and the vibration of the vibration unit can prevent the patches between the magnets from sticking together, so that the surface of the magnet is fully processed.

[0026] Preferably, the vibration unit in the present invention can be a vibration unit commonly used in the technical field, as long as it can provide vibration power to make the magnet vibrate in the channel. For example, a vibrator with a vibration frequency of 0-50 Hz can be provided.

[0027] According to an embodiment of the present invention, when the spiral rotating channel is transmitting the magnet, the residence time of the magnet in the spiral rotating channel can be controlled by at least one of the magnet's own gravity, vibration unit, transmission medium, channel slope and flow rate of the treatment liquid.

[0028] According to an embodiment of the present invention, a heat-insulating layer is further provided on the outer side of the spiral turning channel.

[0029] Preferably, the thermal insulation layer includes a thermal insulation material. The present invention does not specifically limit the thermal insulation material, as long as the thermal insulation function of the thermal insulation layer can be achieved. The present invention provides a thermal insulation layer on the outside of the spiral rotation channel, and the surface treatment device can be used for surface treatment such as cleaning and passivation of the magnet under high temperature and normal temperature conditions.

[0030] According to an embodiment of the present invention, a circular hole is further provided at the channel outlet, and when the treatment liquid flows along the spiral rotation channel to the channel outlet, it can be separated from the magnet through the circular hole. Preferably, the diameter of the circular hole is smaller than the diameter of the transmission medium.

[0031] According to an embodiment of the present invention, a vibration sorting screen unit is further provided at the end of the channel outlet. When the magnet and the transmission medium enter the vibration sorting screen unit, the transmission medium falls to the bottom of the vibration sorting screen unit after screening, thereby achieving separation of the magnet and the transmission medium.

[0032] The present invention also provides a magnet surface treatment system, the surface treatment system comprises a magnet surface treatment device, and the magnet surface treatment device has the meaning as described above.

[0033] According to an embodiment of the present invention, the surface treatment system further comprises a treatment liquid recovery device.

[0034] Preferably, the treatment liquid recovery device is located between the treatment liquid storage tank and the channel outlet, and the treatment liquid can flow into the treatment liquid recovery device through the circular hole at the channel outlet. The present invention does not specifically limit the treatment liquid recovery unit, as long as the treatment liquid can be recovered.

[0035] According to an embodiment of the present invention, the surface treatment system further comprises a treatment liquid device.

[0036] Preferably, the treatment liquid device comprises a treatment liquid storage tank, and the treatment liquid storage tank is connected to the channel inlet and the treatment liquid recovery device respectively, for example, they can be connected through a treatment liquid pipeline.

[0037] Preferably, the treatment liquid storage tank is further provided with a heating unit to heat the treatment liquid in the treatment liquid storage tank.

[0038] Preferably, the treatment liquid device is further provided with a filter unit, and the filter unit is provided between the treatment liquid storage tank and the channel inlet. The present invention does not specifically limit the filter unit, as long as it can filter the treatment liquid. Preferably, the filter unit can be a filter unit commonly used in the technical field, for example, the filter unit is a filter.

[0039] According to an embodiment of the present invention, the surface treatment system further comprises a pre-cleaning device connected to the channel inlet.

[0040] According to an embodiment of the present invention, the surface treatment system further comprises an ultrasonic cleaning device, which is connected to the vibration sorting screen unit and can ultrasonically clean the magnet after the surface treatment again.

[0041] According to an embodiment of the present invention, the surface treatment system further comprises a curing device, which is connected to the ultrasonic cleaning device. After the magnet is ultrasonically cleaned, curing is completed in the curing device.

[0042] Preferably, the curing device is selected from an oven, a drying tunnel, and the like.

[0043] According to an embodiment of the present invention, the surface treatment system further comprises a return device. The return device is arranged between the vibration sorting screen unit and the channel entrance. When the transmission medium falls to the bottom of the vibration sorting screen unit after screening, the return device can transmit the transmission medium to the channel entrance and re-enter the spiral rotation channel of the surface treatment device.

[0044] According to an embodiment of the present invention, the pre-cleaning device, the surface treatment device, the ultrasonic cleaning device, the curing device, the treatment liquid device and the return device are respectively controlled by a control power supply.

[0045] The present invention also provides application of the magnet surface treatment device or the magnet surface treatment system in surface treatment of NdFeB magnets.

[0046] The present invention also provides a surface treatment method for a NdFeB magnet, wherein the surface treatment method adopts the surface treatment device or the surface treatment system for treatment.

[0047] According to an embodiment of the present invention, the surface treatment method comprises the following specific steps:

[0048] Step 1, start the vibration unit;

[0049] Step 2, introducing the treatment liquid and the rotating medium into the spiral rotating channel;

[0050] Step 3, placing the NdFeB magnet to be processed at the entrance of the spiral rotation channel;

[0051] Step 4: The NdFeB magnet is surface treated in the spiral rotation channel.

[0052] According to an embodiment of the present invention, the treatment time of the magnet in the channel is 0.2-15 min, for example, 0.5 min, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min.

[0053] Preferably, the processing time can be adjusted and controlled by at least one of the following methods: the vibration frequency of the vibration unit, the flow rate of the processing liquid, the channel slope, or the mass ratio, quantity ratio or volume ratio of the magnet to the transmission medium.

[0054] According to an embodiment of the present invention, the transmission medium has the definition as described above.

[0055] According to an embodiment of the present invention, the vibration frequency of the vibration unit is controlled within a range of 0-50 Hz.

[0056] According to an embodiment of the present invention, the flow rate of the treatment liquid can be controlled by the treatment liquid device. Preferably, the flow rate of the treatment liquid is 10-50 L / min, for example, 30 L / min, 35 L / min, 40 L / min.

[0057] According to an embodiment of the present invention, the channel slope has the definition as described above.

[0058] According to an embodiment of the present invention, the quality, quantity or volume of the transmission medium can be controlled by the return device.

[0059] According to an embodiment of the present invention, the treatment liquid is selected from any one of an acidic solution, an alkaline solution, water or a passivation solution. Depending on the treatment liquid, various functions such as cleaning or surface passivation of the magnet surface can be achieved. Preferably, the treatment liquid is selected from a zinc phosphating solution or a silane conversion solution. Preferably, the pH value of the treatment liquid is selected from 1-13, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or an interval value between any two of the above values.

[0060] According to an embodiment of the present invention, the treatment liquid may be heated by a heating unit.

[0061] Preferably, the temperature of the treatment liquid is selected from 0-100° C. Preferably, the temperature of the treatment liquid is selected from 20-80° C. Exemplarily, the temperature of the treatment liquid is 10° C., 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C. or an interval value between any two of the above values.

[0062] According to an embodiment of the present invention, the NdFeB magnet to be treated is also pre-cleaned before surface treatment.

[0063] Preferably, the present invention does not specifically limit the pre-cleaning method, which can be determined according to the conditions of the NdFeB magnets to be processed.

[0064] According to an embodiment of the present invention, the NdFeB magnet is further subjected to ultrasonic cleaning after the surface treatment.

[0065] Preferably, the present invention does not specifically limit the method of ultrasonic cleaning, and it can be selected according to the commonly used methods in the technical field.

[0066] According to an embodiment of the present invention, the NdFeB magnet is further subjected to a curing treatment after being ultrasonically cleaned.

[0067] Preferably, the present invention does not impose any specific restrictions on the time and temperature of the curing treatment, as long as the curing of the magnet after the surface treatment can be achieved.

[0068] Preferably, the curing treatment includes blowing and drying. For example, the drying temperature is 105° C., and the curing treatment time is 30 minutes.

[0069] The beneficial effects of the present invention are:

[0070] The magnet surface treatment device and system provided by the present invention change the traditional surface treatment method of rollers or hangers. By setting a spiral rotating channel, there is no special requirement for the shape of the magnet product, the passivation and cleaning effects are good, and the magnet steel will not leave passivation and cleaning dead corners.

[0071] The magnet surface treatment device and system provided by the present invention occupy a small area and can meet the surface cleaning and passivation requirements of NdFeB magnets of different sizes and shapes. While ensuring good cleaning and passivation film quality, the production efficiency is greatly improved. A single device can achieve the cleaning and passivation requirements of NdFeB magnets of any size and shape, and is particularly suitable for automatic lines that perform surface treatment on magnets in batches.

[0072] By adopting the surface treatment method of the present invention, the flow rate of the treatment liquid, the frequency of the vibration unit, the channel slope and the transmission medium are matched with each other, so that the magnet and the treatment liquid can be fully in contact with each other. The surface of the treated magnet has good uniformity and no patch marks, and products of any size and shape with different treatment times can be treated. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a structural schematic diagram of a magnet surface treatment device of the present invention;

[0074] Figure 2 It is a top view of the spiral rotation channel;

[0075] Figure 3 It is a schematic diagram of the entrance structure of the spiral rotation channel;

[0076] Figure 4 A cross-sectional view of a U-shaped or U-shaped spiral rotating channel;

[0077] The reference numerals have the following meanings: 1. pre-cleaning device; 2. channel entrance; 3. spiral rotating channel; 4. channel exit; 5. circular hole; 6. control power supply; 7. vibration unit; 8. vibration sorting screen; 9. return device; 10. treatment liquid recovery device; 11. treatment liquid storage tank; 12. heating system; 13. filter; 14. treatment liquid pipeline; 15. ultrasonic cleaning; 16. curing device; 17. insulation layer. DETAILED DESCRIPTION

[0078] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0079] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0080] In a specific embodiment of the present invention, Figure 1 , Figure 2 and Figure 3 As shown, a magnet surface treatment system of the present invention includes a pre-cleaning device 1, a magnet surface treatment device and a curing device 16.

[0081] In a specific embodiment of the present invention, Figure 2 and Figure 3 As shown, the magnet surface treatment device includes a main shaft and a spiral rotation channel 3, wherein the spiral rotation channel 3 is spirally wound on the main shaft. For example, the main shaft is located as shown in FIG. Figure 2The spiral rotating channel 3 is provided with a channel inlet 2 and a channel outlet 4, and a circular hole 5 is also provided on the channel outlet 4. The magnet surface treatment device also includes a vibration unit 7 and a vibration sorting screen 8. Preferably, a heat preservation layer 17 is also provided on the outer side of the spiral rotating channel 3.

[0082] In a specific embodiment of the present invention, Figure 1 As shown, the magnet surface treatment system also includes a control power supply 6, a feedback device 9, a treatment liquid recovery device 10, a treatment liquid device, an ultrasonic cleaning device 15, and a curing device 16.

[0083] In a specific embodiment of the present invention, Figure 1 As shown, the treatment liquid device comprises a treatment liquid storage tank 11, a heating unit 12, and a filter 13. Preferably, the treatment liquid device is connected to the treatment liquid recovery device 10 and the channel inlet 2 through a treatment liquid pipeline 14, respectively.

[0084] In a specific embodiment of the present invention, in the above-mentioned surface treatment system, a high temperature or room temperature phosphorus-free passivation liquid or an acidic or alkaline cleaning agent is used to perform surface passivation treatment on the surface of the NdFeB magnet. The specific steps of the surface treatment method are as follows:

[0085] (1) First, the treatment liquid heating system 12 is started by controlling the power supply 6, and the treatment liquid is heated to a desired temperature (e.g., 55° C.), and then the vibration unit 7, the vibration sorting screen 8, the return device 9 and the ultrasonic cleaning 15 are started, and the filter 13 is started;

[0086] (2) The treated liquid reaching a certain temperature passes through the filter 13 and the treated liquid pipeline 14 to reach the channel inlet 2, flows along the spiral rotating channel 3 to the channel outlet 4 under the action of gravity, and flows back to the treated liquid storage tank 11 through the circular hole 5 at the channel outlet 4 and the treated liquid recovery device 10 to form a filtering cycle;

[0087] (3) The transmission medium is screened by the vibrating sorting screen 8, falls to the bottom of the vibrating sorting screen 8, is transported back to the channel inlet 2 through the return device 9, and under the action of the vibration unit 7, rolls down to the channel outlet 4 through the spiral rotating channel 3, and falls back to the vibrating sorting screen 8;

[0088] (4) After the magnetic steel is pre-cleaned by the pre-cleaning device 1, it is transferred to the channel entrance 2 through the conveyor belt, and falls into the channel entrance 2 together with the treatment liquid and the transmission medium. The treatment liquid fully immerses the magnetic steel and the transmission medium. Under the action of the vibration unit 7 and gravity, the transmission medium rolls down along the spiral rotating channel 3. The outer side of the spiral rotating channel 3 is provided with an insulation layer 17, which can achieve the insulation effect of the treatment liquid in the spiral rotating channel 3. The transmission medium drives the magnetic steel to slide along the channel 3 to the channel outlet 4, and the treatment liquid flows back to the treatment liquid storage tank 11 through the circular hole 5; the magnetic steel and the transmission medium flow to the vibration sorting screen 8, and after screening, the transmission medium falls to the bottom of the vibration sorting screen 8, and then is returned to the channel entrance 2 through the return device 9; the magnetic steel passes through the outlet of the vibration sorting screen 8 and falls to the ultrasonic cleaning device 15. After the ultrasonic cleaning, the magnetic steel is solidified by the solidification device 16 to complete the passivation treatment.

[0089] Example 1

[0090] The magnet is phosphated by the surface treatment method, wherein the spiral channel 3 is a U-shaped polyurethane (sectional view as shown in FIG. Figure 4 As shown in the middle right figure), the slope is 15°, the magnet to be treated is a rectangular parallelepiped with a single weight of 396g; the treatment liquid is a zinc-based phosphating liquid, the treatment temperature is 55°C, the phosphating liquid flow rate is 40L / min, the transmission medium is spherical glass beads with a diameter of 8-10mm, the mass ratio of the magnet to the transmission medium is 6:1, the magnet stays in the channel for 10min, and after screening, the magnet enters a water washing tank and an ultrasonic cleaning tank for cleaning, and finally is blown dry and dried. The magnet is first blown through with hot air at a certain temperature, and then dried at 105°C*30min to obtain a magnet after phosphating treatment.

[0091] The phosphating film on the surface of the magnet after phosphating treatment was analyzed by EDS-7200 energy spectrometer for surface appearance and composition. The results are as follows: the film layer is uniform and dense; the appearance consistency of the treated magnet is OK when observed with the naked eye, without scratches and chipped edges; the 5% sodium chloride neutral salt spray is qualified after 60 minutes, and rusts after 70 minutes; the 85℃ and 85% wet heat test is qualified after 300 minutes, and rusts after 330 minutes.

[0092] Example 2

[0093] The above-mentioned surface treatment method is used to perform phosphating treatment on the magnet, wherein the channel of the spiral rotation channel 3 is a U-shaped polyurethane with a slope of 15°; the magnet to be treated is a C-shaped tile with a single weight of 3.5g; the treatment liquid is a zinc-based phosphating solution, the treatment temperature is 55°C, the phosphating solution flow rate is 30L / min, the transmission medium is spherical zirconia with a diameter of 3-5mm, the mass ratio of the magnet to the transmission medium is 10:1, the magnet stays in the channel for 10min, and after screening, the magnet enters a water washing tank and an ultrasonic cleaning tank for cleaning, and finally is blown dry and dried, firstly the magnet is blown through with hot air at a certain temperature, and then dried at 105°C*30min to obtain a magnet after phosphating treatment.

[0094] The phosphating film on the surface of the magnet after phosphating treatment was analyzed by EDS-7200 energy spectrometer for surface appearance and composition. The results are as follows: the film layer is uniform and dense; the appearance consistency of the treated magnet is OK when observed with the naked eye, without scratches and chipped edges; the magnet is qualified after 40 minutes of 5% sodium chloride neutral salt spray, and rusts after 50 minutes; the 85℃ and 85% wet heat test is qualified after 300 minutes, and rusts after 330 minutes.

[0095] Example 3

[0096] The magnet is subjected to silane conversion treatment using the above surface treatment method, wherein the channel of the spiral turning channel 3 is a U-shaped polyurethane (sectional view as shown in FIG. Figure 4 As shown in the middle left figure), the slope is 30°, the magnet to be treated is a rectangular parallelepiped with a single weight of 15.7g; the treatment liquid is a silane conversion liquid, the treatment temperature is room temperature, the conversion liquid flow rate is 35L / min, the transmission medium is spherical glass beads with a diameter of 5-7mm, the mass ratio of magnet to transmission medium is 5:1, the magnet stays in the channel for 3min, and after screening, the magnet enters a water washing tank for cleaning, and finally is blown dry and dried. The magnet is first blown with hot air at a certain temperature, and then dried at 105℃*30min to obtain a magnet after silane conversion treatment.

[0097] The conversion film on the surface of the magnet after silane conversion treatment was measured by EDS-7200 energy spectrometer for surface appearance and composition, and the results were as follows: the film layer was uniform and dense; the magnet after treatment was observed with the naked eye, and the appearance consistency was OK, without scratches and chipped edges; the magnet passed the 5% sodium chloride neutral salt spray test after 20 minutes, and rusted after 30 minutes; the 85℃ and 85% wet heat test passed after 150 minutes, and rusted after 180 minutes.

[0098] Example 4

[0099] The above-mentioned surface treatment method is used to perform phosphating treatment on the magnet, wherein the channel of the spiral rotation channel 3 is a U-shaped polyurethane with a slope of 30°; the magnet to be treated is a D-shaped tile with a single weight of 4.2g; the treatment liquid is a zinc-based phosphating solution, the treatment temperature is 55°C, the phosphating solution flow rate is 30L / min, the transmission medium is spherical glass beads with a diameter of 3-5mm, the mass ratio of the magnet to the transmission medium is 10:1, the magnet stays in the channel for 5min, and after screening, the magnet enters a water washing tank and an ultrasonic cleaning tank for cleaning, and finally is blown dry and dried, firstly the magnet is blown through with hot air at a certain temperature, and then dried at 105°C*30min to obtain a magnet after phosphating treatment.

[0100] The phosphating film on the surface of the magnet after phosphating treatment was analyzed by EDS-7200 energy spectrometer. The results showed that the film layer was uniform and dense. The magnet after treatment was observed with naked eyes, and the appearance consistency was OK, without scratches and chipped edges. The magnet passed the test in 5% sodium chloride neutral salt spray after 40 minutes, and rusted after 50 minutes. The magnet passed the test in 85℃ and 85% wet heat test after 240 minutes, and rusted after 270 minutes.

[0101] Example 5

[0102] The above-mentioned surface treatment method is used to perform silane conversion treatment on the magnet, wherein the channel of the spiral rotation channel 3 is U-shaped polyurethane with a slope of 40°, the magnet to be treated is dovetail-shaped, and the single weight is 10.2g; the treatment liquid is silane conversion liquid, the treatment temperature is room temperature, the conversion liquid flow rate is 35L / min, the transmission medium is spherical zirconia with a diameter of 5-7mm, the mass ratio of the magnet to the transmission medium is 5:1, the magnet stays in the channel for 2min, and after screening, the magnet enters a water washing tank for cleaning, and finally is blown dry and dried, firstly the magnet is blown through with hot air at a certain temperature, and then dried at 105℃*30min to obtain the magnet after silane conversion treatment.

[0103] The conversion film on the surface of the magnet after silane conversion treatment was analyzed by EDS-7200 energy spectrometer for surface appearance and composition. The results are as follows: the film layer is uniform and dense; the appearance consistency of the treated magnet is OK when observed with the naked eye, without scratches and chipped edges; the magnet is qualified after 30 minutes of 5% sodium chloride neutral salt spray, and rusts after 40 minutes; the magnet is qualified after 180 minutes of 85℃ and 85% wet heat test, and rusts after 210 minutes.

[0104] The exemplary embodiments of the present invention are described above. However, the present invention is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnet surface treatment system, characterized in that: The surface treatment system comprises a magnet surface treatment device, which comprises a main shaft and a spiral rotation channel wound around the main shaft; The main shaft is used to provide support; the spiral rotation channel is spirally wound on the main shaft and is used to load and transport magnets; the spiral rotation channel is spiral, and the inner diameter of each circle of the spiral rotation channel from top to bottom gradually increases; the channel slope of the spiral rotation channel is selected from 0-45°; a channel entrance and a channel exit are arranged on the spiral rotation channel, and in the vertical direction, the channel entrance is higher than the channel exit; the channel entrance and the channel exit are respectively arranged near the two ends of the spiral rotation channel, the channel entrance is arranged near the center of the spiral rotation channel, and the channel exit is at the outermost layer of the channel; The surface treatment device further comprises a vibration unit; the vibration unit is connected to the main shaft, and the spiral rotation channel vibrates under the action of the vibration unit; The spiral rotation channel also includes a transmission medium, and the transmission medium moves in the spiral rotation channel; the shape of the transmission medium is selected from a sphere; the diameter of the sphere is smaller than the length of the magnet in any direction; A circular hole is also provided at the outlet of the channel; the diameter of the circular hole is smaller than the diameter of the transmission medium; The surface treatment system further comprises a treatment liquid recovery device and a treatment liquid device; the treatment liquid device comprises a treatment liquid storage tank; the treatment liquid recovery device is located between the treatment liquid storage tank and the channel outlet, and the treatment liquid flows into the treatment liquid recovery device through the circular hole at the channel outlet; The treatment liquid is selected from any one of an acidic solution, an alkaline solution, water, and a silane conversion liquid.

2. The magnet surface treatment system according to claim 1, characterized in that The inner wall material of the spiral rotation channel is selected from non-metal composite materials; the non-metal composite materials are selected from polyurethane, polytetrafluoroethylene, polypropylene, polyethylene, polyvinyl chloride and polyester polyol; The spiral turning channel is selected from a closed type or an open type; the cross-sectional shape of the spiral turning channel is selected from a closed U-shaped or an open U-shaped.

3. The magnet surface treatment system according to claim 1, characterized in that: The weight ratio of the magnet to the transmission medium is 6:1, 10:1, 15:1, 20:1; The transmission medium is selected from acid-resistant and alkali-resistant wear-resistant materials; the density of the transmission medium is selected from 2~4×10 3 kg / m 3 .

4. The magnet surface treatment system according to claim 1, characterized in that: A heat-insulating layer is also provided on the outer side of the spiral rotating channel; The thermal insulation layer comprises thermal insulation material; A vibrating sorting screen unit is also arranged at the end of the channel outlet.

5. The magnet surface treatment system according to claim 1, characterized in that: The treatment liquid storage tank is connected to the channel inlet and the treatment liquid recovery device respectively; The treatment liquid storage tank is also provided with a heating unit to heat the treatment liquid in the treatment liquid storage tank; The treatment liquid device is further provided with a filter unit, and the filter unit is arranged between the treatment liquid storage tank and the channel inlet.

6. The magnet surface treatment system according to claim 1, characterized in that: The treatment liquid storage tank is connected to the channel inlet and the treatment liquid recovery device respectively through a treatment liquid pipeline.

7. The magnet surface treatment system according to claim 4, characterized in that: The surface treatment system further comprises a pre-cleaning device, wherein the pre-cleaning device is connected to the channel inlet; The surface treatment system also includes an ultrasonic cleaning device, which is connected to the vibration sorting screen unit; The surface treatment system further comprises a curing device, which is connected to the ultrasonic cleaning device; The curing device is selected from an oven and a drying tunnel; The surface treatment system further comprises a return device; the return device is arranged between the vibration sorting screen unit and the channel entrance.

8. The magnet surface treatment system according to claim 1, characterized in that: The treatment liquid is selected from a passivation liquid.

9. The magnet surface treatment system according to claim 1, characterized in that: The treatment liquid is selected from zinc phosphating liquid.

10. Use of the magnet surface treatment system according to any one of claims 1 to 9 in surface treatment of NdFeB magnets.

11. A surface treatment method for a neodymium iron boron magnet, characterized in that: The surface treatment method adopts the magnet surface treatment system described in any one of claims 1-9 for treatment.

12. The surface treatment method according to claim 11, characterized in that: The surface treatment method comprises the following specific steps: Step 1, start the vibration unit; Step 2, introducing the treatment liquid and the transmission medium into the spiral rotation channel; Step 3, placing the NdFeB magnet to be processed at the entrance of the spiral rotation channel; Step 4: The NdFeB magnet is surface treated in the spiral rotation channel.

13. The surface treatment method of NdFeB magnet according to claim 12, characterized in that: The treatment time of the magnet in the channel is 0.2-15min; The treatment time is adjusted and controlled by at least one of the following methods: the vibration frequency of the vibration unit, the flow rate of the treatment liquid, the channel slope, or the mass ratio, quantity ratio, or volume ratio of the magnet to the transmission medium; The vibration frequency of the vibration unit is controlled at 0-50 Hz; The flow rate of the treatment liquid is controlled by the treatment liquid device; the flow rate of the treatment liquid is 10-50L / min; The treatment liquid is selected from any one of an acidic solution, an alkaline solution, water, and a silane conversion liquid; The treatment liquid is heated by a heating unit; The temperature of the treatment liquid is selected from 0-100°C; The NdFeB magnets to be treated are also pre-cleaned before surface treatment; After surface treatment, the NdFeB magnets are also ultrasonically cleaned; After ultrasonic cleaning, the NdFeB magnet is also subjected to a curing treatment; the curing treatment includes blowing and baking.

14. The surface treatment method of NdFeB magnet according to claim 11, characterized in that: The temperature of the treatment liquid is selected from 20-80° C.; the treatment liquid is selected from passivation liquid.

15. The surface treatment method of NdFeB magnet according to claim 11, characterized in that: The treatment liquid is selected from zinc phosphating liquid.

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