Magnetic shoe mold for improving mechanical strength of permanent magnetic ferrite and implementation method of magnetic shoe mold

Abstract

The invention discloses a magnetic shoe mold for improving mechanical strength of permanent magnetic ferrite, which comprises a middle mold body, an upper mold body is arranged above the middle mold body, a lower mold body is arranged in the middle mold body, a cavity is arranged between the lower mold body and the upper mold body, a water suction tank is arranged above the upper mold body, and a plurality of first water suction holes penetrating through the upper mold body are arranged in the water suction tank. The arrangement number of the first water suction holes is sequentially increased from the center position of the water suction groove to the two sides, and at least one water pumping hole communicated with the water suction groove is further formed in the upper die body. The invention further discloses an implementation method of the magnetic shoe mold for improving the mechanical strength of the permanent magnetic ferrite. A plurality of first water absorption holes penetrating through the upper die body are formed in the water absorption tank, and the arrangement number of the first water absorption holes is sequentially increased from the center position of the water absorption tank to the two sides of the water absorption tank, so that the density of the middle and the two sides of a formed magnetic shoe is more uniform, and the problem of heating subfissure or cooling subfissure during sintering of the magnetic shoe is avoided; the mechanical strength of the magnetic tile is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of permanent magnet ferrite molds, and particularly relates to a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite and an implementation method thereof. BACKGROUND

[0002] Permanent magnet ferrite magnets are core materials for manufacturing high-efficiency energy-saving permanent magnet motors, can realize efficient energy conversion, are of great significance to improving motor efficiency and realizing energy saving and emission reduction, and are widely used in new energy vehicles, white goods, intelligent manufacturing and other fields. Due to the design needs of rotating motors, whether as a stator or as a rotor, permanent magnet ferrite magnets are mostly designed in the shape of tiles, referred to as magnetic tiles.

[0003] A permanent magnet DC motor needs a few pieces of permanent magnet ferrite tiles, and a few tens of pieces of permanent magnet ferrite tiles. With the continuous improvement of the miniaturization and energy saving needs of permanent magnet motors, the performance requirements of permanent magnet ferrite tiles are getting higher and higher, and the volume, especially the thickness, is getting smaller and smaller, so the requirement for the compressive strength of the magnetic tile under the same conditions is getting higher and higher. If the mechanical strength is not enough, the magnetic tile may break or crack during the magnetizing or using process of the motor, which may cause the motor rotor to be stuck, resulting in serious consequences. Therefore, the mechanical strength of the magnetic tile must be controlled during the production process to ensure that the strength of the magnetic tile meets the requirements.

[0004] Chinese Patent Application No. 202411722162.6 discloses a manufacturing method for improving the strength of wet-pressed magnetic tiles of permanent magnet ferrite; including the following production steps: step one: weighing the iron red with appropriate particle size, strontium carbonate with appropriate particle size and additives, mixing uniformly, pre-burning to obtain pre-burning material magnetic powder; step two: putting the pre-burning material magnetic powder together with sintering additives into a ball mill for micro-pulverization with water as the medium; step three: adjusting the water content of the micro-pulverized slurry, shaping in a magnetic field to obtain a magnetic tile pressing blank; step four: placing the magnetic tile pressing blank in a kiln for sintering to obtain a sintered magnetic tile semi-finished product. Step five: grinding the sintered magnetic tile semi-finished product. The present application uses iron red with a particle size greater than or equal to 1.5 μm to produce ferrite pre-burning material, and controls the fine grinding particle size of the slurry before wet pressing to be greater than 0.8 μm, so that the mechanical strength of the wet-pressed magnetic tile obtained by sintering is significantly improved.

[0005] The above-mentioned disclosed patent uses coarse particle size iron red in the preparation of pre-burning material; and controls the fine grinding particle size to be greater than 0.8 μm in the fine grinding stage, so that the temperature resistance of the product is significantly improved, the product is not easy to crystallize, the brittleness of the product is greatly reduced, and the strength of the product is improved. Although the mechanical strength of the magnetic tile is improved, the improvement is made on the raw materials.

[0006] Chinese Patent Application No. 201520651450.7 discloses a magnetic tile mold with an outer arc working surface, belonging to the field of magnetic tile molds. It solves the problems of existing magnetic tile molds with outer arc working surfaces having relatively complex structures, high operating costs, and low-quality produced magnetic tiles. This utility model includes a punch, a die, and a water-absorbing plate. The upper end of the punch has an inwardly recessed outer arc surface; the outer arc surface has a lower non-magnetic layer; the lower non-magnetic layer is an arc-shaped layer made of non-magnetic stainless steel; the die has a cavity corresponding to the shape of the punch; the lower surface of the water-absorbing plate has an outwardly protruding inner arc surface; the inner arc surface has an upper non-magnetic layer; the upper non-magnetic layer is made of non-magnetic stainless steel, and its surface shape corresponds to that of the lower non-magnetic layer. This utility model has a simple structure, low manufacturing and operating costs, long service life, and produces high-quality magnetic tiles, effectively obtaining magnetic tiles with a high magnetic field difference between the inner and outer arc surfaces.

[0007] The aforementioned patent aims to address the problems of relatively complex insert structures on punches, easy breakage during the stamping process, high usage costs in mass production, and poor performance of weakly magnetic materials.

[0008] Chinese patent application number 202411994165.5 discloses a wet-pressed permanent magnet ferrite tile mold, including a middle mold, an upper mold, and a lower die. The middle mold has an outer arc, an outer arc bevel, and a plane, and a cavity with a material injection port. The upper mold has an outer arc, an outer arc bevel, and a plane, an arc-shaped top surface, and a water-drawing groove. The mold in this invention includes a middle mold, an upper mold, and a lower die. During assembly, the upper mold aligns sequentially with the middle mold through its outer arc, outer arc bevel, transition fillet, and plane. The lower die is inserted into the middle mold. The good fit between the upper and middle molds prevents material leakage, reduces stress during demolding, and lowers the frequency of edge cracks in the product.

[0009] The aforementioned patent aims to solve the problem that stress is generated during the demolding process after the product is pressed and molded, which easily leads to knife-edge cracks at the junction and a low product qualification rate.

[0010] Therefore, there is an urgent need for a magnetic tile mold that can improve the mechanical strength of permanent magnet ferrite. By optimizing the structure of the permanent magnet ferrite mold, the mechanical strength of the permanent magnet ferrite magnetic tile can be improved. Summary of the Invention

[0011] The purpose of this invention is to provide a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, thereby solving the problems mentioned in the background art. The magnetic tile mold provided by this invention improves the mechanical strength of permanent magnet ferrite by making the density of the permanent magnet ferrite tiles more uniform, thus enhancing the mechanical strength of the product.

[0012] Another objective of this invention is to provide a method for realizing a magnetic tile mold that improves the mechanical strength of permanent magnet ferrite.

[0013] To achieve the above objectives, the present invention provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, comprising a middle mold body, an upper mold body above the middle mold body, a lower mold body inside the middle mold body, a cavity between the lower mold body and the upper mold body, a water absorption groove above the upper mold body, a plurality of first water absorption holes penetrating the upper mold body in the water absorption groove, the number of first water absorption holes increasing sequentially from the center of the water absorption groove to both sides, and at least one water extraction hole communicating with the water absorption groove on the upper mold body.

[0014] Furthermore, in this invention, the middle mold body, the upper mold body, and the lower mold body are all made of highly magnetically conductive material.

[0015] In this invention, the inner diameter of the upper end of the first water-absorbing hole is 3-5 mm, and the inner diameter of the lower end of the first water-absorbing hole is 1-2 mm.

[0016] To increase the water absorption rate on both sides during the forming of the magnetic tile and thus reduce the density difference, a ring of second water absorption holes in a rectangular pattern is further provided on the outer side of several first water absorption holes. The inner diameter of the second water absorption holes is 3-5mm.

[0017] To effectively reduce water return from the upper mold body and decrease the density difference of the magnetic tiles, the bottom of the water absorption groove is further designed with a convex arc shape.

[0018] In order to increase the pressure after sealing the mold, it can effectively prevent the slurry from running out, thereby reducing the density difference between the two sides and the middle of the magnetic tile. Furthermore, inclined platforms are provided on both sides of the protrusion of the middle mold body.

[0019] To make the magnetic field lines of the magnetic tile more evenly distributed and less prone to cracking, a non-magnetic insert is provided at the upper end of the lower mold body. The thickness of the non-magnetic insert in the middle is equal to the thickness on both sides.

[0020] To optimize the distribution of magnetic lines of force and make the magnetic forces in the upper, middle and lower directions of the magnetic tile closer together, the upper end of the lower mold body is further provided with a horizontal arc-shaped protrusion, and the bottom surface of the non-magnetic insert fits into the arc-shaped protrusion.

[0021] Furthermore, in this invention, the method for implementing a magnetic tile mold to enhance the mechanical strength of permanent magnet ferrite includes the following steps:

[0022] (i) A water absorption groove is set above the upper mold body. The water absorption groove is provided with a number of first water absorption holes that penetrate the upper mold body. The number of first water absorption holes increases from the center of the water absorption groove to both sides.

[0023] (ii) A ring of second water-absorbing holes arranged in a rectangular pattern is provided on the outside of several first water-absorbing holes;

[0024] (iii) At least one water extraction hole communicating with the water absorption tank shall be provided on the upper mold body;

[0025] (iv) Inclined platforms are provided on both sides of the protrusion of the middle mold body;

[0026] (v) A non-magnetic insert is provided at the upper end of the lower mold body, and the thickness of the middle part of the non-magnetic insert is equal to the thickness of the two sides.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. The present invention has a number of first water absorption holes penetrating the upper mold body in the water absorption tank. The number of first water absorption holes increases from the center of the water absorption tank to both sides, so that the density of the middle and both sides of the magnetic tile after molding is more uniform, thereby avoiding the problem of heat-induced microcracks or cooling-induced microcracks in the magnetic tile during sintering and improving the mechanical strength of the magnetic tile.

[0029] 2. The present invention has two water extraction holes on the upper mold body that are connected to the water absorption groove, which reduces the backflow of water in the upper mold body and thus reduces the density difference of the magnetic tiles.

[0030] 3. The present invention provides a ring of second water-absorbing holes arranged in a rectangular pattern on the outside of several first water-absorbing holes. By setting the second water-absorbing holes, the water absorption speed on both sides during the forming of the magnetic tile is increased, thereby reducing the density difference of the magnetic tile.

[0031] 4. The bottom of the water absorption tank of the present invention has a convex arc-shaped structure, and the height difference between the high end and the low end of the bottom of the water absorption tank is greater than 2mm. By setting the bottom of the water absorption tank to have a convex arc-shaped structure, with the middle position being high and the two ends being low, the water return phenomenon of the upper mold body is effectively reduced, and the density difference of the magnetic tile is reduced.

[0032] 5. The present invention provides inclined platforms on both sides of the protrusion of the middle mold body, which increases the pressure after the mold is sealed and can effectively prevent the slurry from running out, thereby reducing the density difference between the two sides and the middle of the magnetic tile.

[0033] 6. The upper end of the lower mold body of the present invention is provided with a non-magnetic insert. The non-magnetic insert is made of non-magnetic stainless steel. The thickness of the middle position of the non-magnetic insert is equal to the thickness of the two sides, which reduces the thickness of the two sides of the non-magnetic insert, thereby making the magnetic lines of force of the magnetic tile more uniform and less prone to cracking.

[0034] 7. The upper end of the lower mold body of the present invention is provided with a horizontal arc-shaped protrusion. The bottom surface of the non-magnetic insert fits with the arc-shaped protrusion, which optimizes the distribution of magnetic lines of force and makes the magnetic force of the magnetic tile in the upper, middle and lower directions closer.

[0035] 8. This invention redesigns and optimizes the structure of the middle mold body, upper mold body, and lower mold body, making the density of the magnetic tiles more uniform, thereby effectively improving the mechanical strength of the magnetic tiles. Attached Figure Description

[0036] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0037] Figure 2 This is a cross-sectional view of the upper mold body of the present invention.

[0038] Figure 3 This is a top view of the structure of the upper mold body of the present invention.

[0039] Figure 4 This is a top view of the upper mold body in the prior art of this invention.

[0040] Figure 5 This is a cross-sectional view of the phantom in this invention.

[0041] Figure 6 This is a cross-sectional view of the phantom body in the prior art of this invention.

[0042] Figure 7 This is a schematic diagram of the structure of the lower mold body of the present invention.

[0043] Figure 8 This is a schematic diagram of the structure of the lower mold body in the prior art of this invention.

[0044] Figure 9 For the present invention Figure 7 A side view of the structure.

[0045] In the diagram: 1. Middle mold body; 101. Inclined platform; 2. Upper mold body; 21. Water suction groove; 22. First water suction hole; 23. Water extraction hole; 24. Second water suction hole; 3. Cavity; 4. Lower mold body; 41. Non-magnetic insert; 42. Arc-shaped protrusion. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] In the description of this invention, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used merely for distinction in description and have no special meaning.

[0050] Example 1

[0051] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, comprising a middle mold body 1, which is made of pure iron; an upper mold body 2, also made of pure iron, is provided above the middle mold body 1; a lower mold body 4, also made of pure iron, is provided inside the middle mold body 1. Under the action of a certain external magnetic field, the magnetic tile is magnetized through the upper mold body 2, the middle mold body 1, and the lower mold body 4 to form a circuit, thereby achieving a pre-magnetization effect; a cavity 3 is provided between the lower mold body 4 and the upper mold body 2. A water-absorbing groove 21 is provided on the upper part of the upper mold body 2. The water-absorbing groove 21 is provided with a number of first water-absorbing holes 22 penetrating the upper mold body 2. The distance between two adjacent first water-absorbing holes 22 is 4-10mm, preferably 4mm in this embodiment. The number of first water-absorbing holes 22 increases from the center of the water-absorbing groove 21 to both sides. The upper mold body 2 is also provided with two water-drawing holes 23 communicating with the water-absorbing groove 21. The inner diameter of the upper end of the first water-absorbing hole 22 is 3mm, and the inner diameter of the lower end of the first water-absorbing hole 22 is 1mm.

[0052] By adopting the above technical solution, this invention provides a plurality of first water-absorbing holes 22 penetrating the upper mold body 2 within the water-absorbing groove 21. The number of first water-absorbing holes 22 increases sequentially from the center of the water-absorbing groove 21 towards both sides, making the density of the middle and sides of the formed magnetic tile more uniform. This avoids the problem of heat-induced microcracks or cooling-induced microcracks in the magnetic tile during sintering, thereby improving the mechanical strength of the magnetic tile. This invention also provides two water-drawing holes 23 on the upper mold body 2 that communicate with the water-absorbing groove 21, reducing water return in the upper mold body 2 and thus reducing the density difference of the magnetic tile. By redesigning and optimizing the structure of the middle mold body 1, the upper mold body 2, and the lower mold body 4, this invention makes the density of the magnetic tile more uniform, thereby effectively improving the mechanical strength of the magnetic tile.

[0053] Example 2

[0054] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, comprising a middle mold body 1, which is made of pure iron; an upper mold body 2, also made of pure iron, is provided above the middle mold body 1; and a lower mold body 4, also made of pure iron, is provided inside the middle mold body 1. Under the action of a certain external magnetic field, the upper mold body 2, the middle mold body 1, and the lower mold body 4 magnetize the magnetic tile to form a circuit, thereby achieving a pre-magnetization effect. The lower mold body 4 and the upper mold body 2... The mold has a cavity 3 and a water absorption groove 21 on the upper part of the upper mold body 2. The water absorption groove 21 has several first water absorption holes 22 that penetrate the upper mold body 2. The distance between two adjacent first water absorption holes 22 is 7mm. The number of first water absorption holes 22 increases from the center of the water absorption groove 21 to both sides. The upper mold body 2 also has two water extraction holes 23 that communicate with the water absorption groove 21. The inner diameter of the upper end of the first water absorption hole 22 is 4mm and the inner diameter of the lower end of the first water absorption hole 22 is 1.5mm.

[0055] Specifically, a ring of second water-absorbing holes 24 arranged in a rectangular pattern is provided on the outer side of several first water-absorbing holes 22, and the inner diameter of the second water-absorbing holes 24 is 3mm.

[0056] By adopting the above technical solution and setting the second water absorption hole 24, the water absorption speed on both sides during the forming of the magnetic tile is increased, thereby reducing the density difference of the magnetic tile.

[0057] Example 3

[0058] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, including a middle mold body 1, which is made of pure iron. An upper mold body 2, also made of pure iron, is provided above the middle mold body 1. A lower mold body 4, also made of pure iron, is provided inside the middle mold body 1. A cavity 3 is provided between the lower mold body 4 and the upper mold body 2. A water absorption groove 21 is provided above the upper mold body 2. Several first water absorption holes 22 penetrating the upper mold body 2 are provided in the water absorption groove 21. The distance between two adjacent first water absorption holes 22 is 10mm. The number of first water absorption holes 22 increases sequentially from the center of the water absorption groove 21 to both sides. The upper mold body 2 is also provided with two water extraction holes 23 communicating with the water absorption groove 21. The inner diameter of the upper end of the first water absorption hole 22 is 5mm, and the inner diameter of the lower end of the first water absorption hole 22 is 2mm.

[0059] Specifically, a ring of second water-absorbing holes 24 arranged in a rectangular pattern is provided on the outer side of several first water-absorbing holes 22, and the inner diameter of the second water-absorbing holes 24 is 4mm. By adopting the above technical solution, the water absorption speed on both sides during the forming of the magnetic tile is increased by setting the second water-absorbing holes 24, thereby reducing the density difference of the magnetic tile.

[0060] Specifically, the bottom of the water absorption tank 21 has a convex arc-shaped structure, and the height difference between the high end and the low end of the bottom of the water absorption tank 21 is greater than 2mm, preferably 2.5mm in this embodiment.

[0061] By adopting the above technical solution, the bottom of the water absorption tank 21 is set to a convex arc structure, with the middle position being high and the two ends being low, thereby effectively reducing the water return phenomenon of the upper mold body 2 and reducing the density difference of the magnetic tiles.

[0062] Example 4

[0063] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, including a middle mold body 1, which is made of pure iron. An upper mold body 2 is provided above the middle mold body 1, which is also made of pure iron. A lower mold body 4 is provided inside the middle mold body 1. Under the action of a certain external magnetic field, the magnetic tile is magnetized through the upper mold body 2, the middle mold body 1, and the lower mold body 4 to form a circuit, thereby achieving the effect of pre-magnetization. The lower mold body 4 is made of pure iron. A cavity 3 is provided between the lower mold body 4 and the upper mold body 2. A water absorption groove 21 is provided above the upper mold body 2. Several first water absorption holes 22 penetrating the upper mold body 2 are provided in the water absorption groove 21. The number of first water absorption holes 22 increases from the center of the water absorption groove 21 to both sides. The upper mold body 2 is also provided with two water extraction holes 23 that communicate with the water absorption groove 21. The inner diameter of the upper end of the first water absorption hole 22 is 5mm, and the inner diameter of the lower end of the first water absorption hole 22 is 2mm.

[0064] Specifically, a ring of second water-absorbing holes 24 arranged in a rectangular pattern is provided on the outer side of several first water-absorbing holes 22, and the inner diameter of the second water-absorbing holes 24 is 5mm. By adopting the above technical solution, the water absorption speed on both sides during the forming of the magnetic tile is increased by setting the second water-absorbing holes 24, thereby reducing the density difference of the magnetic tile.

[0065] Specifically, inclined platforms 101 are provided on both sides of the protrusion of the middle mold body 1. The width b of the inclined platform 101 is 6-15mm, preferably 7mm in this embodiment, and the height a of the inclined platform 101 is 2-6mm, preferably 4mm in this embodiment.

[0066] By adopting the above technical solution, the present invention provides inclined platforms 101 on both sides of the protrusion of the middle mold body 1, which increases the pressure after sealing the mold and can effectively prevent slurry leakage, thereby reducing the density difference between the two sides and the middle of the magnetic tile.

[0067] Example 5

[0068] Please see Figure 1 , Figure 2 ,Figure 3 , Figure 4 , Figure 7 and Figure 8 This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, including a middle mold body 1, which is made of pure iron. An upper mold body 2 is provided above the middle mold body 1, which is also made of pure iron. A lower mold body 4 is provided inside the middle mold body 1. Under the action of a certain external magnetic field, the magnetic tile is magnetized through the upper mold body 2, the middle mold body 1, and the lower mold body 4 to form a circuit, thereby achieving the effect of pre-magnetization. The lower mold body 4 is made of pure iron. A cavity 3 is provided between the lower mold body 4 and the upper mold body 2. A water absorption groove 21 is provided above the upper mold body 2. Several first water absorption holes 22 penetrating the upper mold body 2 are provided in the water absorption groove 21. The number of first water absorption holes 22 increases from the center of the water absorption groove 21 to both sides. The upper mold body 2 is also provided with two water extraction holes 23 that communicate with the water absorption groove 21. The inner diameter of the upper end of the first water absorption hole 22 is 5mm, and the inner diameter of the lower end of the first water absorption hole 22 is 2mm.

[0069] Specifically, the upper end of the lower mold body 4 is provided with a non-magnetic insert 41. The non-magnetic insert 41 is made of non-magnetic stainless steel, and the thickness of the middle part of the non-magnetic insert 41 is equal to the thickness of the two sides.

[0070] By adopting the above technical solution, the thickness on both sides of the non-magnetic insert 41 is reduced, thereby making the magnetic field lines of the magnetic tile more uniformly distributed and less prone to cracking.

[0071] Example 6

[0072] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 7 and Figure 9 This embodiment provides the following technical solution: a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, including a middle mold body 1, which is made of pure iron. An upper mold body 2 is provided above the middle mold body 1, which is also made of pure iron. A lower mold body 4 is provided inside the middle mold body 1. Under the action of a certain external magnetic field, the magnetic tile is magnetized through the upper mold body 2, the middle mold body 1, and the lower mold body 4 to form a circuit, thereby achieving the effect of pre-magnetization. The lower mold body 4 is made of pure iron. A cavity 3 is provided between the lower mold body 4 and the upper mold body 2. A water absorption groove 21 is provided above the upper mold body 2. Several first water absorption holes 22 penetrating the upper mold body 2 are provided in the water absorption groove 21. The number of first water absorption holes 22 increases from the center of the water absorption groove 21 to both sides. The upper mold body 2 is also provided with two water extraction holes 23 that communicate with the water absorption groove 21. The inner diameter of the upper end of the first water absorption hole 22 is 5mm, and the inner diameter of the lower end of the first water absorption hole 22 is 2mm.

[0073] Specifically, a non-magnetic insert 41 is provided at the upper end of the lower mold body 4. The non-magnetic insert 41 improves the direction of the magnetic lines of force. The non-magnetic insert 41 is made of non-magnetic stainless steel, and the thickness of the middle part of the non-magnetic insert 41 is equal to the thickness of the two sides. By adopting the above technical solution, the thickness of the two sides of the non-magnetic insert 41 is reduced, thereby making the magnetic lines of force of the magnetic tile more uniform and less prone to cracking.

[0074] Specifically, the upper end of the lower mold body 4 is provided with a horizontal arc-shaped protrusion 42, and the bottom surface of the non-magnetic insert 41 is in contact with the arc-shaped protrusion 42.

[0075] By adopting the above technical solution, the distribution of magnetic field lines is optimized, making the magnetic forces in the upper, middle and lower directions of the magnetic tile closer together.

[0076] Example 7

[0077] Furthermore, the method for implementing a magnetic tile mold to improve the mechanical strength of permanent magnet ferrite, as described in this invention, includes the following steps:

[0078] (i) A water absorption groove 21 is provided above the upper mold body 2. The water absorption groove 21 is provided with a plurality of first water absorption holes 22 penetrating the upper mold body 2. The number of first water absorption holes 22 increases from the center of the water absorption groove 21 to both sides. The distance between two adjacent first water absorption holes 22 is 4-10mm. In this embodiment, it is preferably 5mm.

[0079] (ii) A ring of second water-absorbing holes 24 arranged in a rectangular pattern is provided on the outside of several first water-absorbing holes 22. The inner diameter of the second water-absorbing holes 24 is 3-5mm.

[0080] (iii) At least one water extraction hole 23 communicating with the water absorption groove 21 is provided on the upper mold body 2;

[0081] (iv) Inclined steps 101 are provided on both sides of the protrusion of the middle mold body 1. The width b of the inclined steps 101 is 6-15mm, preferably 7mm in this embodiment, and the height a of the inclined steps 101 is 2-6mm, preferably 4mm in this embodiment.

[0082] (v) A non-magnetic insert 41 is provided at the upper end of the lower mold body 4, and the thickness of the middle position of the non-magnetic insert 41 is equal to the thickness of the two sides.

[0083] Experimental Example

[0084] Ten magnetic tiles were pressed using both existing molds and the mold of this invention, and their strength was tested to obtain the following data:

[0085]

[0086] Based on the table above, it is clear that the strength of the magnetic tiles formed by the mold in this invention is significantly higher than that of the magnetic tiles formed by the mold in the prior art.

[0087] In summary, this invention provides a plurality of first water-absorbing holes 22 penetrating the upper mold body 2 within the water-absorbing groove 21. The number of first water-absorbing holes 22 increases sequentially from the center of the water-absorbing groove 21 towards both sides, making the density of the middle and sides of the formed magnetic tile more uniform. This avoids the problem of heat-induced microcracks or cooling-induced microcracks in the magnetic tile during sintering, thereby improving the mechanical strength of the magnetic tile. This invention also provides two water-drawing holes 23 on the upper mold body 2 that communicate with the water-absorbing groove 21, reducing water return in the upper mold body 2 and thus reducing the density difference of the magnetic tile. Furthermore, this invention provides a ring of second water-absorbing holes 24 arranged in a rectangular pattern outside the plurality of first water-absorbing holes 22. The arrangement of the second water-absorbing holes 24 increases the water absorption speed on both sides during the forming of the magnetic tile, thereby reducing the density difference of the magnetic tile. The bottom of the water-absorbing groove 21 of this invention has a convex arc-shaped structure, and the height difference between the high end and the low end of the bottom of the water-absorbing groove 21 is greater than 2mm. By setting the bottom of the water-absorbing groove 21 to a convex arc-shaped structure, with the middle position being higher and the two ends being lower, the backflow of water in the upper mold body 2 is effectively reduced, and the density difference of the magnetic tiles is reduced. The invention provides inclined platforms 101 on both sides of the protrusion of the middle mold body 1, which increases the pressure after sealing the mold and can effectively prevent slurry leakage, thereby reducing the density difference between the sides and the middle of the magnetic tiles. The upper end of the lower mold body 4 of this invention is provided with a non-magnetic insert 41. The non-magnetic insert 41 is made of non-magnetic stainless steel, and the thickness of the non-magnetic insert 41 in the middle position is equal to the thickness on both sides, reducing the thickness on both sides of the non-magnetic insert 41, thereby making the magnetic lines of force distribution of the magnetic tiles more uniform and less prone to cracking. The lower mold body 4 of this invention has a horizontally oriented arc-shaped protrusion 42 at its upper end. The bottom surface of the non-magnetic insert 41 fits into the arc-shaped protrusion 42, optimizing the distribution of magnetic lines of force and making the magnetic forces in the upper, middle, and lower directions of the magnetic tile more even. By redesigning and optimizing the structure of the middle mold body 1, the upper mold body 2, and the lower mold body 4, this invention makes the density of the magnetic tile more uniform, thereby effectively improving the mechanical strength of the magnetic tile.

[0088] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite, characterized in that: It includes a middle mold body, an upper mold body above the middle mold body, a lower mold body inside the middle mold body, a cavity between the lower mold body and the upper mold body, a water absorption groove above the upper mold body, and a number of first water absorption holes penetrating the upper mold body in the water absorption groove. The number of first water absorption holes increases sequentially from the center of the water absorption groove to both sides. The upper mold body also has at least one water extraction hole that communicates with the water absorption groove.

2. The magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: The middle mold body, upper mold body, and lower mold body are all made of highly magnetically conductive material.

3. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: The inner diameter of the upper end of the first water suction hole is 3-5mm, and the inner diameter of the lower end of the first water suction hole is 1-2mm.

4. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: A ring of second water-absorbing holes arranged in a rectangular pattern is provided on the outer side of several first water-absorbing holes.

5. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 4, characterized in that: The inner diameter of the second water absorption hole is 3-5mm.

6. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: The bottom of the water absorption tank has a convex arc shape.

7. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: The middle mold body has inclined platforms on both sides of the protrusion.

8. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 1, characterized in that: The upper end of the lower mold body is provided with a non-magnetic insert, and the thickness of the middle position of the non-magnetic insert is equal to the thickness of the two sides.

9. A magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to claim 8, characterized in that: The upper end of the lower mold body is provided with a horizontal arc-shaped protrusion, and the bottom surface of the non-magnetic insert is in contact with the arc-shaped protrusion.

10. A method for implementing a magnetic tile mold for improving the mechanical strength of permanent magnet ferrite according to any one of claims 1-9, characterized in that, Includes the following steps: (i) A water absorption groove is set above the upper mold body. The water absorption groove is provided with a number of first water absorption holes that penetrate the upper mold body. The number of first water absorption holes increases from the center of the water absorption groove to both sides. (ii) A ring of second water-absorbing holes arranged in a rectangular pattern is provided on the outside of several first water-absorbing holes; (iii) At least one water extraction hole communicating with the water absorption tank shall be provided on the upper mold body; (iv) Inclined platforms are provided on both sides of the protrusion of the middle mold body; (v) A non-magnetic insert is provided at the upper end of the lower mold body, and the thickness of the middle part of the non-magnetic insert is equal to the thickness of the two sides.

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