Permanent magnet ferrite wet pressing magnetic tile mold

Abstract

This invention relates to the field of permanent magnet ferrite product manufacturing technology, specifically disclosing 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, and an arc-shaped top surface and a water-drawing groove. The mold of 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 product demolding, and lowers the frequency of edge cracks in the product.

Description

Technical Field

[0001] This invention belongs to the field of permanent magnet ferrite product manufacturing technology, specifically relating to a wet-pressed permanent magnet ferrite tile mold. Background Technology

[0002] Materials that can respond to a magnetic field in a certain way are called magnetic materials. Based on the strength of their magnetism in an external magnetic field, materials can be classified into diamagnetic, paramagnetic, ferromagnetic, antiferromagnetic, and ferrimagnetic materials. Most materials are diamagnetic or paramagnetic, and their response to external magnetic fields is relatively weak. Ferromagnetic and ferrimagnetic materials are strongly magnetic materials; the term "magnetic material" usually refers to strongly magnetic materials.

[0003] Motor magnet tiles are a type of tile-shaped magnet primarily used in permanent magnet motors. Magnet tiles are mainly used in permanent magnet DC motors. Unlike electromagnetic motors, which generate a magnetomotive force source through excitation coils, permanent magnet motors generate a constant magnetomotive force source using permanent magnet materials. Replacing electrical excitation with permanent magnet tiles offers many advantages, including simpler motor structure, easier maintenance, lighter weight, smaller size, higher reliability, less copper usage, lower copper consumption, and lower energy consumption.

[0004] Currently, most permanent magnet ferrite tile products are arc-shaped with high arc height and large curvature. The tiles are prone to blade cracking during mold forming and pressing, which places high demands on mold processing precision and press debugging, making it difficult to meet the requirements for large-scale stable production of ferrite products.

[0005] As the requirements for ferrite products become increasingly stringent, the problem of blade cracks that easily occur during the molding and pressing of magnetic tiles also needs to be addressed. Customers cannot accept products with cracks, and products with cracks are prone to further cracking during assembly and use.

[0006] Existing magnetic tile molds generally employ a design where the outer arc and the chord width intersect directly. After the product is pressed and formed, stress is generated during demolding, making the joint prone to knife-edge cracks. This results in low product yield and high production costs. Therefore, this application proposes a wet-pressing mold for permanent magnet ferrite magnetic tiles. Summary of the Invention

[0007] The purpose of this invention is to provide a permanent magnet ferrite wet-pressed magnetic tile mold to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a wet pressing mold for permanent magnet ferrite tiles, comprising a middle mold, an upper mold, and a lower punch;

[0009] The middle mold is provided with an outer arc, a beveled edge, and a plane. The middle mold has a cavity and an injection port.

[0010] The upper mold is provided with an outer arc, an outer arc inclined side, and an upper mold plane. The upper mold is provided with an arc-shaped top surface and a water-pumping groove.

[0011] The lower die is provided with a lower die arc surface and a lower die sealing groove.

[0012] Preferably, the outer arc of the middle mold and the inclined side of the outer arc of the middle mold are smoothly connected by the transition fillet of the middle mold.

[0013] Preferably, the chord width surface at the cavity intersects with the outer arc inclined side of the middle mold, the included angle between the chord width surface of the cavity and the outer arc inclined side of the middle mold is 60°-75°, the length of the outer arc inclined side of the middle mold is 5-10mm, and the height of the chord width surface at the cavity exceeding the transition fillet of the middle mold is 1-2mm.

[0014] Preferably, the outer arc of the upper mold and the inclined side of the outer arc of the upper mold are smoothly connected by the transition fillet of the upper mold.

[0015] Preferably, the water pumping tank is arranged around the arc-shaped top surface.

[0016] Preferably, a rubber sealing ring is installed in the sealing groove of the lower punch.

[0017] Preferably, the size of the transition fillet of the intermediate mold is R3-R6.

[0018] Preferably, the upper mold has an outer arc and an outer arc bevel. The outer arc of the upper mold is offset by 0.6-1.2 mm from the outer arc of the middle mold. The outer arc bevel of the upper mold is offset by 0.6-1.2 mm from the outer arc bevel of the middle mold. The transition fillet of the upper mold is offset by 0.6-1.2 mm from the transition fillet of the middle mold.

[0019] Preferably, when the upper mold and the middle mold are fitted together, there is a gap between the upper mold and the middle mold, the gap distance is 0.6-1.2mm, and the gap distance matches the thickness of the filter paper / filter cloth.

[0020] Preferably, after the middle mold, upper mold, and lower punch are assembled, the arc surface of the lower punch, the inner wall of the cavity, and the arc-shaped top surface surround each other to form a molding cavity, the injection port is connected to the molding cavity, and the water extraction tank is connected to the molding cavity.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] I. The mold in this invention includes a middle mold, an upper mold, and a lower punch. The middle mold, upper mold, and lower punch are connected in a combined manner. Before green blank production, the middle mold, upper mold, and lower punch need to be assembled together. During the assembly process, the upper mold needs to be aligned with the middle mold through the outer arc of the upper mold, the inclined edge of the outer arc of the upper mold, the transition rounded corner of the upper mold, and the plane of the upper mold in sequence. The lower punch is inserted into the middle mold. The fit between the upper mold and the middle mold is good, the raw material is not easy to leak, the stress during the product demolding process is small, and the frequency of knife edge cracks in the product is reduced.

[0023] II. After the upper mold and middle mold of this invention are assembled, the four lower punches are respectively inserted into the four cavities in the middle mold. At this time, the arc surface of the lower punch, the inner wall of the cavity, and the arc-shaped top surface surround to form a molding cavity. The injection port is connected to the molding cavity, and the raw material enters the molding cavity from the injection port. Excess raw material is discharged through the water tank. The raw material in the molding cavity is solidified in the molding cavity, and finally a green blank is obtained. The middle mold in the mold is provided with four cavities. A single mold assembly can produce up to four green blanks. The connection between the middle mold, upper mold, and lower punches is stable, and the fit at the connection position is good. This can effectively improve the difficulty of press debugging, increase the yield rate, and reduce costs.

[0024] Third, the lower die of this invention is provided with a lower die sealing groove, in which a rubber sealing ring is installed. A cowhide can be installed in the lower die sealing groove to replace the rubber sealing ring. The cowhide serves the same purpose as the rubber sealing ring: to prevent leakage of the molding slurry. The lower die sealing groove is located on the lower side of the molding cavity, below the injection port. Most of the material entering from the injection port enters the molding cavity, while some flows to the lower die sealing groove. The rubber sealing ring installed in the lower die sealing groove blocks the downward flow channel from the injection port, preventing a large amount of material from being discharged. A water-drawing groove surrounds the arc-shaped top surface. When material enters the molding cavity, it fills the entire cavity. Excess material enters the water-drawing groove and is discharged through it. In this way, excess material injected into the molding cavity can be extracted, ensuring that the amount of material in the molding cavity remains within a specified value. The formed ceramic tile blank will not dent or collapse, and the resulting blank will have a complete shape and a relatively neat appearance. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the wet-pressed permanent magnet ferrite tile mold in this invention.

[0026] Figure 2 This is a schematic diagram of the structure of the intermediate mold in this invention.

[0027] Figure 3 This is a schematic diagram of the upper mold in this invention.

[0028] Figure 4This is a schematic diagram of the lower punch in this invention.

[0029] In the diagram: 1. Middle mold; 11. Outer arc of middle mold; 12. Beveled edge of outer arc of middle mold; 13. Transition fillet of middle mold; 14. Plane of middle mold; 15. Cavity; 16. Injection port; 2. Upper mold; 21. Outer arc of upper mold; 22. Beveled edge of outer arc of upper mold; 23. Transition fillet of upper mold; 24. Plane of upper mold; 25. Water extraction groove; 26. Arc-shaped top surface; 3. Lower punch; 31. Arc surface of lower punch; 32. Sealing groove of lower punch. Detailed Implementation

[0030] 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.

[0031] Reference Figures 1-4 A permanent magnet ferrite wet pressing mold for magnetic tiles includes a middle mold 1, an upper mold 2, and a lower punch 3; the middle mold 1, upper mold 2, and lower punch 3 are connected in combination, and the middle mold 1, upper mold 2, and lower punch 3 need to be assembled together before green production.

[0032] Motor magnet tiles are a type of tile-shaped magnet primarily used in permanent magnet motors. Magnet tiles are mainly used in permanent magnet DC motors. Unlike electromagnetic motors, which generate a magnetomotive force source through excitation coils, permanent magnet motors generate a constant magnetomotive force source using permanent magnet materials. Replacing electrical excitation with permanent magnet tiles offers many advantages, including simpler motor structure, easier maintenance, lighter weight, smaller size, higher reliability, less copper usage, lower copper consumption, and lower energy consumption.

[0033] The magnetic tiles are formed by molding. After the middle mold 1, upper mold 2 and lower punch 3 in the mold are assembled together, the raw materials are fed into them to produce the product.

[0034] Permanent magnet ferrite tile products are all arc-shaped with high arc height and large curvature. During the molding and pressing of the tiles, the cutting edge is prone to cracking. The requirements for mold processing accuracy and press debugging are very high, which makes it difficult to meet the needs of large-scale stable production of ferrite products. In order to meet the needs of large-scale production of ferrite tiles, this application proposes a wet pressing mold for permanent magnet ferrite tiles.

[0035] Reference Figure 2 The middle mold 1 is provided with an outer arc 11, an outer arc inclined side 12, and a middle mold plane 14. The outer arc 11 and the outer arc inclined side 12 are smoothly connected by a middle mold transition fillet 13. The middle mold 1 is provided with a cavity 15. The chord width surface at the cavity 15 intersects with the outer arc inclined side 12. The cavity 15 is provided with an injection port 16.

[0036] Reference Figure 3 The upper mold 2 is provided with an outer arc 21, an outer arc inclined side 22, and an upper mold plane 24. The outer arc 21 and the outer arc inclined side 22 are smoothly connected by an upper mold transition fillet 23. The upper mold 2 is provided with a water drainage groove 25 for draining the green blank. The upper mold 2 is provided with an arc-shaped top surface 26, and the water drainage groove 25 is arranged around the arc-shaped top surface 26.

[0037] Reference Figure 4 The lower die 3 is provided with a lower die arc surface 31 and a lower die sealing groove 32. A rubber sealing ring is installed in the lower die sealing groove 32. A cowhide can be installed in the lower die sealing groove 32 to replace the rubber sealing ring. The cowhide has the same effect as the rubber sealing ring, which is to prevent the leakage of the molding slurry. The lower die 3 is inserted into the cavity 15. The lower die 3 and the cavity 15 can slide freely up and down. In this way, the assembly and separation of the middle die 1 and the lower die 3 are completed.

[0038] The outer arc 11 of the middle mold intersects with the inclined side 12 of the outer arc of the middle mold, and the two are naturally transitioned through the transition fillet 13 of the middle mold. The size of the transition fillet 13 of the middle mold is R3-R6 (i.e., the diameter is 3-6mm). The middle mold 1 is provided with a middle mold plane 14 and a cavity 15. The cavity 15 is provided with an injection port 16. The chord width surface of the cavity 15 intersects with the inclined side 12 of the outer arc of the middle mold. The included angle between the chord width surface of the cavity 15 and the inclined side 12 of the outer arc of the middle mold is 60°-75°. The length of the inclined side 12 of the outer arc of the middle mold is 5-10mm. The height of the chord width surface of the cavity 15 beyond the transition fillet 13 of the middle mold is 1-2mm.

[0039] The upper mold 2 is provided with an outer arc 21 and an outer arc inclined side 22. The outer arc 21 of the upper mold is offset by 0.6-1.2mm parallel to the outer arc 11 of the middle mold, and the outer arc inclined side 22 of the upper mold is offset by 0.6-1.2mm parallel to the outer arc inclined side 12 of the middle mold.

[0040] The outer arc 21 of the upper mold intersects with the inclined side 22 of the outer arc of the upper mold, and the two are naturally transitioned through the transition fillet 23 of the upper mold. The transition fillet 23 of the upper mold is offset by 0.6-1.2mm in parallel with the transition fillet 13 of the middle mold.

[0041] The upper mold 2 has an upper mold plane 24 that intersects with the outer arc inclined edge 22 of the upper mold. The upper mold 2 is provided with a water-drawing groove 25 at the position corresponding to the middle cavity 15 of the middle mold 1. The water-drawing groove 25 is used for drainage of the green blank.

[0042] The mold includes a middle mold 1, an upper mold 2, and a lower punch 3. The middle mold 1, upper mold 2, and lower punch 3 are connected in combination. Before the production of the green blank, the middle mold 1, upper mold 2, and lower punch 3 need to be assembled together. During the assembly process, the upper mold 2 needs to be aligned with the middle mold outer arc 11, middle mold outer arc inclined edge 22, upper mold transition fillet 23, and upper mold plane 24 in sequence. The upper mold 2 has a good fit with the middle mold 1, the middle mold outer arc inclined edge 12, the middle mold transition fillet 13, and the middle mold plane 14. The fit between the upper mold 2 and the middle mold 1 is good, the raw material is not easy to leak, the stress during the product demolding process is small, and the frequency of knife edge cracks in the product is reduced.

[0043] The lower die 3 is provided with a lower die arc surface 31, and a lower die sealing groove 32 is machined around it. A leather or rubber sealing ring is installed at the lower die sealing groove 32. The leather or rubber sealing ring is used to prevent leakage of the molding slurry. The lower die 3 is installed in the cavity 15 inside the middle die 1, and the lower die 3 and the cavity 15 can slide freely up and down.

[0044] During molding and pressing, the upper mold 2 matches the middle mold's outer arc 11, outer arc bevel 22, transition fillet 23, and plane 24 through the upper mold's outer arc 21, outer arc bevel 22, transition fillet 13, and plane 14. Specifically, the upper mold 2 corresponds one-to-one with the middle mold's outer arc 11, outer arc bevel 12, transition fillet 13, and plane 14 through the upper mold's outer arc 21, outer arc bevel 22, transition fillet 23, and plane 24. When the upper mold 2 and the middle mold 1 are engaged, there is a gap between them, with a gap distance of 0.6-1.2mm. This gap distance matches the thickness of the filter paper / filter cloth. The filter paper / filter cloth is used to filter the moisture in the slurry, allowing the green body to be formed, removing excess moisture from the raw material, and allowing the raw material to solidify inside the molding cavity. The raw material is finally solidified into a green body.

[0045] After the middle mold 1, upper mold 2, and lower punch 3 are assembled, the lower punch arc surface 31, the inner wall of the cavity 15, and the arc-shaped top surface 26 surround each other to form a molding cavity. The injection port 16 is connected to the molding cavity, and the raw material enters the molding cavity from the injection port 16. Excess raw material is discharged through the water extraction tank 25, that is, the water extraction tank 25 is connected to the molding cavity.

[0046] The lower die 3 is provided with a lower die sealing groove 32, and a rubber sealing ring is installed in the lower die sealing groove 32. A cowhide can be installed in the lower die sealing groove 32 to replace the rubber sealing ring. The cowhide has the same effect as the rubber sealing ring, which is to prevent the leakage of molding slurry. The lower die sealing groove 32 is located on the lower side of the molding cavity and on the lower side of the injection port 16. Most of the raw material entering from the injection port 16 enters the molding cavity, and some raw material flows to the position of the lower die sealing groove 32. The rubber sealing ring is installed in the lower die sealing groove 32 to block the channel of the injection port 16 flowing downward and prevent a large amount of raw material from being discharged.

[0047] During the forming of the magnetic tile, the arc surface 31 of the lower punch 3 fits with the structure of the bottom of the magnetic tile blank, while the arc-shaped top surface 26 fits with the structure of the top of the magnetic tile blank. The inner wall of the cavity 15 fits with the structure of the side of the magnetic tile blank. Together, they form a shaping cavity with the same shape as the magnetic tile blank, thereby pressing the magnetic tile blank.

[0048] The arc-shaped top surface 26 is surrounded by a water extraction tank 25. The raw material enters the molding cavity and fills the entire molding cavity. Excess raw material enters the interior of the water extraction tank 25 and is discharged through it. In this way, excess raw material injected into the molding cavity can be extracted to ensure that the amount of raw material in the molding cavity is kept within the specified value, so that the formed magnetic tile blank will not sink or collapse.

[0049] The green blank is produced by pressing the material through the injection port 16 when the upper die 2, middle die 1, and lower punch 3 are in operation.

[0050] Working principle:

[0051] The mold includes a middle mold 1, an upper mold 2, and a lower punch 3. The middle mold 1, upper mold 2, and lower punch 3 are connected in combination. Before the production of the green blank, the middle mold 1, upper mold 2, and lower punch 3 need to be assembled together. During the assembly process, the upper mold 2 needs to be aligned with the middle mold outer arc 11, middle mold outer arc inclined edge 22, upper mold transition rounded corner 23, and upper mold plane 24 in sequence. The upper mold 2 has a good fit with the middle mold 1, the middle mold outer arc inclined edge 12, the middle mold transition rounded corner 13, and the middle mold plane 14. The fit between the upper mold 2 and the middle mold 1 is good, the raw material is not easy to leak, the stress during the product demolding process is small, and the frequency of knife edge cracks in the product is reduced.

[0052] After the upper mold 2 and the middle mold 1 are assembled, the four lower punches 3 are inserted into the four cavities 15 in the middle mold 1 respectively. At this time, the arc surface 31 of the lower punch, the inner wall of the cavity 15, and the arc-shaped top surface 26 surround each other to form a plastic cavity. The injection port 16 is connected to the plastic cavity. The raw material enters the plastic cavity from the injection port 16. The excess raw material is discharged through the water tank 25. The raw material in the plastic cavity is solidified in the plastic cavity, and finally a green blank is obtained. The middle mold 1 in the mold is provided with four cavities 15. A single mold assembly can produce a maximum of four green blanks.

[0053] 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 mold for wet pressing permanent magnet ferrite tiles, comprising a middle mold (1), an upper mold (2), and a lower punch (3); The middle mold (1) is provided with a middle mold outer arc (11), a middle mold outer arc inclined side (12), and a middle mold plane (14). The middle mold (1) is provided with a cavity (15), and the cavity (15) is provided with an injection port (16). The upper mold (2) is provided with an upper mold outer arc (21), an upper mold outer arc inclined side (22), and an upper mold plane (24). The upper mold (2) is provided with an arc-shaped top surface (26) and a water-drawing groove (25). The lower die (3) is provided with a lower die arc surface (31) and a lower die sealing groove (32). The outer arc (11) of the middle mold and the inclined side (12) of the outer arc of the middle mold are smoothly connected by the transition fillet (13) of the middle mold; The chord width surface at the cavity (15) intersects with the outer arc inclined side (12) of the middle mold. The included angle between the chord width surface of the cavity (15) and the outer arc inclined side (12) of the middle mold is 60°-75°. The length of the outer arc inclined side (12) of the middle mold is 5-10mm. The height of the chord width surface at the cavity (15) beyond the transition fillet (13) of the middle mold is 1-2mm. The outer arc (21) of the upper mold and the inclined side (22) of the outer arc of the upper mold are smoothly connected by the transition fillet (23) of the upper mold; Its features are: The upper mold (2) is provided with an outer arc (21) and an outer arc bevel (22). The outer arc (21) of the upper mold is offset by 0.6-1.2 mm relative to the outer arc (11) of the middle mold. The outer arc bevel (22) of the upper mold is offset by 0.6-1.2 mm relative to the outer arc bevel (12) of the middle mold. The transition fillet (23) of the upper mold is offset by 0.6-1.2 mm relative to the transition fillet (13) of the middle mold.

2. The permanent magnet ferrite wet-pressed magnetic tile mold according to claim 1, characterized in that, The water pumping tank (25) is arranged around the arc-shaped top surface (26).

3. The permanent magnet ferrite wet-pressed magnetic tile mold according to claim 1, characterized in that, A rubber sealing ring is installed in the lower die sealing groove (32).

4. The permanent magnet ferrite wet-pressed magnetic tile mold according to claim 1, characterized in that, The size of the intermediate mold transition fillet (13) is R3-R6.

5. A permanent magnet ferrite wet-pressed magnetic tile mold according to claim 1, characterized in that, When the upper mold (2) and the middle mold (1) are fitted together, there is a gap between the upper mold (2) and the middle mold (1), and the gap distance is 0.6-1.2mm. The gap distance is matched with the thickness of the filter paper and filter cloth.

6. The permanent magnet ferrite wet-pressed magnetic tile mold according to claim 1, characterized in that, After the middle mold (1), upper mold (2), and lower punch (3) are combined, the lower punch arc surface (31), the inner wall of the cavity (15), and the arc-shaped top surface (26) surround each other to form a plastic cavity. The injection port (16) is connected to the plastic cavity, and the water tank (25) is connected to the plastic cavity.

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