A magnetic powder forming mold

Abstract

This utility model relates to a magnetic powder forming mold, including an outer frame and a mold frame disposed within the outer frame; the outer frame is formed by two long side plates and two short side plates; the mold frame is formed by four long and short templates made of tempered mold steel; the inner sides of the long and short templates are provided with cavities, and the outer surfaces of the long and short templates are provided with template connection holes, and the surfaces of the long and short templates are provided with a nitriding layer; the long and short side plates are provided with side plate connection holes, and the side plate connection holes are recessed with groove structures near the inner surfaces. The beneficial effect of this utility model is that the warped edge of the template connection hole after slight deformation after nitriding will be embedded in the groove structure, so that the template and the side plate can fit precisely. This method of creating groove structures on a softer ordinary mold steel outer frame, rather than directly trimming the template after nitriding of 38CrMoAl alloy, reduces the difficulty of mold making and ensures the precision of the mold at a low cost.

Description

Technical Field

[0001] This utility model relates to a magnetic powder forming mold for pressing magnetic powder into magnetic steel. Background Technology

[0002] Magnetic powder die casting is currently the most common method for manufacturing magnets. This method first processes the raw materials for magnet production into powder, then mixes these powders to ensure a uniform distribution of components. Next, the mixed powder is placed in a specific mold for molding, giving it a preliminary magnet shape. Following this, a sintering process is performed at high temperatures to bond the powder particles together, forming a dense magnet structure. Finally, heat treatment further optimizes the internal structure of the magnet, and a magnetization process is completed to give the magnet the magnetic properties required for its application.

[0003] Magnet forming dies are widely used in the manufacturing of permanent magnet materials. They are indispensable for the production of common permanent magnet materials such as ferrite magnets and neodymium iron boron magnets. Magnet products manufactured using these dies are widely used in many important fields, including electronics, power, automotive, and aerospace. For example, in motors, magnets provide the magnetic field to ensure normal operation; in loudspeakers, magnets convert electrical signals into sound signals; and in magnetic separation equipment, magnets are used to separate substances with different magnetic properties.

[0004] There are many types of steel used in molding dies, and those with high strength and performance are relatively expensive. Therefore, we have to adopt steel composite technology, using ordinary mold steel for the outer layer and high-performance steel for the inner layer to manufacture powder molding dies, in order to achieve a compromise between performance and price.

[0005] Nitriding is a common reinforcing process used in forming steel. Nitriding increases hardness, significantly improving the hardness and strength of the mold cavity. In such mold plates, screw holes are usually drilled before nitriding. However, after nitriding, the edges of the screw holes are easily deformed by the process, causing warping and affecting the actual precision of the mold. Utility Model Content

[0006] In order to overcome the shortcomings of the current nitriding process, which makes the magnetic powder forming mold prone to deformation after nitriding and affects the accuracy, this utility model provides a magnetic powder forming mold with a nitrided inner frame.

[0007] The technical solution of this utility model to solve its technical problem is: a magnetic powder forming mold, including an outer frame and a mold frame disposed within the outer frame; the outer frame is formed by two long side plates and two short side plates; the mold frame is formed by four long and short templates made of tempered mold steel, with two long templates and two short templates; the inner sides of the long and short templates are provided with cavities, the outer surfaces of the long and short templates are provided with template connection holes, and the surfaces of the long and short templates are provided with a nitriding layer; the long side plates and short side plates... The long template and the short template are connected together by screws through the template connection hole and the side plate connection hole of the short side plate. The long side plate has a clamping edge protruding inward at its end, and the short side plate has steps on both sides. When the long side plate and the short side plate are connected together by threaded parts, the clamping edge presses on the steps. The long side plate and the short side plate have a groove structure recessed near the inner side at the side plate connection hole position.

[0008] To increase the connection strength between the short template and the long template, shear-resistant grooves are provided on the connection surfaces of the short template and the long template, and shear-resistant columns are provided in the shear-resistant grooves.

[0009] In a preferred embodiment, the shear-resistant groove and the shear-resistant column are cylindrical.

[0010] For ease of positioning, there are two sets of anti-shear grooves and anti-shear columns on one connecting surface, one on top of the other.

[0011] The strength of the anti-shear groove is preferably optimized, and the diameter of the anti-shear groove is between 1 / 3 and 1 / 2 of the thickness of the short template.

[0012] A preferred material for the inner ring mold frame is a 38CrMoAl alloy with a nitrided surface, wherein the long and short mold plates are made of nitrided 38CrMoAl alloy, while the outer frame is made of ordinary mold steel.

[0013] To increase the bonding strength of the template, the long template has low edges on both sides of the inner cavity surface, and the two ends of the short template rest on the low edges.

[0014] In a preferred embodiment, the groove structure is a cylindrical countersunk hole.

[0015] Alternatively, the groove structure is a conical hole.

[0016] To facilitate handling and securing, grooves are recessed on the outer surface of the outer frame.

[0017] In use, this utility model is installed on a magnetic powder forming machine, and magnetic powder is processed and formed inside the cavity. The upper and lower pressure heads will press the magnetic powder in the cavity into a magnet, and then the magnet is discharged from the discharge port at the bottom of the cavity under the action of the pressure head. The usage method is the same as that of the existing magnetic powder forming mold, and will not be described in detail here.

[0018] The beneficial effects of this utility model are as follows: 1. After nitriding, the warped edges of the slightly deformed template connection holes will embed into the groove structure, allowing the template and side plate to fit precisely. This method, which involves creating a groove structure on the softer, ordinary mold steel outer frame instead of directly trimming the nitrided 38CrMoAl alloy template, reduces the difficulty of mold making and ensures mold precision at a low cost. 2. The nitrided layer formed by the 38CrMoAl alloy on the mold surface has extremely high hardness and wear resistance. During the magnet forming process, friction and wear will occur between the mold and the magnet powder or blank. The wear-resistant nitrided layer can effectively reduce this wear and maintain the surface smoothness and dimensional accuracy of the mold. This not only improves the service life of the mold but also ensures the surface quality of the magnet products and reduces product defects caused by mold wear. 3. The inner frame can be replaced with different styles depending on the shape of the pressed magnet. After nitriding, the mold steel is difficult to process, but the magnet die-casting mold with this inner and outer frame structure design can be installed in the outer frame without fine-tuning the nitrided inner frame, ensuring its dimensional accuracy. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of Example 1.

[0020] Figure 2 This is an exploded schematic diagram of Example 1.

[0021] Figure 3 This is a schematic diagram of Example 2.

[0022] Figure 4 This is a schematic diagram of the warped state combined with the conical hole in Example 1.

[0023] Figure 5 This is a schematic diagram of the warping and cylindrical countersunk hole combination state in Example 2. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1 Combined with appendix Figure 1 Appendix Figure 2 Appendix Figure 4A magnetic powder forming mold includes an outer frame 1 and a mold frame 2 disposed within the outer frame 1; the outer frame 1 is formed by two long side plates 3 and two short side plates 4; the mold frame 2 is formed by four long templates 5 and short templates 6 made of tempered mold steel, with two long templates 5 and two short templates 6; the inner sides of the long templates 5 and short templates 6 are provided with cavities 7, the outer sides of the long templates 5 and short templates 6 are provided with template connection holes 8, and the surfaces of the long templates 5 and short templates 6 are provided with a nitriding layer 9; the long side plates 3 and short side plates 4 are provided with side plate connection holes 10, and the template connection holes 8 of the long templates 5 are connected to the long side plates 3. The two are fixed together by screws on the side plate connecting hole 10. The template connecting hole 8 of the short template 6 and the side plate connecting hole 10 of the short side plate 4 are fixed together by screws. The end of the long side plate 3 is provided with a clamping edge 11 protruding inward. The short side plate 4 is provided with steps 12 on both sides. When the long side plate 3 and the short side plate 4 are fixed together by threaded parts, the clamping edge 11 presses on the steps 12. The long side plate 3 and the short side plate 4 are provided with a groove structure 13 near the inner side of the side plate connecting hole 10. After nitriding treatment, the warping 14 at the thread of the template connecting hole 10 enters the groove structure 13 to achieve the cancellation.

[0026] To increase the connection strength between the short template 6 and the long template 5, an anti-shear groove 15 is provided on the connection surface between the short template 6 and the long template 5, and an anti-shear column 16 is provided in the anti-shear groove 15.

[0027] In a preferred embodiment, the anti-shear groove 15 and the anti-shear column 16 are cylindrical.

[0028] For ease of positioning, there are two sets of anti-shear grooves 15 and anti-shear columns 16 on one connecting surface, one on top of the other.

[0029] The strength of the anti-shear groove 15 is preferably optimized, wherein the diameter of the anti-shear groove 15 is 1 / 3 of the thickness of the short template 6.

[0030] A preferred material for the inner ring mold frame 2 is that the long template 5 and the short template 6 are made of 38CrMoAl alloy with surface nitriding treatment, while the outer frame 1 is made of ordinary mold steel.

[0031] In the appendix Figure 4 As shown, in a preferred embodiment, the groove structure 13 is a conical hole.

[0032] To facilitate handling and securing, a groove 17 is recessed on the outer side of the outer frame 1.

[0033] In this embodiment, the magnetic powder forming mold is installed on the magnetic powder forming machine, and the magnetic powder is processed and formed in the cavity 7. The upper and lower pressure heads will press the magnetic powder in the cavity 7 into a magnet, and then the magnet is discharged from the discharge port below the cavity 7 under the action of the pressure head. The usage method is the same as the magnetic powder forming mold of the prior art, and will not be described again here.

[0034] Example 2 Combined with appendix Figure 3 The same as the magnetic powder forming mold in Embodiment 1, the difference being that in order to increase the bonding strength of the template, the long template 5 has low edges 18 on both sides of the inner cavity 7, and the short template 6 rests on the low edges 18 at both ends.

[0035] In the appendix Figure 5 As shown, in another preferred embodiment, the groove structure 13 is a cylindrical countersunk hole. The warping 14 at the thread of the template connection hole 10 after nitriding treatment is offset by entering the cylindrical countersunk hole. Figure 5 The marking symbols are the same as those in Example 1.

[0036] In this embodiment, the magnetic powder forming mold is installed on the magnetic powder forming machine, and the magnetic powder is processed and formed in the cavity 7. The upper and lower pressure heads will press the magnetic powder in the cavity 7 into a magnet, and then the magnet is discharged from the discharge port below the cavity 7 under the action of the pressure head. The usage method is the same as the magnetic powder forming mold of the prior art, and will not be described again here.

[0037] The beneficial effects of this utility model are as follows: 1. After nitriding, the warped edges of the slightly deformed template connection holes will embed into the groove structure, allowing the template and side plate to fit precisely. This method, which involves creating a groove structure on the softer, ordinary mold steel outer frame instead of directly trimming the nitrided 38CrMoAl alloy template, reduces the difficulty of mold making and ensures mold precision at a low cost. 2. The nitrided layer formed by the 38CrMoAl alloy on the mold surface has extremely high hardness and wear resistance. During the magnet forming process, friction and wear will occur between the mold and the magnet powder or blank. The wear-resistant nitrided layer can effectively reduce this wear and maintain the surface smoothness and dimensional accuracy of the mold. This not only improves the service life of the mold but also ensures the surface quality of the magnet products and reduces product defects caused by mold wear. 3. The inner frame can be replaced with different styles depending on the shape of the pressed magnet. After nitriding, the mold steel is difficult to process, but the magnet die-casting mold with this inner and outer frame structure design can be installed in the outer frame without fine-tuning the nitrided inner frame, ensuring its dimensional accuracy.

Claims

1. A magnetic powder forming mold, characterized in that: The system includes an outer frame and a mold frame located within the outer frame. The outer frame is formed by two long side plates and two short side plates. The mold frame is formed by four long and short templates made of tempered mold steel, with two long templates and two short templates. The inner sides of the long and short templates are provided with cavities, and the outer sides of the long and short templates are provided with template connection holes. The surfaces of the long and short templates are provided with a nitriding layer. The long and short side plates are provided with side plate connection holes. The template connection holes of the long templates and the side plate connection holes of the long side plates are fixed together by screws. The template connection holes of the short templates and the side plate connection holes of the short side plates are fixed together by screws. The ends of the long side plates are provided with inwardly protruding clamping edges, and the sides of the short side plates are provided with steps. When the long and short side plates are fixed together by threaded parts, the clamping edges press against the steps. The long and short side plates are provided with recessed groove structures near the inner surfaces at the side plate connection holes.

2. The magnetic powder forming mold according to claim 1, characterized in that: The short template and the long template are provided with anti-shear grooves on the connecting surface, and anti-shear columns are provided in the anti-shear grooves.

3. The magnetic powder forming mold according to claim 2, characterized in that: The shear-resistant groove and shear-resistant column are cylindrical.

4. The magnetic powder forming mold according to claim 3, characterized in that: There are two sets of shear grooves and shear columns on a connecting surface, one on top of the other.

5. The magnetic powder forming mold according to claim 2, characterized in that: The diameter of the anti-shear groove is between 1 / 3 and 1 / 2 of the thickness of the short template.

6. The magnetic powder forming mold according to claim 1, characterized in that: The long and short templates are made of 38CrMoAl alloy with surface nitriding treatment.

7. The magnetic powder forming mold according to claim 1, characterized in that: The long template has low edges on both sides of the inner cavity surface, and the two ends of the short template rest on the low edges.

8. The magnetic powder forming mold according to claim 1, characterized in that: The groove structure is a cylindrical countersunk hole.

9. The magnetic powder forming mold according to claim 1, characterized in that: The groove structure is a conical hole.

10. The magnetic powder forming mold according to claim 1, characterized in that: The outer side of the outer frame is also recessed with a groove.

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