Die for improving deformation of neodymium-iron-boron magnet
Through the mold design of the inner concave indentation head and cemented carbide layer, the problem of surface depressed deformation in the production of NdFeB magnets is solved, which improves product qualification rate and reduces production costs.
Patent Information
- Application Number
- CN202421751288.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-23
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-07-23
AI Technical Summary
In the production of traditional neodymium iron boron magnets, bidirectional molding of magnetic field molding presses leads to depressed and deformation of the product surface, reducing the pass rate and increasing production costs.
The mold design of the inner concave indentation head and cemented carbide layer is adopted, combining the low-roughness inner wall and appropriate demolding slope to reduce magnetic powder running and surface depression and improve density uniformity.
Effectively reduce the depressed deformation of magnet surface, improve product qualification rate, and reduce production costs.
Smart Images
Figure CN223123732U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of molds, in particular to a mold for improving the deformation of neodymium iron boron magnets. Background Art
[0002] The traditional production process of neodymium iron boron magnets includes smelting process, forming process, sintering process, etc. The forming process includes: putting neodymium iron boron powder into a mold, and then pressing it into a neodymium iron boron magnet block.
[0003] Due to the reason of double-sided forming of the magnetic field forming press, the neodymium iron boron magnet is prone to concave deformation on the pressed surface of the product after sintering, resulting in a low qualified rate of the product, directly affecting the material yield of the subsequent process, and increasing the production cost. Summary of the Invention
[0004] Aiming at the above problems existing in the production of existing neodymium iron boron magnets, the present invention aims to provide a mold for improving the deformation of neodymium iron boron magnets with high qualified rate, low cost and easy demolding.
[0005] The specific technical solutions are as follows:
[0006] A mold for improving the deformation of neodymium iron boron magnets, comprising: a mold body and an upper pressure head. The mold body has a receiving cavity for receiving magnetic powder to be pressed into shape. The bottom of the upper pressure head has a pressing surface, which matches the cross-section of the receiving cavity, and the upper pressure head can be operably moved towards the receiving cavity so that the pressing surface extrudes the magnetic powder in the receiving cavity to form a neodymium iron boron magnet block;
[0007] Wherein, the pressing surface is a concave surface.
[0008] As a further improvement and optimization of this solution, the mold body includes: two magnetic conductive plates and two side plates. The two side plates are connected between the two magnetic conductive plates and enclose the receiving cavity together.
[0009] As a further improvement and optimization of this solution, the opposite end faces of the two magnetic conductive plates both have cemented carbide layers.
[0010] As a further improvement and optimization of this solution, the thickness of the cemented carbide layer is 2-5 mm.
[0011] As a further improvement and optimization of this solution, each side plate is detachably connected to the two magnetic conductive plates through a connecting piece.
[0012] As a further improvement and optimization of this solution, each magnetic conductive plate is surrounded by an insert block on the outside.
[0013] The roughness of the inner wall of the receiving cavity is less than or equal to 0.2 μm.
[0014] As a further improvement and optimization of this solution, the demoulding slope of the improved NdFeB magnet deformation die is 1-3°.
[0015] As a further improvement and optimization of this solution, the demoulding height of the improved NdFeB magnet deformation die is 2.0-2.3 times the pressing size.
[0016] The positive effects of the above technical solution compared with the prior art are as follows:
[0017] (1) In the present utility model, the extrusion surface of the upper punch is concave. The use of the concave compensation method is beneficial to reducing the generation of depression deformation on the pressing surface of the magnet, reducing the movement of magnetic powder during the magnetization process, making the density of the magnet more uniform, and improving the product qualification rate.
[0018] (2) In the present utility model, both opposite end faces of the two magnetic conduction plates are provided with cemented carbide layers, which are beneficial to pressing the magnetic powder into shape and reducing the generation of surface depression of the magnet after sintering. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a cross-sectional schematic view of an improved NdFeB magnet deformation die of the present utility model;
[0020] Figure 2 It is a structural schematic view of the upper punch of an improved NdFeB magnet deformation die of the present utility model;
[0021] In the drawings: 1. Die body; 2. Upper punch; 11. Magnetic conduction plate; 12. Side plate; 13. Insert block; 14. Cemented carbide layer; 15. Connecting piece; 16. Accommodating cavity; 21. Pressing surface. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] The technical solution of the present utility model will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0023] In the description of the present utility model, it should be noted that when terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, when terms such as "first", "second", "third" appear, they are only for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0024] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, when terms such as "installation", "connection", "coupling" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0025] Figure 1 It is a cross-sectional schematic diagram of a die for improving the deformation of neodymium iron boron magnets according to the present utility model. Figure 2 It is a structural schematic diagram of the upper punch of a die for improving the deformation of neodymium iron boron magnets according to the present utility model. As Figure 1-2 shown, a die for improving the deformation of neodymium iron boron magnets in a preferred embodiment is shown, including: a die body 1 and an upper punch 2. The die body 1 has a receiving cavity 16 for receiving the magnetic powder to be pressed into shape. The bottom of the upper punch 2 has a pressing surface 21, and the pressing surface 21 matches the cross-section of the receiving cavity 16. And the upper punch 2 can be operably moved towards the inside of the receiving cavity 16 so that the pressing surface 21 squeezes the magnetic powder in the receiving cavity 16 to form a neodymium iron boron magnet block. Among them, the pressing surface 21 is a concave surface.
[0026] Specifically, the upper punch 2 is connected to a magnetic field forming press and is driven by the magnetic field forming press to move towards the inside of the receiving cavity 16 to squeeze the magnetic powder in the receiving cavity 16 to form a neodymium iron boron magnet block.
[0027] In this embodiment, the extrusion surface 21 of the upper punch 2 is a concave surface. Adopting the concave compensation method is beneficial to reducing the generation of depression deformation on the pressing surface of the magnet, reducing the movement of the magnetic powder during the magnetization process, making the density of the magnet more uniform, and improving the product qualification rate.
[0028] As a further improvement and optimization of this solution, the die body 1 includes: two magnetic conductive plates 11 and two side plates 12. The two side plates 12 are connected between the two magnetic conductive plates 11 and enclose the receiving cavity 16 together.
[0029] As a further improvement and optimization of this solution, the opposite end faces of the two magnetic conduction plates 11 both have cemented carbide layers 14, which are conducive to pressing the magnetic powder into shape and reducing the generation of surface depressions on the magnet after sintering.
[0030] As a further improvement and optimization of this solution, the thickness of the cemented carbide layer 14 is 2 - 5 mm.
[0031] In the embodiment, the cemented carbide layer 14 can be a non-magnetic material, such as a non-magnetic G60 steel layer, and the thickness of the cemented carbide layer 14 is preferably 3 - 5 mm.
[0032] As a further improvement and optimization of this solution, each side plate 12 is detachably connected to the two magnetic conduction plates 11 through a connecting member 15. More preferably, the connecting member 15 can be a bolt.
[0033] Specifically, the two magnetic conduction plates 11 are each provided with two grooves on both sides of the opposite end faces. One groove is configured to accommodate one end of a side plate 12, and the other groove is configured to accommodate one end of the other side plate 12; the two grooves are arranged relatively parallel, so that the structure of the formed mold is more stable, which is conducive to obtaining a qualified pressed magnet.
[0034] More preferably, a counterbore is provided at the corner of one magnetic conduction plate 11; a threaded hole is provided at the corner of the other magnetic conduction plate 11; the connecting member 15 is configured to fixedly connect the two magnetic conduction plates 11 through the counterbore and the threaded hole, which is conducive to forming a mold with a stable structure.
[0035] As a further improvement and optimization of this solution, each magnetic conduction plate 11 is surrounded by an insert 13. The material of the magnetic conduction plate 11 can be magnetic conduction Cr12. The shape of the magnetic conduction plate 11 of the present utility model is approximately close to a cuboid. The material of the insert 13 can be non-magnetic G60; the material of the side plate 12 can be 304 stainless steel.
[0036] The roughness of the inner wall of the accommodating cavity 16 is less than or equal to 0.2 μm. The surface roughness refers to the unevenness of the processed surface with smaller spacing and minute peaks and valleys. This is conducive to reducing the friction between the inner surface of the accommodating cavity 16 of the pressed mold and the magnet powder to be pressed into shape, which is conducive to smooth demolding.
[0037] As a further improvement and optimization of this solution, the demolding slope of the improved NdFeB magnet deformation mold is 1 - 3°.
[0038] As a further improvement and optimization of this solution, the demolding height of the improved NdFeB magnet deformation mold is 2.0 - 2.3 times the pressing size.
[0039] Specifically, in this embodiment, the non-oriented direction of the die for improving the deformation of the NdFeB magnet is 75 mm, the pressing direction is 45 mm, the orientation direction is 52 mm, the density of the magnet formed by pressing can reach 4.0 - 4.2 g / cm3, the demoulding height of the die is 94.5 mm. In some embodiments, the cross-section of the accommodating cavity 16 is rectangular, as Figure 1 shown, the non-oriented direction is Figure 1 the length direction of the cross-section of the accommodating cavity 16 in Figure 1 the width direction of the cross-section of the accommodating cavity 16 in Figure 1 the direction perpendicular to the cross-section of the accommodating cavity 16 in
[0040] The above are only the preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that all the equivalent replacements and obvious changes made by using the description and illustrations of the present invention should be included in the protection scope of the present invention.
Claims
1. An improved die for NdFeB magnets, characterized in that, Comprising: A mold body and an upper punch. The mold body has a receiving cavity for receiving magnetic powder to be pressed into shape. The bottom of the upper punch has a pressing surface, which matches the cross-section of the receiving cavity, and the upper punch is operably movable towards the inside of the receiving cavity so that the pressing surface squeezes the magnetic powder in the receiving cavity to form a neodymium iron boron magnet block; Wherein, the pressing surface is a concave surface.
2. The improved NdFeB magnet deformation die according to claim 1, wherein The mold body includes: two magnetic conductive plates and two side plates. The two side plates are connected between the two magnetic conductive plates and enclose the receiving cavity together.
3. The improved deformation die for NdFeB magnets according to claim 2, characterized in that, The opposite end faces of the two magnetic conductive plates both have cemented carbide layers.
4. The improved NdFeB magnet deformation die according to claim 3, characterized in that The thickness of the cemented carbide layer is 2 - 5 mm.
5. The improved NdFeB magnet deformation die according to any one of claims 2-4, characterized in that Each side plate is detachably connected to the two magnetic conductive plates through a connecting member.
6. The improved deformation die for NdFeB magnets according to any one of claims 2-4, characterized in that, Each magnetic conductive plate is surrounded by an insert block on the outside.
7. The improved NdFeB magnet deformation die according to any one of claims 1-4, characterized in that, The roughness of the inner wall of the receiving cavity is less than or equal to 0.2 μm.
8. The improved NdFeB magnet deformation die according to any one of claims 1-4, characterized in that The demolding slope of the improved neodymium iron boron magnet deformation mold is 1 - 3°.
9. The improved NdFeB magnet deformation die according to any one of claims 1-4, characterized in that, The demolding height of the improved neodymium iron boron magnet deformation mold is 2.0 - 2.3 times the pressing size.