Sintering box for magnet

Abstract

The utility model discloses a sintering box for a magnet, and relates to the technical field of magnet sintering. The sintering box for the magnet comprises a plurality of box bodies which are arranged in an overlapped mode, the top face of the box body at the topmost portion is fully covered with a heat insulation plate, and the bottom face of the box body at the bottommost portion is fully covered with a heat insulation plate. The heat insulation plate can achieve the heat insulation effect, it is ensured that all the positions of the box body are heated as uniformly as possible, shrinkage of the sintered neodymium-iron-boron green body is consistent as much as possible, and the sintering quality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of magnet sintering, and particularly relates to a sintering box for magnets. Background Art

[0002] The sintering process is an important step in the production and manufacturing process of neodymium iron boron magnets. The sintering process mainly includes multiple stages such as a low-temperature pre-sintering stage, a medium-temperature heating and sintering stage, and a high-temperature heat preservation and completion of sintering stage. The effects produced in each stage are different.

[0003] The sintering box is mainly used to carry the green body of the neodymium iron boron magnet. During the sintering process, the green body needs to maintain the stability of its shape and structure in a high-temperature environment to avoid deformation or damage. The sintering box provides a stable support platform, enabling the green body to maintain its geometric shape at high temperature and ensuring the dimensional and shape accuracy of the final product. Currently, graphite material boxes are commonly used in the preparation process of sintered neodymium iron boron magnets. The graphite material box consists of a graphite box body and a graphite lid. The disadvantage of this graphite material box is that during the sintering process, due to more heat radiation received by the upper and lower layers of the material boxes, the temperature of the material boxes is higher, and the middle material box receives less heat radiation, so the temperature of the material box is lower. This temperature difference will cause inconsistent shrinkage of the sintered neodymium iron boron green body, and thus lead to dimensional differences in the sintered magnets.

[0004] Therefore, the prior art needs to be improved. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is that the upper and lower layers and the middle part of the graphite material box in the prior art are heated unevenly, resulting in dimensional differences in the sintered magnets. The purpose is to provide a sintering box for magnets, which adopts corresponding technical means and has the beneficial effects of ensuring uniform heating, reducing dimensional differences in sintering, and improving sintering quality.

[0006] The utility model is realized through the following technical solutions:

[0007] A sintering box for magnets, which includes a plurality of overlapping box bodies. The top surface of the topmost box body is completely covered with a heat insulation board, and the bottom surface of the bottommost box body is completely covered with a heat insulation board.

[0008] In the above technical solution, a heat insulation board is installed on the top surface of the topmost box body, and a heat insulation board is also installed on the bottom surface of the bottommost box body. The heat insulation board can play a heat insulation effect, reducing the heating of the top surface of the topmost box body and the bottom surface of the bottommost box body, ensuring that the heating of each part of the box body is as uniform as possible, and thus ensuring that the shrinkage of the sintered neodymium iron boron green body is as consistent as possible, and improving the sintering quality.

[0009] Furthermore, in the utility model, the above box body is provided with a heat storage structure.

[0010] Further, in the present utility model, the heat storage structure is configured as a block, and the heat storage structure is uniformly arranged on the bottom surface and the side surface of the box body.

[0011] Further, in the present utility model, a sandwich layer is arranged inside the box body, the heat storage structure is configured as a sheet, and the heat storage structure is arranged inside the sandwich layer.

[0012] Further, in the present utility model, the box body includes a bottom plate, and a side plate surrounding a circle is arranged on the edge of the bottom plate.

[0013] Further, in the present utility model, a limiting convex block for inserting into the side plate of the lower box body is arranged at the bottom of the bottom plate of the upper box body.

[0014] Further, in the present utility model, the limiting convex block has a conical surface.

[0015] Further, in the present utility model, the maximum side length of the limiting convex block is the same as the inner side length of the chamber surrounded by the side plate.

[0016] Further, in the present utility model, more than 3 box bodies are overlapped and arranged.

[0017] Further, in the present utility model, the heat insulation board is configured as a ceramic fiber aluminum silicate board with a thermal conductivity not higher than 0.2 W / m·K.

[0018] Compared with the prior art, the present utility model has the following advantages and beneficial effects:

[0019] The sintering box for magnets provided by the present utility model mainly consists of two parts: a box body and a heat insulation board. The box body is used to accommodate the neodymium iron boron magnet to be sintered. Two heat insulation boards are respectively covered on the top surface of the topmost box body and the bottom surface of the bottommost box body. The heat insulation board can play a heat insulation effect, reduce the heat received by the top surface of the topmost box body and the bottom surface of the bottommost box body, ensure that the heat received by each part of the box body is as uniform as possible and as consistent as possible, and further ensure that the shrinkage of the sintered neodymium iron boron green body is as consistent as possible, reduce the dimensional difference of sintering, and improve the sintering quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, form a part of this application, and do not constitute a limitation to the embodiments of the present utility model. In the drawings:

[0021] Figure 1 is a schematic structural diagram of the sintering box for magnets of the present utility model;

[0022] Figure 2 is a schematic cross-sectional view of the box body of the present utility model;

[0023] Figure 3 A schematic cross-sectional view of a side plate of the present utility model;

[0024] Figure 4 A schematic longitudinal sectional view of another side plate of the present utility model.

[0025] Reference numerals in the drawings and corresponding component names: 1 - box body, 101 - bottom plate, 102 - side plate, 103 - interlayer, 2 - heat insulation plate, 3 - heat storage structure, 301 - interlayer, 4 - bump, 401 - conical surface. Detailed implementation manners

[0026] To make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in combination with embodiments and the drawings. The illustrative embodiments and descriptions thereof of the present utility model are only used to explain the present utility model and do not limit the present utility model. The following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model to be protected, but only represents the selected 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 fall within the scope of protection of the present utility model.

[0027] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0028] In the description of the embodiments of the present utility model, it should also be noted that unless otherwise clearly specified and limited, if the terms "set", "installed", "connected", "connected" 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 components. 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.

[0029] Embodiment 1

[0030] Embodiment 1 of the present utility model provides a sintering box for magnets, as Figure 1 shown, and the specific structure is described as follows.

[0031] The sintering box for magnets in Embodiment 1 of the present utility model mainly consists of two parts: a box body 1 and a heat insulation plate 2. The box body 1 is used to contain and hold the magnet material to be sintered, such as the green body of a neodymium iron boron magnet, and the heat insulation plate 2 is used to block heat.

[0032] Further, in combination withFigure 1 As shown, the box body 1 of this embodiment is composed of a bottom plate 101 and four side plates 102, all made of graphite material. The bottom plate 101 is located at the bottom, and the four side plates 102 are sequentially connected end to end around the edge of the bottom plate 101. The side plates 102 and the bottom plate 101 enclose a cavity for accommodating the NdFeB magnet green body.

[0033] In some embodiments of this embodiment, the heat insulation plate 2 has a low heat conduction efficiency, so the heat insulation plate 2 can play a role in insulating heat. As Figure 1 shown, the sintering box for magnets of this embodiment includes 4 box bodies 1 neatly stacked from top to bottom (in other embodiments, 3 or 5 box bodies 1 can also be stacked). A heat insulation plate 2 is fixedly installed on the top surface of the topmost box body 1, and another heat insulation plate 2 is fixedly installed on the bottom surface of the bottommost box body 1. The size of the top heat insulation plate 2 is the same as the top surface of the box body 1, and the size of the bottom heat insulation plate 2 is the same as the bottom surface of the box body 1, ensuring that the heat insulation plate 2 can fully cover the top surface or the bottom surface of the box body 1 to achieve a better heat insulation effect.

[0034] Furthermore, the heat insulation plate 2 is made of a heat insulation material with a thermal conductivity not higher than 0.2 W / m·K, for example, a ceramic fiber aluminum silicate plate with a thermal conductivity of 0.2 W / m·K.

[0035] Using a ceramic fiber aluminum silicate plate with a thermal conductivity of 0.2 W / m·K as the heat insulation plate 2 for the sintering box for magnets with 5 overlapping box bodies 1, the following experimental data table is obtained after the green body is sintered. In the table, the control group is the experimental data of sintering the NdFeB magnet green body with a traditional graphite material box, and the experimental group is the experimental data of sintering the NdFeB magnet green body with the sintering box for magnets of this embodiment.

[0036]

[0037]

[0038] By comparing the standard deviation and range data in the table, for the sintering of the NdFeB magnet green body with five-layer box bodies 1, both the standard deviation and range of the five-layer box bodies 1 sintered in the experimental group are smaller than those of the five-layer graphite material box sintered in the control group. Whether it is the magnetization direction, the mold direction or the pressing direction, the standard deviation and range of the experimental group are lower. This shows that the sintering box for magnets in this embodiment 1 can ensure the consistent shrinkage of the sintered NdFeB green body, reduce the size difference of the sintered magnets, and improve the sintering quality.

[0039] Embodiment 2

[0040] The sintering box for magnets of this embodiment is based on the sintering box for magnets of Embodiment 1 and adds a limiting convex block 4.

[0041] Combined with Figure 2As shown in the figure, the limit bump 4 is fixedly installed on the bottom plate 101. Except for the bottommost box body 1 which does not have the limit bump 4 installed, the rest of the box bodies 1 are all installed with the limit bump 4. When overlapping and placing, the upper box body 1 is aligned with the lower box body 1, and the limit bump 4 at the bottom of the upper box body 1 is inserted into the top opening of the lower box body 1, so that the two box bodies 1 can be neatly overlapped easily, with a better installation effect.

[0042] Furthermore, in order to make the placement easier and more orderly, as Figure 2 shown, the limit bump 4 is in the form of a frustum of a square pyramid. The four sides of the frustum-of-a-square-pyramid limit bump 4 have conical surfaces 401. The size of the limit bump 4 gradually increases from bottom to top, making it easier to put the limit bump 4 into the top opening of the box body 1.

[0043] The maximum side length of the limit bump 4 is the same as the inner side length of the chamber formed by the side plate 102, that is, the top size of the limit bump 4 is the same as the top opening size of the box body 1, reducing the misalignment between two adjacent box bodies 1 and making the overlap more orderly.

[0044] Embodiment 3

[0045] The sintering box for magnets in this embodiment is based on the sintering box for magnets in Embodiment 1, and is additionally provided with a heat storage structure 3 to prevent the temperature inside the box body 1 from changing rapidly with the temperature outside the box body 1, which affects the sintering quality.

[0046] Combined with Figure 3 shown, the heat storage structure 3 can adopt massive corundum mullite, which has the advantages of heat storage, heat resistance and low shrinkage. The massive heat storage structure 3 is fixedly installed on the bottom surface and side surface of the box body 1, that is, the bottom plate 101 and the side plate 102, to play a role in heat storage and ensure the sintering quality.

[0047] Combined with Figure 4 shown, the heat storage structure 3 can also adopt a sheet-shaped ceramic body. An interlayer 103 is provided on the side surface of the box body 1, and the sheet-shaped heat storage structure 3 is installed inside the interlayer 103 to play a role in heat storage and ensure the sintering quality.

[0048] In summary, the utility model provides a sintering box for magnets, which includes a plurality of overlapping box bodies 1, the top surface of the top box body 1 is fully covered with a heat insulation board 2, and the bottom surface of the bottom box body 1 is fully covered with a heat insulation board 2. The box body 1 is provided with a heat storage structure 3. The heat storage structure 3 is configured in a block shape, and the heat storage structure 3 is evenly arranged on the bottom surface and side of the box body 1. An interlayer 103 is arranged inside the box body 1, and the heat storage structure 3 is configured in a sheet shape, and the heat storage structure 3 is arranged in the interlayer 301. The box body 1 includes a bottom plate 101, and the edge of the bottom plate 101 is provided with a side plate 102 that is surrounded in a circle. A limiting protrusion 4 is provided at the bottom of the bottom plate 101 of the upper box body 1, which is inserted into the side plate 102 of the lower box body 1. The limiting protrusion 4 has a conical surface 401. The maximum side length of the limiting protrusion 4 is the same as the side length of the inner side of the chamber surrounded by the side plate 102. More than three box bodies 1 are overlapped. The heat insulation board 2 is configured as a ceramic fiber aluminum silicate board with a thermal conductivity of no more than 0.2 W / m·K. Therefore, the magnet sintering box of the utility model has the beneficial effects of ensuring uniform heating, reducing sintering size differences, and improving sintering quality.

[0049] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A sintering box for magnet, characterized in that: It comprises a plurality of overlapping box bodies (1), wherein the top surface of the topmost box body (1) is completely covered with a heat insulation board (2), and the bottom surface of the bottommost box body (1) is completely covered with a heat insulation board (2).

2. The sintering box for magnet according to claim 1, characterized in that: The box body (1) is provided with a heat storage structure (3).

3. The sintering box for magnet according to claim 2, characterized in that: The heat storage structure (3) is configured in a block shape, and the heat storage structure (3) is evenly arranged on the bottom surface and side surfaces of the box body (1).

4. The sintering box for magnet according to claim 2, characterized in that: An interlayer (103) is provided inside the box body (1); the heat storage structure (3) is configured in a sheet shape; and the heat storage structure (3) is arranged inside the interlayer (103).

5. The sintering box for magnet according to claim 1, characterized in that: The box body (1) comprises a bottom plate (101), and the edge of the bottom plate (101) is provided with side plates (102) forming a circle.

6. The sintering box for magnet according to claim 5, characterized in that: A limiting protrusion (4) is provided at the bottom of the bottom plate (101) of the upper box body (1) and is inserted into the side plate (102) of the lower box body (1).

7. The sintering box for magnet according to claim 6, characterized in that: The limiting protrusion (4) has a conical surface (401).

8. The sintering box for magnet according to claim 7, characterized in that: The maximum side length of the limiting protrusion (4) is the same as the inner side length of the chamber surrounded by the side plate (102).

9. The sintering box for magnet according to claim 1, characterized in that: More than three box bodies (1) are arranged in an overlapping manner.

10. The sintering box for magnet according to claim 1, characterized in that: The heat insulation board (2) is configured as a ceramic fiber aluminum silicate board with a thermal conductivity coefficient not higher than 0.2 W / m·K.

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