Jig for inhibiting sintering deformation of magnetic material injection molded part
By designing a ring-shaped fixture body, stable positioning and stress dispersion of magnetic material injection molded parts are achieved, solving the sintering deformation problem, improving product quality and production efficiency, and making it suitable for the manufacturing of precision electronic components and complex structures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HENGDIAN GRP DMEGC MAGNETICS CO LTD
- Filing Date
- 2025-09-22
- Publication Date
- 2026-07-31
AI Technical Summary
Soft magnetic ferrite injection molded parts are prone to deformation during sintering. Traditional tooling cannot effectively counteract gravity and thermal stress, resulting in low product qualification rate and difficulty in meeting the dimensional accuracy requirements of precision electronic devices.
Design a jig body with a ring structure, having an outer ring wall, an inner ring wall, and first and second ring end faces. The jig body is made of the same material as the magnetic injection molded part. The gap between the outer ring wall and the inner ring is designed to provide stable support for the suspended part and match thermal expansion, thereby reducing deformation.
It effectively suppresses sintering deformation of magnetic material injection molded parts, improves product dimensional accuracy and production qualification rate, and enhances production efficiency. It is suitable for the manufacture of precision electronic components and complex structures.
Smart Images
Figure CN224582127U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of magnetic material sintering technology, and in particular to a jig for suppressing sintering deformation of magnetic material injection molded parts. Background Technology
[0002] Soft magnetic ferrite materials, with their excellent magnetic properties such as high permeability and low coercivity, are widely used in electronics, communications, and other fields. Their injection molding process enables the efficient production of complex-shaped products, but the sintering process is a crucial step determining product quality. In actual production, soft magnetic ferrite injection-molded parts face many challenges during sintering: on the one hand, the material undergoes physicochemical changes during high-temperature sintering, leading to a redistribution of internal stress and making it highly susceptible to deformation; on the other hand, traditional sintering methods often employ simple load-bearing fixtures, which cannot provide targeted support and positioning for the molded parts, making it difficult to counteract deformation caused by gravity and thermal stress, resulting in low product yield and dimensional accuracy that fails to meet the assembly requirements of precision electronic devices.
[0003] Therefore, there is an urgent need for a fixture to suppress the sintering deformation of injection molded magnetic materials in order to solve the above problems. Utility Model Content
[0004] The purpose of this utility model is to provide a fixture for suppressing the sintering deformation of magnetic material injection molded parts, so as to avoid the deformation of magnetic material injection molded parts during the sintering process and improve product quality and production efficiency.
[0005] Based on the above concept, the technical solution adopted by this utility model is as follows:
[0006] A fixture for suppressing sintering deformation of magnetic material injection molded parts is provided, applicable to magnetic material injection molded parts with a suspended part in the inner ring. The fixture for suppressing sintering deformation of magnetic material injection molded parts includes a fixture body, the fixture body is a ring structure, the ring structure has an annular outer wall surface, an annular inner wall surface, a first annular end surface and a second annular end surface, the first annular end surface and the second annular end surface are arranged opposite to each other along the axial direction of the ring structure;
[0007] The fixture body is located in the inner ring of the magnetic material injection molded part, and the first annular end face or the second annular end face abuts against the suspended part in the axial direction of the annular structure and extends out of the suspended part in the radial direction of the annular structure.
[0008] The annular outer wall surface has a gap with the inner ring of the magnetic material injection molded part, and the radial gap between the annular outer wall surface and the magnetic material injection molded part in the annular structure is d1, where d1 = 1 ± 0.03 mm.
[0009] The fixture body is made of the same material as the magnetic material injection molded part.
[0010] Optionally, the first end of the annular outer wall surface connected to the first annular end face is provided with a first chamfer of R1, 0.1mm≤R1≤0.2mm, and the first annular inclined surface of the first end with a width of L1 in the axial direction of the annular structure forms a first angle a1 with the axial direction of the annular structure, 2°≤a1≤4°, 0.4mm≤L1≤0.6mm.
[0011] Optionally, the roughness of the first annular end face is Ra1, where Ra1 ≤ 0.8 μm.
[0012] Optionally, the second end of the annular outer wall surface connected to the second annular end face is provided with a second chamfer of R2, 0.1mm≤R2≤0.2mm, and the second end of the second annular surface with a width of L2 in the axial direction of the annular structure forms a second included angle a2 with the axial direction of the annular structure, 2°≤a2≤4°, 0.4mm≤L2≤0.6mm.
[0013] Optionally, the roughness of the second annular end face is Ra2, where Ra2 ≤ 0.8 μm.
[0014] Optionally, the magnetic material injection molded part is coaxially arranged with the fixture body, and the radial distance between the annular inner wall surface and the suspended part in the annular structure is d2, where 3mm≤d2≤5mm.
[0015] Optionally, both the fixture body and the magnetic material injection molded part are made of Mn-Zn ferrite composite material.
[0016] Optionally, the fixture body is manufactured using an injection molding process.
[0017] Optionally, the density of the fixture body is ρ1, 3.31 g / cm³. 3 ≤ρ1≤3.32g / cm 3 ;
[0018] The density of the magnetic material injection molded part is ρ2, 3.31 g / cm³. 3 ≤ρ2≤3.32g / cm 3 .
[0019] Optionally, the shrinkage rate of the fixture body is 1.19;
[0020] The shrinkage rate of the magnetic material injection molded part is 1.19.
[0021] The beneficial effects of this utility model are as follows:
[0022] This invention proposes a fixture for suppressing sintering deformation of magnetic material injection molded parts. It is applicable to magnetic material injection molded parts with a suspended portion. The fixture includes a fixture body, which is a ring structure. This ring structure has an outer ring wall, an inner ring wall, a first ring end face, and a second ring end face. The first and second ring end faces are arranged opposite each other along the axial direction of the ring structure. When the fixture body is placed in the inner ring of the magnetic material injection molded part and below the suspended portion, the first or second ring end face abuts against the suspended portion along the axial direction of the fixture body. To ensure effective support of the suspended portion by the fixture body, the first or second ring end face abuts against the suspended portion radially beyond the suspended portion of the ring structure. The entire ring of the fixture body provides support, and the height of the fixture body is designed to match the cavity depth of the magnetic material injection molded part to distribute gravity and thermal stress and prevent localized deformation. Furthermore, when the jig body is located within the inner ring of the magnetic material injection molded part, there is a gap between the annular outer wall surface and the inner ring of the magnetic material injection molded part. The radial gap between the annular outer wall surface and the magnetic material injection molded part in the annular structure is d1, where d1 = 1 ± 0.03 mm. This reduces the shaking and displacement of the magnetic material injection molded part during sintering and prevents the jig body and the magnetic material injection molded part from jamming due to thermal expansion during sintering. Secondly, since the jig body and the magnetic material injection molded part are made of the same material, their coefficients of thermal expansion are the same. This allows the jig body and the magnetic material injection molded part to contract and expand synchronously during the heating and cooling stages of sintering, reducing deformation caused by differences in thermal stress. This jig, used to suppress sintering deformation of magnetic material injection molded parts, achieves stable positioning, uniform support, and stress dispersion of the magnetic material injection molded parts during sintering, effectively reducing sintering deformation, improving product dimensional accuracy and molding quality, and increasing production pass rate and efficiency. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of a jig body and a magnetic material injection molded part provided in an embodiment of this utility model;
[0024] Figure 2 This is a cross-sectional view of a jig body and a magnetic material injection molded part provided in an embodiment of this utility model;
[0025] Figure 3 This is a first-view structural schematic diagram of a fixture body provided in an embodiment of the present utility model;
[0026] Figure 4 This is a structural schematic diagram of a jig body from a second perspective, provided in an embodiment of the present invention;
[0027] Figure 5 yes Figure 4 Enlarged view of point A in the middle;
[0028] Figure 6 This is a second-view structural schematic diagram of another fixture body provided in an embodiment of the present invention;
[0029] Figure 7 yes Figure 6 Enlarged view of point B in the middle;
[0030] Figure 8 This is a third-view structural schematic diagram of a fixture body provided in an embodiment of the present invention;
[0031] Figure 9 yes Figure 8 Enlarged view of point C in the middle.
[0032] In the picture:
[0033] 1. Fixture body; 11. First annular end face; 12. Second annular end face; 13. Outer annular wall surface; 131. First chamfer; 132. First annular inclined surface; 133. Second chamfer; 134. Second annular inclined surface; 14. Inner annular wall surface;
[0034] 2. Magnetic material injection molded parts; 21. Suspended parts. Detailed Implementation
[0035] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the accompanying drawings, not all of them.
[0036] In the description of this utility model, 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 utility model based on the specific circumstances.
[0037] 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.
[0038] In the description of this embodiment, the terms "upper," "lower," "left," and "right," 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 utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0039] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0040] like Figures 1 to 9 As shown, this embodiment provides a fixture for suppressing sintering deformation of magnetic material injection molded parts. It is applicable to magnetic material injection molded parts 2 with a suspended portion 21. The fixture for suppressing sintering deformation of magnetic material injection molded parts includes a fixture body 1, which has a ring structure. The fixture body 1 is placed in the inner ring of the magnetic material injection molded part 2 and is located below the suspended portion 21, so as to provide axial and radial support for the suspended portion 21 in the fixture body 1. This can prevent the magnetic material injection molded part 2 from deforming during the sintering process, thereby improving product quality and production efficiency.
[0041] Specifically, the annular structure has an outer annular wall surface 13, an inner annular wall surface 14, a first annular end face 11, and a second annular end face 12. The first annular end face 11 and the second annular end face 12 are arranged opposite each other along the axial direction of the annular structure. When the fixture body 1 is placed in the inner ring of the magnetic material injection molded part 2 and is below the suspended part 21, the first annular end face 11 or the second annular end face 12 abuts against the suspended part 21 in the axial direction of the fixture body 1. To ensure effective support of the suspended part 21 by the fixture body 1, the first annular end face 11 or the second annular end face 12 that abuts against the suspended part 21 extends radially beyond the suspended part 21 of the annular structure. The entire ring of the fixture body 1 provides support, and the height of the fixture body 1 is designed to be consistent with the cavity depth of the magnetic material injection molded part 2 to distribute gravity and thermal stress and prevent local deformation. Furthermore, when the fixture body 1 is located within the inner ring of the magnetic material injection molded part 2, there is a gap between the annular outer wall surface 13 and the inner ring of the magnetic material injection molded part 2. The radial gap between the annular outer wall surface 13 and the magnetic material injection molded part 2 in the annular structure is d1, where d1 = 1 ± 0.03 mm. This reduces the shaking and displacement of the magnetic material injection molded part 2 during sintering and prevents the fixture body 1 and the magnetic material injection molded part 2 from jamming due to thermal expansion during sintering. Secondly, since the fixture body 1 and the magnetic material injection molded part 2 are made of the same material, their coefficients of thermal expansion are the same. Therefore, during the heating and cooling stages of sintering, the fixture body 1 and the magnetic material injection molded part 2 can contract and expand synchronously, reducing deformation caused by differences in thermal stress. This fixture, used to suppress sintering deformation of the magnetic material injection molded part, can achieve stable positioning, uniform support, and stress dispersion of the magnetic material injection molded part 2 during sintering, effectively reducing sintering deformation, improving product dimensional accuracy and molding quality, and increasing production qualification rate and efficiency.
[0042] like Figure 4 As shown, in this embodiment, the fixture body 1 is placed on the inner ring of the magnetic material injection molded part 2, and the first annular end face 11 abuts against the suspended part 21 in the axial direction of the annular structure.
[0043] Optionally, the first end of the annular outer wall surface 13 connected to the first annular end face 11 is provided with a first chamfer 131 of R1, 0.1mm≤R1≤0.2mm, and the first annular inclined surface 132 with a width of L1 in the axial direction of the first end of the annular structure forms a first angle a1 with the axial direction of the annular structure, 2°≤a1≤4°, 0.4mm≤L1≤0.6mm, which can facilitate quick alignment between the fixture body 1 and the inner ring of the magnetic material injection molded part 2, and reduce installation wear.
[0044] like Figure 5As shown, in this embodiment, the first end of the annular outer wall surface 13 connected to the first annular end surface 11 is provided with a first chamfer 131 of R1, R1 = 0.15mm, and the first annular inclined surface 132 with a width of L1 in the axial direction of the first end of the annular structure forms a first angle a1 with the axial direction of the annular structure, a1 = 3°, L1 = 0.5mm.
[0045] Optionally, the roughness of the first annular end face 11 is Ra1, Ra1≤0.8μm, and the friction between the first annular end face 11 and the suspended part 21 is small, so as to ensure that when the gap between the annular outer wall surface 13 and the magnetic material injection molded part 2 is small, the fixture body 1 can still be easily embedded into its inner ring.
[0046] like Figure 6 As shown, in this embodiment, the fixture body 1 is placed in the inner ring of the magnetic material injection molded part 2, and either the first annular end face 11 or the second annular end face 12 can abut against the suspended part 21 in the axial direction of the annular structure. That is, when the fixture body 1 is placed in the inner ring of the magnetic material injection molded part 2, there is no need to distinguish between the first annular end face 11 and the second annular end face 12, which can further improve work efficiency.
[0047] Optionally, the second end of the annular outer wall surface 13 connecting to the second annular end face 12 is provided with a second chamfer 133 of R2, 0.1mm≤R2≤0.2mm, and the second annular inclined surface 134 with a width of L2 in the axial direction of the second end of the annular structure forms a second angle a2 with the axial direction of the annular structure, 2°≤a2≤4°, 0.4mm≤L2≤0.6mm, which can facilitate quick alignment between the fixture body 1 and the inner ring of the magnetic material injection molded part 2, and reduce installation wear.
[0048] like Figure 7 As shown, in this embodiment, the second end of the annular outer wall surface 13 connected to the second annular end surface 12 is provided with a second chamfer 133 of R2, R2 = 0.15mm, and the second annular inclined surface 134 with a width of L2 in the axial direction of the second end of the annular structure forms a second angle a2 with the axial direction of the annular structure, a2 = 3°, L2 = 0.5mm.
[0049] Optionally, the roughness of the second annular end face 12 is Ra2, Ra2≤0.8μm, and the friction between the second annular end face 12 and the suspended part 21 is small, so as to ensure that when the gap between the annular outer wall surface 13 and the magnetic material injection molded part 2 is small, the fixture body 1 can still be easily embedded into its inner ring.
[0050] Optionally, the magnetic material injection molded part 2 is coaxially arranged with the fixture body 1, and the radial distance between the annular inner wall surface 14 and the suspended part 21 in the annular structure is d2, where 3mm≤d2≤5mm. The inner ring diameter of the annular structure is smaller than the size of the suspended part 21 to ensure support for the suspended part 21.
[0051] In this embodiment, both the fixture body 1 and the magnetic material injection molded part 2 are made of Mn-Zn ferrite composite material.
[0052] In this embodiment, the fixture body 1 is also made using injection molding.
[0053] In this embodiment, the density of the jig body 1 is ρ1, 3.31 g / cm³. 3 ≤ρ1≤3.32g / cm 3 The density of the magnetic material injection molded part 2 is ρ², 3.31 g / cm³. 3 ≤ρ2≤3.32g / cm 3 .
[0054] In this embodiment, the shrinkage rate of the fixture body 1 is 1.19. The shrinkage rate of the magnetic material injection molded part 2 is 1.19.
[0055] In practice, the contact surfaces of the fixture body 1 and the magnetic material injection molded part 2 should first be ultrasonically cleaned with anhydrous ethanol for 10 minutes to remove oil and metal debris, thus preventing impurities from affecting the uniformity of shrinkage. After placing the fixture body 1 on the inner ring of the magnetic material injection molded part 2, a feeler gauge should be used to check the circumferential gap between the annular outer wall surface 13 and the inner ring of the product. The measurement should be taken every 60°, and the deviation should be less than or equal to 0.03mm. If the deviation exceeds the tolerance, the surface of the fixture body 1 should be ground or the product clamping position should be adjusted. The assembled assembly was placed in an oxalic acid degreasing furnace and degreased at 130°C with an acid feed rate of 2 g / min. The degreased magnetic material injection molded part 2 of the assembly was sintered at 1310°C for 7 hours under N2 control with an oxygen content of 21 vol%. Then, it was sintered at 1310°C for 2 hours under N2 control with an oxygen content of 2 vol%. The cooling stage was carried out under balanced oxygen partial pressure. After sintering, a mechanically assisted separation method was used, in which rubber hammers or wooden mallets were used to gently tap the non-load-bearing parts of the fixture to gradually loosen and separate the parts.
[0056] This fixture, used to suppress sintering deformation of magnetic material injection molded parts, features a multi-layered design combining structural support, thermal matching, and process synergy. It fundamentally solves the deformation problem of the suspended portion 21 in the magnetic material injection molded part 2, making it particularly suitable for fields with high dimensional accuracy requirements, such as precision electronic components, automotive parts, and medical devices. Its core advantage lies not only in improving product yield but also in providing feasible manufacturing solutions for complex structural designs and new material applications, driving the development of injection molding processes towards higher precision and intelligence.
[0057] The above embodiments merely illustrate the basic principles and characteristics of this utility model. This utility model is not limited to the above embodiments. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A jig for inhibiting sintering distortion of a magnetic material injection molded piece, which is suitable for a magnetic material injection molded piece (2) having a suspended portion (21) in an inner ring, characterized in that, The fixture for suppressing sintering deformation of magnetic material injection molded parts includes a fixture body (1), the fixture body (1) is a ring structure, the ring structure has an annular outer wall surface (13), an annular inner wall surface (14), a first annular end surface (11) and a second annular end surface (12), the first annular end surface (11) and the second annular end surface (12) are arranged opposite to each other along the axial direction of the ring structure; The fixture body (1) is located in the inner ring of the magnetic material injection molded part (2), and the first annular end face (11) or the second annular end face (12) abuts against the suspended part (21) in the axial direction of the annular structure and extends out of the suspended part (21) in the radial direction of the annular structure. The annular outer wall surface (13) has a gap with the inner ring of the magnetic material injection molded part (2), and the radial gap between the annular outer wall surface (13) and the magnetic material injection molded part (2) in the annular structure is d1, where d1 = 1 ± 0.03 mm. The fixture body (1) is made of the same material as the magnetic material injection molded part (2).
2. The fixture for suppressing sintering deformation of injection-molded magnetic material parts according to claim 1, characterized in that, The first end of the annular outer wall surface (13) connected to the first annular end surface (11) is provided with a first chamfer (131) of R1, 0.1mm≤R1≤0.2mm, and the first end of the first annular inclined surface (132) with a width of L1 in the axial direction of the annular structure forms a first angle a1 with the axial direction of the annular structure, 2°≤a1≤4°, 0.4mm≤L1≤0.6mm.
3. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to any one of claims 1 or 2, characterized by, The roughness of the first annular end face (11) is Ra1, Ra1≤0.8μm.
4. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 2, wherein The second end of the annular outer wall surface (13) connected to the second annular end surface (12) is provided with a second chamfer (133) of R2, 0.1mm≤R2≤0.2mm, and the second end of the second annular surface with a width of L2 in the axial direction of the annular structure forms a second included angle a2 with the axial direction of the annular structure, 2°≤a2≤4°, 0.4mm≤L2≤0.6mm.
5. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to any one of claims 1 or 4, characterized by, The roughness of the second annular end face (12) is Ra2, Ra2≤0.8μm.
6. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 1, wherein The magnetic material injection molded part (2) is coaxially arranged with the fixture body (1), and the radial distance between the annular inner wall surface (14) and the suspended part (21) in the annular structure is d2, 3mm≤d2≤5mm.
7. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 1, wherein Both the fixture body (1) and the magnetic material injection molded part (2) are made of Mn-Zn ferrite composite material.
8. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 7, wherein The fixture body (1) is made by injection molding.
9. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 7, wherein The density of the jig body (1) is pi, 3.31 g / cm 3 ≤ pi ≤ 3.32 g / cm 3 ; The density of the magnetic material injection-molded piece (2) is p2, 3.31 g / cm 3 ≤ p2≤ 3.32 g / cm 3 .
10. The jig for suppressing sintering distortion of a magnetic material injection molded piece according to claim 7, wherein The shrinkage rate of the fixture body (1) is 1.19; The shrinkage rate of the magnetic material injection molded part (2) is 1.19.