Sintering jig for swing arm type MIM parts
By setting up co-fired parts in the sintering fixture of metal injection molded swing arm type MIM parts and using de-fired parts to remove co-fired parts, the problem of easy cracks and size fluctuations in the sintering process is solved, and a high-precision and low-cost production effect is achieved.
Patent Information
- Application Number
- CN202421760229.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-24
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-07-24
AI Technical Summary
Existing metal injection molded swing arm MIM parts are prone to cracks and dimensional fluctuations during degreasing and sintering, and have high production costs and are not widely applicable.
A sintering fixture for swing arm MIM parts is designed. By setting cofired parts at the lower part of the suspended position of the product injection molding embryo, and using a defired fixture to remove cofired parts before shaping, replacing the traditional ceramic plate and connecting material structure.
It effectively improves the cracks of parts during sintering, improves the dimensional accuracy and quality of the product, reduces production costs, and is suitable for mass production.
Smart Images
Figure CN222754424U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to a sintering fixture for metal injection molding parts, in particular to a sintering fixture for swing arm type MIM parts. Background Art
[0002] There is a type of metal injection molded swing arm MIM parts, whose individual areas are not on the same plane as the main body. Currently, there are two main methods for production and processing: the first method is to use specific alumina ceramic plates to support the firing during the degreasing and sintering process to reduce the degree of deformation of the product; the second method is to add a connecting structure to the suspended position of the product to ensure that it remains flush with the large surface, and remove it through CNC after sintering.
[0003] Method 1: If Figure 1 As shown, the specific ceramic plate 2 needs to be designed with a boss 21 in accordance with the requirements of the part structure. In order to ensure that the product shrinkage is not affected, a gap will be left between the part and the ceramic plate, which leads to a partial risk of breakage of the part during the degreasing stage. At the same time, the ceramic plate has high hardness and is difficult to process, resulting in poor dimensional accuracy and large dimensional fluctuations, which causes cracks in the MIM parts during the degreasing process and the transfer process. During the sintering process, it is affected by shrinkage, resulting in large dimensional fluctuations and large deformation of the parts.
[0004] Method 2: Add a material connection structure in the suspended position. This structure can ensure that the product will not crack during the degreasing and sintering process, and also ensure the size. However, the post-process needs to be removed by CNC, which is too costly and the material turnover time is not long. Utility Model Content
[0005] In view of the above-mentioned problems, the utility model provides a sintering fixture for swing arm type MIM parts, which can save costs, improve cracks or deformation occurring during the processing, and improve quality.
[0006] To this end, the utility model adopts the following technical solution: a sintering fixture for swing arm-type MIM parts, including a fixing part for fixing the product injection molded embryo, characterized in that a co-fired part is arranged at the lower part of the suspended position of the product injection molded embryo, and a co-fired part removal fixture matching the shape of the co-fired part is arranged at the outer end of the co-fired part.
[0007] Preferably, the co-fired part is made of MIM material having the same shrinkage rate as the product.
[0008] Preferably, the cross-section of the co-fired component is an isosceles trapezoid.
[0009] Preferably, the jig for removing the co-fired parts comprises a main body, and an inner end of the main body forms a hollow groove matching the co-fired parts.
[0010] Preferably, the fixing member comprises an upper profiling fixing block and a lower profiling fixing block, and the product injection molded embryo is arranged in a profiling area formed between the upper profiling fixing block and the lower profiling fixing block.
[0011] Preferably, the lower profiling fixing block is a multi-stage stepped block structure, the upper profiling fixing block is stacked on the lower profiling fixing block, and the co-fired piece removal fixture is arranged at the outer end of the fixing block.
[0012] Preferably, the suspended position of the injection molded product is below the front arc position.
[0013] Preferably, the bottom surface of the co-fired part is flush with the bottom surface of the main body of the injection molded product.
[0014] The utility model designs and processes corresponding co-fired MIM parts by sorting out the structure and production characteristics of swing arm MIM parts, replacing special ceramic plates and connecting material scheme structures, and sintering by co-firing. Before shaping, the co-fired parts are removed by manual cooperation with the co-fired parts removal fixture, which will not damage the product and can also ensure the size and yield of the product.
[0015] The utility model can improve the situation of product cracks, enhance the product size accuracy, reduce production costs, and is suitable for batch production. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the structure of a traditional ceramic plate support.
[0017] Figure 2 Schematic diagram of setting a co-fired part at the lower part of the suspended position of the injection molded product.
[0018] Figure 3 Schematic diagram of the overall structure of the sintering fixture.
[0019] Figure 4 for Figure 3 main view.
[0020] Figure 5 Schematic diagram of the structure of the jig for removing the co-fired parts.
[0021] In the figure: 1. Product injection molded embryo 2. Ceramic cup 3. Co-fired part 4. Arc position 5. Lower profiling fixing block 6. Upper profiling fixing block 7. Co-fired part removal fixture 8. Empty slot. DETAILED DESCRIPTION
[0022] The present invention is further described below in conjunction with specific embodiments.
[0023] like Figure 2-Figure 5The sintering fixture of a swing arm type MIM part shown in the figure includes a fixing part for fixing the product injection molded embryo 1, a co-fired part 3 is arranged at the lower part of the suspended position of the product injection molded embryo, and a co-fired part removal fixture 7 matching the co-fired part shape is arranged at the outer end of the co-fired part 3. The height of the product suspended position is generally consistent with the height of the co-fired part. In order to stabilize the size of the part after co-firing, the ejector pin mark on the surface of the co-fired part is only allowed to be low, not high. The suspended position of the product injection molded embryo 1 is below the front arc position 4. The bottom surface of the co-fired part 3 is flush with the bottom surface of the main body of the product injection molded embryo 1.
[0024] Specifically, in order to ensure that the shrinkage effect of the parts and the co-fired parts is consistent, the co-fired part 3 uses MIM material with the same shrinkage rate as the product. At the same time, the injection molding of the co-fired parts needs to control: injection density, unit weight, and size.
[0025] In one embodiment, in order to ensure the stable placement of the co-fired component and reduce sticking on the side, the cross-section of the co-fired component 3 is designed to be an isosceles trapezoid.
[0026] Specifically, the jig for removing the co-fired parts includes a main body, and the inner end of the main body forms a hollow groove 8 matching the co-fired parts. Specifically, the fixing part includes an upper profiling fixing block 6 and a lower profiling fixing block 5, and the product injection molded embryo 1 is arranged in a profiling area formed between the upper profiling fixing block and the lower profiling fixing block. The upper and lower profiling fixing blocks are used to position the product.
[0027] Specifically, the lower profiling fixing block 5 is a multi-stage stepped block structure, the upper profiling fixing block 6 is stacked on the lower profiling fixing block 5, and the co-fired component removal jig 7 is arranged at the outer end of the fixing block. The co-fired component removal jig is used to separate the co-fired component from the outer end parts.
[0028] The specific production process is as follows: When making ornaments, use conventional flat alumina ceramic plates, first place the co-fired part injection-molded embryo on the ceramic plate, and then place the swing arm parts injection-molded embryo, with the corresponding arc position placed on the upward plane of the co-fired part; after the ornaments are completed, the combined products are degreased, sintered, and solution-treated together. Before shaping, use a special removal jig, and use contoured upper and lower fixing blocks to fix the product to prevent deformation when removing the connecting material, and then use a co-fired part removal jig to separate the co-fired part and the parts; thereby achieving the purpose of co-firing and ensuring the size of the product.
[0029] Based on the sintering characteristics of MIM parts, the utility model designs a sintering fixture specifically to replace the special ceramic plate and the supporting structure. The utility model has strong versatility and provides more guarantees for improving the sintering dimensional accuracy of the product. At the same time, the cost is relatively low and it is suitable for batch production.
[0030] It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.
Claims
1. A sintering fixture for swing arm type MIM parts, comprising a fixing part for fixing the injection molded product embryo (1), characterized in that A co-fired part (3) is arranged at the lower part of the suspended position of the injection-molded product, and a co-fired part removal fixture (7) matching the co-fired part's appearance is arranged at the outer end of the co-fired part (3).
2. A sintering fixture for swing arm MIM parts according to claim 1, characterized in that The co-fired part (3) is made of MIM material with the same shrinkage rate as the product.
3. A sintering fixture for swing arm MIM parts according to claim 1 or 2, characterized in that The cross section of the co-fired component (3) is an isosceles trapezoid.
4. A sintering fixture for swing arm MIM parts according to claim 3, characterized in that The jig for removing the co-fired parts comprises a main body, the inner end of which is formed with a hollow groove (8) matching the co-fired parts.
5. The sintering fixture for swing arm MIM parts according to claim 4, characterized in that The fixing member comprises an upper profiling fixing block (6) and a lower profiling fixing block (5), and the product injection molded embryo (1) is arranged in a profiling area formed between the upper profiling fixing block and the lower profiling fixing block.
6. The sintering fixture for swing arm MIM parts according to claim 5, characterized in that The lower profiling fixing block (5) is a multi-stage stepped block structure, the upper profiling fixing block (6) is stacked on the lower profiling fixing block (5), and the co-fired piece removal jig (7) is arranged at the outer end of the fixing block.
7. The sintering fixture for swing arm MIM parts according to claim 1, characterized in that The suspended position of the product injection molded embryo (1) is below the front arc position (4).
8. The sintering fixture for swing arm MIM parts according to claim 1, characterized in that The bottom surface of the co-fired part (3) is flush with the bottom surface of the main body of the injection molded product (1).