A 3D printing sand core for core assembly

Abstract

The invention discloses a 3D printing sand core for core assembly. The 3D printing sand core comprises core bar embedding holes, sand filling holes, core bars and resin sand, wherein the plurality of core bar embedding holes are formed in a sand core body on the upper part of a sand core inner cavity; the core bar embedding holes extend in the sand core body in a horizontal direction; one core bar is fixedly mounted in each core bar embedding hole; a plurality of downward-extending sand filling holes are arranged on the positions, corresponding to each core bar embedding hole, on the upper surface of the sand core body; the sand filling holes are perpendicularly crossed and communicated with the core bar embedding holes; on each vertical section where the sand filling holes and the core bar embedding holes are crossed, the areas of the sand filling holes are greater than those of the core bar embedding holes, so that the core bar embedding holes and the core bars inside the core bar embedding holes are completely positioned in the sand filling holes; resin sand embedded from the sand filling holes is fed into an inner space formed by the sand filling holes and the core bar embedding holes after the core bars are inserted into the sand core embedding holes. According to the 3D printing sand core, the sand core are provided with the core bar embedding holes and the sand filling holes, and the resin sand is fed into the core bar embedding holes and the sand filling holes, so that the sand core is effectively connected to the core bars, and therefore, the integral strength of the sand core is improved, the core assembly requirements are met, and the quality of a casting piece is improved.

Description

technical field [0001] The invention belongs to the field of 3D printing sand cores for casting, and relates to a high-strength 3D printing sand core, in particular to a high-strength 3D printing sand core for core assembly. Background technique [0002] Core assembly (that is, core assembly molding) is a molding method that combines several sand cores to form a mold. It does not require sand boxes and other tooling, and is easy to operate and low in production costs. It is suitable for casting production of simple products. However, if the core assembly method is used to produce complex and medium / large products, the strength of the sand core itself cannot resist the pressure of the metal liquid, which will cause the sand core (mold) to crack and cause gunfire. [0003] At the same time, the rapid prototyping technology of 3D printing is a technology based on digital model files, using powder and other bondable materials to construct objects through layer-by-layer printing....

AI Technical Summary

Problems solved by technology

3D printing can be used to make sand molds and sand cores required for core assembly, but 3D printing can only produce a single material, and cannot compositely print sand, core bone, etc., and resin sand will fail at 300°C, while the temperature of pouring molten iron is at 1300°C Above, therefore, to produce complex, medium / large products by 3D core assembly method, it is necessary to strengthen the strength of 3D printing sand core

[0004] At present, the conventional way to improve the strength of ordinary sand cores in this field is to increase the core bone inside the sand core, such as the patent document with the publication number CN103769540A. Difficult, the above methods of strength enhancement are not widely used in 3D printing sand cores

[0005] In the 3D printing sand core, although there are very few contents related to this technology, such as the patent document with the publication number CN104707940A, but in this document, it is only for the simple high-temperature stamping sand core structure, and does not involve the combination of multiple sand cores. In the application of core assembly, due to the relatively simple design and installation of the core bone structure of the stamping sand core, when it is applied to the combination of multiple sand cores for the production of complex and large-scale products, the combination of the core bone and the sand core is unstable. The strength will not be improved or even reduced, resulting in the lack of practical application capabilities and not suitable for general core assembly requirements

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