阅读说明：本技术 一种强化薄壁砂芯的制备方法 (Preparation method of reinforced thin-wall sand core ) 是由 陈秀明 刘庆义 姜爱龙 孙玉成 王福祥 于 2020-06-30 设计创作，主要内容包括：本发明公开了一种强化薄壁砂芯的制备方法,在制芯过程中,对砂芯需要强化的薄壁处采用覆膜砂与加强骨料混合的方式成型。由于加强骨料可以在砂芯的薄弱处起到骨料强化的作用,因此,可以有效避免薄壁砂芯在制芯、搬运、烘烤及浇注过程中造成的砂芯变形及断芯等问题,从而降低铸造缺陷。(The invention discloses a preparation method of a reinforced thin-wall sand core. The reinforced aggregate can play a role in reinforcing the aggregate at the weak part of the sand core, so that the problems of deformation, core breaking and the like of the sand core caused in the processes of core making, carrying, baking and pouring of the thin-wall sand core can be effectively avoided, and the casting defect is reduced.)

1. The preparation method of the reinforced thin-wall sand core is characterized in that in the core making process, the thin wall part of the sand core needing to be reinforced is formed by adopting a mode of mixing precoated sand and reinforcing aggregate.

2. The method for preparing the reinforced thin-wall sand core according to claim 1, wherein in the core making process, the thin wall of the sand core to be reinforced is shot by using prefabricated coated sand, wherein the prefabricated coated sand comprises: basic aggregate, reinforcing aggregate, binder, curing agent and lubricant.

3. The method for preparing the reinforced thin-wall sand core according to claim 2, wherein in the core making process, the prefabricated precoated sand is adopted to perform sand shooting on the thin wall of the sand core to be reinforced, and the reinforcing aggregate is sprayed at the same time.

4. The method for preparing the reinforced thin-wall sand core according to claim 2, wherein the prefabricated coated sand is adopted for sand shooting on the whole sand core in the core making process.

5. The method for preparing the reinforced thin-walled sand core of claim 2, wherein the pre-coated sand comprises: 100 parts by weight of base aggregate, 3-7 parts by weight of reinforcing aggregate, 2-4 parts by weight of binder, 0.35-0.5 part by weight of curing agent and 0.2-0.4 part by weight of lubricant.

6. The method for preparing the reinforced thin-walled sand core of claim 5, wherein the pre-coated sand comprises: 100 parts by weight of base aggregate, 5 parts by weight of reinforcing aggregate, 3 parts by weight of binder, 0.45 part by weight of curing agent and 0.3 part by weight of lubricant.

7. The method of claim 5, wherein the base aggregate is silica sand, the binder is phenolic resin or furan resin, the curing agent is an aqueous solution of urotropine, and the lubricant is calcium stearate.

8. The method for preparing the reinforced thin-wall sand core according to claim 1, wherein in the core making process, the reinforced aggregate is firstly placed at the thin wall of the sand core to be reinforced, and then the coated sand is injected at the thin wall of the sand core to be reinforced.

9. The method of any one of claims 1 to 8, wherein the reinforcing aggregate is carbon fiber, or asbestos fiber, or ceramic fiber, or glass fiber.

Technical Field

The invention relates to the technical field of casting, in particular to a preparation method of a reinforced thin-wall sand core.

Background

The sand core is a material for manufacturing a core in casting production and consists of casting sand, a molding sand binder and the like. The function is to form the inner cavity, the hole, the appearance and other parts of the casting. The process of making the core sand into the sand core conforming to the shape of the core box is called core making, and the core making is divided into manual core making and machine core making. The precoated sand is prepared by coating a layer of molding sand of a solid resin film on the surface of sand grains before molding and core making, and adding materials such as a latent curing agent (urotropine), a lubricant (calcium stearate) and the like into thermoplastic phenolic resin through a certain precoating process. The core box is a special mould for manufacturing the sand core and is divided into a common core box, a hot core box and a cold core box according to a core manufacturing method.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for preparing a reinforced thin-wall sand core, which can reinforce a local weak part of the sand core and avoid casting defects caused by insufficient strength of the sand core.

In order to achieve the purpose, the invention provides the following technical scheme:

a method for preparing a reinforced thin-wall sand core is characterized in that in the core making process, the thin wall of the sand core needing to be reinforced is formed in a mode of mixing precoated sand and reinforcing aggregate.

Preferably, in the core making process, the thin wall of the sand core to be strengthened is shot by using prefabricated coated sand, wherein the prefabricated coated sand comprises: basic aggregate, reinforcing aggregate, binder, curing agent and lubricant.

Preferably, in the core making process, the prefabricated precoated sand is adopted to perform sand shooting on the thin wall part of the sand core needing to be strengthened, and the reinforcing aggregate is sprayed at the same time.

Optionally, in the core making process, the prefabricated precoated sand is adopted for the whole sand core to perform sand shooting.

Preferably, the precoated sand includes: 100 parts by weight of base aggregate, 3-7 parts by weight of reinforcing aggregate, 2-4 parts by weight of binder, 0.35-0.5 part by weight of curing agent and 0.2-0.4 part by weight of lubricant.

Preferably, the precoated sand includes: 100 parts by weight of base aggregate, 5 parts by weight of reinforcing aggregate, 3 parts by weight of binder, 0.45 part by weight of curing agent and 0.3 part by weight of lubricant.

Preferably, the basic aggregate is silica sand, the binder is phenolic resin or furan resin, the curing agent is urotropine aqueous solution, and the lubricant is calcium stearate.

Preferably, in the core making process, the reinforcing aggregate is firstly placed at the thin wall of the sand core to be reinforced, and then the coated sand is injected at the thin wall of the sand core to be reinforced.

Optionally, the reinforcing aggregate is carbon fiber, or asbestos fiber, or ceramic fiber, or glass fiber.

According to the preparation method of the reinforced thin-wall sand core, in the core making process, the thin wall part of the sand core needing to be reinforced is formed in a mode of mixing the precoated sand and the reinforcing aggregate. The reinforced aggregate can play a role in reinforcing the aggregate at the weak part of the sand core, so that the problems of deformation, core breaking and the like of the sand core caused in the processes of core making, carrying, baking and pouring of the thin-wall sand core can be effectively avoided, and the casting defect is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a method of making a strengthened thin-wall sand core according to a second embodiment of the present invention;

fig. 2 is a schematic diagram of sand shooting at a thin wall of a sand core in the first embodiment of the present invention.

In fig. 2:

1-sand shooting nozzle, 2-core box inner cavity, 3-sand core thin wall, 4-jet nozzle, and 5-prefabricated precoated sand.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 and 2, fig. 1 is a flow chart of a method for preparing a reinforced thin-wall sand core according to an embodiment of the present invention; fig. 2 is a schematic diagram of sand shooting at a thin wall of a sand core in the embodiment of the present invention.

The invention provides a preparation method of a reinforced thin-wall sand core for manufacturing a core by mixing reinforced aggregate into precoated sand, aiming at the problem that the casting defect is easily caused by insufficient strength of a complex thin-wall sand core. The reinforced aggregate can play a role in reinforcing the aggregate at the weak part of the sand core, so that the problems of deformation, core breaking and the like of the sand core caused in the processes of core making, carrying, baking and pouring of the thin-wall sand core can be effectively avoided, and the casting defect is reduced.

The preparation method provided by the scheme can be implemented in various ways according to different modes of mixing the reinforcing aggregate into the precoated sand. Please refer to the following embodiments.