阅读说明：本技术 一种较低水玻璃的含量的铸件造型工艺 (Casting molding process with low content of water glass ) 是由 谢康清 马治全 刘佩芳 赵贺龙 赵卫杰 姚松 于 2020-12-19 设计创作，主要内容包括：本发明提出了一种较低水玻璃的含量的铸件造型工艺,在铸造过程中采用面砂、背砂的造型方法,紧挨活件的砂型采用面砂,面砂为在原砂中加入占原砂比重3.7%-4.2%的水玻璃；远离活件的砂型和冒口箱砂型采用背砂,背砂为在再生砂中加入占比再生砂比重2.8%-3.5%的水玻璃；砂芯采用原砂加入3.8%-4.5%的水玻璃；采用了干起法,对砂型和砂芯进行点吹CO-2使砂型硬化后再进行起模和芯子脱盒。其有益效果是：在保证铸件质量的情况下水玻璃加入量大幅度降低,改善了水玻璃旧砂的硬度和溃散性,为实现水玻璃旧砂再生提供了便利条件；减少了水玻璃的用量,进而减少了企业购买水玻璃的成本；实现了硅砂的再回收利用,大大节约了铸造用硅砂这一不可再生资源。(The invention provides a casting molding process with lower water glass content, which adopts a molding method of facing sand and back sand in the casting process, wherein the sand mold next to a movable part adopts facing sand, and the facing sand is formed by adding water glass which accounts for 3.7-4.2% of the proportion of the raw sand into the raw sand; the sand mould far away from the movable part and the riser box sand mould adopt back sand, and the back sand is formed by adding water glass which accounts for 2.8-3.5% of the proportion of the reclaimed sand into the reclaimed sand; the sand core is made of raw sand and 3.8-4.5% of water glass is added; the dry lifting method is adopted to blow CO to the sand mould and the sand core 2 And after the sand mold is hardened, stripping and core stripping are carried out. The beneficial effects are as follows: the addition of the water glass is greatly reduced under the condition of ensuring the quality of the casting, the hardness and collapsibility of the used water glass sand are improved, and a convenient condition is provided for realizing the regeneration of the used water glass sand; the consumption of the water glass is reduced, and the cost of purchasing the water glass by enterprises is further reduced; realizes the recycling of the silica sand and greatly saves the casting costSilica sand is an irreproducible resource.)

1. A casting molding process with low water glass content is characterized in that: a molding method of facing sand and back sand is adopted in the casting process, the sand mold close to the movable part adopts facing sand, and the facing sand is formed by adding water glass which accounts for 3.7-4.2% of the proportion of the raw sand into the raw sand; the sand mould far away from the movable part and the riser box sand mould adopt back sand, and the back sand is formed by adding water glass which accounts for 2.8-3.5% of the proportion of the reclaimed sand into the reclaimed sand; the sand core is made of raw sand and 3.8-4.5% of water glass is added;

in the process of molding stripping and sand core box stripping, a dry stripping method is adopted to blow CO to the sand mold and the sand core₂And after the sand mold is hardened, stripping and core stripping are carried out.

2. A casting molding process with low water glass content as claimed in claim 1, characterized in that: the facing sand is prepared by adding water glass which accounts for 4 percent of the proportion of the raw sand into the raw sand.

3. A casting molding process with low water glass content as claimed in claim 1, characterized in that: the back sand is prepared by adding water glass which accounts for 3 percent of the proportion of the reclaimed sand into the reclaimed sand.

4. A casting molding process with low water glass content as claimed in claim 1, characterized in that: the sand core is made of raw sand and 4% of water glass is added into the raw sand.

Technical Field

The invention relates to the field of casting, in particular to a casting molding process with low water glass content.

Background

In order to change collapsibility of the sodium silicate-bonded sand, some manufacturers add a plurality of crumbling agents such as kaolin, limestone powder, iron oxide powder, magnesium oxide powder and the like during sand mixing separately or simultaneously. The collapsibility of the water glass sand is improved to a certain extent, but the effect is not obvious because the adding amount of the water glass is higher

The resin sand appeared in the later period has high hardening strength and good collapsibility. But the odor is pungent and has certain toxicity and the price is expensive, so that the application of the odor in a large scale is not realized.

In recent years, with the stricter requirements on environmental protection, research on nontoxic and odorless sodium silicate-bonded sand is promoted, and ester-hardened (organic ester) self-hardening sand is greatly influenced. The technology of adding modified water glass and organic ester (also called curing agent) into the self-hardening sand has great breakthrough in improving collapsibility, and the adding amount of the water glass is also lower. However, sand on the surface of the casting is not easy to fall off, and the subsequent procedure is difficult to shovel sand, the size precision of the casting is affected by the creep phenomenon of a sand mold (core), special baking equipment and the like are needed, even the casting is produced by matching with automatic production equipment, and the organic ester is expensive and needs certain investment. The cost is higher compared with the water glass CO2 hardened sand.

Most foundries still adopt the water glass sand CO2 hardening method to produce and manufacture.

The water glass CO2 hardened sand is the earliest method for gas hardening molding (core) for industrial application, and is still the main molding sand for steel casting production in China at present. Sodium silicate-bonded sand was regarded as important after the emergence of the CO2 hardening method in 1947. The CO2 hardening method of sodium silicate sand has various advantages of air hardening method modeling (core), but has the problems of poor collapsibility of molding sand, low hardening strength, difficult regeneration of used sand and the like, so that the application of the method is limited.

Disclosure of Invention

The invention provides a casting molding process with low water glass content to solve the problems in the prior art.

The technical scheme of the invention is realized as follows:

a casting molding process with low water glass content adopts a molding method of facing sand and back sand in the casting process, the sand mold next to a movable part adopts facing sand, and the facing sand is formed by adding water glass which accounts for 3.7-4.2% of the proportion of raw sand into the raw sand; the sand mould far away from the movable part and the riser box sand mould adopt back sand, and the back sand is formed by adding water glass which accounts for 2.8-3.5% of the proportion of the reclaimed sand into the reclaimed sand; the sand core is made of raw sand and 3.8-4.5% of water glass is added;

in the process of molding stripping and sand core box stripping, a dry stripping method is adopted to blow CO to the sand mold and the sand core₂And after the sand mold is hardened, stripping and core stripping are carried out.

Furthermore, the facing sand is prepared by adding water glass which accounts for 4 percent of the proportion of the raw sand into the raw sand.

Furthermore, the back sand is prepared by adding water glass which accounts for 3 percent of the specific weight of the reclaimed sand into the reclaimed sand.

Furthermore, the sand core is made of raw sand and 4% of water glass is added into the raw sand.

The beneficial effects are that:

1. under the condition of ensuring the quality of the casting, the adding amount of the water glass of the sand mold (core) is greatly reduced, the hardness and collapsibility of the used water glass sand are improved, and a convenient condition is provided for realizing the regeneration of the used water glass sand;

2. the consumption of the water glass is reduced, and the cost of purchasing the water glass by enterprises is further reduced;

3. the cooperation has the enterprise of sand regeneration facility, can better realize the recycle of grit, has practiced thrift this non-renewable resource of silica sand for the casting greatly, reduces or has avoided carrying out the environmental pollution that solid abandonment discharged and bring because of not good recycle.

Detailed Description

All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

A casting molding process with low water glass content adopts a molding method of facing sand and back sand in the casting process, the sand mold next to a movable part adopts facing sand, and the facing sand is formed by adding water glass which accounts for 3.7-4.2% of the proportion of raw sand into the raw sand; the sand mould far away from the movable part and the riser box sand mould adopt back sand, and the back sand is formed by adding water glass which accounts for 2.8-3.5% of the proportion of the reclaimed sand into the reclaimed sand; the sand core is made of raw sand and 3.8-4.5% of water glass is added;

the raw sand refers to used silica sand, and the reclaimed sand refers to used silica sand which is recycled.

In the process of molding stripping and sand core box stripping, a dry stripping method is adopted to blow CO to the sand mold and the sand core₂And (3) stripping and core stripping are carried out after the sand mold is hardened, and the strength of the sand mold can meet the requirement under the condition of lower compactness of the sand mold by a dry stripping method.

The sand mold has low compactness, can better realize the recycling of sand, greatly saves the non-renewable resource of silica sand for casting, and reduces or avoids the environmental pollution caused by solid waste discharge due to poor recycling.

Example one

The facing sand is prepared by adding water glass which accounts for 4 percent of the proportion of the raw sand into the raw sand.

The back sand is prepared by adding water glass which accounts for 3 percent of the proportion of the reclaimed sand into the reclaimed sand.

The sand core is made of raw sand and 4% of water glass is added into the raw sand.

The low water glass adding amount of the water glass sand mold is beneficial to the stripping of sand on the surface of a casting to a certain extent, obviously improves the difficult situation of recovering and crushing the used water glass sand, and provides possible conditions for the recycling of the sand.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.