Automatic silica sol ceramic sand quick-drying shell making process for precision casting

Abstract

The invention relates to the related technical field of precision casting, in particular to an automatic silica sol quartz sand quick-drying shell making process for precision casting. The invention discloses an automatic silica sol quartz sand quick-drying shell making process for precision casting, which comprises the following steps: mixing silica sol according to a specific ratio, automatically making shells, operating by a manipulator, performing three groups each time, performing 2 minutes for each group, and performing air drying for 3-4 hours to complete shell making. Through automatic operation, the labor intensity is reduced by more than 60%, the production efficiency is improved by more than 50%, and the first-pass yield of products is improved by more than 30%; the low-cost quartz sand is adopted to replace mullite sand, natural air drying is combined, the material cost and the energy consumption are both saved by 30% or above, and the silica sol is environmentally friendly, free of harm, capable of meeting the national environmental requirements, suitable for production of various castings and easy to popularize.

Description

Technical Field

[0001] This invention relates to the field of precision casting technology, and in particular to an automated process for quick-drying silica sol quartz sand shell making for precision casting. Background Technology

[0002] In the field of precision casting, low-temperature wax silica sol precision casting process is widely used because it can produce castings with complex shapes and high dimensional accuracy. The shell-making process is a key link in this casting process, and its quality and efficiency directly affect the quality of the castings and production efficiency.

[0003] Traditional shell-making processes rely heavily on manual labor, resulting in high worker intensity. Furthermore, manual operation is limited to single-team work, with each team completing approximately two minutes of work, leading to low production efficiency. Additionally, the uniformity and stability of the shells produced are poor due to unpredictable human factors, resulting in a low first-pass yield. In terms of materials, traditional processes primarily use mullite, which costs approximately 1500 yuan per ton, making material costs relatively high. Moreover, traditional water glass and ammonium chloride hardening processes pose certain environmental hazards and do not comply with increasingly stringent national environmental regulations.

[0004] In order to meet the upgraded requirements of national environmental management, foundries urgently need a shell-making process that can save energy, reduce consumption, and increase efficiency. Therefore, developing a shell-making process that is highly automated, energy-saving, environmentally friendly, low-cost, and can improve product quality is of great practical significance. Summary of the Invention

[0005] The purpose of this invention is to provide an automated quick-drying shell-making process using silica sol quartz sand for precision casting, in order to solve the problems mentioned in the background art. Traditional shell-making processes mostly rely on manual operation, resulting in high labor intensity for workers. Furthermore, manual operation can only be carried out in single groups, with each group's operation time being approximately 2 minutes, leading to low production efficiency. At the same time, due to the influence of uncertain human factors, the uniformity and stability of the shell-making process are poor, resulting in a low first-pass yield. In terms of materials, traditional processes mostly use mullite as the main material, which has a market price of approximately 1500 yuan / ton, resulting in high material costs.

[0006] To achieve the above objectives, the present invention provides the following technical solution: the shell-making process includes the following steps:

[0007] Step 1: Raw material preparation. Prepare materials according to the following ratio: 100Kg silica sol (specification model 1430), 200Kg mullite powder (200 mesh), 0.2Kg quick-drying agent, 5Kg purified water, and quartz sand (60-80 mesh, 30-60 mesh, 10-20 mesh, added according to the size of the sand casting machine); the silica content of the quartz sand is above 95%, and its density, bulk density, compressive strength, roundness, sphericity, breakage rate, solubility rate, and thermal stability meet the physical performance indicators for precision casting. The heat resistance is 1700℃-1900℃, and the particle size distribution is divided into low density, medium density, and high density grades according to the bulk density.

[0008] Step 2: Mixing. Add silica sol, mullite powder, quick-drying agent, and purified water to the mixing equipment and stir evenly to form a shell-forming slurry.

[0009] Step 3: Automated shell making. The low-temperature wax mold is immersed in the shell making slurry prepared in step 2 by a robotic arm. After being taken out, quartz sand is evenly coated on the surface of the wax mold by a sand spraying machine to form a reinforcing layer. The mechanical operation is carried out in three groups each time, and the operation time of each group is 2 minutes.

[0010] Step 4: Air drying. Place the wax mold after shell making in a ventilated environment to air dry for 3-5 hours to obtain a precision cast shell model.

[0011] In step 1, the specifications and types of quartz sand are selected according to production requirements. At least one of the following can be used: 10-20 mesh, 16-20 mesh, 16-30 mesh, 20-40 mesh, 30-50 mesh, 40-60 mesh, 60-80 mesh, and 80-100 mesh.

[0012] In step 2, the mixing speed of the mixing equipment is 300-500 r / min, and the mixing time is 15-30 minutes.

[0013] In step 3, the sand-spraying pressure of the sand-spraying machine is 0.2-0.3MPa to ensure that the quartz sand is evenly covered on the surface of the wax mold.

[0014] In step 4, the temperature of the air-drying environment is 20-25℃ and the humidity is 40%-60%.

[0015] A shell-making material composition comprises the following components: 100 kg of silica sol, 200 kg of mullite powder, 0.2 kg of quick-drying agent, 5 kg of purified water, and quartz sand; wherein the silica content of the quartz sand is above 95%, and it has a heat resistance of 1700℃-1900℃.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] The automated operation using robotic arms can simultaneously complete three sets of shell-making operations each time, with each set taking only 2 minutes. Compared to the traditional manual single-set operation mode, this directly reduces labor intensity by more than 60% and increases production efficiency by more than 50%, effectively solving the problems of low efficiency and heavy labor load associated with manual operation. The automated sand-spraying system eliminates the uncertainty of manual operation by precisely controlling the sand-spraying pressure and the uniformity of quartz sand coverage, combined with a stable slurry ratio, increasing the first-pass yield rate by more than 30%. At the same time, the high heat resistance (1700℃-1900℃) and excellent physical properties of the quartz sand with a content ≥95% ensure the structural stability of the shell mold during high-temperature casting, reducing casting defects.

[0018] In terms of material costs: Quartz sand, which has a lower market price, is used to replace mullite sand, and with optimized material ratios, material costs are directly saved;

[0019] In terms of energy consumption: natural air drying for 3-5 hours replaces the high-temperature drying of traditional hardening processes, and the energy consumption of the automated system is controllable, saving more than 30% of energy overall, which is in line with the energy conservation and carbon reduction trend in the manufacturing industry. In addition, different specifications of quartz sand, such as 10-20 mesh to 80-100 mesh, can be flexibly selected according to production needs, which is suitable for the shell making needs of various castings. Moreover, it can maintain stable product quality in both pilot and large-scale production, and is easy to promote and apply in the industry. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the shell-making material composition in the silica sol-quartz sand rapid-drying shell-making process of the present invention.

[0021] Figure 2 This is a schematic diagram of the automated silica sol quartz sand fast-drying shell-making process of the present invention. Detailed Implementation

[0022] Example 1

[0023] Operate according to the process of claim 1.

[0024] Prepare the following raw materials: 100 kg of silica sol (1430), 200 kg of mullite powder (200 mesh), 0.2 kg of quick-drying agent (NP), 5 kg of purified water, and 60-80 mesh quartz sand (added according to the size of the sandblasting machine). The quartz sand has a content of 96%, a heat resistance of 1800℃, and all physical properties meet the requirements.

[0025] Mixing: Add the above raw materials to the mixing equipment and stir at a speed of 400 r / min for 12 minutes to obtain the shell-forming slurry.

[0026] Automated shell making: The low-temperature wax mold is immersed in the slurry by a robotic arm, and after being taken out, it is coated with 60-80 mesh quartz sand by a sand-spraying machine (sand-spraying pressure 0.25MPa). The mechanical operation is carried out in three groups at a time, with each group operating for 2 minutes.

[0027] Air drying: Place the wax mold after shell making in a ventilated environment at 22℃ and 50% humidity for 3.5 hours to air dry, and obtain the shell shape.

[0028] This process reduces labor intensity by 65%, increases product first-pass yield by 32%, saves energy by 31%, and reduces material costs by 33%.

[0029] Example 2

[0030] It is basically the same as Example 1, except that 30-60 mesh quartz sand is used.

[0031] The quartz sand content is 95.5%, the heat resistance is 1750℃, and all physical properties meet the requirements.

[0032] Mixing speed 350 r / min, mixing time 14 minutes, sand rinsing pressure 0.2 MPa.

[0033] Air drying time: 3 hours, ambient temperature: 23℃, humidity: 45%.

[0034] This process reduces labor intensity by 62%, increases product first-pass yield by 30%, saves energy by 30%, and reduces material costs by 31%.

[0035] Example 3

[0036] Use 10-20 mesh quartz sand, and refer to Example 1 for other process parameters.

[0037] The quartz sand content is 95.8%, the heat resistance is 1850℃, and the physical performance indicators meet the standards.

[0038] Mixing speed 450 r / min, mixing time 10 minutes, sand rinsing pressure 0.3 MPa.

[0039] Air-drying environment temperature 20℃, humidity 60%, air-drying time 4 hours.

[0040] This process reduces labor intensity by 63%, increases product first-pass yield by 31%, saves energy by 32%, and reduces material costs by 32%.

[0041] Example 4

[0042] Mixed-size quartz sand (60-80 mesh and 30-60 mesh mixed in a 1:1 ratio) is used.

[0043] Mixing speed 380 r / min, mixing time 13 minutes, sand spraying pressure 0.27 MPa.

[0044] Air drying temperature 24℃, humidity 48%, air drying time 3.2 hours.

[0045] It reduces workers' labor intensity by 64%, increases product first-pass yield by 33%, saves energy by 30%, and reduces material costs by 34%.

[0046] Comparative Example 1 (Traditional Manual Operation Process)

[0047] Traditional manual operation was adopted, using mullite (market price 1500 yuan / ton), and the material ratio and other process parameters were kept as consistent as possible with those in Example 1.

[0048] The operation is carried out manually in single groups, with each group taking approximately 2 minutes.

[0049] After shelling, traditional drying methods are used, which takes a long time.

[0050] The labor intensity of workers is high, the first-pass yield of products is more than 30% lower than that of Example 1, the energy consumption is more than 30% higher than that of Example 1, the material cost is more than 30% higher than that of Example 1, and due to human factors, the uniformity and stability of shell making are poor.

[0051] Comparative Example 2 (Traditional water glass and ammonium chloride hardening process)

[0052] It employs a water glass and ammonium chloride hardening process, and uses traditional materials.

[0053] This process has a certain impact on the environment and produces an irritating odor.

[0054] The drying time is long and the production efficiency is low.

[0055] The product quality stability is not as good as that of Example 1, and it does not meet national environmental protection requirements, with higher material costs and energy consumption.

[0056] Comparative Example 3 (Semi-automated process)

[0057] Some steps are done manually, while others are automated. Quartz sand is used as the material.

[0058] Manual feeding and automated sand spraying are used, with two sets of operations per run, each set taking 2.5 minutes to operate.

[0059] Air drying time: 3.8 hours.

[0060] The labor intensity of workers is 25% higher than that of Example 1, the first-pass yield of products is 12% lower than that of Example 1, the energy consumption is 10% higher than that of Example 1, and the overall efficiency is not as good as that of the fully automated process.

[0061] Comparative Example 4 (process without added fast-drying agent)

[0062] The process steps are basically the same as in Example 1, but no fast-drying agent is added.

[0063] The shell-forming slurry has slightly poor fluidity, which affects the uniformity of sand leaching.

[0064] The air-drying time is extended to 5-6 hours.

[0065] The first-pass yield of the product was 8% lower than that of Example 1, and energy consumption increased by 8% due to the extended drying time, resulting in a decrease in production efficiency.

[0066] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An automated process for rapid drying of silica sol quartz sand for precision casting, characterized in that, The shell-making process includes the following steps: Step 1: Raw material preparation. Prepare materials according to the following ratio: 100Kg silica sol (specification model 1430), 200Kg mullite powder (200 mesh), 0.2Kg quick-drying agent, 5Kg purified water, and quartz sand (60-80 mesh, 30-60 mesh, 10-20 mesh, added according to the size of the sand casting machine); the silica content of the quartz sand is above 95%, and its density, bulk density, compressive strength, roundness, sphericity, breakage rate, solubility rate, and thermal stability meet the physical performance indicators for precision casting. The heat resistance is 1700℃-1900℃, and the particle size distribution is divided into low density, medium density, and high density grades according to the bulk density. Step 2: Mixing. Add silica sol, mullite powder, quick-drying agent, and purified water to the mixing equipment and stir evenly to form a shell-forming slurry. Step 3: Automated shell making. The low-temperature wax mold is immersed in the shell making slurry prepared in step 2 by a robotic arm. After being taken out, quartz sand is evenly coated on the surface of the wax mold by a sand spraying machine to form a reinforcing layer. The mechanical operation is carried out in three groups each time, and the operation time of each group is 2 minutes. Step 4: Air drying. Place the wax mold after shell making in a ventilated environment to air dry for 3-5 hours to obtain a precision cast shell model.

2. The automated silica sol-based rapid-drying shell-making process for precision casting according to claim 1, characterized in that, In step 1, the specifications and types of quartz sand are selected according to production requirements. At least one of the following can be used: 10-20 mesh, 16-20 mesh, 16-30 mesh, 20-40 mesh, 30-50 mesh, 40-60 mesh, 60-80 mesh, and 80-100 mesh.

3. The automated silica sol-based rapid-drying shell-making process for precision casting according to claim 1, characterized in that, In step 2, the mixing speed of the mixing equipment is 300-500 r / min, and the mixing time is 15-30 minutes.

4. The automated silica sol-based rapid-drying shell-making process for precision casting according to claim 1, characterized in that, In step 3, the sand-spraying pressure of the sand-spraying machine is 0.2-0.3MPa to ensure that the quartz sand is evenly covered on the surface of the wax mold.

5. The automated silica sol-based rapid-drying shell-making process for precision casting according to claim 1, characterized in that, In step 4, the temperature of the air-drying environment is 20-25℃ and the humidity is 40%-60%.

6. A shell-making material composition as described in any one of claims 1-5, and an automated silica sol-quartz sand fast-drying shell-making process for precision casting, characterized in that... It is composed of the following components: 100 kg of silica sol, 200 kg of mullite powder, 0.2 kg of quick-drying agent, 5 kg of purified water, and quartz sand; the silica content of the quartz sand is above 95%, and it has a heat resistance of 1700℃-1900℃.

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