Centralized production casting process for vortex-type castings

Abstract

A centralized casting process for vortex-type castings includes: S1) designing a molding mold for the vortex-type casting; S2) using a core box to heat and produce a sand core that matches the shape of the inner cavity of the vortex-type casting; S3) melting the raw materials required for making the vortex-type casting in a melting furnace; S4) installing the vortex-type casting mold produced in S1) on a molding machine to create a sand mold, and placing the sand core produced in S2) into a preset position within the sand mold; S5) using an automatic pouring method; S6) cooling the poured casting in a cooling drum, then rough-polishing it in a shot blasting machine, followed by grinding, and finally fine-polishing it in a shot blasting machine; S7) after rust prevention treatment, packaging and warehousing. This invention optimizes the casting process and centralizes production on a dedicated line, improving production efficiency, reducing production costs, and ensuring stable product quality, all tailored to the characteristics of vortex-type products.

Description

Technical Field

[0001] This invention belongs to the field of casting technology, specifically relating to a centralized production casting process for vortex-type castings. Background Technology

[0002] Scroll-type products are the main components of new-type inverter air conditioners. They are generally divided into moving plates and stationary plates. Their characteristic is that they have scroll-shaped protrusions or grooves, hence the name scroll-type products.

[0003] As market competition intensifies, raw material prices in the casting industry continue to rise, while product prices are declining, resulting in increasingly lower profit margins and a highly unfavorable situation for casting companies. Meanwhile, the demand for vortex castings is gradually increasing, with large casting companies currently maintaining a monthly output of over 300 tons. Simultaneously, due to the increasing variety and models of casting products, each production line undergoes an average of over 20 pattern changes per day, essentially every hour. Many products require different production conditions, necessitating frequent adjustments to production parameters and incurring additional waiting time. This leads to significant waste of energy, materials, and efficiency, and makes it difficult to maintain consistent product quality, resulting in low production efficiency. Summary of the Invention

[0004] In view of the above problems, the technical problem to be solved by the present invention is to provide a centralized production casting process for vortex-type castings, which centralizes the production of vortex-type products on a dedicated line, reduces production costs, improves production efficiency, and ensures stable product quality.

[0005] According to the technical solution of the present invention, the present invention provides a centralized production casting process for vortex-type castings, which mainly includes the following steps:

[0006] S1) Mold making: Use 3D modeling software to create a model of the vortex casting and design a mold for the shape required for the vortex casting;

[0007] S2) Core making: Red core sand dipped in paint with a Baumé degree of 40±5 is used to heat the core box to make a sand core that matches the shape of the inner cavity of the vortex casting.

[0008] S3) Smelting: The raw materials required for making vortex castings are placed in a smelting furnace for smelting. The raw materials consist of 40% high-manganese scrap steel and 60% recycled material from vortex castings.

[0009] S4) Molding: Install the vortex-type casting mold made in S1) onto the molding machine, use molding sand to make a sand mold, and place the sand core made in S2) into the preset position inside the sand mold;

[0010] S5) Casting: Automatic casting method is adopted. Casting begins when the temperature of molten iron in the furnace reaches 1410-1430℃. The final temperature is 1380℃. Temperature is measured twice for each ladle. The time from the ladle of molten iron to the completion of casting is controlled within 7 minutes.

[0011] S6) Post-processing: The casting obtained by casting is placed in a cooling drum for tumbling and cooling to separate the riser and gating from the casting; it is then placed in a shot blasting machine for rough blasting. After inspection, the casting that passes the initial test is ground and then placed in a shot blasting machine for fine blasting.

[0012] S7) Rust prevention treatment: After the finely polished castings are dipped in or sprayed with rust-preventive oil (using a sprayer), they are packaged and stored.

[0013] Furthermore, in S2), the curing temperature of the sand is 250±20℃, the curing time is 80-120 seconds, the sand shooting time is 3-5 seconds, and the sand shooting pressure is 0.5-0.7Mpa.

[0014] Furthermore, in S2), the red core sand is dipped in the coating and then ignited to ensure that the coating burns completely.

[0015] Furthermore, in S3), 70 kg of carbon raiser is pre-added into the smelting furnace.

[0016] Furthermore, during the smelting process, alloys such as manganese and copper are added. Generally, the manganese content is 0.9-1.0 wt%, the copper content is 0.4-0.5 wt%, the tin content is 0.07-0.08 wt%, the antimony content is 0.02-0.03 wt%, and the chromium content is 0.18-0.25 wt%. Then, the mixture is allowed to stand at a high temperature of 1520-1550℃ for 5-10 minutes.

[0017] Furthermore, 0.5 wt% silicon carbide is added for pretreatment before unloading. The pretreatment agent is added to the electric furnace and stirred to fully dissolve the pretreatment agent.

[0018] Furthermore, the performance requirements for S4 medium-sized sand are as follows: moisture content 2.8-3.3wt%, compaction rate 28-35%, air permeability 110-140, loss on ignition 3.0-4.0%, available soil 8-9wt%, and mud content 10-13wt%.

[0019] Furthermore, the rough blasting and fine blasting are performed using a suspended shot blasting machine.

[0020] Furthermore, the testing described in S6) includes testing the mechanical properties of the casting, such as hardness, metallographic structure, and tensile strength.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are as follows: A casting process for centralized production of vortex castings is designed, taking into account the structural characteristics of vortex casting products and the production processes such as core making, melting, and casting. This reduces the waiting time for mold changes, enables continuous large-scale centralized production of vortex castings, lowers production costs, improves production efficiency, optimizes the production process parameters on the centralized production line, and ensures the quality of vortex casting products. Detailed Implementation

[0022] The centralized production casting process for vortex-type castings according to the present invention mainly includes the following steps:

[0023] S1) Mold making: A model of the vortex casting is created using 3D modeling software, and a mold is designed to be used for the vortex casting. 3D modeling can make the mold more precise, laying a good foundation for subsequent processes, and thus making the blanks cast by the mold more accurate.

[0024] S2) Core making: Red core sand dipped in paint with a Baume degree of about 40 is used to make a sand core that matches the shape of the inner cavity of the vortex casting by heating with a core box; the curing temperature is maintained at about 250 degrees, the curing time is 100 seconds, the sand injection time is 3-5 seconds, and the sand injection pressure is 0.5-0.7 MPa.

[0025] S3) Smelting: The raw materials required for making vortex castings are placed in a smelting furnace for smelting. The raw materials consist of 40% high-manganese scrap steel and 60% recycled vortex castings. 70 kg of high-efficiency carbon raiser is added beforehand. During the smelting process, manganese-copper alloys are added, with manganese content of 0.9 wt%, copper content of 0.4 wt%, tin content of 0.07 wt%, antimony content of 0.02 wt%, and chromium content of 0.18 wt%. The mixture is then held at a high temperature of 1520-1530℃ for 5-8 minutes. Before tapping, 0.5 wt% silicon carbide is added for pretreatment. The pretreatment agent is added to the electric furnace and stirred to ensure that the pretreatment agent is fully dissolved.

[0026] S4) Molding: Install the vortex-type casting mold made in S1) onto the molding machine, use molding sand to make a sand mold, and place the sand core made in S2) into the preset position inside the sand mold; The performance requirements for molding sand are: moisture content 2.8-3.0wt%, compaction rate 28-32%, air permeability 130-140, loss on ignition about 3.0%, effective soil about 8wt%, and mud content 12wt%;

[0027] S5) Casting: Automatic casting is adopted. Casting begins when the temperature of molten iron in the furnace reaches 1410-1420℃, and the final temperature is 1380℃. If the temperature is too low, the iron is immediately returned to the furnace. The temperature of each ladle is measured twice, and the time from the ladle of molten iron to the completion of casting is controlled within 7 minutes.

[0028] S6) Post-processing: The casting obtained from the casting is placed in a cooling drum for tumbling and cooling, so that the riser and gating are separated from the casting; it is then placed in a shot blasting machine for rough polishing. After testing (generally testing mechanical properties such as hardness, metallography, and tensile strength), the casting that passes the preliminary test is ground to smooth out the burrs on the casting; it is then placed in a shot blasting machine for fine polishing to remove small impurities on the surface and make the surface of the casting smoother.

[0029] S7) Rust prevention treatment: After the finely polished castings are sprayed with special rust-preventive oil, they are packaged and put into storage.

[0030] As described above, in this embodiment, red core sand dipped in paint is used uniformly during the core-making process. After dipping in paint, it is ignited to ensure that the paint burns completely, allowing the effective substances to adhere to the surface of the sand core. It also keeps the sand core dry and extends its shelf life. Furthermore, baffles are added to the packaging box to reduce the impact damage to the sand core during transportation, improve the quality of the sand core, and solve the problem of scrap rate caused by the sand core.

[0031] This embodiment eliminates the conventionally used pig iron in the smelting process, using only high-manganese scrap steel and recycled materials from vortex castings. A highly efficient carbon raiser is added, and the tapping temperature is increased. A certain amount of silicon carbide is also added before tapping. This reduces raw material costs, decreases the probability of shrinkage, reduces the amount of alloy added, minimizes hardness fluctuations, and improves machinability.

[0032] Compared to the properties of molding sand used in conventional production molding, the parameters of molding sand in this embodiment are required to fluctuate more stably, so that the properties of molding sand have less impact on the entire production casting process, which is more conducive to ensuring the quality of casting products.

[0033] Compared to the manual casting machine used in conventional production, this embodiment uses mechanized automatic casting, which makes the casting stable and can effectively control the casting temperature and casting time. If the temperature is too low, the casting machine will immediately return the casting to the furnace, thus minimizing the impact of the casting machine's molten iron temperature on product quality.

[0034] Because vortex-type products have intricate and complex shapes, this embodiment removes the baffles inside the cooling drum used in conventional production to avoid collisions. A suspended shot blasting machine is used during shot blasting. This type of machine suspends the castings for shot blasting, preventing them from colliding with each other and minimizing damage. Furthermore, leather padding can be added inside the sheet metal used during transit to further protect the product and reduce damage to the castings during transportation.

Claims

1. A centralized production casting process for vortex-type castings, characterized in that, Includes the following steps: S1) Mold making: Use 3D modeling software to create a model of the vortex casting and design a mold for the shape required for the vortex casting; S2) Core making: Red core sand dipped in paint with a Baumé degree of 40±5 is used to heat the core box to make a sand core that matches the shape of the inner cavity of the vortex casting. S3) Smelting: The raw materials required for making vortex castings are placed in a smelting furnace for smelting. The raw materials consist of 40% high-manganese scrap steel and 60% recycled material from vortex castings. S4) Molding: Install the vortex-type casting mold made in S1) onto the molding machine, use molding sand to make a sand mold, and place the sand core made in S2) into the preset position inside the sand mold; S5) Casting: Automatic casting method is adopted. Casting begins when the temperature of molten iron in the furnace reaches 1410-1430℃. The final temperature is 1380℃. Temperature is measured twice for each ladle. The time from the ladle of molten iron to the completion of casting is controlled within 7 minutes. S6) Post-processing: The casting obtained by casting is placed in a cooling drum for tumbling and cooling to separate the riser and gating from the casting; it is then placed in a shot blasting machine for rough blasting. After inspection, the casting that passes the preliminary test is ground and then placed in a shot blasting machine for fine blasting. S7) Rust prevention treatment: After the finely polished castings are dipped in or sprayed with rust-preventive oil, they are packaged and put into storage; Among them, the curing temperature of sand making in S2) is 250±20℃, the curing time is 80-120 seconds, the sand shooting time is 3-5 seconds, and the sand shooting pressure is 0.5-0.7Mpa; In S2), the red core sand is dipped in the paint and then ignited to ensure the paint burns completely. S3) Pre-add 70 kg of carbon raiser into the smelting furnace; During the smelting process, an alloy is added, wherein the manganese content is 0.9-1.0 wt%, the copper content is 0.4-0.5 wt%, the tin content is 0.07-0.08 wt%, the antimony content is 0.02-0.03 wt%, and the chromium content is 0.18-0.25 wt%. Then, it is allowed to stand at a high temperature of 1520-1550℃ for 5-10 minutes. Before exiting the furnace, add 0.5 wt% silicon carbide for pretreatment.

2. The centralized production casting process for vortex-type castings as described in claim 1, characterized in that, The performance requirements for S4 medium-sized sand are as follows: moisture content 2.8-3.3%, compaction rate 28-35%, air permeability 110-140, loss on ignition 3.0-4.0%, available soil 8-9%, and mud content 10-13%.

3. The centralized production casting process for vortex-type castings as described in claim 1, characterized in that, The rough and fine shot blasting processes are performed using a suspended shot blasting machine.

4. The centralized production casting process for vortex-type castings as described in claim 1, characterized in that, The tests described in S6) include testing the hardness, metallographic properties, and tensile strength of the castings.