Casting process method of marine bow casting

Abstract

The invention relates to the technical field of casting of ship bow castings, in particular to a casting process method of a ship bow casting, which comprises the following steps: generating a three-dimensional model of the bow casting through software, performing structural analysis on the three-dimensional model, formulating a casting process scheme by using casting analysis software, and adopting a process scheme of a cantilever core and a positioning core head. The method has the beneficial effects that the problems of dimensional deviation and deformation of the produced thin-wall special-shaped bow casting are solved, the size of the sand mold is controllable, the quality of the casting is improved, the production cost is reduced, and the production efficiency is improved. And the production efficiency of the bow casting is improved, and the production share of marine parts is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of marine bow casting, and particularly relates to a casting process method for marine bow castings. Background Art

[0002] In marine castings, the special-shaped bow has a complex structure and a thin-wall structure, making the casting extremely difficult. The marine bow casting has an L-shaped + semi-circular + multiple ribbed plate structure, and the thickness of the ribbed plates varies from 25 to 50 mm. It is difficult to control the wall thickness with conventional casting methods. At the same time, it is a curved profile structure, and it is difficult to control the casting deformation, and it is difficult to control the shape, making it difficult to meet the user's requirements.

[0003] For a long time, for castings such as marine bows, the empirical casting method is usually adopted. By repeatedly modifying the casting blank by foundry workers, the dimensional and precision requirements of marine bow castings can be achieved. This casting method has high requirements for the experience of foundry workers, low casting efficiency, and low casting yield, greatly restricting the casting productivity. Therefore, in order to improve the casting production efficiency, simplify the complexity of on-site operation links, further improve the production capacity of castings, and improve the market competitiveness and production share of various marine castings, it is necessary to carry out quality research on the process and innovation of thin-wall castings with difficult molding and complex structures such as marine bows. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a casting process method for marine bow castings. By generating a three-dimensional model of the bow casting through software and performing structural analysis on the three-dimensional model, a casting process plan is formulated using casting analysis software. The process plan of using a cantilever integral core + positioning core head is adopted, and core support hard point struts are used to prevent core lifting and avoid uneven thin-wall thickness; casting process tracking control is adopted, and the casting sand mold is corrected according to the feedback of the first finished bow casting, solving the problems of dimensional deviation and deformation of thin-wall special-shaped bow castings. The size of the sand mold is controllable, the quality of the casting is improved, the production efficiency of the bow casting is improved, and the production share of marine parts is increased.

[0005] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] A casting process method for marine bow castings, the casting process method includes the following contents:

[0007] S1: Use three-dimensional software to generate a three-dimensional stereoscopic structure diagram of the bow casting, and at the same time perform structural profile analysis on the shapes of its various parts;

[0008] S2: According to the structural characteristics of the bow casting, through simulation with casting software, perform simulation of the casting process plan, simulating filling, solidification, and stress deformation;

[0009] S3: Set the shrinkage rates of the casting processes for different parts, with a stretching scale of 10‰ - 12‰ at the opening ribs and 18‰ - 20‰ for the rest, and set different amounts of process grinding and correction;

[0010] S4: Adopt the process plan of cantilever core + positioning core head, and fabricate the integral cantilever sand core according to the casting process design; Based on the three-dimensional solid structure characteristics of the bow casting generated by the software, calculate the core head counterweight and stabilize the core setting; The core head of the integral cantilever sand core adopts a positioning core head structure to ensure the accuracy of core setting during the mold closing process and the control of the mold closing dimensions;

[0011] S5: Fabricate a split solid pattern wooden mold according to the integral cantilever sand core and the positioning core head structure, and assist in checking the wall thickness of the casting surface after core setting using a curved surface template;

[0012] S6: Design and fabricate a formed core iron according to the streamline structure of the integral cantilever sand core;

[0013] S7: Calculate the weight of the integral cantilever sand core and cooperate with the setting of core support hard point struts;

[0014] S8: Design and fabricate a formed general-purpose sand box;

[0015] S9: Track the on-site casting production and strengthen the process control;

[0016] S10: After finishing and removing the sand box, use a total station to mark the bow casting of the first piece removed from the sand box to determine the casting deformation, correct the sand core and the sand box, and then adjust the casting process parameters to meet the structural requirements of the bow casting;

[0017] S11: According to the flaw detection requirements, detect the first-piece bow casting to confirm whether there are defects inside the sand box. If there are internal defects, repair the internal defects of the sand box in a timely manner.

[0018] Further, in step S1, the three-dimensional model of the bow casting is a thin-walled special-shaped structure, the thin-walled dimension is 25 - 50 mm, and the special-shaped structure is a mixed structure of L-shaped + arc-shaped.

[0019] Further, in step S3, the amount of process grinding and correction for the thin-walled structure is 3 - 5 mm.

[0020] Further, in step S3, the amount of process grinding and correction for the non-machined surface is 5 - 15 mm.

[0021] Further, in step S4, one end of the integral cantilever sand core is provided with a positioning core head, and the other end is suspended without a core head.

[0022] Further, in step S4, the positioning core head structure is a single-sided right angle.

[0023] Further, the chaplet hard point strut in step S7 is arranged between the integral cantilever core and the top of the sand box.

[0024] Further, the formed core iron in step S6 is arranged inside the integral cantilever core.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1) Solve the problems of dimensional deviation and deformation of thin-walled special-shaped bow castings. Through the innovation of the process method, the production process of the castings is simplified, the deformation of the castings is controlled, the dimensions of the castings are guaranteed, and the quality, service life and dimensional accuracy of the castings are improved;

[0027] 2) Generate a casting model using 3D modeling software, conduct a structural analysis of the model, and formulate the dimensions of the sand mold, making the dimensions of the sand mold controllable, the dimensions of core setting during mold closing more controllable and accurate, reducing the dimensional deviation of the castings, and avoiding casting defects such as sand dropping;

[0028] 3) Simplify the complexity of on-site operation procedures, reduce the technical requirements for casting personnel, improve casting efficiency, reduce casting costs, increase the finished product rate of castings, improve the production efficiency of castings, expand the casting production capacity;

[0029] 4) Summarize the casting process plan for marine special-shaped bow castings, meet the detection requirements of non-destructive flaw detection for the overall special-shaped bow castings of users, improve the production efficiency of special-shaped thin-walled castings, increase the production share of marine parts in the market, and improve economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the three-dimensional schematic diagram of the marine bow described in the present invention.

[0031] Figure 2 is the side view of the marine bow described in the present invention.

[0032] Figure 3 is the structural schematic diagram of the integral cantilever core Figure 1 .

[0033] Figure 4 is the structural schematic diagram of the integral cantilever core Figure 2 .

[0034] Figure 5 is the structural grid schematic diagram of the integral cantilever core wooden mold

[0035] In the figure: 1. Bow casting; 2. Integral cantilever core; 3. Positioning core head structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following further describes the specific implementation manners of the present invention in conjunction with the accompanying drawings:

[0037] As Figures 1 - 5 shown, a casting process method for a marine bow casting, the casting process method includes the following contents:

[0038] S1: Use SolidWorks software to generate a three-dimensional solid structure diagram of the bow casting 1, and at the same time perform structural profile analysis on the shapes of its various parts;

[0039] S2: According to the structural characteristics of the bow casting 1, through Magama simulation, perform casting process plan simulation, simulate filling, solidification, and stress deformation, and finally determine the casting process plan for the full-scale pattern molding;

[0040] S3: Set the casting process shrinkage rates for different parts, with a draw ratio of 10‰ - 12‰ at the open ribs and 18‰ - 20‰ for the rest, and set different process grinding and correction amounts to ensure deformation and subsequent grinding;

[0041] S4: Adopt the process plan of a cantilever core + positioning core head. According to the casting process design, fabricate the integral cantilever core 2 to ensure the core strength and the core setting accuracy; according to the three-dimensional solid structure characteristics of the bow casting 1 generated by SolidWorks software, calculate the core head counterweight to stably set the core; the core head of the integral cantilever core 2 adopts the positioning core head structure 2 to ensure the accuracy of core setting during the core setting process and the control of the core setting dimensions;

[0042] S5: Fabricate a split full-scale wooden pattern according to the integral cantilever core 2 and the positioning core head structure 3, and assist in using a curved surface template to check the curved surface wall thickness of the bow casting 1 after core setting to ensure the curved surface wall thickness dimensions;

[0043] S6: According to the streamline structure of the integral cantilever core 2, design and fabricate a formed core iron to ensure the core strength, facilitate the exhaust of the core, and prevent the core from being damaged during flask turnover;

[0044] S7: By calculating the weight of the integral cantilever core 2 and cooperating with the setting of core support hard points and columns, effectively prevent the integral cantilever core 2 from floating due to excessive buoyancy, resulting in defective products and unqualified products due to uneven wall thickness;

[0045] S8: Design and fabricate a formed general-purpose sand flask to improve the strength of the back flask and prevent the upper flask from deforming due to buoyancy;

[0046] S9: Track the on-site pouring production, strengthen the process control, and ensure the quality and dimensions of the sand mold;

[0047] S10: After finishing and knocking out the flask, use a total station to mark the bow casting 1 of the first knocked-out flask to determine the casting deformation situation, correct the core and the sand flask, and then adjust the casting process parameters to meet the structural requirements of the bow casting 1;

[0048] S11: According to the flaw detection requirements, inspect the first-piece bow casting 1 to confirm whether there are defects inside the sand box. If there are internal defects, repair the internal defects of the sand box in a timely manner.

[0049] Furthermore, in step S1, the three-dimensional model of the bow casting 1 is a thin-walled special-shaped structure. The thin-walled dimension is 25 - 50 mm, and the special-shaped structure is a mixed structure of L-shaped + arc-shaped.

[0050] Furthermore, in step S3, the process grinding and correction amount for the thin-walled structure is 3 - 5 mm.

[0051] Furthermore, in step S3, the process grinding and correction amount for the non-machined surface is 5 - 15 mm.

[0052] Furthermore, in step S4, the integral cantilever core 2 has only a single-sided core head, and the other side has no core head and is suspended.

[0053] Furthermore, in step S4, the positioning core head structure 3 has a right angle on one side and a slightly triangular shape on the other side.

[0054] Furthermore, in step S7, the core support hard point struts are arranged between the integral cantilever core 2 and the top of the sand box to prevent core lifting and avoid uneven wall thickness of the thin wall.

[0055] Furthermore, in step S6, the formed core iron is arranged inside the integral cantilever core 2 to improve the strength of the core.

[0056] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and its concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A casting process method for a marine bow casting, characterized in that, The described casting process method includes the following: S1: Generate a three-dimensional solid structure diagram of the bow casting using 3D software, and simultaneously conduct a structural profile analysis of the shapes of its various parts; S2: According to the structural characteristics of the bow casting, through casting software simulation, conduct a casting process plan simulation, simulating filling, solidification, and stress deformation; S3: Set the casting process shrinkage rates for different parts, with a stretch of 10‰ - 12‰ at the open ribs and a stretch of 18‰ - 20‰ for the rest; set different process grinding and correction amounts; S4: Adopt a process plan of a cantilever core + positioning core head, manufacture the integral cantilever sand core according to the casting process design; based on the three-dimensional solid structure characteristics of the bow casting generated by the software, calculate the core head counterweight and stabilize the core setting; the core head of the integral cantilever sand core adopts a positioning core head structure to ensure the accuracy of core setting during the mold closing process and the control of the mold closing dimensions; S5: Manufacture a split full-scale wooden pattern according to the integral cantilever sand core and positioning core head structure, and assist in checking the wall thickness of the casting surface after core setting using a curved surface template; S6: Design and manufacture a formed core iron according to the streamline structure of the integral cantilever sand core; S7: Calculate the weight of the integral cantilever sand core and cooperate to set the core support hard point struts; S8: Design and manufacture a formed general-purpose sand box; S9: Track the on-site casting production and strengthen process control; S10: After finishing and knocking out the mold, use a total station to mark the bow casting of the first knocked-out mold to determine the casting deformation situation, correct the sand core and sand box, and then adjust the casting process parameters to meet the structural requirements of the bow casting; S11: According to the flaw detection requirements, detect the first bow casting, confirm whether there are defects inside the sand box, and if there are internal defects, repair the internal defects of the sand box in a timely manner.

2. The casting process method of a marine bow casting according to claim 1, characterized in that In the step S1, the three-dimensional model of the bow casting is a thin-walled special-shaped structure, the thin-walled dimension is 25 - 50 mm, and the special-shaped structure is a mixed structure of L-shaped + arc-shaped.

3. The casting process method of a marine bow casting according to claim 1, characterized in that, In the step S3, the process grinding and correction amount for the thin-walled structure is 3 - 5 mm.

4. The casting process method of a marine bow casting according to claim 1, characterized in that, In the step S3, the process grinding and correction amount for the non-machined surface is 5 - 15 mm.

5. The casting process method of a marine bow casting according to claim 1, characterized in that, In the step S4, the integral cantilever sand core has a positioning core head at one end and is suspended without a core head at the other end.

6. The casting process method of a marine bow casting according to claim 1, characterized in that, In the step S4, the positioning core head structure is a single-sided right angle.

7. The foundry process method of a marine bow casting according to claim 1, characterized in that, In the step S7, the core support hard point struts are set between the integral cantilever sand core and the top of the sand box.

8. The casting process method of a marine bow casting according to claim 1, characterized in that, In the step S6, the formed core iron is set inside the integral cantilever sand core.

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