A modular casting method for railway freight car hook body

Abstract

The present invention relates to a modular casting method for railway freight car hook bodies, which solves the problems existing in traditional casting. 1. Design modular and split casting processes for all types of hook bodies; 2. Design modular core box processes for different types of hook bodies and similar structural hook head parts; 3. Design relevant dimensional structures and process parameters of the pouring system, riser system, and quenching materials; 4. Manufacture modular and split upper / lower metal models; 5. Manufacture the upper / lower metal models in split parts; 6. Manufacture the upper / lower metal model base plates; 7. Manufacture modular core boxes for different types of hook bodies and similar structural hook head parts; 8. Place pre-embedded ear hole cores at the ear hole fixing parts; 9. When placing the hook body core in the lower sand mold, place "I-shaped" steel molding core supports at the upper / lower fixed positions, and place self-made vanishing type molding core supports on the left / right sides; 10. Combine sand molds; 11. Cast. The present invention can meet customers' demands for personalized, short-term, and low-cost hook body products.

Description

Technical Field

[0001] The present invention relates to a modular casting method for a railway freight car hook body Background Art

[0002] The coupler and buffer assembly primarily consists of the coupler body, coupler tongue, buffer, coupler tail frame, and coupling plate. The coupler body is a crucial component of the coupler and buffer assembly. During operation, adjacent railway freight cars are connected via the coupler, and the coupler body bears various loads, including traction and impact, from the locomotive, car body, and track.

[0003] Hook bodies are currently primarily produced using traditional casting techniques. The main process involves designing a dedicated, all-in-one casting process for all types of hook bodies, customizing a dedicated, all-in-one metal mold, preparing the sand box, upper and lower mold plates, and molding sand, placing the sand box on the upper and lower mold plates, adding sand, and compacting it on a vibrating table. Once the surface is dry, the molds are flipped over and removed to obtain the outer contours of the hook body in the upper and lower sand molds. Cores are then inserted and the inner cores are accurately placed in the lower sand mold. The upper and lower molds are then combined, poured, and sanded out to produce the hook casting. The hook body is then subjected to riser removal, flashing, heat treatment, cleaning, and machining to meet the requirements of relevant railway freight car standards.

[0004] The above-mentioned traditional casting process mode for all types of hook bodies is mainly designed to adopt an "integrated" special casting process, so as to customize and manufacture "integrated" special metal models for all types of hook bodies. This traditional design mode results in the number of "integrated" special metal models for all types of hook bodies reaching more than 100 sets, which makes the number of hook body metal models too large, thus occupying too much "golden" production space, increasing the difficulty of managing the hook body metal models, and prompting prominent safety hazards in logistics transportation and online lifting of metal models.

[0005] Furthermore, the specialized metal molds for all types of hooks are produced on an automated production line for molding with ester-hardened sodium silicate sand. Due to the large number of hook types being produced simultaneously, the selected process parameters vary, resulting in varying core sizes and structures. The numerous cores designed into the inner cavity of the hook often lead to misplaced cores during the core-setting process, impacting quality control for all types of hooks.

[0006] In order to ensure the strength and wear resistance of the upper / lower models of all types of hooks, metal materials are currently commonly used to make special models and templates. This is difficult to process and has a long preparation cycle. For small batches or trial production of newly developed products, the production cost of casting tooling for all types of hooks is directly increased, making the production cycle of all types of hooks longer, making it difficult to meet the requirements of short-term delivery to customers. Summary of the Invention

[0007] The present invention provides a modular casting method for a railway freight car hook body, which solves the problems of low actual production efficiency, high casting cost, potential safety hazards, long production cycle, etc. existing in traditional casting.

[0008] The present invention is achieved by the following technical solutions:

[0009] A modular casting method for a railway freight car hook body comprises the following steps:

[0010] 1. Design modular and split casting processes for all types of hooks. That is, define a parting line between the hook head model and the hook body model at the required design size. Use the parting line as the boundary to manufacture split and detachable models. Develop casting process files that are compatible with all types of modular hooks.

[0011] 2. Design a modular core box process for different types of hook bodies and similar structural hook heads. Combined with the structure and size of the model base plate, focus on designing the relevant cores and core heads of different types of hook bodies and similar structural hook heads into a modular unified size structure. According to customer needs, the relevant cores can be directly and quickly replaced modularly during model production. The modular core box size and structure that meets on-site production needs are designed to be fixed, stable, and long-lasting.

[0012] 3. Based on the modular and split metal models of all types of hooks, design the relevant dimensional structures and process parameters of the pouring system, riser system, and chilling materials, and ultimately determine the casting process diagrams that are compatible with all types of hook modularization and can be used in on-site production;

[0013] 4. According to the specific requirements of the casting process drawings of all types of hook bodies, modular and split upper / lower metal models are manufactured. The upper / lower metal models are fixed to the model base plate. Insulation risers, chilling materials, embedded cores, etc. are placed on the upper / lower metal models. After the box is completed, the sand box is filled with mixed ester-hardened water glass molding sand. It is dried in a surface drying furnace. After the molding sand is hardened, the upper / lower sand molds are automatically removed from the metal model by an automatic turning machine. Different specifications of meltable internal chilling materials are inserted at the positions required by the casting process drawings. The relevant cores are placed in the lower sand mold. The upper / lower sand molds are then smoothly combined to form a combined sand mold, and the casting is transferred to the pouring line for pouring.

[0014] 5. According to the requirements of the modular casting process drawing of all types of hook bodies, the upper / lower metal models are manufactured separately, and the pouring system model is manufactured independently. The upper / lower metal models and the pouring system model are matched with the upper surface of the model base plate and fixed;

[0015] 6. Manufacture the upper / lower metal model base plates, including the positioning and matching structure for the upper / lower flask. The positioning and matching structure plays a concentric role with the upper / lower flask. The positioning and matching structure is made with a round pin at one end of the upper / lower metal model base plates for positioning and a square pin at the other end for orientation. The round / square pin and the round / square pin hole of the upper / lower flask are concentrically matched to complete accurate fitting of the flask;

[0016] 7. Modular core boxes are manufactured for hook bodies of different models and hook heads of similar structures. The core heads of the hook heads are modular and of uniform size. After the cores are made, the corresponding cores can be replaced directly and quickly during production to form various types of hook bodies required by customers.

[0017] 8. Before the upper / lower metal model base plates and the sand box are put into the box, to ensure the coaxiality and dimensional accuracy of the ear holes in the non-machining key parts of the hook body, pre-embedded ear hole cores are placed in the fixed parts of the ear holes; to ensure the verticality and dimensional accuracy of the push hole in the non-machining key parts of the hook body, pre-embedded iron hole cores are placed in the fixed parts of the push hole. The pre-embedded cores are made of coated sand with high strength, good disintegration and low gas generation.

[0018] 9. When placing the hook body core in the lower sand mold, place an "I-shaped" steel core support at the upper / lower fixed position, and place a self-made lost-type core support on the left / right side;

[0019] 10. Assemble the sand mold and fix it with box clips at the four outer inclined blocks of the sand box to prevent the box from expanding. Place it stably on the pouring platform according to the pouring sequence.

[0020] 11. Pouring.

[0021] The present invention improves the actual production efficiency of all types of hook bodies, facilitates the quality control of the production process of all types of hook bodies, reduces the manufacturing cost of all types of hook body models, eliminates operational safety hazards, shortens the small-batch trial production cycle of newly developed, newly designed, and newly improved hook body products, and meets customers' demands for personalized, short-time, quality-optimized, and low-cost hook body products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flow chart for implementing a modular casting method for a railway freight car hook body;

[0023] Figure 2-1 This is a schematic diagram of the main viewing direction of the modular casting method design of the present invention;

[0024] Figure 2-2 It is a schematic diagram of a top view of a modular casting method design according to the present invention;

[0025] Figure 2-3 2. It is a schematic diagram of the modular casting method design according to the present invention when viewed from above;

[0026] Figure 3-1 This is a schematic diagram of the arrangement of the upper model on the model base plate for implementing the present invention;

[0027] Figure 3-2 This is a schematic diagram of the arrangement of the model on the model base plate for implementing the present invention;

[0028] Figure 4-1 It is a three-dimensional schematic diagram of the uniform size and shape of the integral core of the hook head similar structure of the present invention;

[0029] Figure 4-2 It is a three-dimensional schematic diagram of the uniform size and shape of the core on the hole of the hook head similar structure implemented in the present invention;

[0030] Figure 4-3 It is a three-dimensional schematic diagram of the embodiment of the present invention, wherein the similar structure of the hook head is reduced to uniform size and shape of the lower core of the hole;

[0031] Figure 5 It is a schematic diagram of the upper / lower sand mold placed in the sand core combined sand mold.

[0032] Legend:

[0033] 1. Hook head model; 2. Hook body model; 3. Upper model; 4. Lower model; 5. Model base; 6. Integral core; 7. Lightening hole upper core; 8. Lightening hole lower core; 9. Upper ear hole core; 10. Lower ear hole core; 11. Push hole core; 12. Hook body core; 13. Molding internal chilling material; 14. Special chilling sand; 15. Exothermic riser sleeve; 16. Casting system model; 17. Molding vanishing core support; 18. Box assembly DETAILED DESCRIPTION

[0034] Example 1

[0035] Implementing the inventive method comprises the following steps:

[0036] 1-1, design modular and split casting process for all types of hooks.

[0037] This case is based on the actual operation of the green, renewable ester-hardened water glass sand automated production line, and guided by the modular concept, to design a modular and split casting process for all types of hooks. Figure 2-1 to Figure 2-3 At 50mm from the hook neck, a modular parting line is designed between Model 1 for the hook head and Model 2 for the hook body. This is where the outer mold and core forming the hook head and the outer mold and core forming the hook body meet. The position of this parting line can be freely adjusted based on the actual size and structure of the hook body.

[0038] The above-mentioned modular and split casting process for all kinds of hook bodies can realize hook bodies of various structures or similar structures. The same model base plate 5 circulating on the ester-hardened water glass sand automated production line is used to modularly replace, splice and fix the hook head model 1 and the hook body model 2, thereby realizing fast and flexible online production of all kinds of hook bodies according to customer needs.

[0039] The hook body core 12 and the lower sand mold have relatively small core heads. To prevent the hook body core 12 from becoming unstable and causing surface defects such as product concavity due to hard contact with other rigid core support materials, two self-made expendable die core supports 17 are used on each side of the hook body core 12 for stability. These expendable die core supports 17 are made of expandable semi-rigid polystyrene and are designed to be 5mm thicker than the wall thickness of the hook body, providing an interference fit. The size and quantity of these expendable die core supports 17 can be adjusted according to actual needs.

[0040] 1-2. Design a modular core box process for different types of hook bodies and similar structure hook heads.

[0041] Figure 2-1 to Figure 2-3 There are many similar structural parts in the hook heads of different types of hook bodies. According to the characteristics of this type of hook body, the design adopts a modular core box process to classify and sort out the hook bodies with different local structures, and the hook head core heads with different sizes and structures of fixed parts are designed according to unified size and structure, so as to realize modular individual fast and flexible replacement of cores and produce different types of hook bodies.

[0042] The modular individual quick and flexible replacement of cores is achieved by mainly designing the core heads of the integral core 6 of the important hook head part, the lightening hole upper core 7, and the lightening hole lower core 8 into uniform required sizes and structures.

[0043] The above modularization realizes individual rapid and flexible replacement of cores in more than three aspects. Other cores can also be modularized and improved to meet the requirements of unified size and structure according to the specific size and structure of the hook body model.

[0044] 1-3. Design the relevant dimensional structure and process parameters of the pouring system, riser system and chilling material.

[0045] Figure 2-1 to Figure 2-3 The gating system model 16 is designed as an independent model tooling, which does not affect the modular replacement, splicing, and fixing of the hook head model 1 and the hook body model 2. The number, size, and location of the gating system model 16 can be selected according to the actual size and structure requirements of all types of hooks. The process parameters can be determined by referring to the General Casting Process Guide for Sand Mold Steel Castings.

[0046] According to the general process requirements of all types of hook bodies, the molding internal chilling material 13, special chilling sand 14 and exothermic riser sleeve 15 are placed in the positions. The quantity, size and position of the above three raw and auxiliary materials can be selected according to the actual requirements of the size and structure of all types of hook bodies. The process parameters can be determined by referring to the general casting process guidance book for sand mold steel castings.

[0047] 1-4, manufacture and install the upper / lower metal models separately.

[0048] The upper and lower molds 3 and 4, which form the hook head mold 1, and the upper and lower molds 3 and 4, which form the hook body mold 2, are independently manufactured using a modular, split casting process for all types of hook bodies. The molds are made of wear-resistant cast iron. The wear-resistant materials used for the molds are not limited to the aforementioned reference materials.

[0049] Figure 3-1 and Figure 3-2 According to the modular and split casting process of all types of hook bodies, the upper model 3 and the lower model 4 constituting the hook head model 1, the upper model 3 and the lower model 4 constituting the hook body model 2, and the pouring system model 16 are respectively installed and fixed on the model base plate 5.

[0050] Model base plate 5 weighs 2.1 tons and is made of high-strength wear-resistant steel. It circulates in a closed loop on an automated production line of ester-hardened water glass sand. Model base plate 5 is the key carrier for implementing modular and split casting processes for all types of hooks.

[0051] 1-5, manufacture modular core boxes with different hook body types and similar hook head structures

[0052] Figure 4-1 and Figure 4-3 The hook body is manufactured using a modular, split casting process for all hook types. The six-core integral core for the hook head and the twelve-core core for the hook body are independently manufactured. Both the six-core integral core and the twelve-core core for the hook body utilize a modular, uniformly sized structure. The core box is constructed of wear-resistant cast aluminum. The wear-resistant materials used for the core box are not limited to those listed above.

[0053] The hook head integral core 6 is a crucial component in forming the precise structure of the hook head casting. The coaxiality of the upper and lower lug holes must be high, so the upper and lower lug hole cores 9 and 10 need to be pre-embedded within the hook head integral core 6. The push hole is crucial for the automatic three-mode operation of the coupler, requiring high dimensional structure, structure, and surface finish. Therefore, the push hole core 11 needs to be pre-embedded within the hook head integral core 6. Special chilling sand 14 is pre-embedded within the hot zone of the hook head integral core 6. The placement and amount of sand required are determined based on actual needs.

[0054] The upper and lower ear hole cores 9 and 10 have different core head structures, making it easier to distinguish between the cores. The cores are made of low-gassing coated sand to ensure a smooth surface finish for the upper and lower ear holes. The core head structure and core material are not limited to those described above.

[0055] The material of the iron hole core 11 is made of low-gas coated sand to ensure the smooth surface of the upper / lower ear holes. The core head structure and the core material are not limited to the above.

[0056] The upper and lower cores (7 and 8) of the hook head's lightening hole are independently manufactured using a modular, split-part casting process for all hook types. The upper and lower cores utilize a modular, uniformly sized design. The upper core (7) features two positioning grooves, while the lower core (8) features two positioning bosses. The upper and lower cores' positioning grooves mate with the lower core's positioning bosses. Both the upper and lower core boxes are constructed from wear-resistant cast aluminum. The wear-resistant materials used for the core boxes are not limited to those listed above.

[0057] Other cores can also be designed with modular core head size and structure according to the actual needs of all types of hook bodies.

[0058] 1-6, process-based production of all types of hooks on demand.

[0059] Figure 3-1 and Figure 3-2 , install and fix the modular, split all-type hook upper model 3, lower model 4, and pouring system model 16 on the model base plate 5 according to the process drawing. Figure 2-1 to Figure 2-3 After the mold base plate 5 is transferred to the production preparation process on the ester-hardened water glass yarn automated production line, the heating riser sleeve 15 and special chilled sand 14 are placed according to the process requirements. Then, a sand box is automatically put on the mold base plate 5 using a box-putting machine, sand is filled with sand by a sand mixer, and vibrated and compacted on a vibrating table. The mold is hardened in a first-time surface drying furnace. The mold is then removed by a flip mold-pulling machine. After cleaning the loose sand in the mold cavity, an alcohol-based paint is evenly applied. After drying, the inner chilled material 13 is placed in the mold. After the second-time surface drying furnace hardening, the sand mold is refined. Figure 4-1 to Figure 4-3 , put the modular integral core 6, the lightening hole upper core 7, the lightening hole lower core 8, the hook body core 12 and other modular cores into the lower sand mold, and put the molding disappearing core support 17 on both sides of the split hook body core 12 to stabilize the core. After blowing away the floating sand, use the box closing machine to automatically close the box. Figure 5 , after closing the flask, the flask is fixed in position

[0060] 1. Modular and split casting process design for all types of hooks. Guided by the modular concept, a modular and split casting process is designed for all types of hooks. A modular parting line is designed at 50 mm from the hook neck for the hook head part model 1 and the hook body part model 2. That is, the outer mold and core forming the hook head and the outer mold and core forming the hook body are spliced and combined at the parting line. The position of the parting line can be freely adjusted according to the actual size and structure of the hook body.

[0061] 2. Design of modular core heads with similar structures for all types of hooks. Different types of hooks have many similar structural parts in the hook heads. In view of the characteristics of this type of hook, a modular core box process is designed to classify and sort out hooks with different local structures. The core heads of the hook heads with different sizes and structures of fixed parts are designed with unified size and structure, realizing modular individual fast and flexible core replacement to produce different types of hooks. The core heads of the integral core 6, the lightening hole upper core 7, and the lightening hole lower core 8 of the important hook head parts are designed with unified size and structure. Modular cores are not limited to the above three items. Other cores can also be modularized to improve the unified size and structure requirements according to the specific size and structure of the hook model.

[0062] 3. Utilize a custom-made expendable core support. The hook body core 12 and the lower sand mold have relatively small core heads. To prevent the hook body core 12 from becoming unstable and causing surface defects such as product concavity due to hard contact with other rigid core support materials, custom-made expendable core supports 17 are used on both sides of the hook body core 12 for stability. Two expendable core supports 17 are used on each side. These expendable core supports 17 are made of expandable semi-rigid polystyrene and are designed to be 5mm thicker than the wall thickness of the hook body, ensuring an interference fit. The size and quantity of these expendable core supports 17 can be adjusted based on actual needs.

[0063] The present invention has the following beneficial effects:

[0064] 1. Improve the actual production efficiency of all types of hooks. Improve the production efficiency of hook products from multiple dimensions, such as facilitating process quality control, shortening model and core box manufacturing time, and simplifying model management.

[0065] 2. Easier quality control during the production of all types of hooks. There are many types of hooks, each designed according to a specific process for prototyping cores. The core heads vary in size and structure, making it easy for cores to be mixed up when placed in the mold, significantly impacting hook product quality. The modular core design allows for easy operation and accurate identification of the core being used.

[0066] 3. Reduce the manufacturing cost of all types of hook body models. Modular and split manufacturing of all types of hook body models. Models with different structures in the hook head or hook body can be directly manufactured for the hook head or hook body, reducing the manufacturing cost of all types of hook body models.

[0067] 4. Eliminate operational safety hazards. The model base weighs 2.1 tons and is produced in a closed cycle in the automated production of ester-hardened sodium silicate sand. If the "integrated" hook model is fixed to the model base according to the original traditional manufacturing method, manual lifting or transportation of the entire type of hook model and model base would pose a significant safety risk.

[0068] 5. Shorten the production cycle for small-batch trial production of newly developed, newly designed, and newly improved hook products. Modular and split manufacturing of all types of hook models and core boxes is possible. Models with different hook head or body structures can be directly manufactured for the hook head or body, shortening the manufacturing time for all types of hook models. For core boxes with different local structures of the hook head or body, modular core boxes can be directly manufactured, shortening the manufacturing time for all types of hook models.

[0069] 6. Timely meet customers' demands for personalized, short-time, quality-optimized and low-price hook products, and enhance customers' product service experience and product quality satisfaction.

Claims

1. A modular casting method for a railway freight car hook body, characterized by: The following steps are involved: 1) Design modular and split casting processes for all types of hooks. That is, define a parting line between the hook head model and the hook body model at the required design size. Use the parting line as the boundary to manufacture split and detachable models. Develop casting process documents that are compatible with all types of modular hooks. 2) Design a modular core box process for different hook body models and similar hook head structures. Combined with the model base plate structure and size, focus on designing the relevant cores and heads of different hook body models and similar hook head structures into a modular unified size structure. According to customer needs, the relevant cores can be directly and quickly replaced modularly during model production. The modular core box size and structure that meets on-site production needs are designed to be fixed, stable, and long-lasting. 3) Based on modular and split metal models of all hook types, design the relevant dimensional structures and process parameters of the pouring system, riser system, and chilling materials, and ultimately determine a casting process diagram that is compatible with all hook types and can be used in on-site production; 4) According to the specific requirements of the casting process drawings for all types of hook bodies, modular, split upper and lower metal models are manufactured. The upper and lower metal models are fixed to the model base plate. Insulation risers, chilling materials, and pre-embedded cores are placed in the upper and lower metal models. After the box is completed, the sand box is filled with mixed ester-hardened water glass molding sand. After the molding sand is dried in a surface drying furnace and hardened, the upper and lower sand molds are automatically removed from the metal model by an automatic turnover machine. Different specifications of meltable internal chilling materials are inserted at the positions required by the casting process drawings. The relevant cores are placed in the lower sand mold. The upper and lower sand molds are then smoothly combined to form a combined sand mold, and the casting is transferred to the pouring line for pouring; 5) According to the requirements of the modular casting process drawing of all types of hook bodies, the upper / lower metal models are manufactured separately, and the pouring system model is manufactured independently. The upper / lower metal models and the pouring system model are matched with the upper surface of the model base plate and fixed; 6) Manufacturing the upper / lower metal model base plate, including manufacturing the positioning and matching structure for the upper / lower flask. The positioning and matching structure plays a concentric role with the upper / lower flask. The positioning and matching structure is made into a round pin at one end of the upper / lower metal model base plate for positioning and a square pin at the other end for orientation. The round / square pin and the round / square pin hole of the upper / lower flask are concentrically matched to complete the accurate fitting of the flask; 7) Modular core boxes are manufactured for different types of hook bodies and similar hook heads. The core heads of the hook heads are modular and have a unified size structure. After the cores are made, the corresponding cores can be quickly replaced during production to form various types of hook bodies required by customers. 8) Before the upper / lower metal model base plates and the sand box are put into the box, to ensure the coaxiality and dimensional accuracy of the ear holes in the non-machining key parts of the hook body, pre-embedded ear hole cores are placed in the fixed parts of the ear holes; to ensure the verticality and dimensional accuracy of the push hole in the non-machining key parts of the hook body, pre-embedded iron hole cores are placed in the fixed parts of the push hole. The pre-embedded cores are made of coated sand with high strength, good disintegration and low gas generation; 9) When placing the hook body core in the lower sand mold, place an "I-shaped" steel core support at the upper / lower fixed positions, and place a self-made lost-type core support on the left / right sides; 10) Assemble the sand mold, fix it with box clips at the four outer inclined blocks of the sand box to prevent the box from expanding, and place it stably on the pouring platform according to the pouring sequence; 11) Pouring.

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