Forming method of inner cylinder casting

Abstract

The invention relates to an inner cylinder casting forming method which comprises the steps that a casting sand core is divided into at least four layers for independent 3D printing, the first layer is a bed mould core (110), the second layer is a vertical pipe outer contour core (120), the third layer is an inner cylinder outer contour core (130), and the fourth layer is a cover core (140), so that an outer contour structure of a casting is formed; for an inner cavity structure of a casting, two vertical pipe cores (210) and a tire hanging core (220) are designed and printed, the tire hanging core (220) is further split into a tire hanging core main body (221) and four cores (222), and the four cores (222) are areas with high sand burning risk on the tire hanging core (220) and are formed by printing chromium ore materials. According to the scheme, the application range of the sand core 3D printing technology in the casting field can be expanded, and particularly the effective application of the sand core 3D printing technology on large-size and complex-structure products such as inner cylinders can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of casting methods, in particular to a molding method of an inner cylinder casting. Background Art

[0002] In today's manufacturing industry, 3D printing technology has rapidly risen with its subversive attitude and deeply penetrated into various industrial segments, showing unprecedented application potential. Especially in the casting process, the emergence of sand core 3D printing technology marks a major technological innovation in the casting industry. This technology perfectly combines the rapid prototyping advantages of 3D printing - high efficiency, flexibility and precision, and can be directly driven by digital models to achieve one-time accurate printing of complex internal structures and fine contours, completely subverting the cumbersome process of traditional sand core casting that relies on manual mold making.

[0003] In the traditional sand core casting process, the process from design to physical model production often takes a long time and is costly, and the accuracy and flexibility of the model are limited by the limitations of manual operation. The introduction of sand core 3D printing technology has greatly simplified this process, not only eliminating the step of designing physical models, reducing material waste and manufacturing costs, but also significantly shortening the cycle from design to finished product. This transformation has shown great value in accelerating product development and improving market responsiveness.

[0004] However, although sand core 3D printing technology has achieved remarkable results in the manufacturing of miniaturized and lightweight products, especially for parts made of low alloy steel or carbon steel, its application breadth and depth still need to be further expanded. When facing large-sized and highly complex products such as inner cylinders, the traditional solid sample molding method still occupies a dominant position, but the high cost, long cycle, difficulty in demolding, and high defect rate of semi-finished products in mold design and production have become bottlenecks restricting production efficiency and product quality. Especially in time-sensitive projects, the long mold production cycle often leads to delivery delays, affecting customer satisfaction and the market competitiveness of enterprises. Therefore, how to break through the limitations of the current sand core 3D printing technology in processing large-sized and complex structure castings, reduce production costs, and improve manufacturing efficiency and finished product quality has become a key technical problem that needs to be solved urgently. This challenge is not only related to the deeper application exploration of 3D printing technology in the casting field, but also directly related to the process of the entire manufacturing industry's transformation to intelligence and green. Summary of the invention

[0005] Based on this, it is necessary to provide a molding method for inner cylinder castings to address the problem of how to expand the application scope of sand core 3D printing technology in the casting field, especially the effective application of large-size and complex structure products such as inner cylinders.

[0006] In order to solve the above problems, the present invention adopts the following technical solutions:

[0007] The embodiment of the present invention discloses a method for forming an inner cylinder casting, comprising:

[0008] The casting sand core is split into at least four layers for independent 3D printing, the first layer is the tire plate core, the second layer is the vertical tube outer contour core, the third layer is the inner cylinder outer contour core, and the fourth layer is the cover core, so as to form the outer contour structure of the casting;

[0009] For the inner cavity structure of the casting, two vertical tube cores and one hanging tire core were designed and printed. The hanging tire core was further divided into a hanging tire core body and four cores. These four cores are areas on the hanging tire core with a higher risk of sand sticking, and they were printed using chromium ore sand material.

[0010] In one embodiment, in the vertical tube sub-core area, a straight tie rod is used as a supplement, and a heat riser is used in combination for shrinkage compensation.

[0011] In one embodiment, a heat-generating riser is selected that is at least 2-3 levels smaller than a common heat-insulating riser with the same modulus, and the distance between the heat-generating riser heat-insulating brick and the casting is increased.

[0012] In one of the embodiments, for a sand core having a special structure and a relatively weak structure in a local area, reinforcing ribs are designed and arranged to enhance the structural strength of the area; before the sand core completes its function as a casting forming mold, the above-mentioned reinforcing ribs are removed and the removed parts are subjected to conformal grinding.

[0013] In one embodiment, the tire hanging core body and the four cores are combined in an inlay manner.

[0014] In one embodiment, a limiting boss is provided on the main body of the tire hanging core, and the core is located on the main body of the tire hanging core and is limitedly matched with the limiting boss.

[0015] In one embodiment, the tire hanging core body and the four cores are combined by a connecting tool.

[0016] In one of the embodiments, the connecting tool includes a first face core tool, a second face core tool and a connecting piece. Countersunk grooves are respectively opened on two opposite planes of the hanging tire core. The first face core tool and the second face core tool are respectively in the countersunk grooves, and one end of the connecting piece is connected to the first face core tool, and the other end of the connecting piece is connected to the second face core tool on the other side, so as to clamp the hanging tire core body and the four cores between the first face core tool and the second face core tool.

[0017] In one embodiment, the countersunk groove is provided on the surface of the core head of the tire hanging core.

[0018] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0019] In the molding method of the inner cylinder casting disclosed in the embodiment of the present invention, the rapid molding of the sand core is achieved through 3D printing technology, which greatly shortens the production cycle of the sand core and improves the casting efficiency. At the same time, it reduces the manpower and material input in the traditional production process, and reduces the cost of mold production and sand core production. Furthermore, the embodiment of the present invention ensures the accuracy and consistency of the sand core through precise 3D printing control and reasonable sand core splitting design, thereby improving the dimensional accuracy and surface quality of the casting. The use of chromium ore sand material to print the high-risk areas in the inner cavity core effectively reduces the risk of sand sticking to the casting during the pouring process. In summary, the molding method of the inner cylinder casting provided by the present invention expands the application scope of the sand core 3D printing technology in the casting field, especially the effective application in large-size and complex structure products such as inner cylinders. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of an outer contour sand core disclosed in an embodiment of the present invention;

[0021] Figure 2 It is a schematic structural diagram of a sand core with an inner cavity structure disclosed in an embodiment of the present invention;

[0022] Figure 3 for Figure 2 Exploded diagram of

[0023] Figure 4 It is a schematic diagram of the structure of the connecting tool disclosed in an embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 110- tire plate core, 120- vertical tube outer contour core, 130- inner cylinder outer contour core, 140- cover core, 210- vertical tube core, 220- hanging tire core, 221- hanging tire core body, 222- core, 223- countersink groove, 300- connecting tooling, 310- first face core tooling, 320- second face core tooling, 330- connecting piece. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0027] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a centered element at the same time. The terms "vertical", "horizontal", "left", "right", "top", "bottom", "bottom end", "top end" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] like Figure 1-Figure 4 As shown, the embodiment of the present invention discloses a molding method of an inner cylinder casting, and the disclosed molding method of the inner cylinder casting specifically includes:

[0030] Sand core split design: According to the structural characteristics of the casting, the sand core is split into at least four layers for independent 3D printing. Specifically, the first layer is the tire plate core 110, which is used to form the basic structure of the bottom of the casting; the second layer is the vertical tube outer contour core 120, which prints the outer contour of the vertical tube; the third layer is the inner cylinder outer contour core 130, which prints the outer contour of the inner cylinder; the fourth layer is the cover core 140, which covers the top of the casting and together with the first three layers of sand cores constitutes the outer contour structure of the casting. This layered design is not only convenient for printing, but also effectively avoids deformation and warping during the printing process.

[0031] Printing of inner cavity structure: For the inner cavity structure of the casting, two vertical tube cores 210 and a hanging tire core 220 are designed and printed. The hanging tire core 220 is relatively complex and needs to be further divided into a hanging tire core body 221 and four cores 222. These four cores 222 correspond to the areas on the hanging tire core where the risk of sand sticking is higher, and chromium ore sand material is used for 3D printing. With its excellent anti-sand sticking performance, chromium ore sand can effectively reduce the risk of sand sticking in these areas and improve the surface quality of castings. In one embodiment, in the area of ​​the vertical tube core 210, a straight tie rod is used as a supplement, and a heating riser is used in combination for shrinkage compensation.

[0032] It can be seen from the above content that in the molding method of the inner cylinder casting disclosed in the embodiment of the present invention, the rapid molding of the sand core is achieved through 3D printing technology, which greatly shortens the production cycle of the sand core and improves the casting efficiency. At the same time, it reduces the manpower and material input in the traditional production process, and reduces the cost of mold production and sand core production. Furthermore, the embodiment of the present invention ensures the accuracy and consistency of the sand core through precise 3D printing control and reasonable sand core splitting design, thereby improving the dimensional accuracy and surface quality of the casting. The use of chromium ore sand material to print the high-risk areas in the inner cavity core effectively reduces the risk of sand sticking to the casting during the pouring process. In summary, the molding method of the inner cylinder casting provided by the present invention expands the application scope of sand core 3D printing technology in the casting field, especially the effective application in large-size and complex structure products such as inner cylinders.

[0033] Furthermore, a heating riser with a specification at least 2-3 levels smaller than that of an ordinary insulation riser with the same modulus is selected, and the spacing between the heating riser insulation brick and the casting is increased. In this case, by selecting a heating riser and reducing its specifications, combined with an optimized spacing setting, the shrinkage compensation efficiency of the casting is significantly improved, and the incidence of defects such as shrinkage cavities and shrinkage porosity is reduced. Increasing the spacing between the riser insulation brick and the casting effectively reduces the thermal impact of the riser on the casting, and reduces the deformation and cracking of the casting caused by thermal stress. At the same time, the efficient shrinkage compensation capacity of the heating riser enables the quality requirements of the casting to be met while reducing the size of the riser, thereby reducing the consumption of raw materials and the generation of waste, and reducing production costs. Through the combined effect of the above-mentioned optimization measures, the overall quality and reliability of the casting are significantly improved, providing a strong guarantee for the subsequent processing and use of the product.

[0034] In an embodiment of the present invention, for a sand core having a special structure and a relatively weak structure in a local area, reinforcing ribs are designed and arranged to enhance the structural strength of the area; before the sand core completes its function as a casting forming mold, the reinforcing ribs are removed, and the removed parts are subjected to conformal grinding. In this case, by designing and arranging reinforcing ribs and the subsequent removal and grinding, effective reinforcement and repair of the sand core having a special structure and a relatively weak structure in a local area is achieved. This solution not only improves the structural strength and stability of the sand core, but also ensures the high quality and high reliability of the final casting. At the same time, the solution also has the advantages of simple operation and low cost, and is easy to promote and apply in casting production.

[0035] In an optional embodiment, the tire hanging core body 221 and the four cores 222 are combined in an inlay manner. In this case, the tire hanging core body 221 and the four cores 222 are combined in an inlay manner, which significantly improves the accuracy, stability and efficiency of the casting process, reduces production costs and scrap rates, and also provides a strong guarantee for the production of high-quality and high-reliability castings.

[0036] Furthermore, a limiting boss is provided on the main body 221 of the hanging core, and the core 222 is located on the main body 221 of the hanging core and is limitedly matched with the limiting boss. In this case, the limiting match between the limiting boss and the core 222 ensures accurate alignment during the assembly process. This mechanical limiting method is more reliable than the traditional method that relies on manual operation or simple geometric shape matching, and effectively prevents the core from being offset or misaligned during the assembly process, thereby ensuring the accuracy and precision of the casting structure. Secondly, the limiting match enhances the connection strength between the main body 221 of the hanging core and the core 222. During the casting process, the sand core needs to withstand high temperature, high pressure and complex stress, and the close match between the limiting boss and the core can effectively disperse these stresses, prevent the core from falling off or being damaged, and improve the overall stability and durability of the sand core. In addition, the design of the limiting boss also simplifies the assembly process and improves production efficiency. The operator can more easily place the core accurately on the main body of the hanging core and quickly position it through the limiting boss without complex adjustments or additional fixing measures. This not only reduces operation time, but also reduces the possibility of human error.

[0037] Furthermore, the tire core body 221 and the four cores 222 are combined by a connecting fixture 300. In this case, the design of combining the tire core body 221 and the four cores 222 by a connecting fixture 300 not only improves the accuracy and consistency of the casting, but also enhances the stability of the combined structure, simplifies the combination process and improves production efficiency. At the same time, this design also helps to reduce production costs and improve production benefits, providing strong support for the optimization and improvement of the casting process.

[0038] In an optional embodiment, the connecting tool 300 includes a first face core tool 310, a second face core tool 320 and a connecting piece 330, and two opposite planes of the hanging tire core 220 are respectively provided with countersunk grooves 223, the first face core tool 310 and the second face core tool 320 are respectively located in the countersunk grooves 223, and one end of the connecting piece 330 is connected to the first face core tool 310, and the other end of the connecting piece 330 is connected to the second face core tool 320 on the other side, so as to clamp the hanging tire core body 221 and the four cores 222 between the first face core tool 310 and the second face core tool 320. This method not only improves the accuracy and reliability of the casting, but also simplifies the assembly process, improves production efficiency, and reduces production costs.

[0039] Furthermore, the countersunk groove 223 is opened on the surface of the core head of the hanging core 220. In this case, if it is opened on the live surface, a steel plate needs to be placed in the countersunk groove 223. At this time, the steel plate in the countersunk groove 223 will play the role of sand isolation and cold iron, which will change the shrinkage compensation gradient of the casting, so it should be placed away from the live surface during design.

[0040] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for forming an inner cylinder casting, characterized in that: include: The casting sand core is split into at least four layers for independent 3D printing, wherein the first layer is a tire plate core (110), the second layer is a vertical tube outer contour core (120), the third layer is an inner cylinder outer contour core (130), and the fourth layer is a cover core (140), so as to form an outer contour structure of the casting; For the inner cavity structure of the casting, two vertical tube cores (210) and a hanging tire core (220) are designed and printed. The hanging tire core (220) is further divided into a hanging tire core body (221) and four cores (222). The four cores (222) are areas on the hanging tire core (220) with a higher risk of sand sticking, and are printed and formed using chromium ore sand material.

2. The method for forming an inner cylinder casting according to claim 1, characterized in that: In the vertical tube sub-core (210) area, straight tie bars are used as compensation, and heat risers are used in combination for shrinkage compensation.

3. The method for forming an inner cylinder casting according to claim 2, characterized in that: Choose a heating riser that is at least 2-3 grades smaller than the ordinary insulation riser with the same modulus, and increase the distance between the heating riser insulation brick and the casting.

4. The method for forming an inner cylinder casting according to claim 1, characterized in that: For sand cores with special structures and relatively weak structures in local areas, reinforcing ribs are designed and set to enhance the structural strength of the area; before the sand core completes its function as a casting forming mold, the above-mentioned reinforcing ribs are removed and the removed parts are ground according to the shape.

5. The method for forming an inner cylinder casting according to claim 1, characterized in that: The tire hanging core body (221) and the four cores (222) are combined in an inlay manner.

6. The method for forming an inner cylinder casting according to claim 5, characterized in that: A limiting boss is arranged on the tire hanging core body (221), and the core (222) is located on the tire hanging core body (221) and is limitedly matched with the limiting boss.

7. The method for forming an inner cylinder casting according to claim 5, characterized in that: The tire hanging core body (221) and the four cores (222) are combined using a connecting tool (300).

8. The method for forming an inner cylinder casting according to claim 7, characterized in that: The connecting tool (300) comprises a first face core tool (310), a second face core tool (320) and a connecting piece (330). Two opposite planes of the hanging tire core (220) are respectively provided with countersunk grooves (223). The first face core tool (310) and the second face core tool (320) are respectively located in the countersunk grooves (223). One end of the connecting piece (330) is connected to the first face core tool (310), and the other end of the connecting piece (330) is connected to the second face core tool (320) on the other side, so as to clamp the hanging tire core body (221) and the four cores (222) between the first face core tool (310) and the second face core tool (320).

9. The method for forming an inner cylinder casting according to claim 9, characterized in that: The countersunk groove (223) is formed on the surface of the core head of the tire hanging core (220).

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