A process for making a core for a casting head

Abstract

The present application relates to the field of casting riser, especially to a kind of casting heat preservation riser core assembling process method.The present application provides a kind of casting heat preservation riser core assembling process method to solve the problems of displacement of heat preservation riser in prior art, low operation efficiency and the like.The present application solves the problems of displacement of post-positioned heat preservation riser and low waiting efficiency.The displacement prevention riser cover core is organically combined with sand core upper cover core and heat preservation riser to form a whole, effectively solving the problem of riser displacement.Meanwhile, the displacement prevention riser cover core is flexible and adjustable according to the size change of heat preservation riser, and has strong versatility;standard cover cores of various types are designed according to the size of riser, which is convenient for on-site use, and printing is carried out using idle position of printer, effectively saving cost.

Description

Technical Field

[0001] This invention relates to the field of risers for casting, and more particularly to a process for assembling a core of an insulating riser for casting. Background Technology

[0002] Casting 3D printing technology is an advanced manufacturing technology based on the principle of layer-by-layer stacking, using powdered materials such as ceramsite sand and silica sand as molding raw materials, and achieving rapid sand core forming through the spraying of binders. This technology eliminates the need for traditional molds, enabling the efficient manufacture of sand cores with complex internal structures. It effectively solves the prominent bottlenecks of traditional casting in meeting the demands of "complex structures, rapid response, and personalized customization," such as long cycle times, high mold costs, and high process difficulty. It significantly expands the design freedom and manufacturing capabilities of casting processes, and is a key practical carrier for the concepts of intelligent manufacturing and Industry 4.0 in the casting field. Despite the significant advantages of casting 3D printing technology, its industrialization still faces practical challenges such as low sand core yield and high equipment investment and specialized material costs. Continuous process optimization to improve yield and reduce overall costs has become a core issue for promoting the large-scale application of this technology.

[0003] In existing post-processing and core assembly techniques for 3D printed sand cores, after sand core cleaning, impregnation, and drying, the cores are directly assembled on a tray. For some products, an insulating riser needs to be placed after core assembly, and a nylon vent rope is inserted into the vent hole at the top of the riser and tied to the inside to release vents. Then, resin sand is manually filled and compacted along the outer perimeter and top of the riser, and casting can only proceed after it has fully hardened (usually about 2 hours). However, this method has significant drawbacks: on the one hand, the long waiting time required for resin sand hardening severely restricts core assembly efficiency; on the other hand, the quality of the artificially mixed resin sand fluctuates greatly, and insufficient hardening often causes the riser to shift due to the buoyancy and impact of molten iron during casting, leading to shrinkage cavities, porosity, or even scrapping of the casting. Summary of the Invention

[0004] To address the problems of displacement and low operating efficiency of insulating risers in existing technologies, a method for assembling insulating risers for casting is provided. The method for assembling insulating risers for casting includes the following steps: S1: After the sand core assembly is completed, mud strips are laid axially at the bottom groove of the inner wall of the riser cavity to form a closed mud strip ring; S2: Seal the vent of the thermal insulation riser with paper tape, and then put the thermal insulation riser into the riser cavity to make its circumferential gaps evenly distributed; S3: Screw the riser cover core with the vent groove into the riser cavity until the bottom of the riser cover core contacts the top of the insulation riser; S4: An air outlet is provided in the middle of the riser cover core. The loose sand in the air outlet of the riser cover core is cleaned, and the air outlet is sealed with paper tape. S5: Pouring at the water inlet.

[0005] In one embodiment, the riser cap core is circumferentially threaded on its outer side, and the riser cap core is screwed vertically into the riser cavity along the threaded structure at the top.

[0006] In one embodiment, the thread pitch at the top of the riser cavity is 10 mm.

[0007] In one embodiment, the vent groove is arranged radially along the riser cap core, and the vent groove is annular.

[0008] In one embodiment, the cross-sectional dimensions of the air outlet groove are 15mm × 15mm.

[0009] In one embodiment, the riser cap core is 3D printed.

[0010] In one embodiment, the lower part of the riser cover core is provided with a circumferentially arranged vent groove, and after the riser cover core is assembled, the vent of the insulating riser is always located within the range of the vent groove.

[0011] In one embodiment, the mud strip is placed in a pre-set groove at the bottom of the cover core, and the lower part of the groove is 3mm larger than the outer diameter of the insulation riser.

[0012] In one embodiment, the two vents of the riser cap core can serve as assembly grippers.

[0013] In one embodiment, the size of the insulating riser is determined based on the casting modulus.

[0014] The anti-displacement riser cover core described in this invention has the following beneficial effects in solving the problem of displacement of the rear-insulated riser: (1) The anti-displacement riser cap core has a simple structure and is printed using the printer's idle position, resulting in low cost; (2) Eliminating the use of the air vent rope further reduces costs; (3) The operation of the post-insulated riser is simple and the riser is firmly fixed; (4) The entire installation process is continuous, with no additional sand filling, eliminating waiting time and improving efficiency; (5) The anti-displacement riser cover core has a spiral structure. After the insulation riser is installed, it is locked as a whole. During the pouring process, the riser is subjected to the buoyancy of the molten iron. The greater the buoyancy, the more firmly the insulation riser is fixed.

[0015] (6) For larger insulation risers, the size of the anti-displacement riser cover core is increased accordingly to improve its strength and flexibility. Attached Figure Description

[0016] Appendix Figure 1Schematic diagram of riser cavity structure; Appendix Figure 2 : Cross-sectional view of riser cavity structure; Appendix Figure 3 Schematic diagram of riser cap core structure; Appendix Figure 4 : Sectional view of the insulated riser assembly; Appendix Figure 5 : Paper tape assembly diagram; Appendix Figure 6 : Sectional view of riser cap core assembly; Appendix Figure 7 Top view of riser cap assembly; 200-Sand core, 210-Riser, 211-Riser cavity, 212-Threaded structure, 213 Groove, 220-Riser cover core, 221-Air outlet groove, 222-Air outlet, 230-Insulating riser, 231-Clay strip, 232-Paper tape. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] A method for assembling an insulating riser core for casting includes the following steps: S1: After the sand core 200 sets are completed, mud strips 231 are arranged axially at the bottom groove 213 of the inner wall of the riser cavity 211 to form a closed mud strip ring. The mud strip ring can prevent sand and gravel from entering the interior of the heat-insulating riser and causing quality defects such as sand holes and porosity in the casting. S2: After the insulating riser 230 is placed into the riser cavity, the vent of the insulating riser 230 is sealed with paper tape 232. The paper tape is used to prevent sand and gravel from entering the insulating riser and causing quality defects in the casting. The top of the insulating riser 230 is lower than the thread of the riser cavity 211.

[0021] S3: Screw the riser cover core 220 with the vent groove 221 into the riser cavity 211 until the bottom of the riser cover core 220 contacts the top of the insulating riser 230. S4: Several vents 222 are provided in the middle of the riser cover core 220. After cleaning the loose sand in the vents 222 of the riser cover core 220, the vents 222 are sealed with paper tape 232. The paper tape is used to prevent sand and gravel from entering the heat-insulating riser and causing quality defects in the casting. S5: Pouring at the water inlet.

[0022] In a preferred embodiment of the present invention, a threaded structure 212 is provided on the outer circumferential side of the riser cover core 220, and the riser cover core 220 is screwed vertically into the threaded structure 212 at the top of the riser cavity 211; the anti-displacement riser cover core 220 has a spiral structure, and the insulating riser 230 is locked as a whole after installation; during the pouring process, the riser is subjected to the buoyancy of the molten iron, and the greater the buoyancy, the more firmly the insulating riser 230 is fixed. For larger insulating risers 230, the anti-displacement riser cover core 220 is correspondingly enlarged to improve its own strength and flexibility.

[0023] In a preferred embodiment of the present invention, the vent groove 221 is arranged in a ring structure radially along the riser cover core 220; the lower part of the riser cover core 220 is provided with a vent groove 221 arranged around the perimeter. After the riser cover core 220 is assembled, the vent hole of the heat-insulating riser 230 is always located within the range of the vent groove 221, which can effectively prevent the vent hole from being blocked.

[0024] In a preferred embodiment of the present invention, the mud strip 231 is arranged in a pre-set groove 213 at the bottom of the cover core, and the lower part of the groove is 3mm larger than the outer diameter of the heat insulation riser 230.

[0025] The technical solution of the present invention will be further illustrated by taking the 3D printing sand core assembly process of a certain spherical iron part as an example.

[0026] The riser size and location are calculated based on the casting modulus, and the sand core is designed after passing Magma simulation. The riser cavity is designed on the top cover core of the sand core. Taking one insulating riser 230 as an example, the entire design and installation process mainly includes the following steps: (1) Based on the casting module, the size of the insulation riser 230 is determined to be φ120×120mm; (2) A heat-insulating riser cavity 211 is designed on the cover core of the sand core 200. The riser cavity 211 and the upper cover core of the sand core 200 are integrally formed. A groove 213 is designed at the bottom. The lower part of the groove 213 is 3mm larger than the outer diameter of the heat-insulating riser 230. The upper part has a threaded structure 212 with a pitch of 10mm. (3) The riser cap core 220 has a threaded structure 212 on the side and a 15mm×15mm vent groove 221 at the bottom, with two vents 222 in the middle; the vent groove 221 is designed to be around the circumference to ensure that the vent of the insulation riser 230 is always within the range of the vent groove 221, which can effectively prevent the vent from being blocked; the two vents 222 in the middle can also be used as grippers for the riser cap core 220; the riser cap core 220 is 3D printed.

[0027] The specific core assembly and pouring process is as follows: (1) After the sand core 200 sets of cores are completed, mud strips 231 are placed around the circumference at the bottom groove 213 of the inner wall of the riser cavity 211 to form a closed loop; (2) The air vent of the heat insulation riser 230 is sealed with paper tape 232. The heat insulation riser 230 is placed in the riser cavity 211 and evenly distributed along the circumferential gap. (3) Screw the riser cover core 220 vertically into the top of the riser cavity 211 until the bottom of the riser cover core 220 contacts the top of the insulation riser 230; (4) Clean the loose sand inside the air outlet 222 and seal the two air outlets 222 with paper tape 232; (5) Pouring at the water inlet.

[0028] This invention solves the problems of displacement and low waiting efficiency of post-installed insulating risers. The anti-displacement riser cover core is organically integrated with the sand core cover core and the insulating riser to form a whole, effectively solving the riser displacement problem. Simultaneously, the anti-displacement riser cover core can be flexibly adjusted according to changes in the insulating riser size, offering strong versatility; various standard cover cores can be designed according to riser dimensions, facilitating on-site use, and utilizing printer idle space for printing, effectively saving costs. Connecting the insulating riser to the cover core through a specially structured sand core solves the problem of insulating riser displacement, eliminates waiting time, and effectively improves core assembly efficiency, providing a new direction for 3D printing of post-installed sand core risers and tooling.

[0029] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for assembling a heat-insulating riser core for casting, characterized in that, Includes the following steps: S1: After the sand core assembly is completed, mud strips are laid axially at the bottom groove of the inner wall of the riser cavity to form a closed mud strip ring; S2: Seal the vent of the thermal insulation riser with paper tape, and then put the thermal insulation riser into the riser cavity to make its circumferential gaps evenly distributed; S3: Screw the riser cover core with the vent groove into the riser cavity until the bottom of the riser cover core contacts the top of the insulation riser; S4: An air outlet is provided in the middle of the riser cover core. The loose sand in the air outlet of the riser cover core is cleaned, and the air outlet is sealed with paper tape. S5: Pouring at the water inlet.

2. The casting insulation riser core assembly process according to claim 1, characterized in that, The riser cap core is circumferentially threaded on its outer side, and the riser cap core is screwed in vertically along the threaded structure at the top of the riser cavity.

3. The casting insulation riser core assembly process according to claim 1, characterized in that, The thread pitch at the top of the riser cavity is 10 mm.

4. The casting insulation riser core assembly process according to claim 1, characterized in that, The vent groove is arranged radially along the riser cap core, and the vent groove is annular.

5. The casting insulation riser core assembly process according to claim 4, characterized in that, After the riser cover core is assembled, the vent hole of the heat-insulating riser is always located within the range of the vent groove.

6. The casting insulation riser core assembly process according to claim 4, characterized in that, The cross-sectional dimensions of the air outlet groove are 15mm × 15mm.

7. The casting insulation riser core assembly process according to claim 1, characterized in that, The riser cap core is 3D printed.

8. The casting insulation riser core assembly process according to claim 1, characterized in that, The mud strips are placed in a pre-set groove at the bottom of the cover core, and the outer diameter of the groove is 3mm larger than the outer diameter of the insulation riser.

9. The casting insulation riser core assembly process according to claim 1, characterized in that, The two vents of the riser cap core can be used as assembly grippers.

10. The casting insulation riser core assembly process according to claim 1, characterized in that, The size of the insulating riser is determined based on the casting module.

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