A conformal hierarchical water channel structure for casting molds based on additive manufacturing

Abstract

This invention relates to the field of casting mold technology and provides a conformal graded water channel structure for casting molds based on additive manufacturing. The structure includes: an inlet and an outlet connected to a primary water channel; a secondary water channel, where the primary water channel is divided into several secondary water channels, the number of which matches the number of cooling elements; and a tertiary water channel, where the secondary water channels are divided into several tertiary water channels, the number of which matches the number and area of ​​cooling surfaces. The tertiary water channels are conformal water channels surrounding the mold forming area. During water channel grading, if there are two sub-level water channels, a spherical diversion structure is used for grading; otherwise, staggered diversion pipes are used. This invention improves cooling uniformity, extends mold life, and enhances casting quality; it also reduces water channel structure bends, shortens the length of individual water channels, and facilitates powder removal during additive manufacturing post-processing.

Description

Technical Field

[0001] This invention belongs to the field of casting mold technology, and particularly relates to a conformal graded water channel structure for casting molds based on additive manufacturing. Background Technology

[0002] Casting molds are crucial tools for forming complex parts in industrial production, and their cooling systems directly impact production efficiency and product quality. Typically, the cooling water channels in casting molds are constrained by machining methods. Using mechanical drilling to create straight, circular water channels cannot tightly conform to the complex curved surfaces of the mold cavity. This cooling method, due to excessive temperature differences on the mold surface, easily creates localized hot spots in complex areas of the mold, affecting not only the quality of the castings but also shortening the mold's lifespan and impacting production efficiency.

[0003] The application of additive manufacturing technology in mold making has made the design of casting mold cooling systems more flexible. Compared with the straight water channels in machining, the water channel structure in additive manufacturing can be bent to conform to the shape of the mold surface, achieving conformal cooling. However, existing conformal cooling water channel structures based on additive manufacturing often adopt a single curved design with a uniform cross-sectional area from the inlet to the outlet. On the one hand, the water temperature increases in the area that the water flows through first, affecting the heat dissipation effect in the areas that flow through later, making it difficult to simultaneously cool multiple high-temperature areas. This results in a large temperature difference on the mold surface, making it difficult to achieve uniform cooling of complex three-dimensional cavities. On the other hand, the excessive length and multiple excessive bends of the single water channel in the mold make powder removal difficult during the post-processing of additive manufacturing.

[0004] In summary, the design of cooling systems for casting molds generally has three main problems: First, poor heat dissipation capacity of the mold leads to a low thermal fatigue life and affects production efficiency; second, uneven cooling of the castings easily causes sticking, shrinkage cavities, and cold shuts, affecting the quality of the castings; and third, in order to achieve uniform heat dissipation, the conformal cooling channels of molds based on additive manufacturing often adopt a multi-bending conformal design, which makes it difficult to remove powder in the post-processing of additive manufacturing. Summary of the Invention

[0005] The purpose of this invention is to provide a conformal graded water channel structure for casting molds based on additive manufacturing, in order to solve the problems mentioned in the background art.

[0006] The present invention is implemented as follows: a conformal hierarchical water channel structure for a casting mold based on additive manufacturing, comprising:

[0007] The inlet and outlet are respectively connected to the primary waterway;

[0008] The primary water circuit is divided into several secondary water circuits, and the number of secondary water circuits matches the number of cooling elements.

[0009] The secondary water channel is divided into several tertiary water channels. The number of tertiary water channels is matched with the number and area of ​​the cooling surface. The tertiary water channel is a conformal water channel surrounding the forming area of ​​the mold. The cooling medium enters the primary water channel from the inlet, is transported to different cooling bodies through the secondary water channel, and then undergoes heat exchange in the forming area through the tertiary water channel. After converging along the loop, it is discharged through the outlet.

[0010] When classifying water channels, if there are two water channels at the next level, a spherical diversion structure is used for classification; if there are more than two water channels at the next level, a staggered diversion pipeline classification is used.

[0011] This invention provides a conformal graded water channel structure for casting molds based on additive manufacturing. On the one hand, it fundamentally improves the cooling uniformity of the mold's three-dimensional space. The graded water channel can simultaneously cool multiple high-temperature areas while closely conforming to the mold surface. This avoids the influence between the areas through which the water flows due to a single reciprocating curved water channel structure, thus improving cooling uniformity, extending mold life, and enhancing casting quality. On the other hand, the conformal graded water channel can significantly reduce the curvature of the water channel structure. The water channels are all designed in a downward hanging manner from bottom to top, greatly reducing the length of a single water channel and making powder removal easier during the post-processing of additive manufacturing. Attached Figure Description

[0012] Figure 1 A schematic diagram of the application of a conformal graded water channel structure for a casting mold based on additive manufacturing in an embodiment of the present invention;

[0013] Figure 2 This is a schematic diagram of a conformal graded water channel structure for a casting mold based on additive manufacturing, provided in an embodiment of the present invention.

[0014] Figure 3 A schematic diagram of a spherical diversion structure in a conformal graded water channel structure for a casting mold based on additive manufacturing, provided as an embodiment of the present invention;

[0015] Figure 4 A schematic diagram of the branch pipe in a conformal graded water channel structure for a casting mold based on additive manufacturing, provided for an embodiment of the present invention;

[0016] Figure 5 A schematic diagram of the flow distribution direction in a conformal graded water channel structure of a casting mold based on additive manufacturing, provided for an embodiment of the present invention;

[0017] Figure 6 A front view of a conformal graded water channel structure for a casting mold based on additive manufacturing, provided in an embodiment of the present invention;

[0018] Figure 7The present invention provides a comparison of the cooling effects of the present invention and the prior art on the mold at 0s and 20s, respectively.

[0019] Figure 8 The present invention provides a comparison of the cooling effects on the mold at 40s and 60s between the embodiments of the present invention and the prior art.

[0020] Figure 9 The cooling effect of the mold using the embodiment of the present invention and the adjacent mold were compared at 0s, 20s, 40s and 60s respectively.

[0021] In the attached diagram: 1. Mold base; 2. Cooling body one; 3. Cooling body two; 4. Cooling surface one; 5. Cooling surface two; 6. Water inlet; 7. Primary water channel; 8. Spherical diversion structure; 9. Secondary water channel; 10. Diversion pipe; 11. Tertiary water channel; 12. Water outlet. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0024] like Figures 1 to 4 The diagram shown illustrates a structural design of a conformal graded water channel structure for a casting mold based on additive manufacturing, according to an embodiment of the present invention. The structure includes:

[0025] Inlet 6 and outlet 12, the inlet 6 and outlet 12 are respectively connected to the primary waterway 7;

[0026] The primary water channel 7 is divided into several secondary water channels 9, and the number of secondary water channels 9 matches the number of cooling bodies.

[0027] The third-level water channel 11 and the second-level water channel 9 are divided into several third-level water channels 11. The number of the third-level water channels 11 is matched with the number and area of ​​the cooling surface. The third-level water channels 11 are conformal water channels surrounding the mold forming area. The cooling medium enters the first-level water channel 7 from the inlet 6, is transported to different cooling bodies through the second-level water channel 9, and then undergoes heat exchange in the forming area through the third-level water channels 11. After converging along the loop, it is discharged through the outlet 12.

[0028] When classifying water channels, if there are two water channels at the next level, a spherical diversion structure of 8 is used for classification; if there are more than two water channels at the next level, a staggered diversion pipeline of 10 is used for classification.

[0029] In one embodiment of the present invention, the conformal hierarchical cooling channel structure for additive manufacturing casting mold addresses the problems raised in the prior art by proposing a design that integrates hierarchical and conformal cooling channels. It utilizes mold flow analysis to determine the key cooling requirements of the mold, thereby generating the optimal conformal cooling channel layout. Specifically:

[0030] The multi-stage branching waterway between inlet 6 and outlet 12 is not limited to a one-to-two split, but adopts a three-dimensional staggered graded structure. The cooling medium (industrial cooling water containing rust inhibitors can be selected) enters the primary waterway 7 from the vertically arranged inlet 6. The primary waterway 7 is divided into several secondary waterways 9 according to the number of cooling elements, such as... Figure 2 As shown, the mold base 1 has a cooling body 2 and a cooling body 3. Therefore, the primary water channel 7 is divided into two secondary water channels 9 by the spherical diversion structure 8. The cooling medium is transported to the cooling body 2 and the cooling body 3 through the secondary water channels 9. The secondary water channels 9 are then divided into tertiary water channels 11 according to the number and area of ​​the cooling surfaces 4 and 5 through the diversion pipe 10. The tertiary water channels 11 are conformal water channels surrounding the molding area of ​​the mold. After the medium has fully exchanged heat with the molding area, it converges along the water channel loop and is discharged through the outlet 12, entering the subsequent cooling medium circulation system (the embodiment of this invention does not involve the specific structure of the circulation system, but only focuses on the water channels inside the mold, so it is not described in detail).

[0031] If there are two water channels in the next stage, a spherical diversion structure with 8 stages is adopted. In the existing direct grading structure, the two grading water channels are directly intersected, which can easily cause a hanging structure. Additional support is required. After additive manufacturing, the support is not easy to remove. However, the spherical grading structure has a self-supporting effect, which avoids the difficulty of adding support structure and removing support after printing.

[0032] The inlet 6 and outlet 12 need to meet the flow requirements of the cooling medium and are the primary channels for circulation. The three-stage water channel 11 fits the mold forming surface, so that the cooling medium forms a surrounding cooling on the key forming area, improving uniformity. Through such water channel layout and operation, the cooling medium flows through the area to be cooled in a comprehensive and uniform manner, quickly removes heat, ensures that the mold temperature is suitable, and improves production stability, product quality and mold life.

[0033] like Figure 6 As shown, the cooling medium flows from part 1 of the mold base to the top forming area, and after heat exchange, it converges and flows back to the bottom. This graded water channel structure avoids the reciprocating bending of a single water channel, which is significantly beneficial to powder removal in the post-processing of mold additive manufacturing.

[0034] like Figure 5As shown, in a preferred embodiment of the present invention, the three-stage water channels 11 are staggered and graded, with the graded positions not at the same height and in the same plane direction. The direction of the division is parallel to the cooling surface, and the number of divisions matches the area of ​​the cooling surface.

[0035] Furthermore, the cross-sectional areas of the primary waterway 7, the secondary waterway 9, and the tertiary waterway 11 respectively satisfy the following formula:

[0036] ;

[0037] in, This represents the cross-sectional area of ​​the waterway at the next higher level. denoted by , where n represents the cross-sectional area of ​​the next level waterway, and n represents the number of next-level waterways branching off from the previous level waterway.

[0038] To ensure consistent flow rate and continuous heat exchange, the cross-sectional area of ​​each water channel must satisfy the above formula, which guarantees that the flow rate remains unchanged before and after the diversion.

[0039] The cross-sectional shape of the waterway is not limited to a circle; it can also be elliptical, fan-shaped, square, etc.

[0040] The conformal graded water channel structure was practically applied, and its cooling effect on the mold was compared with that of the existing water channel structure. The cooling performance of the two molds was compared, for example... Figure 7 , 8 As shown (the left side is an embodiment of the present invention, and the right side is the prior art); a comparison with the cooling situation of adjacent molds is provided. Figure 9 As shown (the left side is an embodiment of the present invention, and the right side is an adjacent mold), it can be seen that the mold using the conformal graded water channel structure of the present invention has a faster and better cooling speed.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An additive manufacturing based, as-cast, hierarchical waterway structure for a casting mold, characterized by, Comprise: Water inlet (6) and water outlet (12), the water inlet (6) and water outlet (12) are connected with primary waterway (7) respectively; Secondary waterway (9), primary waterway (7) is divided into several secondary waterways (9), the number of secondary waterway (9) matches the number of cooling body; Third waterway (11), secondary waterway (9) is divided into several third waterways (11), the number of third waterway (11) matches the number and area of cooling surface, third waterway (11) is a shaped waterway around the molding area of mold, cooling medium enters primary waterway (7) from water inlet (6), is transported to different cooling body through secondary waterway (9), and then is heat exchanged in molding area through third waterway (11), is gathered along the loop and is discharged through water outlet (12); When waterway is graded, if the number of next level waterway is two, spherical flow dividing structure (8) is used for grading, if the number of next level waterway is more than two, flow dividing pipeline (10) is used for staggered grading.

2. The additive manufacturing-based, as-cast, staged runner structure of claim 1, wherein, The third waterway (11) is staggered graded, the grading position is not on the same height and the same plane direction, the divided direction is parallel to the cooling surface, and the divided number matches the area of cooling surface.

3. The additive manufacturing-based, cast-mold conformal staged runner structure of claim 1, wherein, The cross-sectional area of primary waterway (7), secondary waterway (9) and third waterway (11) respectively meets the following formula: ； wherein, represents the cross-sectional area of the upper-stage waterway, represents the cross-sectional area of the lower-stage waterway, and n represents the number of lower-stage waterways branched from the upper-stage waterway.

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